Altimmune Announces Publication of IMPACT Phase 2b Trial Data in The Lancet and Concurrent Late-Breaking Oral Presentation at AASLD The Liver Meeting® 2025
Altimmune (NASDAQ: ALT) announced publication in The Lancet of 24-week IMPACT Phase 2b results for pemvidutide in MASH and a late-breaking oral presentation at AASLD The Liver Meeting® 2025 on Nov 11, 2025.
Key 24-week findings: MASH resolution occurred in 58% (1.2 mg) and 52% (1.8 mg) versus 20% for placebo; liver fat normalization reached 31% and 44% versus 4% for placebo; mean weight reductions were −4.8% and −5.8% versus −0.5% for placebo. Multiple non-invasive tests (MRI-PDFF, FibroScan, cT1, ELF, PRO-C3, FAST) showed consistent improvements and liver stiffness fell by −3.7 kPa and −2.2 kPa for active doses. Safety/tolerability were described as favorable with low discontinuation rates. Altimmune said longer-term NIT and weight-loss readouts will be provided in Q4 2025.
Altimmune (NASDAQ: ALT) ha annunciato la pubblicazione su The Lancet dei risultati a 24 settimane dello studio IMPACT Phase 2b su pemvidutide in MASH e una presentazione orale a margine a AASLD The Liver Meeting® 2025 dell'11 novembre 2025.
Principali risultati a 24 settimane: risoluzione MASH si è verificata nel 58% (1,2 mg) e 52% (1,8 mg) rispetto al 20% per placebo; normalizzazione del grasso epatico raggiunta nel 31% e 44% rispetto al 4% per placebo; riduzioni di peso medie pari a −4,8% e −5,8% rispetto a −0,5% per placebo. Diversi test non invasivi (MRI-PDFF, FibroScan, cT1, ELF, PRO-C3, FAST) hanno mostrato miglioramenti coerenti e la rigidità epatica è scesa di −3,7 kPa e −2,2 kPa per le dosi attive. La sicurezza/tollerabilità è stata descritta come favorevole con bassi tassi di interruzione. Altimmune ha indicato che i risultati a più lungo termine di NIT e perdita di peso saranno forniti nel Q4 2025.
Altimmune (NASDAQ: ALT) anunció la publicación en The Lancet de los resultados de 24 semanas del ensayo IMPACT fase 2b sobre pemvidutide en MASH y una presentación oral de última hora en AASLD The Liver Meeting® 2025 el 11 de noviembre de 2025.
Hallazgos clave de 24 semanas: resolución de MASH se dio en el 58% (1,2 mg) y 52% (1,8 mg) frente al 20% con placebo; normalización de la grasa hepática alcanzó el 31% y 44% frente al 4% de placebo; reducciones de peso medias de −4,8% y −5,8% frente a −0,5% para placebo. Varios tests no invasivos (MRI-PDFF, FibroScan, cT1, ELF, PRO-C3, FAST) mostraron mejoras consistentes y la rigidez hepática cayó en −3,7 kPa y −2,2 kPa para las dosis activas. La seguridad/tolerabilidad se describió como favorable con bajas tasas de discontinuación. Altimmune indicó que los resultados de NIT y pérdida de peso a más largo plazo se comunicarán en el cuarto trimestre de 2025.
Altimmune(NASDAQ: ALT)는 MASH에서 pemvidutide의 IMPACT 2b 단계 24주 결과를 The Lancet에 발표했고, 2025년 AASLD The Liver Meeting®에서 11월 11일자로 최신 속보 구두 발표를 진행했다.
24주 주요 발견: MASH 해소는 58%(1.2 mg), 52%(1.8 mg)에서 발생했고, 위약은 20%였다; 간 지방 정상화는 각각 31%와 44%로 위약의 4%에 비해 높았다; 평균 체중 감소는 −4.8%와 −5.8%로 위약의 −0.5%에 비해 컸다. 비침습 검사들(MRI-PDFF, FibroScan, cT1, ELF, PRO-C3, FAST)은 일관된 개선을 보였고 간경도는 활성 용량에서 각각 −3.7 kPa, −2.2 kPa 감소했다. 안전성/내약성은 불리하지 않으며 중단율이 낮다고 설명되었다. Altimmune은 더 긴 기간의 NIT 및 체중 감소 지표가 2025년 4분기에 제공될 것이라고 밝혔다.
