ANTIBODIES TO FIBROBLAST ACTIVATION PROTEIN AND B7H3

Cross-Reference to Related Applications

This application claims the benefit under 35 U.S.C. § 119(e) to U.S. Provisional Application No. 63/040,124, filed June 17, 2020, which is incorporated by reference in its entirety.

Statement Regarding the Sequence Listing

The Sequence Listing associated with this application is provided in text format in lieu of a paper copy, and is hereby incorporated by reference into the specification. The name of the text file containing the Sequence Listing is PRVA_008_01WO_ST25.txt. The text file is about 933 KB, created on June 16, 2021, and is being submitted electronically via EFS-Web.

Background

Technical Field

The present disclosure relates to anti-fibroblast activation protein-a (FAPa or FAP) antibodies, and antigen-binding fragments thereof, including those having dual binding specificity for human FAP and human CD276 (B7H3), which may be used in any of a variety of therapeutic or diagnostic methods, including the treatment or diagnosis of oncological diseases and others.

Description of the Related Art

FAP expression is seen on activated stromal fibroblasts of more than 90% of all human carcinomas (see, for example, Pure et al., Oncogene. 37: 4343-4357, 2018; and Busek et al., Frontiers in Bioscience. 23:1933-1968, 2018). Stromal fibroblasts play an important role in the development, growth, and metastasis of carcinomas. Several approaches of FAP targeting mainly in cancer treatment are currently being tested including the use of low molecular weight inhibitors, prodrugs activated by FAP, various anti-FAP antibodies and their conjugates, FAP -CAR T cells, and FAP vaccines.

CD276 (B7H3) is an immune checkpoint molecule shows high expression on certain cancer cells, and relatively low expression on cells in healthy or normal tissue. Inhibition of the B7H3 immune checkpoint has been shown to reduce tumor growth, for example, by enhancing cytotoxic lymphocyte function (see, for example, Lee et al., Cell Research. 27: 1034-1045, 2017).

However, there remains a need in the art for therapeutic antibodies that effectively target FAP, alone or in combination with B7H3. Moreover, there are technical challenges associated with engineering an antibody with defined dual-specificity at a single paratope. Brief Summary

Certain embodiments include an isolated antibody, or an antigen-binding fragment thereof, which specifically binds to a human fibroblast activation protein-a (FAPa or FAP). In some embodiments, the isolated antibody, or antigen-binding fragment thereof, has dual binding specificity, and specifically binds to the human FAP and a human B7H3 protein at the same or substantially the same paratope.

In some embodiments, the isolated antibody, or antigen-binding fragment thereof, comprises: a heavy chain variable (V _H ) region comprising V _H CDR1, V _H CDR2, and V _H CDR3 regions selected from Table Al; and a light chain variable (V _L ) region comprising V _L CDR1, V _L CDR2, and V _L CDR3 regions selected from Table Al, or a variant of said antibody, or antigen-binding fragment thereof, which has up to 1, 2, 3, 4,

5, 6, 7, or 8 total amino acid substitutions across said CDR regions and retains specific binding activity.

In some embodiments: the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 1-3; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 4-6; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 7-9; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 10-12; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 13-15; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 16-18; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 19-21; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 22-24; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 25-27; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 28-30; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 31-33; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 34-36; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 37-39; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 40-42; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 43-45; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 46-48; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 49-51; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 52-54; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 55-57; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 58-60; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 61-63; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 64-66; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 67-69; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 70-72; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 73-75; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 76-78; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 79-81; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 82-84; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 85-87; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 88-90; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 91-93; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 94-96; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 97-99; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 100-102; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 103- 105; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 106-108; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 109- 111; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 112-114; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 115- 117; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 118-120; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 121- 123; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 124-126; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 127- 129; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 130-132; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: S S; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 136-138; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 139- 141; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 142-144; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 145- 147; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 148-150; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: OI OS; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 04-06; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 07- 09; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 160-162; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 163- 165; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 166-168; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 169- 171; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 172-174; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 175-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 178-180; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 181-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 184-186; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 187-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 190-192; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 193-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 196-198; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 199-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 202-204; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 205-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 208-210; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 211-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 214-216; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 217-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 220-222; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 223-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 226-228; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 229-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 232-234; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 235-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 238-240; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 241-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 244-246; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 247-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 250-252; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 253-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 256-258; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 259-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 262-264; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 265-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 268-270; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 271-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 274-276; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 277-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 280-282; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 283-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 286-288; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 289-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 292-294; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 295-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 298-300; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 301-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 304-306; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 307-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 310-312; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 313-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 316-318; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 319-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 322-324; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 325-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 328-330; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 331-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 334-336; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 337-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 340-342; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 343-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 346-348; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 349-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 352-354; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 355-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 358-360; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 361-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 364-366; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 367-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 370-372; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 373-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 376-378; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 379-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 382-384; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 385-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 388-390; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 391-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 394-396; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 397-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 400-402; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 403-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 406-408; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 409-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 412-414; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 415-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 418-420; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 421-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 424-426; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 427-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 430-432; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 433-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 436-438; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 439-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 442-444; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 445-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 448-450; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 451-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 454-456; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 457-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 460-462; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 463-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 466-468; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 469-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 472-474; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 475-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 478-480; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 481-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 484-486; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 487-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 490-492; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 493-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 496-498; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 499-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 502-504; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 505-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 508-510; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 511-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 514-516; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 517-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 520-522; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 523-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 526-528; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 529-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 532-534; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 535-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 538-540; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 541-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 544-546; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 547-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 550-552; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 553-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 556-558; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 559-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 562-564; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 565-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 568-570; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 571-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 574-576; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 577-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 580-582; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 583-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 586-588; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 589-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 592-594; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 595-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 598-600; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 601-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 604-606; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 607-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 610-612; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 613-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 616-618; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 619-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 622-624; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 625-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 628-630; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 631 -; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 634-636; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 637-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 640-642; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 643-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 646-648; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 649-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 652-654; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 655-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 658-660; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 661 -; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 664-666; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 667 -; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 670-672; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 673-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 676-678; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 679-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 682-684; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 685-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 688-690; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 691-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 694-696; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 697-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 700-702; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 703-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 706-708; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 709-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 712-714; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 715- 717; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 718-720; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 721- 723; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 724-726; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 727- 729; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 730-732; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 733- 735; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 736-738; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 739- 741; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 742-744; or the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 745- 747; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 748-750.

In some embodiments, the heavy chain is at least 80, 85, 90, 95, 97, 98, 99, or 100% identical to a sequence selected from Table A2, optionally wherein the heavy chain has 1, 2, 3, 4, 5, or 6 alterations in the framework regions. In some embodiments, the light chain is at least 80, 85, 90, 95, 97, 98, 99, or 100% identical to a sequence selected from Table A2, optionally wherein the light chain has 1, 2, 3, 4, 5, or 6 alterations in the framework regions.

In some embodiments: the heavy chain comprises a sequence at least 80, 85, 90, 95, 97, 98, 99, or 100% identical to SEQ ID NO: 751, 753, 755, 757, 759, 761, 763, 765, 767, 769, 771, 773, 775, 777, 779, 781, 783, 785, 787, 789, 791, 793, 795, 797, 799, 801, 803, 805, 807, 809, 811, 813, 815, 817, 819, 821, 823,

825, 827, 829, 831, 833, 835, 837, 839, 841, 843, 845, 847, 849, 851, 853, 855, 857, 859, 861, 863,

865, 867, 869, 871, 873, 875, 877, 879, 881, 883, 885, 887, 889, 891, 893, 895, 897, 899, 901, 903,

905, 907, 909, 911, 913, 915, 917, 919, 921, 923, 925, 927, 929, 931, 933, 935, 937, 939, 941, 943,

945, 947, 949, 951, 953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983,

985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, or 1005; and the light chain respectively comprises a sequence at least 80, 85, 90, 95, 97, 98, 99, or 100% identical to SEQ ID NO: 752, 754, 756, 758, 760, 762, 764, 766, 768, 770, 772, 774, 776, 778, 780, 782, 784, 786, 788, 790, 792, 794, 796, 798, 800, 802, 804, 806, 808, 810, 812, 814, 816, 818,

820, 822, 824, 826, 828, 830, 832, 834, 836, 838, 840, 842, 844, 846, 848, 850, 852, 854, 856, 858,

860, 862, 864, 866, 868, 870, 872, 874, 876, 878, 880, 882, 884, 886, 888, 890, 892, 894, 896, 898,

900, 902, 904, 906, 908, 910, 912, 914, 916, 918, 920, 922, 924, 926, 928, 930, 932, 934, 936, 938,

940, 942, 944, 946, 948, 950, 952, 954, 956, 958, 960, 962, 964, 966, 968, 970, 972, 974, 976, 978,

980, 982, 984, 986, 988, 990, 992, 994, 996, 998, 1000, 1002, 1004, or 1006.

In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, specifically binds to human FAP and human B7H3 with comparable binding affinities, for example, wherein the binding affinities for FAP and B7H3 are about or less than about 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 20-fold relative to each other. In some embodiments, the isolated antibody, or an antigen binding fragment thereof, binds to cell surface-expressed human FAP, and optionally cell surface- expressed human B7H3. In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, specifically binds to at least one human FAP peptide epitope selected from Table Tl, and which optionally specifically binds to at least one human B7H3 peptide epitope selected from Table T2. In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, is a monoclonal antibody and/or a humanized antibody, or an antigen-binding fragment thereof. In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, is a whole antibody, a fragment antigen-binding domain (Fab), a F(ab’)2 domain, a single-chain variable fragment (scFv), a dimeric single-chain variable fragment (di-scFv), a single domain antibody (sdAb), or a bi-specific or multi-specific antibody.

In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, comprises an Fc region selected from an IgA (including subclasses IgAl and IgA2), IgD, IgE, IgG (including subclasses IgGl, IgG2, IgG3, and IgG4), and IgM Fc region, optionally a human Fc region, including hybrids and variants thereof. In some embodiments, the isolated antibody, or an antigen binding fragment thereof, comprises an IgG Fc region with high effector function in humans, optionally an IgGl Fc region or an IgG3 Fc region. In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, comprises an IgG Fc region with low effector function in humans, optionally an IgG2 Fc region or an IgG4 Fc region. In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, comprises a modified Fc region which has at least one altered effector function and/or pharmacokinetic (PK) characteristic relative to a wild-type Fc region.

In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, specifically binds to the human FAP with a K _D of 0.4 nM or lower, and which specifically binds to the human B7H3 protein with a K _D of 0.4 nM or lower.

In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, is a bi specific or multi-specific antibody, comprising a first anti-FAP and/or antiB7H3 Fab region as described herein, and a second Fab region that specifically binds to an additional antigen, for example, a cell surface antigen/receptor expressed on an immune cell or cancer cell, such as CD3.

In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, is fused via an optional linker to a heterologous effector domain. In some embodiments, the heterologous effector domain comprises an immune cell-stimulatory ligand or domain, an immune cell-inhibitory ligand or domain, or a cytocidal (e.g., tumor cell cytocidal) ligand or domain, optionally selected from interleukin-2 (IL-2), interleukin- 15 (IL-15), hybrid IL-2/IL-15, and a TNF superfamily ligand such as TRAIL, 4-1BBL, interleukin-21 (IL-21), IFN-alpha, IFN-beta, CD40, GITR-L, OX40L, and CD70. In some embodiments, the isolated antibody, or an antigen-binding fragment thereof, is a single-chain variable fragment (scFv) fused via a spacer (hinge) region to a transmembrane domain and an intracellular T-cell signaling domain, to form a chimeric antigen receptor (CAR).

Also included are isolated polynucleotides encoding an isolated antibody, or antigen-binding fragment thereof, described herein, an expression vector comprising the isolated polynucleotide, or an isolated host cell comprising the vector. Also included are methods of producing an antibody, or an antigen-binding fragment thereof, as described herein, comprising culturing the host cell under culture conditions suitable for the expression of the antibody, or antigen-binding fragment thereof, and isolating the antibody, or antigen-binding fragment thereof, from the culture.

Some embodiments include a chimeric antigen receptor (CAR) T cell, comprising a CAR described herein.

Certain embodiments include a pharmaceutical composition, comprising a physiologically acceptable carrier and an antibody, or antigen-binding fragment thereof, or a CAR T cell, as described herein.

Certain embodiments include a method for treating a disease in a subject in need thereof, comprising administering to the subject the pharmaceutical composition, as described herein. In some embodiments, the disease is a cancer. In some embodiments, the subject has, or is selected for treatment based on having, a cancer associated with increased or aberrant FAP expression. In some embodiments, the subject has, or is selected for treatment based on having, a cancer associated with increased or aberrant B7H3 expression. In some embodiments, the cancer is a primary cancer or a metastatic cancer, and is selected from one or more of melanoma (optionally metastatic melanoma), kidney cancer (optionally renal cell carcinoma), pancreatic cancer, bone cancer, prostate cancer, small cell lung cancer, non-small cell lung cancer (NSCLC), mesothelioma, leukemia (optionally lymphocytic leukemia, chronic myelogenous leukemia, acute myeloid leukemia, or relapsed acute myeloid leukemia), multiple myeloma, lymphoma, hepatoma (hepatocellular carcinoma), sarcoma, B- cell malignancy, breast cancer, ovarian cancer, colorectal cancer, glioma, glioblastoma multiforme, meningioma, pituitary adenoma, vestibular schwannoma, primary CNS lymphoma, primitive neuroectodermal tumor (medulloblastoma), bladder cancer, uterine cancer, esophageal cancer, brain cancer, head and neck cancers, cervical cancer, testicular cancer, thyroid cancer, and stomach cancer.

In some embodiments, the metastatic cancer is selected from one or more of:

(a) a bladder cancer which has metastasized to the bone, liver, and/or lungs;

(b) a breast cancer which has metastasized to the bone, brain, liver, and/or lungs;

(c) a colorectal cancer which has metastasized to the liver, lungs, and/or peritoneum;

(d) a kidney cancer which has metastasized to the adrenal glands, bone, brain, liver, and/or lungs;

(e) a lung cancer which has metastasized to the adrenal glands, bone, brain, liver, and/or other lung sites; (f) a melanoma which has metastasized to the bone, brain, liver, lung, and/or skin/muscle;

(g) a ovarian cancer which has metastasized to the liver, lung, and/or peritoneum;

(h) a pancreatic cancer which has metastasized to the liver, lung, and/or peritoneum; a prostate cancer which has metastasized to the adrenal glands, bone, liver, and/or lungs;

CD a stomach cancer which has metastasized to the liver, lung, and/or peritoneum;

CD a thyroid cancer which has metastasized to the bone, liver, and/or lungs; and

(m) a uterine cancer which has metastasized to the bone, liver, lung, peritoneum, and/or vagina.

In some embodiments, the antibody, or antigen-binding fragment thereof, enhances an immune response to the cancer by about, or at least about, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000% or more, relative to a control. In some embodiments, the antibody, or antigen-binding fragment thereof, increases cancer cell killing in the subject by about or at least about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200,

300, 400, 500, 600, 700, 800, 900, 1000, 2000% or more relative to an untreated control. In some embodiments, the antibody, or antigen-binding fragment thereof, reduces invasiveness of the cancer by about or at least about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000% or more relative to an untreated control.

Certain embodiments include administering to the subject in need thereof an additional agent selected from one or more of a cancer immunotherapy agent, a chemotherapeutic agent, a hormonal therapeutic agent, and a kinase inhibitor. In some embodiments, the antibody, or antigen-binding fragment thereof, and the additional agent are administered separately, as separate compositions. In some embodiments, the antibody, or antigen-binding fragment thereof, and the additional are administered together as part of the same pharmaceutical composition. In some embodiments, the antibody, or antigen-binding fragment thereof, enhances susceptibility of the cancer to the additional agent by about or at least about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000% or more relative to the additional agent alone.

Some embodiments include administering the pharmaceutical composition to the subject by parenteral administration. In some embodiments, the parenteral administration is intravenous administration.

Certain embodiments include the use of a pharmaceutical composition as described herein in the preparation of a medicament for treating a disease in a subject, optionally wherein the disease is a cancer, optionally wherein the cancer is associated with increased or aberrant FAP and/or B7H3 expression. Also included is pharmaceutical composition as described herein for use in treating a disease in a subject, optionally wherein the disease is a cancer, optionally wherein the cancer is associated with increased or aberrant FAP and/or B7H3 expression. Brief Description of the Drawings

Figure 1 illustrates a “dual action” fragment antigen binding (Fab) region that specifically binds to human fibroblast activation protein (FAP) or human CD276 (B7H3), but not both simultaneously, at the same or substantially the same paratope.

Figure 2 illustrates a “dual action” whole antibody that specifically binds to human FAP and human B7H3 at each of its separate but otherwise identical Fab regions. It is also possible that each of the two Fab regions bind only to FAP or only to B7H3.

Figure 3 illustrates a bi-specific or multi-specific version of a “dual action” antibody, where one Fab region specifically binds to human FAP or human B7H3 at the same or substantially the same paratope, and the other Fab region specifically binds to a third antigen, including a cell surface antigen such as CD3 (depicted) expressed on T cells, NK cells, DCs, macrophages, or tumor cells.

Figures 4A-4F illustrate the fusion (4A-4E) or chemical conjugation (4F) of a “dual action” Fab or whole antibody to one or more heterologous effector domains or other molecules, such as small molecule toxins, proteinacous toxins, DNA or RNA molecules, or aptamers.

Figure 5 illustrates a chimeric antigen receptor (CAR) composed of a “dual action” scFv region that specifically binds to human FAP or B7H3 at the same or substantially the same paratope.

Figures 6A-6C show reduced SDS-PAGE analysis of Expi293 expression supernatant (6A), non-reduced SDS-PAGE analysis (6B), and reduced SDS-PAGE analysis (6C) of purified antibodies. “M” on the figures represents the protein standard marker.

Figures 7A-7F illustrate representative HPLC analysis results of exemplary antibodies purified using protein affinity chromatography.

Figures 8A-8L show dose dependent binding activity and specificity of Expi293 expression supernatant against human FAPa protein.

Figures 9A-9Q show dose dependent binding activity and specificity of Expi293 expression supernatant against human FAPa (9A-90), cyno FAPa (9P) and mouse FAPa (9Q).

Figures 10A-10Q show dose dependent binding activity and specificity of Expi293 expression supernatant against human B7H3-L.

Figures 11A-11R show dose dependent binding activity and specificity of Expi293 expression supernatant against human B7H3-S.

Figures 12A-12L show dose dependent binding activity and specificity of Expi293 expression supernatant against cyno B7H3-L (12A-12F) and cyno B7H3-S (12G-12L).

Figures 13A-13F show dose dependent binding activity and specificity of Expi293 expression supernatant against mouse B7H3-S.

Figures 14A-14N show dose dependent binding activity of purified antibodies against human FAPa (14A-14E), human B7H3-L (14F-14J), human B7H3-S (14K), cyno B7H3-L (14L), cyno B7H3-S (14M), and mouse B7H3-S (14N). Figures 15A-15I show FACS binding of purified antibodies to cells expressing FAP or

B7H3.

Figures 16A-16I show FACS binding of Expi293F expression supernatant to cells expressing FAP or B7H3.

Figures 17A-17I show FACS binding of purified antibodies to cells expressing FAP or

B7H3.

Figures 18A-18L shows the amino acid sequence of variable region of exemplary antibodies. Figures 18 A, 18C, 18D, 18G, 181, 18J, 18K, and 18L show the alignment of heavy chain variable region sequences. Figures 18B, 18E, 18F, and 18H show the alignment of light chain variable region sequences.

Detailed Description

The present disclosure relates to antibodies, and antigen-binding fragments thereof, which specifically bind to fibroblast activation protein (FAP), and “dual-action” antibodies, including those having dual binding specificity for FAP and human CD276 (B7H3) at the same or substantially the same paratope, and related pharmaceutical compositions, cells, and methods of use thereof. The antibodies, and antigen-binding fragments thereof, of the present disclosure, can find utility as standalone therapeutic, diagnostic, or research agents, or as part of a fusion protein or chimeric antigen receptor, as described herein.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the disclosure belongs. Although any methods, materials, compositions, reagents, cells, similar or equivalent similar or equivalent to those described herein can be used in the practice or testing of the subject matter of the present disclosure, preferred methods and materials are described. All publications and references, including but not limited to patents and patent applications, cited in this specification are herein incorporated by reference in their entirety as if each individual publication or reference were specifically and individually indicated to be incorporated by reference herein as being fully set forth. Any patent application to which this application claims priority is also incorporated by reference herein in its entirety in the manner described above for publications and references.

Standard techniques may be used for recombinant DNA, oligonucleotide synthesis, and tissue culture and transformation (e.g., electroporation, lipofection). Enzymatic reactions and purification techniques may be performed according to manufacturer’s specifications or as commonly accomplished in the art or as described herein. These and related techniques and procedures may be generally performed according to conventional methods well known in the art and as described in various general and more specific references that are cited and discussed throughout the present specification. Unless specific definitions are provided, the nomenclature utilized in connection with, and the laboratory procedures and techniques of, molecular biology, analytical chemistry, synthetic organic chemistry, and medicinal and pharmaceutical chemistry described herein are those well- known and commonly used in the art. Standard techniques may be used for recombinant technology, molecular biological, microbiological, chemical syntheses, chemical analyses, pharmaceutical preparation, formulation, and delivery, and treatment of patients.

For the purposes of the present disclosure, the following terms are defined below.

The articles “a” and “an” are used herein to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article. By way of example, “an element” includes “one element”, “one or more elements” and/or “at least one element”.

By “about” is meant a quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length that varies by as much as 30, 25, 20, 15, 10, 9, 8, 7, 6, 5, 4, 3, 2 or 1% to a reference quantity, level, value, number, frequency, percentage, dimension, size, amount, weight or length.

An “antagonist” refers to biological structure (e.g., antibody) or chemical agent that interferes with or otherwise reduces the physiological action of another agent or molecule. In some instances, the antagonist specifically binds to the other agent or molecule. Included are full and partial antagonists.

An “agonist” refers to biological structure (e.g., antibody) or chemical agent that increases or enhances the physiological action of another agent or molecule. In some instances, the agonist specifically binds to the other agent or molecule. Included are full and partial agonists.

As used herein, the term “amino acid” is intended to mean both naturally occurring and non- naturally occurring amino acids as well as amino acid analogs and mimetics. Naturally -occurring amino acids include the 20 (L)-amino acids utilized during protein biosynthesis as well as others such as 4-hydroxyproline, hydroxylysine, desmosine, isodesmosine, homocysteine, citrulline and ornithine, for example. Non-naturally occurring amino acids include, for example, (D)-amino acids, norleucine, norvaline, p-fluorophenylalanine, ethionine and the like, which are known to a person skilled in the art. Amino acid analogs include modified forms of naturally and non-naturally occurring amino acids. Such modifications can include, for example, substitution or replacement of chemical groups and moieties on the amino acid or by derivatization of the amino acid. Amino acid mimetics include, for example, organic structures which exhibit functionally similar properties such as charge and charge spacing characteristic of the reference amino acid. For example, an organic structure which mimics arginine (Arg or R) would have a positive charge moiety located in similar molecular space and having the same degree of mobility as the e-amino group of the side chain of the naturally occurring Arg amino acid. Mimetics also include constrained structures so as to maintain optimal spacing and charge interactions of the amino acid or of the amino acid functional groups. Those skilled in the art know or can determine what structures constitute functionally equivalent amino acid analogs and amino acid mimetics. As used herein, the term “antibody” encompasses not only intact polyclonal or monoclonal antibodies, but also fragments thereof (such as dAb, Fab, Fab’, F(ab’)2, Fv), single chain (ScFv), synthetic variants thereof, naturally occurring variants, fusion proteins comprising an antibody portion with an antigen-binding fragment of the required specificity, humanized antibodies, chimeric antibodies, and any other modified configuration of the immunoglobulin molecule that comprises an antigen-binding site or fragment (epitope recognition site) of the required specificity. Certain features and characteristics of antibodies (and antigen-binding fragments thereof) are described in greater detail herein.

An antibody or antigen-binding fragment can be of essentially any type. As is well known in the art, an antibody is an immunoglobulin molecule capable of specific binding to a target through at least one epitope recognition site, located in the variable region of the immunoglobulin molecule.

The term “antigen-binding fragment” as used herein refers to a polypeptide fragment that contains at least one CDR of an immunoglobulin heavy and/or light chain that binds to the antigen of interest. In this regard, an antigen-binding fragment of the herein described antibodies may comprise 1, 2, 3, 4, 5, or all 6 CDRs of a VH and VL region from antibodies that bind to a target molecule.

The term “antigen” refers to a molecule or a portion of a molecule capable of being bound by a selective binding agent, such as an antibody, and additionally capable of being used in an animal to produce antibodies capable of binding to an epitope of that antigen. An antigen may have one or more epitopes. As used herein, the term “antigen” includes substances that are capable, under appropriate conditions, of inducing an immune response to the substance and of reacting with the products of the immune response. More broadly, the term “antigen” includes any substance to which an antibody binds, or for which antibodies are desired, regardless of whether the substance is immunogenic. For such antigens, antibodies can be identified by recombinant methods, independently of any immune response.

An “epitope” includes that portion of an antigen or other macromolecule capable of forming a binding interaction that interacts with the variable region binding pocket of an antibody, or antigen binding fragment thereof. Such binding interaction can be manifested as an intermolecular contact with one or more amino acid residues of a CDR. Antigen binding can involve a CDR3 or a CDR3 pair. An epitope can be a linear peptide sequence (i.e., “continuous”) or can be composed of noncontiguous amino acid sequences (i.e., “conformational” or “discontinuous”). An antibody, or antigen-binding fragment thereof, can recognize one or more amino acid sequences; therefore an epitope can define more than one distinct amino acid sequence. Epitopes can be determined, for examle, by peptide mapping and sequence analysis techniques well known to one of skill in the art. In particular embodiments, an epitope comprises, consists, or consists essentially of about, at least about, or no more than about 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 contiguous amino acids (i.e., a linear epitope) or non-contiguous amino acids (i.e., conformational epitope) of a reference sequence or target molecule described herein. A “paratope”, also called an antigen-binding site, refers to the part of an immunoglobulin that recognizes and binds to an antigen or antigens. In some instances, a paratope is a small region (e.g., of about 5 to 10 amino acids) within the fragment antigen-binding (Fab) region of an immunoglobulin, and includes a set of six complementarity-determining regions (CDR loops).

The binding properties of antibodies and antigen-binding fragments thereof can be quantified using methods well known in the art (see Davies et al., Annual Rev. Biochem. 59:439-473, 1990). In some embodiments, an antibody or antigen-binding fragment thereof specifically binds to a target molecule, for example, a cell surface receptor, a cancer or immunomodulatory antigen, or an epitope or complex thereof, with an equilibrium dissociation constant that is about or ranges from about <10 ⁷ M to about 10 ⁸ M. In some embodiments, the equilibrium dissociation constant is about or ranges from about <10 ⁹ M to about <10 ¹⁰ M. In certain embodiments, an antibody or antigen-binding fragment thereof has an affinity (Kd or EC50) for a target molecule (to which it specifically binds) of about, at least about, or less than about, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 40, or 50 nM.

