CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the benefit of U.S. Provisional Application Nos.:

62/960,498, filed January 13, 2020, and 63/110,251, filed November 5, 2020, each of which is hereby incorporated by reference in its entirety.

REFERENCE TO SEQUENCE LISTING SUBMITTED ELECTRONICALLY [0002] The content of the electronically submitted sequence listing in ASCII text file

(Name: “713280_HMW-039PC_SL.txt”; Size: 39,896 bytes; and Date of Creation: December 29, 2020) is incorporated herein by reference in its entirety.

BACKGROUND

[0003] Phenylketonuria (PKU) is an autosomal recessive genetic disorder where the majority of cases are caused by mutations in the phenylalanine hydroxylase (PAH) gene. Mutations in the PAH gene result in a reduction or loss of PAH activity, an enzyme expressed in hepatocytes that catalyzes the hydroxylation of L-phenylalanine (Phe) to L-tyrosine (Tyr) upon multimerization. Reduction or loss of PAH activity leads to phenylalanine accumulation and its conversion into phenylpyruvate (also known as phenylketone). If left untreated, PAH deficiency results in progressive, irreversible neurological impairment during infancy and early childhood. The inability to achieve normal concentrations of Phe results in neurological as well as metabolic problems.

[0004] Currently, there is no cure for PKU. The standard of care is diet management by minimizing foods that contain high amounts of phenylalanine. Dietary management from birth with a low phenylalanine formula largely prevents the development of the intellectual disability of the disorder. However, even on a low-phenylalanine diet, children still suffer from growth retardation, and adults often have osteoporosis and vitamin deficiencies. Moreover, adherence to life-long dietary treatment is difficult, particularly once children reach school age. [0005] New treatment strategies have recently emerged, including large neutral amino acid (LNAA) supplementation, cofactor tetrahydrobiopterin therapy, enzyme replacement therapy, and genetically modified probiotic therapy. However, these strategies suffer from shortcomings. The LNAA supplementation is suitable only for adults not adhering to a low Phe diet. The cofactor tetrahydrobiopterin can only be used in some mild forms of PKU. Enzyme replacement by administration of a substitute for PAH, e.g., phenylalanine ammonia- lyase (PAL), can lead to immune responses that reduce the efficacy and/or cause side effects. As to genetically modified probiotic therapy, the pathogenicity of PAL-expressing E. coli has been a concern.

[0006] Gene therapy provides a unique opportunity to cure PKU. Retroviral vectors, including lentiviral vectors, are capable of integrating nucleic acids into host cell genomes, raising safety concerns due to their non-targeted insertion into the genome. For example, there is a risk of the vector disrupting a tumor suppressor gene or activating an oncogene, thereby causing a malignancy. Indeed, in a clinical trial for treating X-linked severe combined immunodeficiency (SCID) by transducing CD34 ⁺ bone marrow precursors with a gammaretroviral vector, four out of ten patients developed leukemia (Hacein-Bey-Abina et al. , J Clin Invest. (2008) 118(9): 3132-42). Non-integrating vectors, on the other hand, often suffer insufficient expression level or inadequate duration of expression in vivo.

[0007] Accordingly, there is a need in the art for improved gene therapy compositions and methods that can efficiently and safely restore PAH gene function in PKU patients.

SUMMARY

[0008] Provided herein are methods of treating a subject having a disease or disorder associated with a PAH gene mutation. The methods generally comprise administering to the subject a therapeutically effective dose of a recombinant adeno-associated virus (rAAV) that can express PAH polypeptide in a cell and thereby restore PAH gene function in the subject. [0009] Accordingly, in one aspect, the instant disclosure provides a method for treating a subject having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about 2el3 vg/kg, 3el3 vg/kg, 4el3 vg/kg, 5el3 vg/kg, 6el3 vg/kg, 7el3 vg/kg, 8el3 vg/kg, 9el3 vg/kg, lel4 vg/kg, 1.1 el 4 vg/kg, 1.2el4 vg/kg, 1.3el4 vg/kg, 1.4el4 vg/kg, 1.5el4 vg/kg, 1.6el4 vg/kg, 1.7el4 vg/kg, 1.8el4 vg/kg, 1.9el4 vg/kg, or 2el4 vg/kg {e.g., at a dose of 2el3 vg/kg, 3el3 vg/kg, 4el3 vg/kg, 5el3 vg/kg, 6el3 vg/kg, 7el3 vg/kg, 8el3 vg/kg, 9el3 vg/kg, lel4 vg/kg, 1. Iel4 vg/kg, 1.2el4 vg/kg, 1.3el4 vg/kg, 1.4el4 vg/kg, 1.5el4 vg/kg, 1.6el4 vg/kg, 1.7el4 vg/kg, 1.8el4 vg/kg, 1.9el4 vg/kg, or 2el4 vg/kg), wherein the rAAV comprises: (a) an AAV capsid comprising a capsid protein; and (b) a transfer genome comprising a silently altered PAH coding sequence, wherein the silently altered PAH coding sequence comprises the nucleotide sequence set forth in SEQ ID NO:l.

[0010] In certain embodiments, the transfer genome further comprises a transcriptional regulatory element operably linked to the silently altered PAH coding sequence. [0011] In certain embodiments, the transcriptional regulatory element is capable of mediating transcription in a hepatocyte, a renal cell, or a cell in the brain, pituitary gland, adrenal gland, pancreas, urinary bladder, gallbladder, colon, small intestine, or breast.

[0012] In certain embodiments, the transcriptional regulatory element comprises a human hepatic control region 1 (HCR1) comprising the nucleotide sequence set forth in SEQ ID NO:2. In certain embodiments, the transcriptional regulatory element comprises a human al -antitrypsin (hAAT) promoter comprising the nucleotide sequence set forth in SEQ ID NO:3. In certain embodiments, the transcriptional regulatory element comprises an SV40 intron comprising the nucleotide sequence set forth in SEQ ID NO: 4. In certain embodiments, the transcriptional regulatory element comprises the nucleotide sequence set forth in SEQ ID NO:5.

[0013] In certain embodiments, the transfer genome further comprises an SV40 polyadenylation sequence 3' to the PAH coding sequence, wherein the SV40 polyadenylation sequence comprises the nucleotide sequence set forth in SEQ ID NO:6.

[0014] In certain embodiments, the transfer genome comprises the nucleotide sequence set forth in SEQ ID NO: 7.

[0015] In certain embodiments, the transfer genome further comprises a 5' inverted terminal repeat (5' ITR) nucleotide sequence 5' of the genome, and a 3' inverted terminal repeat (3' ITR) nucleotide sequence 3' of the genome. In certain embodiments, the 5' ITR nucleotide sequence has at least 95% sequence identity to SEQ ID NO: 8, and the 3' ITR nucleotide sequence has at least 95% sequence identity to SEQ ID NO: 9.

[0016] In certain embodiments, the transfer genome comprises the nucleotide sequence set forth in SEQ ID NO: 10.

[0017] In certain embodiments, the AAV capsid comprises: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the ammo acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R.

[0018] In certain embodiments, the AAV capsid comprises: a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the ammo acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the ammo acid in the capsid protein corresponding to ammo acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R.

[0019] In certain embodiments, the AAV capsid comprises a capsid protein comprising the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, a capsid protein comprising the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, and/or a capsid protein comprising the amino acid sequence of amino acids 1 -736 of SEQ ID NO: 11.

[0020] In certain embodiments, the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11 , the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, and/or the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 1-736 of SEQ ID NO:ll.

[0021] In another aspect, the instant disclosure provides a method for treating a subj ect having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about 2el3 vg/kg, 3el3 vg/kg, 4el3 vg/kg, 5el3 vg/kg, 6el3 vg/kg, 7el3 vg/kg, 8el3 vg/kg, 9el3 vg/kg, lel4 vg/kg, l.lel4 vg/kg, 1.2el4 vg/kg, 1.3el4 vg/kg, 1.4el4 vg/kg, 1.5el4 vg kg, 1.6el4 vg/kg, 1.7el4 vg/kg, 1.8el4 vg/kg, 1.9el4 vg/kg, or2el4 vg/kg (e.g., at a dose of2el3 vg/kg, 3el3 vg/kg, 4el3 vg/kg, 5el3 vg/kg, 6el3 vg/kg, 7el3 vg/kg, 8el3 vg/kg, 9el3 vg/kg, lel4 vg/kg, l.lel4 vg/kg, 1.2el4 vg/kg, 1.3el4 vg/kg, 1.4el4 vg/kg, 1.5el4 vg/kg, 1.6el4 vg/kg, 1.7el4 vg/kg, 1.8el4 vg/kg, 1.9el4 vg/kg, or 2el4 vg/kg), wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11 , wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO:ll, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO:10.

[0022] In certain embodiments, the AAV capsid comprises: a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R.

[0023] In certain embodiments, the AAV capsid comprises: a capsid protein comprising the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11; a capsid protein comprising the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11 ; and/or a capsid protein comprising the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11. [0024] In certain embodiments, the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11; the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11; and/or the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 1-736 of SEQ ID NO:ll.

[0025] The following embodiments apply to each of the foregoing aspects.

[0026] In certain embodiments, the dose is about 2el3 vg/kg. In certain embodiments, the dose is about 6el3 vg/kg. In certain embodiments, the dose is about 8el3 vg/kg. In certain embodiments, the dose is about lel4 vg/kg. In certain embodiments, the dose is about 2el4 vg/kg.

[0027] In certain embodiments, the rAAV is administered as a single dose. In certain embodiments, the rAAV is administered as multiple doses. In certain embodiments, the rAAV is administered intravenously.

[0028] In certain embodiments, the subject is a pediatric subject. In certain embodiments, the subject is an adult subject.

[0029] In certain embodiments, the disease or disorder associated with a PAH gene mutation is phenylketonuria (PKU).

[0030] In another aspect, the present disclosure provides a method for treating a subj ect having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about 2el3 vg/kg, wherein the rAAV comprises:(a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO:l 1 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to ammo acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

[0031] In another aspect, the present disclosure provides a method for treating a subj ect having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about 6el3 vg/kg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO:l 1 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

[0032] In another aspect, the present disclosure provides a method for treating a subj ect having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about 8el3 vg/kg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO:l 1 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to ammo acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

[0033] In another aspect, the present disclosure provides a method for treating a subj ect having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about lei 4 vg/kg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO:l 1 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

[0034] In another aspect, the present disclosure provides a method for treating a subj ect having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about 2el4 vg/kg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO:l 1 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to ammo acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

[0035] The following embodiments apply to each of the foregoing aspects.

[0036] In certain embodiments, the subject is administered a first immunosuppressant prior to administration of the rAAV. In certain embodiments, the first immunosuppressant is administered one day prior to the administration of the rAAV. In certain embodiments, the first immunosuppressant is administered to the subject for about 20 or about 21 weeks.

[0037] In certain embodiments, the first immunosuppressant is administered according to the following sequential dosing regimen: (1) 60 mg/day in prednisolone equivalents for two weeks; (2) 40 mg/day in prednisolone equivalents for six weeks; (3) 30 mg/day in prednisolone equivalents for three weeks; (4) 20 mg/day in prednisolone equivalents for three weeks; (5) 10 mg/day in prednisolone equivalents for five weeks; and (6) 5 mg/day in prednisolone equivalents for one or two weeks.

[0038] In certain embodiments, if the subject exhibits a level of a liver transaminase that is at least about 2 times ULN at any time during the sequential dosing regimen, the sequential dosing regimen will be restarted from step (1).

[0039] In certain embodiments, if the subject exhibits a level of a liver transaminase that is at least about 2 times ULN after completion of step (6), the subject is further administered the first immunosuppressant according to the following sequential dosing regimen: (7) 60 mg/day in prednisolone equivalents for two to four weeks; (8) 40 mg/day in prednisolone equivalents for two weeks; (9) 30 mg/day in prednisolone equivalents for two weeks; (10) 20 mg/day in prednisolone equivalents for two weeks; (11) 10 mg/day in prednisolone equivalents for two weeks; and (12) 5 mg/day in prednisolone equivalents for two weeks. In certain embodiments, step (7) is performed until the level of the liver transaminase has declined to about or less than about the subject’s baseline level of the liver transaminase [0040] In certain embodiments, the subject’s baseline level of the liver transaminase is the level of the liver transaminase in the subject prior to receiving the rAAV. In certain embodiments, the subject’s baseline level of the liver transaminase is within a normal range. In certain embodiments, the subject’s baseline level of the liver transaminase is at about an upper limit of normal (ULN) for the liver transaminase. In certain embodiments, the liver transaminase is alanine aminotransferase (ALT) or aspartate aminotransferase (AST).

[0041] In certain embodiments, the normal range of ALT is from 0 to about 63 U/L. In certain embodiments, the normal range of AST is from 0 to about 57 U/L. In certain embodiments, the ULN for ALT is from about 30 to about 63 U/L. In certain embodiments, the ULN for AST is about 34 to about 57 U/L.

[0042] In certain embodiments, the first immunosuppressant is a glucocorticosteroid.

In certain embodiments, the first immunosuppressant is prednisolone.

BRIEF DESCRIPTION OF THE DRAWINGS [0043] Figure 1 is a vector map of the pHMI-hPAH-TC-025 vector.

[0044] Figures 2A-2B are graphs showing the levels of phenylalanine over time in the serum of male (Figure 2A) or female (Figure 2B) mice administered the indicated doses of an rAAV comprising the pHMI-hPAH-TC-025 vector.

[0045] Figures 3A-3D are graphs showing the levels of phenylalanine (Figures 3 A and

3C) or tyrosine (Figures 3B and 3D) in the serum of male (Figures 3A and 3B) or female (Figures 3C and 3D) mice administered with the indicated doses of an rAAV comprising the pHMI-hPAH-TC-025 vector.

[0046] Figure 4 is a schematic showing the design of an open-label, randomized, concurrently-controlled, dose escalation study of a single, ascending dose of a rAAV comprising the pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid, in adult subjects with PAH deficiency.

[0047] Figures 5A-5C show fasting Phe concentration (Figure 5A), fasting Tyr concentration (Figure 5B), and fasting Phe/Tyr ratio levels (Figure 5C) of three patients dosed with an rAAV comprising the HMI-hPAH-TC-025 vector packaged in AAVHSC15.

[0048] Figure 6 is a graph showing the level of plasma Phe over time for patient 1.

[0049] Figure 7 is a graph showing the level of plasma Phe over time for patient 2.

[0050] Figure 8 is a graph showing the level of plasma Phe over time for patient 3.

[0051] Figure 9 is a graph showing the level of plasma Phe over time for patient 4.

[0052] Figure 10 is a graph showing the level of plasma Phe over time for patient 5.

[0053] Figure 11 is a graph showing the level of plasma Phe over time for patient 6.

[0054] Figure 12 is a graph showing the level of plasma Phe over time, for patients 3 and 6.

[0055] Figure 13 is a graph showing the percent change from baseline of the level of plasma Phe over time, for patients of Cohort 1.

[0056] Figure 14 is a graph showing the percent change from baseline of the level of plasma Phe over time, for patients of Cohorts 2 and 3.

