Description

The present invention relates to the use of targeted radioactive compounds (TRC) for the treatment of inflammatory and/or autoimmune disorders, as well as immunosuppressive disorders.

Despite of the progress of molecular medicine within the last 40 years which enabled a detection of the changes which contribute to the pathophysiology of a variety of diseases on the molecular level, the majority of the more severe diseases can only be treated symptomatically. This unsatisfactory situation is due to the fact that the molecular cause of the respective disease may not be known or the causative event of the disease may not be accessible to curative intervention. Therefore, even the most recent drug development efforts of pharmaceutical industry in the field of inflammation- autoimmunity and cancer are directed towards targets which are associated with the disease but mostly not causative for the disease. Consequently, the result of these efforts will be drugs which may delay disease progression or improve the disease status without any hope for cure. Therefore, inflammatory/autoimmune diseases such as severe rheumatoid arthritis, multiple sclerosis, scleroderma pigmentosa, systemic lupus erythematodes, colitis ulcerosa, Crohn's disease as well as the majority of malignant diseases cannot be cured with the actual therapeutic approaches.

The previously mentioned inflammatory/autoimmune diseases are caused by an uncontrolled activation of the immune system against self-antigens of the patient. The actual therapies directed against mediators of the disease such as cytokines and/or their receptors can delay the progression of the disease but can not hinder the progression finally resulting in complete disablement.

In case of metastatic tumours, the beneficial impact of actual therapeutics is even less pronounced. A few months of life prolongation may be achieved nowadays with targeted drugs or combinations with chemotherapy, but the side effects and the associated costs are a major burden to the patients before they die from their disease.

To improve this unsatisfactory situation, novel treatment paradigms have to be implemented which address the cause of the disease finally allowing cure.

A complete elimination of diseased bone-marrow by administering a radiolabeled antibody conjugate is described in DE 198 13 687.

During preclinical and clinical efforts to establish a better treatment procedure for haematopoietic malignancies according to WO2007/062855, the inventors unexpectedly observed that an antibody targeted radio therapy (ATRT) procedure with anti CD66 allows to treat and cure patients with non- malignant disorders such as inflammatory disorders, autoimmune disorders, immunosuppressive disorders, if combined with haematopoietic stem cell transplantation.

More particularly, clinical investigations by the inventors have shown that ATRT with anti CD66 allows localizing high doses of yttrium-90 to bone marrow and spleen.

Interestingly, ATRT with anti CD66 antibody was given to patients without any detectable side effect. Amazingly, treatment related death was 0 percent in contrast to conventional transplantation regimens where 10-15% of patients die as a consequence to transplantation procedure related side effects.

Astonishingly, the inventors have also shown in a limited number of patients with myeloma or leukemias that the treatment procedure induced a high complete remission rate resulting in long term survivors both in the autologous as well as allogeneic haematopoietic stem cell transplantation regimen.

Both the good tolerability of the novel ATRT haematopoietic transplantation regimen as well as the significant improvements in patient's survival in the leukemia treatment allows extending the actual haematopoietic stem cell transplantation technology to non-malignant diseases.

The innovative changes in this treatment regimen are the elimination of antitumor agents such as high dose melphalan treatment the bone marrow reconstitution with autologous or allogeneic haematopoietic stem cells and the ATRT with reduced doses compared to the regimen applied to patients with leukemias or myeloma. The allogeneic haematopoietic stem cells can be obtained from cord blood and extended in vitro using for example peptide ligands which bind to receptors on stem cells allowing the extension of stem cells under in vitro conditions. Preferred media for expanding stem cells under in vitro conditions may comprise cytokines and/or interleukins, e.g. selected from the group comprising thrombopoietin (TPO), granulocyte- stimulating factor (G-CSF), stem cell factor (SCF), interleukin-3 (IL-3) and interleukin-6 (IL-6). Especially preferred are combinations of several or all of these compounds.

Intravenous injection of the autologous or allogeneic stem cells in patients whose bone marrow was depleted with ATRT will result in repopulation of the bone marrow niches and will transfer a normal immune system into the recipients.

Haematopoietic stem cell recipients who previously had autoimmune disease will be cured since the diseased autoimmune system of the patients is now reconstituted with healthy unprimed bone marrow of allogeneic donors. Depending on the purity of the transferred allogeneic haematopoietic stem cells (stem cells preferably have to be free of any primed T-cells which may be the cause of allogeneic host versus graft reactions), recipients should have a life without autoimmune disease and without the need for medication with immunosuppressive drugs. Alternatively, autologous stem cells, e.g. bone marrow-derived stem cells, may be transplanted.