A molecule such as a polypeptide or antibody is said to exhibit “specific binding” or “preferential binding” if it reacts or associates more frequently, more rapidly, with greater duration and/or with greater affinity with a particular cell(s), substance(s), or particular epitope(s) than it does with alternative cells or substances, or epitopes. An antibody “specifically binds” or “preferentially binds” to a target molecule or epitope if it binds with greater affinity, avidity, more readily, and/or with greater duration than it binds to other substances or epitopes, for example, by a statistically significant amount. Typically one member of the pair of molecules that exhibit specific binding has an area on its surface, or a cavity, which specifically binds to and is therefore complementary to a particular spatial and/or polar organization of the other member of the pair of molecules. Thus, the members of the pair have the property of binding specifically to each other. For instance, an antibody that specifically or preferentially binds to a specific epitope is an antibody that binds that specific epitope with greater affinity, avidity, more readily, and/or with greater duration than it binds to other epitopes. It is also understood by reading this definition that, for example, an antibody (or moiety or epitope) that specifically or preferentially binds to a first target may or may not specifically or preferentially bind to a second target. The term is also applicable where, for example, an antibody is specific for a particular epitope which is carried by a number of antigens, in which case the specific binding member carrying the antigen-binding fragment or domain will be able to bind to the various antigens carrying the epitope; for example, it may be cross reactive to a number of different forms of a target antigen from multiple species that share a common epitope

Immunological binding generally refers to the non-covalent interactions of the type which occur between an immunoglobulin molecule and an antigen for which the immunoglobulin is specific, for example by way of illustration and not limitation, as a result of electrostatic, ionic, hydrophilic and/or hydrophobic attractions or repulsion, steric forces, hydrogen bonding, van der Waals forces, and other interactions. The strength, or affinity of immunological binding interactions can be expressed in terms of the dissociation constant (Kd) of the interaction, wherein a smaller Kd represents a greater affinity. Immunological binding properties of selected polypeptides can be quantified using methods well known in the art. One such method entails measuring the rates of antigen-binding site/antigen complex formation and dissociation, wherein those rates depend on the concentrations of the complex partners, the affinity of the interaction, and on geometric parameters that equally influence the rate in both directions. Thus, both the “on rate constant” (Kon) and the “off rate constant” (Kofi) can be determined by calculation of the concentrations and the actual rates of association and dissociation. The ratio of Koff /Kon enables cancellation of all parameters not related to affinity, and is thus equal to the dissociation constant Kd. As used herein, the term “affinity” includes the equilibrium constant for the reversible binding of two agents and is expressed as Kd or EC _5O . Affinity of a binding protein to a ligand such as affinity of an antibody for an epitope can be, for example, from about 100 nanomolar (nM) to about 0.1 nM, from about 100 nM to about 1 picomolar (pM), or from about 100 nM to about 1 femtomolar (fM). As used herein, the term “avidity” refers to the resistance of a complex of two or more agents to dissociation after dilution. In some embodiments, affinity is expressed in the terms of the half maximal effective concentration (EC50), which refers to the concentration of an agent, such as an antibody, as disclosed herein, which induces a response halfway between the baseline and maximum after a specified exposure time. The EC50 is commonly used as a measure of an antibody’s potency.

Antibodies may be prepared by any of a variety of techniques known to those of ordinary skill in the art. See, e.g., Harlow and Lane, Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory, 1988. Monoclonal antibodies specific for a polypeptide of interest may be prepared, for example, using the technique of Kohler and Milstein, Eur. J. Immunol. 6:511-519, 1976, and improvements thereto. Also included are methods that utilize transgenic animals such as mice to express human antibodies. See, e.g., Neuberger et ak, Nature Biotechnology 14:826, 1996; Lonberg et ak, Handbook of Experimental Pharmacology 113:49-101, 1994; and Lonberg et ak, Internal Review of Immunology 13:65-93, 1995. Particular examples include the VELOCIMMUNE® platform by REGENEREX® (see, e.g., U.S. Patent No. 6,596,541).

Antibodies can also be generated or identified by the use of phage display or yeast display libraries (see, e.g., U.S. Patent No. 7,244,592; Chao et ak, Nature Protocols. 1:755-768, 2006). Nonlimiting examples of available libraries include cloned or synthetic libraries, such as the Human Combinatorial Antibody Library (HuCAL), in which the structural diversity of the human antibody repertoire is represented by seven heavy chain and seven light chain variable region genes. The combination of these genes gives rise to 49 frameworks in the master library. By superimposing highly variable genetic cassettes (CDRs = complementarity determining regions) on these frameworks, the vast human antibody repertoire can be reproduced. Also included are human libraries designed with human-donor-sourced fragments encoding a light-chain variable region, a heavy-chain CDR-3, synthetic DNA encoding diversity in heavy-chain CDR-1, and synthetic DNA encoding diversity in heavy-chain CDR-2. Other libraries suitable for use will be apparent to persons skilled in the art.

In certain embodiments, antibodies and antigen-binding fragments thereof as described herein include a heavy chain and a light chain CDR set, respectively interposed between a heavy chain and a light chain framework region (FR) set which provide support to the CDRs and define the spatial relationship of the CDRs relative to each other. As used herein, the term “CDR set” refers to the three hypervariable regions of a heavy or light chain V region. Proceeding from the N-terminus of a heavy or light chain, these regions are denoted as “CDR1,” “CDR2,” and “CDR3” respectively. An antigen binding site, therefore, includes six CDRs, comprising the CDR set from each of a heavy and a light chain V region. A polypeptide comprising a single CDR, (e.g., a CDR1, CDR2 or CDR3) is referred to herein as a “molecular recognition unit.” Crystallographic analysis of a number of antigen-antibody complexes has demonstrated that the amino acid residues of CDRs form extensive contact with bound antigen, wherein the most extensive antigen contact is with the heavy chain CDR3. Thus, the molecular recognition units are primarily responsible for the specificity of an antigen-binding site.

As used herein, the term “FR set” refers to the four flanking amino acid sequences which frame the CDRs of a CDR set of a heavy or light chain V region. Some FR residues may contact bound antigen; however, FRs are primarily responsible for folding the V region into the antigen binding site, particularly the FR residues directly adjacent to the CDRs. Within FRs, certain amino residues and certain structural features are very highly conserved. In this regard, all V region sequences contain an internal disulfide loop of around 90 amino acid residues. When the V regions fold into a binding-site, the CDRs are displayed as projecting loop motifs which form an antigen binding surface. It is generally recognized that there are conserved structural regions of FRs which influence the folded shape of the CDR loops into certain “canonical” structures — regardless of the precise CDR amino acid sequence. Further, certain FR residues are known to participate in non- covalent interdomain contacts which stabilize the interaction of the antibody heavy and light chains.

The structures and locations of immunoglobulin variable domains may be determined by reference to Rabat, E. A. et ak, Sequences of Proteins of Immunological Interest. 4th Edition. US Department of Health and Human Services. 1987, and updates thereof.

Also include are “monoclonal” antibodies, which refer to a homogeneous antibody population wherein the monoclonal antibody is comprised of amino acids (naturally occurring and non-naturally occurring) that are involved in the selective binding of an epitope. Monoclonal antibodies are highly specific, being directed against a single epitope. The term “monoclonal antibody” encompasses not only intact monoclonal antibodies and full-length monoclonal antibodies, but also fragments thereof (such as Fab, Fab’, F(ab’)2, Fv), single chain (ScFv), variants thereof, fusion proteins comprising an antigen-binding portion, humanized monoclonal antibodies, chimeric monoclonal antibodies, and any other modified configuration of the immunoglobulin molecule that comprises an antigen-binding fragment (epitope recognition site) of the required specificity and the ability to bind to an epitope. It is not intended to be limited as regards the source of the antibody or the manner in which it is made (e.g., by hybridoma, phage selection, recombinant expression, transgenic animals). The term includes whole immunoglobulins as well as the fragments etc. described above under the definition of “antibody.”

The proteolytic enzyme papain preferentially cleaves IgG molecules to yield several fragments, two of which (the F(ab) fragments) each comprise a covalent heterodimer that includes an intact antigen-binding site. The enzyme pepsin is able to cleave IgG molecules to provide several fragments, including the F(ab’)2 fragment which comprises both antigen-binding sites. An Fv fragment for use according to certain embodiments can be produced by preferential proteolytic cleavage of an IgM, and on rare occasions of an IgG or IgA immunoglobulin molecule. Fv fragments are, however, more commonly derived using recombinant techniques known in the art. The Fv fragment includes a non-covalent VH::VL heterodimer including an antigen-binding site which retains much of the antigen recognition and binding capabilities of the native antibody molecule. See Inbar et al., PNAS USA. 69:2659-2662, 1972; Hochman et al., Biochem. 15:2706-2710, 1976; and Ehrlich et al., Biochem. 19:4091-4096, 1980.

In certain embodiments, single chain Fv (scFV) antibodies are contemplated. For example, Kappa bodies (Ill et al., Prot. Eng. 10:949-57, 1997); minibodies (Martin et al., EMBO J 13:5305-9, 1994); diabodies (Holliger et al., PNAS 90: 6444-8, 1993); or Janusins (Traunecker et al., EMBO J 10: 3655-59, 1991; and Traunecker et al., Int. J. Cancer Suppl. 7:51-52, 1992), may be prepared using standard molecular biology techniques following the teachings of the present application with regard to selecting antibodies having the desired specificity.

A single chain Fv (scFv) polypeptide is a covalently linked VH::VL heterodimer which is expressed from a gene fusion including VH- and VL-encoding genes linked by a peptide-encoding linker. Huston et al. (PNAS USA. 85(16):5879-5883, 1988). A number of methods have been described to discern chemical structures for converting the naturally aggregated — but chemically separated — light and heavy polypeptide chains from an antibody V region into an scFv molecule which will fold into a three dimensional structure substantially similar to the structure of an antigen binding site. See, e.g., U.S. Pat. Nos. 5,091,513 and 5,132,405, to Huston et al.; and U.S. Pat. No. 4,946,778, to Ladner et al.

Certain embodiments include “probodies”, or antibodies where the binding site(s) are masked or otherwise inert until activated by proteolytic cleavage in target or disease tissue. Certain of these and related embodiments comprise one or more masking moieties that sterically hinder the antigen binding site(s) of the antibody, and which are fused to the antibody via one or more proteolytically- cleavable linkers (see, for example, Polu and Lowman, Expert Opin. Biol. Ther. 14:1049-1053, 2014).

In certain embodiments, an antibody as described herein is in the form of a diabody.

Diabodies are multimers of polypeptides, each polypeptide comprising a first domain comprising a binding region of an immunoglobulin light chain and a second domain comprising a binding region of an immunoglobulin heavy chain, the two domains being linked ( e.g . , by a peptide linker) but unable to associate with each other to form an antigen-binding site: antigen-binding sites are formed by the association of the first domain of one polypeptide within the multimer with the second domain of another polypeptide within the multimer (WO94/13804).

A dAb fragment of an antibody consists of a VH domain (Ward, E. S. et al, Nature 341, 544- 546 (1989)).

Where bispecific or multi-specific antibodies are to be used, these may be conventional bispecific antibodies, which can be manufactured in a variety of ways (Holliger and Winter, Current Opinion Biotechnol. 4:446-449, 1993), e.g., prepared chemically or from hybrid hybridomas, or may be any of the bispecific antibody fragments mentioned above. Diabodies and scFv can be constructed without an Fc region, using only variable domains, potentially reducing the effects of anti-idiotypic reaction. Bispecific whole antibodies may be made by knobs-into-holes engineering (J. B. B. Ridgeway et al., Protein Eng., 9, 616-621, 1996).

Bispecific diabodies, as opposed to bispecific whole antibodies, may also be particularly useful because they can be readily constructed and expressed in E. coli. Diabodies (and many other polypeptides such as antibody fragments) of appropriate binding specificities can be readily selected using phage display (WO94/13804) from libraries. If one arm of the diabody is to be kept constant, for instance, with a specificity directed against antigen X, then a library can be made where the other arm is varied and an antibody of appropriate specificity selected.

In certain embodiments, the antibodies described herein may be provided in the form of a UniBody®. A UniBody® is an IgG4 antibody with the hinge region removed (see GenMab Utrecht, The Netherlands; see also, e.g., US20090226421). This proprietary antibody technology creates a stable, smaller antibody format with an anticipated longer therapeutic window than current small antibody formats. IgG4 antibodies are considered inert and thus do not interact with the immune system. Fully human IgG4 antibodies may be modified by eliminating the hinge region of the antibody to obtain half-molecule fragments having distinct stability properties relative to the corresponding intact IgG4 (GenMab, Utrecht). Halving the IgG4 molecule leaves only one area on the UniBody® that can bind to cognate antigens (e.g., disease targets) and the UniBody® therefore binds univalently to only one site on target cells. For certain cancer cell surface antigens, this univalent binding may not stimulate the cancer cells to grow as may be seen using bivalent antibodies having the same antigen specificity, and hence UniBody® technology may afford treatment options for some types of cancer that may be refractory to treatment with conventional antibodies. The small size of the UniBody® can be a great benefit when treating some forms of cancer, allowing for better distribution of the molecule over larger solid tumors and potentially increasing efficacy.

In certain embodiments, the antibodies of the present disclosure may take the form of a Nanobody®. Nanobodies® are encoded by single genes and are efficiently produced in almost all prokaryotic and eukaryotic hosts e.g. E. coli (see e.g. U.S. Pat. No. 6,765,087), molds (for example Aspergillus or Trichodermd) and yeast (for example Saccharomyces, Kluyvermyces, Hansenula or Pichia (see e.g. U.S. Pat. No. 6,838,254). The production process is scalable and multi-kilogram quantities of Nanobodies® have been produced. Nanobodies may be formulated as a ready -to-use solution having a long shelf life. The Nanoclone® method (see, e.g., WO 06/079372) is a proprietary method for generating Nanobodies against a desired target, based on automated high-throughput selection of B-cells.

In certain embodiments, the antibodies or antigen-binding fragments thereof are humanized. These embodiments refer to a chimeric molecule, generally prepared using recombinant techniques, having an antigen-binding site derived from an immunoglobulin from a non-human species and the remaining immunoglobulin structure of the molecule based upon the structure and/or sequence of a human immunoglobulin. The antigen-binding site may comprise either complete variable domains fused onto constant domains or only the CDRs grafted onto appropriate framework regions in the variable domains. Epitope binding sites may be wild type or modified by one or more amino acid substitutions. This eliminates the constant region as an immunogen in human individuals, but the possibility of an immune response to the foreign variable region remains (LoBuglio et ak, PNAS USA 86:4220-4224, 1989; Queen et ak, PNAS USA. 86:10029-10033, 1988; Riechmann et ak, Nature. 332:323-327, 1988). Illustrative methods for humanization of antibodies include the methods described in U.S. Patent No. 7,462,697.

Another approach focuses not only on providing human-derived constant regions, but modifying the variable regions as well so as to reshape them as closely as possible to human form. It is known that the variable regions of both heavy and light chains contain three complementarity determining regions (CDRs) which vary in response to the epitopes in question and determine binding capability, flanked by four framework regions (FRs) which are relatively conserved in a given species and which putatively provide a scaffolding for the CDRs. When nonhuman antibodies are prepared with respect to a particular epitope, the variable regions can be “reshaped” or “humanized” by grafting CDRs derived from nonhuman antibody on the FRs present in the human antibody to be modified. Application of this approach to various antibodies has been reported by Sato et ak, Cancer Res. 53:851-856, 1993; Riechmann et ak, Nature 332:323-327, 1988; Verhoeyen et ak, Science 239:1534-1536, 1988; Kettleborough et ak, Protein Engineering. 4:773-3783, 1991; Maeda et ak, Human Antibodies Hybridoma 2:124-134, 1991; Gorman et ak, PNAS USA. 88:4181-4185, 1991; Tempest et ak, Bio/Technology 9:266-271, 1991; Co et ak, PNAS USA. 88:2869-2873, 1991; Carter et ak, PNAS USA. 89:4285-4289, 1992; and Co et ak, J Immunol. 148:1149-1154, 1992. In some embodiments, humanized antibodies preserve all CDR sequences (for example, a humanized mouse antibody which contains all six CDRs from the mouse antibodies). In other embodiments, humanized antibodies have one or more CDRs (one, two, three, four, five, six) which are altered with respect to the original antibody, which are also termed one or more CDRs “derived from” one or more CDRs from the original antibody.

In certain embodiments, the antibodies are “chimeric” antibodies. In this regard, a chimeric antibody is comprised of an antigen-binding fragment of an antibody operably linked or otherwise fused to a heterologous Fc portion of a different antibody. In certain embodiments, the Fc domain or heterologous Fc domain is of human origin. In certain embodiments, the Fc domain or heterologous Fc domain is of mouse origin. In other embodiments, the heterologous Fc domain may be from a different Ig class from the parent antibody, including IgA (including subclasses IgAl and IgA2), IgD, IgE, IgG (including subclasses IgGl, IgG2, IgG3, and IgG4), and IgM. In further embodiments, the heterologous Fc domain may be comprised of CH2 and CH3 domains from one or more of the different Ig classes. As noted above with regard to humanized antibodies, the antigen-binding fragment of a chimeric antibody may comprise only one or more of the CDRs of the antibodies described herein (e.g., 1, 2, 3, 4, 5, or 6 CDRs of the antibodies described herein), or may comprise an entire variable domain (VL, VH or both).

As used herein, a subject “at risk” of developing a disease, or adverse reaction may or may not have detectable disease, or symptoms of disease, and may or may not have displayed detectable disease or symptoms of disease prior to the treatment methods described herein. “At risk” denotes that a subject has one or more risk factors, which are measurable parameters that correlate with development of a disease, as described herein and known in the art. A subject having one or more of these risk factors has a higher probability of developing disease, or an adverse reaction than a subject without one or more of these risk factor(s).

“Biocompatible” refers to materials or compounds which are generally not injurious to biological functions of a cell or subject and which will not result in any degree of unacceptable toxicity, including allergenic and disease states.

The term “binding” refers to a direct association between two molecules, due to, for example, covalent, electrostatic, hydrophobic, and ionic and/or hydrogen-bond interactions, including interactions such as salt bridges and water bridges.

By “coding sequence” is meant any nucleic acid sequence that contributes to the code for the polypeptide product of a gene. By contrast, the term “non-coding sequence” refers to any nucleic acid sequence that does not directly contribute to the code for the polypeptide product of a gene.

Throughout this disclosure, unless the context requires otherwise, the words “comprise,” “comprises,” and “comprising” will be understood to imply the inclusion of a stated step or element or group of steps or elements but not the exclusion of any other step or element or group of steps or elements.

By “consisting of’ is meant including, and limited to, whatever follows the phrase “consisting of.” Thus, the phrase “consisting of’ indicates that the listed elements are required or mandatory, and that no other elements may be present. By “consisting essentially of’ is meant including any elements listed after the phrase, and limited to other elements that do not interfere with or contribute to the activity or action specified in the disclosure for the listed elements. Thus, the phrase “consisting essentially of’ indicates that the listed elements are required or mandatory, but that other elements are optional and may or may not be present depending upon whether or not they materially affect the activity or action of the listed elements.

The term “endotoxin free” or “substantially endotoxin free” relates generally to compositions, solvents, and/or vessels that contain at most trace amounts ( e.g amounts having no clinically adverse physiological effects to a subject) of endotoxin, and preferably undetectable amounts of endotoxin. Endotoxins are toxins associated with certain micro-organisms, such as bacteria, typically gramnegative bacteria, although endotoxins may be found in gram-positive bacteria, such as Listeria monocytogenes. The most prevalent endotoxins are lipopolysaccharides (LPS) or lipo-oligo- saccharides (LOS) found in the outer membrane of various Gram-negative bacteria, and which represent a central pathogenic feature in the ability of these bacteria to cause disease. Small amounts of endotoxin in humans may produce fever, a lowering of the blood pressure, and activation of inflammation and coagulation, among other adverse physiological effects.

Therefore, in pharmaceutical production, it is often desirable to remove most or all traces of endotoxin from drug products and/or drug containers, because even small amounts may cause adverse effects in humans. A depyrogenation oven may be used for this purpose, as temperatures in excess of 300°C are typically required to break down most endotoxins. For instance, based on primary packaging material such as syringes or vials, the combination of a glass temperature of 250°C and a holding time of 30 minutes is often sufficient to achieve a 3 log reduction in endotoxin levels. Other methods of removing endotoxins are contemplated, including, for example, chromatography and filtration methods, as described herein and known in the art.

Endotoxins can be detected using routine techniques known in the art. For example, the Limulus Amoebocyte Lysate assay, which utilizes blood from the horseshoe crab, is a very sensitive assay for detecting presence of endotoxin. In this test, very low levels of LPS can cause detectable coagulation of the limulus lysate due a powerful enzymatic cascade that amplifies this reaction. Endotoxins can also be quantitated by enzyme-linked immunosorbent assay (ELISA). To be substantially endotoxin free, endotoxin levels may be less than about 0.001, 0.005, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.08, 0.09, 0.1, 0.5, 1.0, 1.5, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, or 10 EU/mg of active compound. Typically, 1 ng lipopoly saccharide (LPS) corresponds to about 1-10 EU.

The term “half maximal effective concentration” or “EC50” refers to the concentration of an agent (e.g., antibody) as described herein at which it induces a response halfway between the baseline and maximum after some specified exposure time; the EC50 of a graded dose response curve therefore represents the concentration of a compound at which 50% of its maximal effect is observed. EC50 also represents the plasma concentration required for obtaining 50% of a maximum effect in vivo. Similarly, the “EC90” refers to the concentration of an agent or composition at which 90% of its maximal effect is observed. The “EC90” can be calculated from the “EC50” and the Hill slope, or it can be determined from the data directly, using routine knowledge in the art. In some embodiments, the EC50 of an agent (e.g., antibody) is less than about 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 40, 50, 60, 70, 80, 90, 100, 200 or 500 nM. In some embodiments, an agent will have an EC5O value of about 1 nM or less.

“Immune response” means any immunological response originating from immune system, including responses from the cellular and humeral, innate and adaptive immune systems. Exemplary cellular immune cells include for example, lymphocytes, macrophages, T cells, B cells, NK cells, neutrophils, eosinophils, dendritic cells, mast cells, monocytes, and all subsets thereof. Cellular responses include for example, effector function, cytokine release, phagocytosis, efferocytosis, translocation, trafficking, proliferation, differentiation, activation, repression, cell-cell interactions, apoptosis, etc. Humeral responses include for example IgG, IgM, IgA, IgE, responses and their corresponding effector functions.

The “half-life” of an agent such as an antibody can refer to the time it takes for the agent to lose half of its pharmacologic, physiologic, or other activity, relative to such activity at the time of administration into the serum or tissue of an organism, or relative to any other defined time-point. “Half-life” can also refer to the time it takes for the amount or concentration of an agent to be reduced by half of a starting amount administered into the serum or tissue of an organism, relative to such amount or concentration at the time of administration into the serum or tissue of an organism, or relative to any other defined time-point. The half-life can be measured in serum and/or any one or more selected tissues.

The terms “modulating” and “altering” include “increasing,” “enhancing” or “stimulating,” as well as “decreasing” or “reducing,” typically in a statistically significant or a physiologically significant amount or degree relative to a control. An “increased,” “stimulated” or “enhanced” amount is typically a “statistically significant” amount, and may include an increase that is 1.1, 1.2, 1.5, 2, 3,

4, 5, 6, 7, 8, 9, 10, 15, 20, 30, 40, 50, 60, 70, 80, 90, 100 or more times (e.g., 500, 1000 times) (including all integers and ranges in between e.g., 1.5, 1.6, 1.7. 1.8, etc.) the amount produced by no composition (e.g., the absence of agent) or a control composition. A “decreased” or “reduced” amount is typically a “statistically significant” amount, and may include a 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% , 19%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, or 100% decrease (including all integers and ranges in between) in the amount produced by no composition (e.g., the absence of an agent) or a control composition. Examples of comparisons and “statistically significant” amounts are described herein.

The terms “polypeptide,” “protein” and “peptide” are used interchangeably and mean a polymer of amino acids not limited to any particular length. The term “enzyme” includes polypeptide or protein catalysts. The terms include modifications such as myristoylation, sulfation, glycosylation, phosphorylation and addition or deletion of signal sequences. The terms “polypeptide” or “protein” means one or more chains of amino acids, wherein each chain comprises amino acids covalently linked by peptide bonds, and wherein said polypeptide or protein can comprise a plurality of chains non-covalently and/or covalently linked together by peptide bonds, having the sequence of native proteins, that is, proteins produced by naturally -occurring and specifically non-recombinant cells, or genetically-engineered or recombinant cells, and comprise molecules having the amino acid sequence of the native protein, or molecules having deletions from, additions to, and/or substitutions of one or more amino acids of the native sequence. In certain embodiments, the polypeptide is a “recombinant” polypeptide, produced by recombinant cell that comprises one or more recombinant DNA molecules, which are typically made of heterologous polynucleotide sequences or combinations of polynucleotide sequences that would not otherwise be found in the cell.

The term “polynucleotide” and “nucleic acid” includes mRNA, RNA, cRNA, cDNA, and DNA. The term typically refers to polymeric form of nucleotides of at least 10 bases in length, either ribonucleotides or deoxynucleotides or a modified form of either type of nucleotide. The term includes single and double stranded forms of DNA. The terms “isolated DNA” and “isolated polynucleotide” and “isolated nucleic acid” refer to a molecule that has been isolated free of total genomic DNA of a particular species. Therefore, an isolated DNA segment encoding a polypeptide refers to a DNA segment that contains one or more coding sequences yet is substantially isolated away from, or purified free from, total genomic DNA of the species from which the DNA segment is obtained. Also included are non-coding polynucleotides ( e.g primers, probes, oligonucleotides), which do not encode a polypeptide. Also included are recombinant vectors, including, for example, expression vectors, viral vectors, plasmids, cosmids, phagemids, phage, viruses, and the like.

Additional coding or non-coding sequences may, but need not, be present within a polynucleotide described herein, and a polynucleotide may, but need not, be linked to other molecules and/or support materials. Hence, a polynucleotide or expressible polynucleotides, regardless of the length of the coding sequence itself, may be combined with other sequences, for example, expression control sequences.

The term “isolated” polypeptide or protein referred to herein means that a subject protein (1) is free of at least some other proteins with which it would typically be found in nature, (2) is essentially free of other proteins from the same source, e.g., from the same species, (3) is expressed by a cell from a different species, (4) has been separated from at least about 50 percent of polynucleotides, lipids, carbohydrates, or other materials with which it is associated in nature, (5) is not associated (by covalent or non-covalent interaction) with portions of a protein with which the “isolated protein” is associated in nature, (6) is operably associated (by covalent or non-covalent interaction) with a polypeptide with which it is not associated in nature, or (7) does not occur in nature. Such an isolated protein can be encoded by genomic DNA, cDNA, mRNA or other RNA, of may be of synthetic origin, or any combination thereof. In certain embodiments, the isolated protein is substantially free from proteins or polypeptides or other contaminants that are found in its natural environment that would interfere with its use (therapeutic, diagnostic, prophylactic, research or otherwise).

In certain embodiments, the “purity” of any given agent (e.g., antibody) in a composition may be defined. For instance, certain compositions may comprise an agent that is at least 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% pure on a protein basis or a weight- weight basis, including all decimals and ranges in between, as measured, for example and by no means limiting, by high performance liquid chromatography (HPLC), a well-known form of column chromatography used frequently in biochemistry and analytical chemistry to separate, identify, and quantify compounds.

The term “reference sequence” refers generally to a nucleic acid coding sequence, or amino acid sequence, to which another sequence is being compared. All polypeptide and polynucleotide sequences described herein are included as references sequences, including those described by name and those described in the Tables and the Sequence Listing.

