Astellas purchases OSI

Japanese company Astellas Pharma has announced that it has completed the acquisition of US biotech, OSI Pharmaceuticals

Japan's second largest pharma company, Astellas Pharma, has announced that it has completed the acquisition of US biotech OSI Pharmaceuticals through a short-form merger.

In the deal, valued at $4bn, each outstanding share of OSI common stock not purchased in Astellas' tender offer, or otherwise owned by Astellas, was converted into the right to receive the same amount of $57.50. This is 11 per cent more than a previously proposed $52 per share.

OSI is now a wholly-owned subsidiary of Astellas US Holdings, which is owned by Astellas Pharma. The acquisition marks the completion of a hostile takeover bid launched in March this year after Astellas originally initiated talks with OSI in early 2009 and adds cancer blockbuster, Tarceva (erlotinib) to Astellas' portfolio.

Masafumi Nogimori, president and CEO of Astellas, said: "This compelling transaction marks an important step forward for Astellas as the company works towards developing a world-class oncology platform."

OSI is a biotechnology company focused on the discovery, development and commercialisation of molecular targeted therapies addressing medical needs in oncology, diabetes and obesity. Tarceva is the company's lead cancer drug, with several other drug prospects in the R&D pipeline.

The purchase of OSI will bolster Astellas' existing interests in urology and transplantation as its urinary drug, Flomax (tamsulosin), and transplant drug, Prograf (tacrolimus), recently lost patent protection in the US and face generic competition.

It also takes Astellas into the US market after its hostile bid for CV Therapeutics failed last year.