Thus, a subject matter of the present application is the use of a targeted radioactive compound (TRC) for the manufacture of a medicament for the administration in the therapy of a disorder selected from inflammatory and/or autoimmune disorders as well as immunosuppressive disorders, particularly in a human patient, wherein the TRC comprises a CD66-binding component which may be covalently bound to a radionuclide.

According to the present invention, the term "inflammatory and/or autoimmune disorders" particularly relates to disorders which are accompanied by, associated with or caused by inflammation and/or autoimmune reactions, e.g. rheumatoid arthritis and other types of arthritic disorders, multiple sclerosis and other neurodegenerative disorders, scleroderma pigmentosa, systemic lupus erythematodes, and disorders of the gastrointestinal system such as colitis ulcerosa and Crohn' disease. According to the present invention, the term "immunosuppressive disorders" relates to disorders which are accompanied by, associated with or caused by a suppression of the immune system, e.g. AIDS or other disorders caused by infections with immunodeficiency viruses such as HIV, or common variable immunodeficiency disorders (CVIDs) caused by primary antibody deficiency syndromes, as described in Wood (Curr. Opin. Hematol. 2010, May 3 Epub), the content of which is herein incorporated by reference.

In the case of patients with HIV, it is preferred to transfer haematopoietic stem cells from allogeneic donors who have a mutated receptor e.g. selected from chemokine receptor CCR2, CCR5 or SDF1 not allowing HIV to infect T- cells. After bone marrow depletion, allogeneic stem cell transfer and reconstitution of the bone marrow, HIV will not be able to replicate anymore in the new donor T-cells which carry chemokine receptor mutations such as CCR2-64I, CCR5-D32, or SDF1 -3'A. The therapeutic TRC administration is preferably followed by allogeneic cell, e.g. stem cell, transplantation. Suitable cells for transplantation are haematopoietic stem cells from allogeneic donors, which may be obtained by procedures as described in Karussis & Vaknin-Dembinsky (Expert Rev Clin Immunol 6 (2010), 347-352), Gratwohl et al. (JAMA 303 (2010), 1617-1624), Alchalby & Kroger (Curr Hematol Malig Rep 5 (2010), 53-61 ), Pessina et al. (Cell Biol Int (2010) Apr 16 Epub), Cerdan & Bhatia (Int J Dev Biol (2010) Mar 15 Epub), Bueno et al. (Stem Cell Rev (2010) Feb 24 Epub), Jing et al. (Haematologica 95 (2010), 542-550), Sun et al. (Blood 1 15 (2010), 1709- 1717), Madlambayan & Rogers (Regen Med 1 (2006), 777-787); Huang et al. (Cell Transplant 16 (2007), 579-585) and Chen et al. (Zhonghua Xue Ye Xue Za Zhi 27 (2006), 390-393), the contents of which are herein incorporated by reference. In some embodiments, allogeneic stem cells may be derived from umbilical cord blood and expanded in vitro using suitable ligands, e.g. peptide or peptide-derived ligands. Alternatively, autologous stem cells may be transplanted. Autologous stem cells may be derived from the bone marrow. They may be used after expansion or without expansion.

The radionuclide of the TRC may be a therapeutically effective radionuclide, i.e. a radionuclide which is suitable for the treatment of haematological malignant disorders by irradiation, preferentially a β-emitter. For example, the therapeutically effective radionuclide may be yttrium-90 ( ⁹⁰ Y), iodine-131 ( ¹³¹ l), samarium-153 ( ⁵³ Sm), holmium-166 ( ¹⁶⁶ Ho), rhenium-186 ( ¹⁸⁶ Re), rhenium-188 ( ¹⁸⁸ Re) or another β- or β/γ-emitting radionuclide, or may be an a-emitter such as astatine-21 1 ( ²¹¹ At), bismuth-212 ( ^{2 2} Bi), bismuth-213 ( ^{2 3} Bi) or actinium-225 ( ²²⁵ Ac).

