Sarepta won't need FDA adcomm, boosting Duchenne gene therapy's odds
On its quest to get the first gene therapy for Duchenne muscular dystrophy approved by the FDA, Sarepta won’t have to face an FDA advisory committee after all.
The biotech disclosed in its quarterly update Tuesday afternoon that after a mid-cycle review of SRP-9001 with the FDA, in which it answered questions about chemistry, manufacturing and controls, the agency said it does not plan to hold an adcomm. A decision on the therapy is due by May 29.
The possibility of an adcomm has been top of mind for both the company and investors since the FDA granted priority review and set the PDUFA date for SRP-9001, which would be the fourth Duchenne drug from Sarepta to win accelerated approval based on a biomarker. When the priority review was granted in November, Sarepta said it expected an adcomm to be held.
The news that one won’t be necessary sent the stock up 20% in pre-market trading Wednesday.
The therapy works on the same concept as the three approved drugs Sarepta already has on the market — Exondys 51, Vyondys 53 and Amondys 45 — except that the trio of treatments spurs functional dystrophin production by telling the body to skip over problematic exons, or parts of the DNA.
But more than six years after its first approval, the company has yet to offer definitive evidence that the dystrophin production actually translates to clinical benefit. While confirmatory trials for the early drugs are still underway, initial data on SRP-9001 were mixed. EMBARK, the proposed confirmatory trial for the gene therapy, is fully enrolled and, according to CSO Louise Rodino-Klapac, is on track for a readout in the fourth quarter of 2023.
On a call with analysts Tuesday, CEO Doug Ingram cited the “keen interest” in the application as the reason for sharing the update, but offered few other details and said the company is still working with regulators on remaining questions.
“The division formally informed us as well at the mid-cycle meeting that they see no significant safety issues that have been identified,” he said on the call.
An intramuscular injection, SRP-9001 is designed to deliver a gene that will produce a shortened version of dystrophin, the key protein missing in Duchenne patients that leads to loss of muscle functions over time, which can often be deadly. Duchenne affects roughly 1 in 3,500 male births worldwide.
