Altimmune updates Phase 2 body composition results for pemvidutide
Altimmune, Inc. (Nasdaq:ALT), a clinical-stage biopharmaceutical company, has issued corrected results from its Phase 2 MRI-based body composition sub-study of pemvidutide, its investigational therapy for weight management. The revised analysis was presented at the Annual Meeting of the European Association for the Study of Diabetes and highlighted clearer patterns of fat loss and metabolic change. In short, the update refines how much fat was lost and where it was lost—details that matter for health risk and for how patients may feel as they lose weight.
While the topline message remains the same—pemvidutide reduced body fat with modest impact on lean mass—the corrections sharpen that picture. The data now point to a larger drop in visceral fat and a slightly smaller reduction in subcutaneous fat than first reported, with lean mass preservation remaining a key feature.
Visceral vs. subcutaneous fat: what changed
Two fat depots are in focus: visceral adipose tissue (VAT), which collects around internal organs and is tied more closely to cardiometabolic risk, and subcutaneous adipose tissue (SAT), which sits beneath the skin. In the corrected readout, VAT fell by 28.3% at Week 48, up from the initially reported 25.6%. That upward revision strengthens the conclusion that pemvidutide preferentially reduces the more harmful visceral fat. SAT decreased by 19.5%, a touch below the earlier 20.1% estimate, indicating a still substantial but comparatively smaller change.
Why does the split matter? Because where fat is lost can influence downstream risk. Larger reductions in VAT are generally linked with improvements in markers tied to cardiovascular health and metabolism. The new figures suggest pemvidutide is doing more work in that higher-risk compartment while still trimming subcutaneous fat at a meaningful rate.
What the data mean for older adults
Scott Harris, M.D., Chief Medical Officer at Altimmune, underscored the relevance of these findings for people over 60, a group more vulnerable to frailty and its complications. The study reported a lean loss ratio of 21.9%, indicating that the majority of weight lost was fat rather than lean tissue. Among older adults specifically, that ratio improved to 19.9%, pointing to even better preservation of lean mass in this population.
This matters in daily life. Maintaining lean mass can support strength, balance, and mobility, potentially lowering the risk of falls and injuries. It can also help preserve function through day-to-day activities—walking a flight of stairs, carrying groceries, getting up from a chair—while still delivering the intended benefits of weight reduction. Said differently: losing the weight you want to lose, and keeping the muscle you need.
How pemvidutide works
Pemvidutide is designed as a dual receptor agonist of GLP-1 and glucagon. That dual action aims to mirror the combined effects of eating less and burning more: it helps suppress appetite while increasing energy expenditure. In clinical observation, treatment with pemvidutide has been associated with weight loss alongside improvements in triglycerides, LDL cholesterol, liver fat, and blood pressure—factors that often move in the right direction when metabolic health improves.
Reflecting its potential in liver and metabolic disease, the U.S. Food and Drug Administration has granted pemvidutide Fast Track designation for applications related to metabolic dysfunction-related liver conditions. While Fast Track isn’t an approval, it can support more frequent interactions with the FDA and a potentially more efficient review process.
Ongoing studies and what’s next
Altimmune continues to advance its clinical program following positive results in studies such as MOMENTUM. The company is currently running the IMPACT Phase 2b trial to further evaluate pemvidutide in metabolic dysfunction-associated steatohepatitis (MASH). The aim is to build a fuller evidence base across obesity and related metabolic conditions, where both fat distribution and lean mass preservation matter for long-term outcomes.
As these trials progress, the focus remains practical: demonstrate consistent weight reduction, favor visceral fat loss, and preserve lean tissue—particularly in older adults—while tracking cardiometabolic measures that shape everyday health.
About Altimmune
Altimmune develops next-generation peptide-based therapeutics aimed at chronic conditions such as obesity and its complications. By tying rigorous clinical research to real-world needs, the company seeks to improve patient care and outcomes. Pemvidutide sits at the center of that effort, with body composition data that now paint a clearer, more nuanced picture of its potential.
Frequently Asked Questions
What changed in Altimmune’s corrected analysis?
The revision raised the reduction in visceral adipose tissue to 28.3% at Week 48 (from 25.6%) and slightly lowered the subcutaneous adipose tissue reduction to 19.5% (from 20.1%). The overall takeaway—greater loss of visceral fat with preservation of lean mass—remains intact.
Why is visceral fat loss emphasized over subcutaneous fat loss?
Visceral fat sits around internal organs and is more closely tied to cardiometabolic risk. A larger drop in visceral fat suggests greater potential benefit for cardiovascular and metabolic health compared with the same amount of subcutaneous fat loss.
What does a “lean loss ratio of 21.9%” mean?
It’s the proportion of total weight lost that came from lean tissue rather than fat. A 21.9% ratio indicates most of the weight loss was fat. In adults over 60, the ratio was even lower at 19.9%, suggesting better lean mass preservation.
How does pemvidutide work in the body?
Pemvidutide activates GLP-1 and glucagon receptors. This dual action helps reduce appetite and increase energy expenditure, and has been associated with improvements in triglycerides, LDL cholesterol, liver fat, and blood pressure in clinical observation.
What studies are underway for pemvidutide?
Altimmune is conducting the IMPACT Phase 2b trial to further assess pemvidutide in metabolic dysfunction-associated steatohepatitis (MASH), building on prior work that includes the MOMENTUM study.
