Astellas Pharma has offered $3.5 billion in cash to buy all outstanding shares of OSI Pharmaceuticals. The unsolicited offer represents a 40% premium above OSI’s share price. Masafumi Nogimori, president and chief executive officer of Astellas, remarked, “This offer follows our attempts over the past 13 months to engage OSI in meaningful discussions. We firmly believe in the compelling strategic rationale behind the combination and the opportunity it provides to the OSI stockholde...