Altimmune Stock Plunges 54% Despite Positive MASH Trial Results

(RTTNews) - Altimmune, Inc. (ALT) shares plummeted 54.02 percent to $3.54 on Thursday despite announcing positive topline results from its Phase 2b IMPACT trial evaluating pemvidutide for treating metabolic dysfunction-associated steatohepatitis.

The stock opened sharply lower at $2.96 and ranged between $2.91 and $3.83 on heavy volume of 75.5 million shares, far exceeding the average of 2.9 million on the Nasdaq. The steep decline erased much of the stock's recent gains, bringing it close to its 52-week low of $2.91, with a 52-week high of $11.16.

While the drug met key endpoints, achieving MASH resolution without fibrosis worsening and showing strong anti-fibrotic signals in supplemental analyses, the lack of statistically significant improvement in fibrosis in the primary analysis appears to have spooked investors.