DETAILED DESCRIPTION [0057] Provided herein are methods of treating a subject having a disease or disorder associated with a PAH gene mutation. The methods generally comprise administering to the subject a therapeutically effective dose of a recombinant adeno-associated virus (rAAV) that can express a phenylalanine hydroxylase (PAH) polypeptide in a cell and thereby restore PAH gene function in the subject. I. Definitions

[0058] As used herein, the term "AAV" is a standard abbreviation for adeno-associated virus.

[0059] As used herein, the term “recombinant adeno-associated virus” or “rAAV” refers to an AAV comprising a genome lacking functional rep and cap genes.

[0060] As used herein, the term "cap gene" refers to a nucleic acid sequence that encodes a capsid protein.

[0061] As used herein, the term "rep gene" refers to the nucleic acid sequences that encode the non-structural proteins (e.g., rep78, rep68, rep52 and rep40) required for the replication and production of an AAV.

[0062] As used herein, the term “PAH gene” refers to the phenylalanine hydroxylase gene. The human PAH gene is identified by Entrez Gene ID 5053. An exemplary nucleotide sequence of a PAH mRNA is provided as SEQ ID NO: 12. An exemplary amino acid sequence of a PAH polypeptide is provided as SEQ ID NO: 13.

[0063] As used herein, the term “transfer genome” refers to a recombinant AAV genome comprising a coding sequence operably linked to an exogenous transcriptional regulatory element that mediates expression of the coding sequence when the transfer genome is introduced into a cell. In certain embodiments, the transfer genome does not integrate in the chromosomal DNA of the cell. The skilled artisan will appreciate that the portion of a transfer genome comprising the transcriptional regulatory element operably linked to a PAH coding sequence can be in the sense or antisense orientation relative to direction of transcription of the PAH coding sequence.

[0064] As used herein, the “percentage identity” between two nucleotide sequences or between two amino acid sequences is calculated by multiplying the number of matches between the pair of aligned sequences by 100, and dividing by the length of the aligned region, including internal gaps. Identity scoring only counts perfect matches, and does not consider the degree of similarity of amino acids to one another. Note that only internal gaps are included in the length, not gaps at the sequence ends.

[0065] As used herein, the term “a disease or disorder associated with a PAH gene mutation” refers to any disease or disorder caused by, exacerbated by, or genetically linked with mutation of a PAH gene. In certain embodiments, the disease or disorder associated with a PAH gene mutation is phenylketonuria (PKU). [0066] As used herein, the term “coding sequence” refers to the portion of a complementary DNA (cDNA) that encodes a polypeptide, starting at the start codon and ending at the stop codon. A gene may have one or more coding sequences due to alternative splicing, alternative translation initiation, and variation within the population. A coding sequence may either be wild-type or codon-altered. An exemplary wild-type PAH coding sequence is set forth in SEQ ID NO: 12.

[0067] As used herein, the term “silently altered” refers to alteration of a coding sequence or a stuffer-inserted coding sequence of a gene (e.g., by nucleotide substitution) without changing the amino acid sequence of the polypeptide encoded by the coding sequence or stuffer-inserted coding sequence. Such silent alteration is advantageous in that it may increase the translation efficiency of a coding sequence.

[0068] In the instant disclosure, nucleotide positions in a PAH gene are specified relative to the first nucleotide of the start codon. The first nucleotide of a start codon is position 1; the nucleotides 5' to the first nucleotide of the start codon have negative numbers; the nucleotides 3' to the first nucleotide of the start codon have positive numbers. An exemplary nucleotide 1 of the human PAH gene is nucleotide 5,473 of the NCBI Reference Sequence: NG_008690.1, and an exemplary nucleotide 3 of the human PAH gene is nucleotide 5,475 of the NCBI Reference Sequence: NG_008690.1. The nucleotide adjacently 5' to the start codon is nucleotide -1.

[0069] In the instant disclosure, exons and introns in a PAH gene are specified relative to the exon encompassing the first nucleotide of the start codon, which is nucleotide 5473 of the NCBI Reference Sequence: NG_008690.1. The exon encompassing the first nucleotide of the start codon is exon 1. Exons 3' to exon 1 are from 5' to 3': exon 2, exon 3, etc. Introns 3’ to exon 1 are from 5’ to 3’: intron 1, intron 2, etc. Accordingly, the PAH gene comprises from 5’ to 3’: exon 1, intron 1, exon 2, intron 2, exon 3, etc. An exemplary exon 1 of the human PAH gene is nucleotides 5001-5532 of the NCBI Reference Sequence: NG_008690.1. An exemplary intron 1 of the human PAH gene is nucleotides 5533-9704 of the NCBI Reference Sequence: NG_008690.1.

[0070] As used herein, the term “transcriptional regulatory element” or “TRE” refers to a cis-acting nucleotide sequence, for example, a DNA sequence, that regulates (e.g. , controls, increases, or reduces) transcription of an operably linked nucleotide sequence by an RNA polymerase to form an RNA molecule. A TRE relies on one or more trans-acting molecules, such as transcription factors, to regulate transcription. Thus, one TRE may regulate transcription in different ways when it is in contact with different trans-acting molecules, for example, when it is in different types of cells. A TRE may comprise one or more promoter elements and/or enhancer elements. A skilled artisan would appreciate that the promoter and enhancer elements in a gene may be close in location, and the term “promoter” may refer to a sequence comprising a promoter element and an enhancer element. Thus, the term “promoter” does not exclude an enhancer element in the sequence. The promoter and enhancer elements do not need to be derived from the same gene or species, and the sequence of each promoter or enhancer element may be either identical or substantially identical to the corresponding endogenous sequence in the genome.

[0071] As used herein, the term “operably linked” is used to describe the connection between a TRE and a coding sequence to be transcribed. Typically, gene expression is placed under the control of a TRE comprising one or more promoter and/or enhancer elements. The coding sequence is “operably linked” to the TRE if the transcription of the coding sequence is controlled or influenced by the TRE. The promoter and enhancer elements of the TRE may be in any orientation and/or distance from the coding sequence, as long as the desired transcriptional activity is obtained. In certain embodiments, the TRE is upstream from the coding sequence.

[0072] As used herein, the term “polyadenylation sequence” refers to a DNA sequence that when transcribed into RNA constitutes a polyadenylation signal sequence. The polyadenylation sequence can be native (e.g., from the PAH gene) or exogenous. The exogenous polyadenylation sequence can be a mammalian or a viral polyadenylation sequence (e.g., an SV40 polyadenylation sequence).

[0073] As used herein, “exogenous polyadenylation sequence” refers to a polyadenylation sequence not identical or substantially identical to the endogenous polyadenylation sequence of a PAH gene (e.g., human PAH gene). In certain embodiments, an exogenous polyadenylation sequence is a polyadenylation sequence of a non-PAH gene in the same species (e.g., human). In certain embodiments, an exogenous polyadenylation sequence is a polyadenylation sequence of a different species (e.g., a virus).

[0074] As used herein, the term “effective amount” in the context of the administration of an AAV to a subject refers to the amount of the AAV that achieves a desired prophylactic or therapeutic effect.

[0075] As used herein, the term “about” or “approximately” when referring to a measurable value, such as a dosage, encompasses variations of ±20% or ±10%, ±5%, ±1%, or ±0.1% of a given value or range, as are appropriate to perform the methods disclosed herein. [0076] As used herein in the context of the result of a liver function test (e g., the level of a liver transaminase in the blood of a subject), the term “normal range,” refers to a reference range expected for a healthy subject (i.e., a non-pathophysiological reference range). It is appreciated by those of skill in the art that a reference range varies between laboratory testing sites. As such, when determining whether a test value is within a normal range, the reference range supplied by the laboratory testing site that obtained the test value should be used. Further, it is known in the art that a reference range for a certain liver function test may be different for male and female sexes. Common liver function tests include determining the level of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphate (ALP), gamma-glutamyltransferase (GGT), bilirubin, and albumin. Liver function tests also include determining the prothrombin time (PT), which is a test that measures how long it takes blood to clot. In certain embodiments, the reference range for ALT is from 0 to about 45 IU/L, from about 3 to about 30 U/L, from about 1 to about 45 U/L, from about 17 to about 63 U/L, from about 14 to about 54 U/L. In certain embodiments, the reference range for AST is from 0 to about 35 IU/L, from about 2 to about 40 U/L, from about 1 to about 35 U/L, from about 18 to about 57 U/L, from about 5 to about 34 U/L, from about 15 to about 41 U/L. In certain embodiments, the reference range for ALP is from about 30 to about 120 IU/L, from about 38 to about 126 U/L, from about 69 to about 318 U/L, from about 53 to about 212 U/L, from about 34 to about 104 U/L. In certain embodiments, the reference range for direct bilirubin is from about 2 to about 17 pmol/L, from about 0 to about 0.4 mg/dL, from about 0 to about 0.8 mg/dL, from about 0 to about 0.3 mg/dL, from about 0 to about 0.2 mg/dL. In certain embodiments, the reference range for total bilirubin is from about 0.3 to about 1.2 mg/dL, from about 0.1 to about 1.2 mg/dL, from about 0.2 to about 1.2 mg/dL. In certain embodiments, the reference range for prothrombin time is from about 10.9 to about 12.5 seconds. In certain embodiments, the reference range for albumin is from about 40 to about 60 g/L.

[0077] As used herein in the context of the result of a liver function test (e.g., the level of a liver transaminase in the blood of a subject), “baseline value,” refers to a result of a liver function test that was obtained prior to the administration of a treatment described herein (e.g. , administration of a gene therapy to the subject). In certain embodiments, the baseline value for a liver function test is the result of the liver function test obtained from the subject prior to the administration of the gene therapy (e.g., a liver directed gene therapy). For example, the baseline value for ALT and/or AST is the value of ALT and/or AST obtained from the subject prior to the administration of a gene therapy. [0078] In certain embodiments, the result of a liver function test may be reported as a multiple of a certain reference value. For example, the result of a liver function test may be reported as a multiple of an upper limit of normal. As used herein, the term “upper limit of normal” or “ULN,” refers to the upper value of a reference range. For example, the ULN for ALT is the upper value of the reference range for ALT. In certain embodiments, the ULN for ALT is about 45 IU/L, about 30 U/L, about 45 U/L, about 63 U/L, about 54 U/L. In certain embodiments, the ULN for ALT is from about 30 U/L to about 63 U/L. In certain embodiments, the ULN for AST is about 35 IU/L, about 40 U/L, about 57 U/L, about 34 U/L, about 41 U/L. In certain embodiments, the ULN for AST is from about 34 U/L to about 57 U/L. In certain embodiments, the ULN for ALP is about 120 IU/L, about 126 U/L, about 318 U/L, about 212 U/L, about 104 U/L. In certain embodiments, the ULN for ALP is from about 104 U/L to about 318 U/L. In certain embodiments, the ULN for direct bilirubin is about 17 umol/L. about 0.4 mg/dL, about 0.8 mg/dL, about 0.3 mg/dL, about 0.2 mg/dL. In certain embodiments, the ULN for direct bilirubin is from about 0.2 mg/dL to about 0.8 mg/dL. In certain embodiments, the ULN for total bilirubin is about 1.2 mg/dL. In certain embodiments, the ULN for prothrombin time is about 12.5 seconds. In certain embodiments, the ULN for albumin is about 60 g/L. As such, the result of a liver function test may be reported as, e.g. , at least about 1.5 times the ULN, at least about 2 times the ULN, at least about 2.5 times the ULN, at least about 3 times the ULN, at least about 4 times the ULN, at least 5 times the ULN, at least 20 times the ULN, and the like.

[0079] An event such as elevated ALT can be described by a certain Grade. As used herein, the term “Grade” when used in the context of an event, refers to the Grade designation as provided by Common Terminology Criteria for Adverse Events (CTCAE). For example, the level of ALT elevation can be described as Grade 1 (greater than about 1 to about 3 times ULN if baseline was normal; greater than about 1.5 to about 3 times baseline if baseline was abnormal), Grade 2 (greater than about 3 to about 5 times ULN if baseline was normal; greater than about 3 to about 5 times baseline if baseline was abnormal), Grade 3 (greater than about 5 to about 20 times ULN if baseline was normal; greater than about 5 to about 20 times baseline if baseline was abnormal), and Grade 4 (greater than about 20 times ULN if baseline was normal; greater than about 20 times baseline if baseline was abnormal).

II. Recombinant Adeno-Associated Vims

[0080] The instant disclosure provides methods of treating a subject having a disease or disorder associated with a PAH gene mutation. The methods generally comprise administering to the subject a therapeutically effective does of a recombinant adeno-associated virus (rAAV) disclosed herein at a dose of about 2el3 vg/kg to about 2el4 kg/vg. rAAV suitable for use in these methods are described in detail below.

[0081] In certain embodiments, the rAAV employed in the methods disclosed herein disclosed comprise: an AAV capsid comprising a capsid protein; and a transfer genome comprising a transcriptional regulatoiy element operably linked to a PAH coding sequence (e.g., a silently altered PAH coding sequence), allowing for extrachromosomal expression of PAH in a cell transduced with the AAV.

[0082] In certain embodiments, the AAV capsid comprises one or more of: (a) a capsid protein comprising an amino acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to ammo acid 346 of SEQ ID NO: 11 is A, and wherein the ammo acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; (b) a capsid protein comprising an amino acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (c) a capsid protein comprising an amino acid sequence having at least 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity with the sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R.

[0083] In certain embodiments, the AAV capsid comprises one or more of: (a) a capsid protein comprising the ammo acid sequence of ammo acids 203-736 of SEQ ID NO:l 1; (b) a capsid protein comprising the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11; and (c) a capsid protein comprising the amino acid sequence of amino acids 1-736 of SEQ ID NO:ll.

[0084] In certain embodiments, the AAV capsid comprises two or more of: (a) a capsid protein comprising the amino acid sequence of amino acids 203-736 of SEQ ID NO:l 1; (b) a capsid protein comprising the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11; and (c) a capsid protein comprising the amino acid sequence of amino acids 1-736 of SEQ ID NO:ll.

[0085] In certain embodiments, the AAV capsid comprises: (a) a capsid protein having an amino acid sequence consisting of amino acids 203-736 of SEQ ID NO:ll; (b) a capsid protein having an amino acid sequence consisting of amino acids 138-736 of SEQ ID NO: 11 ; and (c) a capsid protein having an amino acid sequence consisting of amino acids 1-736 of SEQ ID NO: 11.

[0086] In certain embodiments, the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11; the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, and/or the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 1-736 of SEQ ID NO:ll.

[0087] Transfer genomes useful in the rAAV generally comprise a transcriptional regulatory element (TRE) operably linked to a PAH coding sequence. In certain embodiments, the transfer genome comprises a 5' inverted terminal repeat (5' ITR) nucleotide sequence 5' of the TRE and PAH coding sequence, and a 3' inverted terminal repeat (3' ITR) nucleotide sequence 3' of the TRE and PAH coding sequence.

[0088] In certain embodiments, the PAH coding sequence comprises all or substantially all of a coding sequence of a PAH gene. In certain embodiments, the transfer genome comprises anucleotide sequence encoding SEQ ID NO: 13 and can optionally further comprise an exogenous polyadenylation sequence 3' to the PAH coding sequence. In certain embodiments, the nucleotide sequence encoding SEQ ID NO: 13 is wild-type (e.g., having the sequence set forth in SEQ ID NO: 12). In certain embodiments, the nucleotide sequence encoding SEQ ID NO: 13 is codon-altered (e.g., having the sequence set forth in SEQ ID NO: 1).

