Altimmune (NASDAQ:ALT) shares jumped 14% on Monday after the company said its liver disease candidate pemvidutide had been granted Breakthrough Therapy Designation by the U.S. Food and Drug Administration for the treatment of metabolic dysfunction-associated steatohepatitis (MASH).
The designation, designed to speed the development and regulatory review of therapies that may offer meaningful advantages over existing options, was based on 24-week data from Altimmune’s IMPACT Phase 2b trial. Results showed statistically significant resolution of MASH without worsening fibrosis, alongside reductions in liver fat and improvements across a range of non-invasive diagnostic measures.
Altimmune, which is in the late clinical stage of development, also reported that topline data at 48 weeks from the same trial demonstrated continued gains in key non-invasive markers, supporting the drug’s ongoing antifibrotic effect. Patients treated with the 1.8 mg dose achieved additional weight loss with no sign of a plateau, while the therapy maintained a favorable tolerability profile.
“The FDA’s Breakthrough Therapy Designation for pemvidutide in MASH reinforces the promise of its clinical profile and potential to address significant unmet needs in this serious, progressive liver disease,” said Jerry Durso, President and Chief Executive Officer of Altimmune.
The company recently concluded an end-of-Phase-2 meeting with the FDA, reaching agreement on the framework for a registrational Phase 3 study in MASH patients with moderate to advanced fibrosis. Altimmune plans to launch the trial with multiple pemvidutide dose arms over a 52-week treatment period, incorporating biopsy-based endpoints intended to support a potential accelerated approval pathway.