Peptide education
Pemvidutide
ALT-801
Pemvidutide, also called ALT-801, is an investigational peptide that activates GLP-1 and glucagon receptors. Researchers have studied it in metabolic liver disease, weight management, and alcohol use disorder. No matching product was found in the FDA drug database or the EMA's EEA authorized-product dataset.
A phase 2 MASH trial found more biopsy-defined MASH resolution without worsening fibrosis than placebo at 24 weeks. Its separate fibrosis improvement endpoint was not met. A phase 3 trial is recruiting, with results still pending.
Overview
Quick answer
MASH is an inflammatory form of metabolic fatty liver disease. A change in liver fat on an MRI is not the same measurement as a change in liver tissue on a biopsy, and neither alone proves that liver failure or other long-term complications have been prevented.
What does it target?
Pemvidutide is designed to activate GLP-1 and glucagon receptors. Its two-target design is a research rationale, not proof that either receptor alone caused a particular clinical result.
What did the MASH study find?
In IMPACT, participants had biopsy-confirmed MASH and stage F2 or F3 fibrosis. At 24 weeks, MASH resolution without worsening fibrosis was more common with pemvidutide than placebo. Improvement in fibrosis without worsening MASH was not statistically different from placebo.
Is it approved?
No matching approved product was found in the FDA drug database or the EMA's EEA authorized-product dataset. Altimmune describes pemvidutide as investigational. FDA development designations do not authorize marketing.
What were the side effects?
Gastrointestinal effects, including nausea, vomiting, diarrhea, and constipation, were reported in studies. Rates differ with dose, population, and trial; longer-term and uncommon risks remain uncertain.
Evidence
Evidence snapshot
IMPACT reported MASH resolution without worsening fibrosis at 24 weeks; the separate fibrosis improvement endpoint did not meet statistical significance versus placebo.
An MRI-based study included 64 participants who continued from a prior 12-week trial. It did not measure biopsy-confirmed MASH resolution.
MOMENTUM studied weight in adults without diabetes. RECLAIM studied alcohol use disorder in people with overweight or obesity. Their topline findings are not interchangeable.
Searches of FDA drug data and the EMA's EEA authorized-product data found no matching product. The developer describes the drug as investigational.
Claims
Common claims vs evidence
| Claim | Human evidence | Verdict |
|---|---|---|
| Pemvidutide reverses liver scarring. | IMPACT's 24-week endpoint for fibrosis improvement without worsening MASH was not significantly different from placebo. The MASH resolution endpoint was met. | The reported biopsy findings do not establish reversal of fibrosis. Follow the separate endpoints and longer studies. |
| Reducing liver fat proves MASH has resolved. | The MASLD extension measured liver fat with MRI. IMPACT separately assessed tissue from liver biopsies in a different population. | No. Imaging and histology answer related but different questions. |
| Pemvidutide is an established treatment for alcohol use disorder. | The RECLAIM sponsor reported fewer heavy drinking days in a phase 2 trial of people with alcohol use disorder and overweight or obesity. | This early, sponsor-reported result does not establish an approved indication or replace established care. |
| A non-trial product has the same evidence as the study drug. | The trials tested material supplied within controlled clinical studies, not an independently verified product from a separate seller. | Trial results cannot establish another product's identity, strength, sterility, or clinical safety. |
Bottom line
Main takeaway
Pemvidutide is a drug candidate. No matching product was found in the FDA or EEA authorized-product datasets searched. Different studies looked at liver tissue, liver fat, body weight, and drinking behavior.
Check the population and endpoint first. A favorable MASH resolution result does not mean the separate fibrosis endpoint was met, and a weight-loss figure from another study does not answer that question.
Start with the IMPACT biopsy paper and the MASLD imaging extension. Treat the MOMENTUM and RECLAIM figures as sponsor toplines, and the PERFORMA registration as a study plan rather than a result.
