Sarepta Therapeutics’ shares saw a nice boost early Friday morning as the biotech declared its intent to seek an early accelerated approval for the Roche-partnered Duchenne muscular dystrophy (DMD) gene transfer therapy SRP-9001.
The stock was trading up 11% as the market opened to $95.20, compared to a close of $85.93. The therapy has a history of making an impact on Sarepta’s shares; in January, when the company announced that an accelerated review filing would take place in 2023, the shares dropped 15% to $72.20.
But SRP-9001 will be headed for an accelerated approval filing this fall instead, an acceleration of Sarepta’s original plan. CEO Doug Ingram said the application is being submitted in the fall after the company received feedback, presumably from the FDA, and “following a thorough and in-depth review.” The regulatory process is expected to commence this year and run through the first half of 2023.
Ingram noted the swift-moving, devastating disease and said Sarepta is proceeding “with the urgency desperately needed” by patients.
SRP-9001 is a gene therapy designed to deliver the microdystrophin-encoding gene into muscle tissue to prompt production of the microdystrophin protein. Patients with DMD have a mutation in the DMD gene and can’t make the protein on their own, leading to a progressive loss of muscle strength.
Sarepta presented data from several SRP-9001 studies in progress earlier this month, including the phase 1 ENDEAVOR trial, or Study 103. The one-year results showed an improvement in functional motor abilities in ambulant children at 52 weeks following treatment compared to a control data set made up of previous DMD trial results and a natural history study of likely outcomes for these patients. Sarepta said the results show that patients treated with SRP-9001 had a clinically meaningful benefit compared to how the degenerative disease typically progresses.
Ingram noted at the time that Sarepta now has positive results for the gene therapy at one, two and four years after treatment, which also shows a consistent safety profile.
A phase 3 trial called EMBARK is underway in 120 patients aged four to seven. This trial has a similar main endpoint to the recent readout from ENDEAVOR, a rating of improvement in functional motor abilities at 52 weeks, but compared to placebo.
The phase 3 study made news in October 2021 when Sarepta reported a case of muscle weakness in a trial participant. The company banded together with other DMD gene therapy makers Pfizer, Genethon and Solid Biosciences to get to the bottom of the adverse events that were cropping up across different treatments and studies. The companies put together a panel of experts to examine the safety data, finding that the events were tied to a “class effect,” or some sort of T-cell-mediated immune response experienced by certain patients.
SRP-9001 was previously granted fast-track and rare pediatric disease designations from the FDA along with orphan drug status in the U.S., the EU, Switzerland and Japan.