X-Chem, Inc. has entered a drug discovery collaboration with Alexion, under which X-Chem will deploy its drug discovery platform to identify novel drug candidates against targets chosen by Alexion. The platform is based on an expansive, high-diversity library of more than 100 billion molecules.   Alexion will have exclusive worldwide rights to develop and commercialize novel compounds arising from the collaboration. X-Chem will receive an upfront payment and additional payments upon specified re...