[0089] In certain embodiments, the PAH coding sequence encodes a polypeptide comprising all or substantially all of the amino acids sequence of a PAH protein. In certain embodiments, the PAH coding sequence encodes the amino acid sequence of a wild-type PAH protein (e.g. , human PAH protein). In certain embodiments, the PAH coding sequence encodes the amino acid sequence of a mutant PAH protein (e.g. , human PAH protein), wherein the mutant PAH polypeptide is a functional equivalent of the wild-type PAH polypeptide, i.e., can function as a wild-type PAH polypeptide. In certain embodiments, the functionally equivalent PAH polypeptide further comprises at least one characteristic not found in the wild-type PAH polypeptide, e.g., the ability to stabilize PAH protein (e.g., dimer or tetramer), or the ability to resist protein degradation.

[0090] The transfer genome can be used to express PAH in any mammalian cells (e.g. , human cells). Thus, the TRE can be active in any mammalian cells (e.g., human cells). In certain embodiments, the TRE is active in a broad range of human cells. Such TREs may comprise constitutive promoter and/or enhancer elements including

[0091] Alternatively, the TRE may be a tissue-specific TRE, i.e., it is active in specific tissue(s) and/or organ(s). A tissue-specific TRE comprises one or more tissue-specific promoter and/or enhancer elements, and optionally one or more constitutive promoter and/or enhancer elements. A skilled artisan would appreciate that tissue-specific promoter and/or enhancer elements can be isolated from genes specifically expressed in the tissue by methods well known in the art. In certain embodiments, the TRE is liver-specific (e.g., hepatocyte- specific). Exemplary liver-specific TREs may comprise one or more elements including human APOE/C-I hepatic control region (HCR) 1 or 2 (e.g., comprising a nucleotide sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 2 or 14), and human SERPINA1 (hAAT) promoter (e.g., comprising a nucleotide sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical to SEQ ID NO: 3 or 15).

[0092] In certain embodiments, the transfer genome comprises two or more TREs, optionally comprising at least one of the TREs disclosed above. A skilled person in the art would appreciate that any of these TREs can be combined in any order, and combinations of a constitutive TRE and a tissue-specific TRE can drive efficient and tissue-specific transcription. [0093] Similarly, combinations of two or more tissue-specific TREs can drive efficient and tissue-specific transcription. For example, in certain embodiments, the transfer genome comprises a human HCR1 (e.g., comprising a nucleotide sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 2) and a hAAT promoter (e.g., comprising a nucleotide sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 3), optionally wherein the human HCR1 is 5' to the hAAT promoter. In certain embodiments, the transfer genome comprises a nucleotide sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to the sequence set forth in SEQ ID NO: 5. In certain embodiments, the transfer genome comprises a human HCR1 (e.g., comprising the nucleotide sequence set forth in SEQ ID NO: 2) and a hAAT promoter (e.g., comprising the nucleotide sequence set forth in SEQ ID NO: 3), optionally wherein the human HCR1 is 5' to the hAAT promoter. In certain embodiments, the transfer genome comprises the nucleotide sequence set forth in SEQ ID NO: 5.

[0094] In certain embodiments, the transfer vector further comprises an intron 5' to or inserted in the PAH coding sequence. Such introns can increase transgene expression, for example, by reducing transcriptional silencing and enhancing mRNA export from the nucleus to the cytoplasm. In certain embodiments, the transfer genome comprises from 5' to 3': a non coding exon, an intron, and the PAH coding sequence. In certain embodiments, an intron sequence is inserted in the PAH coding sequence, optionally wherein the intron is inserted at an intemucleotide bond that links two native exons. In certain embodiments, the intron is inserted at an intemucleotide bond that links native exon 1 and exon 2.

[0095] The intron can comprise a native intron sequence of the PAH gene, an intron sequence from a different species or a different gene from the same species, and/or a synthetic intron sequence. A skilled worker will appreciate that synthetic intron sequences can be designed to mediate RNA splicing by introducing any consensus splicing motifs known in the art (e.g., in Sibley et ak, (2016) Nature Reviews Genetics, 17, 407-21, which is incorporated by reference herein in its entirety). Exemplary intron sequences are provided in Lu et al. (2013) Molecular Therapy 21(5): 954-63, and Lu et al. (2017) Hum. Gene Ther. 28(1): 125-34, which are incorporated by reference herein in their entirety. In certain embodiments, the transfer genome comprises an SV40 intron (e.g., comprising a nucleotide sequence at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 4).

[0096] In certain embodiments, the transfer genome disclosed herein further comprises a transcription terminator (e.g., a polyadenylation sequence). In certain embodiments, the transcription terminator is 3' to the PAH coding sequence. The transcription terminator may be any sequence that effectively terminates transcription, and a skilled artisan would appreciate that such sequences can be isolated from any genes that are expressed in the cell in which transcription of the PAH coding sequence is desired. In certain embodiments, the transcription terminator comprises a polyadenylation sequence. In certain embodiments, the polyadenylation sequence is identical or substantially identical to the endogenous polyadenylation sequence of the human PAH gene. In certain embodiments, the polyadenylation sequence is an exogenous polyadenylation sequence. In certain embodiments, the polyadenylation sequence is an SV40 polyadenylation sequence (e.g., comprising the nucleotide sequence set forth in SEQ ID NO: 6, or a nucleotide sequence complementaiy thereto). In certain embodiments, the polyadenylation sequence comprises the sequence set forth in SEQ ID NO: 6. [0097] In certain embodiments, the transfer genome comprises from 5' to 3': a TRE, optionally a non-coding exon and an intron, a PAH coding sequence, and a polyadenylation sequence. In certain embodiments, the TRE has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to any one of SEQ ID NOs: 2, 3, and 5; the intron has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 4; the PAH coding sequence has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 1; and/or the polyadenylation sequence has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to any one of SEQ ID NOs: 6. In certain embodiments, the TRE comprises a nucleotide sequence selected from the group consisting of SEQ ID NOs: 2, 3, and 5; the intron comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 4; the PAH coding sequence comprises the sequence set forth in SEQ ID NO: 1; and/or the polyadenylation sequence comprises a nucleotide sequence selected from the group consisting of SEQ ID NOs: 6. In certain embodiments, the TRE comprises from 5' to 3' the sequence set forth in SEQ ID NO: 2, and the sequence set forth in SEQ ID NO: 3 (e.g., the TRE comprises the sequence set forth in SEQ ID NO: 5); the intron comprises the sequence set forth in SEQ ID NO: 4; the PAH coding sequence comprises the sequence set forth in SEQ ID NO: 1; and/or the polyadenylation sequence comprises the sequence set forth in SEQ ID NO: 6.

[0098] In certain embodiments, the transfer genome comprises a sequence at least 80%,

85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 7. In certain embodiments, the transfer genome comprises the nucleotide sequence set forth in SEQ ID NO: 7. In certain embodiments, the transfer genome consists of the nucleotide sequence set forth in SEQ ID NO: 7.

[0099] In certain embodiments, the transfer genomes disclosed herein further comprise a 5' inverted terminal repeat (5' ITR) nucleotide sequence 5' of the TRE, and a 3' inverted terminal repeat (3' ITR) nucleotide sequence 3' of the PAH coding sequence. ITR sequences from any AAV serotype or variant thereof can be used in the transfer genomes disclosed herein. The 5' and 3' ITR can be from an AAV of the same serotype or from AAVs of different serotypes. Exemplary ITRs for use in the transfer genomes disclosed herein are set forth in SEQ ID NOs: 8, 9, and 16-19 herein.

[00100] In certain embodiments, the 5' ITR or 3' ITR is from AAV2. In certain embodiments, both the 5' ITR and the 3' ITR are from AAV2. In certain embodiments, the 5' ITR nucleotide sequence has at least 90% (e.g., at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) sequence identity to SEQ ID NO: 16, or the 3' ITR nucleotide sequence has at least 90% (e.g., at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) sequence identity to SEQ ID NO: 17. In certain embodiments, the 5' ITR nucleotide sequence has at least 90% (e.g., at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) sequence identity to SEQ ID NO: 16, and the 3' ITR nucleotide sequence has at least 90% (e.g., at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) sequence identity to SEQ ID NO: 17. In certain embodiments, the transfer genome comprises a nucleotide sequence set forth in any one of SEQ ID NOs: 7, a 5' ITR nucleotide sequence having the sequence of SEQ ID NO: 16, and a 3' ITR nucleotide sequence having the sequence of SEQ ID NO: 17.

[00101] In certain embodiments, the 5' ITR or 3’ ITR are from AAV5. In certain embodiments, both the 5’ ITR and 3’ ITR are from AAV5. In certain embodiments, the 5’ ITR nucleotide sequence has at least 90% (e.g., at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) sequence identity to SEQ ID NO: 18, or the 3' ITR nucleotide sequence has at least 90% (e.g., at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) sequence identity to SEQ ID NO: 19. In certain embodiments, the 5' ITR nucleotide sequence has at least 90% (e.g., at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) sequence identity to SEQ ID NO: 18, and the 3' ITR nucleotide sequence has at least 90% (e.g., at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100%) sequence identity to SEQ ID NO: 19. In certain embodiments, the transfer genome comprises a nucleotide sequence set forth in any one of SEQ ID NOs: 7, a 5' ITR nucleotide sequence having the sequence of SEQ ID NO: 18, and a 3' ITR nucleotide sequence having the sequence of SEQ ID NO: 19.

[00102] In certain embodiments, the 5' ITR nucleotide sequence and the 3' ITR nucleotide sequence are substantially complementary to each other (e.g., are complementary to each other except for mismatch at 1, 2, 3, 4, or 5 nucleotide positions in the 5' or 3' ITR). [00103] In certain embodiments, the 5' ITR or the 3' ITR is modified to reduce or abolish resolution by Rep protein ("non-resolvable ITR"). In certain embodiments, the non-resolvable ITR comprises an insertion, deletion, or substitution in the nucleotide sequence of the terminal resolution site. Such modification allows formation of a self-complementary, double-stranded DNA genome of the AAV after the transfer genome is replicated in an infected cell. Exemplary non-resolvable ITR sequences are known in the art (see e.g., those provided in U.S. Patent Nos. 7,790,154 and 9,783,824, which are incorporated by reference herein in their entirety). In certain embodiments, the 5’ ITR comprises a nucleotide sequence at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 8. In certain embodiments, the 5’ ITR consists of a nucleotide sequence at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 8. In certain embodiments, the 5' ITR consists of the nucleotide sequence set forth in SEQ ID NO:

8. In certain embodiments, the 3' ITR comprises a nucleotide sequence at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 9. In certain embodiments, the 5' ITR consists of a nucleotide sequence at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 9. In certain embodiments, the 3' ITR consists of the nucleotide sequence set forth in SEQ ID NO:

9. In certain embodiments, the 5' ITR consists of the nucleotide sequence set forth in SEQ ID NO: 8, and the 3' ITR consists of the nucleotide sequence set forth in SEQ ID NO: 9. In certain embodiments, the 5' ITR consists of the nucleotide sequence set forth in SEQ ID NO: 8, and the 3' ITR consists of the nucleotide sequence set forth in SEQ ID NO: 17.

[00104] In certain embodiments, the 3’ ITR is flanked by an additional nucleotide sequence derived from a wild-type AAV2 genomic sequence. In certain embodiments, the 3’ ITR is flanked by an additional 37 bp sequence derived from a wild-type AAY2 sequence that is adjacent to a wild-type AAV2 ITR. See, e.g., Savy et al, Human Gene Therapy Methods (2017) 28(5): 277-289 (which is hereby incorporated by reference herein in its entirety). In certain embodiments, the additional 37 bp sequence is internal to the 3’ ITR. In certain embodiments, the 37 bp sequence consists of the sequence set forth in SEQ ID NO: 20. In certain embodiments, the 3’ ITR comprises a nucleotide sequence at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 21. In certain embodiments, the 3’ ITR comprises the nucleotide sequence set forth in SEQ ID NO: 21. In certain embodiments, the nucleotide sequence of the 3’ ITR consists of a nucleotide sequence at least 95%, 96%, 97%, 98%, or 99% identical to SEQ ID NO: 21. In certain embodiments, the nucleotide sequence of the 3’ ITR consists of the nucleotide sequence set forth in SEQ ID NO: 21.

[00105] In certain embodiments, the transfer genome comprises from 5' to 3': a 5' ITR; an internal element comprising from 5’ to 3’: a TRE, optionally a non-coding exon and an intron, a PAH coding sequence, and a polyadenylation sequence, as disclosed herein; a non- resolvable ITR; a nucleotide sequence complementary to the internal element; and a 3’ ITR. Such transfer genome can form a self-complementary, double-stranded DNA genome of the AAY after infection and before replication.

[00106] In certain embodiments, the transfer genome comprises from 5' to 3': a 5' ITR, a TRE, optionally a non-coding exon and an intron, a PAH coding sequence, a polyadenylation sequence, and a 3' ITR. In certain embodiments, the 5' ITR has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 8, 16, or 18; the TRE has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to any one of SEQ ID NO: 2, 3, or 5; the intron has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 4; the PAH coding sequence has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 1; the polyadenylation sequence has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to any one of SEQ ID NO: 6; and/or the 3' ITR has at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99% sequence identity to SEQ ID NO: 9, 17, or 19. In certain embodiments, the 5' ITR comprises or consists of anucleotide sequence selected from the group consisting of SEQ ID NOs: 8, 16, or 18; the TRE comprises a nucleotide sequence selected from the group consisting of SEQ ID NOs: 2, 3, or 5; the intron comprises a nucleotide sequence selected from the group consisting of SEQ ID NOs: 4; the PAH coding sequence comprises the sequence set forth in SEQ ID NO: 1; the polyadenylation sequence comprises a nucleotide sequence selected from the group consisting of SEQ ID NO: 6; and or the 3' ITR comprises or consists of a nucleotide sequence selected from the group consisting of SEQ ID NOs: 9, 17, or 19. In certain embodiments, the 5' ITR comprises or consists of the sequence set forth in SEQ ID NO: 8; the TRE comprises from 5' to 3' the sequence set forth in SEQ ID NO: 2, and the sequence set forth in SEQ ID NO: 3 (e.g., the TRE comprises the sequence set forth in SEQ ID NO: 5); the intron comprises the sequence set forth in SEQ ID NO: 4; the PAH coding sequence comprises the sequence set forth in SEQ ID NO: 1; the polyadenylation sequence comprises the sequence set forth in SEQ ID NO: 6 and/or the 3' ITR comprises or consists of the sequence set forth in SEQ ID NO: 9.

[00107] In certain embodiments, the transfer genome comprises a sequence at least 80% (e.g., at least 85%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, or 99%) identical to the sequence set forth in SEQ ID NO: 10. In certain embodiments, the transfer genome comprises the sequence set forth in SEQ ID NO: 10. In certain embodiments, the transfer genome consists of the sequence set forth in SEQ ID NO: 10.

