Grabar Law Office is investigating claims on behalf of shareholders of Altimmune, Inc. (NASDAQ: ALT). The investigation concerns whether certain officers and directors breached the fiduciary duties they owed to the company.

Altimmune is a clinical stage biopharmaceutical company focused on developing treatments for obesity, metabolic and liver diseases. The Company’s lead product candidate, pemvidutide (formerly known as ALT-801), is a novel, investigational, peptide-based GLP- 1/glucagon dual receptor agonist. Pemvidutide is currently in clinical development for obesity and metabolic associated steatohepatitis (“MASH”).

A recently filed federal securities class action complaint alleges that Altimmune Inc. (NASDAQ: ALT), via certain of its officers provided the public with overwhelmingly positive statements leading up to the announcement of topline results that failed to account for the fibrosis reduction observed in the placebo group. Defendants provided these overwhelmingly positive statements to investors while, at the same time, misrepresenting and/or concealing material adverse facts concerning the true state of the results observed in Altimmune’s IMPACT Phase 2b MASH trial. Altimmune’s executives repeatedly touted their positive expectations and even went as far as to title the press release announcing IMPACT Phase 2b MASH trial topline results “Announces Positive Topline Results from the IMPACT Phase 2b MASH trial of Pemvidutide in the Treatment of MASH,” completely disregarding that one of two primary endpoints was not found to be statistically significant.  In fact, Defendants spent minimal time discussing the aforementioned failure during the Special Call hosted by Altimmune pertaining to the topline results, rather stating that the Company hoped for better results in the Phase 3 trial.

On June 26, 2025, Altimmune published a press release announcing topline results from the IMPACT Phase 2b MASH trial of Pemvidutide in the Treatment of MASH. While Defendants had continuously provided inflated expectations ahead of these results, the analysis showed a pointed failure by the Company to achieve statistical significance in its analysis of the fibrosis reduction primary endpoint in its IMPACT Phase 2b MASH trial. In particular, while a positive trend in fibrosis improvement was observed, statistical significance was not met due to a higher-than-expected placebo response. When questioned about this concerning miss, Defendants answered indifferently, attributing this result to the Phase 2 nature of the trial and stated that Altimmune was hoping for better results following the Phase 3 trial.

WHAT YOU CAN DO NOW: If you purchased Altimmune, Inc. (NASDAQ: ALT) shares prior to August 10, 2023, and still hold shares today, you are encouraged to contact Joshua Grabar at jgrabar@grabarlaw.com, or call 267-507-6085.  You can seek corporate reforms, the return of funds back to the company, and a court approved incentive award at no cost to you whatsoever. Alternatively, if purchased or otherwise acquired Altimmune securities between August 10, 2023 and June 25, 2025, inclusive (the “Class Period”), you can participate in the class action.