Cephalon Inc (NASDAQ:CEPH) said late Monday that it will acquire privately held Gemin X Pharmaceuticals for $225 million in cash, in a deal to strengthen the company’s lineup of cancer treatments.Gemin X's private shareholders could receive up to an additional $300 million in cash payments if certain regulatory and sales goals are achieved.Kevin Buchi, CEO of Cephalon, said, "I am pleased to have entered into a merger agreement with Gemin X. 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."