Certain embodiments include biologically active “variants” and “fragments” of the proteins/polypeptides described herein, and the polynucleotides that encode the same. “Variants” contain one or more substitutions, additions, deletions, and/or insertions relative to a reference polypeptide or polynucleotide (see, e.g., the Tables and the Sequence Listing). A variant polypeptide or polynucleotide comprises an amino acid or nucleotide sequence with at least about 50%, 55%,

60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98% , 99% or more sequence identity or similarity or homology to a reference sequence, as described herein, and substantially retains the activity of that reference sequence. Also included are sequences that consist of or differ from a reference sequences by the addition, deletion, insertion, or substitution of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 30, 40, 50, 60,70, 80, 90, 100, 110, 120, 130, 140, 150 or more amino acids or nucleotides and which substantially retain at least one activity of that reference sequence. In certain embodiments, the additions or deletions include C-terminal and/or N- terminal additions and/or deletions.

The terms “sequence identity” or, for example, comprising a “sequence 50% identical to,” as used herein, refer to the extent that sequences are identical on a nucleotide-by -nucleotide basis or an amino acid-by-amino acid basis over a window of comparison. Thus, a “percentage of sequence identity” may be calculated by comparing two optimally aligned sequences over the window of comparison, determining the number of positions at which the identical nucleic acid base (e.g., A, T, C, G, I) or the identical amino acid residue (e.g., Ala, Pro, Ser, Thr, Gly, Val, Leu, lie, Phe, Tyr, Trp, Lys, Arg, His, Asp, Glu, Asn, Gin, Cys and Met) occurs in both sequences to yield the number of matched positions, dividing the number of matched positions by the total number of positions in the window of comparison (i.e., the window size), and multiplying the result by 100 to yield the percentage of sequence identity. Optimal alignment of sequences for aligning a comparison window may be conducted by computerized implementations of algorithms (GAP, BESTFIT, FAST A, and TFASTA in the Wisconsin Genetics Software Package Release 7.0, Genetics Computer Group, 575 Science Drive Madison, Wis., USA) or by inspection and the best alignment (i.e., resulting in the highest percentage homology over the comparison window) generated by any of the various methods selected. Reference also may be made to the BEAST family of programs as for example disclosed by Altschul et al., Nucl. Acids Res. 25:3389, 1997.

The term “solubility” refers to the property of an agent (e.g., antibody) provided herein to dissolve in a liquid solvent and form a homogeneous solution. Solubility is typically expressed as a concentration, either by mass of solute per unit volume of solvent (g of solute per kg of solvent, g per dE (100 mL), mg/ml, etc.), molarity, molality, mole fraction or other similar descriptions of concentration. The maximum equilibrium amount of solute that can dissolve per amount of solvent is the solubility of that solute in that solvent under the specified conditions, including temperature, pressure, pH, and the nature of the solvent. In certain embodiments, solubility is measured at physiological pH, or other pH, for example, at pH 5.0, pH 6.0, pH 7.0, pH 7.4, pH 7.6, pH 7.8, or pH 8.0 (e.g., about pH 5-8). In certain embodiments, solubility is measured in water or a physiological buffer such as PBS or NaCl (with or without NaP0 ₄ ). In specific embodiments, solubility is measured at relatively lower pH (e.g., pH 6.0) and relatively higher salt (e.g., 500mM NaCl and lOmM NaP0 ₄ ). In certain embodiments, solubility is measured in a biological fluid (solvent) such as blood or serum. In certain embodiments, the temperature can be about room temperature (e.g., about 20, 21, 22, 23,

24, 25°C) or about body temperature (37°C). In certain embodiments, an agent has a solubility of at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,

17, 18, 19, 20, 25, 30, 40, 50, 60, 70, 80, 90 or 100 mg/ml at room temperature or at 37°C.

A “subject” or a “subject in need thereof’ or a “patient” or a “patient in need thereof’ includes a mammalian subject such as a human subject.

“Substantially” or “essentially” means nearly totally or completely, for instance, 95%, 96%, 97%, 98%, 99% or greater of some given quantity.

By “statistically significant,” it is meant that the result was unlikely to have occurred by chance. Statistical significance can be determined by any method known in the art. Commonly used measures of significance include the p-value, which is the frequency or probability with which the observed event would occur, if the null hypothesis were true. If the obtained p-value is smaller than the significance level, then the null hypothesis is rejected. In simple cases, the significance level is defined at a p-value of 0.05 or less.

“Therapeutic response” refers to improvement of symptoms (whether or not sustained) based on administration of one or more therapeutic agents.

As used herein, the terms “therapeutically effective amount”, “therapeutic dose,” “prophylactically effective amount,” or “diagnostically effective amount” is the amount of an agent (e.g., antibody) needed to elicit the desired biological response following administration. As used herein, “treatment” of a subject (e.g., a mammal, such as a human) or a cell is any type of intervention used in an attempt to alter the natural course of the individual or cell. Treatment includes, but is not limited to, administration of a pharmaceutical composition, and may be performed either prophylactically or subsequent to the initiation of a pathologic event or contact with an etiologic agent. Also included are “prophylactic” treatments, which can be directed to reducing the rate of progression of the disease or condition being treated, delaying the onset of that disease or condition, or reducing the severity of its onset. “Treatment” or “prophylaxis” does not necessarily indicate complete eradication, cure, or prevention of the disease or condition, or associated symptoms thereof.

The term “wild-type” refers to a gene or gene product (e.g., a polypeptide) that is most frequently observed in a population and is thus arbitrarily designed the “normal” or “wild-type” form of the gene.

Each embodiment in this specification is to be applied to every other embodiment unless expressly stated otherwise.

Antibodies and Antigen-Binding Fragments Thereof

Certain embodiments include an isolated antibody, or antigen-binding fragment thereof, which specifically binds to a human fibroblast activation protein-a (FAPa or FAP). Certain antibodies, or antigen-binding fragments thereof, are “dual action” antibodies, which have dual binding specificity for human FAP and a human B7H3 protein at the same or substantially the same “paratope”, as described herein. For example, in some instances, a single fragment antigen binding (Fab) region is capable of binding to either human FAP or human B7H3 (see Figure 1), but typically not both simultaneously. In some instances, two separate but linked Fab regions, for example, as part of a whole antibody, are capable of simultaneously binding to human FAP and human B7H3 (see Figure 2). In some instances, a dual-action” antibody, or antigen-binding fragment thereof, specifically binds to human FAP and human B7H3 at the same or substantially the same paratope with comparable binding affinities, for example, wherein the binding affinities for FAP and B7H3 are about, within about, or less than about 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, or 50-fold relative to each other.

In certain embodiments, an antibody, or antigen-binding fragment thereof, is characterized by or comprises a heavy chain variable (V _H ) region that comprises complementary determining region V _H CDRI, V _H CDR2, and V _H CDR3 regions, and a light chain variable region (V _L ) region that comprises complementary determining V _L CDR1, V _L CDR2, and V _L CDR3 regions. The sequences of exemplary V _H CDRI, V _H CDR2, V _H CDR3, V _L CDR1, V _L CDR2, and V _L CDR3 regions are provided in

Thus, in certain embodiments, an antibody, or antigen-binding fragment thereof, comprises a heavy chain variable (V _H ) region comprising V _H CDR1, V _H CDR2, and V _H CDR3 regions selected from Table Al; and a light chain variable (V _L ) region comprising V _L CDR1, V _L CDR2, and V _L CDR3 regions selected from Table Al.

In particular embodiments, the CDR regions are as follows: the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 1-3; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 4-6; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 7-9; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 10-12; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 13-15; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 16-18; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 19-21; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 22-24; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 25-27; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 28-30; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 31-33; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 34-36; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 37-39; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 40-42; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 43-45; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 46-48; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 49-51; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 52-54; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 55-57; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 58-60; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 61-63; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 64-66; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 67-69; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 70-72; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 73-75; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 76-78; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 79-81; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 82-84; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 85-87; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 88-90; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 91-93; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 94-96; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 97-99; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 100-102; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 103- 105; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 106-108; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 109- 111; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 112-114; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 115- 117; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 118-120; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 121- 123; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 124-126; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 127- 129; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 130-132; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: S S; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 136-138; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 139- 141; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 142-144; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 145- 147; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 148-150; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: OI OS; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 04-06; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 157- 09; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 160-162; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 163- 165; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 166-168; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 169- 171; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 172-174; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 175- 177; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 178-180; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 181- 183; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 184-186; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 187- 189; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 190-192; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 193-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 196-198; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 199-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 202-204; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 205-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 208-210; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 211-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 214-216; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 217-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 220-222; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 223-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 226-228; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 229-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 232-234; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 235-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 238-240; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 241-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 244-246; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 247-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 250-252; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 253-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 256-258; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 259-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 262-264; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 265-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 268-270; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 271-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 274-276; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 277-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 280-282; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 283-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 286-288; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 289-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 292-294; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 295-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 298-300; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 301-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 304-306; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 307-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 310-312; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 313-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 316-318; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 319-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 322-324; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 325-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 328-330; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 331-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 334-336; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 337-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 340-342; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 343-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 346-348; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 349-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 352-354; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 355-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 358-360; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 361-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 364-366; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 367-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 370-372; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 373-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 376-378; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 379-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 382-384; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 385-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 388-390; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 391-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 394-396; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 397-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 400-402; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 403-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 406-408; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 409-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 412-414; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 415-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 418-420; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 421-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 424-426; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 427-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 430-432; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 433-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 436-438; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 439-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 442-444; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 445-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 448-450; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 451-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 454-456; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 457-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 460-462; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 463-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 466-468; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 469-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 472-474; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 475-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 478-480; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 481-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 484-486; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 487-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 490-492; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 493-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 496-498; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 499-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 502-504; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 505-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 508-510; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 511-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 514-516; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 517-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 520-522; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 523-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 526-528; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 529-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 532-534; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 535-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 538-540; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 541-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 544-546; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 547-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 550-552; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 553-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 556-558; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 559-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 562-564; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 565-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 568-570; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 571-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 574-576; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 577-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 580-582; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 583-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 586-588; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 589-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 592-594; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 595-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 598-600; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 601-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 604-606; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 607-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 610-612; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 613-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 616-618; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 619-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 622-624; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 625-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 628-630; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 631 -; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 634-636; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 637-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 640-642; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 643-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 646-648; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 649-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 652-654; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 655-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 658-660; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 661 -; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 664-666; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 667 -; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 670-672; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 673-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 676-678; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 679-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 682-684; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 685-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 688-690; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 691-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 694-696; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 697-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 700-702; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 703-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 706-708; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 709-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 712-714; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 715-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 718-720; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 721-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 724-726; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 727-; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 730-732; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 733- 735; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 736-738; the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 739- 741; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 742-744; or the V _H CDRI, a V _H CDR2, and V _H CDR3 regions respectively comprise SEQ ID NOs: 745- 747; and the V _L CDRI, V _L CDR2, and V _L CDR3 regions respectively comprise SEQ ID NOs: 748-750.

Also included are variants thereof, including affinity matured variants, which bind to FAP and optionally B7H3 at the same or substantially the same paratope, for example, variants having 1, 2, 3,

4, 5, 6, 7, or 8 total alterations across the CDR regions, for example, one or more the V _H CDRI, V _H CDR2, V _H CDR3, V _L CDRI, V _L CDR2, and/or V _L CDR3 sequences described herein. Exemplary “alterations” include amino acid substitutions, additions, and deletions.

In certain embodiments, an antibody, or antigen-binding fragment thereof, is characterized by or comprises a heavy chain (VH region, Fc region) and a light chain (or VL region). Exemplary sequences of heavy chain and light chains are provided in Table A2 below (V _H CDRI, V _H CDR2, V _H CDR3, V _L CDRI, V _L CDR2, and V _L CDR3 regions are in bold).

Thus, in certain embodiments, an antibody, or antigen-binding fragment thereof, specifically binds to human FAP and optionally human B7H3 at the same or substantially the same paratope, and comprises a heavy chain and a corresponding light chain selected from Table A2. For example, in some embodiments, the heavy chain is at least 80, 85, 90, 95, 97, 98, 99, or 100% identical to a sequence selected from Table A2, including wherein the heavy chain has about 1, 2, 3, 4, 5, or 6 alterations in the framework regions. In some embodiments, the light chain is at least 80, 85, 90, 95, 97, 98, 99, or 100% identical to a sequence selected from Table A2, including wherein the light chain has 1, 2, 3, 4, 5, or 6 alterations in the framework regions.

In some embodiments, the heavy chain and light chain sequences of an antibody or antigen binding fragment are as follows: the heavy chain comprises a sequence at least 80, 85, 90, 95, 97, 98, 99, or 100% identical to SEQ ID NO: 751, 753, 755, 757, 759, 761, 763, 765, 767, 769, 771, 773, 775, 777, 779, 781, 783,

785, 787, 789, 791, 793, 795, 797, 799, 801, 803, 805, 807, 809, 811, 813, 815, 817, 819, 821, 823,

825, 827, 829, 831, 833, 835, 837, 839, 841, 843, 845, 847, 849, 851, 853, 855, 857, 859, 861, 863,

865, 867, 869, 871, 873, 875, 877, 879, 881, 883, 885, 887, 889, 891, 893, 895, 897, 899, 901, 903,

905, 907, 909, 911, 913, 915, 917, 919, 921, 923, 925, 927, 929, 931, 933, 935, 937, 939, 941, 943,

945, 947, 949, 951, 953, 955, 957, 959, 961, 963, 965, 967, 969, 971, 973, 975, 977, 979, 981, 983,

985, 987, 989, 991, 993, 995, 997, 999, 1001, 1003, or 1005; and the light chain respectively comprises a sequence at least 80, 85, 90, 95, 97, 98, 99, or 100% identical to SEQ ID NO: 752, 754, 756, 758, 760, 762, 764, 766, 768, 770, 772, 774, 776, 778, 780, 782, 784, 786, 788, 790, 792, 794, 796, 798, 800, 802, 804, 806, 808, 810, 812, 814, 816, 818,

820, 822, 824, 826, 828, 830, 832, 834, 836, 838, 840, 842, 844, 846, 848, 850, 852, 854, 856, 858,

860, 862, 864, 866, 868, 870, 872, 874, 876, 878, 880, 882, 884, 886, 888, 890, 892, 894, 896, 898,

900, 902, 904, 906, 908, 910, 912, 914, 916, 918, 920, 922, 924, 926, 928, 930, 932, 934, 936, 938,

940, 942, 944, 946, 948, 950, 952, 954, 956, 958, 960, 962, 964, 966, 968, 970, 972, 974, 976, 978,

980, 982, 984, 986, 988, 990, 992, 994, 996, 998, 1000, 1002, 1004, or 1006.

Also included are variants thereof, for example, variants having 1, 2, 3, 4, 5, or 6 alterations in one or more framework regions. Exemplary “alterations” include amino acid substitutions, additions, and deletions.

In certain embodiments, variant antibodies or antigen-binding fragments, or V _H , VL, or CDR regions thereof, specifically bind to FAP and/or B7H3 at least about 50%, at least about 70%, and in certain embodiments, at least about 90% as well as an antibody sequence specifically set forth herein. In further embodiments, such variant antibodies or antigen-binding fragments, or V _H , VL, or CDR regions thereof, bind to FAP and/or B7H3 with greater affinity than the antibodies described herein, for example, that bind quantitatively at least about 105%, 106%, 107%, 108%, 109%, or 110% as well as an antibody sequence specifically set forth herein.

Determination of the three-dimensional structures of representative polypeptides (e.g., variant antibody or an antigen-binding fragment thereof) may be made through routine methodologies such that substitution, addition, deletion or insertion of one or more amino acids with selected natural or non-natural amino acids can be virtually modeled for purposes of determining whether a so derived structural variant retains the space-filling properties of presently disclosed species. See, for instance, Donate et al., 1994 Prot. Sci. 3:2378; Bradley et al., Science 309: 1868-1871 (2005); Schueler- Furman et al., Science 310:638 (2005); Dietz et al., Proc. Nat. Acad. Sci. USA 103:1244 (2006); Dodson et al., Nature 450: 176 (2007); Qian et al., Nature 450:259 (2007); Raman et al. Science 327:1014-1018 (2010). Some additional non-limiting examples of computer algorithms that may be used for these and related embodiments, such as for rational design of antibodies, and antigen-binding domains thereof, as provided herein, include VMD which is a molecular visualization program for displaying, animating, and analyzing large biomolecular systems using 3-D graphics and built-in scripting (see the website for the Theoretical and Computational Biophysics Group, University of Illinois at Urbana-Champagne, at ks.uiuc.edu/Research/vmd/. Many other computer programs are known in the art and available to the skilled person and which allow for determining atomic dimensions from space-filling models (van der Waals radii) of energy-minimized conformations; GRID, which seeks to determine regions of high affinity for different chemical groups, thereby enhancing binding, Monte Carlo searches, which calculate mathematical alignment, and CHARMM (Brooks et al. (1983) J. Comput. Chem. 4:187-217) and AMBER (Weiner et al (1981) J. Comput. Chem. 106: 765), which assess force field calculations, and analysis (see also, Eisenfield et al. (1991) Am. J. Physiol. 261:C376-386; Lybrand (1991) J. Pharm. Belg. 46:49-54; Froimowitz (1990) Biotechniques 8:640-644; Burbam et al. (1990) Proteins 7:99-111; Pedersen (1985) Environ. Health Perspect. 61:185-190; and Kini et al. (1991) J. Biomol. Struct. Dyn. 9:475-488). A variety of appropriate computational computer programs are also commercially available, such as from Schrodinger (Munich, Germany).

In some embodiments, as noted above, an antibody, or an antigen-binding fragment thereof, specifically binds to human FAP, for example, cell surface-expressed human FAP. Fibroblast activation protein-a, also known as prolyl endopeptidase FAP, is a 170 kDa type II transmembrane glycoprotein. It contains a short cytoplasmic N terminal part (6 amino acids), a transmembrane region (amino acids 7-25), and an extracellular region with an alpha/beta-hydrolase domain and an eight- bladed beta-propeller domain. FAP expression under physiological conditions is very low in the majority of adult tissues. However, FAP expression is high in reactive stromal fibroblasts of epithelial cancers, granulation tissue of healing wounds, and malignant cells of bone and soft tissue sarcomas. FAP is also involved in the control of fibroblast growth or epithelial-mesenchymal interactions during development, tissue repair, and epithelial carcinogenesis. FAP expression is seen on activated stromal fibroblasts of more than 90% of all human carcinomas, and stromal fibroblasts play an important role in the development, growth and metastasis of carcinomas.

In particular embodiments, the FAP is human FAP, or a peptide epitope thereof. Exemplary human FAP sequences are provided in Table T1 below.

In certain embodiments, an antibody, or an antigen-binding fragment thereof, specifically binds to a human FAP from Table Tl, for example, an extracellular region of human FAP. In specific embodiments, an antibody, or antigen-binding fragment thereof, binds to human FAP with a K _D of about 0.4 or 0.5 nM (400 or 500 pM) or lower.

In certain embodiments, an antibody, or antigen-binding fragment thereof, specifically binds to human FAP with a binding affinity of about 10 pM to about 500 pM or to about 1 nM, or about, at least about, or no more than about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150,

160, 170, 180, 190, 200, 300, 400, 500, 600, 700, 800, 900 pM, or 1 nM, or optionally with an affinity that ranges from about 10 pM to about 500 pM, about 10 pM to about 400 pM, about 10 pM to about 300 pM, about 10 pM to about 200 pM, about 10 pM to about 100 pM, about 10 pM to about 50 pM, or about 20 pM to about 500 pM, about 20 pM to about 400 pM, about 20 pM to about 300 pM, about 20 pM to about 200 pM, about 20 pM to about 100 pM, about 20 pM to about 50 pM, or about 30 pM to about 500 pM, about 30 pM to about 400 pM, about 30 pM to about 300 pM, about 30 pM to about 200 pM, about 30 pM to about 100 pM, about 30 pM to about 50 pM, or about 20 pM to about 200 pM, about 30 pM to about 300 pM, about 40 pM to about 400 pM, about 50 pM to about 500 pM, about 60 pM to about 600 pM, about 70 pM to about 700 pM, about 80 pM to about 800 pM, about 90 pM to about 900 pM, or about 100 pM to about 1 nM.

In some embodiments, as noted above, an antibody, or an antigen-binding fragment thereof, has dual binding specificity, and specifically binds to human FAP and B7H3 at the same or substantially the same paratope. CD276 (B7H3) is an immune checkpoint molecule that participates in the regulation of T-cell-mediated immune responses, and is expressed on some solid tumours. It plays a protective role in tumor cells, for example, by inhibiting natural-killer mediated cell lysis and potentially other anti-tumor immune responses.

In particular embodiments, the B7H3 is human B7H3, or a peptide epitope thereof. Exemplary human B7H3 sequences are provided in Table T2 below.

In certain embodiments, an antibody, or an antigen-binding fragment thereof, specifically binds to a human B7H3 protein, for example, selected from Table T2, including a domain of human B7H3 selected from one or more of the Ig-like V-type 1 domain, Ig-like C2-type 1 domain, Ig-like V- type 2 domain, and an Ig-like C2-type 2 domain. In specific embodiments, an antibody, or antigenbinding fragment thereof, binds to human BH73 with a K _D of about 0.4 or 0.5 nM (400 or 500 pM) or lower.

In certain embodiments, an antibody, or antigen-binding fragment thereof, specifically binds to human B7H3 with a binding affinity of about 10 pM to about 500 pM or to about 1 nM, or about, at least about, or no more than about 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150,

160, 170, 180, 190, 200, 300, 400, 500, 600, 700, 800, 900 pM, or 1 nM, or optionally with an affinity that ranges from about 10 pM to about 500 pM, about 10 pM to about 400 pM, about 10 pM to about 300 pM, about 10 pM to about 200 pM, about 10 pM to about 100 pM, about 10 pM to about 50 pM, or about 20 pM to about 500 pM, about 20 pM to about 400 pM, about 20 pM to about 300 pM, about 20 pM to about 200 pM, about 20 pM to about 100 pM, about 20 pM to about 50 pM, or about 30 pM to about 500 pM, about 30 pM to about 400 pM, about 30 pM to about 300 pM, about 30 pM to about 200 pM, about 30 pM to about 100 pM, about 30 pM to about 50 pM, or about 20 pM to about 200 pM, about 30 pM to about 300 pM, about 40 pM to about 400 pM, about 50 pM to about 500 pM, about 60 pM to about 600 pM, about 70 pM to about 700 pM, about 80 pM to about 800 pM, about 90 pM to about 900 pM, or about 100 pM to about 1 nM.

In some embodiments, an antibody, or antigen-binding fragment thereof, has a binding affinity (Kd or EC50) for each of (i) human FAP and (ii) human B7H3, wherein the affinity for (i) and (ii) is about, within about, or less than about 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 40, or 50-fold relative to each other, or within the range of about 20 pM to about 200 pM, about 30 pM to about 300 pM, about 40 pM to about 400 pM, about 50 pM to about 500 pM, about 60 pM to about 600 pM, about 70 pM to about 700 pM, about 80 pM to about 800 pM, about 90 pM to about 900 pM, about 100 pM to about 1 nM. Merely for illustrative purposes, the binding interactions between an antibody, or antigen binding fragment thereof, and FAP and/or B7H3 can be detected and quantified using a variety of routine methods, including biacore assays (for example, with appropriately tagged soluble reagents, bound to a sensor chip), FACS analyses with cells expressing FAP and/or B7H3 on the cell surface (either native, or recombinant), immunoassays, fluorescence staining assays, ELISA assays, and microcalorimetry approaches such as ITC (Isothermal Titration Calorimetry).

Certain embodiments include bispecific multispecific antibodies, or antigen-binding fragments thereof. For example, some bispecific or multispecific antibodies, or antibody -binding fragments thereof, comprise a first Fab region that specifically binds to human FAP and human B7H3 at the same or substantially the same epitope, as described herein, and a second Fab region that specifically binds to an additional antigen, for example, a cell surface antigen/receptor expressed on an immune cell or cancer cell. Examples of such additional antigens include CD3, human Her2/neu, Herl/EGF receptor (EGFR), EGFR1, EGFR2, EGFR3, Her3, A33 antigen, B7H3, B7H4, CD3, CD4, CD5, CD8, CD 16, CD19, CD20, CD30, CD22, CD23 (IgE Receptor), B-cell maturation antigen (BCMA), Trop-2, Claudin 6, claudin 16, MAGE-3, C242 antigen, 5T4, IL-6, IL-13, PD-1, CTLA-4, PD-L1, TIGIT, TIM-3, LAG-3, 4-1BB, vascular endothelial growth factor VEGF (e.g., VEGF-A) VEGFR-1, VEGFR-2, CD27, CD28, CD33, CD37, CD40, CD44, CD51, CD52, CD56, CD74, CD80, CD86, CD137, CD152, CD200, CD221, CCR4, HLA-DR, CTLA-4, NPC-1C, Siglecl5, MIC-A, NKG2A, NKG2D, Nkp30, NKp46, tenascin, vimentin, insulin-like growth factor 1 receptor (IGF- 1R), alpha-fetoprotein, insulin-like growth factor 1 (IGF-1), carbonic anhydrase 9 (CA-IX), carcinoembryonic antigen (CEA), guanylyl cyclase C, NY-ESO-1, p53, survivin, integrin anb3, integrin a5b1, folate receptor 1, transmembrane glycoprotein NMB, fibroblast activation protein alpha (FAP), glycoprotein 75, TAG-72, MUC1, MUC16 (or CA-125), phosphatidylserine, prostate-specific membrane antigen (PSMA), NR-LU-13 antigen, SLAM family member 7 (SLAMF7), EGP40 pancarcinoma antigen, B-cell activating factor (BAFF), platelet-derived growth factor receptor, glycoprotein EpCAM (17-1A), Programmed Death-1, protein disulfide isomerase (PDI), Phosphatase of Regenerating Liver 3 (PRL-3), prostatic acid phosphatase, Lewis-Y antigen, GD2 (a disialoganglioside expressed on tumors of neuroectodermal origin), glypican-3 (GPC3), and mesothelin.

In some embodiments, an antibody, or antigen-binding fragment thereof, comprises an Fc region, for example, an Fc region selected from an IgA Fc region (including subclasses IgAl and IgA2), an IgD Fc region, an IgE Fc region, an IgG Fc region (including subclasses IgGl, IgG2, IgG3, and IgG4), and an IgM Fc region. In some instances, the Fc region is a human Fc region. In some embodiments, an Fc region has high effector function in humans, for example, an IgGl Fc region or an IgG3 Fc region. In some embodiments, an Fc region has low effector function in humans, for example, an IgG2 Fc region or an IgG4 Fc region. The Fc region of an antibody interacts with a number of Fc receptors and ligands, imparting an array of important functional capabilities referred to as effector functions. For IgG, the Fc region comprises Ig domains CH2 and CH3 and the N-terminal hinge leading into CH2. One family of Fc receptors for the IgG class are the Fc gamma receptors (FcyRs). These receptors mediate communication between antibodies and the cellular arm of the immune system (Raghavan et al,

1996, Annu Rev Cell Dev Biol 12:181-220; Ravetch et al, 2001, Annu Rev Immunol 19:275-290). In humans this protein family includes FcyRI (CD64), including isoforms FcyRIa, FcyRIb, and FcyRIc; FcyRII (CD32), including isoforms FcyRIIa (including allotypes H131 and R131), FcyRIIb (including FcyRIIb-l and FcyRIIb-2), and FcyRIIc; and FcyRIII (CD16), including isoforms FcyRIIIa (including allotypes V158 and F158) and FcyRIIIb (including allotypes FcyRIIIb-NA 1 and FcyRIIIb-NA2) (Jefferis et al, 2002, Immunol Lett 82:57-65). These receptors typically have an extracellular domain that mediates binding to Fc, a membrane spanning region, and an intracellular domain that may mediate some signaling event within the cell. These receptors are expressed in a variety of immune cells including monocytes, macrophages, neutrophils, dendritic cells, eosinophils, mast cells, platelets, B cells, large granular lymphocytes, Langerhans’ cells, natural killer (NK) cells, and T cells. Formation of the Fc/FcyR complex recruits these effector cells to sites of bound antigen, typically resulting in signaling events within the cells and important subsequent immune responses such as release of inflammation mediators, B cell activation, endocytosis, phagocytosis, and cytotoxic attack.

