Astellas Offers $3.5 Billion For OSI Pharmaceuticals By: MarketMinute.com Stock News March 01, 2010 at 11:48 AM EST Japan's second largest drugmaker Astellas made an unsolicited $3.5 billion hostile bid for OSI Pharmaceuticals Inc. (Nasdaq: OSIP) sending the stock price soaring $19.46 to $56.48.