Pfizer Ends Development of Weight-Loss Pill Danuglipron After Safety Concerns

Pfizer has officially discontinued development of its experimental weight-loss pill, danuglipron, after a trial participant experienced a potential drug-induced liver injury, Deena Beasley reported for Reuters.

Despite dose-optimization studies showing liver enzyme elevations in line with other approved GLP-1 drugs, Pfizer said one patient developed a case of liver injury. I Photo: Pfizer

The company said the liver issue resolved after the patient stopped taking the drug. Pfizer had been testing a once-daily version of danuglipron, after scrapping a twice-daily formulation in late 2023 due to high dropout rates linked to side effects, including nausea and vomiting.

Danuglipron was seen as a potential oral alternative in the booming weight-loss drug market, currently dominated by weekly injectables such as Novo Nordisk’s Wegovy and Eli Lilly’s Zepbound.

Analysts expect the global weight-loss drug market to hit $150 billion in annual sales in the coming years.

Despite dose-optimization studies showing liver enzyme elevations in line with other approved GLP-1 drugs, Pfizer said one patient developed a case of liver injury that prompted the decision.

“After a review of the totality of information, including all clinical data and recent input from regulators,” the company said, it has opted to cease further development of danuglipron.

BMO Capital Markets analyst Evan Seigerman said the decision puts Pfizer “back to square one” in the obesity space, with its remaining candidates still in early stages of development.

He added the company may now explore partnerships or acquisitions to stay in the race.

Pfizer said it will continue working on other experimental obesity drugs, including one targeting the hormone GIPR, and plans to present data from the danuglipron program at a future scientific conference or in a peer-reviewed journal.