Cephalon, Inc. has signed a definitive merger agreement to acquire Gemin X Pharmaceuticals, Inc., a privately-held biopharmaceutical company, for $225 million cash. Gemin X stockholders could also receive as much as $300 million in cash payments based on certain regulatory and sales milestones. The agreement is subject to customary closing conditions including the necessary regulatory approvals. The merger is expected to close in 2Q11.

Gemin X is developing a pipeline of targeted cancer therapeutics based on reinitiating programmed forms of cell death, including apoptotic and autophagic cell death, as well as the inhibition of metabolism in cancer cells. Gemin X’s lead product candidate, obatoclax (GX15-070), is a pan Bcl-2 inhibitor currently in Phase II trials in patients with extensive stage small cell lung cancer (ES-SCLC). The trial is evaluating the safety and efficacy of obatoclax as a first line treatment in combination with standard chemotherapy.

“I am pleased to have entered into a merger agreement with Gemin X,” said Kevin Buchi, chief executive officer of Cephalon. “Its array of novel, targeted cancer therapeutics is a welcome addition to our current oncology portfolio. I am particularly excited about Gemin X’s lead compound, obatoclax, which if successful has the potential to significantly benefit patients suffering from small cell lung cancer — a devastating disease for which current treatments are limited and additional therapies are desperately needed.”