Regeneron boss says weight-loss drugs could 'do more harm than good'

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Regeneron's co-founder has warned that blockbuster weight-loss drugs could do “more harm than good” if the rapid muscle loss associated with the treatments is not addressed, as the US biotech company presses ahead with trials of muscle-preserving drugs.

Clinical trials suggest that patients treated with the new class of weight-loss drugs called GLP-1 lose muscle far more quickly than people who lose weight through diet or exercise, exposing them to health problems, George said Yancopoulos, who also serves as Regeneron's chief scientific officer.

According to a 2024 JAMA study, this means that for two in five patients who stop treatments within a year, they are likely to return to their original weight with less muscle and a higher percentage of body fat, “adding insult to injury.” said Yancopoulos.

“I think the GLPs should be viewed with great concern in terms of how they are actually used in the real world,” Yancopoulos said. “They could lead to gradual changes in body composition that could do more harm than good in the long run.”

Regeneron is among a growing list of drugmakers researching experimental drugs to preserve lean muscle mass in combination with GLP-1 drugs, seeking a path into a potentially $130 billion-a-year market driven by the Ozempic and Wegovy manufacturers Novo Nordisk and Eli Lilly. the company behind Mounjaro and Zepbound.

Regeneron, a $111 billion biotech company that specializes in antibody treatments, is testing in mid-stage trials a drug called trevogrumab, which blocks the hormone myostatin, which limits muscle growth, in combination with Wegovy. According to industry researcher Citeline, there are 11 myostatin drugs in biotech pipelines, seven of which are currently being studied for obesity.

Last year, Eli Lilly bought Boston-based biotech Versanis in a $1.9 billion deal to get its hands on its muscle-preserving treatment to complement its weight-loss drugs. BioAge, a biotech company with a muscle recovery drug that works with Eli Lilly, listed on the stock market last month and its stock price has risen 21 percent.

Clinical data shows that 25 percent of the weight loss from Eli Lilly's vaccination was due to a reduction in lean body mass, including muscle, while 40 percent of the Novo Nordisk vaccination was due to a decrease in lean body mass.

The U.S. Food and Drug Administration recommends taking the medication in combination with diet and exercise. Novo Nordisk said clinical data “[does] “do not indicate an association between greater loss of lean body mass versus greater loss of fat mass with semaglutide treatment.” Eli Lilly did not immediately respond to a request for comment.

The first clinical data from Regeneron's Phase 2 trial of trevogrumab is expected by the middle of next year. Regeneron is also considering moving a monthly GLP-1 injection into clinical trials, which the company has tested in mice. Despite his concerns about the drug, Yancopoulos said Regeneron was “thinking about becoming a player in the GLPs.”

“I'm not sure that the GLPs are really the final answer here because they could pose significant long-term problems,” he added.

“We all want to have 10 pounds more muscle and 10 pounds less fat, but we could eat whatever we want – that's the ideal world,” Yancopoulos said.

“We don’t all want to suffer from nausea and nausea and lose muscle. I think so. . . An ideal future is one in which we can combat metabolic diseases in a better and healthier way.”