Pemvidutide is an investigational once-weekly injection from Altimmune that activates the GLP-1 and glucagon receptors in equal balance, with a focus on fatty liver disease.[5] In the phase 2b IMPACT trial, it resolved MASH in up to 58% of patients versus 20% on placebo, though it did not significantly improve liver scarring.[1] It has FDA Breakthrough Therapy designation for MASH and entered phase 3 in 2026.[6][7]

How pemvidutide works

Glucagon receptor activation acts directly on the liver, increasing fat burning and reducing fat production, while GLP-1 activation reduces appetite.[2][5]

Pemvidutide results

Fatty liver disease

  • IMPACT design: 212 adults with biopsy-confirmed MASH and moderate or advanced scarring (F2 or F3) at 83 sites in the US and Australia took 1.2 mg, 1.8 mg or placebo. More than 1,500 people were screened to find them.[1]
  • IMPACT (24 weeks): MASH resolved without worsening fibrosis in 58% (1.2 mg) and 52% (1.8 mg) versus 20% on placebo. Fibrosis improved in 33% to 36% versus 28%, a difference that was not statistically significant.[1]
  • 48 weeks (company-reported): non-invasive tests of liver scarring and stiffness improved, and weight fell up to 7.5%.[5] Liver fat fell 45.2% to 54.7% versus 8.2% on placebo, and the liver enzyme ALT fell by about 37 units versus 10. Blood and scan markers of scarring (ELF score and liver stiffness) also improved more than on placebo. These are not biopsy results, and they have not been peer reviewed.[5]
  • Liver fat: in 12 weeks, liver fat fell by up to 68.5% versus 4.4% on placebo,[2] and by up to 76.4% at 24 weeks.[3]
  • Normal liver fat: in the 12-week study of 94 adults (average BMI 36.2, 29% with type 2 diabetes), 55.6% on 1.8 mg reached normal liver fat levels, and no severe or serious side effects were reported.[2] In the 64 people who continued to 24 weeks, 53.8% on 1.8 mg had normal liver fat and weight fell 6.2%.[3]

Weight loss

In the 48-week MOMENTUM trial, weight fell 10.3% to 15.6% depending on dose versus 2.2% on placebo. These company-reported results have not been published in a peer-reviewed journal.[4]

The 391 participants started at an average BMI of about 37 and weight of about 104 kg, and about 75% were women. On the top 2.4 mg dose, 51.8% of people with follow-up data lost at least 15% of their weight and 32.1% lost at least 20%. Triglycerides fell by up to 34.9%, and blood sugar and HbA1c did not change meaningfully in this group without diabetes.[4]

Lean mass claims

Altimmune reported that only 21.9% of weight lost was lean mass in an MRI substudy of 50 people, which it described as class-leading. There was no placebo comparison, and the data are company-presented and not peer reviewed.[8]

Other uses being studied

  • Alcohol use disorder (RECLAIM): 100 adults with obesity or overweight took 2.4 mg or placebo for 24 weeks. The main goal was fewer heavy drinking days per week.[12] Altimmune reported in July 2026 that this goal was met, but full results are not yet peer reviewed.[6]
  • Alcohol-associated liver disease (RESTORE): 121 adults took 2.4 mg or placebo, with liver stiffness at 48 weeks as the main goal. Altimmune expects topline results in the second half of 2027.[13][6]

Pemvidutide vs survodutide and mazdutide

All three are GLP-1 and glucagon dual agonists. Mazdutide is approved in China; survodutide has phase 3 obesity and liver results; pemvidutide is earlier in development and focused on MASH. No head-to-head trials exist.

Pemvidutide side effects

  • Stopping treatment: in MOMENTUM, 19.2% and 19.6% stopped due to side effects on the two higher doses, versus 6.2% on placebo.[4]
  • In IMPACT, side effects were more common than placebo (78% to 81% vs 67%) but few people stopped (0% to 1%).[1]
  • Heart rate: the company reported no clinically meaningful increases; average changes ranged from 0.1 to 3.1 beats per minute versus a 1.4 drop on placebo. This is company-reported only.[4]
  • Timing: in MOMENTUM, nausea and vomiting were the most common side effects, and most stops due to side effects happened in the first 16 weeks.[4]
  • 48-week IMPACT data: 0% and 1.2% stopped because of side effects, versus 3.5% on placebo, according to the company.[5]

Pemvidutide dosage: what has been studied

IMPACT used 1.2 mg or 1.8 mg once weekly with no dose titration; MOMENTUM tested up to 2.4 mg after a 4-week titration.[1][4] No dose is approved.

Is pemvidutide approved?

  • Not approved anywhere. The phase 3 PERFORMA trial in 1,800 people with MASH began in July 2026, with results expected in 2029.[6][9] It compares 1.8 mg and 2.4 mg with placebo in people with F2 or F3 scarring but no cirrhosis. Liver biopsies at 52 weeks come first, and the trial then follows liver-related outcomes for about five years.[9]
  • FDA designations: Breakthrough Therapy for MASH, plus Fast Track for MASH and alcohol use disorder.[6]
  • Not on FDA’s compounding lists, and unapproved drugs fall under WADA’s non-approved substances category.[11][10]

Questions to ask a clinician

Pemvidutide is only available in clinical trials. If you have fatty liver disease, useful questions include:

  • What stage is my liver scarring, and how is it being monitored?
  • Would an approved option, such as semaglutide or tirzepatide, help my liver and weight now?
  • Am I eligible for a MASH or alcohol-related trial nearby?

This is general information, not legal advice.