What Is Pemvidutide?

1. What Is Pemvidutide?

Pemvidutide is an investigational molecule developed by Altimmune (Nasdaq: ALT). Its development code name is ALT-801. It is a once-weekly subcutaneous peptide designed to activate two receptors: the receptor for glucagon-like peptide-1 (GLP-1) and the glucagon receptor.

This is a different pairing from the GLP-1/GIP combination used by tirzepatide. Pemvidutide belongs to the GLP-1/glucagon family, alongside survodutide and a handful of other molecules.

For receptor-language background, see What Is a GLP-1?.

2. Why a GLP-1/Glucagon Dual Agonist?

Altimmune describes pemvidutide as a “balanced” agonist, with roughly equal (1:1) potency at the GLP-1 and glucagon receptors. The two arms are designed to do different jobs:

• GLP-1 arm: suppresses appetite and increases satiety, the mechanism associated with weight loss.
• Glucagon arm: acts directly on the liver to increase fat oxidation and energy expenditure, the rationale for studying it in liver disease and for its reported tendency to preserve lean mass.

3. Is Pemvidutide FDA-Approved?

No. Pemvidutide is not FDA-approved as of June 2026. It is investigational, has no marketed product, and is available only through Altimmune clinical trials. It did receive FDA Breakthrough Therapy Designation for MASH in January 2026, which is a designation intended to speed development; it is not an approval.

4. What Did the IMPACT MASH Trial Show?

IMPACT (NCT05989711) was a Phase 2b trial in adults with biopsy-confirmed MASH and fibrosis. Altimmune reported that at 24 weeks, a significantly higher proportion of pemvidutide-treated participants achieved MASH resolution without worsening of fibrosis compared with placebo, meeting the primary endpoint. At 48 weeks, the company reported continued improvement in non-invasive markers of liver fibrosis. The 24-week results were published in The Lancet in December 2025.

These outcomes apply to a defined trial population and do not guarantee similar results for anyone else.

5. What About Obesity?

Pemvidutide’s Phase 2 obesity trial was MOMENTUM (NCT05295875), in adults with overweight or obesity without type 2 diabetes. Altimmune reported mean weight loss in the highest-dose arm of roughly 15.6% at 48 weeks versus about 2.2% for placebo, with a high proportion of the weight lost being fat rather than lean mass in an imaging sub-study. The company has reported completing an end-of-Phase-2 meeting with the FDA for the obesity program.

6. Pemvidutide vs Survodutide vs GLP-1/GIP Drugs

Pemvidutide is frequently compared with other dual agonists. The key axis is which second receptor is paired with GLP-1, and the balance between them.

• Pemvidutide vs survodutide: Both are GLP-1/glucagon agonists. Pemvidutide is described as balanced roughly 1:1; survodutide is generally described as more GLP-1-weighted. Cross-trial comparisons are not head-to-head and differ in endpoints and populations.
• Pemvidutide vs GLP-1/GIP drugs (e.g. tirzepatide): Those pair GLP-1 with the incretin hormone GIP and have no glucagon component, so they lack the direct liver-targeted glucagon mechanism that underpins pemvidutide’s MASH rationale.

7. Where Pemvidutide Stands

• Pemvidutide is the molecule; ALT-801 is its code name.
• Investigational describes its regulatory status.
• Balanced GLP-1/glucagon receptor agonist is the accurate mechanism description.
• MASH is the lead program, with obesity and alcohol-related conditions also under study.

8. What Is Pemvidutide FAQ

• What is pemvidutide in simple terms?

  Pemvidutide is Altimmune's investigational once-weekly injection that activates two receptors: GLP-1 and glucagon. The GLP-1 arm is linked to appetite and weight; the glucagon arm acts on the liver, which is why the lead focus is the liver disease MASH.

• Is pemvidutide FDA-approved?

  No. Pemvidutide is investigational and not approved by the FDA or any regulator as of June 2026. It is available only to participants in Altimmune clinical trials.

• Why does pemvidutide include a glucagon receptor target?

  Glucagon receptor activation acts directly on the liver to increase fat oxidation and energy expenditure. This is the mechanistic rationale for studying pemvidutide in MASH and for its reported lean-mass preservation in obesity trials.

• What is the difference between pemvidutide and survodutide?

  Both are GLP-1/glucagon dual agonists. Altimmune describes pemvidutide as balanced roughly 1:1 between the two receptors, while survodutide is generally described as more GLP-1-weighted. They are separate molecules from different companies in separate trials.

• What did the IMPACT MASH trial report?

  Altimmune's Phase 2b IMPACT trial in biopsy-confirmed MASH reported that more pemvidutide-treated participants achieved MASH resolution without worsening of fibrosis at 24 weeks than placebo, with continued improvement in non-invasive fibrosis markers at 48 weeks. These are trial findings, not an approval.

9. Sources