Sangamo's Fabry Gene Therapy May Arrive 3 Years Sooner with FDA Fast-Track Approval

Sangamo Therapeutics has secured an agreement with the FDA to pursue accelerated approval for its investigational gene therapy for Fabry disease, isaralgagene civaparvovec. This decision, based on promising data from an ongoing Phase I/II study, could expedite the gene therapy’s market entry by three years, eliminating the need for an additional registrational study.

Sangamo shared the news on Tuesday, following a successful Type B meeting with the FDA. The regulator has agreed to use the estimated glomerular filtration rate (eGFR) slope data from the Phase I/II STAAR trial as the primary basis for seeking accelerated approval. This data serves as a surrogate marker for kidney function. The company anticipates having the necessary data to support the accelerated approval pathway by the first half of 2025 and plans to file a Biologics License Application in the latter half of the same year.

The FDA also mentioned that Sangamo could use data from an extension study that examines eGFR slope at 104 weeks to confirm the clinical benefit of the gene therapy. This pathway is expected to shorten the time-to-market significantly and bypass the requirement for another registrational study to establish clinical efficacy.

Sandy Macrae, the CEO of Sangamo, expressed his satisfaction with the clear regulatory pathway, stating that it would allow the company to bring the treatment to patients much sooner than initially expected.

Financial analysts, however, have expressed some concerns regarding the financial challenges Sangamo might face. Nicole Germino from Truist Securities emphasized the necessity for Sangamo to find a partner to advance the program to its commercial phase. Sangamo had initiated a strategic reprioritization initiative in November 2023 to concentrate its resources on genomic editing and delivery technologies. This shift led to deferred investments in its Fabry program, prompting the search for a development partner for the gene therapy.

While larger pharmaceutical companies have shown interest in rare diseases, gene therapy programs for conditions like sickle cell disease have encountered reimbursement challenges, which have impacted their uptake. On a more positive note, H.C. Wainwright analyst Patrick Trucchio highlighted that the promising data from the STAAR trial could lead to robust collaborations, potentially providing a source of non-dilutive funding for Sangamo's other programs.

Fabry disease is a rare lysosomal storage disorder resulting from the toxic buildup of the lipid globotriaosylceramide, which causes damage to vital organs including the kidneys, heart, stomach, and nerves. Patients often suffer from mood disorders, pain, kidney disease, gastrointestinal issues, and heart failure. The disease is caused by mutations in the GLA gene, leading to deficiencies in the alpha-galactosidase A enzyme. Sangamo’s gene therapy aims to deliver a functional copy of the GLA gene, allowing the liver to restore enzyme activity to healthy levels.

Germino pointed out that Sangamo would benefit from a near-term cash infusion to maximize its new pipeline focused on neurological diseases, as the licensing agreement with Roche announced in August 2024 only extends its cash runway into the first quarter of 2025. Under this agreement, Roche's Genentech paid $50 million in upfront fees and milestone payments to Sangamo to develop novel genomic medicines for neurodegenerative diseases.

Overall, the accelerated approval pathway for isaralgagene civaparvovec holds significant promise for Sangamo Therapeutics, potentially speeding up the availability of a much-needed treatment for Fabry disease. However, financial and partnership challenges remain critical for the successful commercialization of the gene therapy.