Altimmune (NASDAQ : ALT) a annoncé la publication dans The Lancet des résultats à 24 semaines de l’étude IMPACT Phase 2b sur le pemvidutide dans le cadre de MASH et une présentation orale d’actualité lors du AASLD The Liver Meeting® 2025 le 11 novembre 2025.
Principaux résultats à 24 semaines : résolution du MASH survenue chez 58% (1,2 mg) et 52% (1,8 mg) contre 20% pour le placebo ; normalisation de la graisse hépatique atteinte à 31% et 44% contre 4% pour le placebo ; réductions de poids moyennes de −4,8% et −5,8% contre −0,5% pour le placebo. Plusieurs tests non invasifs (MRI-PDFF, FibroScan, cT1, ELF, PRO-C3, FAST) ont montré des améliorations cohérentes et la rigidité du foie a diminué de −3,7 kPa et −2,2 kPa pour les doses actives. La sécurité/tolérabilité a été décrite comme favorable avec des taux d’interruption faibles. Altimmune a indiqué que les résultats à plus long terme de NIT et de perte de poids seront fournis au cours du T4 2025.
Altimmune (NASDAQ: ALT) kündigte die Veröffentlichung der 24-Wochen-Ergebnisse von IMPACT Phase 2b zu Pemvidutid in MASH in The Lancet an und präsentierte am 11. November 2025 eine späte mündliche Präsentation auf der AASLD The Liver Meeting® 2025.
Wichtige 24-Wochen-Ergebnisse: MASH-Auflösung trat bei 58% (1,2 mg) bzw. 52% (1,8 mg) auf, gegenüber 20% Placebo; Leberfett-Normalisierung erreichte 31% bzw. 44% gegenüber 4% Placebo; mittlere Gewichtsreduktionen von −4,8% bzw. −5,8% gegenüber −0,5% bei Placebo. Mehrere nichtinvasive Tests (MRI-PDFF, FibroScan, cT1, ELF, PRO-C3, FAST) zeigten konsistente Verbesserungen und die Lebersteifigkeit sank um −3,7 kPa bzw. −2,2 kPa bei den aktiven Dosen. Sicherheit/Tolerabilität wurde als günstig beschrieben mit niedrigen Abbruchraten. Altimmune sagte, dass längerfristige NIT- und Gewichtsverlust-Ergebnisse im Q4 2025 vorgelegt werden.
Altimmune (NASDAQ: ALT) أعلنت عن نشر في The Lancet لنتائج 24 أسبوعًا من تجربة IMPACT Phase 2b عن pemvidutide في MASH وعرض شفوي عاجل في AASLD The Liver Meeting® 2025 في 11 نوفمبر 2025.
النتائج الأساسية عند 24 أسبوعًا: إيجاد حل لـ MASH حدث عند 58% (1.2 mg) و52% (1.8 mg) مقابل 20% بالدواء الوهمي؛ تصحيح دهون الكبد وصل إلى 31% و44% مقابل 4% بالدواء الوهمي؛ خفض الوزن المتوسط كان −4.8% و−5.8% مقابل −0.5% بالدواء الوهمي. اختبارات غير جراحية متعددة (MRI-PDFF، FibroScan، cT1، ELF، PRO-C3، FAST) أظهرت تحسنًا متسقًا وانخفضت صلابة الكبد بـ −3.7 كاپا و−2.2 كاپا للجرعات النشطة. وُصف السلامة/التحمل بأنها ميسرة مع معدلات تخلي منخفضة. ذكرت Altimmune أن نتائج NIT وفقدان الوزن على المدى الأطول ستُقدم في الربع الرابع من 2025.
