Amira Pharmaceuticals, a privately held company in San Diego, has agreed to be acquired by New York-based Bristol-Myers Squibb (NYSE: BMY) for $325 million in cash upfront, plus additional milestone payments of $150 million, meaning the deal could be worth up to $475 million for Amira shareholders. Bristol said in a statement that it plans to retain Amira’s scientists, and keep them in San Diego. Amira had 25 employees at last count, in November.