The therapy may additionally comprise administration of radionuclides suitable for imaging before therapeutic irradiation of bone marrow cells. For this purpose, the radionuclide of the TRC may also be an imaging radionuclide, i.e. a radionuclide which is suitable for monitoring and/or determining pharmacokinetics of the TRC allowing dosimetry. For example, the imaging radionuclide may be a γ-emitter such as indium-1 1 1 ( ln), iodine-131 ( ¹³¹ l) or techneticum-99m ( ^99m Tc) or another γ-emitter.

In an especially preferred embodiment the invention encompasses determining the therapeutically effective dose of a therapeutic TRC prior to administration. This determination may be carried out individually for a subject to be treated, or for a group of subjects, e.g. based on the severity or progression of the disease. For example, the invention may comprise the administration of a TRC comprising an imaging radionuclide and a subsequent administration of a TRC comprising a therapeutically effective radionuclide. By means of first administering an imaging TRC, the effective dose of the subsequently administered therapeutic TRC may be individually determined and/or adjusted for a respective subject, e.g. a human patient. In this embodiment, the CD66-binding component of the imaging TRC and the therapeutic TRC is preferably identical, at least with respect to the CD66- binding specificity and/or affinity.

It should be noted, however, that administration of an imaging TRC prior to administration of a therapeutic TRC might not be necessary, if sufficient patient data has been collected, e.g. in a database, to determine a therapeutically active amount of the TRC. Thus, a further preferred embodiment of the invention comprises determining a therapeutically effective dose of a TRC by evaluating pre-existing data, e.g. from a database. Alternatively or additionally, bone marrow biopsies can be used to estimate the patients' bone marrow to predict its eligibility for therapeutic TRC.

The CD66-binding component is preferably a polypeptide comprising at least one antibody binding domain, for example an antibody, particularly a monoclonal antibody, a chimeric antibody, a humanized antibody, a recombinant antibody, such as a single chain antibody or fragment thereof, e.g. proteolytic antibody fragments such as Fab-, Fab'- or F(ab) ₂ -fragments or recombinant antibody fragments, such as single chain Fv-fragments. The CD66-binding component may also be a fusion polypeptide comprising at least one antibody binding domain and a further domain, e.g. an effector domain such as an enzyme or cytokine. Alternatively, the CD66-binding molecule may be an artificial binder, e.g. a scaffold polypeptide, such as an ankyrin, an anticalin, a modified fibronectin III domain, a lipocalin, an ubiquitin, a modified protein A, a C-type lectin, a FYN SH3 domain, a camelid antibody, a cys-knot domain or another protein domain designed for ligand binding as described in Nature Biotech 23 (2005), 1493-1494, the content of which is herein incorporated by reference.

In a preferred embodiment, the CD66-binding component selectively binds to the human CD66 antigen or an epitope thereof, e.g. CD66a, b, c, or e. In an especially preferred embodiment the CD66-binding component is the BW250/183 antibody. Murine, humanized and recombinant forms of this antibody are described in EP-A-0 388 914, EP-A-0 585 570 and EP-A-0 972 528, which are herein incorporated by reference.

The radionuclide is preferably linked to the CD66-binding component via a chelating agent, with the linkage preferably being a covalent linkage. In this embodiment, the CD66-binding component may be designated as targeted radioactive chelate. More preferably the radionuclide is linked to the CD66- binding component via a structure of the formula

[(chelating agent)-(R ¹ ) _p -(R ² -R ³ ) _n ] _m -(CD66-binding component) wherein n is 0 or 1 ,

m is 1 to 15,

p is 0 or 1 ,

R ¹ and R ³ are independently selected from the group consisting of -NHCSNH-, -NHCONH-, -NHCOCH ₂ S-, -S-S-, -NH-NH-, -NH-, -S-,

-CONHNH-, -SCH ₂ CH ₂ COONH-, -SCH ₂ CH ₂ S0 ₂ -, -SCH ₂ CH ₂ S0 ₂ NH-, -CONH-, -0-CH ₂ CH ₂ 0-, -CO-, -COO-, -NH-0-, -CONHO-, -S- (CH ₂ ) ₃ C(NH)NH-, -NH-COO-, -O- and

