According to a Citi Research note to investors published today, April 23rd, the FDA has decided to be more flexible regarding the kind of data it will allow companies to submit in their applications for accelerated approval of drugs. Citi analysts Yaron Werber and Kumaraguru Raja say this change of heart by the FDA is good news for both Sarepta Therapeutics Inc (NASDAQ:SRPT) and Prosensa Holding NV (NASDAQ:RNA), and gives both companies a path forward toward approval of their muscular dystrophy therapeutics.

FDA willing to accept data on a rolling basis

The key change in FDA policy here is that the agency is now willing to be more flexible in accepting the delivery of data for the clinical trials it requires companies to make to prove their drugs are safe and effective. This additional flexibility by the FDA could reduce potentially reduce clinical development timelines by as much as 18 to 24 months.

Citi on Sarepta

Sarepta FDA

The Citi report suggests the outlook for eteplirsen is much improved as the decision by FDA offers an earlier than expected path to commercialization with potential approval in the second half of 2015. However, Werber and Raja point out the FDA is obviously not comfortable approving eteplirsen with the current data, and the final decision on approval will largely relate to the FDA’s take on the Ph2 extension data from weeks 144 through 168, the data from fourth biopsy, the agency’s thoughts on the methods and analysis used with the dystrophin data as well as safety data from the confirmatory trial. Citi rates Sarepta Therapeutics Inc (NASDAQ:SRPT) as Neutral and does not have a current price target on the stock.

Sarepta FDA 2

Citi on Prosensa

The Citi analysts also highlight that this news puts Prosensa Holding NV (NASDAQ:RNA)’s drisapersen back in the running, as the company should also be able to file with the FDA on their existing Ph2 and Ph3 data involving more than 300 patients. The report notes that Prosensa is in ongoing discussions with both EMA and FDA. The company has announced it hopes to start re-dosing patients in the first cohort by the third quarter of this year.

Werber and Raja summarize their take on Prosensa Holding NV (NASDAQ:RNA): “We expect that there is a possibility that Prosensa will re-file in Q4:14 with approval in Q3:15. Once Prosensa starts re-dosing then Sarepta will have to compete for the some of the same patients. In comparison to Sarepta Therapeutics Inc (NASDAQ:SRPT), Prosensa’s stock is cheaper despite its freedom to operate globally for exon51 and being ahead of Sarepta in other exon segments. Prosensa has more data and we expect it to get clarity in Q2 and we note that we see a lot of upside if the FDA is supportive of early filing.”