Altimmune, Inc. has reported positive topline results from the Phase 2 RECLAIM trial, showing that once-weekly pemvidutide significantly reduced heavy drinking days in adults with moderate to severe alcohol use disorder and overweight or obesity. Patients receiving the 2.4-milligram dose reduced their average number of heavy drinking days by 4.20 days per week after 24 weeks, compared with a reduction of 2.75 days for placebo, producing a treatment difference of 1.45 days. Pemvidutide also improved clinically relevant secondary measures, including sustained periods without heavy drinking and reductions in World Health Organization risk-drinking levels. The findings support continued development, but they come from approximately 100 selected patients and do not yet establish long-term effectiveness, regulatory approval or benefit in people with alcohol use disorder who do not have excess weight.
Pemvidutide reduced heavy drinking while more patients reached lower-risk consumption levels
RECLAIM was a multicenter, randomized, double-blind and placebo-controlled Phase 2 study. Approximately 100 adults were assigned equally to receive either pemvidutide 2.4 milligrams or placebo by subcutaneous injection once weekly for 24 weeks. Eligible participants had moderate to severe alcohol use disorder and a body mass index above 25 kilograms per square metre, limiting the study to people with overweight or obesity.
The primary endpoint measured the change from baseline in average heavy drinking days per week at Week 24. Pemvidutide-treated patients had a least-squares mean reduction of 4.20 days, compared with 2.75 days in the placebo group. The 1.45-day difference was statistically significant, with a p-value of 0.0014.
The placebo group’s substantial improvement shows that participation in the trial, clinical contact and other study effects influenced drinking behaviour in both arms. Pemvidutide nevertheless produced an additional reduction beyond that response, supporting a pharmacological treatment effect under the study’s statistical model. The release did not disclose baseline heavy drinking frequency, subgroup responses or the distribution of individual patient outcomes, which will be needed to determine how consistently the average benefit was experienced.
Nearly two-thirds of evaluable pemvidutide recipients achieved at least a two-level reduction in World Health Organization risk-drinking category, compared with approximately one-third of placebo recipients. The rates were 64.4% and 34.8%, respectively, corresponding to an odds ratio of 3.31 and a p-value of 0.0049.
A two-level risk reduction does not necessarily require complete abstinence. It measures movement from a higher-risk drinking category to a meaningfully lower one and has been qualified by the FDA as a clinically meaningful drug-development outcome for alcohol use disorder. The agency has identified this measure as another potential endpoint alongside abstinence and the absence of heavy drinking days.
During Weeks 21 through 24, 42.2% of evaluable pemvidutide-treated patients reported no heavy drinking days, compared with 17.4% receiving placebo. Days of abstinence increased by a least-squares mean of 38.9 percentage points with pemvidutide and 20.5 percentage points with placebo. Both differences were statistically significant.
Objective alcohol biomarker results support the self-reported drinking outcomes
Alcohol-consumption studies depend partly on participant reporting, which can be affected by recall errors or the tendency to underreport drinking. RECLAIM therefore included phosphatidylethanol, or PEth, as an objective blood biomarker associated with alcohol exposure.
PEth levels declined by a least-squares mean of 153.4 in the pemvidutide group at Week 24, while the placebo group showed an increase of 22.0. The treatment difference was statistically significant, with a p-value below 0.0001. Altimmune did not provide the complete biomarker distribution, units or relationship between the PEth change and individual clinical outcomes in the topline announcement.
The biomarker finding strengthens the drinking-day results because it points in the same direction as the patient-reported outcomes. It does not independently establish abstinence or reveal how drinking behaviour changed after treatment stopped. Full publication will be necessary to assess missing data, adherence, sensitivity analyses and whether patients with the largest weight loss also experienced the greatest reduction in alcohol consumption.
Pemvidutide produced a placebo-adjusted body-weight reduction of 9.1% after 24 weeks, with Altimmune reporting no evidence of a plateau. Weight loss may be clinically relevant for patients with obesity, fatty liver disease and alcohol-related metabolic risks. However, it also raises questions about whether reduced alcohol intake resulted entirely from altered craving and reward pathways or was partly influenced by broader appetite suppression, gastrointestinal effects or reduced caloric consumption.
The study cannot determine whether the same drinking benefit would occur in people with normal body weight because those patients were not included. Alcohol use disorder affects people across a wide range of body sizes, and future studies will need to clarify whether pemvidutide’s potential role is broad or concentrated among patients who also have obesity or metabolic and liver disease.
