Astellas completes acquisition of OSI

TOKYO Japanese drug maker Astellas Pharma has completed its acquisition of OSI Pharmaceuticals, Astellas said Tuesday.

The $4 billion acquisition, announced in May, gives Astellas access to such drugs as the cancer drug Tarceva (erlotinib), which OSI co-markets with Roche division Genentech. OSI has lately been enrolling subjects for a late-stage clinical trial of OSI-906, a treatment for patients with adrenocortical carcinoma, a rare cancer of the adrenal gland, whose disease has spread to other parts of the body.

OSI will become a wholly owned subsidiary of Astellas through Astellas US Holding, a holding company.