When an emerging biotech loses its pharmaceutical partner for its lead compound, its generally bad news. But when Sankyo Co. in February walked away from its development deal with Kai Pharmaceuticals -- a casualty of a pipeline reevaluation following Sankyo's merger with Daiichi -- the South San Francisco biotech got to keep the $20 million up front payment from the deal and regained full ownership of its first-in-class drug to treat reperfusion injury, which is damage to the heart following treatment for a heart attack.