isaralgagene civaparvovec (ST 920) / PTC Therapeutics - LARVOL DELTA

PTC Therapeutics…announced today it completed its acquisition of ST-920, a gene therapy for Fabry disease, from Sangamo Therapeutics, Inc. (Investing.com) - "The company expects to complete a rolling Biologics License Application submission to the FDA for accelerated approval of ST-920 in the fourth quarter of 2026, according to a press release statement. ST-920, also known as isaralgagene civaparvovec, is a one-time administered AAV gene therapy designed to treat Fabry disease."

FDA filing • M&A • Fabry Disease

Long-Term Follow-up of Subjects Who Were Treated With ST-920 (clinicaltrials.gov) - P=N/A | N=32 | Active, not recruiting | Sponsor: Sangamo Therapeutics | Enrolling by invitation ➔ Active, not recruiting | N=48 ➔ 32

Enrollment change • Enrollment closed • Fabry Disease • Gene Therapies • Genetic Disorders

PTC Therapeutics…announced that it was selected as the winning bidder to acquire ST-920 - a BLA-stage one-time administered AAV gene therapy for Fabry disease - from Sangamo Therapeutics in a competitive bankruptcy auction (PRNewswire) - "The terms include $111 million upfront and up to $100 million in contingent milestone payments based on certain regulatory approvals. A rolling BLA submission to FDA for accelerated approval of ST-920 is expected to be completed in Q4 2026...with potential for commercial launch in 2027....The BLA is based on evidence of meaningful favorable clinical effect on renal function and safety and tolerability profile over 52 weeks in the Phase 1/2 STAAR study."

FDA filing • Launch US • M&A • Fabry Disease

nAbCyte Anti-AAV6 FD-IC Assay for detection of neutralizing antibodies to adeno-associated virus: analytical validation (ASGCT 2026) - "Long-term reagent and sample stability studies are ongoing. Conclusion Analytical validation testing demonstrated the precision, sensitivity, accuracy, specificity of the nAbCyte Assay, supporting use as an in vitro companion diagnostic test to aid in selection of FD patients that are favorable candidates for ST-920 gene therapy."

Fabry Disease • Gene Therapies • Genetic Disorders • Lysosomal Storage Diseases • Metabolic Disorders • Rare Diseases • GLA

Long-Term Follow-up of Subjects Who Were Treated With ST-920 (clinicaltrials.gov) - P1/2 | N=48 | Enrolling by invitation | Sponsor: Sangamo Therapeutics | Phase classification: P ➔ P1/2

Phase classification • Fabry Disease • Gene Therapies • Genetic Disorders

Sangamo Therapeutics Initiates Rolling Submission of BLA to U.S. FDA for ST-920 in Fabry Disease (The Manila Times) - "Sangamo expects to complete Biological License Application (BLA) submission under accelerated approval pathway in second quarter of 2026...'The compelling data from our STAAR study shows the potential of ST-920 to provide safe and long-lasting clinical benefits to a wide range of Fabry disease patients.'"

FDA filing • Fabry Disease

Sangamo Therapeutics Announces FDA Acceptance of BLA Rolling Submission Request for ST-920 in Fabry Disease (The Manila Times) - "This acceptance follows Sangamo’s meeting with the FDA in October 2025 to discuss the proposed efficacy and safety data package for isaralgagene civaparvovec....Sangamo plans to initiate rolling submission of the BLA to the FDA under the accelerated approval pathway later in the fourth quarter of 2025."