- MASH resolution 58% (1.2 mg) and 52% (1.8 mg) vs 20% placebo
- Liver fat normalization 31% (1.2 mg) and 44% (1.8 mg) vs 4% placebo
- Weight reduction −4.8% (1.2 mg) and −5.8% (1.8 mg) vs −0.5% placebo
- Liver stiffness reduced by −3.7 kPa (1.2 mg) and −2.2 kPa (1.8 mg)
- Fibrosis histologic improvement modest: 33% (1.2 mg) and 36% (1.8 mg) vs 28% placebo
- Data limited to 24 weeks; longer-term histology and outcomes pending Q4 2025 readout
Insights
Phase 2b 24-week data show statistically significant MASH resolution, antifibrotic signals, and meaningful weight loss with favorable tolerability.
pemvidutide produced MASH resolution in
The therapeutic mechanism cited is balanced 1:1 glucagon/GLP-1 receptor agonism aimed at hepatic and metabolic drivers. Safety signals appear acceptable at 24 weeks: low discontinuation rates (0–2%), few serious adverse events, and no investigator-attributed serious adverse events. Key dependencies include the durability of histologic benefit beyond 24 weeks and whether longer-term non-invasive test (NIT) changes translate into clinically meaningful fibrosis regression; those longer-term NITs and weight-loss readouts are scheduled for a final report in
24-week data demonstrated significant MASH resolution and weight loss, and strong evidence of anti-fibrotic activity with a favorable tolerability profile
Significant improvements observed in secondary endpoints, including reductions in liver fat, inflammation and biomarkers of fibrosis
GAITHERSBURG, Md., Nov. 11, 2025 (GLOBE NEWSWIRE) -- Altimmune, Inc. (Nasdaq: ALT), a late clinical-stage biopharmaceutical company developing novel peptide-based therapeutics for liver and cardiometabolic diseases, today announced publication in The Lancet of 24-week efficacy and safety data from the ongoing IMPACT Phase 2b trial of pemvidutide in patients with metabolic dysfunction-associated steatohepatitis (MASH) in a paper titled “Safety and efficacy of weekly pemvidutide versus placebo for metabolic dysfunction-associated steatohepatitis (IMPACT): 24-week results from a multicentre, randomised, double-blind, phase 2b study”.
Dr. Mazen Noureddin, M.D., IMPACT trial principal investigator, Professor of Medicine at Houston Methodist Hospital and Co-Chairman of the Board for Summit and Pinnacle Clinical Research will present these data in a late-breaking oral presentation at The Liver Meeting® 2025, hosted by the American Association for the Study of Liver Diseases (AASLD) in Washington, D.C.
Topline 24-week data from the IMPACT Phase 2b trial were previously announced in June 2025, demonstrating that pemvidutide, Altimmune’s 1:1 glucagon/GLP-1 agonist, achieved statistically significant MASH resolution without worsening of fibrosis, meaningful reductions in fibrosis, liver fat, and clinically relevant weight loss with favorable tolerability.
The Lancet publication describes changes across key non-invasive tests (NITs) from blood-based biomarkers (ELF, PRO-C3, and AST), imaging modalities (MRI-PDFF, FibroScan®, and cT1), and combined measures such as FAST score – all markers that offer consistent evidence of fibrosis reduction and improvement in liver inflammation.
“As the primary goal of treatment for patients with MASH is to reverse liver fibrosis to prevent progression to cirrhosis and other serious and life-threatening complications, the totality of the 24-week clinical data from the IMPACT trial is very encouraging,” said Dr. Mazen Noureddin. “Given the significant resolution of MASH that occurred after only 24 weeks of treatment, along with strong evidence of anti-fibrotic activity and weight loss, the profile of pemvidutide suggests it has the potential to meaningfully alter the course of this disease.”