[00108] In certain embodiments, the rAAV comprises: (a) an AAV capsid protein comprising the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, and a transfer genome comprising 5' to 3' following genetic elements: a 5' ITR element (e.g., the 5' ITR of SEQ ID NO: 8), a human HCR1 (e.g., the HCR1 of SEQ ID NO: 2), an hAAT promoter (e.g., the hAAT promoter of SEQ ID NO: 3), an SV40 intron (e.g., the SV40 intron of SEQ ID NO: 4), a silently altered human PAH coding sequence (e.g., the PAH coding sequence of SEQ ID NO: 1), an SV40 polyadenylation sequence (e.g., the SV40 polyadenylation sequence of SEQ ID NO: 6), and a 3' ITR element (e.g. , the 3' ITR of SEQ ID NO: 9); (b) an AAV capsid protein comprising the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, and a transfer genome comprising 5' to 3' following genetic elements: a 5' ITR element ( e.g ., the 5' ITR of SEQ ID NO: 8), a human HCR1 (e.g., the HCR1 of SEQ ID NO: 2), an hAAT promoter (e.g., the hAAT promoter of SEQ ID NO: 3), an SV40 intron (e.g., the SV40 intron of SEQ ID NO: 4), a silently altered human PAH coding sequence (e.g., the PAH coding sequence of SEQ ID NO: 1), an SV40 polyadenylation sequence (e.g., the SV40 polyadenylation sequence of SEQ ID NO: 6), and a 3' ITR element (e.g. , the 3' ITR of SEQ ID NO: 9); and/or (c) an AAV capsid protein comprising the amino acid sequence of SEQ ID NO: 11, and a transfer genome comprising 5' to 3' following genetic elements: a 5' ITR element (e.g., the 5' ITR of SEQ ID NO: 8), a human HCR1 (e.g., the HCR1 ofSEQ ID NO: 2), an hAAT promoter (e.g., the hAAT promoter of SEQ ID NO: 3), an SV40 intron (e.g. , the SV40 intron of SEQ ID NO: 4), a silently altered human PAH coding sequence (e.g., the PAH coding sequence of SEQ ID NO: 1), an SV40 polyadenylation sequence (e.g., the SV40 polyadenylation sequence of SEQ ID NO: 6), and a 3' ITR element (e.g, the 3' ITR of SEQ ID NO: 9).

[00109] In certain embodiments, the rAAV comprises: (a) an AAV capsid protein comprising the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, and a transfer genome comprising the nucleotide sequence set forth in any one of SEQ ID NOs: 7 or 10; (b) an AAV capsid protein comprising the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, and a transfer genome comprising the nucleotide sequence set forth in any one of SEQ ID NOs: 7 or 10; and/or (c) an AAV capsid protein comprising the amino acid sequence of SEQ ID NO: 11, and a transfer genome comprising the nucleotide sequence set forth in any one of SEQ ID NOs: 7 or 10.

[00110] In certain embodiments, the rAAV are present in pharmaceutical compositions comprising an rAAV as disclosed herein together with a pharmaceutically acceptable excipient, adjuvant, diluent, vehicle or carrier, or a combination thereof. A “pharmaceutically acceptable carrier” includes any material which, when combined with an active ingredient of a composition, allows the ingredient to retain biological activity and without causing disruptive physiological reactions, such as an unintended immune reaction. Pharmaceutically acceptable carriers include water, phosphate buffered saline, emulsions such as oil/water emulsion, and wetting agents. Compositions comprising such carriers are formulated by well-known conventional methods such as those set forth in Remington’s Pharmaceutical Sciences, current Ed., Mack Publishing Co., Easton Pa. 18042, USA; A. Gennaro (2000) “Remington: The Science and Practice of Pharmacy”, 20th edition, Lippincott, Williams, & Wilkins; Pharmaceutical Dosage Forms and Drug Delivery Systems (1999) H. C. Ansel et al, 7th ed., Lippincott, Williams, & Wilkins; and Handbook of Pharmaceutical Excipients (2000) A. H. Kibbe et al, 3rd ed. Amer. Pharmaceutical Assoc.

[00111] In certain embodiments, relative amounts vary of the active ingredient (e.g., rAAV), a pharmaceutically acceptable excipient, and/or any other ingredients. In certain embodiments, the relative amounts may depend upon various factors, including, without limitation, the subject’s size (e.g., weight) and the subject’s overall health. In certain embodiments, a pharmaceutical composition of the present disclosure contains from about 0.1% to about 100% (w/w) of the active ingredient. For example, a pharmaceutical composition of the present disclosure comprises from about 0.1% to about 10.0% (w/w), from about 5.0% to about 15.0% (w/w), from about 10.0% to about 20.0% (w/w), from about 15.0% to about 25.0% (w/w), from about 20.0% to about 30.0% (w/w), from about 25.0% to about 35.0% (w/w), from about 30.0% to about 40.0% (w/w), from about 35.0% to about 45.0% (w/w), from about 40.0% to about 50.0% (w/w), from about 45.0% to about 55.0% (w/w), from about 50.0% to about 60.0% (w/w), from about 55.0% to about 65.0% (w/w), from about 60.0% to about 70.0% (w/w), from about 65.0% to about 75.0% (w/w), from about 70.0% to about 80.0% (w/w), from about 75.0% to about 85.0% (w/w), from about 80.0% to about 90.0% (w/w), from about 85.0% to about 95.0%, from about 90.0% to about 100.0% (w/w), or relative amount in between.

[00112] In certain embodiments, the pharmaceutical compositions are suitable for administration to a subject in need thereof (e.g., a subject having a disease or disorder associated with PAH deficiency). The subject in need can be any animal. For example, the animal may be a mammal, such as a primate (e.g., human or monkey) or a non-primate (e.g., mouse, rat, cat, dog, cow, pig, or horse, etc.). For example, the subject can be a non-mammal, e.g., chicken or duck, etc. Those of skill in the art will be able to determine routine modifications to the formulation or pharmaceutical composition to render it suitable for administration to various animals. In certain embodiments, and pharmaceutical compositions provided herein are suitable for administration to a human subject.

[00113] In certain embodiments, pharmaceutical compositions can be prepared by any method known by those of skill in the art. pharmaceutical compositions may include, without limitation, salts, buffers, carbohydrates, sugars, proteins, peptides, and other components known in the art.

III. Methods of Use [00114] The instant disclosure provides methods of treating a subject having a disease or disorder associated with a PAH gene mutation. The methods generally comprise administering to the subject a recombinant adeno-associated virus (rAAV) disclosed herein at a dose of about 2el3 vg/kg to about 2el4 kg/vg.

[00115] The methods disclosed herein can be applied to any cell harboring a mutation in the PAH gene. The skilled worker will appreciate that cells that are active in Phe metabolism are of particular interest. Accordingly, in certain embodiments, the methods are applied to cells in the liver, kidney, brain, pituitary gland, adrenal gland, pancreas, urinary bladder, gallbladder, colon, small intestine, or breast. In certain embodiments, the method is applied to hepatocytes and/or renal cells.

[00116] In certain embodiments, the cell to be transduced is in a mammalian subject and the AAV is administered to the subject in an amount effective to transduce the cell in the subject. Accordingly, in certain embodiments, the instant disclosure provides a method for treating a subject having a disease or disorder associated with a PAH gene mutation, the method generally comprising administering to the subject an effective amount of an rAAV as disclosed herein. The subj ect can be a human subj ect, a non-human primate subj ect (e.g. , a cynomolgus), or a rodent subject (e.g., a mouse) with a PAH mutation, or anon-human primate subject (e.g., a cynomolgus) or a rodent subject (e.g., a mouse) containing PAH -mutant human liver cells. Suitable mouse subjects include without limitation, mice into which human liver cells (e.g., human hepatocytes) have been engrafted. Any disease or disorder associated with a PAH gene mutation can be treated using the methods disclosed herein. Suitable diseases or disorders include, without limitation, phenylketonuria.

[00117] In certain embodiments, the foregoing methods employ an rAAV comprising: (a) an AAV capsid protein comprising the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, and a transfer genome comprising 5' to 3' following genetic elements: a 5' ITR element (e.g., the 5' ITR of SEQ ID NO: 8), a human HCR1 (e.g., the HCR1 of SEQ ID NO: 2), an hAAT promoter (e.g., the hAAT promoter of SEQ ID NO: 3), an SV40 intron (e.g., the SV40 intron of SEQ ID NO: 4), a silently altered human PAH coding sequence (e.g. , the PAH coding sequence of SEQ ID NO: 1), an SV40 polyadenylation sequence (e.g., the SV40 polyadenylation sequence of SEQ ID NO: 6), and a 3' ITR element (e.g., the 3' ITR of SEQ ID NO: 9); (b) an AAV capsid protein comprising the amino acid sequence of amino acids 138- 736 of SEQ ID NO: 11, and a transfer genome comprising 5' to 3' following genetic elements: a 5' ITR element (e.g., the 5' ITR of SEQ ID NO: 8), a human HCR1 (e.g., the HCR1 of SEQ ID NO: 2), an hAAT promoter (e.g., the hAAT promoter of SEQ ID NO: 3), an SV40 intron (e.g., the SV40 intron of SEQ ID NO: 4), a silently altered human PAH coding sequence (e.g., the PAH coding sequence of SEQ ID NO: 1), an SV40 polyadenylation sequence (e.g., the SV40 polyadenylation sequence of SEQ ID NO: 6), and a 3' ITR element (e.g., the 3' ITR of SEQ ID NO: 9); and/or (c) an AAV capsid protein comprising the amino acid sequence of SEQ ID NO: 11, and a transfer genome comprising 5' to 3' following genetic elements: a 5' ITR element (e.g., the 5' ITR of SEQ ID NO: 8), a human HCR1 (e.g., the HCR1 of SEQ ID NO: 2), an hAAT promoter (e.g., the hAAT promoter of SEQ ID NO: 3), an SV40 intron (e.g., the SV40 intron of SEQ ID NO: 4), a silently altered human PAH coding sequence (e.g. , the PAH coding sequence of SEQ ID NO: 1), an SV40 polyadenylation sequence (e.g., the SV40 polyadenylation sequence of SEQ ID NO: 6), and a 3' ITR element (e.g., the 3’ ITR of SEQ ID NO: 9).

[00118] In certain embodiments, the foregoing methods employ an rAAV comprising: (a) an AAV capsid protein comprising the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, and a transfer genome comprising the nucleotide sequence set forth in any one of SEQ ID NOs: 7 or 10; (b) an AAV capsid protein comprising the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, and a transfer genome comprising the nucleotide sequence set forth in any one of SEQ ID NOs: 7 or 10; and/or (c) an AAV capsid protein comprising the amino acid sequence of SEQ ID NO: 11, and a transfer genome comprising the nucleotide sequence set forth in any one of SEQ ID NOs: 7 or 10.

[00119] The methods disclosed herein are particularly advantageous in that they are capable of expressing a PAH protein in a cell with high efficiency both in vivo and in vitro. In certain embodiments, the expression level of the PAH protein is at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% of the expression level of the endogenous PAH protein in a cell of the same type that does not have a mutation in the PAH gene. In certain embodiments, the expression level of the PAH protein is at least 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 3, 4, 5, 6, 7, 8, 9, or 10 fold higher than the expression level of the endogenous PAH protein in a cell of the same type that does not have a mutation in the PAH gene. Any methods of determining the expression level of the PAH protein can be employed including, without limitation, ELISA, Western blotting, immunostaining, and mass spectrometry.

[00120] In certain embodiments, transduction of a cell with an AAV composition disclosed herein can be performed as provided herein or by any method of transduction known to one of ordinary skill in the art. In certain embodiments, the cell may be contacted with the AAV at a multiplicity of infection (MOI) of 50,000; 100,000; 150,000; 200,000; 250,000; 300,000; 350,000; 400,000; 450,000; or 500,000, or at any MOI that provides for optimal transduction of the cell.

[00121] An AAV composition disclosed herein can be administered to a subject by any appropriate route including, without limitation, intravenous, intraperitoneal, subcutaneous, intramuscular, intranasal, topical or intradermal routes. In certain embodiments, the composition is formulated for administration via intravenous injection or subcutaneous injection.

[00122] In another aspect, the instant disclosure provides methods of administering the rAAV as disclosed herein to a subject in need thereof. Any route of administration for delivering the rAAV to the subj ect effective for preventing, managing, treating, or diagnosing a disease or disorder associated with a PAH gene mutation can be used. Any effective amount of rAAV can be delivered to the subject effective for preventing, managing, treating, or diagnosing a disease or disorder associated with a PAH gene mutation. It is understood by those of skill in the art that the appropriate amount and route of administration of the rAAV may be decided by the attending medical professional (e g., physician). Specific amounts of rAAV to be administered may depend on various factors, including without limitation, the age, sex, body weight, and general health of the subject, as well as other factors known to those of skill in the art.

[00123] In certain embodiments, the rAAV is administered as multiple doses. In certain embodiments, the rAAV is administered as one or more doses as part of a multiple dosage regime. In certain embodiments, the rAAV is administered as two, three, four, five, six, seven, eight, nine, ten, or more doses. In certain embodiments, the one or more doses make up a total dose that is sufficient to elicit a pharmaceutical effect (e.g., alleviate one or more symptoms of PKU).

[00124] In certain embodiments, the one or more doses are administered via a single route of administration (e.g., intravenously). In certain embodiments, the one or more doses are administered via multiple routes of administration. In certain embodiments, the one or more doses are administered via one, two, three, four, five, six, or more routes of administration.

[00125] In certain embodiments, the rAAV is administered as a single dose. In certain embodiments, the rAAV is administered at a dose of about 2el3 vg/kg to about 2el4 vg/kg (i.e., at about 2xl0 ¹³ vg/kg to about 2xl0 ¹⁴ vg/kg), wherein vg represents the number of viral genomes. In certain embodiments, the rAAV is administered at a dose of about lel3 vg/kg to about 3el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about le!3 vg/kg to about 3el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2el3 vg/kg to about 4el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 3el3 vg/kg to about 5el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 4el3 vg/kg to about 6el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 5el3 vg/kg to about 7el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 6el3 vg/kg to about 8el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 7el3 vg/kg to about 9el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 8el3 vg/kg to about lel4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 9el3 vg/kg to about 1.21el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about lel4 vg/kg to about 1.2el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 1.1 el 4 vg/kg to about 1.3el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 1.2el4 vg/kg to about 1.4el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 1.3el4 vg/kg to about 1.5el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 1.4el4 vg/kg to about 1 6el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 1.5el4 vg/kg to about 1.7el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 1.6el4 vg/kg to about 1.8el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 1.7el4 vg/kg to about 1.9el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 1.8el4 vg/kg to about 2el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 1.9el4 vg/kg to about 2.1el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2el4 vg/kg to about 2.2el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2. Iel4 vg/kg to about 2.3el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2.2el4 vg/kg to about 2.4el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2.3el4 vg/kg to about 2.5el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2.4el4 vg/kg to about 2.6el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2.5el4 vg/kg to about 2.7el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2.6el4 vg/kg to about 2.8el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2.7el4 vg/kg to about 2.9el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2.8el4 vg/kg to about 3el4 vg/kg. [00126] In certain embodiments, the rAAV is administered at a dose of about 2el3 vg/kg, 3el3 vg/kg, 4el3 vg/kg, 5el3 vg/kg, 6el3 vg/kg, 7el3 vg/kg, 8el3 vg/kg, 9el3 vg/kg, le!4 vg/kg, l.lel4 vg/kg, 1.2el4 vg/kg, 1.3el4 vg/kg, 1.4el4 vg/kg, 1.5el4 vg/kg, 1.6el4 vg/kg, 1.7el4 vg/kg, 1.8el4 vg/kg, 1.9el4 vg/kg, or 2el4 vg/kg. In certain embodiments, the rAAV is administered atadose of2el3 vg/kg, 3el3 vg/kg, 4el3 vg/kg, 5el3 vg/kg, 6el3 vg/kg, 7el3 vg/kg, 8el3 vg/kg, 9el3 vg/kg, lel4 vg/kg, l.lel4 vg/kg, 1.2el4 vg/kg, 1.3el4 vg/kg, 1.4el4 vg/kg, 1.5el4 vg/kg, 1.6el4 vg/kg, 1.7el4 vg/kg, 1.8el4 vg/kg, 1.9el4 vg/kg, or 2el4 vg/kg.