The ability to mediate cytotoxic and phagocytic effector functions is a potential mechanism by which antibodies destroy targeted cells. The cell-mediated reaction wherein nonspecific cytotoxic cells that express FcyRs recognize bound antibody on a target cell and subsequently cause lysis of the target cell is referred to as antibody dependent cell-mediated cytotoxicity (ADCC) (Raghavan et al. , 1996, Annu Rev Cell Dev Biol 12:181-220; Ghetie et al, 2000, Annu Rev Immunol 18:739-766; Ravetch et al, 2001, Annu Rev Immunol 19:275-290). The cell-mediated reaction wherein nonspecific cytotoxic cells that express FcyRs recognize bound antibody on a target cell and subsequently cause phagocytosis of the target cell is referred to as antibody dependent cell-mediated phagocytosis (ADCP). All FcyRs bind the same region on Fc, at the N-terminal end of the Cg2 (CH2) domain and the preceding hinge. This interaction is well characterized structurally (Sondermann et al, 2001, J Mol Biol 309:737-749), and several structures of the human Fc bound to the extracellular domain of human FcyRIIIb have been solved (pdb accession code 1E4K) (Sondermann et al, 2000, Nature 406:267-273.) (pdb accession codes 1IIS and 1IIX) (Radaev et al, 2001, J Biol Chem 276:16469-16477.)

The Fc region is also involved in activation of the complement cascade. In the classical complement pathway, Cl binds with its Clq subunits to Fc fragments of IgG or IgM, which has formed a complex with antigen(s). In certain embodiments, modifications to the Fc region comprise modifications that alter (either enhance or decrease) the ability of an antibody, or antigen-binding fragment thereof, as described herein to activate the complement system (see e.g., U.S. Patent 7,740,847). To assess complement activation, a complement-dependent cytotoxicity (CDC) assay may be performed (See, e.g., Gazzano-Santoro et al, J. Immunol. Methods, 202:163 (1996)).

In some embodiments, an antibody, or antigen-binding fragment thereof, comprises a modified Fc region, including Fc regions having altered properties or biological activities relative to wild-type Fc region(s). In particular embodiments, a modified Fc region has at least one altered effector function and/or pharmacokinetic (PK) characteristic relative to a wild-type Fc region. Thus in certain embodiments, an antibody, or antigen-binding fragment thereof, has a modified Fc region with altered functional properties, such as reduced or enhanced CDC, ADCC, or ADCP activity, reduced or enhanced binding affinity for a specific FcyR, or increased serum half-life.

Examples of modified Fc regions include those having mutated sequences, for instance, by substitution, insertion, deletion, or truncation of one or more amino acids relative to a wild-type sequence, hybrid Fc polypeptides composed of domains from different immunoglobulin classes/subclasses, Fc polypeptides having altered glycosylation/sialylation patterns, and Fc polypeptides that are modified or derivatized, for example, by biotinylation (see, e.g., US Application No. 2010/0209424), phosphorylation, sulfation, etc., or any combination of the foregoing. Such modifications can be employed to alter (e.g., increase, decrease) the binding properties of the Fc region to one or more particular FcRs (e.g., FcyRI, FcyRIIa, FcyRIIb, FcyRIIc, FcyRIIIa, FcyRIIIb, FcRn), its pharmacokinetic properties (e.g., stability or half-life, bioavailability, tissue distribution, volume of distribution, concentration, elimination rate constant, elimination rate, area under the curve (AUC), clearance, Cmax, tmax, Cmin, fluctuation), its immunogenicity, its complement fixation or activation, and/or the CDC/ ADCC/ ADCP-related activities of the Fc region, among other properties described herein, relative to a corresponding wild-type Fc sequence of an antibody or antigen-binding fragment thereof. Included are modified Fc regions of human and/or mouse origin.

Certain embodiments include antibodies, or antigen-binding fragments thereof, which comprise hybrid Fc regions, for example, Fc regions that comprise a combination of Fc domains (e.g., hinge, CH2, CH3, CH4) from immunoglobulins of different species (e.g., human, mouse), different Ig classes, and/or different Ig subclasses. General examples include hybrid Fc regions that comprise, consist of, or consist essentially of the following combination of CH2/CH3 domains: IgAl/IgAl, IgAl/IgA2, IgAl/IgD, IgAl/IgE, IgAl/IgGl, IgAl/IgG2, IgAl/IgG3, IgAl/IgG4, IgAl/IgM, IgA2/IgAl, IgA2/IgA2, IgA2/IgD, IgA2/IgE, IgA2/IgGl, IgA2/IgG2, IgA2/IgG3, IgA2/IgG4, IgA2/IgM, IgD/IgAl, IgD/IgA2, IgD/IgD, IgD/IgE, IgD/IgGl, IgD/IgG2, IgD/IgG3, IgD/IgG4, IgD/IgM, IgE/IgAl, IgE/IgA2, IgE/IgD, IgE/IgE, IgE/IgGl, IgE/IgG2, IgE/IgG3, IgE/IgG4, IgE/IgM, IgGl/IgAl, IgGl/IgA2, IgGl/IgD, IgGl/IgE, IgGl/IgGl, IgGl/IgG2, IgGl/IgG3, IgGl/IgG4, IgGl/IgM, IgG2/IgAl, IgG2/IgA2, IgG2/IgD, IgG2/IgE, IgG2/IgGl, IgG2/IgG2, IgG2/IgG3, IgG2/IgG4, IgG2/IgM, IgG3/IgAl, IgG3/IgA2, IgG3/IgD, IgG3/IgE, IgG3/IgGl, IgG3/IgG2, IgG3/IgG3, IgG3/IgG4, IgG3/IgM, IgG4/IgAl, IgG4/IgA2, IgG4/IgD, IgG4/IgE, IgG4/IgGl, IgG4/IgG2, IgG4/IgG3, IgG4/IgG4, IgG4/IgM, IgM/IgAl, IgM/IgA2, IgM/IgD, IgM/IgE, IgM/IgGl, IgM/IgG2, IgM/IgG3, IgM/IgG4, IgM/IgM (or fragments or variants thereof), and optionally include a hinge from one or more of IgAl, IgA2, IgD, IgGl, IgG2, IgG3, or IgG4, and/or a CH4 domain from IgE and/or IgM. In specific embodiments, the hinge, CH2, CH3, and CH4 domains are from human Ig.

Additional examples include hybrid Fc regions that comprise, consist of, or consist essentially of the following combination of CH2/CH4 domains: IgAl/IgE, IgA2/IgE, IgD/IgE, IgE/IgE,

IgGl/IgE, IgG2/IgE, IgG3/IgE, IgG4/IgE, IgM/IgE, IgAl/IgM, IgA2/IgM, IgD/IgM, IgE/IgM, IgGl/IgM, IgG2/IgM, IgG3/IgM, IgG4/IgM, IgM/IgM (or fragments or variants thereof), and optionally include a hinge from one or more of IgAl, IgA2, IgD, IgGl, IgG2, IgG3, IgG4, and/or a CH3 domain from one or more of IgAl, IgA2, IgD, IgE, IgGl, IgG2, IgG3, IgG4, or IgM. In specific embodiments, the hinge, CH2, CH3, and CH4 domains are from human Ig.

Certain examples include hybrid Fc regions that comprise, consist of, or consist essentially of the following combination of CH3/CH4 domains: IgAl/IgE, IgA2/IgE, IgD/IgE, IgE/IgE, IgGl/IgE, IgG2/IgE, IgG3/IgE, IgG4/IgE, IgM/IgE, IgAl/IgM, IgA2/IgM, IgD/IgM, IgE/IgM, IgGl/IgM, IgG2/IgM, IgG3/IgM, IgG4/IgM, IgM/IgM (or fragments or variants thereof), and optionally include a hinge from one or more of IgAl, IgA2, IgD, IgGl, IgG2, IgG3, IgG4, and/or a CH2 domain from one or more of IgAl, IgA2, IgD, IgE, IgGl, IgG2, IgG3, IgG4, or IgM. In specific embodiments, the hinge, CH2, CH3, and CH4 domains are from human Ig.

Particular examples include hybrid Fc regions that comprise, consist of, or consist essentially of the following combination of hinge/CH2 domains: IgAl/IgAl, IgAl/IgA2, IgAl/IgD, IgAl/IgE, IgAl/IgGl, IgAl/IgG2, IgAl/IgG3, IgAl/IgG4, IgAl/IgM, IgA2/IgAl, IgA2/IgA2, IgA2/IgD, IgA2/IgE, IgA2/IgGl, IgA2/IgG2, IgA2/IgG3, IgA2/IgG4, IgA2/IgM, IgD/IgAl, IgD/IgA2, IgD/IgD, IgD/IgE, IgD/IgGl, IgD/IgG2, IgD/IgG3, IgD/IgG4, IgD/IgM, IgGl/IgAl, IgGl/IgA2, IgGl/IgD, IgGl/IgE, IgGl/IgGl, IgGl/IgG2, IgGl/IgG3, IgGl/IgG4, IgGl/IgM, IgG2/IgAl, IgG2/IgA2, IgG2/IgD, IgG2/IgE, IgG2/IgGl, IgG2/IgG2, IgG2/IgG3, IgG2/IgG4, IgG2/IgM, IgG3/IgAl, IgG3/IgA2, IgG3/IgD, IgG3/IgE, IgG3/IgGl, IgG3/IgG2, IgG3/IgG3, IgG3/IgG4, IgG3/IgM, IgG4/IgAl, IgG4/IgA2, IgG4/IgD, IgG4/IgE, IgG4/IgGl, IgG4/IgG2, IgG4/IgG3, IgG4/IgG4, IgG4/IgM (or fragments or variants thereof), and optionally include a CH3 domain from one or more of IgAl, IgA2, IgD, IgE, IgGl, IgG2, IgG3, IgG4, or IgM, and/or a CH4 domain from IgE and/or IgM. In specific embodiments, the hinge, CH2, CH3, and CH4 domains are from human Ig.

Certain examples include hybrid Fc regions that comprise, consist of, or consist essentially of the following combination of hinge/CH3 domains: IgAl/IgAl, IgAl/IgA2, IgAl/IgD, IgAl/IgE, IgAl/IgGl, IgAl/IgG2, IgAl/IgG3, IgAl/IgG4, IgAl/IgM, IgA2/IgAl, IgA2/IgA2, IgA2/IgD, IgA2/IgE, IgA2/IgGl, IgA2/IgG2, IgA2/IgG3, IgA2/IgG4, IgA2/IgM, IgD/IgAl, IgD/IgA2, IgD/IgD, IgD/IgE, IgD/IgGl, IgD/IgG2, IgD/IgG3, IgD/IgG4, IgD/IgM, IgGl/IgAl, IgGl/IgA2, IgGl/IgD, IgGl/IgE, IgGl/IgGl, IgGl/IgG2, IgGl/IgG3, IgGl/IgG4, IgGl/IgM, IgG2/IgAl, IgG2/IgA2, IgG2/IgD, IgG2/IgE, IgG2/IgGl, IgG2/IgG2, IgG2/IgG3, IgG2/IgG4, IgG2/IgM, IgG3/IgAl, IgG3/IgA2, IgG3/IgD, IgG3/IgE, IgG3/IgGl, IgG3/IgG2, IgG3/IgG3, IgG3/IgG4, IgG3/IgM, IgG4/IgAl, IgG4/IgA2, IgG4/IgD, IgG4/IgE, IgG4/IgGl, IgG4/IgG2, IgG4/IgG3, IgG4/IgG4, IgG4/IgM (or fragments or variants thereof), and optionally include a CH2 domain from one or more of IgAl, IgA2, IgD, IgE, IgGl, IgG2, IgG3, IgG4, or IgM, and/or a CH4 domain from IgE and/or IgM. In specific embodiments, the hinge, CH2, CH3, and CH4 domains are from human Ig.

Some examples include hybrid Fc regions that comprise, consist of, or consist essentially of the following combination of hinge/CH4 domains: IgAl/IgE, IgAl/IgM, IgA2/IgE, IgA2/IgM, IgD/IgE, IgD/IgM, IgGl/IgE, IgGl/IgM, IgG2/IgE, IgG2/IgM, IgG3/IgE, IgG3/IgM, IgG4/IgE, IgG4/IgM (or fragments or variants thereof), and optionally include a CH2 domain from one or more of IgAl, IgA2, IgD, IgE, IgGl, IgG2, IgG3, IgG4, or IgM, and/or a CH3 domain from one or more of IgAl, IgA2, IgD, IgE, IgGl, IgG2, IgG3, IgG4, or IgM.

Specific examples of hybrid Fc regions can be found, for example, in WO 2008/147143, which are derived from combinations of IgG subclasses or combinations of human IgD and IgG.

Also included are antibodies, or antigen-binding fragments thereof, which have derivatized or otherwise modified Fc regions. In certain aspects, the Fc region may be modified by phosphorylation, sulfation, acrylation, glycosylation, methylation, famesylation, acetylation, amidation, and the like, for instance, relative to a wild-type or naturally-occurring Fc region. In certain embodiments, the Fc region may comprise wild-type or native glycosylation patterns, or alternatively, it may comprise increased glycosylation relative to a native form, decreased glycosylation relative to a native form, or it may be entirely deglycosylated. As one example of a modified Fc glycoform, decreased glycosylation of an Fc region reduces binding to the Cl q region of the first complement component Cl, a decrease in ADCC-related activity, and/or a decrease in CDC-related activity. Certain embodiments thus employ a deglycosylated or aglycosylated Fc region. See, e.g., WO 2005/047337 for the production of exemplary aglycosylated Fc regions. Another example of an Fc region glycoform can be generated by substituting the Q295 position with a cysteine residue (see, e.g., U.S. Application No. 2010/0080794), according to the Kabat et al. numbering system. Certain embodiments may include Fc regions where about 80-100% of the glycoprotein in Fc region comprises a mature core carbohydrate structure that lacks fructose (see, e.g., U.S. Application No. 2010/0255013). Some embodiments may include Fc regions that are optimized by substitution or deletion to reduce the level of fucosylation, for instance, to increase affinity for FcyRI, FcyRIa, or FcyRIIIa, and/or to improve phagocytosis by FcyRIIa-expressing cells (see U.S. Application Nos. 2010/0249382 and 2007/0148170).

As another example of a modified Fc glycoform, an Fc region of an antibody or antigen binding fragment thereof may comprise oligomannose-type N-glycans, and optionally have one or more of the following: increased ADCC effector activity, increased binding affinity for FcyRIIIA (and certain other FcRs), and/or similar or lower binding affinity for mannose receptor, relative to a corresponding Fc region that contains complex-type N-glycans (see, e.g., U.S. Application No. 2007/0092521 and U.S. Patent No. 7,700,321). As another example, enhanced affinity of Fc regions for FcyRs has been achieved using engineered glycoforms generated by expression of antibodies in engineered or variant cell lines (see, e.g., Umana et al., Nat Biotechnol. 17:176-180, 1999; Davies et al., Biotechnol Bioeng. 74:288-294, 2001; Shields et al., J Biol Chem. 277:26733-26740, 2002; Shinkawa et al., 2003, J Biol Chem. 278:3466-3473, 2003; and U.S. Application No. 2007/0111281). Certain Fc region glycoforms comprise an increased proportion of N-gly coside bond type complex sugar chains, which do not have the 1 -position of fucose bound to the 6-position of N- acetylglucosamine at the reducing end of the sugar chain (see, e.g., U.S. Application No. 2010/0092997). Particular embodiments may include IgG Fc region that is glycosylated with at least one galactose moiety connected to a respective terminal sialic acid moiety by an a-2,6 linkage, optionally where the Fc region has a higher anti-inflammatory activity relative to a corresponding, wild-type Fc region (see U.S. Application No. 2008/0206246). Certain of these and related altered glycosylation approaches have generated substantial enhancements of the capacity of Fc regions to selectively bind FcRs such as FcyRIII, to mediate ADCC, and to alter other properties of Fc regions, as described herein.

Certain modified Fc regions of an antibody or antigen-binding fragment thereof may have altered binding to one or more FcRs, and/or corresponding changes to effector function, relative to a corresponding, wild-type Fc sequence (e.g., same species, same Ig class, same Ig subclass). For instance, such Fc regions may have increased binding to one or more of Fey receptors, Fca receptors, Fes receptors, and/or the neonatal Fc receptor, relative to a corresponding, wild-type Fc sequence. In other embodiments, variant, fragment, hybrid, or modified Fc regions may have decreased binding to one or more of Fey receptors, Fca receptors, Fes receptors, and/or the neonatal Fc receptor, relative to a corresponding, wild-type Fc sequence. Specific FcRs are described elsewhere herein.

In some embodiments, an antibody comprises an Fc domain, comprising one or more mutations to increase binding to one or more of Fey receptors, Fca receptors, Fes receptors, and/or the neonatal Fc receptor, relative to a corresponding, wild-type Fc sequence. In some embodiments, an antibody comprises an Fc domain, comprising one or more mutations to decrease binding to one or more of Fey receptors, Fca receptors, Fes receptors, and/or the neonatal Fc receptor, relative to a corresponding, wild-type Fc sequence.

Specific examples of Fc variants having altered (e.g., increased, decreased) effector function FcR binding can be found, for example, in U.S. Pat. Nos. 5,624,821 and 7,425,619; U.S. Application Nos. 2009/0017023, 2009/0010921, and 2010/0203046; and WO 2000/42072 and WO 2004/016750. Certain examples include human Fc regions having a one or more substitutions at position 298, 333, and/or 334, for example, S298A, E333A, and/or K334A (based on the numbering of the EU index of Rabat et al.), which have been shown to increase binding to the activating receptor FcyRIIIa and reduce binding to the inhibitory receptor FcyRIIb. These mutations can be combined to obtain double and triple mutation variants that have further improvements in binding to FcRs. Certain embodiments include a S298A/E333A/K334A triple mutant, which has increased binding to FcyRIIIa. decreased binding to FcyRIIb. and increased ADCC (see, e.g., Shields et al., J Biol Chem. 276:6591- 6604, 2001; and Presta et al., Biochem Soc Trans. 30:487-490, 2002). See also engineered Fc gly coforms that have increased binding to FcRs, as disclosed in Umana et al., supra; and U.S. Patent No. 7,662,925. Some embodiments include Fc regions that comprise one or more substitutions selected from 434S, 252Y/428F, 252Y/434S, and 428F/434S (see U.S. Application Nos. 2009/0163699 and 20060173170), based on the EU index of Kabat et al.

As noted above, certain modified Fc regions may have altered effector functions, relative to a corresponding, wild-type Fc sequence. For example, such Fc regions may have increased complement fixation or activation, increased Clq binding affinity, increased CDC-related activity, increased ADCC -related activity, and/or increased ADCP-related activity, relative to a corresponding, wild-type Fc sequence. In some embodiments, such Fc regions may have decreased complement fixation or activation, decreased Clq binding affinity, decreased CDC-related activity, decreased ADCC-related activity, and/or decreased ADCP-related activity, relative to a corresponding, wild-type Fc sequence. As merely one illustrative example, an Fc region may comprise a deletion or substitution in a complement-binding site, such as a Clq-binding site, and/or a deletion or substitution in an ADCC site. Examples of such deletions/substitutions are described, for example, in U.S. Patent No.

7,030,226. Many Fc effector functions, such as ADCC, can be assayed according to routine techniques in the art. (see, e.g., Zuckerman et al., CRC Crit Rev Microbiol. 7:1-26, 1978). Useful effector cells for such assays includes, but are not limited to, natural killer (NK) cells, macrophages, and other peripheral blood mononuclear cells (PBMC). Alternatively, or additionally, certain Fc effector functions may be assessed in vivo, for example, by employing an animal model described in Clynes et al. PNAS. 95:652-656, 1998.

Certain modified Fc regions have altered stability or half-life relative to a corresponding, wild-type Fc sequence. In certain embodiments, such Fc regions may have increased half-life relative to a corresponding, wild-type Fc sequence. In some embodiments, modified Fc regions have decreased half-life relative to a corresponding, wild-type Fc sequence. Half-life can be measured in vitro (e.g., under physiological conditions) or in vivo, according to routine techniques in the art, such as radiolabeling, EFISA, or other methods. In vivo measurements of stability or half-life can be measured in one or more bodily fluids, including blood, serum, plasma, urine, or cerebrospinal fluid, or a given tissue, such as the liver, kidneys, muscle, central nervous system tissues, bone, etc. As one example, modifications to an Fc region that alter its ability to bind the FcRn can alter its half-life in vivo. Assays for measuring the in vivo pharmacokinetic properties (e.g., in vivo mean elimination half-life) and non-limiting examples of Fc modifications that alter its binding to the FcRn are described, for example, in U.S. Pat. Nos. 7,217,797 and 7,732,570; and U.S. Application Nos. US 2010/0143254 and 2010/0143254. Additional non-limiting examples of modifications to alter stability or half-life include substitutions/deletions at one or more of amino acid residues selected from 251-256, 285-290, and 308-314 in the CH2 domain, and 385-389 and 428-436 in the CH3 domain, according to the numbering system of Kabat et al. See U.S. Application No. 2003/0190311. Specific examples include substitution with leucine at position 251, substitution with tyrosine, tryptophan or phenylalanine at position 252, substitution with threonine or serine at position 254, substitution with arginine at position 255, substitution with glutamine, arginine, serine, threonine, or glutamate at position 256, substitution with threonine at position 308, substitution with proline at position 309, substitution with serine at position 311, substitution with aspartate at position 312, substitution with leucine at position 314, substitution with arginine, aspartate or serine at position 385, substitution with threonine or proline at position 386, substitution with arginine or proline at position 387, substitution with proline, asparagine or serine at position 389, substitution with methionine or threonine at position 428, substitution with tyrosine or phenylalanine at position 434, substitution with histidine, arginine, lysine or serine at position 433, and/or substitution with histidine, tyrosine, arginine or threonine at position 436, including any combination thereof. Such modifications optionally increase affinity of the Fc region for the FcRn and thereby increase half-life, relative to a corresponding, wild-type Fc region.

Certain modified Fc regions have altered solubility relative to a corresponding, wild-type Fc sequence. In certain embodiments, such Fc regions have increased solubility relative to a corresponding, wild-type Fc sequence. In some embodiments, modified Fc regions have decreased solubility relative to a corresponding, wild-type Fc sequence. Solubility can be measured, for example, in vitro (e.g., under physiological conditions) according to routine techniques in the art. Exemplary solubility measurements are described elsewhere herein.

Additional examples of variants include IgG Fc regions having conservative or nonconservative substitutions (as described elsewhere herein) at one or more of positions 250, 314, or 428 of the heavy chain, or in any combination thereof, such as at positions 250 and 428, or at positions 250 and 314, or at positions 314 and 428, or at positions 250, 314, and 428 (see, e.g., U.S. Application No. 2011/0183412). In specific embodiments, the residue at position 250 is substituted with glutamic acid or glutamine, and/or the residue at position 428 is substituted with leucine or phenylalanine. As another illustrative example of an IgG Fc variant, any one or more of the amino acid residues at positions 214 to 238, 297 to 299, 318 to 322, and/or 327 to 331 may be used as a suitable target for modification (e.g., conservative or non-conservative substitution, deletion). In particular embodiments, the IgG Fc variant CH2 domain contains amino acid substitutions at positions 228, 234, 235, and/or 331 (e.g., human IgG4 with Ser228Pro and Leu235Ala mutations) to attenuate the effector functions of the Fc region (see U.S. Patent No. 7,030,226). Here, the numbering of the residues in the heavy chain is that of the EU index (see Kabat et al., “Sequences of Proteins of Immunological Interest,” 5th Ed., National Institutes of Health, Bethesda, Md. (1991)). Certain of these and related embodiments have altered (e.g., increased, decreased) FcRn binding and/or serum half-life, optionally without reduced effector functions such as ADCC or CDC-related activities.

Additional examples include variant Fc regions that comprise one or more amino acid substitutions at positions 279, 341, 343 or 373 of a wild-type Fc region, or any combination thereof (see, e.g., U.S. Application No. 2007/0224188). The wild-type amino acid residues at these positions for human IgG are valine (279), glycine (341), proline (343) and tyrosine (373). The substation(s) can be conservative or non-conservative, or can include non-naturally occurring amino acids or mimetics, as described herein. Alone or in combination with these substitutions, certain embodiments may also employ a variant Fc region that comprises at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more amino acid substitutions selected from the following: 235G, 235R, 236F, 236R, 236Y, 237K, 237N, 237R, 238E, 238 G, 238H, 2381, 238L, 238V, 238W, 238Y, 244L, 245R, 247A, 247D, 247E, 247F, 247M, 247N, 247Q, 247R, 247S, 247T, 247W, 247Y, 248F, 248P, 248Q, 248W, 249L, 249M, 249N, 249P, 249Y, 251H, 2511, 251W, 254D, 254E, 254F, 254G, 254H, 2541, 254K, 254L, 254M, 254N, 254P, 254Q, 254R, 254V, 254W, 254Y, 255K, 255N, 256H, 2561, 256K, 256L, 256V, 256W, 256Y, 257A, 2571, 257M, 257N, 257S, 258D, 260S, 262L, 264S, 265K, 265S, 267H, 2671, 267K, 268K, 269N, 269Q,

27 IT, 272H, 272K, 272L, 272R, 279 A, 279D, 279F, 279G, 279H, 2791, 279K, 279L, 279M, 279N, 279Q, 279R, 279S, 279T, 279W, 279Y, 280T, 283F, 283G, 283H, 2831, 283K, 283L, 283M, 283P, 283 R, 283T, 283W, 283Y, 285N, 286F, 288N, 288P, 292E, 292F, 292G, 2921, 292L, 293S, 293V, 301W, 304E, 307E, 307M, 312P, 315F, 315K, 315L, 315P, 315R, 316F, 316K, 317P, 317T, 318N, 318P, 318T, 332F, 332G, 332L, 332M, 332S, 332V, 332W, 339D, 339E, 339F, 339G, 339H, 3391, 339K, 339L, 339M, 339N, 339Q, 339R, 339S, 339W, 339Y, 341D, 341E, 341F, 341H, 3411, 341K, 341L, 341M, 341N, 341P, 341Q, 341R, 341S, 341T, 341V, 341W, 341Y, 343A, 343D, 343E, 343F, 343 G, 343H, 3431, 343K, 343L, 343M, 343N, 343Q, 343R, 343S, 343T, 343V, 343W, 343Y, 373D, 373E, 373F, 373G, 373H, 3731, 373K, 373L, 373M, 373N, 373Q, 373R, 373S, 373T, 373V, 373W, 375R, 376E, 376F, 376G, 376H, 3761, 376L, 376M, 376N, 376P, 376Q, 376R, 376S, 376T, 376V, 376W, 376Y, 377G, 377K, 377P, 378N, 379N, 379Q, 379S, 379T, 380D, 380N, 380S, 380T, 382D, 382F, 382H, 3821, 382K, 382L, 382M, 382N, 382P, 382Q, 382R, 382S, 382T, 382V, 382W, 382Y, 385E, 385P, 386K, 423N, 424H, 424M, 424V, 426D, 426L, 427N, 429 A, 429F, 429M, 430A, 430D, 43 OF, 430G, 430H, 4301, 430K, 430L, 430M, 430N, 430P, 430Q, 430R, 430S, 430T, 430V, 430W,

430Y, 431H, 43 IK, 43 IP, 432R, 432S, 438G, 438K, 438L, 438T, 438W, 439E, 439H, 439Q, 440D, 440E, 440F, 440G, 440H, 4401, 440K, 440L, 440M, 440Q, 440T, 440V or 442K. As above, the numbering of the residues in the heavy chain is that of the EU index (see Rabat et al., supra). Such variant Fc regions typically confer an altered effector function or altered serum half-life upon the antibody to which the variant Fc region is operably attached. Preferably the altered effector function is an increase in ADCC, a decrease in ADCC, an increase in CDC, a decrease in CDC, an increase in Clq binding affinity, a decrease in Clq binding affinity, an increase in FcR (preferably FcRn) binding affinity or a decrease in FcR (preferably FcRn) binding affinity as compared to a corresponding Fc region that lacks such amino acid substitution(s).

