Eli Lilly & Co.’s experimental weight loss pill helped patients shed pounds without serious side effects in a clinical trial, burnishing the drug’s blockbuster potential in the company’s competition with Novo Nordisk A/S.

The highest dose helped patients with Type 2 diabetes lose 7.6% of their body weight, during the 40-week study, according to data presented Saturday at the American Diabetes Association conference in Chicago. The results, published in the New England Journal of Medicine, found no signs of liver damage in patients on the drug, easing concerns that Lilly’s medicine might run into side effects that derailed earlier attempts to develop potent weight-loss pills.

The study details affirm the drug’s promise after Lilly shared a promising first look at the data in April. The company expects to launch the pill, called orforglipron, next year.

The lack of serious side effects answers the most important outstanding question about Lilly’s pill, said Daniel Drucker, an endocrinologist and obesity researcher at the University of Toronto, who was not involved in the study. Overall, the trial was “not a home run, but very respectable,” Drucker said.

Shots from Lilly and rival Novo have revolutionized the way obesity is treated. But drugs like orforglipron that can be taken orally, rather than injected, are key to reaching more patients and dominating the market. Pfizer Inc. and AstraZeneca Plc are among a handful of companies now racing to develop their own pills, although the science has proven to be a challenge.

Drugmakers are vying for a place in the market for novel weight loss medicines, projected to reach as much as $150 billion a year within a decade. Access to the medicines has so far been limited by insurers’ reluctance to cover their price tags, which can top $1,000 a month. But analysts expect adoption to increase as the drugs’ long-term benefits come into view.

On Friday, the American College of Cardiology updated its treatment guidelines to recommend that weight loss drugs be given earlier to people at risk for heart disease, a move that could widen insurance coverage.

Lilly is testing orforglipron in diabetes, obesity and related conditions like sleep apnea. Results from its main obesity trial won’t be revealed until later this year.

Lilly’s April early look at orforglipron showed how the pill fared in diabetics. Patients in the study shed more weight than those in earlier trials of Novo’s bestselling Ozempic shot. Those in the Lilly trial hadn’t hit a weight plateau when the study ended, suggesting they may lose even more, the company said in a statement at the time. Blood sugar levels fell by an average of 1.3%, slightly underperforming Novo’s rival pill.

The most common side effect in Lilly’s study was diarrhea, affecting about 25% of patients on the highest dose. Patients also reported indigestion, vomiting and nausea at rates comparable to injectable medicines. About 8% of patients on the highest dose left the study due to side effects.

Novo already sells a pill for diabetes called Rybelsus. Until recently, supply issues had put development of a higher-dose version of the pill for obesity on hold. In early May, Novo said the U.S. Food and Drug Administration had accepted its filing submission, with a decision expected later this year.

Lilly plans to file for FDA approval of orforglipron in obesity later this year and has already stockpiled roughly $600 million worth of the medicine ahead of a potential launch, according to financial filings.

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(With assistance from Damian Garde.)

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