Gastrointestinal adverse events and treatment discontinuations remain important
Pemvidutide was associated with the gastrointestinal adverse effects commonly observed with therapies that activate the glucagon-like peptide-1 receptor. Nausea occurred in 44% of pemvidutide patients and 24% of placebo recipients. Constipation was reported in 26% and 6%, diarrhoea in 20% and 10%, and vomiting in 18% and 6%, respectively.
Most adverse events were described as mild or moderate, but severe adverse events occurred in 12% of pemvidutide recipients compared with 6% of placebo recipients. Serious adverse events were reported in 4% and 2%, respectively. One case of hyponatremia in the pemvidutide arm was considered possibly related to treatment by the principal investigator.
Overall treatment discontinuation was similar between the groups, affecting 20% of pemvidutide patients and 22% receiving placebo. However, five pemvidutide recipients, representing 10% of the treatment arm, stopped because of drug-related adverse events, while no placebo recipients discontinued for that reason. The reported causes were two cases of vomiting and one case each of constipation, fatigue and worsening haemorrhoids.
These figures do not negate the efficacy signal, but they will influence dose selection and real-world acceptability. Alcohol use disorder often requires prolonged care, and a weekly injection associated with nausea, vomiting or constipation may be difficult for some patients to continue. The company used a simplified two-step dose escalation that it believes may improve tolerability compared with earlier pemvidutide regimens, but the claim will require confirmation in a larger trial.
The safety analysis included only 50 patients in each arm and covered 24 weeks. A registrational program will need to identify less common adverse events, examine longer exposure and evaluate use alongside psychiatric medicines, liver-disease treatments and therapies for other substance-use conditions.
Why pemvidutide could offer a different approach to alcohol use disorder treatment
Pemvidutide is an investigational peptide that activates glucagon and GLP-1 receptors in a balanced one-to-one ratio. GLP-1 receptor activity is associated with appetite regulation and may affect neurological pathways involved in reward and craving. Glucagon receptor activity is intended to produce direct effects in the liver, including reductions in liver fat, inflammation and fibrosis.
The combined mechanism could be relevant because alcohol use disorder frequently overlaps with obesity, excess liver fat and alcohol-associated liver damage. RECLAIM evaluated drinking behaviour rather than proving that treatment prevents cirrhosis or reverses alcohol-related liver injury. Altimmune is separately studying pemvidutide in the RESTORE Phase 2 trial for alcohol-associated liver disease.
Only three medications are currently approved by the FDA for alcohol use disorder: naltrexone, acamprosate and disulfiram. These medicines work through different mechanisms and can be combined with behavioural treatment, but medication use remains limited and no single option is appropriate for every patient.
Pemvidutide would introduce a weekly injectable metabolic therapy into a field dominated by older oral medicines and monthly injectable naltrexone. Its potential advantages include reducing heavy drinking while also producing weight loss and possibly addressing liver-related comorbidities. Its disadvantages may include gastrointestinal tolerability, injection burden, cost and uncertainty over how long therapy must continue to sustain the reduction in drinking.
The FDA has granted pemvidutide Fast Track designation for alcohol use disorder, but the designation does not represent approval or confirmation that the Phase 2 results will be reproduced. Altimmune plans to request an End-of-Phase 2 meeting to discuss registrational endpoints, study size, patient selection and the design of the next clinical trial.
The upcoming regulatory discussion will be particularly important because RECLAIM met two endpoints that the FDA recognizes for registration: a two-level reduction in World Health Organization risk drinking and no heavy drinking days. The agency must still decide how those measures should be incorporated into a pivotal program and whether additional evidence involving abstinence, durability, liver outcomes or broader patient groups will be required.
RECLAIM provides credible early evidence that pemvidutide may reduce harmful alcohol consumption beyond the effect observed with placebo. The result is strengthened by consistent secondary endpoints and an objective blood biomarker, but the small study, selected overweight population and treatment-related gastrointestinal discontinuations remain important limitations.
A larger trial must now show that the effect is durable, clinically useful across a more representative alcohol use disorder population and acceptable enough for patients to remain on treatment. Until those questions are answered, pemvidutide should be viewed as a promising investigational therapy rather than an established alternative to currently approved medications.