Additional examples include variant Fc regions that comprise an amino acid substitution at one or more of position(s) 221, 222, 224, 227, 228, 230, 231, 223, 233, 234, 235, 236, 237, 238, 239, 240, 241, 243, 244, 245, 246, 247, 249, 250, 258, 262, 263, 264, 265, 266, 267, 268, 269, 270, 271,

272, 273, 274, 275, 276, 278, 280, 281, 283, 285, 286, 288, 290, 291, 293, 294, 295, 296, 297, 298,

299, 300, 302, 313, 317, 318, 320, 322, 323, 324, 325, 326, 327, 328, 329, 330, 331, 332, 333, 334,

335 336 and/or 428 (see, e.g., U.S. Patent No. 7,662,925). In specific embodiments, the variant Fc region comprises at least one amino acid substitution selected from the group consisting of: P230A, E233D, L234E, L234Y, L234I, L235D, L235S, L235Y, L235I, S239D, S239E, S239N, S239Q, S239T, V240I, V240M, F243L, V264I, V264T, V264Y, V266I, E272Y, K274T, K274E, K274R, K274L, K274Y, F275W, N276L, Y278T, V302I, E318R, S324D, S324I, S324V, N325T, K326I, K326T, L328M, L328I, L328Q, L328D, L328V, L328T, A330Y, A330L, A330I, I332D, I332E, I332N, I332Q, T335D, T335R, and T335Y. In other specific embodiments, the variant Fc region comprises at least one amino acid substitution selected from the group consisting of: V264I, F243L/V264I, L328M, I332E, L328M/I332E, V264M332E, S298A I332E, S239E/I332E, S239Q/I332E, S239E, A330Y, I332D, L328I/I332E, L328Q/I332E, V264T, V240I, V266I, S239D, S239D/I332D, S239D/I332E, S239D/I332N, S239D/I332Q, S239E/I332D, S239E/I332N, S239E/I332Q, S239N/I332D, S239N/I332E, S239Q/I332D, A330Y/I332E, V264I/A330Y/I332E, A330L/I332E, V264I/A330L/I332E, L234E, L234Y, L234I, L235D, L235S, L235Y, L235I, S239T, V240M, V264Y, A330I, N325T, L328D/I332E, L328V/I332E, L328T/I332E, L328I/I332E, S239E/V264I/I332E, S239Q/V264M332E, S239E/V264I/A330Y/I332E, S239D/A330Y/I332E, S239N/A330Y/I332E, S239D/A330L/I332E, S239N/A330L/I332E, V264I/S298A/I332E, S239D/S298A I332E, S239N/S298A I332E, S239D/V264I/I332E, S239D/V264I/S298A I332E, S239D/V264I/A330L/I332E, S239D/I332E/A330I, P230A, P230A E233D/I332E, E272Y, K274T, K274E, K274R, K274L, K274Y, F275W, N276L, Y278T, V302I, E318R, S324D, S324I, S324V, K326I, K326T, T335D, T335R, T335Y, V240I/V266I, S239D/A330Y/I332E/L234I, S239D/A330Y/I332E/L235D, S239D/A330Y/I332E/V240I, S239D/A330Y/I332E/V264T, S239D/A330Y/I332E/K326E, and S239D/A330Y/I332E/K326T, In more specific embodiments, the variant Fc region comprises a series of substitutions selected from the group consisting of: N297D/I332E, F241Y/F243Y/V262T/V264T/N297D/I332E, S239D/N297D/I332E, S239E/N297D/I332E, S239D/D265Y/N297D/I332E, S239D/D265H/N297D/I332E, V264E/N297D/I332E, Y296N/N297D/I332E, N297D/A330Y/I332E, S239D/D265V/N297D/I332E, S239D/D265I/N297D/I332E, and N297D/S298A/A330Y/I332E. In specific embodiments, the variant Fc region comprises an amino acid substitution at position 332 (using the numbering of the EU index, Rabat et al., supra). Examples of substitutions include 332A, 332D, 332E, 332F, 332G, 332H, 332K, 332L, 332M, 332N, 332P, 332Q, 332R, 332S, 332T, 332V, 332W and 332Y. The numbering of the residues in the Fc region is that of the EU index of Kabat et al. Among other properties described herein, such variant Fc regions may have increased affinity for an FcyR. increased stability, and/or increased solubility, relative to a corresponding, wild-type Fc region.

Further examples include variant Fc regions that comprise one or more of the following amino acid substitutions: 224N/Y, 225 A, 228L, 230S, 239P, 240A, 241L, 243S/L/G/H/I, 244L, 246E, 247L/A, 252T, 254T/P, 258K, 261Y, 265V, 266A, 267G/N, 268N, 269K G, 273 A, 276D, 278H, 279M, 280N, 283G, 285R, 288R, 289A, 290E, 291L, 292Q, 297D, 299A, 300H, 301C, 304G, 305 A, 306I/F, 311R, 312N, 315D/K S, 320R, 322E, 323 A, 324T, 325S, 326E/R, 332T, 333D/G, 3351, 338R, 339T, 340Q, 341E, 342R, 344Q, 347R, 35 IS, 352A, 354A, 355W, 356G, 358T, 361D/Y, 362L,

364C, 365Q/P, 370R, 372L, 377V, 378T, 383N, 389S, 390D, 391C, 393 A, 394A, 399G, 404S, 408G, 409R, 4111, 412A, 414M, 421S, 4221, 426F/P, 428T, 430K, 431S, 432P, 433P, 438L, 439E/R, 440G, 44 IF, 442T, 445R, 446 A, 447E, optionally where the variant has altered recognition of an Fc ligand and/or altered effector function compared with a parent Fc polypeptide, and wherein the numbering of the residues is that of the EU index as in Kabat et al. Specific examples of these and related embodiments include variant Fc regions that comprise or consist of the following sets of substitutions:

(I) N276D, R292Q, V305A, I377V, T394A, V412A and K439E; (2) P244L, K246E, D399G and K409R; (3) S304G, K320R, S324T, K326E and M358T; (4) F243S, P247L, D265V, V266A, S383N and T411I; (5) H224N, F243L, T393A and H433P; (6) V240A, S267G, G341E and E356G; (7) M252T, P291L, P352A, R355W, N390D, S408G, S426F and A431S; (8) P228L, T289A, L365Q, N389S and 5440G; (9) F241L, V273A, K340Q and L441F; (10) F241L, T299A, I332T and M428T;

(II) E269K, Y300H, Q342R, V422I and G446A; (12) T225A, R301c, S304G, D312N, N315D,

L351S andN421S; (13) S254T, L306I, K326R and Q362L; (14) H224Y, P230S, V323A, E333D, K338R and S364C; (15) T335I, K414M and P445R; (16) T335I and K414M; (17) P247A, E258K, D280N, K288R, N297D, T299A, K322E, Q342R, S354A and L365P; (18) H268N, V279M, A339T, N361D and S426P; (19) C261Y, K290E, L306F, Q311R, E333G and Q438L; (20) E283G, N315K, E333G, R344Q, L365P and S442T; (21) Q347R, N361Y and K439R; (22) S239P, S254P, S267N, H285R, N315S, F372L, A378T, N390D, Y391C, F404S, E430K, L432P and K447E; and (23)

E269G, Y278H, N325S and K370R, wherein the numbering of the residues is that of the EU index as in Kabat et al. (see, e.g., U.S. Application No. 2010/0184959).

Variant Fc regions can also have one or more mutated hinge regions, as described, for example, in U.S. Application No. 2003/0118592. For instance, one or more cysteines in a hinge region can be deleted or substituted with a different amino acid. The mutated hinge region can comprise no cysteine residues, or it can comprise 1, 2, or 3 fewer cysteine residues than a corresponding, wild-type hinge region. In some embodiments, an Fc region having a mutated hinge region of this type exhibits a reduced ability to dimerize, relative to a wild-type Ig hinge region.

As noted above, antibodies having altered Fc regions typically have altered (e.g., improved, increased, decreased) pharmacokinetic properties relative to corresponding wild-type Fc region. Examples of pharmacokinetic properties include stability or half-life, bioavailability (the fraction of a drug that is absorbed), tissue distribution, volume of distribution (apparent volume in which a drug is distributed immediately after it has been injected intravenously and equilibrated between plasma and the surrounding tissues), concentration (initial or steady-state concentration of drug in plasma), elimination rate constant (rate at which drugs are removed from the body), elimination rate (rate of infusion required to balance elimination), area under the curve (AUC or exposure; integral of the concentration-time curve, after a single dose or in steady state), clearance (volume of plasma cleared of the drug per unit time), Cmax (peak plasma concentration of a drug after oral administration), tmax (time to reach Cmax), Cmin (lowest concentration that a drug reaches before the next dose is administered), and fluctuation (peak trough fluctuation within one dosing interval at steady state).

In particular embodiments, an antibody or antigen-binding fragment thereof has a biological half life at about pH 7.4, at about a physiological pH, at about 25°C or room temperature, and/or at about 37°C or human body temperature (e.g., in vivo, in serum, in a given tissue, in a given species such as rat, mouse, monkey, or human), of about or at least about 30 minutes, about 1 hour, about 2 hour, about 3 hours, about 4 hours, about 5 hours, about 6 hours, about 12 hours, about 18 hours, about 20 hours, about 24 hours, about 30 hours, about 36 hours, about 40 hours, about 48 hours, about 50 hours, about 60 hours, about 70 hours, about 72 hours, about 80 hours, about 84 hours, about 90 hours, about 96 hours, about 120 hours, or about 144 hours or more, or about 1 week, or about 2 weeks, or about 3 weeks, or about 4 weeks, or about 5 weeks, or about 6 weeks or more, or any intervening half-life, including all ranges in between.

In some embodiments, an antibody, or antigen-binding fragment thereof, has a Tm of about or at least about 60, 62, 64, 66, 68, 70, 72, 74, or 75°C. In some embodiments, an antibody, or antigen binding fragment, thereof has a Tm of about 60°C or greater.

Certain embodiments include fusion proteins and conjugates, comprising an antibody, or antigen-binding fragment thereof, as described herein. For example, certain embodiments relate to an antibody, or an antigen-binding fragment thereof, which is fused via an optional linker to a heterologous effector domain (see, for example, Figures 4A-4F). Examples of effector domains include immune cell-stimulatory ligands or domains, immune cell-inhibitory ligands or domains, and cytocidal (e.g., tumor cell cytocidal) ligands or domains. In specific embodiments, the heterologous effector domain is selected from one or more of interleukin-2 (IL-2), interleukin- 15 (IL-15), hybrid IL-2/IL-15, interleukin-7 (IL-7), interleukin- 10 (IL-10), interleukin-21 (L-12), a TNF superfamily ligand such as TRAIL, 4-1BBL, interleukin-21 (IL-21), an interferon (e.g., IFN-alpha, IFN-beta, IFN- gamma), CD40, GITR-L, OX40L, and CD70.

Certain fusion proteins include chimeric antigen receptors, or CARs, and cells comprising the same, including immune cells such as T-cells or dendritic cells. Thus, certain embodiments include a single-chain variable fragment (scFv) described herein, which has dual binding specificity for human FAP and B7H3, and which is fused via a spacer (or hinge) region to a transmembrane domain and an intracellular T-cell signaling domain, to form a CAR (see Figure 5). Certain embodiments include a chimeric antigen receptor (CAR) T cell, comprising the CAR.

A peptide linker/spacer sequence may also be employed to separate multiple polypeptide components by a distance sufficient to ensure that each polypeptide folds into its secondary and/or tertiary structures, if desired. Such a peptide linker sequence can be incorporated into a fusion polypeptide using standard techniques well known in the art.

Certain peptide spacer sequences may be chosen, for example, based on: (1) their ability to adopt a flexible extended conformation; (2) their inability to adopt a secondary structure that could interact with functional epitopes on the first and second polypeptides; and/or (3) the lack of hydrophobic or charged residues that might react with the polypeptide functional epitopes.

In one illustrative embodiment, peptide spacer sequences contain, for example, Gly, Asn, and Ser residues. Other near neutral amino acids, such as Thr and Ala, may also be included in the spacer sequence.

Other amino acid sequences which may be usefully employed as spacers include those disclosed in Maratea et ak, Gene 40:3946 (1985); Murphy et ak, Proc. Natl. Acad. Sci. USA 83:8258 8262 (1986); U.S. Pat. No. 4,935,233 and U.S. Pat. No. 4,751,180.

Other illustrative spacers may include, for example, Glu-Gly-Lys-Ser-Ser-Gly-Ser-Gly-Ser- Glu-Ser-Lys-Val-Asp (SEQ ID NO: 1014) (Chaudhary et ak, 1990, Proc. Natl. Acad. Sci. U.S.A.

87: 1066-1070) and Lys-Glu-Ser-Gly-Ser-Val-Ser-Ser-Glu-Gln-Leu-Ala-Gln-Phe-Arg- Ser-Leu-Asp (SEQ ID NO: 1015) (Bird et ak, 1988, Science 242:423-426).

In some embodiments, spacer sequences are not required when the first and second polypeptides have non-essential N-terminal amino acid regions that can be used to separate the functional domains and prevent steric interference. Two coding sequences can be fused directly without any spacer or by using a flexible polylinker composed, for example, of the pentamer Gly-Gly- Gly-Gly-Ser (SEQ ID NO: 1016) repeated 1 to 3 times. Such a spacer has been used in constructing single chain antibodies (scFv) by being inserted between VH and VL (Bird et ak, 1988, Science 242:423-426; Huston et ak, 1988, Proc. Natl. Acad. Sci. U.S.A. 85:5979-5883).

A peptide spacer, in certain embodiments, is designed to enable the correct interaction between two beta-sheets forming the variable region of the single chain antibody.

In certain illustrative embodiments, a peptide spacer is between 1 to 5 amino acids, between 5 to 10 amino acids, between 5 to 25 amino acids, between 5 to 50 amino acids, between 10 to 25 amino acids, between 10 to 50 amino acids, between 10 to 100 amino acids, or any intervening range of amino acids.

In other illustrative embodiments, a peptide spacer comprises about 1, 5, 10, 15, 20, 25, 30,

35, 40, 45, 50 or more amino acids in length.

Certain embodiments include an antibody, or an antigen-binding fragment thereof, which is conjugated or otherwise operably linked to an additional molecule, for example, a small molecule or proteinaceous toxin, a DNA or RNA molecule, a detectable label, a radioisotope, an aptamer, or an epitope tag. There are many linking groups known in the art for making antibody conjugates, including, for example, those disclosed in U.S. Pat. No. 5,208,020 or EP Patent 0 425 235 Bl, and Chari et al, Cancer Research 52: 127-131 (1992). The linking groups include disulfide groups, thioether groups, acid labile groups, photolabile groups, peptidase labile groups, and esterase labile groups, among others.

In some embodiments, an antibody, or antigen-binding fragment thereof, is conjugated or operably linked to a therapeutic compound. For instance, in some embodiments, an antibody, or antigen-binding fragment thereof, is conjugated to one or more cytotoxic or chemotherapeutic agents. General examples of cytotoxic or chemotherapeutic agents include, without limitation, alkylating agents, anti-metabolites, anthracyclines, anti-tumor antibiotics, platinums, type I topoisomerase inhibitors, type II topoisomerase inhibitors, vinca alkaloids, and taxanes.

In some embodiments, an antibody, or antigen-binding fragment thereof, is conjugated or operably linked to a radioisotope to form a radioconjugate. A variety of radioactive isotopes are available for the production of radioconjugate antibodies. Examples include, but are not limited to ⁹⁰ Y, ¹²³ I, ¹²⁵ I, ¹³¹ 1, ¹⁸⁶ Re, ¹⁸⁸ Re, ²¹¹ At, and ²¹² Bi. In some embodiments, an antibody, or antigen-binding fragment thereof, is conjugated or operably linked to a macrocyclic chelator useful for conjugating to radiometal ions. In certain embodiments, the macrocyclic chelator is 1,4,7,10-tetraazacyclododecane- N,N’,N”,N’”-tetraacetic acid (DOTA) which can be attached to the antibody via a linker molecule. Such linker molecules are commonly known in the art and described in Denardo et al., 1998, Clin Cancer Res. 4:2483-90; Peterson et al., 1999, Bioconjug. Chem. 10:553; and Zimmerman et al., 1999, Nucl. Med. Biol. 26:943-50.

In various embodiments, the antibodies described herein are conjugated to a detectable label that may be detected directly or indirectly. In “direct detection”, only one detectable antibody is used, i.e., a primary detectable antibody. Thus, direct detection means that the antibody that is conjugated to a detectable label may be detected, per se, without the need for the addition of a second antibody (secondary antibody).

A “detectable label” is a molecule or material that can produce a detectable (such as visually, electronically or otherwise) signal that indicates the presence and/or concentration of the label in a sample. When conjugated to an antibody, the detectable label can be used to locate and/or quantify the target to which the specific antibody is directed. Thereby, the presence and/or concentration of the target in a sample can be detected by detecting the signal produced by the detectable label. A detectable label can be detected directly or indirectly, and several different detectable labels conjugated to different specific-antibodies can be used in combination to detect one or more targets.

Examples of detectable labels, which may be detected directly, include fluorescent dyes and radioactive substances and metal particles. In contrast, indirect detection requires the application of one or more additional antibodies, i.e., secondary antibodies, after application of the primary antibody. Thus, the detection is performed by the detection of the binding of the secondary antibody or binding agent to the primary detectable antibody. Examples of primary detectable binding agents or antibodies requiring addition of a secondary binding agent or antibody include enzymatic detectable binding agents and hapten detectable binding agents or antibodies.

In some embodiments, the detectable label is conjugated to a nucleic acid polymer which comprises the first binding agent (e.g., in an ISH, WISH, or FISH process). In other embodiments, the detectable label is conjugated to an antibody which comprises the first binding agent (e.g., in an IHC process).

Examples of detectable labels include fluorescent labels, enzyme labels, radioisotopes, chemiluminescent labels, electrochemiluminescent labels, bioluminescent labels, polymers, polymer particles, metal particles, haptens, and dyes.

Examples of fluorescent labels include 5-(and 6)-carboxyfluorescein, 5- or 6- carboxyfluorescein, 6-(fluorescein)-5-(and 6)-carboxamido hexanoic acid, fluorescein isothiocyanate, rhodamine, tetramethylrhodamine, and dyes such as Cy2, Cy3, and Cy5, optionally substituted coumarin including AMCA, PerCP, phycobiliproteins including R-phycoerythrin (RPE) and allophycoerythrin (APC), Texas Red, Princeton Red, green fluorescent protein (GFP) and analogues thereof, and conjugates of R-phycoerythrin or allophycoerythrin, inorganic fluorescent labels such as particles based on semiconductor material like coated CdSe nanocrystallites.

Examples of polymer particle labels include micro particles or latex particles of polystyrene, PMMA or silica, which can be embedded with fluorescent dyes, or polymer micelles or capsules which contain dyes, enzymes or substrates.

Examples of metal particle labels include gold particles and coated gold particles, which can be converted by silver stains. Examples of haptens include DNP, fluorescein isothiocyanate (FITC), biotin, and digoxigenin. Examples of enzymatic labels include horseradish peroxidase (HRP), alkaline phosphatase (ALP or AP), b-galactosidase (GAL), glucose-6-phosphate dehydrogenase, b-N- acetylglucosamimidase, b-glucuronidase, invertase, Xanthine Oxidase, firefly luciferase and glucose oxidase (GO). Examples of commonly used substrates for horseradishperoxidase include 3,3’- diaminobenzidine (DAB), diaminobenzidine with nickel enhancement, 3-amino-9-ethylcarbazole (AEC), Benzidine dihydrochloride (BDHC), Hanker-Yates reagent (HYR), Indophane blue (IB), tetramethylbenzidine (TMB), 4-chloro-l-naphtol (CN), alpha-naphtol pyronin (.alpha. -NP), o- dianisidine (OD), 5-bromo-4-chloro-3-indolylphosp- hate (BCIP), Nitro blue tetrazolium (NBT), 2-(p- iodophenyl)-3-p-nitropheny- 1-5-phenyl tetrazolium chloride (INT), tetranitro blue tetrazolium (TNBT), 5-bromo-4-chloro-3-indoxyl-beta-D-galactoside/ferro-ferricya nide (BCIG/FF).

Examples of commonly used substrates for Alkaline Phosphatase include Naphthol-AS-B 1- phosphate/fast red TR (NABP/FR), Naphthol-AS-MX-phosphate/fast red TR (NAMP/FR), Naphthol- AS-B 1 -phosphate/- fast red TR (NABP/FR), Naphthol-AS-MX-phosphate/fast red TR (NAMP/FR), Naphthol-AS-Bl -phosphate/new fuschin (NABP/NF), bromochloroindolyl phosphate/nitroblue tetrazolium (BCIP/NBT), 5-Bromo-4-chloro-3-indolyl-b- d-galactopyranoside (BCIG).

Examples of luminescent labels include luminol, isoluminol, acridinium esters, 1,2-dioxetanes and pyridopyridazines. Examples of electrochemiluminescent labels include ruthenium derivatives. Examples of radioactive labels include radioactive isotopes of iodide, cobalt, selenium, tritium, carbon, sulfur and phosphorous.

The detectable labels or markers may be detected visually using, e.g., light microscopy, fluorescent microscopy, electron microscopy where the detectable substance is for example a dye, a colloidal gold particle, a luminescent reagent. Visually detectable substances bound to a biological marker may also be detected using a spectrophotometer. Where the detectable substance is a radioactive isotope detection can be visually by autoradiography, or non-visually using a scintillation counter. See, e.g., Larsson, 1988, Immunocytochemistry: Theory and Practice, (CRC Press, Boca Raton, Fla.); Methods in Molecular Biology, vol. 80 1998, John D. Pound (ed.) (Humana Press, Totowa, N.J.).

The desired functional properties of an antibody, or antigen-binding fragment thereof, may be assessed using a variety of methods known to the skilled person affinity /binding assays (for example, surface plasmon resonance, competitive inhibition assays); cytotoxicity assays, cell viability assays, cell proliferation or differentiation assays, cancer cell and/or tumor growth inhibition using in vitro or in vivo models. The antibodies described herein may also be tested for in vitro and in vivo efficacy. Such assays may be performed using well-established protocols known to the skilled person (see e.g., Current Protocols in Molecular Biology (Greene Publ. Assoc. Inc. & John Wiley & Sons, Inc., NY, NY); Current Protocols in Immunology (Edited by: John E. Coligan, Ada M. Kruisbeek, David H. Margulies, Ethan M. Shevach, Warren Strober 2001 John Wiley & Sons, NY, NY); or commercially available kits.

Methods of Use and Pharmaceutical Compositions

Certain embodiments include methods of treating, ameliorating the symptoms of, and/or reducing the progression of, a disease or condition in a subject in need thereof, comprising administering to the subject an antibody, or antigen-binding fragment thereof, as described herein

In some embodiments, the disease is a cancer, that is, the subject in need thereof has or is suspected of having a cancer. Certain embodiments thus include methods of treating, ameliorating the symptoms of, or inhibiting the progression of, a cancer in a subject in need thereof, comprising administering to the subject an antibody, or antigen-binding fragment thereof, as described herein, or a pharmaceutical or therapeutic composition comprising the same. Also included are methods of administering a fusion protein, or a bispecific or multispecific antibody, as described herein.

In some embodiments, the cancer associated with increased or aberrant expression of one or more proteins. For example, in some embodiments, the cancer is associated with increased or aberrant FAP expression, including wherein the subject has, or is selected for treatment based on having, the cancer associated with increased or aberrant FAP expression. In certain embodiments, the cancer is associated with increased or aberrant B7H3 expression, including wherein the subject has, or is selected for treatment based on having, a cancer associated with increased or aberrant B87H3 expression.

Certain embodiments include cell therapies that employ an antibody, or antigen-binding fragment thereof, as described herein. For example, certain embodiments include chimeric antigen receptor (CAR) T-cell therapies, which utilize T cells that have been genetically engineered to produce an artificial T cell receptor for use in immunotherapy. Certain embodiments thus include methods of administering a CAR T cell to a subject in need thereof, as described herein. In particular embodiments, a CAR T cell comprises a single-chain variable fragment (scFv), which specifically binds to FAP and optionally B7H3 at the same or substantially the same epitope, as described herein, and which is fused via a spacer (hinge) region to a transmembrane domain and an intracellular T-cell signaling domain, to form a CAR (see Figure 5). Certain embodiments include the steps of preparing the CAR T cell, for example, by obtaining a T cell from a subject in need thereof, engineering the T cell to comprise and express a polynucleotide that encodes the CAR, and administering the CAR T cell to the subject.

In some embodiments, administration of an antibody, or antigen-binding fragment thereof, or fusion protein or CAR T cell comprising the same, enhances an immune response to the cancer by about, or at least about, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000% or more, relative to a control. In some embodiments, any one or more of the effector domains or bispecific/multispecific Fab regions described herein can be used to further increase an immune response to the cancer.

In some embodiments, administration of an antibody, or antigen-binding fragment thereof, or fusion protein or CAR T cell comprising the same, increases cancer cell killing in the subject by about or at least about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000% or more relative to an untreated control. In some embodiments, any one or more of the effector domains or bispecific/multispecific Fab regions described herein can be used to further increase the cancer cell killing activity.

In some embodiments, administration of an antibody, or antigen-binding fragment thereof, or fusion protein or CAR T cell comprising the same, reduces invasiveness of the cancer by about or at least about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000% or more relative to an untreated control. In some embodiments, any one or more of the effector domains or bispecific/multispecific Fab regions described herein can be used to further reduce the invasiveness of the cancer.

In particular embodiments, the cancer is a primary cancer or a metastatic cancer. In specific embodiments, the cancer is selected from one or more of melanoma (optionally metastatic melanoma), kidney cancer (optionally renal cell carcinoma), pancreatic cancer, bone cancer, prostate cancer, small cell lung cancer, non-small cell lung cancer (NSCLC), mesothelioma, leukemia (optionally lymphocytic leukemia, chronic myelogenous leukemia, acute myeloid leukemia, or relapsed acute myeloid leukemia), multiple myeloma, lymphoma, hepatoma (hepatocellular carcinoma), sarcoma, B-cell malignancy, breast cancer, ovarian cancer, colorectal cancer, glioma, glioblastoma multiforme, meningioma, pituitary adenoma, vestibular schwannoma, primary CNS lymphoma, primitive neuroectodermal tumor (medulloblastoma), bladder cancer, uterine cancer, esophageal cancer, brain cancer, head and neck cancers, cervical cancer, testicular cancer, thyroid cancer, and stomach cancer.

