A Phase I/II Study to Assess the Safety and Tolerability of ST-920, an AAV2/6 Human Alpha Galactosidase A Gene Therapy, in Subjects with Fabry Disease

Phase 1

• Conditions: Fabry Disease (X-linked lysosomal storage disease); MedDRA version: 24.1Level: PTClassification code 10016016Term: Fabry's diseaseSystem Organ Class: 10010331 - Congenital, familial and genetic disorders; Therapeutic area: Diseases [C] - Congenital, Hereditary, and Neonatal Diseases and Abnormalities [C16]

• Registration Number: EUCTR2019-000667-24-DE
• Lead Sponsor: Sangamo Therapeutics, Inc.

Brief Summary

Not available

Detailed Description

Not available

Study Timeline

• Study Start: 2021-06-02
• Last Update Posted: 29 July 2024

Recruitment & Eligibility

• Status: ot Recruiting
• Sex: Male
• Target Recruitment: 48

Inclusion Criteria

1. = 18 years of age
2. Signed, written informed consent
3. Diagnosis of Fabry disease
4. One or more of the following symptoms: i) cornea verticillata, ii) acroparesthesia, iii) anhidrosis, iv) angiokeratoma
5. Subjects who are on ERT or are ERT-naïve or are ERT-pseudo-naïve (defined as not having received ERT treatment during the 6 months prior to baseline). For subjects receiving ERT, ERT must have been administered at a stable dose and regimen for at least 6 months (defined as not having missed more than 3 doses of ERT during the 6 months prior to consent).
6. Subjects on migalastat (Galafold™) must agree to withdraw migalastat prior to Baseline and, if non-responder to migalastat (based on clinical and/or biochemical assessments), undergo an incisional skin biopsy and kidney biopsy.
7. Male subjects must refrain from sperm donation from the time of ST-920 administration until a minimum of 3 consecutive semen samples are negative for AAV2/6 after administration of ST-920 and a minimum of 90 days after ST-920 administration.
8. Subjects must agree to use a highly effective form of contraception from the time of ST-920 administration until a minimum of 90 days after ST-920 administration and a minimum of 3 consecutive semen samples are negative for AAV2/6 after administration of ST-920. Highly effective birth control methods include:
a. a documented vasectomy or permanent sterilization
b. condom
c. sexual abstinence is acceptable only as true abstinence and when in line with the preferred and usual lifestyle of the subject. Periodic abstinence (e.g. calendar, ovulation, symptothermal, post-ovulation methods) and withdrawal are not acceptable methods of contraception
9. Subject must be fully vaccinated (as per the Centers for Disease Control and Prevention (CDC) definition in the US and as per local guidelines in other countries) for COVID-19 at least one month prior to dosing
10. Renal function (not applicable for Renal cohort):
a. eGFR =60 ml/min/1.73m2
b. <1 g/g urine albumin to creatinine ratio (UACR) determined in a morning urine spot sample (and also determined by 24 hour urine analysis if the UACR is >500 mg/g)
Additional inclusion criteria for:
Cohorts 1-4b:
11. Male subjects with classical Fabry disease as defined by <5% a-Gal A activity in either plasma or leukocytes.
a. For male subjects who do not have documented diagnostic aGal A activity, a blood sample will be taken to measure aGal A activity (in plasma). For subjects who are on ERT, this blood draw must be taken at least 13 days after their last ERT infusion (trough)
b. If the subject’s a-Gal A activity is >5% and the subject is on ERT, this level of enzyme activity may be due to residual a-Gal A activity from the last ERT infusion. In this case, the diagnosis of classical Fabry disease may be confirmed if the following three criteria are fulfilled:
i. two or more documented symptomatic characteristics outlined in inclusion criterion #4. If there is documented clustered periumbilicial angiokeratoma, this symptom alone is sufficient as it is a pathognomonic sign of classical Fabry disease;
ii. a mutation that is indicative of classical Fabry (i.e. listed in a database, such as http://dbfgp.org); and
iii. the a-Gal A activity at trough is below the lower limit of the normal range of the assay
Renal and Cardiac cohorts:
12. Symptomatic Fabry disease defined for male subjects by <30% a-Gal A activity in either plasma or leukocytes
AND
Renal cohort:
13. Screening eGFR va

Exclusion Criteria

1. Positive neutralizing antibodies to AAV6
2. Intercurrent illness expected to impair evaluation of safety or efficacy during the observation period of the study
3. Patients receiving warfarin or other anticoagulants interfering with the ability to perform renal or skin biopsies, or patients with a clinically significant bleeding disorder
4. Active infection with hepatitis A virus (HAV ribonucleic acid [RNA] positive), active or occult hepatitis B virus infection (positive HBV-DNA or anti-HBc positive), active infection with hepatitis C virus (HCV RNA positive), infection with the human immunodeficiency virus (HIV) as measured by quantitative polymerase chain reaction (qPCR), or active or latent infection with tuberculosis (TB) measured by quantiferon test
5. Partner planning to become pregnant during required period of contraception.
6. History of liver disease such as clinically significant steatosis, fibrosis, non-alcoholic steatohepatitis (NASH) and cirrhosis, biliary disease within 6 months of informed consent; except for Gilbert’s syndrome
7. Elevated circulating serum AFP
8. For subjects receiving ERT, recent or recurrent hypersensitivity reaction manifested by significant infusion reaction to ERT treatment within 6 months prior to consent
9. One or more of the following:
i. Albumin = 3.5 g/dL
ii. Total bilirubin > upper limit of normal (ULN) and direct bilirubin = 0.5 mg/dL
iii. Alkaline phosphatase (ALP) > 2.0 x ULN
iv. Alanine aminotransferase (ALT) > 1.5 x ULN
v. Aspartate aminotransferase (AST) > 1.5 x ULN
vi. Platelet count < 100 x 109/L
10. Current or history of systemic intravenous (IV) or oral immunomodulatory agents, or biologics or steroid use in the past 6 months prior to consent (topical and inhaled treatment are allowed, [e.g., for asthma or eczema]). Occasional use of systemic steroid may be allowed based on discussion and agreement with the Medical Monitor.
11. Contraindication to use of corticosteroids (including but not limited to uncontrolled glaucoma, diabetes mellitus or hypertension)
12. History of malignancy, except for non-melanoma skin cancer and localized prostate cancer treated with curative intent
13. Recent history of alcohol or substance abuse. The use of marijuana may be considered on an individual basis with discussion and agreement from the Medical Monitor.
14. Participation in prior investigational interventional drug or medical device study throughout the duration of this study and within the last 3 months prior to consent (with the exception of implantable loop recorders as in the RaILRoAD trial)
15. Prior treatment with a gene therapy product
16. Known hypersensitivity to components of ST-920 formulation
17. Any other reason that, in the opinion of the Site Investigator or Medical Monitor, would render the subject unsuitable for participation in the study, including but not limited to risk of COVID-19 infection
18. Females
Additional exclusion criteria for:
Cohorts 1-4 and renal cohort:
19. Subjects who meet New York Heart Association (NYHA) Class III and IV
Renal cohort:
20. History of renal dialysis or transplantation
21. History of acute kidney insufficiency in the 6 months prior to screening
22. Angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) therapy initiated within 4 weeks prior to screening or changed ACE inhibitor or ARB dose in the 4 weeks prior to screening
23. Urine protein to creatinine ratio (UPCR) >0.5 g/g who are not being treated with an AC

Study & Design

• Study Type: Interventional clinical trial of medicinal product
• Study Design: Not specified