Clinical Trials Pipeline & In-Development

Pemvidutide

also known as: ALT-801

Altimmune's GLP-1 / glucagon co-agonist — received FDA Breakthrough Therapy Designation for MASH in January 2026 after positive IMPACT Phase 2b antifibrotic data, with Phase 3 initiation planned for 2026.

A balanced (1:1) dual glucagon and GLP-1 receptor agonist developed by Altimmune for once-weekly subcutaneous administration, being investigated for both chronic weight management and metabolic dysfunction-associated steatohepatitis (MASH), and granted FDA Breakthrough Therapy Designation for MASH on January 5, 2026.

Mechanism of action

Simultaneously activates the GLP-1 receptor (driving appetite suppression, delayed gastric emptying, and insulin-related metabolic effects) and the glucagon receptor (driving hepatic fat oxidation, increased energy expenditure, and direct effects on hepatocyte lipid metabolism). The 1:1 balanced dual agonism is designed to capture the weight loss of GLP-1 while adding glucagon-driven hepatic benefits — particularly relevant for MASH where liver-specific fat reduction is central to the therapeutic target.

Primary uses

MASH with moderate-to-advanced fibrosis (Phase 3 planned 2026, Breakthrough Therapy Designation)
Chronic weight management (Phase 2 completed)

Typical dosing

1.2–2.4 mg once weekly (subcutaneous)

IMPACT Phase 2b tested 1.2 mg and 1.8 mg doses in MASH; Phase 3 doses TBD.

Regulatory status

Not approved. Altimmune developer. FDA Breakthrough Therapy Designation for MASH granted January 5, 2026. IMPACT Phase 2b MASH trial (48-week data released December 19, 2025) showed statistically significant improvements in non-invasive fibrosis markers (ELF, LSM) versus placebo across multiple doses. A registrational Phase 3 MASH trial is planned for initiation in 2026 using AIM-MASH AI Assist pathology scoring. Earlier MOMENTUM Phase 2 obesity trial showed ~15% weight loss at 48 weeks.

References

[news-release] Altimmune, Inc. "Altimmune Receives FDA Breakthrough Therapy Designation for Pemvidutide in MASH." January 5, 2026.
[news-release] Altimmune, Inc. "Altimmune Announces that Pemvidutide Achieved Key Measures of Success at 48 Weeks in IMPACT Phase 2b MASH Trial." December 19, 2025.

Related peptides

Semaglutide

A once-weekly GLP-1 receptor agonist FDA-approved for type 2 diabetes and chronic weight management.

Retatrutide

An investigational triple hormone agonist that produced ~24% weight loss at 48 weeks in Phase 2 — the largest in any single-agent obesity trial to date.

Survodutide

A once-weekly GLP-1/glucagon co-agonist in late-stage trials for obesity, type 2 diabetes, and MASH.

Tirzepatide

A once-weekly GLP-1/GIP dual agonist that produced unprecedented weight loss in SURMOUNT trials — up to ~21% at highest dose.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.