Madrigal Pharmaceuticals extended its MASH deal strategy by securing a global licensing arrangement for an Arrowhead Pharmaceuticals asset that targets a genetic driver of metabolic dysfunction-associated steatohepatitis (MASH). The transaction is described as backloaded and comes after Johnson & Johnson had earlier handed back rights to a related siRNA development program. Madrigal already markets Rezdiffra (resmetirom) and has been building out an internal and partnered siRNA/combo pipeline in MASH. This new licensing continues the company’s focus on multi-mechanism approaches aimed at improving fibrosis and metabolic outcomes. For Arrowhead, the agreement provides an alternate route to advance a phase 1 candidate after the prior partner exited, while for Madrigal it strengthens the company’s “combo” narrative ahead of later-line competition. The market impact will depend on how the licensed asset performs in subsequent dose-finding, biomarker, and efficacy cohorts, and whether it can differentiate versus other late-stage MASH programs as regulators and payers demand demonstrable clinical endpoints.