In some embodiments, as noted above, the cancer is a metastatic cancer. Further to the above cancers, exemplary metastatic cancers include, without limitation, bladder cancers which have metastasized to the bone, liver, and/or lungs; breast cancers which have metastasized to the bone, brain, liver, and/or lungs; colorectal cancers which have metastasized to the liver, lungs, and/or peritoneum; kidney cancers which have metastasized to the adrenal glands, bone, brain, liver, and/or lungs; lung cancers which have metastasized to the adrenal glands, bone, brain, liver, and/or other lung sites; melanomas which have metastasized to the bone, brain, liver, lung, and/or skin/muscle; ovarian cancers which have metastasized to the liver, lung, and/or peritoneum; pancreatic cancers which have metastasized to the liver, lung, and/or peritoneum; prostate cancers which have metastasized to the adrenal glands, bone, liver, and/or lungs; stomach cancers which have metastasized to the liver, lung, and/or peritoneum; thyroid cancers which have metastasized to the bone, liver, and/or lungs; and uterine cancers which have metastasized to the bone, liver, lung, peritoneum, and/or vagina; among others.

In some embodiments, the antibodies, or antigen-binding fragments thereof, disclosed herein are used as part of adoptive immunotherapies, for example, autologous immunotherapies. Certain embodiments thus include methods of treating a cancer in a patient in need thereof, comprising:

(a) incubating ex v/Vo-derived immune cells an antibody, or antigen-binding fragment thereof, described herein; and

(b) administering the autologous immune cells to the patient.

In some instances, the ex v/Vo-derived immune cells are autologous cells, which are obtained from the patient to be treated. In some embodiments, the autologous immune cells comprise lymphocytes, natural killer (NK) cells, macrophages, and/or dendritic cells (DCs). In some embodiments, the lymphocytes comprise T-cells, optionally cytotoxic T-lymphocytes (CTLs). See, for example, June, J Clin Invest. 117: 1466-1476, 2007; Rosenberg and Restifo, Science. 348:62-68, 2015; Cooley et ak, Biol of Blood and Marrow Transplant. 13:33-42, 2007; and Li and Sim, Chin J Cancer Res. 30:173-196, 2018, for descriptions of adoptive T-cell and NK cell immunotherapies. In certain embodiments, the antibody, or antigen-binding fragment thereof, enhances the efficacy of the adoptively transferred immune cells. The methods for treating cancers can be combined with other therapeutic modalities. For example, a combination therapy described herein can be administered to a subject before, during, or after other therapeutic interventions, including symptomatic care, radiotherapy, surgery, transplantation hormone therapy, photodynamic therapy, antibiotic therapy, or any combination thereof. Symptomatic care includes administration of corticosteroids, to reduce cerebral edema, headaches, cognitive dysfunction, and emesis, and administration of anti-convulsants, to reduce seizures. Radiotherapy includes whole-brain irradiation, fractionated radiotherapy, and radiosurgery, such as stereotactic radiosurgery, which can be further combined with traditional surgery.

Certain embodiments thus include combination therapies for treating cancers, including methods of treating ameliorating the symptoms of, or inhibiting the progression of, a cancer in a subject in need thereof, comprising administering to the subject at least one antibody, or antigen binding fragment thereof, described herein in combination with at least one additional agent, for example, a cancer immunotherapy agent, a chemotherapeutic agent, a hormonal therapeutic agent, and/or a kinase inhibitor. In some embodiments, administering the at least one antibody, or antigen binding fragment thereof, enhances the susceptibility of the cancer to the additional agent by about or at least about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 2000% or more relative to the additional agent alone.

Certain combination therapies employ one or more cancer immunotherapy agents. In certain instances, an immunotherapy agent modulates the immune response of a subject, for example, to increase or maintain a cancer-related or cancer-specific immune response, and thereby results in increased immune cell inhibition or reduction of cancer cells. Exemplary immunotherapy agents include polypeptides, for example, antibodies and antigen-binding fragments thereof, ligands, and small peptides, and mixtures thereof. Also include as immunotherapy agents are small molecules, cells (e.g., immune cells such as T-cells), various cancer vaccines, gene therapy or other polynucleotide-based agents, including viral agents such as oncolytic viruses, and others known in the art. Thus, in certain embodiments, the cancer immunotherapy agent is selected from one or more of immune checkpoint modulatory agents, cancer vaccines, oncolytic viruses, cytokines, and a cell-based immunotherapies.

In certain embodiments, the cancer immunotherapy agent is an immune checkpoint modulatory agent. Particular examples include “antagonists” of one or more inhibitory immune checkpoint molecules, and “agonists” of one or more stimulatory immune checkpoint molecules. Generally, immune checkpoint molecules are components of the immune system that either turn up a signal (co-stimulatory molecules) or turn down a signal, the targeting of which has therapeutic potential in cancer because cancer cells can perturb the natural function of immune checkpoint molecules (see, e.g., Sharma and Allison, Science. 348:56-61, 2015; Topalian et ak, Cancer Cell. 27:450-461, 2015; Pardoll, Nature Reviews Cancer. 12:252-264, 2012). In some embodiments, the immune checkpoint modulatory agent (e.g., antagonist, agonist) “binds” or “specifically binds” to the one or more immune checkpoint molecules, as described herein.

In particular embodiments, the immune checkpoint modulatory agent is a polypeptide or peptide. The terms “peptide” and “polypeptide” are used interchangeably herein, however, in certain instances, the term “peptide” can refer to shorter polypeptides, for example, polypeptides that consist of about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, or 50 amino acids, including all integers and ranges (e.g., 5-10, 8-12, 10-15) in between. Polypeptides and peptides can be composed of naturally -occurring amino acids and/or non-naturally occurring amino acids, as described herein

Antibodies are also included as polypeptides. Thus, in some embodiments, the immune checkpoint modulatory polypeptide agent is an antibody or “antigen-binding fragment thereof’, as described elsewhere herein.

In some embodiments, the agent is or comprises a “ligand,” for example, a natural ligand, of the immune checkpoint molecule. A “ligand” refers generally to a substance or molecule that forms a complex with a target molecule (e.g., biomolecule) to serve a biological purpose, and includes a “protein ligand,” which generally produces a signal by binding to a site on a target molecule or target protein. Thus, certain agents are protein ligands that, in nature, bind to an immune checkpoint molecule and produce a signal. Also included are “modified ligands,” for example, protein ligands that are fused to a pharmacokinetic modifier, for example, an Fc region derived from an immunoglobulin.

The binding properties of polypeptides can be quantified using methods well known in the art (see Davies et ak, Annual Rev. Biochem. 59:439-473, 1990). In some embodiments, a polypeptide specifically binds to a target molecule, for example, an immune checkpoint molecule or an epitope thereof, with an equilibrium dissociation constant that is about or ranges from about <10-7 to about 10-8 M. In some embodiments, the equilibrium dissociation constant is about or ranges from about <10-9 M to about <10-10 M. In certain illustrative embodiments, the polypeptide has an affinity (Kd or EC50) for a target described herein (to which it specifically binds) of about, at least about, or less than about, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13,

14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 40, or 50 nM.

In some embodiments, the agent is a “small molecule,” which refers to an organic compound that is of synthetic or biological origin (biomolecule), but is typically not a polymer. Organic compounds refer to a large class of chemical compounds whose molecules contain carbon, typically excluding those that contain only carbonates, simple oxides of carbon, or cyanides. A “biomolecule” refers generally to an organic molecule that is produced by a living organism, including large polymeric molecules (biopolymers) such as peptides, polysaccharides, and nucleic acids as well, and small molecules such as primary secondary metabolites, lipids, phospholipids, glycolipids, sterols, glycerolipids, vitamins, and hormones. A “polymer” refers generally to a large molecule or macromolecule composed of repeating structural units, which are typically connected by covalent chemical bond.

In certain embodiments, a small molecule has a molecular weight of about or less than about 1000-2000 Daltons, typically between about 300 and 700 Daltons, and including about or less than about 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 500, 650, 600, 750, 700, 850, 800, 950, 1000 or 2000 Daltons.

Certain small molecules can have the “specific binding” characteristics described for herein polypeptides such as antibodies. For instance, in some embodiments a small molecule specifically binds to a target, for example, an immune checkpoint molecule, with a binding affinity (Kd or EC ₅ o) of about, at least about, or less than about, 0.01, 0.05, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3,

4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 40, or 50 nM.

In some embodiments, the immune checkpoint modulatory agent is an antagonist or inhibitor of one or more inhibitory immune checkpoint molecules. Exemplary inhibitory immune checkpoint molecules include Programmed Death-Ligand 1 (PD-L1), Programmed Death-Ligand 2 (PD-L2), Programmed Death 1 (PD-1), Cytotoxic T-Lymphocyte-Associated protein 4 (CTLA-4), Indoleamine 2,3 -dioxygenase (IDO), tryptophan 2,3-dioxygenase (TDO), T-cell Immunoglobulin domain and Mucin domain 3 (TIM-3), Lymphocyte Activation Gene-3 (LAG-3), V-domain Ig suppressor of T cell activation (VISTA), B and T Lymphocyte Attenuator (BTLA), CD 160, and T-cell immunoreceptor with Ig and ITIM domains (TIGIT).

In certain embodiments, the agent is a PD-1 (receptor) antagonist or inhibitor, the targeting of which has been shown to restore immune function in the tumor environment (see, e.g., Phillips et ak, Int. Immunol. 27:39-46, 2015). PD-1 is a cell surface receptor that belongs to the immunoglobulin superfamily and is expressed on T cells and pro-B cells. PD-1 interacts with two ligands, PD-L1 and PD-L2. PD-1 functions as an inhibitory immune checkpoint molecule, for example, by reducing or preventing the activation of T-cells, which in turn reduces autoimmunity and promotes self-tolerance. The inhibitory effect of PD-1 is accomplished at least in part through a dual mechanism of promoting apoptosis in antigen specific T-cells in lymph nodes while also reducing apoptosis in regulatory T cells (suppressor T cells). Some examples of PD-1 antagonists or inhibitors include an antibody or antigen-binding fragment or small molecule that specifically binds to PD-1 and reduces one or more of its immune-suppressive activities, for example, its downstream signaling or its interaction with PD- Ll. Specific examples of PD-1 antagonists or inhibitors include the antibodies nivolumab, pembrolizumab, PDR001, MK-3475, AMP-224, AMP-514, and pidilizumab, and antigen-binding fragments thereof (see, e.g., U.S. Patent Nos. 8,008,449; 8,993,731; 9,073,994; 9,084,776; 9,102,727; 9,102,728; 9,181,342; 9,217,034; 9,387,247; 9,492,539; 9,492,540; and U.S. Application Nos. 2012/0039906; 2015/0203579). In some embodiments, the agent is a PD-L1 antagonist or inhibitor. As noted above, PD-L1 is one of the natural ligands for the PD-1 receptor. General examples of PD-L1 antagonists or inhibitors include an antibody or antigen-binding fragment or small molecule that specifically binds to PD-L1 and reduces one or more of its immune-suppressive activities, for example, its binding to the PD-1 receptor. Specific examples of PD-L1 antagonists include the antibodies atezolizumab (MPDL3280A), avelumab (MSB0010718C), and durvalumab (MEDI4736), and antigen-binding fragments thereof (see, e.g., U.S. Patent Nos. 9,102,725; 9,393,301; 9,402,899; 9,439,962).

In some embodiments, the agent is a PD-L2 antagonist or inhibitor. As noted above, PD-L2 is one of the natural ligands for the PD-1 receptor. General examples of PD-L2 antagonists or inhibitors include an antibody or antigen-binding fragment or small molecule that specifically binds to PD-L2 and reduces one or more of its immune-suppressive activities, for example, its binding to the PD-1 receptor.

In some embodiments, the agent is a CTLA-4 antagonist or inhibitor. CTLA4 or CTLA-4 (cytotoxic T-lymphocyte-associated protein 4), also known as CD152 (cluster of differentiation 152), is a protein receptor that functions as an inhibitory immune checkpoint molecule, for example, by transmitting inhibitory signals to T-cells when it is bound to CD80 or CD86 on the surface of antigen- presenting cells. General examples CTLA-4 antagonists or inhibitors include an antibody or antigen binding fragment or small molecule that specifically binds to CTLA-4. Particular examples include the antibodies ipilimumab and tremelimumab, and antigen-binding fragments thereof. At least some of the activity of ipilimumab is believed to be mediated by antibody -dependent cell-mediated cytotoxicity (ADCC) killing of suppressor Tregs that express CTLA-4.

In some embodiments, the agent is an IDO antagonist or inhibitor, or a TDO antagonist or inhibitor. IDO and TDO are tryptophan catabolic enzymes with immune-inhibitory properties. Lor example, IDO is known to suppress T-cells and NK cells, generate and activate Tregs and myeloid- derived suppressor cells, and promote tumor angiogenesis. General examples of IDO and TDO antagonists or inhibitors include an antibody or antigen-binding fragment or small molecule that specifically binds to IDO or TDO (see, e.g., Platten et ak, front Immunol. 5: 673, 2014) and reduces or inhibits one or more immune-suppressive activities. Specific examples of IDO antagonists or inhibitors include indoximod (NLG-8189), 1 -methyl-tryptophan (1MT), b-Carboline (norharmane; 9H-pyrido[3,4-b]indole), rosmarinic acid, and epacadostat (see, e.g., Sheridan, Nature Biotechnology. 33:321-322, 2015). Specific examples of TDO antagonists or inhibitors include 680C91 and LM10 (see, e.g., Pilotte et ak, PNAS USA. 109:2497-2502, 2012).

In some embodiments, the agent is a TIM-3 antagonist or inhibitor. T-cell Immunoglobulin domain and Mucin domain 3 (TIM-3) is expressed on activated human CD4+ T-cells and regulates Thl and Thl7 cytokines. TIM-3 also acts as a negative regulator of Thl/Tcl function by triggering cell death upon interaction with its ligand, galectin-9. TIM-3 contributes to the suppressive tumor microenvironment and its overexpression is associated with poor prognosis in a variety of cancers (see, e.g., Li et al., Acta Oncol. 54:1706-13, 2015). General examples of TIM-3 antagonists or inhibitors include an antibody or antigen-binding fragment or small molecule that specifically binds to TIM-3 and reduces or inhibits one or more of its immune-suppressive activities.

In some embodiments, the agent is a LAG-3 antagonist or inhibitor. Lymphocyte Activation Gene-3 (LAG-3) is expressed on activated T-cells, natural killer cells, B-cells and plasmacytoid dendritic cells. It negatively regulates cellular proliferation, activation, and homeostasis of T-cells, in a similar fashion to CTLA-4 and PD-1 (see, e.g., Workman and Vignali. European Journal of Immun. 33: 970-9, 2003; and Workman et al., Journal of Immun. 172: 5450-5, 2004), and has been reported to play a role in Treg suppressive function (see, e.g., Huang et al., Immunity. 21: 503-13, 2004).

LAG3 also maintains CD8+ T-cells in a tolerogenic state and combines with PD-1 to maintain CD8 T-cell exhaustion. General examples of LAG-3 antagonists or inhibitors include an antibody or antigen-binding fragment or small molecule that specifically binds to LAG-3 and inhibits one or more of its immune-suppressive activities. Specific examples include the antibody BMS-986016, and antigen-binding fragments thereof.

In some embodiments, the agent is a VISTA antagonist or inhibitor. V-domain Ig suppressor of T cell activation (VISTA) is primarily expressed on hematopoietic cells and is an inhibitory immune checkpoint regulator that suppresses T-cell activation, induces Foxp3 expression, and is highly expressed within the tumor microenvironment where it suppresses anti-tumor T cell responses (see, e.g., Lines et al., Cancer Res. 74:1924-32, 2014). General examples of VISTA antagonists or inhibitors include an antibody or antigen-binding fragment or small molecule that specifically binds to VISTA and reduces one or more of its immune-suppressive activities.

In some embodiments, the agent is a BTLA antagonist or inhibitor. B- and T-lymphocyte attenuator (BTLA; CD272) expression is induced during activation of T-cells, and it inhibits T-cells via interaction with tumor necrosis family receptors (TNF-R) and B7 family of cell surface receptors. BTLA is a ligand for tumor necrosis factor (receptor) superfamily, member 14 (TNFRSF14), also known as herpes virus entry mediator (HVEM). BTLA-HVEM complexes negatively regulate T-cell immune responses, for example, by inhibiting the function of human CD8+ cancer-specific T-cells (see, e.g., Derre et al., J Clin Invest 120:157-67, 2009). General examples of BTLA antagonists or inhibitors include an antibody or antigen-binding fragment or small molecule that specifically binds to BTLA-4 and reduce one or more of its immune-suppressive activities.

In some embodiments, the agent is an HVEM antagonist or inhibitor, for example, an antagonist or inhibitor that specifically binds to HVEM and interferes with its interaction with BTLA or CD 160. General examples of HVEM antagonists or inhibitors include an antibody or antigen binding fragment or small molecule that specifically binds to HVEM, optionally reduces the HVEM/BTLA and/or HVEM/CD160 interaction, and thereby reduces one or more of the immune- suppressive activities of HVEM. In some embodiments, the agent is a CD 160 antagonist or inhibitor, for example, an antagonist or inhibitor that specifically binds to CD160 and interferes with its interaction with HVEM. General examples of CD 160 antagonists or inhibitors include an antibody or antigen-binding fragment or small molecule that specifically binds to CD 160, optionally reduces the CD160/HVEM interaction, and thereby reduces or inhibits one or more of its immune-suppressive activities.

In some embodiments, the agent is a TIGIT antagonist or inhibitor. T cell Ig and ITIM domain (TIGIT) is a co-inhibitory receptor that is found on the surface of a variety of lymphoid cells, and suppresses antitumor immunity, for example, via Tregs (Kurtulus et al., J Clin Invest. 125:4053- 4062, 2015). General examples of TIGIT antagonists or inhibitors include an antibody or antigenbinding fragment or small molecule that specifically binds to TIGIT and reduce one or more of its immune-suppressive activities (see, e.g., Johnston et al., Cancer Cell. 26:923-37, 2014).

In certain embodiments, the immune checkpoint modulatory agent is an agonist of one or more stimulatory immune checkpoint molecules. Exemplary stimulatory immune checkpoint molecules include 0X40, CD40, Glucocorticoid-Induced TNFR Family Related Gene (GITR),

CD 137 (4- IBB), CD27, CD28, CD226, and Herpes Virus Entry Mediator (HVEM).

In some embodiments, the agent is an 0X40 agonist. 0X40 (CD134) promotes the expansion of effector and memory T cells, and suppresses the differentiation and activity of T -regulatory cells (see, e.g., Croft et al., Immunol Rev. 229:173-91, 2009). Its ligand is OX40L (CD252). Since 0X40 signaling influences both T-cell activation and survival, it plays a key role in the initiation of an antitumor immune response in the lymph node and in the maintenance of the anti-tumor immune response in the tumor microenvironment. General examples of 0X40 agonists include an antibody or antigenbinding fragment or small molecule or ligand that specifically binds to 0X40 and increases one or more of its immunostimulatory activities. Specific examples include 0X86, OX-40L, Fc-OX40L, GSK3174998, MEDI0562 (a humanized 0X40 agonist), MEDI6469 (murine OX4 agonist), and MEDI6383 (an 0X40 agonist), and antigen-binding fragments thereof.

In some embodiments, the agent is a CD40 agonist. CD40 is expressed on antigen-presenting cells (APC) and some malignancies. Its ligand is CD40L (CD 154). On APC, ligation results in upregulation of costimulatory molecules, potentially bypassing the need for T-cell assistance in an antitumor immune response. CD40 agonist therapy plays an important role in APC maturation and their migration from the tumor to the lymph nodes, resulting in elevated antigen presentation and T cell activation. Anti-CD40 agonist antibodies produce substantial responses and durable anticancer immunity in animal models, an effect mediated at least in part by cytotoxic T-cells (see, e.g., Johnson et al. Clin Cancer Res. 21: 1321-1328, 2015; and Vonderheide and Glennie, Clin Cancer Res. 19:1035-43, 2013). General examples of CD40 agonists include an antibody or antigen-binding fragment or small molecule or ligand that specifically binds to CD40 and increases one or more of its immunostimulatory activities. Specific examples include CP-870,893, dacetuzumab, Chi Lob 7/4, ADC-1013, CD40L, rhCD40L, and antigen-binding fragments thereof. In some embodiments, the agent is a GITR agonist. Glucocorticoid-Induced TNFR family Related gene (GITR) increases T cell expansion, inhibits the suppressive activity of Tregs, and extends the survival of T-effector cells. GITR agonists have been shown to promote an anti-tumor response through loss of Treg lineage stability (see, e.g., Schaer et al., Cancer Immunol Res. 1:320- 31, 2013). These diverse mechanisms show that GITR plays an important role in initiating the immune response in the lymph nodes and in maintaining the immune response in the tumor tissue. Its ligand is GITRL. General examples of GITR agonists include an antibody or antigen-binding fragment or small molecule or ligand that specifically binds to GITR and increases one or more of its immunostimulatory activities. Specific examples include GITRL, INCAGN01876, DTA-1, MEDI1873, and antigen-binding fragments thereof.

In some embodiments, the agent is a CD137 agonist. CD137 (4-1BB) is a member of the tumor necrosis factor (TNF) receptor family, and crosslinking of CD137 enhances T-cell proliferation, IL-2 secretion, survival, and cytolytic activity. CD137-mediated signaling also protects T-cells such as CD8+ T-cells from activation-induced cell death. General examples of CD137 agonists include an antibody or antigen-binding fragment or small molecule or ligand that specifically binds to CD137 and increases one or more of its immunostimulatory activities. Specific examples include the CD137 (or 4-1BB) ligand (see, e.g., Shao and Schwarz, J Leukoc Biol. 89:21-9, 2011) and the antibody utomilumab, including antigen-binding fragments thereof.

In some embodiments, the agent is a CD27 agonist. Stimulation of CD27 increases antigen- specific expansion of naive T cells and contributes to T-cell memory and long-term maintenance of T- cell immunity. Its ligand is CD70. The targeting of human CD27 with an agonist antibody stimulates T-cell activation and antitumor immunity (see, e.g., Thomas et al., Oncoimmunology. 2014;3:e27255. doi: 10.4161/onci.27255; and He et al ., J Immunol. 191:4174-83, 2013). General examples of CD27 agonists include an antibody or antigen-binding fragment or small molecule or ligand that specifically binds to CD27 and increases one or more of its immunostimulatory activities. Specific examples include CD70 and the antibodies varlilumab and CDX-1127 (1F5), including antigen-binding fragments thereof.

In some embodiments, the agent is a CD28 agonist. CD28 is constitutively expressed CD4+ T cells some CD8+ T cells. Its ligands include CD80 and CD86, and its stimulation increases T-cell expansion. General examples of CD28 agonists include an antibody or antigen-binding fragment or small molecule or ligand that specifically binds to CD28 and increases one or more of its immunostimulatory activities. Specific examples include CD80, CD86, the antibody TAB08, and antigen-binding fragments thereof.

In some embodiments, the agent is CD226 agonist. CD226 is a stimulating receptor that shares ligands with TIGIT, and opposite to TIGIT, engagement of CD226 enhances T-cell activation (see, e.g., Kurtulus et al., J Clin Invest. 125:4053-4062, 2015; Bottino et al., J Exp Med. 1984:557- 567, 2003; and Tahara-Hanaoka et al., Int Immunol. 16:533-538, 2004). General examples of CD226 agonists include an antibody or antigen-binding fragment or small molecule or ligand (e.g., CD112, CD 155) that specifically binds to CD226 and increases one or more of its immunostimulatory activities.

In some embodiments, the agent is an HVEM agonist. Herpesvirus entry mediator (HVEM), also known as tumor necrosis factor receptor superfamily member 14 (TNFRSF14), is a human cell surface receptor of the TNF-receptor superfamily. HVEM is found on a variety of cells including T- cells, APCs, and other immune cells. Unlike other receptors, HVEM is expressed at high levels on resting T-cells and down-regulated upon activation. It has been shown that HVEM signaling plays a crucial role in the early phases of T-cell activation and during the expansion of tumor-specific lymphocyte populations in the lymph nodes. General examples of HVEM agonists include an antibody or antigen-binding fragment or small molecule or ligand that specifically binds to HVEM and increases one or more of its immunostimulatory activities.

The various cancer immunotherapy agents described herein can be combined with any one or more of the antibodies, and antigen-binding fragments thereof, described herein, and used according to any one or more of the methods or compositions described herein.

Certain combination therapies employ one or more chemotherapeutic agents, for example, small molecule chemotherapeutic agents. Non-limiting examples of chemotherapeutic agents include alkylating agents, anti-metabolites, cytotoxic antibiotics, topoisomerase inhibitors (type 1 or type II), an anti-microtubule agents, among others.

Examples of alkylating agents include nitrogen mustards (e.g., mechlorethamine, cyclophosphamide, mustine, melphalan, chlorambucil, ifosfamide , and busulfan), nitrosoureas (e.g., N-Nitroso-N-methylurea (MNU), carmustine (BCNU), lomustine (CCNU), semustine (MeCCNU), fotemustine, and streptozotocin), tetrazines (e.g., dacarbazine, mitozolomide, and temozolomide), aziridines (e.g., thiotepa, mytomycin, and diaziquone (AZQ)), cisplatins and derivatives thereof (e.g., carboplatin and oxaliplatin), and non-classical alkylating agents (optionally procarbazine and hexamethylmelamine).

Examples of anti-metabolites include anti-folates (e.g., methotrexate and pemetrexed), fluoropyrimidines (e.g., 5-fluorouracil and capecitabine), deoxynucleoside analogues (e.g., ancitabine, enocitabine, cytarabine, gemcitabine, decitabine, azacitidine, fludarabine, nelarabine, cladribine, clofarabine, fludarabine, and pentostatin), and thiopurines (e.g., thioguanine and mercaptopurine);

Examples of cytotoxic antibiotics include anthracyclines (e.g., doxorubicin, daunorubicin, epirubicin, idarubicin, pirarubicin, aclarubicin, and mitoxantrone), bleomycins, mitomycin C, mitoxantrone, and actinomycin. Examples of topoisomerase inhibitors include camptothecin, irinotecan, topotecan, etoposide, doxorubicin, mitoxantrone, teniposide, novobiocin, merbarone, and aclarubicin.

Examples of anti-microtubule agents include taxanes (e.g., paclitaxel and docetaxel) and vinca alkaloids (e.g., vinblastine, vincristine, vindesine, vinorelbine). The various chemotherapeutic agents described herein can be combined with any one or more of the antibodies, and antigen-binding fragments thereof, described herein, and used according to any one or more of the methods or compositions described herein.

Certain combination therapies employ at least one hormonal therapeutic agent. General examples of hormonal therapeutic agents include hormonal agonists and hormonal antagonists. Particular examples of hormonal agonists include progestogen (progestin), corticosteroids (e.g., prednisolone, methylprednisolone, dexamethasone), insulin like growth factors, VEGF derived angiogenic and lymphangiogenic factors (e.g., VEGF-A, VEGF-A145, VEGF-A165, VEGF-C, VEGF-D, PIGF-2), fibroblast growth factor (FGF), galectin, hepatocyte growth factor (HGF), platelet derived growth factor (PDGF), transforming growth factor (TGF)-beta, androgens, estrogens, and somatostatin analogs. Examples of hormonal antagonists include hormone synthesis inhibitors such as aromatase inhibitors and gonadotropin-releasing hormone (GnRH)s agonists (e.g., leuprolide, goserelin, triptorelin, histrelin) including analogs thereof. Also included are hormone receptor antagonist such as selective estrogen receptor modulators (SERMs; e.g., tamoxifen, raloxifene, toremifene) and anti-androgens (e.g., flutamide, bicalutamide, nilutamide).

