Altimmune Stock Falls 20% After Pemvidutide 48-Week Trial Update

(RTTNews) - Altimmune, Inc. (ALT) shares fell 20.40%, closing at $4.02, down $1.03, after the company announced 48-week results from its Phase 2b IMPACT trial evaluating pemvidutide in patients with MASH.

The decline came despite the company reporting that pemvidutide met key measures of success at 48 weeks, including statistically significant improvements in non-invasive markers of liver fibrosis, reductions in liver fat, and sustained weight loss versus placebo. Altimmune also said the data support alignment with the FDA to advance pemvidutide into Phase 3 development.

On the day of the announcement, ALT opened near $4.85, reached an intraday high of $4.90, and fell to a low of $3.95, compared with a previous close of $5.05. The stock trades on the Nasdaq.

Altimmune's 52-week range is approximately $2.90 - $11.16. While the clinical results met stated endpoints, the sharp selloff suggests investors may be reassessing expectations around the commercial outlook, competitive landscape, and timelines for Phase 3 execution.