Sanofi-Aventis is to buy U.S. biotech TargeGen, which is developing treatments against blood diseases, for as much as $560 million as part of the French drugmaker's drive to boost its cancer treatments.

At the closing of the takeover, expected in the third quarter, Sanofi will pay $75 million and the rest will follow depending on the development of TargeGen's main product TG 101348 which aims to treat a chronic bone marrow disorder.

Privately held TargeGen, based in San Diego, Calf., develops small molecule kinase inhibitors for the treatment of certain forms of leukemia, lymphoma and other haematological malignancies and blood disorders. Sanofi has created a separate oncology unit to expand its portfolio of cancer treatments. Oral treatment TG 101348 has completed a clinical Phase I/II trial in patients with myelofibrosis, which disrupts the body's regular production of blood cells. Additional clinical studies are planned to start in the second half of 2010.