K. Peter Hirth, CEO of Plexxikon

Plexxikon, a drug discovery and development company based in West Berkeley, announced yesterday that it has agreed to be acquired by Daiichi-Sankyo, a Japan-based global pharmaceutical company. Daiichi-Sankyo is paying $805 million upfront for Plexxikon, and near-term milestone payments connected to approval of its PLX4032 oral drug to treat melanomas could add another $130 million to the purchase price.

According to a Plexxikon spokesperson, the company will remain in Berkeley at its current location next to Aquatic Park. Plexxikon currently has 43 employees in Berkeley and no layoffs are planned.

Plexxikon focuses on the discovery and development of novel, small molecule pharmaceuticals. It has a proprietary discovery platform, and is active in a number of different therapeutic areas, including cardio-renal disease, central nervous system, inflammation, metabolic disease and oncology

The promising PLX4032 targets the oncogenic BRAF mutation present in about half of melanoma cancers and 8% of all solid tumors. Interim data from a Phase 3 controlled study is promising, according to the company. Plexxikon and co-development partner Roche plan to file for market approval in the U.S. and Europe this year. Earlier this year, Plexxikon announced that it had an agreement to co-promote PLX4032 with Roche’s U.S. commercial oncology unit, Genentech. Following the acquisition, Daiichi-Sankyo will retain the U.S. co-promotion rights for PLX4032.

Closure of the transaction is subject to clearance under the Hart-Scott-Rodino Antitrust Improvements Act and other customary closing conditions.

Lance Knobel (Berkeleyside co-founder) has been a journalist for nearly 40 years. Much of his career was in business journalism. He was editor-in-chief of both Management Today, the leading business magazine...