"Best of EASL" oral presentation highlights meaningful reductions in triglycerides, cholesterol, and blood pressure, along with improvements in key metabolic risk factors

PERFORMA Phase 3 trial to further evaluate the broad metabolic and liver-related effects of pemvidutide

GAITHERSBURG, Md., May 28, 2026 (GLOBE NEWSWIRE) -- Altimmune, Inc. (NASDAQ:ALT), a late clinical-stage biopharmaceutical company developing pemvidutide to address serious liver diseases, today announced that new 48-week data from the IMPACT Phase 2b trial show that pemvidutide, an investigational balanced glucagon/GLP-1 dual receptor agonist, significantly reduced elevated lipids while improving multiple cardiometabolic risk factors in patients with metabolic dysfunction-associated steatohepatitis (MASH). The findings demonstrated reductions in triglycerides and total cholesterol, along with improvements in weight, waist circumference and blood pressure, highlighting the broad impact of pemvidutide on key drivers of MASH. The data were presented for the first time at the European Association for the Study of the Liver (EASL) Congress 2026 in Barcelona, Spain.

"MASH therapies that can address both liver disease and its underlying metabolic drivers are urgently needed to improve outcomes for patients," said Mazen Noureddin, M.D., IMPACT trial principal investigator, Professor of Medicine at Houston Methodist Hospital, and Chief Scientific Officer and Co-Chairman of Summit Clinical Research. "These 48-week IMPACT trial findings are particularly compelling because they demonstrate meaningful reductions in liver fat and fibrosis biomarkers, and in lipids elevated at baseline, alongside improvements in weight and other cardiometabolic risk factors. In patients with MASH, where cardiovascular disease remains a leading cause of mortality, seeing this type of broad metabolic impact is highly relevant to overall patient outcomes."

Highlights of the 48-week data presented at EASL 2026 include:

Pemvidutide 1.8 mg treatment resulted in significant reductions in serum lipid levels among patients with elevated baseline values versus placebo, including:

Triglycerides reductions of -23.7%
Total cholesterol reductions of -15.4%

In addition to lipids, pemvidutide 1.8 mg treatment resulted in significant improvements in other metabolic risk factors versus placebo:

Weight loss of 7.5%, continuing throughout treatment with no plateauing
Reductions in body mass index of -3.0 kg/m²
Reductions in waist circumference (a measure of visceral adiposity that is associated with increased cardiovascular risk) of -5.3 cm
Improvements in systolic blood pressure of -4.0 mmHg and diastolic blood pressure of -2.2 mmHg

Results also showed that the safety profile of pemvidutide was maintained at 48 weeks, and the tolerability profile was generally favorable without dose titration. Approximately 1% of total patients receiving pemvidutide discontinued treatment due to adverse events (AEs). The majority of AEs were mild to moderate, and no imbalances in cardiac AEs were observed with pemvidutide versus placebo. Most gastrointestinal AEs were mild to moderate in severity and predominantly occurred within the first 8 weeks.

Previously reported IMPACT Phase 2b trial results showed the proportion of patients achieving both a ≥0.5 reduction in Enhanced Liver Fibrosis (ELF) and a ≥30% reduction in Liver Stiffness Measurement (LSM) at week 48 was 3.2% with placebo, compared with 27.8% for pemvidutide 1.2 mg (p<0.001) and 32.4% for pemvidutide 1.8 mg (p<0.0001).

"These new 48-week results highlight the breadth of the impact of pemvidutide across some of the most critical cardiometabolic risk factors, including lipids, weight and blood pressure," said Christophe Arbet-Engels, M.D., Ph.D., Chief Medical Officer of Altimmune. "Across multiple analyses, we are seeing consistent data that reinforce our confidence in the unique mechanism of pemvidutide – a balanced 1:1 ratio of glucagon and GLP-1 – and its potential to address significant unmet needs in this patient population. Given the promising findings from the IMPACT Phase 2b trial, we are eager to initiate our PERFORMA Phase 3 trial later this year to further assess the efficacy and safety of pemvidutide in patients with MASH."

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 RECLAIM Phase 2 trial in AUD completed enrollment in November 2025 and topline data are expected in third quarter 2026. The RESTORE trial in ALD was initiated in July 2025, and enrollment completion is expected in the third quarter 2026. The Company plans to initiate the PERFORMA Phase 3 trial, a multinational, randomized, double-blind, placebo-controlled, parallel-group study of pemvidutide in patients with MASH in the second half of 2026.

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 investigational 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 the completed IMPACT and planned PERFORMA Phase 3 trials, the timing of key milestones for the Company's clinical programs, including the anticipated launch of the PERFORMA Phase 3 trial in MASH, 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 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

Pemvidutide Demonstrates Significant Metabolic Improvements in Patients with MASH in New 48‑Week IMPACT Phase 2b Data Presented at EASL 2026