Also included are hormonal pathway inhibitors such as antibodies directed against hormonal receptors. Examples include inhibitors of the the IGF receptor (e.g., IGF-IR1) such as cixutumumab, dalotuzumab, figitumumab, ganitumab, istiratumab, and robatumumab; inhibitors of the vascular endothelial growth factor receptors 1, 2 or 3 (VEGFR1, VEGFR2 or VEGFR3) such as alacizumab pegol, bevacizumab, icrucumab, ramucirumab; inhibitors of the TGF-beta receptors Rl, R2, and R3 such as fresolimumab and metelimumab; inhibitors of c-Met such as naxitamab; inhibitors of the EGF receptor such as cetuximab, depatuxizumab mafodotin, futuximab, imgatuzumab, laprituximab emtansine, matuzumab, modotuximab, necitumumab, nimotuzumab, panitumumab, tomuzotuximab, and zalutumumab; inhibitors of the FGF receptor such as aprutumab ixadotin and bemarituzumab; and inhibitors of the PDGF receptor such as olaratumab and tovetumab.

The various hormonal therapeutic agents described herein can be combined with any one or more of the various antibodies, or antigen-binding fragments thereof, described herein, and used according to any one or more of the methods or compositions described herein.

Certain combination therapies employ at least one kinase inhibitor, including tyrosine kinase inhibitors. Examples of kinase inhibitors include, without limitation, adavosertib, afanitib, aflibercept, axitinib, bevacizumab, bosutinib, cabozantinib, cetuximab, cobimetinib, crizotinib, dasatinib, entrectinib, erdafitinib, erlotinib, fostamitinib, gefitinib, ibrutinib, imatinib, lapatinib, lenvatinib, mubritinib, nilotinib, panitumumab, pazopanib, pegaptanib, ponatinib, ranibizumab, regorafenib, ruxolitinib, sorafenib, sunitinib, SU6656, tofacitinib, trastuzumab, vandetanib, and vemuafenib.

The various kinase inhibitors described herein can be combined with any one or more of the various antibodies, or antigen-binding fragments thereof, described herein, and used according to any one or more of the methods or compositions described herein. In some embodiments, the methods and pharmaceutical compositions described herein increase median survival time of a subject by 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks, 15 weeks, 20 weeks, 25 weeks, 30 weeks, 40 weeks, or longer. In certain embodiments, the methods and pharmaceutical compositions described herein increase median survival time of a subject by 1 year, 2 years, 3 years, or longer. In some embodiments, the methods and pharmaceutical compositions increase progression-free survival by 2 weeks, 3 weeks, 4 weeks, 5 weeks, 6 weeks, 7 weeks, 8 weeks, 9 weeks, 10 weeks or longer. In certain embodiments, the methods and pharmaceutical compositions described herein increase progression-free survival by 1 year, 2 years, 3 years, or longer.

In certain embodiments, the methods and therapeutic compositions described herein are sufficient to result in tumor regression, as indicated by a statistically significant decrease in the amount of viable tumor, for example, at least a 10%, 20%, 30%, 40%, 50% or greater decrease in tumor mass, or by altered (e.g., decreased with statistical significance) scan dimensions. In certain embodiments, the methods and therapeutic compositions described herein are sufficient to result in stable disease.

In certain embodiments, the methods and therapeutic compositions described herein are sufficient to result in clinically relevant reduction in symptoms of a particular disease indication known to the skilled clinician.

For in vivo use, as noted above, for the treatment of human or non-human mammalian disease or testing, the protein agents described herein (e.g., antibodies, or antigen-binding fragments thereof) are incorporated into one or more therapeutic or pharmaceutical or diagnostic compositions prior to administration.

Thus, certain embodiments relate to pharmaceutical or therapeutic compositions that comprise at least one antibody, or antigen-binding fragment thereof, as described herein. In some instances, a pharmaceutical or therapeutic composition comprises one or more of the protein agents described herein in combination with a pharmaceutically- or physiologically -acceptable carrier or excipient. Certain pharmaceutical or therapeutic compositions further comprise at least one additional agent, for example, a cancer immunotherapy agent, a chemotherapeutic agent, a hormonal therapeutic agent, and/or a kinase inhibitor, as described herein.

Some therapeutic compositions comprise (and certain methods utilize) only one antibody, or antigen-binding fragment thereof. Certain therapeutic compositions comprise (and certain methods utilize) a mixture of at least two, three, four, or five different antibodies, or antigen-binding fragments thereof.

In particular embodiments, the pharmaceutical or therapeutic compositions comprising at least one antibody, or antigen-binding fragment thereof, is substantially pure on a protein basis or a weight-weight basis, for example, the composition has a purity of at least about 80%, 85%, 90%,

95%, 98%, or 99% on a protein basis or a weight-weight basis. In some embodiments, the protein agents described herein do not form aggregates, have a desired solubility, and/or have an immunogenicity profde that is suitable for use in humans, as known in the art. Thus, in some embodiments, the therapeutic composition comprising a protein agent is substantially aggregate-free. For example, certain compositions comprise less than about 10% (on a protein basis) high molecular weight aggregated proteins, or less than about 5% high molecular weight aggregated proteins, or less than about 4% high molecular weight aggregated proteins, or less than about 3% high molecular weight aggregated proteins, or less than about 2 % high molecular weight aggregated proteins, or less than about 1% high molecular weight aggregated proteins. Some compositions comprise a protein agent that is at least about 50%, about 60%, about 70%, about 80%, about 90% or about 95% monodisperse with respect to its apparent molecular mass.

In some embodiments, a protein agent is concentrated to about or at least about 0.1 mg/ml,

0.2 mg/ml, 0.3 mg/ml, 0.4 mg/ml, 0.5 mg/ml, 0.6, 0.7, 0.8, 0.9, 1 mg/ml, 2 mg/ml, 3 mg/ml, 4 mg/ml, 5 mg/ml, 6 mg/ml, 7 mg/ml, 8 mg/ml, 9 mg/ml, 10 mg/ml, 11, 12, 13, 14 or 15 mg/ml and are formulated for biotherapeutic uses.

To prepare a therapeutic or pharmaceutical composition, an effective or desired amount of one or more agents is mixed with any pharmaceutical carrier(s) or excipient known to those skilled in the art to be suitable for the particular agent and/or mode of administration. A pharmaceutical carrier may be liquid, semi-liquid or solid. Solutions or suspensions used for parenteral, intradermal, subcutaneous or topical application may include, for example, a sterile diluent (such as water), saline solution (e.g., phosphate buffered saline; PBS), fixed oil, polyethylene glycol, glycerin, propylene glycol or other synthetic solvent; antimicrobial agents (such as benzyl alcohol and methyl parabens); antioxidants (such as ascorbic acid and sodium bisulfite) and chelating agents (such as ethylenediaminetetraacetic acid (EDTA)); buffers (such as acetates, citrates and phosphates). If administered intravenously (e.g., by IV infusion), suitable carriers include physiological saline or phosphate buffered saline (PBS), and solutions containing thickening and solubilizing agents, such as glucose, polyethylene glycol, polypropylene glycol and mixtures thereof.

Administration of agents described herein, in pure form or in an appropriate therapeutic or pharmaceutical composition, can be carried out via any of the accepted modes of administration of agents for serving similar utilities. The therapeutic or pharmaceutical compositions can be prepared by combining an agent-containing composition with an appropriate physiologically acceptable carrier, diluent or excipient, and may be formulated into preparations in solid, semi-solid, liquid or gaseous forms, such as tablets, capsules, powders, granules, ointments, solutions, suppositories, injections, inhalants, gels, microspheres, and aerosols. In addition, other pharmaceutically active ingredients (including other small molecules as described elsewhere herein) and/or suitable excipients such as salts, buffers and stabilizers may, but need not, be present within the composition.

Administration may be achieved by a variety of different routes, including oral, parenteral, nasal, intravenous, intradermal, intramuscular, subcutaneous or topical. Preferred modes of administration depend upon the nature of the condition to be treated or prevented. Particular embodiments include administration by IV infusion.

Carriers can include, for example, pharmaceutically- or physiologically -acceptable carriers, excipients, or stabilizers that are non-toxic to the cell or mammal being exposed thereto at the dosages and concentrations employed. Often the physiologically-acceptable carrier is an aqueous pH buffered solution. Examples of physiologically acceptable carriers include buffers such as phosphate, citrate, and other organic acids; antioxidants including ascorbic acid; low molecular weight (less than about 10 residues) polypeptide; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, arginine or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; and/or nonionic surfactants such as polysorbate 20 (TWEEN™) polyethylene glycol (PEG), and poloxamers (PLURONICS™), and the like.

In some embodiments, one or more agents can be entrapped in microcapsules prepared, for example, by coacervation techniques or by interfacial polymerization (for example, hydroxymethylcellulose or gelatin-microcapsules and poly-(methylmethacylate)microcapsules, respectively), in colloidal drug delivery systems (for example, liposomes, albumin microspheres, microemulsions, nano-particles and nanocapsules), or in macroemulsions. Such techniques are disclosed in Remington’s Pharmaceutical Sciences, 16th edition, Oslo, A., Ed., (1980). The particle(s) or liposomes may further comprise other therapeutic or diagnostic agents.

The precise dosage and duration of treatment is a function of the disease being treated and may be determined empirically using known testing protocols or by testing the compositions in model systems known in the art and extrapolating therefrom. Controlled clinical trials may also be performed. Dosages may also vary with the severity of the condition to be alleviated. A pharmaceutical composition is generally formulated and administered to exert a therapeutically useful effect while minimizing undesirable side effects. The composition may be administered one time, or may be divided into a number of smaller doses to be administered at intervals of time. For any particular subject, specific dosage regimens may be adjusted over time according to the individual need.

Typical routes of administering these and related therapeutic or pharmaceutical compositions thus include, without limitation, oral, topical, transdermal, inhalation, parenteral, sublingual, buccal, rectal, vaginal, and intranasal. The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intrastemal injection or infusion techniques. Therapeutic or pharmaceutical compositions according to certain embodiments of the present disclosure are formulated so as to allow the active ingredients contained therein to be bioavailable upon administration of the composition to a subject or patient. Compositions that will be administered to a subject or patient may take the form of one or more dosage units, where for example, a tablet may be a single dosage unit, and a container of a herein described agent in aerosol form may hold a plurality of dosage units. Actual methods of preparing such dosage forms are known, or will be apparent, to those skilled in this art; for example, see Remington: The Science and Practice of Pharmacy, 20th Edition (Philadelphia College of Pharmacy and Science, 2000). The composition to be administered will typically contain a therapeutically effective amount of an agent described herein, for treatment of a disease or condition of interest.

A therapeutic or pharmaceutical composition may be in the form of a solid or liquid. In one embodiment, the carrier(s) are particulate, so that the compositions are, for example, in tablet or powder form. The carrier(s) may be liquid, with the compositions being, for example, an oral oil, injectable liquid or an aerosol, which is useful in, for example, inhalatory administration. When intended for oral administration, the pharmaceutical composition is preferably in either solid or liquid form, where semi-solid, semi-liquid, suspension and gel forms are included within the forms considered herein as either solid or liquid. Certain embodiments include sterile, injectable solutions.

As a solid composition for oral administration, the pharmaceutical composition may be formulated into a powder, granule, compressed tablet, pill, capsule, chewing gum, wafer or the like. Such a solid composition will typically contain one or more inert diluents or edible carriers. In addition, one or more of the following may be present: binders such as carboxymethylcellulose, ethyl cellulose, microcrystalline cellulose, gum tragacanth or gelatin; excipients such as starch, lactose or dextrins, disintegrating agents such as alginic acid, sodium alginate, Primogel, com starch and the like; lubricants such as magnesium stearate or Sterotex; glidants such as colloidal silicon dioxide; sweetening agents such as sucrose or saccharin; a flavoring agent such as peppermint, methyl salicylate or orange flavoring; and a coloring agent. When the pharmaceutical composition is in the form of a capsule, for example, a gelatin capsule, it may contain, in addition to materials of the above type, a liquid carrier such as polyethylene glycol or oil.

The therapeutic or pharmaceutical composition may be in the form of a liquid, for example, an elixir, syrup, solution, emulsion or suspension. The liquid may be for oral administration or for delivery by injection, as two examples. When intended for oral administration, preferred composition contain, in addition to the present compounds, one or more of a sweetening agent, preservatives, dye/colorant and flavor enhancer. In a composition intended to be administered by injection, one or more of a surfactant, preservative, wetting agent, dispersing agent, suspending agent, buffer, stabilizer and isotonic agent may be included.

The liquid therapeutic or pharmaceutical compositions, whether they be solutions, suspensions or other like form, may include one or more of the following adjuvants: sterile diluents such as water for injection, saline solution, preferably physiological saline, Ringer’s solution, isotonic sodium chloride, fixed oils such as synthetic mono or diglycerides which may serve as the solvent or suspending medium, polyethylene glycols, glycerin, propylene glycol or other solvents; antibacterial agents such as benzyl alcohol or methyl paraben; antioxidants such as ascorbic acid or sodium bisulfite; chelating agents such as ethylenediaminetetraacetic acid; buffers such as acetates, citrates or phosphates and agents for the adjustment of tonicity such as sodium chloride or dextrose. The parenteral preparation can be enclosed in ampoules, disposable syringes or multiple dose vials made of glass or plastic. Physiological saline is a preferred adjuvant. An injectable pharmaceutical composition is preferably sterile.

A liquid therapeutic or pharmaceutical composition intended for either parenteral or oral administration should contain an amount of an agent such that a suitable dosage will be obtained. Typically, this amount is at least 0.01% of the agent of interest in the composition. When intended for oral administration, this amount may be varied to be between 0.1 and about 70% of the weight of the composition. Certain oral therapeutic or pharmaceutical compositions contain between about 4% and about 75% of the agent of interest. In certain embodiments, therapeutic or pharmaceutical compositions and preparations are prepared so that a parenteral dosage unit contains between 0.01 to 10% by weight of the agent of interest prior to dilution.

The therapeutic or pharmaceutical compositions may be intended for topical administration, in which case the carrier may suitably comprise a solution, emulsion, ointment or gel base. The base, for example, may comprise one or more of the following: petrolatum, lanolin, polyethylene glycols, bee wax, mineral oil, diluents such as water and alcohol, and emulsifiers and stabilizers. Thickening agents may be present in a therapeutic or pharmaceutical composition for topical administration. If intended for transdermal administration, the composition may include a transdermal patch or iontophoresis device.

The therapeutic or pharmaceutical compositions may be intended for rectal administration, in the form, for example, of a suppository, which will melt in the rectum and release the drug. The composition for rectal administration may contain an oleaginous base as a suitable nonirritating excipient. Such bases include, without limitation, lanolin, cocoa butter, and polyethylene glycol.

The therapeutic or pharmaceutical composition may include various materials, which modify the physical form of a solid or liquid dosage unit. For example, the composition may include materials that form a coating shell around the active ingredients. The materials that form the coating shell are typically inert, and may be selected from, for example, sugar, shellac, and other enteric coating agents. Alternatively, the active ingredients may be encased in a gelatin capsule. The therapeutic or pharmaceutical compositions in solid or liquid form may include a component that binds to agent and thereby assists in the delivery of the compound. Suitable components that may act in this capacity include monoclonal or polyclonal antibodies, one or more proteins or a liposome.

The therapeutic or pharmaceutical composition may consist essentially of dosage units that can be administered as an aerosol. The term aerosol is used to denote a variety of systems ranging from those of colloidal nature to systems consisting of pressurized packages. Delivery may be by a liquefied or compressed gas or by a suitable pump system that dispenses the active ingredients. Aerosols may be delivered in single phase, bi-phasic, or tri-phasic systems in order to deliver the active ingredient(s). Delivery of the aerosol includes the necessary container, activators, valves, subcontainers, and the like, which together may form a kit. One of ordinary skill in the art, without undue experimentation may determine preferred aerosols.

The compositions described herein may be prepared with carriers that protect the agents against rapid elimination from the body, such as time release formulations or coatings. Such carriers include controlled release formulations, such as, but not limited to, implants and microencapsulated delivery systems, and biodegradable, biocompatible polymers, such as ethylene vinyl acetate, poly anhydrides, poly glycolic acid, polyorthoesters, polylactic acid and others known to those of ordinary skill in the art.

The therapeutic or pharmaceutical compositions may be prepared by methodology well known in the pharmaceutical art. For example, a therapeutic or pharmaceutical composition intended to be administered by injection may comprise one or more of salts, buffers and/or stabilizers, with sterile, distilled water so as to form a solution. A surfactant may be added to facilitate the formation of a homogeneous solution or suspension. Surfactants are compounds that non-covalently interact with the agent so as to facilitate dissolution or homogeneous suspension of the agent in the aqueous delivery system.

The therapeutic or pharmaceutical compositions may be administered in a therapeutically effective amount, which will vary depending upon a variety of factors including the activity of the specific compound employed; the metabolic stability and length of action of the compound; the age, body weight, general health, sex, and diet of the subject; the mode and time of administration; the rate of excretion; the drug combination; the severity of the particular disorder or condition; and the subject undergoing therapy. In some instances, a therapeutically effective daily dose is (for a 70 kg mammal) from about 0.001 mg/kg (i.e., ~ 0.07 mg) to about 100 mg/kg (i.e., ~ 7.0 g); preferably a therapeutically effective dose is (for a 70 kg mammal) from about 0.01 mg/kg (i.e., ~ 0.7 mg) to about 50 mg/kg (i.e., ~ 3.5 g); more preferably a therapeutically effective dose is (for a 70 kg mammal) from about 1 mg/kg (i.e., ~ 70 mg) to about 25 mg/kg (i.e., ~ 1.75 g). In some embodiments, the therapeutically effective dose is administered on a weekly, bi-weekly, or monthly basis. In specific embodiments, the therapeutically effective dose is administered on a weekly, bi-weekly, or monthly basis, for example, at a dose of about 1-10 or 1-5 mg/kg, or about 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 mg/kg.

The combination therapies described herein may include administration of a single pharmaceutical dosage formulation, which contains a protein agent described herein (e.g., antibody, or antigen-binding fragment thereof) and an additional therapeutic agent (e.g., cancer immunotherapy agent, chemotherapeutic agent, hormonal therapeutic agent, kinase inhibitor), as well as administration of compositions comprising a protein agent and an additional therapeutic agent in its own separate pharmaceutical dosage formulation. For example, a protein agent described herein and additional therapeutic agent can be administered to the subject together in a single oral dosage composition such as a tablet or capsule, or each agent administered in separate oral dosage formulations. Similarly, a protein agent described herein and additional therapeutic agent can be administered to the subject together in a single parenteral dosage composition such as in a saline solution or other physiologically acceptable solution, or each agent administered in separate parenteral dosage formulations. As another example, for cell-based therapies, a protein agent described herein can be mixed with the cells prior to administration, administered as part of a separate composition, or both. Where separate dosage formulations are used, the compositions can be administered at essentially the same time, i.e., concurrently, or at separately staggered times, i.e., sequentially and in any order; combination therapy is understood to include all these regimens.

Also included are patient care kits, comprising (a) at least one protein agent described herein, as described herein; and optionally (b) at least one additional therapeutic agent (e.g., cancer immunotherapy agent, chemotherapeutic agent, hormonal therapeutic agent, kinase inhibitor). In certain kits, (a) and (b) are in separate therapeutic compositions. In some kits, (a) and (b) are in the same therapeutic composition.

The kits herein may also include a one or more additional therapeutic agents or other components suitable or desired for the indication being treated, or for the desired diagnostic application. The kits herein can also include one or more syringes or other components necessary or desired to facilitate an intended mode of delivery (e.g., stents, implantable depots, etc.).

In some embodiments, a patient care kit contains separate containers, dividers, or compartments for the composition(s) and informational material(s). For example, the composition(s) can be contained in a bottle, vial, or syringe, and the informational material(s) can be contained in association with the container. In some embodiments, the separate elements of the kit are contained within a single, undivided container. For example, the composition is contained in a bottle, vial or syringe that has attached thereto the informational material in the form of a label. In some embodiments, the kit includes a plurality (e.g., a pack) of individual containers, each containing one or more unit dosage forms (e.g., a dosage form described herein) of a protein agent described herein and optionally at least one additional therapeutic agent. For example, the kit includes a plurality of syringes, ampules, foil packets, or blister packs, each containing a single unit dose of a protein agent described herein and optionally at least one additional therapeutic agent. The containers of the kits can be air tight, waterproof (e.g., impermeable to changes in moisture or evaporation), and/or light-tight.

The patient care kit optionally includes a device suitable for administration of the composition, e.g., a syringe, inhalant, dropper (e.g., eye dropper), swab (e.g., a cotton swab or wooden swab), or any such delivery device. In some embodiments, the device is an implantable device that dispenses metered doses of the agent(s). Also included are methods of providing a kit, e.g., by combining the components described herein.

Some embodiments relate, in part, to diagnostic applications for detecting the presence of cells or tissues expressing FAP and/or B7H3. Thus, the present disclosure provides methods of detecting FAP and/or BH73 in a sample, such as detection of cells or tissues expressing FAP and/or B7H3. Such methods can be applied in a variety of known detection formats, including, but not limited to immunohistochemistry (IHC), immunocytochemistry (ICC), in situ hybridization (ISH), whole-mount in situ hybridization (WISH), fluorescent DNA in situ hybridization (FISH), flow cytometry, enzyme immuno-assay (EIA), and enzyme linked immuno-assay (ELISA).

ISH is a type of hybridization that uses a labeled complementary DNA or RNA strand (i.e., primary binding agent) to localize a specific DNA or RNA sequence in a portion or section of a cell or tissue (in situ), or if the tissue is small enough, the entire tissue (whole mount ISH). This approach is distinct from immunohistochemistry, which localizes proteins in tissue sections using an antibody as a primary binding agent. DNA ISH can be used on genomic DNA to determine the structure of chromosomes. Fluorescent DNA ISH (FISH) can, for example, be used in medical diagnostics to assess chromosomal integrity. RNA ISH (hybridization histochemistry) is used to measure and localize mRNAs and other transcripts within tissue sections or whole mounts.

The disclosure further provides kits for detecting FAP and/or BH73, or cells or tissues expressing FAP and/or B7H3 in a sample, wherein the kits contain at least one antibody, polynucleotide, vector or host cell as described herein. In certain embodiments, a kit may comprise buffers, enzymes, labels, substrates, beads or other surfaces to which the antibodies of the disclosure are attached, and the like, and instructions for use.

Expression and Purification Systems

Certain embodiments include methods and related compositions for expressing and purifying recombinant proteins, such as an antibody, or an antigen-binding fragment thereof, or a fusion protein comprising the same, described herein. Such recombinant proteins can be conveniently prepared using standard protocols as described for example in Sambrook, et ak, (1989, supra), in particular Sections 16 and 17; Ausubel et ak, (1994, supra), in particular Chapters 10 and 16; and Coligan et ak, Current Protocols in Protein Science (John Wiley & Sons, Inc. 1995-1997), in particular Chapters 1, 5 and 6. As one general example, recombinant proteins may be prepared by a procedure including one or more of the steps of: (a) preparing one or more vectors or constructs comprising one or more polynucleotide sequences that encode one or more proteins described herein, which are operably linked to one or more regulatory elements; (b) introducing the one or more vectors or constructs into one or more host cells; (c) culturing the one or more host cell to express the one or more proteins; and (d) isolating the one or more proteins from the host cell.

To express a desired polypeptide, a nucleotide sequence encoding a first and/or second polypeptide chain of a protein may be inserted into appropriate expression vector(s), i.e., vector(s) which contain the necessary elements for the transcription and translation of the inserted coding sequence. Methods which are well known to those skilled in the art may be used to construct expression vectors containing sequences encoding a polypeptide of interest and appropriate transcriptional and translational control elements. These methods include in vitro recombinant DNA techniques, synthetic techniques, and in vivo genetic recombination. Such techniques are described in Sambrook et al., Molecular Cloning, A Laboratory Manual (1989), and Ausubel et al., Current Protocols in Molecular Biology (1989).

A variety of expression vector/host systems are known and may be utilized to contain and express polynucleotide sequences. These include, but are not limited to, microorganisms such as bacteria transformed with recombinant bacteriophage, plasmid, or cosmid DNA expression vectors; yeast transformed with yeast expression vectors; insect cell systems infected with virus expression vectors (e.g., baculovirus); plant cell systems transformed with virus expression vectors (e.g., cauliflower mosaic virus, CaMV; tobacco mosaic virus, TMV) or with bacterial expression vectors (e.g., Ti or pBR322 plasmids); or animal cell systems, including mammalian cell and more specifically human cell systems.

The “control elements” or “regulatory sequences” present in an expression vector are those non-translated regions of the vector— enhancers, promoters, 5 ’ and 3 ’ untranslated regions-which interact with host cellular proteins to carry out transcription and translation. Such elements may vary in their strength and specificity. Depending on the vector system and host utilized, any number of suitable transcription and translation elements, including constitutive and inducible promoters, may be used. For example, when cloning in bacterial systems, inducible promoters such as the hybrid lacZ promoter of the PBLUESCRIPT phagemid (Stratagene, La Jolla, Calif.) or PSPORT1 plasmid (Gibco BRL, Gaithersburg, Md.) and the like may be used. In mammalian cell systems, promoters from mammalian genes or from mammalian viruses are generally preferred. If it is necessary to generate a cell line that contains multiple copies of the sequence encoding a polypeptide, vectors based on SV40 or EBV may be advantageously used with an appropriate selectable marker.

In bacterial systems, a number of expression vectors may be selected depending upon the use intended for the expressed polypeptide. For example, when large quantities are needed, vectors may be used which direct high level expression of antibodies, or antigen-binding fragments thereof, which are readily purified. Such vectors include but are not limited to, the multifunctional E. coli cloning and expression vectors such as BLUESCRIPT (Stratagene), in which the sequence encoding the polypeptide of interest may be ligated into the vector in frame with sequences for the amino-terminal Met and the subsequent 7 residues of b-galactosidase so that a hybrid protein is produced; pIN vectors (Van Heeke & Schuster, J. Biol. Chem. 264:5503 5509 (1989)); and the like. pGEX Vectors (Promega, Madison, Wis.) may also be used to express polypeptides with glutathione S-transferase (GST). In general, such polypeptides are soluble and can easily be purified from lysed cells by adsorption to glutathione-agarose beads followed by elution in the presence of free glutathione. Proteins made in such systems may be designed to include heparin, thrombin, or factor XA protease cleavage sites so that the cloned polypeptide of interest can be released from the GST moiety at will.

Certain embodiments employ E. coli-based expression systems (see, e.g., Structural Genomics Consortium et al., Nature Methods. 5:135-146, 2008). These and related embodiments may rely partially or totally on ligation-independent cloning (LIC) to produce a suitable expression vector. In specific embodiments, protein expression may be controlled by a T7 RNA polymerase (e.g., pET vector series). These and related embodiments may utilize the expression host strain BL21(DE3), a /.DE3 lysogen of BL21 that supports T7-mediated expression and is deficient in Ion and ompT proteases for improved target protein stability. Also included are expression host strains carrying plasmids encoding tRNAs rarely used in E. coli, such as ROSETTA ^™ (DE3) and Rosetta 2 (DE3) strains. Cell lysis and sample handling may also be improved using reagents sold under the trademarks BENZONASE® nuclease and BUGBUSTER® Protein Extraction Reagent. For cell culture, auto-inducing media can improve the efficiency of many expression systems, including high- throughput expression systems. Media of this type (e.g., OVERNIGHT EXPRESS™ Autoinduction System) gradually elicit protein expression through metabolic shift without the addition of artificial inducing agents such as IPTG. Particular embodiments employ hexahistidine tags (such as those sold under the trademark HIS*TAG® fusions), followed by immobilized metal affinity chromatography (IMAC) purification, or related techniques. In certain aspects, however, clinical grade proteins can be isolated from E. coli inclusion bodies, without or without the use of affinity tags (see, e.g., Shimp et ak, Protein Expr Purif. 50:58-67, 2006). As a further example, certain embodiments may employ a cold-shock induced E. coli high-yield production system, because over-expression of proteins in Escherichia coli at low temperature improves their solubility and stability (see, e.g., Qing et ak,

Nature Biotechnology. 22:877-882, 2004).

