Prosensa's Stock Soars After Buyout Deal With BioMarin

Prosensa Holding's U.S-listed shares soared 63% in premarket trade Monday, after Dutch biotechnology company agreed to be acquired by BioMarin Pharmaceutical in a deal valued at $680 million. The per-share bid of $17.75 represents a 55% premium to Friday's closing price of $11.44. The deal also includes two potential milestone payments of $80 million, payable if Prosensa's muscular dystrophy treatment drisapersen is approved in the U.S. no later than May 15, 2016, and in Europe no later than Feb. 15, 2017. BioMarin's stock was still inactive ahead of Monday's open. Prosensa's stock has more than doubled so far this year through Friday, while BioMarin's had climbed 22% and the S&P 500 had gained 12%.