Five Prime Therapeutics Inc. said it's licensing a family of monoclonal antibodies (Mabs) to Seattle Genetics Inc. for inclusion in new early stage cancer-killing antibody-drug conjugate (ADC) candidates, all directed to a single target. The deal holds $5 million up front for Five Prime, plus up to $525 million in milestone payments for the first two candidates. South San Francisco-based Five Prime's shares (NASDAQ:FPRX) rose about 18% on the deal, which interim CEO William Ringo said allows the firm "to realize value from our preclinical pipeline while prioritizing our clinical investments based on upcoming data readouts."