Shares of Sarepta Therapeutics (SRPT +13.3%) jump on increased volume after FDA Center for Drug Evaluation and Research chief Janet Woodcock stated that the agency is exploring all "potential pathways" to approve new drugs to treat Duchenne muscular dystrophy. She also specifically mentioned the possibility that agency would place Sarepta's eteplirsen in its accelerated approval program.
SRPT longs have had a rough ride since the October 7, 2013 peak of $55.61. Shares cratered to a low of $12.12 on November 11 after the FDA said that the company's NDA was premature due to a perceived lack of efficacy of the dystrophin biomarker. Shares climbed back to $40.00 on April 21, 2014 before dropping again.
Shares of Sarepta Therapeutics (SRPT) are down 14% premarket on robust volume in response to the company's clinical update on eteplirsen in patients with Duchenne muscular dystrophy. At week 144, the decline in walking ability was greater than the decline measured at 74 weeks implying that the drug's effectiveness may be declining. The average decline in walking ability as measured by the 6-minute walk test (6MWT) was 2.2 meters at 74 weeks compared to an average decline of 33.2 meters (n=6) at 144 weeks.
SRPT longs have had quite a bit of excitement since Q4 of last year. Shares peaked at $55.61 on October 7 and bottomed at $12.12 on November 13. Prices rebounded to $40 by April 21 only to retreat and start another down trend.
PTC Therapeutics (PTCT) +119.2% premarket after the Committee for Medicinal Products for Human Use of the European Medicines Agency issues a positive opinion on PTCT's application for a conditional marketing authorization of its Ataluren muscular dystrophy treatment.
The news is a major upside surprise: Credit Suisse says a potential early EU approval for Ataluren has not been priced in to shares.
Others involved in Duchenne muscular dystrophy treatments also trade higher premarket: RNA +16%, SRPT +3%.
Based on updated guidance from the FDA regarding an early approval pathway for eteplirsen, Sarepta Therapeutics (SRPT) plans to file an NDA by the end of 2014.
The agency provided specific examples of additional safety and efficacy data for Duchenne muscular dystrophy that would enhance the acceptability of the NDA. The company will conduct several open label confirmatory studies later this year on patients with exon-51 amenable genotypes.
The company plans to conduct three studies: 1) ambulatory patients between the ages 7 and 16 years who can walk a minimum distance, 2) patients younger than 7 years, 3) DMD patients who cannot walk a minimum distance or who are non-ambulant.
The firm also plans to start a placebo-controlled study with one or more if its follow-on DMD exon-skipping drug candidates by year end.
JMP's Liisa A. Bayko has downgraded Sarepta (SRPT -5.1%) to Market Perform a week after shares flew higher with the help of a clinical data update from Prosensa (RNA -2.3%) on the performance of its Drisapersen drug, which (like Sarepta's Eteplirsen) aims to treat duchenne muscular dystrophy (DMD).
Bayko calls Prosensa's data "weak," and thinks investors may be overvaluing its positive implications for Sarepta. She also thinks "the FDA could request a second study from Prosensa, putting further pressure on the already scarce patient population available for clinical trials."
Though still considering Eteplirsen "a best-in-class drug that will eventually be approved [to treat] DMD," Bayko is worried about the lengthy amount of time expected to obtain "pivotal data and approval," as well as a lack of near-term catalysts.