Madrigal Pharmaceuticals continued its metabolic dysfunction–associated steatohepatitis (MASH) strategy with another genetic-medicine deal, licensing an Arrowhead siRNA asset aimed at a defined disease driver. The transaction is valued at up to $1 billion and is positioned as complementary to Madrigal’s own MASH franchise. The company described the asset as targeting PNPLA3, a genetic driver of MASH that is present in a substantial fraction of patients with moderate-to-advanced fibrosis. Madrigal said earlier Phase 1 data showed liver fat reductions in genetically defined patients after dosing. Madrigal framed the deal as a modality-agnostic approach to build a pipeline of therapies that can address patient subtypes while complementing the broad effects of Rezdiffra, the first FDA-approved oral treatment for adults with MASH and moderate to advanced fibrosis. The licensing adds a precision layer to a field where differentiation is increasingly tied to genotype-defined efficacy and combination potential, not just general metabolic endpoints.