Pemvidutide is an experimental weekly injection from the US biotech Altimmune that activates two receptors at once: GLP-1, like Ozempic and Wegovy, and glucagon, which acts directly on the liver. In 2023 it produced 15.6% average weight loss at 48 weeks in an obesity trial. Altimmune then moved it away from obesity: its phase 3 trial is in the fatty-liver disease MASH, and in July 2026 it reported a positive trial in alcohol use disorder. It is not approved anywhere.
Everything below was read on 26 October 2026 from Altimmune's own press releases as filed with the US Securities and Exchange Commission, the published trials on PubMed and the ClinicalTrials.gov registry. The SEC copies are used because they are the versions the company is legally answerable for.
The pivot, in the company's words
Altimmune's July and August 2026 filings describe it as "a late clinical-stage biopharmaceutical company focused on serious liver diseases" developing pemvidutide for MASH, alcohol use disorder (AUD) and alcohol-associated liver disease (ALD). Obesity is not on the list. That matters for anyone who finds pemvidutide in a list of "next GLP-1 weight-loss drugs": as of today, no obesity phase 3 trial is registered, and the company has not said it plans one.
The reason it is still searched as a weight-loss drug is the obesity trial it ran first.
MOMENTUM: the obesity result that is still quoted
Altimmune's 8-K of 30 November 2023 reported the 48-week MOMENTUM phase 2 trial: 391 adults with obesity or overweight and at least one related condition, no diabetes, about 75% women, mean BMI about 37.
| Arm | Mean weight loss at 48 weeks | Stopped treatment for adverse events |
|---|---|---|
| Placebo | 2.2% | 6.2% |
| 1.2 mg | 10.3% | 5.1% |
| 1.8 mg | 11.2% | 19.2% |
| 2.4 mg | 15.6% | 19.6% |
The 15.6% is the number that travels. The column beside it rarely does: about one in five people on the two higher doses stopped because of side effects, against about one in sixteen on placebo, most of them in the first 16 weeks. The 1.2 and 1.8 mg doses were given with no dose titration at all, and the 2.4 mg dose with only four weeks of it; the approved weekly GLP-1 drugs step up over months. Whether the fast start explains the dropouts is not tested in the release, and the 2026 RECLAIM trial used what Altimmune calls a new two-step titration. The release also reports no significant change in HbA1c or fasting glucose, and no imbalance in cardiac events. This trial has not, as far as a PubMed search shows, been published as a full paper.
IMPACT: the liver trial
IMPACT (NCT05989711) is the trial the company's direction now rests on. It randomised 212 adults with biopsy-confirmed MASH and moderate-to-advanced fibrosis (stage F2 or F3) at 83 sites in the US and Australia to pemvidutide 1.2 mg, 1.8 mg or placebo — again with no titration. The 24-week results were published in The Lancet in December 2025.
| 24-week endpoint | Placebo (86) | 1.2 mg (41) | 1.8 mg (85) |
|---|---|---|---|
| MASH resolution, fibrosis not worse | 18 (20%) | 24 (58%) | 45 (52%) |
| Fibrosis improved ≥1 stage, MASH not worse | 24 (28%) | 13 (33%) | 30 (36%) |
| Any adverse event | 67% | 78% | 81% |
| Stopped for adverse events | 2% | 0% | 1% |
The trial met one of its two primary endpoints. MASH resolution was clearly better than placebo (p<0.0001 for both doses); fibrosis improvement was not (p=0.59 and p=0.27). The authors say so plainly, and longer trials were planned.
Altimmune's 8-K of 19 December 2025 added the 48-week readout, which used non-invasive tests rather than a second biopsy: liver stiffness fell by 3.04 and 3.97 units against 0.03 on placebo, the ELF fibrosis score by 0.49 and 0.58 against a rise of 0.16, and liver fat by 45.2% and 54.7% against 8.2%. Weight fell 4.5% and 7.5% against 0.2% — lower than in MOMENTUM because these doses were lower. Non-invasive markers correlate with biopsy findings but are not the same thing; the fibrosis question is what phase 3 has to answer. The approved liver option in this class, Wegovy for MASH, is set out on our GLP-1 and fatty liver page.
