Japan drugmaker pursues hostile takeover of OSI

Melville-based OSI Pharmaceuticals Inc. was under increasing pressure from shareholders as a Japanese drugmaker Tuesday began the formal process of a hostile takeover.

Shares of OSI soared more than 40 percent from a Friday close of $37 on news that Astellas Pharma Inc., a global pharmaceutical manufacturer, would offer $52 a share and would go directly to shareholders. Its earlier proposals to the OSI board were rejected. OSI, whose research focuses on drugs for cancer and diabetes, is in the process of moving to Westchester County.

Astellas subsidiary Ruby Acquisition Inc. Tuesday morning made the official offer of $52 cash for the shares, but by the time markets opened the stock was already trading at $57 on expectations that the Astellas offer would increase.

Another subsidiary, Astellas U.S. Holding Inc., also took action, announcing Tuesday that it had filed a lawsuit in Delaware against OSI and its directors to prevent them from obstructing the attempted takeover.

The board of directors of OSI responded Tuesday by issuing a news release asking shareholders to "take no action at this time pending the review of the tender offer."