FDA filing • Fabry Disease

Dose-Ranging Study of ST-920, an AAV2/6 Human Alpha Galactosidase A Gene Therapy in Subjects With Fabry Disease (STAAR) (clinicaltrials.gov) - P1/2 | N=33 | Completed | Sponsor: Sangamo Therapeutics | Active, not recruiting ➔ Completed | Trial completion date: Sep 2025 ➔ Apr 2025

Trial completion • Trial completion date • Fabry Disease • Gene Therapies • Genetic Disorders

Sangamo Therapeutics Announces Important Derisking Milestones in Pathway to Anticipated BLA Submission for ST-920 in Fabry Disease (Businesswire) - "Sangamo Therapeutics, Inc...announced important derisking events in the pathway to a planned BLA submission for isaralgagene civaparvovec, or ST-920, its wholly owned gene therapy product candidate for the treatment of Fabry disease...All dosed patients in the Phase 1/2 STAAR study evaluating isaralgagene civaparvovec have now completed at least 52-weeks of follow-up, a key milestone required by the FDA for an Accelerated Approval regulatory pathway for ST-920....A pivotal data readout is expected by the end of the second quarter of 2025....This BLA submission timeline would facilitate a potential approval and commercial launch as early as the second half of 2026."

FDA approval • Launch US • P1/2 data • Trial status • Fabry Disease

Sangamo Therapeutics Reports Recent Business Highlights and Fourth Quarter and Full Year 2024 Financial Results (Businesswire) - "Recent Business Highlights:...Enrollment and dosing are complete in the Phase 1/2 STAAR study. The FDA has provided a clear regulatory pathway to Accelerated Approval for isaralgagene civaparvovec, agreeing that data from the ongoing Phase 1/2 STAAR study can serve as the primary basis for approval under the Accelerated Approval Program, using eGFR slope at 52 weeks across all patients as an intermediate clinical endpoint. The 52-week eGFR slope data from all enrolled patients in the Phase 1/2 STAAR study will be available in the first half of 2025. A potential Biologics License Application (BLA) submission is anticipated in the second half of 2025."

FDA filing • P1/2 data • Trial status • Fabry Disease

Long-Term Follow-up of Subjects Who Were Treated with ST-920 (clinicaltrials.gov) - P=N/A | N=48 | Enrolling by invitation | Sponsor: Sangamo Therapeutics | Trial completion date: Jun 2029 ➔ Mar 2039 | Trial primary completion date: Jun 2028 ➔ Mar 2029

Trial completion date • Trial primary completion date • Fabry Disease • Gene Therapies • Genetic Disorders

Sangamo Therapeutics Announces Alignment With FDA on Accelerated Approval Pathway for ST-920 in Fabry Disease With BLA Submission Expected in 2025 (Businesswire) - "Sangamo Therapeutics, Inc...announced the outcome of a recent successful interaction with the U.S. FDA, providing a clear regulatory pathway to Accelerated Approval for isaralgagene civaparvovec, or ST-920, its wholly owned gene therapy product candidate for the treatment of Fabry disease....The complete dataset to support an Accelerated Approval pathway will be available in the first half of 2025. This approach unlocks a potential BLA submission in the second half of 2025...The 52-week eGFR slope data from all enrolled patients in the Phase 1/2 STAAR study will be available in the first half of 2025. A potential BLA submission is anticipated in the second half of 2025."

FDA filing • P1/2 data • Fabry Disease • Genetic Disorders

Dose-Ranging Study of ST-920, an AAV2/6 Human Alpha Galactosidase A Gene Therapy in Subjects With Fabry Disease (STAAR) (clinicaltrials.gov) - P1/2 | N=34 | Active, not recruiting | Sponsor: Sangamo Therapeutics | Recruiting ➔ Active, not recruiting | Trial completion date: Feb 2024 ➔ Sep 2025 | Trial primary completion date: Dec 2023 ➔ Apr 2025

Enrollment closed • Gene therapy • Trial completion date • Trial primary completion date • Fabry Disease • Gene Therapies • Genetic Disorders

Sangamo Therapeutics Receives U.S. FDA Fast Track Designation for Isaralgagene Civaparvovec for the Treatment of Fabry Disease (Businesswire) - "Sangamo Therapeutics, Inc...announced that the U.S. Food and Drug Administration (FDA) has granted Fast Track Designation to isaralgagene civaparvovec, or ST-920, a wholly owned gene therapy product candidate for the treatment of Fabry disease."

