Continuing to build on the successful launch of Rezdiffra (resmetirom), Madrigal Pharmaceuticals Inc. is adding six preclinical-stage siRNA therapies to its metabolic dysfunction-associated steatohepatitis (MASH) pipeline in a deal with Ribo Life Science Co. Ltd. and its subsidiary, Ribocure Pharmaceuticals AB, that could be worth $4.4 billion if all milestones are achieved.