Kiadis Pharma NV’s takeover last year of Cytosen Therapeutics Inc. to get a natural killer (NK) platform paid off in a potentially huge way, with Sanofi SA paying €17.5 million (US$19.7 million) up front in a licensing deal with as much as €857.5 million more if preclinical, clinical, regulatory and commercial goals are reached, as well as up to double-digit royalties.