Identity
What it is
Pemvidutide is a single investigational peptide designed to activate both GLP-1 and glucagon receptors. Altimmune is developing it for metabolic liver disease and is also studying alcohol-related conditions.
In metabolic dysfunction-associated steatotic liver disease, or MASLD, fat accumulates in the liver alongside metabolic risk factors. MASH is a form with liver inflammation and cell injury, and fibrosis refers to scarring. A person can have MASLD without having biopsy-confirmed MASH.
The obesity and alcohol use disorder studies answer different questions in different groups. Positive findings in one group do not establish a treatment effect for everyone with either condition.
Use context
Routes, doses, and cycle patterns
The following regimens describe the dose groups and follow-up periods used in controlled studies. Each trial had its own eligibility criteria, comparison group, and clinical monitoring.
Human studies and product labels
IMPACT biopsy study
- Purpose
- MASH resolution and fibrosis endpoints
- Context
- Phase 2b, adults with biopsy-confirmed MASH and F2 or F3 fibrosis
- Route
- Subcutaneous
- Amount
- 1.2 mg or 1.8 mg in active study arms
- Frequency
- Once weekly
- Duration
- 48-week trial, with the primary biopsy assessment at 24 weeks
The report describes these two study arms without dose titration. MASH resolution was more frequent than placebo; the separate fibrosis improvement endpoint did not meet statistical significance.
MASLD imaging extension
- Purpose
- MRI-measured liver-fat change
- Context
- Extension of a randomized MASLD study in adults with overweight or obesity
- Route
- Subcutaneous
- Amount
- 1.2 mg, 1.8 mg, or 2.4 mg in active study arms
- Frequency
- Once weekly
- Duration
- 24 weeks total across the parent study and extension
Only participants who completed the first portion could join the extension. In the parent study, the 1.2 mg and 1.8 mg groups had no titration, while the 2.4 mg group used a four-week titration: 0.6 mg in week one, 1.2 mg in week two, and 1.8 mg in weeks three and four before reaching 2.4 mg. Participants continued their assigned dose in the extension. Advanced fibro-inflammatory disease was excluded.
MOMENTUM weight study
- Purpose
- Weight change in adults without diabetes
- Context
- Phase 2 randomized trial, sponsor topline report
- Route
- Subcutaneous
- Amount
- 1.2 mg, 1.8 mg, or 2.4 mg in active study arms
- Frequency
- Once weekly
- Duration
- 48 weeks
The sponsor reported no titration for the 1.2 mg and 1.8 mg groups and a four-week titration to 2.4 mg. The report includes dose-specific weight changes and adverse events.
RECLAIM alcohol use disorder study
- Purpose
- Change in heavy drinking days
- Context
- Phase 2, adults with alcohol use disorder and overweight or obesity
- Route
- Subcutaneous
- Amount
- 2.4 mg target in the active study arm
- Frequency
- Once weekly
- Duration
- 24 weeks
Altimmune reported a two-step titration to 2.4 mg and topline results from the placebo-controlled trial.
What varies
- A biopsy result, an MRI result, and a change in drinking behavior are distinct endpoints.
- A phase 3 registration describes a planned study, not an established outcome.
- Trial drug identity and monitoring cannot be assumed for material obtained outside a trial.
Research
Research evidence
The most direct MASH evidence is the phase 2b IMPACT biopsy study. A smaller MASLD study measured liver fat by MRI, while the obesity and alcohol use disorder findings summarized here come from sponsor toplines. Altimmune also reported 48-week IMPACT non-invasive and safety results. PERFORMA is a registered phase 3 MASH study, with results still to come.