[00127] In certain embodiments, the rAAV is administered at a dose of about 9el2 vg/kg, about 9.5el2 vg/kg, about lel3 vg/kg, about 1.5el3 vg/kg, about 2el3 vg/kg, about 2.5el3 vg/kg, about 3el3 vg/kg, about 3.5el3 vg/kg, about 4el3 vg/kg, about 4.5el3 vg/kg, about 5el3 vg/kg, about 5.5el3 vg/kg, about 6el3 vg/kg, about 6.5el3 vg/kg, about 7el3 vg/kg, about 7.5el3 vg/kg, about 8el3 vg/kg, about 8.5el3 vg/kg, about 9el3 vg/kg, about 9.5el3 vg/kg, about lel4 vg/kg, about 1.5el4 vg/kg, about 2el4 vg/kg, or about 2.5el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about lel3 vg/kg, about 1.2el3 vg/kg, about 1.4el3 vg/kg, about 1.6el3 vg/kg, about 1.8el3 vg/kg, about 2el3 vg/kg, about 2.2el3 vg/kg, about 2.4el3 vg/kg, about 2.6el3 vg/kg, about 2.8el3 vg/kg, or about 3el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 6el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 5el3 vg/kg, about 5.2el3 vg/kg, about 5.4el3 vg/kg, about 5.6el3 vg/kg, about 5.8el3 vg/kg, about 6el3 vg/kg, about 6.2el3 vg/kg, about 6.4el3 vg/kg, about 6.6el3 vg/kg, about 6.8el3 vg/kg, or about 7el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 8el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 7el3 vg/kg, about 7.2el3 vg/kg, about 7.4el3 vg/kg, about 7.6el3 vg/kg, about 7.8el3 vg/kg, about 8el3 vg/kg, about 8.2el3 vg/kg, about 8.4el3 vg/kg, about 8.6el3 vg/kg, about 8.8el3 vg/kg, or about 9el3 vg/kg. In certain embodiments, the rAAV is administered at a dose of about lel4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 9el3 vg/kg, about 9.2el3 vg/kg, about 9.4el3 vg/kg, about 9.6el3 vg/kg, about 9.8el3 vg/kg, about lel4 vg/kg, about 1.2el4 vg/kg, about 1.4el4 vg/kg, about 1.6el4 vg/kg, about 1.8el4 vg/kg, or about 2el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about 2el4 vg/kg. In certain embodiments, the rAAV is administered at a dose of about lel4 vg/kg, about 1.2el4 vg/kg, about 1.4el4 vg/kg, about 1.6el4 vg/kg, about 1.8el4 vg/kg, about 2el4 vg/kg, about 2.2el4 vg/kg, about 2.4el4 vg/kg, about 2.6el4 vg/kg, about 2.8el4 vg/kg, or about 3el4 vg/kg. [00128] In certain embodiments, administration of the rAAV as described herein to a subject in need thereof, results in minimal incidences of adverse events. In certain embodiments, administration of the rAAV to a subject in need thereof, results in minimal incidences of serious adverse events. In certain embodiments, the adverse events may be a result of the administration of the rAAV. Accordingly, in certain embodiments, administration of the rAAV to a subj ect in need thereof, results in minimal incidences of adverse events and/or serious adverse events that may be a result of the administration of the rAAV. In certain embodiments, administration of the rAAV to a subject in need thereof, results in a reduction of the incidence and severity of treatment emergent adverse events (TEAEs) and serious TEAEs. [00129] In certain embodiments, administration of the rAAV as described herein to a subject in need thereof, alleviates one or more symptoms related to phenylketonuria (PKU). Symptoms of PKU may include, without limitation, a musty odor in the breath, skin, or urine; neurological symptoms that may include seizures; skin rashes ( e.g . , eczema); fair skin and blue eyes; abnormally small head (i.e., microencephaly); hyperactivity; intellectual disability; delayed development; behavioral, emotional, and social problems; and psychiatric disorders. Accordingly, in certain embodiments, administration of the rAAV as described herein to a subject in need thereof, alleviates one or more symptoms of PKU selected from the group consisting of a musty odor in the breath, skin, or urine; neurological symptoms that may include seizures; skin rashes (e.g., eczema); fair skin and blue eyes; abnormally small head (i.e., microencephaly); hyperactivity; intellectual disability; delayed development; behavioral, emotional, and social problems; and psychiatric disorders.

[00130] In certain embodiments, the normal range of blood phenylalanine (Phe) (e.g., plasma Phe) for a subj ect without hyperpheny lalanemia (HP A; e.g. , a subj ect that does not have a disease or disorder associated with a PAH gene mutation) is 58±14 pmol/L. In certain embodiments, a subject having a disease or disorder associated with a PAH gene mutation (e.g. , PAH deficiency) that does not require treatment according to standard treatment guidelines available in the art, has a range of blood Phe (e.g., plasma Phe) between about 120 pmol/L to about 360 pmol/L (e.g. , a blood Phe (e.g. , plasma Phe) of about 100 pmol/L, about 110 pmol/L, about 120 pmol/L, about 130 pmol/L, about 140 pmol/L, about 150 pmol/L, about 160 pmol/L, about 170 pmol/L, about 180 pmol/L, about 190 pmol/L, about 200 pmol/L, about 210 pmol/L, about 220 pmol/L, about 230 pmol/L, about 240 pmol/L, about 250 pmol/L, about 260 pmol/L, about 270 pmol/L, about 280 pmol/L, about 290 pmol/L, about 300 pmol/L, about 310 pmol/L, about 320 pmol/L, about 330 pmol/L, about 340 pmol/L, about 350 pmol/L, about 360 pmol/L, about 370 pmol/L, about 380 pmol/L, about 390 pmol/L, or about 400 pmol/L. In certain embodiments, a subject having PAH deficiency (e.g., PKU) that does not require treatment according to standard treatment guidelines available in the art, has a range of blood Phe (e.g., plasma Phe) between about 120 pmol/L to about 360 pmol/L. In certain embodiments, a subject having PKU that does not require treatment according to standard treatment guidelines available in the art, has a range of blood Phe (e.g., plasma Phe) between about 120 pmol/L to about 360 pmol/L.

[00131] In certain embodiments, a subject having a disease or disorder associated with a PAH gene mutation (e.g. hyperphenylalanemia, PKU) suitable for treatment with an rAAV of the present disclosure has a blood Phe (e.g., plasma Phe) of greater than about 600 pmol/L. In certain embodiments, a suitable subject for treatment with an rAAV of the present disclosure has had two plasma Phe values with a concentration >600 pmol/L drawn at least 48 hours apart, and at least one historical value >600 pmol/L in the preceding 12 months. In certain embodiments, a subject having a disease or disorder associated with a PAH gene mutation (e.g. hyperphenylalanemia, PKU) suitable for treatment with an rAAV of the present disclosure has a blood Phe (e.g., plasma Phe) of greater than about 450 pmol/L, greater than about 500 pmol/L, greater than about 450 pmol/L, greater than about 600 pmol/L, greater than about 650 pmol/L, greater than about 700 pmol/L, greater than about 750 pmol/L, greater than about 800 pmol/L, greater than about 900 pmol/L, greater than about 1000 pmol/L, greater than about 1100 pmol/L, greater than about 1200 pmol/L, greater than about 1300 pmol/L, greater than about 1400 pmol/L, greater than about 1500 pmol/L, or more.

[00132] In certain embodiments, a subject suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has been diagnosed with classic phenylketonuria (PKU) due to PAH deficiency. In certain embodiments, a subject suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has two plasma Phe values with a concentration of greater than about 600 pmol/L drawn at least 48 hours apart and has at least one historical value greater than about 600 pmol/L in the preceding 12 months. In certain embodiments, a subject suitable for employing a method of the present disclosure comprising administering an rAAV described herein, is able to maintain a baseline diet (e.g. , ±25% of average total protein intake (intact and medical), whether Phe-restricted or unrestricted) after employing the method of the present disclosure. In certain embodiments, if applicable, a subject suitable for employing a method of the present disclosure comprising administering an rAAV described herein, is able to maintain a stable dose of medication for attention-deficient/hyperactivity disorder (ADHD), depression, anxiety, or other psychiatric disorder for ±8 weeks prior to start of the method of the present disclosure, and is able to maintain stable dose throughout the treatment. In certain embodiments, a subject suitable for employing a method of the present disclosure comprising administering an rAAV described herein, if of childbearing potential, will use effective contraception for 12 months following employing the method of the present disclosure, including the use of barrier contraception during the 6 months following treatment.

[00133] In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has PKU that is not due to PAH deficiency. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has detectable presence of an AAV neutralizing antibody directed against an AAV capsid protein as described herein. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has a history of or positive test result for human immunodeficiency virus (HIV). In certain embodiments, a subj ect not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has history of or positive test result for hepatitis C virus antibody or hepatitis B vims (defined as positive for both hepatitis B surface antigen and hepatitis B core antibody), or is undergoing antiviral therapy for hepatitis B or C . In certain embodiments, a subj ect not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has history of significant underlying liver disease, liver transplant, genetic liver disease, cirrhosis, NASH, or other liver condition. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has history of drug abuse or alcoholism that would limit the subject participating in the treatment. In certain embodiments, a subj ect not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has ALT >1 5X upper limit of normal (ULN) and AST > 1.5X ULN. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has alkaline phosphatase value of >1.5X ULN. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has total bilirubin value of >1 5X ULN, and/or direct bilirubin value of >1.5X ULN. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has serum creatinine level of >1.5X ULN. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has hematology values outside the normal range (e.g., hemoglobin < ll.Og/dL for males or <10.0 g/dL for females; white blood cells <3,000/pL; absolute neutrophils <l,500/pL; platelets <100,000/pL). In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has hemoglobin Ale value >7.9% or fasting glucose >200 mg/dL. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has a contraindication to steroid use or conditions that would worsen in the presence of corticosteroids. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has previously received gene therapy for the treatment of any condition. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has used in the past 30 days levodopa. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has presence of an untreated or inadequately treated active infection or an infection requiring systemic antiviral or antimicrobial therapy. In certain embodiments, a subject not suitable for employing a method of the present disclosure comprising administering an rAAV described herein, has used any medication that is intended to treat PKU, including the use of large neutral amino acids (LNAAs), within 30 days prior to start of treatment.

[00134] Accordingly, in certain embodiments, a method of the present disclosure comprising administering an rAAV described herein to a subject having a disease or disorder associated with a PAH gene mutation, at a dose described herein, may result in a reduction in plasma Phe concentration to less than about 360 pmol/L ( e.g . , less than about 340 pmol/L. less than about 320 pmol/L, less than about 300 pmol/L, less than about 280 pmol/L, less than about 260 pmol/L, less than about 240 pmol/L, less than about 220 pmol/L, less than about 200 pmol/L, less than about 180 pmol/L, less than about 160 pmol/L, less than about 140 pmol/L, or less than about 120 pmol/L). In certain embodiments, a method of the present disclosure comprising administering an rAAV described herein to a subject having a disease or disorder associated with a PAH gene mutation, at a dose described herein, may result in a reduction in plasma Phe concentration to less than about 120 pmol/L (e.g., less than about 110 pmol/L, less than about 100 pmol/L, less than about 90 pmol/L, less than about 80 pmol/L, less than about 70 pmol/L, less than about 60 pmol/L, less than about 50 pmol/L, less than about 40 pmol/L, less than about 30 pmol/L, less than about 20 pmol/L, or less than about 10 pmol/L.

[00135] In certain embodiments, the reduction in plasma Phe levels in a subject administered an rAAV as described herein may persist for at least 2 weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, 18 months, 19 months, 20 months, 21 months, 22 months, 23 months, 2 years, 3 years, 4 years, 5 years, 6 years, 7 years, 8 years, 9 years, 10 years, 15 years, or more than 15 years.

Immunosuppressant Resimens

[00136] In certain embodiments, liver-directed rAAV delivery to subjects may result in an immune response to the rAAV. In certain embodiments, the immune response to the rAAV is evidenced by an increase in liver function tests. Liver function tests include assaying the levels of certain enzymes and proteins in the blood. Various liver function tests are known in the art including, for example, assaying the level of alanine transaminase (ALT); aspartate transaminase (AST); alkaline phosphatase (ALP); albumin and total protein; bilirubin; gamma- glutamyltransferase (GGT); and L-lactate dehydrogenase (LD), and assaying the time it takes blood to clot (also known in the art as prothrombin time (PT)). In certain embodiments, the immune response to the rAAV is evidenced by an increase in AAV capsid-specific T cells in the peripheral blood. As known in the art, capsid-specific CD8+ T cell responses peak within 4-8 weeks and are coincident with elevations in serum ALT and AST and elimination of AAV- transduced cells. Further, humoral immunity to the AAV capsid has been shown to occur within 2-4 weeks of viral delivery. In certain embodiments, elevated transaminases (e.g., elevated levels of ALT and AST) are observed in subjects, and may be self-limited and unaccompanied by additional signs of liver toxicity. The elevation of transaminases (e.g., ALT and AST; known as transaminitis) can be controlled by the administration of anti-inflammatory and/or immunosuppressive therapies (e.g., an immunosuppressant regimen).

[00137] In certain embodiments, the subject is administered a prophylactic immunosuppressant regimen (e.g. , a prophylactic prednisolone regimen) before administration of the rAAV of the present disclosure. In certain embodiments, the subject is administered a prophylactic immunosuppressant regimen one day before administration of the rAAV of the present disclosure. In certain embodiments, the subject is administered a prophylactic immunosuppressant regimen therapy during administration of the rAAV of the present disclosure. In certain embodiments, the subject is administered a prophylactic immunosuppressant regimen after administration of the rAAV of the present disclosure. In certain embodiments, the subject is administered a prophylactic immunosuppressant regimen before, during, and/or after administration of the rAAV of the present disclosure. A prophylactic immunosuppressant regimen described herein may limit the immunologic response in the liver and to maintain PAH expression and prevent loss of vector. [00138] In certain embodiments, the duration and doses of the immunosuppressant regimen are intended to cover the anticipated period of peak immune response (e.g., about 8 weeks following viral delivery), followed by a gradual taper. It will be readily apparent to those of skill in the art (e.g., an attending physician) that administration of the immunosuppressant regimen, including gradual taper thereof, will depend on the general tolerability of the subject to the immunosuppressant regimen.

