The good news for Sarepta Therapeutics Inc. is bad news for Pfizer Inc. as the phase III study of its mini-dystrophin gene therapy in Duchenne muscular dystrophy (DMD) has missed its primary endpoint. Now Sarepta’s Elevidys (delandistrogene moxeparvovec), a single-dose, adeno-associated virus-based gene transfer therapy for DMD, is barreling toward a June 21 PDUFA date with the U.S. FDA as the near competition shrinks in the rearview mirror.
Shares of Dyne Therapeutics Inc. (NASDAQ:DYN) closed May 20 at $35.38, up $7.70, or 28%, on word of positive data from the phase I/II Achieve trial of DYNE-101 in myotonic dystrophy type 1 (DM1) and the phase I/II Deliver effort with DYNE-251 in Duchenne muscular dystrophy (DMD) who are amenable to exon 51 skipping. CEO John Cox, who joined Waltham, Mass.-based Dyne eight weeks ago, said he “couldn’t be more proud to be part of this team.” Studies are ongoing, but new data with regard to DM1 as well as DMD showed a “compelling” impact, Dyne said, plus satisfying safety profiles.
With positive initial phase I/II data in hand from two trials, Dyne Therapeutics Inc. plans to report more findings and start enrolling registrational cohorts in both studies by the end of this year for DYNE-101 in myotonic dystrophy type 1 (DM1) and a study called Deliver with DYNE-251 in Duchenne muscular dystrophy (DMD) who are amenable to exon 51 skipping.
The FDA clapped a clinical hold on the IND for a clinical trial of Dyne Therapeutics Inc.’s DYNE-251 for treating Duchenne muscular dystrophy in patients amenable to skipping exon 51. The agency is asking for more clinical and non-clinical information on the therapy. A response, including data from existing and ongoing studies in the second quarter of 2022, is expected to be filed to the FDA sometime in mid-2022, Dyne said.
Sarepta Therapeutics Inc.’s miss on a key phase II ambulatory endpoint in its Duchenne muscular dystrophy (DMD) trial may have been caused by a dramatic disparity in functional ability at baseline among older vs. younger patients afflicted with the progressively worsening disorder. In any case, Wall Street had knives out, carving 51% of the value away from shares (NASDAQ:SRPT) of the Cambridge, Mass.-based firm, which closed at $82.29, a loss of $86.66, or 51%.
