Astellas Pharma buys OSI for $4 billion

Astellas Pharma Inc., Japan’s No. 2 drug maker, said Monday it will buy U.S. cancer drug company OSI Pharmaceuticals Inc. for $4 billion in cash in a bid to expand its cancer drug business worldwide.

Astellas said it will pay $57.50 per OSI share, up from $52 the Japanese company had offered earlier. The transaction will be completed within a month.