Peptide Schedule
Pemvidutide (ALT-801)Small moleculeNo amino acid sequence. Icon reflects category theme only.Pemvidutide (ALT-801)
Benefits
About Pemvidutide (ALT-801)
Pemvidutide (ALT-801) is a dual GLP-1 and glucagon receptor agonist developed by Altimmune for obesity and MASH (metabolic dysfunction-associated steatohepatitis). Unlike GLP-1-only drugs such as semaglutide, pemvidutide activates both the GLP-1 receptor and the glucagon receptor in a balanced 1:1 ratio. This dual mechanism means it suppresses appetite through GLP-1 activity while simultaneously increasing hepatic fat oxidation and energy expenditure through glucagon receptor activation — a combination that drives both weight loss and direct liver fat reduction. The Phase 2 MOMENTUM trial (48 weeks, 391 participants with obesity) showed dose-dependent weight loss: 10.3%, 11.2%, and 15.6% at the 1.2mg, 1.8mg, and 2.4mg weekly doses respectively, compared to 2.2% with placebo. Weight loss on the 2.4mg dose was still following a near-linear trajectory at week 48, suggesting the plateau had not yet been reached. Body composition analysis showed 78.1% of weight lost was fat mass, with only 21.9% lean mass loss — a ratio Altimmune describes as class-leading among GLP-1 class drugs. The liver fat data is where pemvidutide stands out most clearly. In the MASLD extension study, 24 weeks of treatment produced liver fat reductions of 56.3%, 75.2%, and 76.4% at the 1.2mg, 1.8mg, and 2.4mg doses. The IMPACT Phase 2b trial in biopsy-confirmed MASH patients (F2-F3 fibrosis) confirmed these effects, with 45.2% and 54.7% liver fat reductions at 1.2mg and 1.8mg at 24 weeks. These results position pemvidutide alongside survodutide as one of the most promising dual agonists for fatty liver disease. Pemvidutide uses Altimmune's proprietary EuPort domain technology, which binds albumin to extend the half-life for weekly dosing and slows entry into the bloodstream, potentially improving GI tolerability. Clinical development is ongoing with Phase 2b/3 trials planned.
Who Should Consider Pemvidutide (ALT-801)
- Adults with BMI ≥30 (obesity)
- Adults with BMI ≥27 with weight-related comorbidities
- Patients with MASH/NASH and liver fibrosis (F2-F3)
- Patients with metabolic dysfunction-associated steatotic liver disease (MASLD)
- Adults seeking combined weight loss and liver fat reduction
- Patients who may benefit from dual GLP-1/glucagon agonism over GLP-1-only therapy
How Pemvidutide (ALT-801) Works
Pemvidutide is a balanced (1:1) dual agonist of the GLP-1 receptor and glucagon receptor. GLP-1 receptor activation reduces appetite, slows gastric emptying, and enhances glucose-dependent insulin secretion from pancreatic beta cells. Glucagon receptor activation increases hepatic fatty acid oxidation, promotes lipolysis, and raises energy expenditure through thermogenesis. The combination produces both significant weight loss and direct liver fat reduction — an effect that GLP-1-only agonists achieve only indirectly through weight loss. Pemvidutide incorporates Altimmune's EuPort domain, a proprietary albumin-binding technology that extends the circulating half-life to support once-weekly dosing and slows the rate of entry into the bloodstream, which may reduce peak-related GI side effects. In preclinical models, ALT-801 showed a delayed Tmax compared to semaglutide, consistent with this controlled-release mechanism.
What to Expect
Starting dose (1.2mg weekly). Early appetite suppression begins. GI side effects (nausea, decreased appetite) are most common in the first few weeks. Minimal weight change expected during this adjustment period.
Dose may be increased to 1.8mg or 2.4mg based on tolerability. Appetite reduction becomes more pronounced. Early weight loss of 3-5% body weight. GI symptoms typically stabilize. Measurable liver fat reduction already occurring.
Steady weight loss continues at a near-linear rate. MASLD studies showed 56-76% liver fat reduction by week 24. Improvements in triglycerides, cholesterol, and blood pressure begin to appear on lab work.
