Shares of Prosensa Holdings NV (RNA) surged as much as 50% after it announced this morning that it would be acquired by Biomarin (BMRN) for approximately $840 million. The deal will be split up in certain parts depending on certain milestones reached. For instance, the initial payment to shareholders for Prosensa will be $680 million, or about $17.75 per share. The shareholders for Prosensa will have the ability to obtain $80 million if Drisapersen receives U.S. FDA approval before May 2016 and an additional $80 million if Drisapersen is approved in Europe before February 2017.
Drisapersen is a drug that is being developed for a rare disease known as Duchenne muscular dystrophy in which the patients suffers muscle weakness over time and eventually worsen as the years progress. The disease is inherited and by the age of 12 boys are no longer able to walk any type of distance. Prosensa, like Sarepta Therapeutics (SRPT), has been working with the FDA to get its drugs approved to help these patients with Duchenne muscular dystrophy. Both companies have recently suffered hardships as the FDA is not clear on whether or not dystrophin — which the muscles need for movement — is a great measurement to determine efficacy of Drisapersen and Sarepta’s drug Eteplirsen. Sarepta suffered a setback with their Eteplirsen drug as the FDA is set to meet with the company and may demand more data before it can approve it for these patients who desperately need a treatment.
Unlike Sarepta only doing a small phase 2 study with only 12 patients enrolled, Prosensa has established its clinical data treating over 300 patients with Drisapersen. Therefore Prosensa does have the upper hand since they have more data to show the FDA for U.S. approval. The Drisapersen drug was granted Fast Track Status from the FDA, which allows for a rolling review. That means Prosensa would be allowed to submit its NDA — New Drug Application — to the FDA in parts over a period of time instead of having to wait to file for U.S. approval. The drug also had received “breakthrough therapy designation” which allows for quicker review by the FDA for approval.