[00139] The route of administration of the immunosuppressant regimen will readily be able to be determined by those of skill in the art. In certain embodiments, the immunosuppressant regimen will be administered orally. In certain embodiments, the immunosuppressant regimen will be administered systemically (e.g., via intravenous or parenteral routes).

[00140] Suitable immunosuppressant regimens are known in the art and include use of corticosteroids. Accordingly, in certain embodiments, the subject is administered a corticosteroid (e.g., prednisolone) before, during, and/or after administration of the rAAV of the present disclosure. In certain embodiments, the corticosteroid is glucocorticoid. Examples of corticosteroids include, without limitation, hydrocortisone, cortisone, ethamethasoneb, prednisone, prednisolone, triamcinolone, methylprednisolone, and dexamathasone. In certain embodiments, the subject is administered prednisolone before, during, and/or after administration of the rAAV of the present disclosure.

[00141] In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered to the subject before administration of the rAAV of the present disclosure. In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered to the subject at least one day, at least two days, at least three days, at least four days, at least five days, at least six days, at least seven days, at least eight days, at least nine days, or at least ten days, before administration of the rAAV of the present disclosure. In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered to the subject one day before administration of the rAAV of the present disclosure.

[00142] In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered to the subject for about 20 or about 21 weeks. In certain embodiments, the immunosuppressant regimen (e.g. , prednisolone regimen) is administered to the subject for at least about one week, at least about two weeks, at least about three weeks, at least about four weeks, at least about five weeks, at least about six weeks, at least about seven weeks, at least about eight weeks, at least about nine weeks, at least about ten weeks, at least about eleven weeks, at least about twelve weeks, at least about thirteen weeks, at least about fourteen weeks, at least about fifteen weeks, at least about sixteen weeks, at least about seventeen weeks, at least about eighteen weeks, at least about nineteen weeks, at least about twenty weeks, at least about twenty one weeks, or at least about twenty two weeks. It will be appreciated by those of skill in the art that the duration of the immunosuppressant regimen described herein may depend on the tolerability of the subject to the therapy, and or depend on clinical developments during the course of the therapy. For example, in certain embodiments, if at any time during the immunosuppressant regimen, the subject exhibits an abnormal result of a liver function test (e.g., exhibits an abnormal serum level of one or more liver enzymes), the immunosuppressant regimen may be restarted and/or modified to include additional doses for additional durations. In such embodiments the duration of the immunosuppressant regimen will be prolonged, e.g., beyond the about 20 week duration.

[00143] In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered at doses described in prednisolone equivalents. As used herein, the term “prednisolone equivalent” refers to a dose of a corticosteroid that results in substantially the same effect as the effect of a certain dose of prednisolone (e.g., immunosuppressive effect of a certain dose of prednisolone) when administered to a subject. For example, a 5 mg dose of prednisolone is known in the art to elicit substantially the same effect as 0.75 mg of dexamethasone when administered to a subject. As such, a 5 mg dose in prednisolone equivalents is readily understood by those of skill in the art to encompass a 5 mg dose of prednisolone, or a 0.75 mg dose of dexamethasone. Corticosteroid equivalency conversion tables are available to and accessible by those of skill in the art and can be readily accessed from, for example, a clinical decision support resource such as UpToDate. In certain embodiments, the duration and doses of the immunosuppressant regimen are calculated according to the corticosteroid equivalency conversion values as shown in Table 1.

Table 1: Corticosteroid Equivalent Doses

[00144] In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered at a certain dose per day. For example, the therapy can comprise a dose in mg per day. In certain embodiments, the immunosuppressant regimen (e.g., prednisolone or dexamethasone regimen) is administered according to a weight-based dose, e.g., at a certain dose according to the weight of a subject, per day. For example, the therapy can comprise a dose in mg per kg of a subject per day.

[00145] In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered at about 1 mg/day to about 100 mg/day. In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered at about 1 mg/day to about 100 mg/day in prednisolone equivalents. In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered at about 1 mg/day, about 5 mg/day, about 10 mg/day, about 15 mg/day, about 20 mg/day, about 25 mg/day, about 30 mg/day, about 35 mg/day, about 40 mg/day, about 45 mg/day, about 50 mg/day, about 55 mg/day, about 60 mg/day, about 65 mg/day, about 70 mg/day, about 75 mg/day, about 80 mg/day, about 85 mg/day, about 90 mg/day, about 95 mg/day, or about 100 mg/day. In certain embodiments, the immunosuppressant regimen (e.g., prednisolone regimen) is administered at about 1 mg/day, about 5 mg/day, about 10 mg/day, about 15 mg/day, about 20 mg/day, about 25 mg/day, about 30 mg/day, about 35 mg/day, about 40 mg/day, about 45 mg/day, about 50 mg/day, about 55 mg/day, about 60 mg/day, about 65 mg/day, about 70 mg/day, about 75 mg/day, about 80 mg/day, about 85 mg/day, about 90 mg/day, about 95 mg/day, or about 100 mg/day in prednisolone equivalents.

[00146] In certain embodiments, specific doses of the immunosuppressant regimen are administered according to a sequential dosing regimen. In certain embodiments, the immunosuppressant regimen is administered according to a sequential dosing regimen. In certain embodiments, the immunosuppressant regimen is administered according to the following sequential dosing regimen: about 60 mg/day in prednisolone equivalents for about two weeks; about 40 mg/day in prednisolone equivalents for about six weeks; about 30 mg/day in prednisolone equivalents for about three weeks; about 20 mg/day in prednisolone equivalents for about three weeks; about 10 mg/day in prednisolone equivalents for about five weeks; and about 5 mg/day in prednisolone equivalents for about one week. In certain embodiments, the final step of about 5 mg/day in prednisolone equivalents for about one week may be continued for a total of about two weeks. In certain embodiments, specific doses of the immunosuppressant regimen are administered according to a sequential dosing regimen. In certain embodiments, the prednisolone is administered according to a sequential dosing regimen. In certain embodiments, the prednisolone is administered according to the following sequential dosing regimen: about 60 mg/day for about two weeks; about 40 mg/day for about six weeks; about 30 mg/day for about three weeks; about 20 mg/day for about three weeks; about 10 mg/day for about five weeks; and about 5 mg/day for about one week. In certain embodiments, the final step of about 5 mg/day for about one week may be continued for a total of about two weeks.

[00147] In certain embodiments, a subject experiences elevated AST and/or ALT levels greater than 2 times the upper limit of normal (ULN) during the prophylactic immunosuppressant regimen described herein. In such embodiments, the immunosuppressant regimen will be re-escalated or re-started at a certain dose.

[00148] Accordingly, in certain embodiments, where a subject experiences elevated levels of AST and/or ALT greater than 2 times the upper limit of normal (ULN) during a prophylactic prednisolone sequential dosing regimen, for example, about 60 mg/day for two weeks; about 40 mg/day for six weeks; about 30 mg/day for three weeks; about 20 mg/day for three weeks; about 10 mg/day for five weeks; and about 5 mg/day for one or two weeks, the prednisolone will be re-escalated or re-started at 60 mg/day, and then tapered again, according to the same sequential dosing regimen, e.g., about 60 mg/day for two weeks; about 40 mg/day for six weeks; about 30 mg/day for three weeks; about 20 mg/day for three weeks; about 10 mg/day for five weeks; and about 5 mg/day for one or two weeks.

[00149] In certain embodiments, a subject experiences elevated levels of AST and/or ALT greater than 2 times the upper limit of normal following the end of a prophylactic immunosuppressant regimen described herein. In such embodiments, the immunosuppressant regimen will be re-started according to a modified regimen.

[00150] Accordingly, in certain embodiments, where a subject expen ences elevated levels of AST and/or ALT greater than 2 times the upper limit of normal (ULN) following the end of a prophylactic prednisolone sequential dosing regimen, for example, about 60 mg/day for two weeks; about 40 mg/day for six weeks; about 30 mg/day for three weeks; about 20 mg/day for three weeks; about 10 mg/day for five weeks; and about 5 mg/day for one or two weeks, the prednisolone will be re-started according to the following dosing regimen: about 60 mg/day for two weeks or until ALT and/or AST levels have declined to below or about the subject’s baseline levels; about 40 mg/day for two weeks; about 30 mg/day for two weeks; about 20 mg/day for two weeks; about 10 mg/day for two weeks; and about 5 mg/day for two weeks. In certain embodiments, the taper below the about 60 mg/day prednisolone for two weeks does not start until the ALT and/or AST levels have declined to the subject’s baseline levels, provided that the subject tolerates the regimen. In certain embodiments, the duration of the about 60 mg/day prednisolone dose does not exceed four weeks. In certain embodiments, where ALT and/or AST levels continue to rise at 60 mg/day or 40 mg/day, intravenous methylprednisolone may be administered.

Other Concomitant Therapy

[00151] In certain embodiments, subjects will continue their usual dietary regimen. In certain embodiments, the baseline diet will be established, and may be defined as ±25% of average total protein intake (intact and medical), whether Phe-restricted or unrestricted. In certain embodiments, the baseline diet will be maintained following administration of the rAAV of the present disclosure. In certain embodiments, modification of the diet may be made based on: (1) at 8 weeks, if three Phe values during the first 8 weeks are <360 pmol/L; and/or (2) prior to 8 weeks, if three Phe values during the first 8 weeks (measured at least one week apart) are <120 pmol/L.

[00152] In certain embodiments, subjects taking medications for the treatment of ADHD, depression, anxiety, or other psychiatric disorders at study entry must be on a stable dose for >8 weeks prior to administration of the rAAV of the present disclosure, and may continue with the same dose regimen throughout the study, unless otherwise determined by a physician for medical reasons.

[00153] In certain embodiments, use of any medications for PKU, including Kuvan®, LNAA, and Palynziq™, may be prohibited unless the plasma Phe concentration is considered to be unsafe for the subject, and it is determined that such treatment is medically necessary following modification of diet.

IV. Systems and Methods for Making rAAV

[00154] The rAAV used in the methods disclosed herein can be produced using any art recognized method. Packaging systems useful for the production of rAAV are described below. Methods for using such packaging systems are well known in the art.

[00155] In certain embodiments, packaging systems useful for producing rAAV comprise: first nucleotide encoding one or more AAV Rep proteins; a second nucleotide encoding a capsid protein of any of the AAVs as disclosed herein; and a third nucleotide sequence comprising any of the rAAV genome sequences as disclosed herein, wherein the packaging system is operative in a cell for enclosing the transfer genome in the capsid to form the AAV. In certain embodiments, the packaging system comprises a first vector comprising the first nucleotide sequence encoding the one or more AAV Rep proteins and the second nucleotide sequence encoding the AAV capsid protein, and a second vector comprising the third nucleotide sequence comprising the rAAV genome. As used in the context of a packaging system as described herein, a “vector” refers to a nucleic acid molecule that is a vehicle for introducing nucleic acids into a cell (e.g., a plasmid, a virus, a cosmid, an artificial chromosome, etc.).

[00156] Any AAV Rep protein can be employed in the packaging systems disclosed herein. In certain embodiments of the packaging system, the Rep nucleotide sequence encodes an AAV2 Rep protein. Suitable AAV2 Rep proteins may include, without limitation, Rep 78/68 or Rep 68/52. In certain embodiments of the packaging system, the nucleotide sequence encoding the AAV2 Rep protein comprises a nucleotide sequence that encodes a protein having a minimum percent sequence identity to the AAV2 Rep amino acid sequence of SEQ ID NO: 22, wherein the minimum percent sequence identity is at least 70% (e.g., at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 98%, at least 99%, or 100%) across the length of the amino acid sequence of the AAV2 Rep protein. In certain embodiments of the packaging system, the AAV2 Rep protein has the amino acid sequence set forth in SEQ ID NO: 22.

[00157] In certain embodiments of the packaging system, the packaging system further comprises a forth nucleotide sequence comprising one or more helper virus genes. In certain embodiments, the forth nucleotide sequence comprises adenoviral E2, E4 and VA genes. In certain embodiments of the packaging system, the packaging system further comprises a third vector (e.g. , a helper virus vector), comprising the forth nucleotide sequence. The third vector may be an independent third vector, integral with the first vector, or integral with the second vector.

[00158] In certain embodiments of the packaging system, the helper virus is selected from the group consisting of adenovirus, herpes virus (including herpes simplex virus (HSV)), poxvirus (such as vaccinia virus), cytomegalovirus (CMV), and baculovirus. In certain embodiments of the packaging system, where the helper virus is adenovirus, the adenovirus genome comprises one or more adenovirus RNA genes selected from the group consisting of El, E2, E4 and VA. In certain embodiments of the packaging system, where the adenovirus genome comprises one or more adenovirus RNA genes selected from the group consisting of E2, E4 and VA. In certain embodiments of the packaging system, where the helper virus is HSV, the HSV genome comprises one or more of HSV genes selected from the group consisting of UL5/8/52, ICPO, ICP4, ICP22 and UL30/UL42.

[00159] In certain embodiments of the packaging system, the first, second, and/or third vector are contained within one or more plasmids. In certain embodiments, the first vector and the third vector are contained within a first plasmid. In certain embodiments the second vector and the third vector are contained within a second plasmid.

[00160] In certain embodiments of the packaging system, the first, second, and/or third vector are contained within one or more recombinant helper viruses. In certain embodiments, the first vector and the third vector are contained within a recombinant helper virus. In certain embodiments, the second vector and the third vector are contained within a recombinant helper virus.

[00161] In certain embodiments of the packaging system comprises: a first nucleotide sequence encoding one or more AAV Rep proteins; a second nucleotide sequence encoding a capsid protein of any one of the AAV s described herein; a third nucleotide sequence comprising an rAAV genome sequence of any one of the AAVs described herein; and optionally a forth nucleotide sequence comprising one or more helper virus genes (e.g., adenoviral E2, E4 and VA genes).

[00162] In certain embodiments, rAAV can be produced using a method that comprises transfecting or transducing a cell with a packaging system as described herein under conditions operative for enclosing the rAAV genome in an AAV capsid to form a rAAV. Exemplary methods for recombinant preparation of an rAAV include transient transfection (e.g., with one or more transfection plasmids containing a first, and a second, and optionally a third vector as described herein), viral infection (e.g. with one or more recombinant helper viruses, such as a adenovirus, poxvirus (such as vaccinia virus), herpes virus (including HSV, cytomegalovirus, or baculovirus, containing a first, and a second, and optionally a third vector as described herein), and stable producer cell line transfection or infection (e.g., with a stable producer cell, such as a mammalian or insect cell, containing a Rep nucleotide sequence encoding one or more AAV Rep proteins and/or a Cap nucleotide sequence encoding one or more capsid proteins as described herein, and with a transfer genome as described herein being delivered in the form of a plasmid or a recombinant helper vims).

V. Additional Embodiments

[00163] The present disclosure is also described by the following embodiments. Embodiment 1. A method for treating a subject having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about 2el3 vg/kg to about 2el4 kg/vg, wherein the rAAV comprises: (a) an AAV capsid comprising a capsid protein; and (b) a transfer genome comprising a silently altered PAH coding sequence, wherein the silently altered PAH coding sequence comprises the nucleotide sequence set forth in SEQ ID NO: 1.

Embodiment 2. The method of Embodiment 1, wherein the transfer genome further comprises a transcriptional regulatory element operably linked to the silently altered PAH coding sequence.

