OSI Pharmaceuticals on Monday asked its shareholders to reject a $3.5 billion takeover bid from Astellas Pharma Inc.
On March 2, Astellas made the $52 per share tender offer, a 40 percent per-share premium at the time. The Japanese company also filed a lawsuit in Delaware to prevent OSI from interfering with its offer.
The OSI board of directors, however, said Astellas' offer "does not fully reflect OSI's fundamental, intrinsic value."
Astellas' offer expires March 31.
Shares of OSI Pharmaceuticals Inc. rose 32 cents to $58 in premarket trading. The stock closed at $57.68 Friday.