Altimmune Publishes IMPACT Phase 2b 48-Week MASH Data in The Lancet Gastroenterology & Hepatology: Significant Reductions in Liver Fat, Inflammation and Fibrosis
Altimmune, Inc. (Nasdaq: ALT), a biopharmaceutical company based in Morristown, New Jersey, on November 12 announced the publication of 48-week results from the IMPACT Phase 2b trial of pemvidutide in metabolic dysfunction-associated steatohepatitis (MASH) in The Lancet Gastroenterology & Hepatology. At Week 48, pemvidutide produced significant reductions versus placebo across multiple non-invasive measures of liver fat, hepatic inflammation and fibrosis, together with significant weight loss.
IMPACT was a randomized, double-blind, placebo-controlled trial that enrolled 212 participants with biopsy-confirmed MASH and fibrosis stages F2 or F3, with and without diabetes. Participants were randomized 1:2:2 to weekly subcutaneous pemvidutide at 1.2 mg or 1.8 mg, or placebo, for 48 weeks. The previously reported 24-week results met the primary endpoint of MASH resolution without worsening of fibrosis; the newly published paper reports 48-week secondary endpoints, including MASH resolution and fibrosis improvement.
Mazen Noureddin, M.D., the IMPACT trial's principal investigator and a professor of medicine at Houston Methodist Hospital, said the published results show that improvements seen earlier in treatment increased across multiple measures of liver health, including inflammation and, importantly, fibrosis, which plays a key role in long-term outcomes in MASH. Liver benefits were accompanied by weight loss and maintenance of glycemic control, with generally favorable gastrointestinal tolerability and no significant change in heart rate, providing a strong foundation for the ongoing PERFORMA Phase 3 trial, he said.
On safety, pemvidutide showed a generally favorable tolerability profile over 48 weeks despite being administered without dose titration. Approximately 1% of patients receiving pemvidutide discontinued treatment due to adverse events. Most adverse events were mild to moderate; gastrointestinal events were mostly mild to moderate and occurred predominantly within the first 8 weeks, and no imbalances in cardiac adverse events were observed versus placebo. Weight loss with the 1.8 mg dose appeared to continue through the end of the 48-week treatment period.
Pemvidutide is an investigational peptide with balanced 1:1 glucagon and GLP-1 dual receptor agonist activity. The FDA has granted it Fast Track designations for MASH and alcohol use disorder, as well as Breakthrough Therapy Designation for MASH. The company announced topline 48-week IMPACT data in December 2025, and the global PERFORMA Phase 3 trial in MASH was initiated in July 2026. (Source: Altimmune)
Source: Altimmune
Published by GSM · USA (original Chinese edition)
Photo: 图：人体肝脏示意图。NIH BioArt（NIAID 供图），Wikimedia Commons，公共领域。 / Image: Illustration of the human liver. NIH BioArt, courtesy of NIAID, via Wikimedia Commons, public domain.
