FDA Extends Its Review of Potential DMD Therapy, Eteplirsen, into May

Sarepta Therapeutics, a developer of RNA-targeted treatments, announced that the U.S. Food and Drug Administration (FDA) is extending by another three months its review of the company’s New Drug Application (NDA) for eteplirsen, a potential treatment for Duchenne muscular dystrophy (DMD) amenable to exon 51 skipping. A reason for the extension was recently submitted new clinical data on the drug’s effectiveness, which the FDA viewed as a “major amendment” to the NDA.

The company said it received FDA notice that the Prescription Drug User Fee Act (PDUFA) date for eteplirsen had been moved to May 26, 2016. A new date for the meeting of the Peripheral and Central Nervous System Advisory Committee, advising the FDA on the approval, had not been determined at the time of the announcement.

On Jan. 8, Sarepta submitted additional data in support of its application, including four-year clinical effectiveness data that offered additional six minute walk test (6MWT) and loss of ambulation findings in DMD patients compared to a historical control. According to the Sarepta Advisory Committee Briefing Document Addendum, a comparison of these groups in Study 201/202 was the basis for establishing eteplirsen’s effectiveness.

In a press release, Edward Kaye, Sarepta’s chief executive officer and chief medical officer, said: “While our primary goal is to bring treatment to patients with Duchenne as quickly as possible, we appreciate the efforts of the FDA to conduct a complete review of all of the data supporting our NDA and we remain committed to working closely with them throughout the remainder of the regulatory process.”

An exon 51 skipping therapy would be of use to an estimated 13 percent of DMD patients. The therapy allows for skipping of the mutated part of a gene to form a shorter, but functional, protein. Sarepta also has candidate therapies for exon 53 and exon 45 skipping in various stages of clinical development.

Eteplirsen has been granted Priority Review status by the FDA, a designation given to therapies aiming to address diseases or conditions where no adequate treatments exist. The drug candidate was also granted Rare Pediatric Disease Designation, Orphan Drug Designation, and Fast Track Status.