Also included are high-density bacterial fermentation systems. For example, high cell density cultivation of Ralstonia eutropha allows protein production at cell densities of over 150 g/L, and the expression of recombinant proteins at titers exceeding 10 g/L.

In the yeast Saccharomyces cerevisiae, a number of vectors containing constitutive or inducible promoters such as alpha factor, alcohol oxidase, and PGH may be used. For reviews, see Ausubel et ak (supra) and Grant et ak, Methods Enzymoh 153:516-544 (1987). Also included are Pichia pandoris expression systems (see, e.g., Li et ak, Nature Biotechnology. 24, 210 - 215, 2006; and Hamilton et ak, Science, 301:1244, 2003). Certain embodiments include yeast systems that are engineered to selectively glycosylate proteins, including yeast that have humanized N-glycosylation pathways, among others (see, e.g., Hamilton et ak, Science. 313:1441-1443, 2006; Wildt et ak, Nature Reviews Microbiol. 3:119-28, 2005; and Gerngross et ak, Nature-Biotechnology. 22:1409 -1414, 2004; U.S. Patent Nos. 7,629,163; 7,326,681; and 7,029,872). Merely by way of example, recombinant yeast cultures can be grown in Fernbach Flasks or 15L, 50L, 100L, and 200L fermentors, among others.

In cases where plant expression vectors are used, the expression of sequences encoding polypeptides may be driven by any of a number of promoters. For example, viral promoters such as the 35S and 19S promoters of CaMV may be used alone or in combination with the omega leader sequence from TMV (Takamatsu, EMBO J. 6:307-311 (1987)). Alternatively, plant promoters such as the small subunit of RUBISCO or heat shock promoters may be used (Coruzzi et al., EMBO J. 3:1671-1680 (1984); Broglie et al., Science 224:838-843 (1984); and Winter et al., Results Probl. Cell Differ. 17:85-105 (1991)). These constructs can be introduced into plant cells by direct DNA transformation or pathogen-mediated transfection. Such techniques are described in a number of generally available reviews (see, e.g., Hobbs in McGraw Hill, Yearbook of Science and Technology, pp. 191-196 (1992)).

An insect system may also be used to express a polypeptide of interest. For example, in one such system, Autographa californica nuclear polyhedrosis virus (AcNPV) is used as a vector to express foreign genes in Spodoptera frugiperda cells or in Trichoplusia cells. The sequences encoding the polypeptide may be cloned into a non-essential region of the virus, such as the polyhedrin gene, and placed under control of the polyhedrin promoter. Successful insertion of the polypeptide-encoding sequence will render the polyhedrin gene inactive and produce recombinant virus lacking coat protein. The recombinant viruses may then be used to infect, for example, S. frugiperda cells or Trichoplusia cells in which the polypeptide of interest may be expressed (Engelhard et al., Proc. Natl. Acad. Sci. U.S.A. 91:3224-3227 (1994)). Also included are baculovirus expression systems, including those that utilize SF9, SF21, and T. ni cells (see, e.g., Murphy and Piwnica-Worms, Curr Protoc Protein Sci. Chapter 5:Unit5.4, 2001). Insect systems can provide post-translation modifications that are similar to mammalian systems.

In mammalian host cells, a number of viral-based expression systems are generally available. For example, in cases where an adenovirus is used as an expression vector, sequences encoding a polypeptide of interest may be ligated into an adenovirus transcription/translation complex consisting of the late promoter and tripartite leader sequence. Insertion in a non-essential El or E3 region of the viral genome may be used to obtain a viable virus which is capable of expressing the polypeptide in infected host cells (Eogan & Shenk, Proc. Natl. Acad. Sci. U.S.A. 81:3655-3659 (1984)). In addition, transcription enhancers, such as the Rous sarcoma virus (RSV) enhancer, may be used to increase expression in mammalian host cells.

Examples of useful mammalian host cell lines include monkey kidney CV1 line transformed by SV40 (COS-7, ATCC CRL 1651); human embryonic kidney line (293 or 293 cells sub-cloned for growth in suspension culture, Graham et al., J. Gen Virol. 36:59 (1977)); baby hamster kidney cells (BHK, ATCC CCL 10); mouse sertoli cells (TM4, Mather, Biol. Reprod. 23:243-251 (1980)); monkey kidney cells (CV1 ATCC CCL 70); African green monkey kidney cells (VERO-76, ATCC CRL-1587); human cervical carcinoma cells (HELA, ATCC CCL 2); canine kidney cells (MDCK, ATCC CCL 34); buffalo rat liver cells (BRL 3A, ATCC CRL 1442); human lung cells (W138, ATCC CCL 75); human liver cells (Hep G2, HB 8065); mouse mammary tumor (MMT 060562, ATCC CCL51); TR1 cells (Mather et al., Annals N.Y. Acad. Sci. 383:44-68 (1982)); MRC 5 cells; FS4 cells; and a human hepatoma line (Hep G2). Other useful mammalian host cell lines include Chinese hamster ovary (CHO) cells, including DHFR-CHO cells (Urlaub et al., PNAS USA 77:4216 (1980)); and myeloma cell lines such as NSO and Sp2/0. For a review of certain mammalian host cell lines suitable for protein production, see, e.g., Yazaki and Wu, Methods in Molecular Biology, Vol. 248 (B. K.C Lo, ed., Humana Press, Totowa, N.J., 2003), pp. 255-268. Certain preferred mammalian cell expression systems include CHO and HEK293-cell based expression systems. Mammalian expression systems can utilize attached cell lines, for example, in T-flasks, roller bottles, or cell factories, or suspension cultures, for example, in 1L and 5L spinners, 5L, 14L, 40L, 100L and 200L stir tank bioreactors, or 20/50L and 100/200L WAVE bioreactors, among others known in the art.

Also included is the cell-free expression of proteins. These and related embodiments typically utilize purified RNA polymerase, ribosomes, tRNA and ribonucleotides; these reagents may be produced by extraction from cells or from a cell-based expression system.

Specific initiation signals may also be used to achieve more efficient translation of sequences encoding a polypeptide of interest. Such signals include the ATG initiation codon and adjacent sequences. In cases where sequences encoding the polypeptide, its initiation codon, and upstream sequences are inserted into the appropriate expression vector, no additional transcriptional or translational control signals may be needed. However, in cases where only coding sequence, or a portion thereof, is inserted, exogenous translational control signals including the ATG initiation codon should be provided. Furthermore, the initiation codon should be in the correct reading frame to ensure translation of the entire insert. Exogenous translational elements and initiation codons may be of various origins, both natural and synthetic. The efficiency of expression may be enhanced by the inclusion of enhancers which are appropriate for the particular cell system which is used, such as those described in the literature (Scharf. et ak, Results Probl. Cell Differ. 20:125-162 (1994)).

In addition, a host cell strain may be chosen for its ability to modulate the expression of the inserted sequences or to process the expressed protein in the desired fashion. Such modifications of the polypeptide include, but are not limited to, post-translational modifications such as acetylation, carboxylation, glycosylation, phosphorylation, lipidation, and acylation. Post-translational processing which cleaves a “prepro” form of the protein may also be used to facilitate correct insertion, folding and/or function. Different host cells such as yeast, CHO, HeLa, MDCK, HEK293, and W138, in addition to bacterial cells, which have or even lack specific cellular machinery and characteristic mechanisms for such post-translational activities, may be chosen to ensure the correct modification and processing of the foreign protein.

For long-term, high-yield production of recombinant proteins, stable expression is generally preferred. For example, cell lines which stably express a polynucleotide of interest may be transformed using expression vectors which may contain viral origins of replication and/or endogenous expression elements and a selectable marker gene on the same or on a separate vector. Following the introduction of the vector, cells may be allowed to grow for about 1-2 days in an enriched media before they are switched to selective media. The purpose of the selectable marker is to confer resistance to selection, and its presence allows growth and recovery of cells which successfully express the introduced sequences. Resistant clones of stably transformed cells may be proliferated using tissue culture techniques appropriate to the cell type. Transient production, such as by transient transfection or infection, can also be employed. Exemplary mammalian expression systems that are suitable for transient production include HEK293 and CHO-based systems.

Any number of selection systems may be used to recover transformed or transduced cell lines. These include, but are not limited to, the herpes simplex virus thymidine kinase (Wigler et al., Cell 11:223-232 (1977)) and adenine phosphoribosyltransferase (Lowy et al., Cell 22:817-823 (1990)) genes which can be employed in tk- or aprt- cells, respectively. Also, antimetabolite, antibiotic or herbicide resistance can be used as the basis for selection; for example, dhfr which confers resistance to methotrexate (Wigler et al., Proc. Natl. Acad. Sci. U.S.A. 77:3567-70 (1980)); npt, which confers resistance to the aminoglycosides, neomycin and G-418 (Colbere-Garapin et al., J. Mol. Biol. 150:1- 14 (1981)); and als or pat, which confer resistance to chlorsulfuron and phosphinotricin acetyltransferase, respectively (Murry, supra). Additional selectable genes have been described, for example, trpB, which allows cells to utilize indole in place of tryptophan, or hisD, which allows cells to utilize histinol in place of histidine (Hartman & Mulligan, Proc. Natl. Acad. Sci. U.S.A. 85:8047-51 (1988)). The use of visible markers has gained popularity with such markers as green fluorescent protein (GFP) and other fluorescent proteins (e.g., RFP, YFP), anthocyanins, b-glucuronidase and its substrate GUS, and luciferase and its substrate luciferin, being widely used not only to identify transformants, but also to quantify the amount of transient or stable protein expression attributable to a specific vector system (see, e.g., Rhodes et al., Methods Mol. Biol. 55:121-131 (1995)).

Also included are high-throughput protein production systems, or micro-production systems. Certain aspects may utilize, for example, hexa-histidine fusion tags for protein expression and purification on metal chelate-modified slide surfaces or MagneHis Ni-Particles (see, e.g., Kwon et al., BMC Biotechnol. 9:72, 2009; and Lin et al., Methods Mol Biol. 498:129-41, 2009)). Also included are high-throughput cell-free protein expression systems (see, e.g., Sitaraman et al., Methods Mol Biol. 498:229-44, 2009).

A variety of protocols for detecting and measuring the expression of polynucleotide-encoded products, using binding agents or antibodies such as polyclonal or monoclonal antibodies specific for the product, are known in the art. Examples include enzyme-linked immunosorbent assay (ELISA), western immunoblots, radioimmunoassays (RIA), and fluorescence activated cell sorting (FACS). These and other assays are described, among other places, in Hampton et al., Serological Methods, a Laboratory Manual (1990) and Maddox et al., J. Exp. Med. 158:1211-1216 (1983).

A wide variety of labels and conjugation techniques are known by those skilled in the art and may be used in various nucleic acid and amino acid assays. Means for producing labeled hybridization or PCR probes for detecting sequences related to polynucleotides include oligolabeling, nick translation, end-labeling or PCR amplification using a labeled nucleotide. Alternatively, the sequences, or any portions thereof may be cloned into a vector for the production of an mRNA probe. Such vectors are known in the art, are commercially available, and may be used to synthesize RNA probes in vitro by addition of an appropriate RNA polymerase such as T7, T3, or SP6 and labeled nucleotides. These procedures may be conducted using a variety of commercially available kits. Suitable reporter molecules or labels, which may be used include radionuclides, enzymes, fluorescent, chemiluminescent, or chromogenic agents as well as substrates, cofactors, inhibitors, magnetic particles, and the like.

Host cells transformed with one or more polynucleotide sequences of interest may be cultured under conditions suitable for the expression and recovery of the protein from cell culture. Certain specific embodiments utilize serum free cell expression systems. Examples include HEK293 cells and CHO cells that can grown on serum free medium (see, e.g., Rosser et ak, Protein Expr. Purif. 40:237- 43, 2005; and U.S. Patent number 6,210,922).

A protein produced by a recombinant cell may be secreted or contained intracellularly depending on the sequence and/or the vector used. As will be understood by those of skill in the art, expression vectors containing polynucleotides may be designed to contain signal sequences which direct secretion of the encoded polypeptide through a prokaryotic or eukaryotic cell membrane. Other recombinant constructions may be used to join sequences encoding a polypeptide of interest to nucleotide sequence encoding a polypeptide domain which will facilitate purification and/or detection of soluble proteins. Examples of such domains include cleavable and non-cleavable affinity purification and epitope tags such as avidin, FLAG tags, poly -histidine tags (e.g., 6xHis), cMyc tags, V5-tags, glutathione S-transferase (GST) tags, and others.

The protein produced by a recombinant cell can be purified and characterized according to a variety of techniques known in the art. Exemplary systems for performing protein purification and analyzing protein purity include fast protein liquid chromatography (FPLC) (e.g., AKTA and Bio-Rad FPLC systems), high-pressure liquid chromatography (HPLC) (e.g., Beckman and Waters HPLC). Exemplary chemistries for purification include ion exchange chromatography (e.g., Q, S), size exclusion chromatography, salt gradients, affinity purification (e.g., Ni, Co, FLAG, maltose, glutathione, protein A/G), gel filtration, reverse-phase, ceramic HYPERD® ion exchange chromatography, and hydrophobic interaction columns (HIC), among others known in the art. Also included are analytical methods such as SDS-PAGE (e.g., coomassie, silver stain), immunoblot, Bradford, and ELISA, which may be utilized during any step of the production or purification process, typically to measure the purity of the protein composition.

Also included are methods of concentrating the proteins described herein (antibodies, antigen binding fragments theroef, fusion proteins), and composition comprising concentrated soluble proteins. In some aspects, such concentrated solutions comprise protein(s) at a concentration of about or at least about 5 mg/mL, 8 mg/mL, 10 mg/mL, 15 mg/mL, 20 mg/mL, or more.

In some aspects, such compositions may be substantially monodisperse, meaning that a protein exists primarily (i.e., at least about 90%, or greater) in one apparent molecular weight form when assessed for example, by size exclusion chromatography, dynamic light scattering, or analytical ultracentrifugation.

In some aspects, such compositions have a purity (on a protein basis) of at least about 90%, or in some aspects at least about 95% purity, or in some embodiments, at least 98% purity. Purity may be determined via any routine analytical method as known in the art.

In some aspects, such compositions have a high molecular weight aggregate content of less than about 10%, compared to the total amount of protein present, or in some embodiments such compositions have a high molecular weight aggregate content of less than about 5%, or in some aspects such compositions have a high molecular weight aggregate content of less than about 3%, or in some embodiments a high molecular weight aggregate content of less than about 1%. High molecular weight aggregate content may be determined via a variety of analytical techniques including for example, by size exclusion chromatography, dynamic light scattering, or analytical ultracentrifugation.

Examples of concentration approaches contemplated herein include lyophilization, which is typically employed when the solution contains few soluble components other than the protein of interest. Lyophilization is often performed after HPLC run, and can remove most or all volatile components from the mixture. Also included are ultrafiltration techniques, which typically employ one or more selective permeable membranes to concentrate a protein solution. The membrane allows water and small molecules to pass through and retains the protein; the solution can be forced against the membrane by mechanical pump, gas pressure, or centrifugation, among other techniques.

In certain embodiments, a protein in a composition has a purity of at least about 90%, as measured according to routine techniques in the art. In certain embodiments, such as diagnostic compositions or certain pharmaceutical or therapeutic compositions, a protein composition has a purity of at least about 95%, or at least about 97% or 98% or 99%. In some embodiments, such as when being used as reference or research reagents, proteins can be of lesser purity, and may have a purity of at least about 50%, 60%, 70%, or 80%. Purity can be measured overall or in relation to selected components, such as other proteins, e.g., purity on a protein basis.

Purified proteins can also be characterized according to their biological characteristics. Binding affinity and binding kinetics can be measured according to a variety of techniques known in the art, such as Biacore® and related technologies that utilize surface plasmon resonance (SPR), an optical phenomenon that enables detection of unlabeled interactants in real time. SPR-based biosensors can be used in determination of active concentration, screening and characterization in terms of both affinity and kinetics. The presence or levels of one or more biological activities can be measured according to cell-based assays, including those that utilize at least one IL-2 receptor and/or IL-15 receptor, which is optionally functionally coupled to a readout or indicator, such as a fluorescent or luminescent indicator of biological activity, as described herein. In certain embodiments, as noted above, a composition is substantially endotoxin free, including, for example, about 95% endotoxin free, preferably about 99% endotoxin free, and more preferably about 99.99% endotoxin free. The presence of endotoxins can be detected according to routine techniques in the art, as described herein. In specific embodiments, a proteim composition is made from a eukaryotic cell such as a mammalian or human cell in substantially serum free media. In certain embodiments, as noted herein, an composition has an endotoxin content of less than about 10 EU/mg of protein, or less than about 5 EU/mg of protein, less than about 3 EU/mg of protein, or less than about 1 EU/mg of protein.

In certain embodiments, a composition comprises less than about 10% wt/wt high molecular weight aggregates, or less than about 5% wt/wt high molecular weight aggregates, or less than about 2% wt/wt high molecular weight aggregates, or less than about or less than about 1% wt/wt high molecular weight aggregates.

Also included are protein-based analytical assays and methods, which can be used to assess, for example, protein purity, size, solubility, and degree of aggregation, among other characteristics. Protein purity can be assessed a number of ways. For instance, purity can be assessed based on primary structure, higher order structure, size, charge, hydrophobicity, and glycosylation. Examples of methods for assessing primary structure include N- and C-terminal sequencing and peptide-mapping (see, e.g., Allen et al., Biologicals. 24:255-275, 1996)). Examples of methods for assessing higher order structure include circular dichroism (see, e.g., Kelly et al., Biochim Biophys Acta. 1751:119- 139, 2005), fluorescent spectroscopy (see, e.g., Meagher et al., J. Biol. Chem. 273:23283-89, 1998), FT-IR, amide hydrogen-deuterium exchange kinetics, differential scanning calorimetry, NMR spectroscopy, immunoreactivity with conformationally sensitive antibodies. Higher order structure can also be assessed as a function of a variety of parameters such as pH, temperature, or added salts. Examples of methods for assessing protein characteristics such as size include analytical ultracentrifugation and size exclusion HPLC (SEC-HPLC), and exemplary methods for measuring charge include ion-exchange chromatography and isolectric focusing. Hydrophobicity can be assessed, for example, by reverse-phase HPLC and hydrophobic interaction chromatography HPLC. Glycosylation can affect pharmacokinetics (e.g., clearance), conformation or stability, receptor binding, and protein function, and can be assessed, for example, by mass spectrometry and nuclear magnetic resonance (NMR) spectroscopy.

As noted above, certain embodiments include the use of SEC-HPLC to assess protein characteristics such as purity, size (e.g., size homogeneity) or degree of aggregation, and/or to purify proteins, among other uses. SEC, also including gel-filtration chromatography (GFC) and gel- permeation chromatography (GPC), refers to a chromatographic method in which molecules in solution are separated in a porous material based on their size, or more specifically their hydrodynamic volume, diffusion coefficient, and/or surface properties. The process is generally used to separate biological molecules, and to determine molecular weights and molecular weight distributions of polymers. Typically, a biological or protein sample (such as a protein extract produced according to the protein expression methods provided herein and known in the art) is loaded into a selected size-exclusion column with a defined stationary phase (the porous material), preferably a phase that does not interact with the proteins in the sample. In certain aspects, the stationary phase is composed of inert particles packed into a dense three-dimensional matrix within a glass or steel column. The mobile phase can be pure water, an aqueous buffer, an organic solvent, or a mixture thereof. The stationary -phase particles typically have small pores and/or channels which only allow molecules below a certain size to enter. Large particles are therefore excluded from these pores and channels, and their limited interaction with the stationary phase leads them to elute as a “totally- excluded” peak at the beginning of the experiment. Smaller molecules, which can fit into the pores, are removed from the flowing mobile phase, and the time they spend immobilized in the stationary- phase pores depends, in part, on how far into the pores they penetrate. Their removal from the mobile phase flow causes them to take longer to elute from the column and results in a separation between the particles based on differences in their size. A given size exclusion column has a range of molecular weights that can be separated. Overall, molecules larger than the upper limit will not be trapped by the stationary phase, molecules smaller than the lower limit will completely enter the solid phase and elute as a single band, and molecules within the range will elute at different rates, defined by their properties such as hydrodynamic volume. For examples of these methods in practice with pharmaceutical proteins, see Bruner et ak, Journal of Pharmaceutical and Biomedical Analysis. 15: 1929-1935, 1997.

Protein purity for clinical applications is also discussed, for example, by Anicetti et al.

(Trends in Biotechnology. 7:342-349, 1989). More recent techniques for analyzing protein purity include, without limitation, the LabChip GXII, an automated platform for rapid analysis of proteins and nucleic acids, which provides high throughput analysis of titer, sizing, and purity analysis of proteins. In certain non-limiting embodiments, clinical grade proteins can be obtained by utilizing a combination of chromatographic materials in at least two orthogonal steps, among other methods (see, e.g., Therapeutic Proteins: Methods and Protocols. Vol. 308, Eds., Smales and James, Humana Press Inc., 2005). Typically, protein agents are substantially endotoxin-free, as measured according to techniques known in the art and described herein.

Protein solubility assays are also included. Such assays can be utilized, for example, to determine optimal growth and purification conditions for recombinant production, to optimize the choice of buffer(s), and to optimize the choice of proteins and variants thereof. Solubility or aggregation can be evaluated according to a variety of parameters, including temperature, pH, salts, and the presence or absence of other additives. Examples of solubility screening assays include, without limitation, microplate-based methods of measuring protein solubility using turbidity or other measure as an end point, high-throughput assays for analysis of the solubility of purified recombinant proteins (see, e.g., Stenvall et ak, Biochim Biophys Acta. 1752:6-10, 2005), assays that use structural complementation of a genetic marker protein to monitor and measure protein folding and solubility in vivo (see, e.g., Wigley et al., Nature Biotechnology. 19:131-136, 2001), and electrochemical screening of recombinant protein solubility in Escherichia coli using scanning electrochemical microscopy (SECM) (see, e.g., Nagamine et al., Biotechnology and Bioengineering. 96:1008-1013, 2006), among others. Proteins with increased solubility (or reduced aggregation) can be identified or selected for according to routine techniques in the art, including simple in vivo assays for protein solubility (see, e.g., Maxwell et al., Protein Sci. 8:1908-11, 1999).

Protein solubility and aggregation can also be measured by dynamic light scattering techniques. Aggregation is a general term that encompasses several types of interactions or characteristics, including soluble/insoluble, covalent/noncovalent, reversible/irreversible, and native/denatured interactions and characteristics. For protein therapeutics, the presence of aggregates is typically considered undesirable because of the concern that aggregates may cause an immunogenic reaction (e.g., small aggregates), or may cause adverse events on administration (e.g., particulates). Dynamic light scattering refers to a technique that can be used to determine the size distribution profde of small particles in suspension or polymers such as proteins in solution. This technique, also referred to as photon correlation spectroscopy (PCS) or quasi-elastic light scattering (QELS), uses scattered light to measure the rate of diffusion of the protein particles. Fluctuations of the scattering intensity can be observed due to the Brownian motion of the molecules and particles in solution. This motion data can be conventionally processed to derive a size distribution for the sample, wherein the size is given by the Stokes radius or hydrodynamic radius of the protein particle. The hydrodynamic size depends on both mass and shape (conformation). Dynamic scattering can detect the presence of very small amounts of aggregated protein (<0.01% by weight), even in samples that contain a large range of masses. It can also be used to compare the stability of different formulations, including, for example, applications that rely on real-time monitoring of changes at elevated temperatures. Accordingly, certain embodiments include the use of dynamic light scattering to analyze the solubility and/or presence of aggregates in a sample that contains a protein of the present disclosure.

Although the foregoing embodiments have been described in some detail by way of illustration and example for purposes of clarity of understanding, it will be readily apparent to one of ordinary skill in the art in light of the teachings of this disclosure that certain changes and modifications may be made thereto without departing from the spirit or scope of the appended claims. The following examples are provided by way of illustration only and not by way of limitation. Those of skill in the art will readily recognize a variety of noncritical parameters that could be changed or modified to yield essentially similar results.

Examples

Example 1 Engineering of Antibodies to Human FAPa and Human B7H3

Experiments were performed to engineer antibodies which specifically bind to human FAPa, human B7H3, or both human FAPa and human B7H3. Amino acid sequences of CDRs, heavy chains, and light chains are shown in Table SI and Table S2, and alignments of the variable regions are show in Figures 18A-18L.

Plasmids coding for heavy chain and light chain were constructed by standard gene synthesis, followed by sub-cloning into pTT5 expression vector. The antibody names relative to the heavy and light chain variable region alignments in Figures 18A-18L are provided in Table El below

Production, purification and characterization. Antibodies were produced by transient transfection in Expi293 cells and purified by a one-step purification process of MabSelect SuRe chromatography (GE Healthcare).

Expi293 expression supernatant was characterized by reduced SDS-PAGE to confirm the expression of antibodies. Representative SDS-APGE results are shown in Figure 6A. Most of the antibodies showed good expression. Purified proteins were characterized by SDS-PAGE for purity assessment and showed good purity as shown in Figures 6B and 6C.

Purified proteins were also characterized by high performance liquid chromatography (HPLC) for homogeneity assessment. HPLC analysis was performed using Zenix-C column (Sepax) and Acquity Arc (Agilent) according to the manufacturer’s instructions. Representative HPLC results are shown in Figures 7A-7F. Most of the proteins showed one single peak, indicating good homogeneity.

ELISA analysis. The binding activity and specificity of expression supernatant and purified antibodies were determined by ELISA. Microtitre plates were coated with purified FAPa protein or goat anti-mouse Fc antibody (Sigma) overnight at 4°C. The next day, plates were washed with PBS and blocked with 3% non-fat dry milk in PBS. B7H3-muFc fusion protein was captured by goat anti mouse Fc antibody. Serially diluted expression supernatants or antibodies were added for binding to the immobilized antigen. Bound antibodies were detected with peroxidase-conjugated anti-human IgG secondary antibody (Jackson Immunoresearch).

The results of expression supernatant are summarized in Figures 8-14. Most of the expressed antibodies exhibited good binding activity to human FAPa protein as shown in Figures 8A-8L and Figures 9A-9Q. Some of the expressed antibodies exhibited good binding activity to B7H3 protein as shown in Figures 10-13. The results of purified protein are summarized in Figure 14A-14N.

Consistent with the results of expression supernatant, most purified antibodies showed binding activity to human FAPa protein (Figure 14A-14E) and some antibodies showed binding activity to B7H3 protein (Figures 14F-14N).

FACS analysis. FACS analysis was performed for purified antibodies. Binding of Expi293 expression supernatant or purified antibodies to FAPa and/or B7H3 expressing cells was determined by flow cytometry lx 10 ⁵ cells were incubated for 1 hour at 4°C with purified antibodies. After washing twice with cold FACS buffer (PBS containing 1% BSA and 0.1% sodium azide), cell surface bound antibody was detected by incubating the cells with phycoerythrin (PE)-labeled anti-human IgG antibody (Jackson Immuno, Cat# 109-116-098) for 1 hour at 4°C. Cells were washed twice in FACS buffer and analyzed using Guava EasyCyte HT (Merck Millipore).

Representative FACS data are shown in Figures 15-17. Most of the antibodies exhibited binding activity to human FAPa and many exhibited binding activity to B7H3 protein. Among these antibodies, P28832158 exhibited good binding activity to both human FAPa and B7H3 protein (see Figures 17H and 171).