Pemvidutide
Pemvidutide is an investigational weekly injection from Altimmune that targets GLP-1 and glucagon. Its phase 3 trial is in fatty liver disease (MASH). It is not approved.
Pemvidutide (formerly ALT-801)
Also searched as: ALT-801.
Educational information. This page does not give dosing instructions or tell you what to take. Ask a prescriber about your own care.
In plain English
Pemvidutide (also ALT-801) is a once-weekly injection from Altimmune that activates the GLP-1 and glucagon receptors. Glucagon is thought to act on the liver, which is why the company's main focus is fatty liver disease (MASH) rather than obesity.
In MOMENTUM, a 48-week phase 2 obesity trial reported by the company in November 2023, 391 adults without diabetes lost an average of 10.3% to 15.6% of body weight on three weekly amounts, versus 2.2% on placebo. About one in five people on the two higher amounts stopped because of side effects. This atlas found no journal paper for that trial, and no phase 3 obesity trial is registered.
In the IMPACT phase 2b trial (published in The Lancet in 2025), 52% to 58% of people with MASH and moderate to advanced scarring (stage F2 or F3) who took pemvidutide had their MASH resolve at 24 weeks without worse scarring, versus 20% on placebo. Scarring itself did not improve significantly. Altimmune started the phase 3 PERFORMA trial in August 2026. Pemvidutide is not approved anywhere.
Brand names and products
A generic name identifies the drug itself. A brand name identifies one company's product. One drug can come in several products with different forms and approved uses, so the brand name often tells you more about what a prescription is for.
No brand name is recorded for this medicine because there is no approved product.
Approved and investigational. Every use of pemvidutide is investigational. There is no approved product.
How it works
Pemvidutide is a peptide that activates the GLP-1 receptor, which lowers appetite and slows stomach emptying, and the glucagon receptor, which acts on the liver and may raise energy use. Altimmune is mainly developing it for MASH, where liver fat is the target. Survodutide and mazdutide use the same two-receptor design, and retatrutide adds a third target.
Forms and approval status
| Form | How it is taken | U.S. status |
|---|---|---|
| Pemvidutide injection (investigational) | Once weekly in trials. Available only inside clinical trials. | Not approved. Altimmune began enrolling PERFORMA, a phase 3 trial in adults with MASH (about 1,790 people), in August 2026. The registry lists a primary completion date of December 2028. The company says it holds FDA Breakthrough Therapy and Fast Track designations for MASH. Phase 2 trials in alcohol use disorder (RECLAIM) and alcohol-associated liver disease (RESTORE) are also registered. This atlas found no phase 3 obesity trial. |
What the trials found
These are group averages from published trials in adults without diabetes unless stated. See how to read trial numbers before comparing.
MOMENTUM (pemvidutide, obesity)
Average change in body weight. Every bar uses one scale, 0 to 25 percent.
- People studied
- 391 adults with obesity, or overweight plus at least one weight-related condition, without diabetes
- Length
- 48 weeks
- Compared with
- Placebo, with diet and exercise in all groups. Pemvidutide 1.2 mg and 1.8 mg weekly with no dose increase, and 2.4 mg weekly after a four-week increase
- What was measured
- Average change in body weight at week 48, as reported by the company
- Analysis approach
- Not stated in the company announcement
- Other results
- On 2.4 mg, the company says more than half of people lost at least 15% of body weight and more than 30% lost at least 20%.
- Safety
- Nausea and vomiting were the most common side effects, mostly mild or moderate. Stopping because of side effects: 6.2% on placebo, 5.1% on 1.2 mg, 19.2% on 1.8 mg and 19.6% on 2.4 mg. One drug-related serious event was reported (vomiting on 2.4 mg).
- Limits
- These figures come from a company press release. This atlas did not find a peer-reviewed paper for the trial. The 2.4 mg group used a different dose-increase approach, so it differs from the others in more than amount. About one in five people on the two higher amounts stopped because of side effects. No phase 3 obesity trial is registered.
Safety
No FDA label exists for this medicine yet. The information below comes from published trial reports. The points below are a summary and may be incomplete.
Boxed warning and label notes
- Pemvidutide injection (investigational): Not applicable. Not approved.
Warnings labels describe
- Not approved, so no official label exists. Safety information comes from one published phase 2b trial and company announcements.
- Because it activates the GLP-1 receptor, the safety points seen with that class are expected to be relevant, but no label exists to say so.
Most common in trials
- Nausea and vomiting, mostly mild to moderate
- In the MASH trial, side effects of any kind were reported by 78% to 81% of people on pemvidutide vs 67% on placebo
Less common but serious
- MOMENTUM: the company reported one drug-related serious event, vomiting on the highest amount.
- IMPACT: stopping because of side effects was rare (none at 1.2 mg, 1% at 1.8 mg and 2% on placebo).
What is still unknown
- Whether pemvidutide will be taken into a phase 3 obesity trial. None is registered.
- Phase 3 MASH results. The company expects the first 52-week readout in 2029.
- Whether it improves liver scarring. The 24-week phase 2b trial did not meet that goal, and the company's 48-week report covers non-invasive markers rather than biopsy.
- Results of the RECLAIM alcohol-use trial. The registry lists it as complete, and none were found.
- Long-term safety beyond 48 weeks.
- How it compares with other GLP-1 and glucagon drugs. No head-to-head trial exists.
Compiled from public information: FDA-approved labels, manufacturer websites, ClinicalTrials.gov and published journal articles. Sources are listed at the bottom of this page.
Sources
- 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 Noureddin M, et al. Lancet. 2025;406(10520):2644-2655. PMID 41237796. Funding: Altimmune. Journal article
- Altimmune announces positive topline results from MOMENTUM 48-week phase 2 obesity trial of pemvidutide Altimmune press release, November 30, 2023. Company announcement; not peer reviewed. Trade press, secondary source
- Altimmune initiates PERFORMA phase 3 trial of pemvidutide in patients with MASH Altimmune press release, August 3, 2026, via BioSpace. Company announcement; not peer reviewed. Trade press, secondary source
- Altimmune full-year 2025 results and business update (Form 8-K exhibit) Altimmune press release filed with the SEC, March 2026. Company announcement; not peer reviewed. Trade press, secondary source
- Pemvidutide phase 3 in non-cirrhotic MASH (NCT07795164) ClinicalTrials.gov identifier NCT07795164. Sponsor: Altimmune. Trial registry
- RECLAIM: pemvidutide phase 2 in alcohol use disorder with obesity or overweight (NCT06987513) ClinicalTrials.gov identifier NCT06987513. Sponsor: Altimmune. Trial registry
- RESTORE: pemvidutide phase 2 in alcohol-associated liver disease (NCT07009860) ClinicalTrials.gov identifier NCT07009860. Sponsor: Altimmune. Trial registry
- ClinicalTrials.gov U.S. National Library of Medicine. Trial registry