RECLAIM: alcohol use disorder
The newest result is from RECLAIM, a 24-week phase 2 trial in 100 adults with moderate-to-severe alcohol use disorder and obesity or overweight, reported in Altimmune's 8-K of 28 July 2026.
| 24-week measure | Placebo | Pemvidutide 2.4 mg | p |
|---|---|---|---|
| Change in heavy drinking days per week (primary) | -2.75 | -4.20 | 0.0014 |
| Two-level drop in WHO risk drinking level | 34.8% (16/46) | 64.4% (29/45) | 0.0049 |
| No heavy drinking days, weeks 21–24 | 17.4% (8/46) | 42.2% (19/45) | 0.0066 |
| Weight, difference from placebo | — | -9.1% | <0.0001 |
The side-effect table in the same filing:
| Event | Placebo (50) | Pemvidutide (50) |
|---|---|---|
| Nausea | 24% | 44% |
| Constipation | 6% | 26% |
| Diarrhoea | 10% | 20% |
| Vomiting | 6% | 18% |
| Serious adverse events | 2% | 4% |
| Stopped for a drug-related adverse event | 0% | 10% |
Note the placebo group: heavy drinking days fell by almost three a week without the drug, which is common in alcohol trials, where enrolment itself changes behaviour. The drug's effect is the gap, 1.45 heavy drinking days a week. Drinking was self-reported; the blood marker PEth, which measures alcohol intake objectively, also fell. One serious adverse event — low blood sodium — was judged possibly drug-related. No paper has been published; these are the company's topline figures. What is known about the approved GLP-1 drugs and drinking is on our GLP-1 and alcohol page.
What is running now
On 26 October 2026 ClinicalTrials.gov listed eight studies under the name pemvidutide and sixteen under its code ALT-801 (the code search also catches an unrelated cancer drug that once used the same code).
| Registry number | Phase | Who | Size | Status / primary completion |
|---|---|---|---|---|
| NCT07795164 (PERFORMA) | 3 | MASH | 1,800 planned | Recruiting; December 2028 (est.) |
| NCT07009860 (RESTORE) | 2 | Alcohol-associated liver disease | 121 | Active, not recruiting; September 2027 (est.) |
| NCT06987513 (RECLAIM) | 2 | Alcohol use disorder | 100 | Completed July 2026; no results posted |
| NCT05989711 (IMPACT) | 2b | MASH, F2–F3 | 212 | Completed; Lancet 2025 |
Altimmune's Q2 2026 filing (12 August 2026) says PERFORMA has started and that its 52-week data readout is anticipated in 2029, and that RESTORE has finished enrolling. The same filing states that FDA granted Breakthrough Therapy designation for MASH on the 24-week IMPACT data, and Fast Track designations for MASH and AUD.
Where it sits in the class
Pemvidutide belongs to the glucagon co-agonist group with Boehringer Ingelheim's survodutide and mazdutide, a Lilly molecule developed in China by Innovent; Lilly's retatrutide adds GIP to the same pair. The rationale is the liver: glucagon receptors there drive fat burning directly, which is why all of these drugs are tested in MASH as well as obesity. The head-to-head that would rank them does not exist, and the trials differ too much in length, population and dose escalation for their headline numbers to be compared. How the two main glucagon co-agonists line up against each other is on our survodutide vs retatrutide page.
What is not established
- Whether it improves fibrosis on biopsy. IMPACT missed that endpoint at 24 weeks; PERFORMA is the test.
- Long-term safety. The longest completed trial is 48 weeks.
- Its place in obesity. No obesity phase 3 is registered, and the 2023 dropout rate on the higher doses has not been answered with a published titration trial.
- The full RECLAIM data. Only a company release exists.
- Price, dose and date. Nothing has been filed.
Questions about liver disease, alcohol use or weight treatment belong with a clinician who knows the person's history.
Sources
- Altimmune, Inc., Form 8-K exhibit 99.1, 30 November 2023 (MOMENTUM 48-week topline), SEC EDGAR. Read 2026-10-26.
- Altimmune, Inc., Form 8-K exhibit 99.1, 19 December 2025 (IMPACT 48-week topline and End-of-Phase 2 meeting), SEC EDGAR. Read 2026-10-26.
- Altimmune, Inc., Form 8-K exhibit 99.1, 28 July 2026 (RECLAIM topline), SEC EDGAR. Read 2026-10-26.
- Altimmune, Inc., Form 8-K exhibit 99.1, 12 August 2026 (second-quarter results; PERFORMA, RESTORE), SEC EDGAR. Read 2026-10-26.
- Noureddin M et al. "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." Lancet 2025;406:2644-2655, PubMed 41237796, doi 10.1016/S0140-6736(25)02114-2. Funded by Altimmune. Read 2026-10-26.
- Harrison SA et al. "Effect of pemvidutide, a GLP-1/glucagon dual receptor agonist, on MASLD: a randomized, double-blind, placebo-controlled study." J Hepatol 2025, PubMed 39002641. Read 2026-10-26.
- ClinicalTrials.gov API v2, intervention search "pemvidutide" (8 records) and term search "ALT-801" (16 records); NCT07795164, NCT07009860, NCT06987513, NCT05989711, clinicaltrials.gov. Read 2026-10-26.