TOKYO—Japanese pharma Eisai announced the signing of a definitive agreement to acquire Exton, Penn.-based Morphotek for approximately $325 million. The move is part of Eisai's plan to expand its R&D and clinical capabilities in the United States and will give the company added leverage in the growing therapeutic monoclonal antibodies market.

"Eisai's substantial intellectual and managerial resources will enable us to accelerate the development of our current therapeutic antibody pipeline as well as develop a number of additional clinical compounds to targets accessed from our broad network of research collaborations and to those discovered by Eisai researchers globally," said Morphotek CEO Nicholas Nicolaides. 

Using a human antibody platform, Morphotek has developed a pipeline of therapeutics in disease areas like cancer, rheumatoid arthritis, and infectious disease, with two treatments in early-stage clinical trials. According to Eisai officials, Morphotek can expect to maintain operational autonomy, but it is hoped that the company will work closely with Eisai's other U.S.-based properties. The companies expect the deal to close by Eisai's first quarter 2007.