D-Day For Sarepta As FDA Decision Looms

(RTTNews) - After being voted down by an FDA panel last month, Sarepta Therapeutics Inc.'s (SRPT) Duchenne Muscular Dystrophy drug candidate Eteplirsen awaits the regulatory agency's final decision, which is set for May 26, 2016.

Duchenne Muscular Dystrophy, or DMD in short, is a rare genetic muscle-wasting disease caused by the absence of dystrophin, a protein necessary for muscle function. DMD usually affects boys, and its prevalence is roughly 1 in every 3,500 - 5,000 boys worldwide. Children affected by DMD lose their ability to walk and they will be confined to wheelchairs by late childhood.

Sarepta is seeking approval of Eteplirsen for Duchenne Muscular Dystrophy amenable to exon 51 skipping.

Eteplirsen is designed to work by skipping exon 51 in the dystrophin gene to correct for specific genetic mutations and restore the gene's ability to make a functional, though shorter, form of the dystrophin protein. Approximately 13% of people with DMD are estimated to have a mutation targeted by Eteplirsen.

There is currently no approved therapy in the United States for DMD. However, there is one marketed drug in the European Union - PTC Therapeutics Inc.'s (PTCT) Translarna - which was given conditional approval by the European Medicines Agency in 2014 for the treatment of nonsense mutation Duchenne muscular dystrophy. The annual cost of Translarna treatment per patient is about £400,000, according to reports.

PTC Therapeutics is also seeking approval of Translarna in the U.S. In February of this year, the FDA refused to accept the NDA for Translarna for review, stating that the application was not sufficiently complete to permit a substantive review.

Although the phase III trial results showed clinically meaningful benefits for Translarna-treated patients, the primary endpoint of change from baseline in the 6-minute walk test was not statistically significant.

Ever since the phase III results of Translarna were released in February of this year, experts have been wondering about the future of the drug in the EU. It remains to be seen when the conditional approval granted to Translarna by the EMA will be converted to a full approval.

BioMarin Pharmaceutical Inc. (BMRN) and Santhera Pharmaceuticals Holding AG, which trades on the SIX Swiss Exchange, are the other companies that are involved in developing therapies for the treatment of Duchenne Muscular Dystrophy.

BioMarin's DMD drug candidate Kyndrisa also works by the same mechanism as that of Sarepta's Eteplirsen by inducing the skipping of dystrophin exon 51. Kyndrisa was snubbed by the FDA early this year, and in its Complete Response Letter, issued on January 14, 2016, the regulatory agency had concluded that the standard of substantial evidence of effectiveness was not met by Kyndrisa.

Kyndrisa is under review in the European Union, and a regulatory decision is expected in the second half of 2016.

Santhera Pharmaceuticals' DMD drug candidate is known as Raxone (Idebenone). The company reported positive results from a phase III trial of Raxone in patients with Duchenne Muscular Dystrophy in May 2014. Preparations are underway to make regulatory filings for Raxone in DMD in the U.S. and EU.

For now, all eyes are on Sarepta and its DMD drug candidate Eteplirsen. Will Eteplirsen get the much need FDA approval or will it be sent back to the drawing board? Stay tuned for our next update...

SRPT closed Tuesday's trading at $18.44, up 5.49%. The stock has traded in a range of $8.00 to $41.97 in the last 1 year.