Madrigal Pharmaceuticals said the U.S. Patent and Trademark Office has issued a Notice of Allowance for a new patent covering its once-daily liver drug Rezdiffra (resmetirom), the first and only Food and Drug Administration–approved treatment for noncirrhotic metabolic dysfunction-associated steatohepatitis (MASH) with moderate to advanced fibrosis. The patent, which focuses on the commercial weight-threshold dosing regimen specified on Rezdiffra’s FDA label, is expected to grant protection until 30 September 2044 and will be added to the FDA’s Approved Drug Products list, known as the Orange Book. Chief Executive Officer Bill Sibold called the allowance “a pivotal milestone” that reinforces the company’s long-term strategy for the therapy. Rezdiffra was cleared by the FDA earlier this year and is also being studied in an outcomes-focused Phase 3 trial in patients with compensated MASH cirrhosis. The additional intellectual-property shield is intended to help Madrigal maintain exclusivity as it scales commercial distribution and pursues broader indications.