Pfizer just had a big setback in its race for an Ozempic competitor

The patient, who was asymptomatic, recovered after they stopped taking the medication, according to a statement from the U.S.-based pharmaceutical giant.

While the statement didn’t directly say the participant’s liver enzymes were elevated, it pointed out that “the overall frequency of liver enzyme elevations across the over 1,400 participant safety database of danuglipron is in-line with approved agents in the class.” This can often indicate damage to liver cells, an issue that has been linked to other weight-loss drugs, according to CNBC.

“While we are disappointed to discontinue the development of danuglipron, we remain committed to evaluating and advancing promising programs in an effort to bring innovative new medicines to patients,” Pfizer chief scientific officer Dr. Chris Boshoff said in the release, adding that the company will continue developing other weight-loss drugs. Pfizer said that data from the trial will still be submitted to the scientific community for further study.

Pfizer was developing danuglipron, an oral GLP-1 drug, as something of a rival to Ozempic and Wegovy, both of which are manufactured by Denmark-based Novo Nordisk (NVO). Early trials had shown that Pfizer’s pill resulted in about as much weight loss as Wegovy.

An oral weight-loss medication would be far less invasive than the injections required by most GLP-1s. Like Pfizer, pharma giants including Novo Nordisk, Eli Lilly $LLY (LLY), and AstraZeneca $AZN (AZN) are working on their own oral weight-loss pills. Viking Therapeutics (VKTX), a San Diego-based pharma company, has also shown promising results in early trials.

Despite the setback, Pfizer’s stock was up 0.9% Monday morning. Eli Lilly rose 1.6%, and Novo Nordisk rose 2.5%.