Highlights from the Published IMPACT 24-Week Results
| Endpoint | Placebo (N=86) | 1.2 mg (N=41) | 1.8 mg (N=85) |
| Primary Endpoint: Histology (ITT Analysis) | |||
| MASH resolution without worsening of fibrosis, LSM % patients (SE) | 20 (4.3) | 58 (7.9) **** | 52 (5.6) **** |
| Fibrosis improvement without worsening of MASH, LSM % patients (SE) | 28 (4.9) | 33 (7.5) | 36 (5.3) |
| Secondary Endpoints | |||
| Change in liver stiffness measurement, kPa (SE) | -0.7 (0.5) | -3.7 (0.7) *** | -2.2 (0.5) * |
| Change in Enhanced Liver Fibrosis score (SE) | 0.03 (0.1) | -0.6 (0.1) *** | -0.5 (0.1) *** |
| Change in corrected T1 relaxation time, ms (SE) | -14.7 (11.9) | -124.6 (16.1) *** | -134.7 (11.9) *** |
| Normalization of liver fat content (≤ | 3/76 ( | 12/39 ( **** | 35/79 ( |
| Body weight relative reduction, % (SE) | −0.5 (0.3) | −4.8 (0.5) *** | −5.8 (0.3) *** |
| Adverse Events (AEs) | |||
| Adverse event leading to the discontinuation of treatment, n (%) | 2 ( | 0 ( | 1 ( |
| Any serious adverse event, n (%) | 3 ( | 1 ( | 3 ( |
| Serious adverse event considered by the investigator to be related to assigned treatment, n (%) | 0 ( | 0 ( | 0 ( |
Data are presented as least squares mean (SE) unless indicated otherwise. A treatment policy estimand was applied with missing outcomes due either to missing biopsies or treatment discontinuations treated as non-responders (composite estimand). Comparisons versus placebo for the primary endpoints were made using the Chi-square test; **** p <0.0001 vs. placebo. The Cochran-Mantel-Haenszel test was applied to endpoints that were categorical in nature; **** p <0.0001 vs. placebo. Comparisons versus placebo were made using mixed models for repeated measures for endpoints measured at multiple time points and analysis of covariance for endpoints measured at baseline and week 24; * p <0.05, *** p <0.001 vs. placebo.
“The dual glucagon and GLP-1 receptor agonism of pemvidutide, which has a unique, balanced 1:1 activity ratio, was intentionally designed to target both the hepatic and metabolic drivers of MASH. The strength of these IMPACT 24-week results, particularly the rapid resolution of MASH in 24 weeks, provides strong evidence for a reduction in fibrosis and significant reductions in other NITs, reinforcing our belief in the differentiated mechanism of pemvidutide and its potential to become an important treatment for patients with MASH,” said Christophe Arbet-Engels, M.D., Ph.D., Chief Medical Officer of Altimmune. “We also look forward to providing a final readout of longer-term NITs and weight loss from the IMPACT trial in the fourth quarter of 2025.”
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. Participants will receive a total of 48 weeks of treatment, and a final readout of longer-term NITs and weight loss is anticipated in the fourth quarter of 2025.
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 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, both areas of significant unmet medical need. The 48-week readout from the ongoing IMPACT Phase 2b MASH trial is expected in the fourth quarter of 2025. Phase 2 trials in AUD (RECLAIM) and ALD (RESTORE) were initiated in May 2025 and July 2025, respectively, and are currently ongoing.
About Altimmune
Altimmune is a late clinical-stage biopharmaceutical company developing novel peptide-based therapeutics for liver and cardiometabolic diseases. The Company’s lead product candidate is pemvidutide, a glucagon/GLP-1 dual receptor agonist 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.
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, the timing of key milestones for the Company’s clinical assets, future plans or expectations for pemvidutide for the treatment of MASH, AUD, and ALD, 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.
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FAQ
What did Altimmune (ALT) report in The Lancet about pemvidutide 24-week IMPACT results on Nov 11, 2025?
How much weight loss did pemvidutide produce in the IMPACT Phase 2b trial (ALT)?
What were the liver fat normalization rates for ALT’s pemvidutide at 24 weeks?
Did pemvidutide show evidence of antifibrotic activity in the IMPACT trial (ALT)?
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