Abstract presenting 48-week IMPACT Phase 2b efficacy and safety data selected for inclusion in “Best of EASL 2026” by EASL

Oral presentation will highlight further the 48-week IMPACT efficacy and safety data

Late-breaker abstract featuring new digital pathology analysis of liver fibrosis regression from IMPACT 24-week data

GAITHERSBURG, Md., May 13, 2026 (GLOBE NEWSWIRE) -- Altimmune, Inc. (Nasdaq: ALT), a late clinical-stage biopharmaceutical company developing pemvidutide to address serious liver diseases, today announced that analyses of data from its IMPACT Phase 2b clinical trial in metabolic dysfunction-associated steatohepatitis (MASH) will be presented at the European Association for the Study of the Liver (EASL) Congress 2026, taking place May 27-30 in Barcelona, Spain.

Data will be featured in both an oral presentation and several poster sessions, including a late-breaking poster presentation. The company also announced that its abstract on 48-week results has been selected by EASL as Best of EASL 2026 in their summary deck for its noteworthy contribution to the scientific program of the EASL congress.

The oral presentation will showcase 48-week efficacy and safety results from the IMPACT Phase 2 trial, while additional poster presentations will focus on new 24-week findings, including digital pathology analysis of fibrosis regression, a response analysis to multiple non-invasive tests (NITs) of liver inflammation and fibrosis and data on cardiovascular measures.

Oral Presentation

Abstract Title: Week 48 Top-Line Results from the Phase 2b, Multicenter, Randomized, Placebo-Controlled IMPACT Trial of Pemvidutide in Metabolic Dysfunction-Associated Steatohepatitis
Session: MASLD: Clinical and Therapeutic Aspects I (OS-016)
Date/Time: Thursday, May 28, 17:00 CEST
Presenter: Dr. Mazen Noureddin, Professor of Medicine, Houston Methodist Hospital; Chief Scientific Officer and Co-Chairman, Summit Clinical Research

Poster Presentations

Late-Breaking Poster
Abstract Title: Pemvidutide Treatment Led to Fibrosis Regression After 24 Weeks in Patients with MASH: Quantitative Digital Pathology Analysis from the Phase 2b IMPACT Trial
Session: Late Breaker Posters (LBP-036)
Date/Time: Wednesday, May 27, 08:30 CEST
Presenter: Dr. Shaheen Tomah, Director, Clinical Development, Altimmune

Poster Presentation
Abstract Title: Concurrent Responses in Multiple Non-Invasive Tests for Hepatic Inflammation and Fibrosis Following Pemvidutide Treatment: 24-Week Responder Analyses from the Phase 2b IMPACT Trial
Session: MASLD: Therapy (TOP-176)
Date/Time: Friday, May 29, 08:30-17:00 CEST
Presenter: Dr. Scot Roberts, Chief Scientific Officer, Altimmune

Poster Presentation
Abstract Title: Effect of Pemvidutide on Cardiovascular Risk Factors in Patients with MASH: 48-Week Results from the Phase 2b IMPACT Trial
Session: MASLD: Therapy (FRI-201)
Date/Time: Friday, May 29, 08:30-17:00 CEST
Presenter: Dr. Shaheen Tomah, Director, Clinical Development, Altimmune

A copy of the oral presentation and posters will be available in the Events section of the Altimmune website.

About the IMPACT Phase 2b Study
The randomized, placebo-controlled, double-blind IMPACT Phase 2b trial (NCT05989711) enrolled 212 participants with biopsy-confirmed metabolic dysfunction-associated steatohepatitis (MASH) and fibrosis stages F2 or F3, with and without diabetes. Study participants were randomized 1:2:2 to receive weekly subcutaneous pemvidutide doses at either 1.2 mg, 1.8 mg or placebo for 48 weeks. The primary efficacy endpoints, measured at 24 weeks, were MASH resolution without worsening of fibrosis, or fibrosis improvement without worsening of MASH. Secondary endpoints included non-invasive tests of fibrosis and weight loss measured at 24 and 48 weeks.

About Pemvidutide
Pemvidutide is a novel, investigational peptide with balanced 1:1 glucagon/GLP-1 dual receptor agonist activity, in development for the treatment of metabolic dysfunction-associated steatohepatitis (MASH), alcohol use disorder (AUD) and alcohol-associated liver disease (ALD). The activation of glucagon receptors results in direct effects on the liver, including reductions in liver fat, inflammation and fibrosis, while GLP-1 receptors mediate metabolic effects such as appetite suppression and weight loss.

The FDA granted Fast Track designations to pemvidutide for the treatment of MASH and AUD, as well as Breakthrough Therapy Designation for MASH. In December 2025, the Company announced 48-week data from the IMPACT Phase 2b trial in MASH. The Phase 2 RECLAIM trial in AUD and RESTORE trial in ALD were initiated in May 2025 and July 2025, respectively, and are currently ongoing.

About Altimmune 
Altimmune is a late clinical-stage biopharmaceutical company developing therapies for patients with serious liver diseases. The Company’s lead candidate, pemvidutide, is a unique dual-action therapy targeting both glucagon and GLP-1 receptors in a balanced 1:1 ratio in development for the treatment of metabolic dysfunction-associated steatohepatitis (MASH), alcohol use disorder (AUD) and alcohol-associated liver disease (ALD). For more information, please visit www.altimmune.com.

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Forward-Looking Statements

Any statements made in this press release related to the development or commercialization of pemvidutide, an investigational product candidate, and other business, regulatory and financial matters including without limitation, clinical trial study design, status, correspondence, results and data, including related to the completed IMPACT trial, or the ongoing RECLAIM and RESTORE trials, the timing of key milestones for the Company’s clinical programs, future plans or expectations for pemvidutide for the treatment of MASH, AUD and ALD, the potential benefits of Fast Track and Breakthrough Therapy Designations, including potential regulatory timeline and approval benefits, the Company’s financial position, and the prospects for receiving regulatory approval or commercializing or selling any product or drug candidates, financial results, are forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. In addition, when or if used in this press release, the words "may," "could," "should," "anticipate," "believe," "estimate," "expect," "intend," "plan," "predict" and similar expressions and their variants, as they relate to Altimmune, Inc. may identify forward-looking statements. The Company cautions that these forward-looking statements are subject to numerous assumptions, risks, and uncertainties, which change over time. Important factors that may cause actual results to differ materially from the results discussed in the forward-looking statements or historical experience include risks and uncertainties, including risks relating to: delays in regulatory review, manufacturing and supply chain interruptions, access to clinical sites, enrollment, adverse effects on healthcare systems and disruption of the global economy; the reliability of the results of studies relating to human safety and possible adverse effects resulting from the administration of the Company's product candidates; the Company's ability to manufacture clinical trial materials on the timelines anticipated; and the success of future product advancements, including the success of future clinical trials. Further information on the factors and risks that could affect the Company's business, financial conditions and results of operations are contained in the Company's filings with the U.S. Securities and Exchange Commission, including under the heading "Risk Factors" in the Company's most recent annual report on Form 10-K, quarterly report on Form 10-Q and the Company’s other filings with the SEC, which are available at www.sec.gov.

Investor Contact:
Luis Sanay, CFA
Vice President, Investor Relations
ir@altimmune.com

Media Contact:
Real Chemistry 
altimmune@realchemistry.com