Fast track designation • Fabry Disease • Genetic Disorders

Sangamo Therapeutics Announces Strategic Update and Reports Preliminary First Quarter 2023 Financial Results (Businesswire) - "Dosed three additional patients in the dose expansion phase of the Phase 1/2 STAAR study evaluating isaralgagene civaparvovec, our wholly owned gene therapy product for the treatment of Fabry disease, for a total of 20 patients dosed to date. We expect dosing to conclude by the end of 2023. Plan to meet with the FDA on proposed Phase 3 study design in the summer and anticipate commencement of the pivotal trial in the second half of 2023, with dosing of the first patient expected to start as early as the first part of 2024."

Clinical protocol • P1/2 data • Trial status • Fabry Disease • Genetic Disorders

Preliminary results of STAAR, a Phase I/II study of isaralgagene civaparvovec (ST-920) gene therapy in adults with Fabry disease and long-term follow-up (ESGCT 2022) - No abstract available

Clinical • P1/2 data • Fabry Disease • Gene Therapies • Genetic Disorders

Long-Term Follow-up of Subjects Who Were Treated With ST-920 (clinicaltrials.gov) - P; N=48; Enrolling by invitation; Sponsor: Sangamo Therapeutics

Clinical • New trial • Fabry Disease • Gene Therapies • Genetic Disorders

Dose-Ranging Study of ST-920, an AAV2/6 Human Alpha Galactosidase A Gene Therapy in Subjects With Fabry Disease (clinicaltrials.gov) - P1/2; N=48; Recruiting; Sponsor: Sangamo Therapeutics; N=30 ➔ 48; Trial completion date: Nov 2021 ➔ Feb 2024; Trial primary completion date: Sep 2021 ➔ Dec 2023

Clinical • Enrollment change • Trial completion date • Trial primary completion date • Fabry Disease • Gene Therapies

AAV2/6 Gene Therapy in a Murine Model of Fabry Disease Results in Supraphysiological Enzyme Activity and Effective Substrate Reduction. (PubMed, Mol Ther Methods Clin Dev) - "Further optimization of vector design identified the clinical lead vector, ST-920, which produced several-fold higher plasma and tissue α-Gal A activity levels with a good safety profile. Together, these studies provide the basis for the clinical development of ST-920."

Journal • Preclinical • CNS Disorders • Fabry Disease • Gene Therapies • Genetic Disorders • Lysosomal Storage Diseases • Rare Diseases

Dose-Ranging Study of ST-920, a rAAV2/6 Human Alpha Galactosidase A Gene Therapy in Subjects With Fabry Disease (clinicaltrials.gov) - P1/2; N=30; Recruiting; Sponsor: Sangamo Therapeutics; N=18 ➔ 30

Clinical • Enrollment change

Dose-Ranging Study of ST-920, a rAAV2/6 Human Alpha Galactosidase A Gene Therapy in Subjects With Fabry Disease (clinicaltrials.gov) - P1/2; N=18; Recruiting; Sponsor: Sangamo Therapeutics

Clinical • New P1/2 trial

Liver-Targeted AAV Gene Therapy Vectors Produced at Clinical Scale Result in High, Continuous Therapeutic Levels of α-GalA Enzyme Activity and Effective Substrate Reduction in a Mouse Model of Fabry Disease (ASGCT 2019) - "...This initial AAV-hGLA vector was compared to an improved vector, designated ST-920, containing an additional regulatory element in the non-coding sequence...The high levels of ?-GalA activity seen in these studies, along with the concomitant marked reduction in the accumulated Gb3/lyso-Gb3 in key tissues of the GLAKO mouse model, provide preclinical proof-of-concept for AAV-mediated targeting of hepatocytes to express therapeutic levels of human ?-GalA. The clinical scale manufacturing process developed for these studies will enable rapid production of clinical-grade AAV material."