Shares of Prosensa (UNKNOWN:RNA.DL), a biotech company developing the drug drisapersen for the treatment of Duchenne muscular dystrophy, or DMD), plunged 70% today after the company revealed that the drug failed to reach its goal in a late-stage clinical trial. The market valuation for Prosensa, which went public over the summer, plummeted on this news, while shares of its partner GlaxoSmithKline (NYSE:GSK) were not affected. Shares of its rival Sarepta (NASDAQ:SRPT), however, have fluctuated throughout the day. Opinions differ on how this will affect the road to approval for Sarepta's eteplirsen, a competing experimental DMD medication. Analyst Max Macaluso discusses this news and its impact on all three players in the following video.

Editor's note: At the time of this video, shares of Sarepta were up only 2%. The stock is now up 17% intraday.

Max Macaluso, Ph.D. owns shares of Sarepta Therapeutics. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.