and

R ² is selected from the group consisting of Ci-Ci ₈ alkylene, branched Ci-Ci ₈ , -CH ₂ -C ₆ H ₁₀ -, p-alkylphenylene, p-phenylene, m-phenylene, p- alkyloxyphenylene, naphthylene, -[CH CH O] - , -[CH CH SOCH CH 1 -, - [CH ₂ CH ₂ S0 ₂ CH ₂ CH ₂ ] _x -, or -[NHCHR ₄ CO] _y -, wherein x is 1 to 200, y is 1 to 20, and wherein R ₄ is selected from the group consisting of H-, Me-, HSCH ₂ -, isopropyl, but-2-yl, CH ₃ SCH ₂ CH ₂ -, benzyl, 1 H-indol-3-yl-methyl, HOCH ₂ -, HOOCCH ₂ -, CH ₃ CH(OH)-, HOOCCH ₂ CH ₂ -, 4-hydroxybenzyl, H ₂ NCOCH ₂ -, H ₂ NCOCH ₂ CH ₂ -, 4-aminobut-1 -yl, 2-guanidinoethyl, 1 H-imidazol-5-yl-methyl and 2-methylprop-1 -yl.

For example, the chelating agent may be selected from the group consisting of diethylenetriaminepentaacetic acid (DTPA), 1 ,4,7, 10- tetraazacyclododecane-N,N ^' ,N ^" ,N ^{" '} -tetraacetic acid (DOTA), 1 ,4,8, 1 1 - tetraazacyclotetradecane-N,N ^' ,N ^" ,N ^{" '} -tetraacetic acid (TETA), 1 ,4,7- triazonane-N,N ^' ,N ^" -triacetic acid (NOTA), 2,2'-(2-(((1 S,2S)-2- (bis(carboxymethyl)amino)cyclohexyl)-

(carboxymethyl)amino)ethylazanediyl)diacetic acid (cyclohexano-DTPA), 2,2'-(2-(((1 R,2R)-2-(bis(carboxymethyl)amino)cyclohexyl)- (carboxymethyl)amino)ethylazanediyl)diacetic acid, 2,2'-(2-(((1 S,2R)-2- (bis(carboxymethyl)amino)cyclohexyl)-

(carboxymethyl)amino)ethylazanediyl)diacetic acid, 2,2'-(2-(((1 R,2S)-2- (bis(carboxymethyl)amino)cyclohexyl)-

(carboxymethyl)amino)ethylazanediyl)diacetic acid, 2,2',2",2"'-(2,2'-(1 S,2S)- cyclohexane-1 ,2-diylbis((carboxymethyl)azanediyl)bis(ethane-2, 1 - diyl))bis(azanetriyl)tetraacetic acid, 2,2 ^, ,2",2 ^M, -(2,2 ^, -(1 S,2R)-cyclohexane-1 ,2- diylbis((carboxymethyl)azanediyl)bis(ethane-2, 1 - diyl))bis(azanetriyl)tetraacetic acid, (1 f?)-1 -benzyl- diethylenetriaminepentaacetic acid, (1 S)-1 -benzyl- diethylenetriaminepentaacetic acid, (2f?)-2-benzyl- diethylenetriaminepentaacetic acid, (2S)-2-benzyl- diethylenetriaminepentaacetic acid, (2f?)-2-benzyl-(3R)-3-methyl-DTPA, (2f?)-2-benzyl-(3S)-3-methyl-DTPA, (2S)-2-benzyl-(3S)-3-methyi-DTPA, (2S)-2-benzyl-(3R)-3-methyl-DTPA, (2R)-2-benzyl-(4f?)-4-methyl-DTPA, (2fi)-2-benzyl~(4S)-4-methyl-DTPA, (2S)-2-benzyl-(4S)-4-methyl-DTPA, (2S)-2-benzyl-(4R)-4-methyl-DTPA, (1 -benzyl-(3fi)-3-methyl-DTPA, (1 -benzyl-(3S)-3-methyl-DTPA, (1 S)-1 -benzyl-(3S)-3-methyl-DTPA, (1 S)-1 -benzyl-(3R)-3-methyl-DTPA, (1 -benzyl-(4tf)-4-methyl-DTPA, (1 -benzyl-(4S)-4-methyl-DTPA, (1 S)-1 -benzyi-(4S)-4-methyl-DTPA, (1 S)-1 -benzyl-(4f?)-4-methyl-DTPA _! 2,2'-((1 R,2R)-2-(((R)-2- (bis(carboxymethyl)amino)-3-phenylpropyl)