| Study / evidence area | Population | Design | Product context | Main outcome | Limitations | Weight |
|---|---|---|---|---|---|---|
| IMPACT | 212 adults with biopsy-confirmed MASH and F2 or F3 fibrosis, with or without diabetes | Randomized, double-blind, placebo-controlled phase 2b trial | Controlled investigational study drug | At 24 weeks, MASH resolution without worsening fibrosis occurred in 58% with 1.2 mg and 52% with 1.8 mg, versus 20% with placebo. The separate fibrosis improvement endpoint was not significantly different from placebo. | The reported primary biopsy assessment was at 24 weeks. It does not prove long-term prevention of liver complications. | Peer-reviewed phase 2 biopsy evidence |
| IMPACT, 48-week follow-up | The same 212 adults randomized in IMPACT with biopsy-confirmed MASH and F2 or F3 fibrosis | Randomized, placebo-controlled phase 2b trial | Sponsor-reported topline | Altimmune reported reductions in non-invasive fibrosis markers and mean weight changes of -4.5% and -7.5% with 1.2 mg and 1.8 mg, versus -0.2% with placebo at week 48. | The 48-week report was not a biopsy readout. Non-invasive measures do not establish histologic fibrosis improvement or long-term clinical outcomes. | Sponsor-reported phase 2 follow-up |
| MASLD extension | 64 participants continuing a trial in MASLD and overweight or obesity | Double-blind extension of a randomized placebo-controlled study | Controlled investigational study drug | At 24 weeks, relative MRI liver-fat reductions were 56.3%, 75.2%, and 76.4% across the 1.2 mg, 1.8 mg, and 2.4 mg arms, versus 14.0% with placebo. | A small extension selected from initial completers, without a biopsy endpoint and excluding advanced fibro-inflammatory disease. | Peer-reviewed imaging evidence |
| MOMENTUM | 391 adults with obesity or overweight and a related condition, without diabetes | Randomized, placebo-controlled phase 2 trial | Sponsor-reported topline | The sponsor reported mean weight change of -15.6% with 2.4 mg and -2.2% with placebo at 48 weeks. | The sponsor report is not a complete peer-reviewed trial publication; missing data and discontinuation affect interpretation. | Sponsor-reported phase 2 result |
| RECLAIM | People with moderate to severe alcohol use disorder and overweight or obesity | Randomized, placebo-controlled phase 2 trial | Sponsor-reported topline | At week 24 the sponsor reported a reduction of 4.20 heavy drinking days per week with 2.4 mg versus 2.75 with placebo, expressed as adjusted means. | Early sponsor-reported findings need full publication and replication; they do not establish treatment for all people with alcohol use disorder. | Sponsor-reported phase 2 result |
| PERFORMA | Adults with noncirrhotic MASH and F2 or F3 fibrosis | Registered phase 3 randomized, placebo-controlled study | ClinicalTrials.gov trial registration | The registry describes a recruiting study, not completed results. | Efficacy, long-term outcomes, and approval remain unresolved. | Ongoing research |
| RESTORE | Adults with alcohol-associated liver disease | Registered phase 2 randomized, placebo-controlled study | ClinicalTrials.gov trial registration | The study is active and no longer recruiting; efficacy results are pending. | Alcohol-associated liver disease and alcohol use disorder are separate study questions. | Ongoing research |
Cautions
Safety and unknowns
- In IMPACT, any adverse event was reported in 78% and 81% of participants in the 1.2 mg and 1.8 mg groups, versus 67% with placebo at 24 weeks. Most events were mild or moderate; these are all reported events, not necessarily events caused by the drug.
- At 48 weeks in IMPACT, the sponsor reported adverse events leading to treatment discontinuation in 0% and 1.2% of the 1.2 mg and 1.8 mg groups, versus 3.5% with placebo. This is a sponsor-reported topline result.
- In the sponsor's MOMENTUM report, nausea occurred in 25.5%, 59.6%, and 51.5% of the 1.2 mg, 1.8 mg, and 2.4 mg groups versus 11.3% with placebo. Adverse events led to treatment discontinuation in 5.1%, 19.2%, and 19.6% of those groups versus 6.2% with placebo.
- Trial participants were selected and followed for limited periods. Rare adverse effects, long-term outcomes, and risks in populations not represented in these studies remain uncertain.
Product quality
Product identity and quality
Clinical evidence belongs to the studied product and trial conditions. It cannot verify a vial or other product obtained outside that setting.