Continued weight loss approaching 10-15% depending on dose. MOMENTUM showed 15.6% weight loss at 48 weeks on 2.4mg with trajectory still declining. Body composition shifts toward greater fat loss with preserved lean mass. Full metabolic benefits evident.
Dosing Protocol
| Level | Dose / Injection | Frequency |
|---|---|---|
| Beginner | 1.2mg | Weekly |
| Moderate | 1.8mg | Weekly |
| Aggressive | 2.4mg | Weekly |
Note: Dual GLP-1/glucagon receptor agonist by Altimmune. Phase 2 data shows 15.6% weight loss and up to 78.6% liver fat reduction at 2.4mg weekly. No dose titration required in trials, though starting at 1.2mg is recommended. Pre-filled pen format used in clinical trials.
How to Inject Pemvidutide (ALT-801)
Inject subcutaneously once weekly into the abdomen, thigh, or upper arm. Rotate injection sites each week. In clinical trials, pemvidutide was administered via pre-filled pen without a mandatory titration schedule. Starting at 1.2mg weekly and increasing to 1.8mg or 2.4mg based on tolerability is a reasonable approach. Inject on the same day each week. Store in the refrigerator and allow to reach room temperature before injection.
Cycling Protocol
Based on MOMENTUM Phase 2 trial duration (48 weeks). Long-term maintenance data beyond 48 weeks is not yet available. Weight regain is expected after discontinuation, as with other GLP-1 class drugs.
Pharmacokinetics
Source: Estimated ~4-6 days based on weekly dosing schedule and EuPort albumin-binding domain; exact human t½ not publicly disclosed. Preclinical mouse MRT ~22h (Nestor et al., PMID 35461369)
Loading the interactive decay curve.
Side Effects
GI side effects are the most common, consistent with the GLP-1 drug class. Nausea was reported in up to 52% of participants at the 2.4mg dose in MOMENTUM, with vomiting at 28%, constipation at 23%, and diarrhea at 19%. Most GI events were mild to moderate and tended to decrease over time. Discontinuation due to adverse events was 16-20% at the higher doses. Small heart rate increases of 2-3 bpm were observed at higher doses, but no imbalance in arrhythmias or major adverse cardiac events was reported. Drug-related serious adverse events were rare (about 1% at the 2.4mg dose). Decreased appetite is expected and part of the mechanism.
Contraindications
- Personal or family history of medullary thyroid carcinoma (MTC)
- Multiple Endocrine Neoplasia syndrome type 2 (MEN2)
- History of pancreatitis or active pancreatitis
- Pregnancy or planning to become pregnant
- Breastfeeding
- Known hypersensitivity to pemvidutide or any excipients
- Severe gastrointestinal disease (e.g., gastroparesis)
- Decompensated liver disease or cirrhosis (limited data)
Drug Interactions
- Insulin and sulfonylureas — increased hypoglycemia risk; dose adjustment may be needed
- Other GLP-1 receptor agonists (semaglutide, tirzepatide, liraglutide) — do not combine; overlapping mechanism
- Oral contraceptives — reduced efficacy possible due to delayed gastric emptying; consider barrier method
- Oral medications with narrow therapeutic index (e.g., warfarin, levothyroxine) — monitor closely due to altered gastric emptying
- Glucagon for hypoglycemia rescue — may have reduced effectiveness due to glucagon receptor competition
Storage & Stability
Related Peptides
References
- Effect of pemvidutide on MASLD: A randomized, double-blind, placebo-controlled study (J Hepatol)PubMed 39002641
- Safety and efficacy of 24 weeks of pemvidutide in MASLD (JHEP Rep 2025)PubMed 41113119
- IMPACT Phase 2b: Pemvidutide vs placebo for MASH — 24-week results (Lancet 2025)PubMed 41237796
- Effects of ALT-801 in a translational mouse model of NASH (Sci Rep 2022)PubMed 35461369
- MOMENTUM Phase 2 — 48-week topline results (Altimmune press release)Review
- MOMENTUM Phase 2 — ADA 84th Scientific Sessions oral presentationReview