Lilly's next-gen drug tops Zepbound on weight loss in late-stage trial

Eli Lilly said on Thursday its next-generation obesity drug helped patients lose an average of 28.7 percent of their weight in a late-stage trial, outperforming its blockbuster drug Zepbound and reinforcing the company's lead in the fast-growing market.

The global obesity market has surged in recent years on strong demand for GLP-1-based drugs like Zepbound and Novo Nordisk's Wegovy, prompting drugmakers to invest heavily in next-generation treatments that could deliver faster, deeper, or more durable weight loss.

Shares of Lilly, which last month became the first drugmaker to hit the $1 trillion valuation on surging demand for its weight-loss drugs, rose 1.4 percent in premarket trading. Rival Novo's US-listed shares slipped briefly on Lilly's announcement before bouncing back.

The once-weekly injected drug, retatrutide, is part of a class known as incretins designed to mimic the action of the GLP-1 hormone, which helps regulate blood sugar, slow stomach emptying and decrease appetite.

Lilly, in its first late-stage trial readout, said the highest dose of the drug delivered weight loss of up to an average of 71.2 pounds at 68 weeks, along with substantial relief from deep-aching joint pain when tested in participants with obesity and osteoarthritis of the knee.

"Today's results put a new high bar in weight-loss solutions," said Kevin Gade, chief operating officer at Lilly shareholder Bahl and Gaynor.

"For Lilly, this is likely another blockbuster drug with a long patent duration and adds to a full suite of solutions that physicians can tailor to individual patient needs," he said.

Lilly said on Thursday seven additional late-stage trials evaluating the drug in obesity and type 2 diabetes are expected to be completed in 2026.

TRIPLE "G" BOOSTS WEIGHT LOSS

Side effects were in line with those typically seen in weight-loss treatment trials, the company said, noting that dysaesthesia, an abnormal skin sensation, occurred in 20.9 percent of patients on the highest dose.

BMO Capital Markets analyst Evan Seigerman said dysaesthesia rates were "elevated" and that he would look to full data to be presented to better assess the severity of these events.

Overall 18.2 percent of patients treated with the 12-milligramme highest dose discontinued due to adverse events, compared to 4 percent on placebo. The company said some discontinuations were due to perceived excessive weight loss.

Unlike GLP-1 agonists such as tirzepatide, the active ingredient in Lilly's Mounjaro and Zepbound, and semaglutide, the active ingredient in Wegovy and Ozempic from Novo, retatrutide activates three hormone receptors - GLP-1, GIP and glucagon - earning it the nickname "triple G".

Rival Novo is also developing its own "triple-G" weight-loss drug candidate UBT251 after securing global rights for the treatment from China-based United Laboratories International in a licencing deal.

Triple-G weight loss drugs are expected to produce greater weight loss than previous generations by combining appetite suppression, blood sugar control and increased calorie burning.

There have been significant investor expectations around retatrutide after mid-stage data demonstrated up to 24.2 percent weight loss after 48 weeks, surpassing results seen with other obesity drugs.