Identity and strength
A label alone does not establish the substance or amount in a product.
Sterility and handling
Contamination, storage, and transport can affect an injectable product independently of trial results.
Oversight
Trial screening, monitoring, and reporting do not automatically accompany non-trial use.
Mechanism
How it is proposed to work
Pemvidutide is designed to signal through GLP-1 and glucagon receptors. Researchers are testing whether those combined signals can affect appetite, body weight, and liver metabolism.
GLP-1 signaling is associated with appetite and glucose regulation.
Glucagon receptor activity is being studied for effects on energy and liver-fat metabolism.
Receptor activity is a proposed explanation, not a separate demonstration of patient benefit.
FAQ
Common questions
Is pemvidutide approved in the United States or European Economic Area?
No matching FDA-approved product or EEA authorized product was found in the databases searched. The developer describes pemvidutide as investigational; development designations are not approval.
Did pemvidutide reverse liver fibrosis in IMPACT?
The 24-week analysis did not find a statistically significant improvement on the separate endpoint of fibrosis improvement without worsening MASH. The MASH resolution endpoint did favor pemvidutide.
Details
Technical details
Sources
References
- 1.
PubMed. Safety and efficacy of weekly pemvidutide versus placebo for MASH: IMPACT phase 2b study
doi:10.1016/S0140-6736(25)02114-2 PMID:41237796 NCT05989711
Peer-reviewed 24-week biopsy endpoints and safety from the phase 2b IMPACT trial.
- 2.
Altimmune. IMPACT phase 2b MASH trial: 48-week topline results
NCT05989711
Sponsor-reported 48-week non-invasive outcomes, weight change, and safety; not a 48-week biopsy report.
- 3.
PubMed Central. Safety and efficacy of 24 weeks of pemvidutide in metabolic dysfunction-associated steatotic liver disease
doi:10.1016/j.jhepr.2025.101483 PMID:41113119 NCT05292911
Peer-reviewed 12-week extension of a randomized MASLD study; the primary endpoint was MRI-measured liver fat.
- 4.
PubMed. Effect of pemvidutide on MASLD: a randomized, double-blind, placebo-controlled study
doi:10.1016/j.jhep.2024.07.006 PMID:39002641 NCT05006885
The parent study reports a four-week titration for the 2.4 mg group and no titration for the 1.2 mg and 1.8 mg groups.
- 5.
Altimmune. MOMENTUM phase 2 obesity trial: 48-week topline results
NCT05295875
Sponsor-reported topline results and safety table, not a full peer-reviewed trial report.
- 6.
ClinicalTrials.gov. MOMENTUM study of ALT-801 in obesity
NCT05295875
Registry entry identifies the randomized study arms and subcutaneous route.
- 7.
Altimmune. RECLAIM phase 2 alcohol use disorder trial: topline results
NCT06987513
Sponsor-reported topline results in adults with alcohol use disorder and overweight or obesity.
- 8.
ClinicalTrials.gov. RECLAIM study of pemvidutide in alcohol use disorder
NCT06987513
Registry entry identifies the active arm, weekly frequency, and subcutaneous route.
- 9.
ClinicalTrials.gov. PERFORMA phase 3 study of pemvidutide in MASH
NCT07795164
Registry lists a recruiting phase 3 study; registration is not a results report.
- 10.
ClinicalTrials.gov. RESTORE phase 2 study of pemvidutide in alcohol-associated liver disease
NCT07009860
Registry lists an active, not recruiting trial in alcohol-associated liver disease.
- 11.
Altimmune. Altimmune development pipeline
Developer status statement and description of FDA development designations.
- 12.
FDA. openFDA Drugs@FDA database
Search of active ingredient names returned no pemvidutide match; database results are not a substitute for a regulator decision.
- 13.
EMA. EMA Article 57 authorized product data
The periodically updated EEA authorized-product dataset was searched for pemvidutide and ALT-801; no match was found in the available snapshot.