A new Ozempic rival helps patients lose fat, but keep their muscle — the holy grail for a weight-loss drug

The headline result is promising, but it is still early evidence. A phase II trial can suggest a biologically interesting direction, yet it does not establish how well the drug performs in routine care, in different age groups, or over longer periods. For weight-loss medicines, the key question is not only how much weight changes, but whether people can sustain muscle, function and overall health as the body composition shifts.

That distinction matters because muscle loss is not a minor side effect for everyone. In people who are older, frail, or already undernourished, losing lean mass can affect strength, mobility and resilience. Even if the ratio of fat loss improves, the real-world impact depends on baseline fitness, protein intake, illness burden and activity levels. A treatment that looks superior on body-composition scans may still need careful monitoring to confirm it preserves day-to-day capacity.

The proposed exercise-like mechanism is plausible, but not yet a substitute for exercise. Drug-induced changes in appetite and metabolism can overlap with some effects of training, yet they are unlikely to reproduce the broader benefits of resistance work, such as neuromuscular adaptation, balance and bone loading. The most practical reading is that future obesity care may become more personalized, with medication and strength training complementing each other rather than competing.

For readers, the takeaway is to look beyond the scale. The best weight-loss strategy is increasingly being judged by composition, durability and safety, not just pounds lost. That is a useful shift — but it also raises the bar for evidence, because a therapy that preserves muscle in a trial still has to prove it helps people stay healthier in everyday life.

  • A new GLP-1 drug, pemvidutide, helped patients lose fat while guarding muscle like exercise does.
  • The weekly injectable from Altimmune saw trial participants lose about 75% fat and 25% muscle.
  • Eli Lilly and Novo Nordisk are also researching how to preserve muscle mass in GLP-1 users.
It’s the holy grail for a weight-loss drug: Stay strong, but lose the fat. The drugmaker Altimmune says its new weekly injectable, pemvidutide, saw patients lose about 75% fat and only 25% muscle in results of a Phase II clinical trial the company announced on Wednesday. That’s impressive when you compare it to existing GLP-1 drugs such as Ozempic and Wegovy, which use semaglutide, or Mounjaro and Zepbound, which use tirzepatide.

On those drugs, patients can lose as much as 40% of their muscle mass. Their muscle-to-fat ratio usually still improves, but in particularly vulnerable populations, such as older adults, rapid and significant muscle loss can be a dangerous issue. This is why doctors recommend patients on weight-loss drugs do some strength training in tandem with taking their medication.
But representatives for Altimmune say its drug may mimic the beneficial effects of weightlifting without making you do the work. Pemvidutide, like tirzepatide, is a two-part drug that combines a GLP-1 drug with another in a single shot. In this case, it’s boosting glucagon, a key blood-sugar-regulating hormone. While the GLP-1 reduces a person’s appetite, the glucagon is thought to mimic the effects of exercise, the company says. “There is a growing appreciation that the quality of weight loss is as important as the quantity of weight loss,” Scott Harris, Altimmune’s chief medical officer, said in a release. “We believe that pemvidutide, if approved, could stand out as an attractive option for weight loss and weight maintenance.”

Other drugmakers are trying to solve the issue of patients losing muscle while on drugs like Ozempic

In July, Eli Lilly, which makes Zepbound and Mounjaro, acquired Versanis, a privately held, clinical-stage biopharmaceutical company. The deal was worth $1.9 billion, FierceBiotech reported. Versanis makes a monoclonal antibody called bimagrumab, which is thought to help preserve more muscle mass, even through weight loss.
The same antibody is also being tried with semaglutide in a worldwide Phase II clinical trial run by Eli Lilly.
https://www.businessinsider.com/new-weight-loss-drug-mimics-exercise-with-a-shot-2024-3

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