SAN RAFAEL, Calif. (TheStreet) -- BioMarin Pharmaceuticals (BMRN) is expanding its reach into the market for rare-disease therapies with a deal to buy Prosensa Holding (RNA) for up to $840 million, the companies said Monday.
The deal is a gamble of sorts for BioMarin, which is betting that its experience and expertise in securing approvals for so-called orphan-disease drugs can help Prosensa win approval for drisapersen, an experimental treatment for Duchenne muscular dystrophy, despite mixed results from clinical trials.
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Prosensa is being acquired for $17.75 a share, which represents a 55% premium to the stock's closing price on Friday. The upfront portion of the deal is valued at $680 million.
BioMarin will pay an additional $160 million to Prosensa in two separate transactions if drisapersen is approved in Europe and the U.S.
"BioMarin is dedicated to the rare-disease community, and the acquisition of Prosensa fits strategically with our mission of delivering therapies that address serious unmet medical needs," BioMarin Chief Executive Jean-Jacques Bienaime said in a statement. "We will leverage our experience at developing rare-disease therapies to achieve regulatory approvals and bring drisapersen to market as quickly as possible."
Prosensa is expected to complete the submission of drisapersen clinical data to the Food and Drug Administration in the first quarter, which could lead to an FDA approval decision in the middle of the year. The FDA is also also widely expected to convene an advisory panel meeting to review the drisapersen data.
The drisapersen review is likely to be contentious.
A phase III study in DMD patients failed to demonstrate that drisapersen could improve walking ability compared to a placebo. Prosensa asserts that certain subgroups of DMD patients benefit from drisapersen in the phase III study, supported by more positive data from older, phase II studies.
Meanwhile, Sarepta Therapeutics (SRPT) is also developing a drug known as eteplirsen to treat DMD patients, but its FDA approval application isn't expected to be completed until the middle of next year. Sarepta's delayed filing opens the door for Prosensa and now BioMarin to secure approval first.
BioMarin shares closed Friday at $85.83.