(carboxymethyl)amino)cyclohexylazanediyl)diacetic acid, 2,2'-((1 S,2S)-2- (((S)-2-(bis(carboxymethyl)amino)-3-phenylpropyl)

(carboxymethyl)amino)cyclohexylazanediyl)diacetic acid, 2,2'-((1 R,2R)-2- (((S)-2-(bis(carboxymethyl)amino)-3-phenylpropyl)

(carboxymethyl)amino)cyclohexylazanediyl)diacetic acid, 2,2'-((1 S,2S)-2- (((R)-2-(bis(carboxymethyl)amino)-3-phenylpropyl)

(carboxymethyi)amino)cyclohexylazanediyl)diacetic acid, 2,2'-((1 R,2S)-2- (((R)-2-(bis(carboxymethyl)amino)-3-phenylpropyl)

(carboxymethyl)amino)cyclohexylazanediyl)diacetic acid, 2,2'-((1 S,2R)-2- (((S)-2-(bis(carboxymethyl)amino)-3-phenylpropyl)

(carboxymethyl)amino)cyclohexylazanediyl)diacetic acid, 2,2'-((1 S,2R)-2- (((R)-2-(bis(carboxymethyl)amino)-3-phenylpropyl)

(carboxymethyl)amino)cyclohexylazanediyl)diacetic acid, 2,2'-((1 R,2S)-2- (((S)-2-(bis(carboxymethyl)amino)-3-phenylpropyl)

(carboxymethyl)amino)cyclohexylazanediyl)diacetic acid, (2S)-2-benzyl- 1 ,4,7, 10-tetraazacyclododecane-N ,N ^' ,N ^" ,N ^{" '} -tetraacetic acid , (2R)-2- benzyl-1 ,4,7,10-tetraazacyclododecane-N , N ^' , N ^" , N ^{" '} -tetraacetic acid, 6- benzyl- 1 ,4,8,1 1 -tetraazacyclotetradecane-N ,N ^' ,N ^" ,N ^{" '} -tetraacetic acid , 2- benzyl-1 ,4,7-triazonane-N,N ^' ,N ^" -triacetic acid, or a derivative thereof. In an especially preferred embodiment, isothiocyanato-benzyl-3-methyl- diethylenetriaminepentaacetic acid (ITC-2B3 -DTPA) is used as the chelating agent.

The administration of the therapeutic TRC for the treatment of human patients may be in a dose of > about 10 MBq/kg body weight (bw), of > about 15 MBq/kg bw, of > about 20MBq/kg bw, of > about 25 MBq/kg bw, of > about 30 MBq/kg bw or of > about 35 MBq/kg bw. The TRC may be administered according to known methods, e.g. by infusion. The inventors have found that at a dose of 25 MBq/kg the peripheral blood cells were already strongly reduced indicating that the stem cells in the bone marrow which produce the haematopoietic cells were already deleted. Thus, in some embodiments, a dose of about 20 MBq/kg to about 30 MBq/kg is suitable. In other embodiments, the dose may be up to 45 MBq/kg.

Cell transplantation may comprise autologous or allogeneic stem cell transplantation. Allogeneic stem cells may be derived from allogeneic donors or from cord blood of newborns after expansion in vitro using peptide-derived ligands to eliminate alloreactive T-cells. Autologous stem cells may be derived from the patient's bone marrow.

Preferred therapeutic protocols of the invention comprise the steps:

(a) administering an imaging TRC to the patient;

(b) administering a therapeutic TRC to the patient; and

(c) transplanting autologous or allogeneic stem cells.

The imaging TRC is preferably an indium-1 1 1 labelled anti-CD66 antibody or artificial binder. The therapeutic TRC is preferably an yttrium-90 labelled anti-CD66 antibody or artificial binder.

Further, it is preferred that the protocols do not comprise administration of an anti-tumor agent such as melphalan and/or administration of an immunosuppressive agent at least 10, 15 or 20 days before and/or after therapeutic TRC administration and/or in the period between administration of therapeutic TRC and cell transplantation.

In an especially preferred embodiment as shown in Figure 1 , the therapeutic protocols of the invention consist of the following steps:

(a) administering an imaging TRC to the patient at D -22 to -16 and determining the localization of the imaging TRC (dosimetry),

(b) administering the therapeutic TRC to the patient at D -18 to -6, preferably at D -14 to -12;

(c) transplanting autologous or allogeneic stem cells at D 0.