Embodiment 3. The method of Embodiment 2, wherein the transcriptional regulatory element is capable of mediating transcription in a hepatocyte, a renal cell, or a cell in the brain, pituitary gland, adrenal gland, pancreas, urinary bladder, gallbladder, colon, small intestine, or breast.

Embodiment 4. The method of Embodiment 2, wherein the transcriptional regulatory element comprises a human hepatic control region 1 (HCR1) comprising the nucleotide sequence set forth in SEQ ID NO:2.

Embodiment 5. The method of Embodiment 2, wherein the transcriptional regulatory element comprises a human al -antitrypsin (hAAT) promoter comprising the nucleotide sequence set forth in SEQ ID NO:3.

Embodiment 6. The method of Embodiment 2, wherein the transcriptional regulatory element comprises an SV40 intron comprising the nucleotide sequence set forth in SEQ ID NO:4.

Embodiment 7. The method of Embodiment 2, wherein the transcriptional regulatory element comprises the nucleotide sequence set forth in SEQ ID NO:5.

Embodiment 8. The method of any one of the preceding Embodiments, wherein the transfer genome further comprises an SV40 polyadenylation sequence 3' to the PAH coding sequence, wherein the SV40 polyadenylation sequence comprises the nucleotide sequence set forth in SEQ ID NO: 6.

Embodiment 9. The method of any one of the preceding Embodiments, wherein the transfer genome comprises the nucleotide sequence set forth in SEQ ID NO: 7.

Embodiment 10. The method of any one of the preceding Embodiments, wherein the transfer genome further comprises a 5' inverted terminal repeat (5' ITR) nucleotide sequence 5' of the genome, and a 3' inverted terminal repeat (3' ITR) nucleotide sequence 3’ of the genome Embodiment 11. The method of Embodiment 10, wherein the 5' ITR nucleotide sequence has at least 95% sequence identity to SEQ ID NO:8, and the 3' ITR nucleotide sequence has at least 95% sequence identity to SEQ ID NO:9.

Embodiment 12. The method of any one of the preceding Embodiments, wherein the transfer genome comprises the nucleotide sequence set forth in SEQ ID NO: 10.

Embodiment 13. The method of any one of the preceding Embodiments, wherein the AAV capsid comprises: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R.

Embodiment 14. The method of any one of the preceding Embodiments, wherein the AAV capsid comprises: a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the ammo acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R. Embodiment 15. The method of any one of the preceding Embodiments, wherein the AAY capsid comprises a capsid protein comprising the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, a capsid protein comprising the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, and/or a capsid protein comprising the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11.

Embodiment 16. The method of any one of the preceding Embodiments, wherein the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, and/or the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11. Embodiment 17. A method for treating a subject having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about 2el3 vg/kg to about 2el4 kg vg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO:l 1, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NOT 1, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO: 7 or SEQ ID NO: 10.

Embodiment 18. The method of Embodiment 17, wherein the AAV capsid comprises: a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 99% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R.

Embodiment 19. The method of Embodiment 17, wherein the AAV capsid comprises: a capsid protein comprising the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11; a capsid protein comprising the amino acid sequence of amino acids 138-736 of SEQ ID NO:ll; and or a capsid protein comprising the amino acid sequence of amino acids 1-736 of SEQ ID NO:ll.

Embodiment 20. The method of Embodiment 17, wherein: the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11; the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11; and/or the amino acid sequence of the capsid protein consists of the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11.

Embodiment 21. The method of any one of the preceding Embodiments, wherein the dose is about 2el3 vg/kg. Embodiment 22. The method of any one of the preceding Embodiments, wherein the dose is about 6el3 vg/kg. Embodiment 23. The method of any one of the preceding Embodiments, wherein the dose is about 8el3 vg/kg. Embodiment 24. The method of any one of the preceding Embodiments, wherein the dose is about lel4 vg/kg. Embodiment 25. The method of any one of the preceding Embodiments, wherein the dose is about 2el4 vg/kg. Embodiment 26. The method of any one of the preceding Embodiments, wherein the rAAV is administered as a single dose.

Embodiment 27. The method of any one of Embodiments 1 to 25, wherein the rAAV is administered as multiple doses.

Embodiment 28. The method of any one of the preceding Embodiments, wherein the rAAV is administered intravenously. Embodiment 29. The method of any one of the preceding Embodiments, wherein the subject is a pediatric subject.

Embodiment 30. The method of any one of Embodiments 1 to 28, wherein the subject is an adult subject.

Embodiment 31. The method of any one of the preceding Embodiments, wherein the subject is administered a prophylactic anti-inflammation therapy before, during, and/or after administration of the rAAV.

Embodiment 32. The method of Embodiment 31, wherein the prophylactic anti inflammation therapy is administered to the subject before administration of the rAAV, optionally 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 days before administration of the rAAV.

Embodiment 33. The method of Embodiment 31, wherein the prophylactic anti inflammation therapy is administered to the subject for at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,

12, 13, 14, 15, 16, 17, 18, 19 or 20 weeks.

Embodiment 34. The method of any one of Embodiments 31 to 33, wherein the anti inflammation therapy is a glucocorticosteroid.

Embodiment 35. The method of Embodiment 34, wherein the glucocorticosteroid is prednisolone.

Embodiment 36. The method of Embodiment 35, wherein the prednisolone is administered at about 1 to about 100 mg/day, optionally, about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100 mg/day.

Embodiment 37. The method of Embodiment 35, wherein the prednisolone is administered according to the following sequential dosing regimen: 60 mg/day for two weeks; 40 mg/day for six weeks; 30 mg/day for three weeks; 20 mg/day for three weeks; 10 mg/day for five weeks; and 5 mg/day for one week.

Embodiment 38. The method of any one of the preceding Embodiments, wherein the disease or disorder associated with a PAH gene mutation is phenylketonuria (PKU). Embodiment 39. A method for treating a subject having a disease or disorder associated with a PAH gene mutation, the method comprising intravenously administering to the subject an rAAV at a dose of about 2el3 vg/kg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11 , wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

Embodiment 40. A method for treating a subject having a disease or disorder associated with a PAH gene mutation, the method comprising intravenously administering to the subject an rAAV at a dose of about 6el3 vg/kg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an ammo acid sequence having at least 95% sequence identity with the ammo acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11 , wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

Embodiment 41. A method for treating a subject having a disease or disorder associated with a PAH gene mutation, the method comprising intravenously administering to the subject an rAAV at a dose of about 8el3 vg/kg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11 , wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

Embodiment 42. A method for treating a subject having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about lel4 vg/kg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

Embodiment 43. A method for treating a subject having a disease or disorder associated with a PAH gene mutation, the method comprising administering to the subject an rAAV at a dose of about 2el4 vg/kg, wherein the rAAV comprises: (a) an AAV capsid comprising: a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 203-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 138-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and/or a capsid protein comprising an amino acid sequence having at least 95% sequence identity with the amino acid sequence of amino acids 1-736 of SEQ ID NO: 11, wherein the amino acid in the capsid protein corresponding to amino acid 346 of SEQ ID NO: 11 is A, and wherein the amino acid in the capsid protein corresponding to amino acid 505 of SEQ ID NO: 11 is R; and (b) a transfer genome comprising the nucleotide sequence set forth in SEQ ID NO:7 or SEQ ID NO: 10.

VI. Examples

[00164] The following examples are offered by way of illustration, and not by way of limitation. Example 1: Human PAH transfer vector

[00165] The AAV gene transfer vector pHMI-hPAH-TC-025, as shown in Figure 1, comprises 5' to 3' the following genetic elements: a truncated 5' ITR element, a human hepatic control region 1 (HCR1), a human al -antitrypsin (hAAT) promoter, an SV40 intron, a silently altered human PAH coding sequence, an SV40 polyadenylation sequence, and a modified 3' ITR element. The sequences of these elements are set forth in Table 2. The truncated 5' ITR allows the vector to form a double-stranded AAV genome after transduction into cells. This vector is capable of expressing a human PAH protein in a human hepatocyte.

Table 2: Genetic elements in human PAH transfer vector pHMI-hPAH-TC-025

Example 2: Efficacy of a PAH transfer vector in a mouse model of PKU

[00166] Pah ¹ (PAH ^cml ) mice were housed in clear polycarbonate cages with contact bedding in an isolator. Picolab Mouse Diet 5058 was provided to the animals ad libitum. Spring or tap water acidified with IN HC1 to a targeted pH of 2.5 - 3.0 was provided ad libitum. Vectors packaged in AAVHSC15 capsid were prepared in PBS (with Ca and Mg), supplemented with 35 mM NaCl, 1% sucrose, and 0.05% Pluronic F-68. The formulation was injected intravenously via the tail vein.

[00167] Blood samples were collected every week after the administration of the PAH transfer vector (0 week: prior to administration) by facial vein puncture or tail snip. The samples were allowed to clot at room temperature for at least 30 minutes, centrifuged at ambient temperature at minimum 1000 x g for 10 minutes and the serum samples were extracted. Serum samples were stored at -70 °C. Serum phenylalanine and tyrosine levels were measured by tandem mass spectrometry. [00168] For collection of tissue samples, the animals underwent cardiac perfusion with saline. Liver (caudate lobe), kidney (left), brain, heart, and muscle (quadriceps) tissues were snap frozen in liquid nitrogen and stored at -70 °C. The snap frozen tissues were ground into powder in liquid nitrogen in a mortar and pestle and divided in to aliquots to test for PAH expression for vector genome biodistribution by qPCR. [00169] To examine the long-term efficacy of an rAAV comprising pHMI-hPAH-TC-

025 packaged in AAVHSC 15 capsid, a single dose of 2.6 ^c 10 ¹³ vector genomes per kg of body weight was administered to male Pah ¹ (PAH ^emi2 ) mice, and a single dose of 6 ^c 10 ¹³ vector genomes per kg of body weight was administered to female Pah ¹ ( PAH ^eml ) mice. As shown in Figures 2A and 2B, the administration of the pHMI-hPAH-TC-025 -containing rAAV led to significant reduction of Phe levels within one week. This reduction persisted for at least 48 weeks in male mice, and at least 46 weeks in female mice. An increase of PAH mRNA was observed by ddPCR in the liver samples of these mice collected 4 weeks post injection relative to the mice not administered the rAAV vector. An increase of the PAH enzymatic activity was also detected in liver samples by mass spectrometry. [00170] The efficacy of different doses of the pHMI-hPAH-TC-025-containing rAAV described above was further assessed. A single dose of 2.6 ^c 10 ¹¹ , 2.6 ^c 10 ¹² , or 2.6 ^c 10 ¹³ vector genomes per kg of body weight was administered to male mice and female Pah ¹ ( PAPP ^ml ) mice, and the serum levels of Phe and Tyr were measured. As shown in Figures 3A-3D, the dose of 2.6 ^c 10 ¹³ vector genomes per kg of body weight reduced the Phe levels and increased the Tyr levels more significantly than the two lower doses, and maintained complete reduction of serum Phe levels during the time examined in both male and female subjects.

Example 3: Clinical study of a PAH transfer vector

[00171] This example describes the protocol for a Phase 1/2, randomized, concurrently- controlled, dose escalation study to evaluate the safety and efficacy of a rAAV comprising the pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid, in adult phenylketonuria (PKU) subjects with PAH deficiency.

[00172] Subjects will undergo screening assessments prior to study entry, with the screening period lasting up to 45 days. Prior to administration of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid, subjects will be admitted to the clinical research unit and prophylactic steroid administration will be initiated. One approximately 120-minute administration of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid will occur in a clinical research unit setting. Subjects may be discharged home after they have been observed for at least 24 hours in the clinical research unit following administration of pHMI-hPAH-TC- 025 vector packaged in AAVHSC15 capsid, provided they are clinically stable. Subjects will continue their usual dietary regimen (either Phe-restricted or unrestricted diet) during the screening period and following administration of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid.

[00173] Subjects will undergo safety and efficacy observation for 52 weeks in this study following administration of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid. Up to three dose levels of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid will be investigated. All doses are anticipated to provide a clinically relevant decrease in plasma Phe concentration. At a given dose level, 2 subjects will be enrolled and dosed initially. Dosing of the first 2 subjects in each cohort will be staggered, with at least a 21 -day interval between dosing of each subject. At least 21-day safety follow-up and Phe concentration data for each subject will be reviewed before the subsequent subject is dosed in that cohort. [00174] Following evaluation of at least 21 days of data from the first 2 subjects in a cohort, a decision can be made to either: (1) escalate to the next dose level, (2) addone additional subject to the same cohort, or (3) expand the cohort at the selected dose to enroll up to 9 additional subjects. 6 subjects will be randomized to receive pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid and 3 subjects will be randomized to a concurrent delayed treatment control arm.

[00175] Decisions regarding dose escalation and expansion will be based on safety and changes in plasma Phe concentrations relative to the treatment guidelines for PKU. Treatment guidelines describe the range of 120-360 pmol/L as PAH deficiency not requiring treatment, and the normal range of blood Phe (e.g., plasma Phe) for an individual without hyperphenylalaninemia (HP A) or PKU as 58 ±14 (SD) pmol/L.

Inclusion and Exclusion Criteria

[00176] Suitable subjects for the study will be enrolled according to the inclusion and exclusion criteria set forth in Table 3.

Table 3: Inclusion and Exclusion Criteria _

Investigational Product, Dosage, and Mode of Administration [00177] pHMI-hPAH-TC-025 vector packaged in AAYHSC15 capsid will be administered intravenously over approximately 2-4 hours in the clinical research unit setting. The 3 cohorts of dose levels of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid to be investigated in the study are: (1) 2el3 vg/kg; (2) 6el3 vg/kg; (3) 8el3 vg/kg; and (4) lel4 vg/kg. Upper limit of dosage will be 2el4 vg/kg. Figure 4 is a study design schematic showing dose cohorts 1 to 3.

[00178] One day prior to administration of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid, subjects will be started on prophylactic oral prednisolone therapy which will be administered for 20 weeks as follows:

- Prednisolone 60 mg/day x 2 weeks

- Prednisolone 40 mg/day x 6 weeks

- Prednisolone 30 mg/day x 3 weeks

- Prednisolone 20 mg/day x 3 weeks

- Prednisolone 10 mg/day x 5 weeks

- Prednisolone 5 mg/day x 1 week (the investigator has the discretion to continue the 5 mg/day dose for a total of 2 weeks (i.e., 1 additional week) based on clinical judgment)

[00179] If a subject experiences elevated AST and/or ALT >2x ULN during the prophylactic prednisolone regimen, the steroid will be re-escalated or re-started at 60 mg/day, and then tapered again, according to the above schedule.

[00180] If a subject experiences elevated AST and/or ALT >2x ULN following the end of the prophylactic prednisolone regimen, the steroid will be re-started according to the following schedule, with modification allowed by the Investigator (in consultation with the Sponsor Medical Monitor or designee) based on laboratory parameters, the subject’s medical history and clinical course, and/or subject tolerance of the regimen:

- Prednisolone 60 mg/day x 2 weeks or until ALT and AST levels have declined to < subject’s baseline levels

- Prednisolone 40 mg/day x 2 weeks

- Prednisolone 30 mg/day x 2 weeks

- Prednisolone 20 mg/day x 2 weeks

- Prednisolone 10 mg/day x 2 weeks

- Prednisolone 5 mg/day x 2 weeks

[00181] The prednisolone taper below 60 mg/day should not be started until the ALT and AST have declined to baseline (pre-administration) levels, provided the subject tolerates the regimen. The dose of 60 mg/day may be continued up to 4 weeks, or the dose re-escalated to that level, if the ALT/AST rise again and/or it is otherwise determined to be necessary in the judgment of the Investigator in consultation with the Sponsor’s Medical Monitor or designee. After the ALT/AST have reduced again and/or the clinical situation is controlled, the subsequent taper may then proceed. The 60 mg/day dose should not exceed 4 weeks.

