Sangamo Therapeutics (SGMO: NASDAQ) has announced that the FDA has agreed to a regulatory pathway to Accelerated Approval for its Fabry disease gene therapy candidate, isaralgagene civaparvovec (ST-920). This news led to a 69% surge in Sangamo's shares this past week.
Accelerated Approval Pathway for ST-920
Following a successful Type B meeting with the FDA, Sangamo can now use data from its ongoing Phase I/II STAAR trial (NCT04046224) as the primary basis for accelerated approval. The key intermediate clinical endpoint will be the rate of decline in a person’s estimated glomerular filtration rate (eGFR) over time, specifically the eGFR slope at 52 weeks across all patients.
Sangamo anticipates having a complete dataset to support this accelerated approval pathway in the first half of next year and plans to submit a Biologics License Application (BLA) in the second half of 2025. This timeline is three years ahead of previous estimates, eliminating the need for an additional registrational study to establish clinical efficacy.
"I strongly believe in the potential for ST-920 to alleviate many manifestations of Fabry disease and am delighted to have a clear regulatory pathway that could bring this treatment to patients significantly sooner than originally anticipated," said Sangamo CEO Sandy Macrae.
Financial Implications and Market Response
The accelerated pathway and potential for earlier BLA submission have been well-received by investors. Sangamo's stock jumped 33% to $1.21 on Tuesday and rose another 27% to $1.54 on Wednesday, before falling 3% to $1.49 on Thursday. This surge marks the second significant increase in Sangamo's shares this year, following positive Phase III data for their hemophilia A gene therapy candidate giroctocogene fitelparvovec with partner Pfizer (PFE: New York Stock Exchange).
Sangamo has begun readiness activities related to the upcoming BLA and is advancing business development discussions with potential collaboration partners. As of June 30, Sangamo had $27.8 million in available cash and cash equivalents, plus $50 million upfront from a neuro drug collaboration with Genentech, which is projected to fund operations into the first quarter of 2025.
Competitive Landscape and Analyst Perspectives
Despite the positive news, some analysts remain cautious, emphasizing the competitive strength of Amicus Therapeutics' (FOLD: NASDAQ) Galafold® (migalastat), the only oral drug approved for Fabry disease. Other treatment options include enzyme replacement therapies like Sanofi’s Fabrazyme® (agalsidase beta) and Chiesi’s Elfabrio® (pegunigalsidase alfa-iwxj), co-developed with Protalix BioTherapeutics (PLX: NYSE American).
Jefferies analyst Dennis Ding noted, "We are not worried since Galafold is standard of care and gene therapies are reserved for late line or tough to treat patients, and the modality hasn’t demonstrated significant commercial traction yet."
Leerink Partners analyst Joseph P. Schwartz projects Galafold will generate between $442 million and $457 million in net product revenues this year, based on Amicus raising its revenue guidance.
uniQure has also entered the Fabry disease gene therapy space with AMT-191, currently in a Phase I/II trial (NCT06270316).
