Sangamo Therapeutics has identified a shortcut to market for its Fabry disease candidate, aligning with the FDA on a pathway that could slash three years from the time to market and free it from the need to run an additional registrational study. Shares in Sangamo jumped 33% to $1.22 in the wake of the news.
The biotech pumped the brakes on the Fabry gene therapy, ST-920, almost 12 months ago. At that time, Sangamo decided to defer investments in phase 3 planning until it had secured funding or a partner. The biotech is yet to land a partner—but has now established a route to a submission for FDA approval in the second half of 2025.
Sangamo previously provided an update on the program in February, at which time it shared the FDA’s view that a single trial with up to 25 patients, plus confirmatory evidence, may be acceptable. The latest statement firms up the plans for bringing ST-920 to market.
The FDA will allow an ongoing phase 1/2 study to serve as the primary basis for accelerated approval, the biotech said, and will accept eGFR slope, a surrogate for kidney health, at 52 weeks as an intermediate clinical endpoint. Sangamo said the agency also advised that eGFR slope at 104 weeks may be assessed to verify clinical benefit.
Sangamo has finished enrollment in the trial, which has dosed 33 patients, and expects to have the data to support a submission in the first half of 2025. The filing is planned for the second half of next year.
The biotech engaged with the FDA on alternative pathways to approval after seeing safety and efficacy data from the phase 1/2 trial. Sangamo reported statistically significant improvements in both mean and median eGFR levels, resulting in a positive annualized eGFR slope.
Buoyed by the feedback, Sangamo has begun laying the groundwork for a filing for accelerated approval while continuing talks with potential partners. Sangamo CEO Alexander Macrae fielded a question about why he had yet to seal a deal for ST-920 on an earnings call in August. Macrae said he wants “to do the right deal, not a quick deal” and that cash from Genentech gave Sangamo time to find the right partner.
Getting alignment with the FDA on the path to market could strengthen Sangamo’s hand in its search for a partner for ST-920. The adeno-associated virus gene therapy is designed to equip patients to produce the lysosomal enzyme alpha galactosidase A. Currently, people take enzyme replacement therapies such as Sanofi’s Fabrazyme to manage Fabry.