[00182] Subjects whose transaminase values continue to rise at 60 mg/day or 40 mg/day should be considered for treatment with intravenous methylprednisolone instead of oral prednisolone at the discretion of the Investigator, in consultation with the Sponsor’s Medical Monitor or designee.

[00183] If the Investigator determines that oral prednisone should be administered instead of oral prednisolone, the Investigator must discuss the rationale with the Sponsor’s Medical Monitor or designee and obtain Sponsor’s Medical Monitor’s or designee’s approval to allow this alternate steroid. It is anticipated that the dosing of prednisone and the taper schedule should be the same as that for prednisolone. The rationale, approval, and administration of prednisone instead of prednisolone must be documented in the subject’s study record.

[00184] If acute illness with fever occurs while the subject is on 5 mg/day or 10 mg/day of prednisolone, the dose should be doubled for 48 hours and then resumed at the previous dose and tapering schedule.

[00185] At any time that a subject on steroids (and up to 6 months following steroid discontinuation) undergoes major surgery or experiences major trauma or illness, stress steroids should be administered according to standard of care. Subjects will be informed of the risks of steroids including HPA axis suppression and other steroid-related side effects.

[00186] The intention is that Investigators and subjects will follow the steroid regimens as described in the protocol. However, it is recognized that uncommon situations could arise in which it is in the best interest of the subject to have the steroid dose reduced or discontinued. The steroid regimens are intended to suppress or control the immune response to the gene therapy and thereby preserve gene expression in the hepatocytes. A potential additional goal for the steroid regimen that addresses increased LFTs is to protect the liver cells by addressing the liver inflammation, if severe. These factors need to be taken into account if the Investigator is considering reducing the dose of steroids or discontinuing the steroids in the setting of a clinically important event such as steroid-related psychosis or herpetic comeal ulceration. If the Investigator sees the need to reduce or discontinue the steroids, the Sponsor’s Medical Monitor or designee must be consulted prior to the Investigator modifying the steroid dosing (unless time does not permit this in an immediately life-threatening situation).

Concomitant Therapy

[00187] Subjects will continue their usual dietary regimen during the screening penod. The baseline diet will be established during the screening period, defined as ±25% of average total protein intake (intact and medical), whether Phe-restricted or unrestricted. The baseline diet will be maintained following administration of pHMI-hPAH-TC-025 vector packaged in AAYHSC15 capsid. A recommendation to modify the diet may be made at the discretion of the Investigator, Site Dietician, and in consultation with the Sponsor Medical Monitor or designee based on the following guidelines:

- At 8 weeks, if three Phe values during the first 8 weeks are <360 pmol/L

- Prior to 8 weeks, if three Phe values during the first 8 weeks (measured at least one week apart) are <120 pmol/L

[00188] Subjects taking medications for the treatment of ADHD, depression, anxiety, or other psychiatric disorders at study entry must be on a stable dose for >8 weeks prior to administration of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid and must continue with the same dose regimen throughout the study, unless it is determined that changes should be made for medical reasons.

[00189] Use of any medications for PKU, including Kuvan®, LNAA, and Palynziq™, is prohibited for the duration of the study unless the plasma Phe concentration is considered to be unsafe for the subject, and it is determined that such treatment is medically necessaiy following modification of diet.

Objectives and Endpoints

[00190] The primary objective of the study is to evaluate the safety, tolerability, and efficacy of a single dose of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid when administered to subjects with phenylalanine hydroxylase (PAH) deficiency.

[00191] The primary safety endpoint is incidence and severity of treatment emergent adverse events (TEAEs) and serious TEAEs. The primary efficacy endpoint is incidence of sustained plasma Phe concentration of <360 pmol/L at 24 weeks following administration of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid. Sustained plasma Phe concentration is defined as at least two plasma Phe measurements <360 pmol/L between 16 and 24 weeks. [00192] The secondary objectives of the study are to evaluate the effect of pHMI-hPAH- TC-025 vector packaged in AAVHSC15 capsid on plasma phenylalanine (Phe) concentration relative to treatment guidelines for PKU, to assess durability of response, and to characterize the presence of vector and immune response following administration of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid.

[00193] The key secondary endpoint is measurement of plasma Phe concentration at 24 weeks post-treatment. Additional secondary endpoints include:

- Incidence of achieving a plasma Phe concentration <360 pmol/L at each time point during the study

- Incidence of achieving a plasma Phe concentration <120 pmol/L at each timepoint during the study

- Assessment of presence of vector DNA in blood

- Assessment of vector shedding in urine, stool, and saliva

- Measurement of anti-AAVHSC15 antibodies (IgG and neutralizing), anti -PAH transgene antibody titers, and cytotoxic T-lymphocyte response (ELISPOT).

Safety and tolerability (including incidence of dose-limiting toxicities)

Results

[00194] Two patients in Cohort 1 (low-dose) and one patient in Cohort 2 (mid-dose) received pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid. Preliminary safety data from Cohorts 1 and 2 showed that administration of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid was well tolerated. Figures 5A-5C show data from the three dosed patients. The first patient in Cohort 2 indicated a dose-response effect with an observed reduction in phenylalanine (Phe) levels from baseline (Figure 5A), increase in tyrosine (Tyr) (Figure 5B), and reduction in the Phe/Tyr ratio (Figure 5C), suggestive of increased enzymatic activity. Phe is a registrable endpoint in PKU, Tyr is a product of Phe metabolism and a precursor to neurotransmitters, and the Phe/Tyr ratio is a clinically relevant diagnostic measurement for PKU.

[00195] No treatment-emergent adverse events (TEAEs) or serious TEAEs were observed. All patients’ ALT (alanine aminotransferase) and AST (aspartate aminotransferase) levels remained within the normal range. Cohort 1 safety profile enabled dose escalation to Cohort 2.

[00196] The first patient dosed in Cohort 2 experienced a reduction in Phe of 35% and 48% from baseline at weeks 1 and 4, respectively, as compared to Cohort 1, which generally did not show a reduction in Phe through weeks 10 and 12 (Figure 5A). In Figure 5A, the mean pre-treatment fasting Phe concentration in pmol/L was 1,187 for patient 1 (n = 7 measurements); 1,178 for patient 2 (n = 4 measurements); and 779 for patient 3 (n = 5 measurements). The results are consistent with a dose-response effect of administration of pHMI-hPAH-TC-025 vector packaged in AAYHSC15 capsid. Per protocol, patient baseline is defined as one day prior to dosing. The first patient dosed in Cohort 2 also showed increases in Tyr levels of 72% and 85% at weeks 1 and 4, respectively, suggesting increased PAH enzyme activity (Figure 5B). In Figure 5B, the mean pre-treatment fasting Tyr concentration in pmol/L was 36.54 for patient 1 (n = 7 measurements); 77.08 for patient 2 (n = 4 measurements); and 49.00 for patient 3 (n = 5 measurements). In addition, the patient experienced a 62% and 72% reduction in the Phe/Tyr ratio from baseline to weeks 1 and 4, respectively (Figure 5C). All patients reported maintaining consistent protein intake pre- and post-treatment. In Figure 5C, the mean pre-treatment fasting Phe/Tyr ratio level was 32.8 for patient 1 (n = 7 measurements); 22.1 for patient 2 (n = 4 measurements); and 16.3 for patient 3 (n = 5 measurements).

Results

[00197] The above protocol was modified such that Cohort 3 was administered a dose of lel4 vg/kg of AAV vector, rather than 8el3 vg/kg. Accordingly, pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid was administered intravenously to six patients, according to three dosing cohorts (two patients each): (1) low-dose cohort: 2el3 vg/kg; (2) mid-dose cohort: 6el3 vg/kg; and (3) high-dose cohort: lel4 vg/kg.

[00198] Table 4 shows a summary of the baseline characteristics for each patient. Table 4: Patient Baseline Characteristics

[00199] Data for each individual patient is shown in Figures 6-11. Figures 6, 7, 8, 9, 10, and 11 are graphs showing the level of plasma Phe over time, for patients 1, 2, 3, 4, 5, and 6, respectively. Mean percent change from baseline (% CFB) values for Phe, Tyr, and Phe to Tyr ratio (P/T) were derived as follows: for each subject, a mean post-baseline value was derived for each analyte by summing all post-baseline values and dividing by the total number of visits. Mean post-baseline change was then calculated by subtracting the baseline value from the mean post-baseline value for each analyte. Mean percent change from baseline (% CFB) was derived by dividing the mean post-baseline change value by the baseline value and multiplying by 100 for each analyte. Diet Mean % CFB values for intact protein, total protein, Phe intake, and Tyr intake were derived as follows: for each subject, a mean post-baseline value was derived for each nutrient by summing all post-baseline values and dividing by the total number of visits. Mean post-baseline change was then calculated by subtracting the baseline value from the mean post-baseline value for each nutrient. Mean % CFB was derived by dividing the mean post baseline change value by the baseline value and multiplying by 100 for each nutrient.

[00200] As shown in Figures 6 and 7, a meaningful reduction in plasma Phe was not observed in patients 1 and 2, respectively.

[00201] As shown in Figure 8, for patient 3, the mean % CFB showed a 48.6% reduction in plasma Phe, an 81.1 % increase in tyrosine, and a 70.8% decrease in Phe to Tyr ratio. Without being bound to any theory, this indicates PAH enzymatic activity and more normal metabolism. [00202] As shown in Figure 9, a reduction in the level of plasma Phe was not observed for patient 4. Despite the mean % CFB showing a 13% increase in plasma Phe, this patient experienced a dramatic mean % CFB increase in tyrosine of 131.1% and a decrease in Phe to Tyr ratio of 45.5%. Without being bound to any theory, this indicates PAH enzymatic activity that was enough to improve tyrosine, but not enough to reduce Phe. ** indicates that this patient began additional PKU medication after Week 36.

[00203] As shown in Figure 10, for patient 5, the mean % CFB showed a 10.8% reduction in plasma Phe, a 22.6% increase in tyrosine, and a 25.4% decrease in Phe to Tyr ratio.

[00204] As shown in Figure 11, a marked reduction in plasma Phe was observed for patient 6. For patient 6, the mean % CFB showed a 31.4% reduction in plasma Phe, a 40.3% increase in 40.3%, and a 52.4% decrease in Phe to Tyr ratio. Without being bound to any theory, this indicates PAH enzymatic activity and more normal metabolism. ** indicates that patient 6 Grade 1 was based on a baseline ALT value above ULN.

[00205] In Figures 6-11, WNL represents within normal of alanine aminotransferase (ALT) level for the reference laboratory, and ULN represents upper limit of normal of ALT level for the reference laboratory. P/T represents Phe/Tyr ratio, CFB represents change from baseline for last value, and * indicates a patient having a pre-existing immune condition. ALT Grades are based on Common Terminology Criteria for Adverse Events (CTCAE) Version 5. [00206] Figure 12 is a graph showing the level of plasma Phe over time, for patients 3 and 6, and shows that these patients have a similar trajectory in Phe reductions.

[00207] Figure 13 is a graph showing the percent change from baseline (% CFB) of the level of plasma Phe over time, for patients of Cohort 1.

[00208] Figure 14 is a graph showing the percent change from baseline (% CFB) of the level of plasma Phe over time, for patients of Cohorts 2 and 3. A comparison of mean % CFB between patients of Cohort 1 and patients of Cohorts 2 and 3 shows that significant plasma Phe reductions were observed at the higher doses (p<0.004; Post-hoc comparison of Cohort 1 vs Cohorts 2&3 using repeated measures MANOV A/regression analysis).

[00209] In Figures 13 and 14, analyses were conducted by first calculating % CFB PHE at each visit for all subjects. % CFB was then compared between cohorts using a repeated measures regression to account for the within subject correlation due to the multiple follow-up visits, with % CFB as the dependent variable and cohort, baseline PHE values and study day of the visit included as independent variables.

[00210] Significant reductions in plasma Phe levels were observed in mid- and high- dose cohorts, compared to low-dose Cohort 1 (p< 0.004; Post-hoc comparison of Cohort 1 vs Cohorts 2&3 using repeated measures MANOV A/regression analysis). Plasma Phe levels below 360 pmol/L (American College of Medical Genetics (ACMG) target Phe levels) were achieved in Cohort 2, with five values out to 48 weeks post-admmistration for patient 3; and Cohort 3, with one value out to 13 weeks post-administration for patient 6. Phe reduction, Tyr increase, and Phe/Tyr ratio decrease indicated PAH enzymatic activity.

[00211] The majority of patients self-liberalized dietary intact protein, e.g., increased their dietary intake of natural protein, and/or Phe intake. Table 5 shows a summaiy of change in protein intake for each patient. For each subject, a mean post-baseline value was derived for each nutrient by summing all post-baseline values and dividing by the total number of visits Mean post-baseline change was then calculated by subtracting the baseline value from the mean post-baseline value for each nutrient. Mean % CFB was derived by dividing the mean post baseline change value by the baseline value and multiplying by 100 for each nutrient.

Table 5: Change in Patient Dietary Protein Intake

[00212] It was found that pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid was generally well tolerated. No treatment-related serious adverse events (SAEs) were reported in the six dosed patients. One non-treatment-related SAE was observed in a patient that developed Herpes zoster. [00213] Transaminitis, as evidenced by elevated ALT, occurred in five patients. ALT elevations in Cohorts 2 and 3 were managed with increased steroids, as needed. Two Grade 3 ALT elevations were observed in patients 4 and 5, both with pre-existing immune conditions. Normal cortisol levels were observed in patient 4 during planned high-dose, prophylactic steroid therapy. The severity of ALT increase was found to be associated with pre-existing immune conditions. Without being bound to any theory, ALT increases may impact efficacy of pHMI-hPAH-TC-025 vector packaged in AAVHSC15 capsid. In Cohorts 2 and 3, Phe reductions were found to be greater in patients with Grade 1 ALT elevations compared to patients with Grade 3 ALT elevations (p<0.05; Post-hoc comparison of Patients 3 and 6 vs Patients 4 and 5 using repeated measures MANOV A/regression analysis). Table 6 summanzes the ALT elevation status for each patient. ALT Grades are based on Common Terminology Criteria for Adverse Events (CTCAE) Version 5.

Table 6: Patient ALT Elevation Status * Grade 1 based on baseline ALT value above ULN.

[00214] The invention is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described will become apparent to those skilled in the art from the foregoing description and accompanying figures. Such modifications are intended to fall within the scope of the appended claims.

[00215] All references (e.g., publications or patents or patent applications) cited herein are incorporated herein by reference in their entirety and for all purposes to the same extent as if each individual reference (e.g., publication or patent or patent application) was specifically and individually indicated to be incorporated by reference in its entirety for all purposes. Other embodiments are within the following claims.