Pfizer Halts Development of Obesity Drug Danuglipron Over Liver Safety Concerns.

Pfizer has announced it will cease development of danuglipron, its leading oral GLP-1 receptor agonist for obesity, after identifying a potential case of drug-induced liver injury during ongoing clinical trials. The decision significantly reduces the company’s obesity drug pipeline, leaving only one clinical-stage candidate in progress.

The pharmaceutical giant disclosed that the liver complication was observed during dose-optimization studies. Although the affected patient remained asymptomatic and the issue resolved after stopping the treatment, Pfizer opted to discontinue danuglipron following a comprehensive review of clinical data and regulatory feedback.

“While danuglipron is not our only asset in the obesity space, this update places us back at the starting line,” BMO Capital Markets commented in a note on Monday.

To date, more than 1,400 patients have received danuglipron, and the overall incidence of elevated liver enzymes was reportedly consistent with other approved GLP-1 therapies. Nonetheless, Pfizer concluded that the risks outweighed the benefits of continuing development.

This marks the second GLP-1 obesity drug Pfizer has dropped in recent years. In June 2023, the company shelved lotiglipron due to similar liver safety concerns, specifically elevated transaminase levels.

Danuglipron had already faced significant challenges prior to this latest development. In December 2023, Pfizer scrapped its twice-daily dosing regimen after Phase IIb trials showed high side effect rates—73% of patients experienced nausea, 47% reported vomiting, and 25% had diarrhea. More than half of all participants discontinued treatment due to adverse effects.

In response, Pfizer reformulated danuglipron into a once-daily pill and resumed testing in July 2024, bringing it back to Phase I. Despite this adjustment, enthusiasm for the asset remained cautious. At the January 2025 J.P. Morgan Healthcare Conference, CEO Albert Bourla reaffirmed Pfizer’s commitment to obesity treatment but acknowledged the uncertainties surrounding danuglipron.

With this discontinuation, Pfizer’s sole remaining clinical-stage obesity candidate is PF-07976016, an oral GIP analog currently in Phase II development, with an estimated study completion in December 2025.

Meanwhile, analysts from William Blair suggested that the setback could present new opportunities for partnerships. They highlighted Viking Therapeutics’ VK2735 as a potential pathway for Pfizer to regain a foothold—and possibly a leadership position—in the increasingly competitive obesity treatment market, currently dominated by Novo Nordisk and Eli Lilly.

Source:https://www.biospace.com/drug-development/pfizer-drops-lead-obesity-asset-after-liver-safety-concerns-overall-review

This is non-financial/medical advice and made using AI so could be wrong.