Pfizer Halts Development of Obesity Pill After Patient Liver Concerns

The American pharmaceutical giant Pfizer has discontinued the development of its experimental weight-loss pill following safety concerns, marking a significant setback in its pursuit of the lucrative anti-obesity market, estimated to reach £100 billion by 2030.

The decision came after a trial participant developed liver complications potentially linked to the drug, danuglipron. The company had previously abandoned a twice-daily version of the medication in late 2023 due to widespread patient withdrawals caused by severe side effects, including nausea and vomiting.

This development occurs amid fierce competition in the weight-loss drug sector, with major pharmaceutical companies vying for market share. AstraZeneca, Britain’s largest pharmaceutical enterprise, and Swiss-based Roche are among the contenders. Roche recently secured a substantial £5.3 billion collaboration agreement with Danish biotechnology firm Zealand Pharma.

The current market leaders, Novo Nordisk and Eli Lilly, have established dominance through their respective products. Novo Nordisk markets semaglutide under the brands Ozempic for diabetes and Wegovy for obesity, while Eli Lilly offers tirzepatide as Mounjaro for diabetes and Zepbound for obesity.

Despite the setback, Pfizer’s shares remained stable in pre-market trading, while Eli Lilly saw a 1.8 per cent increase. Novo Nordisk experienced a notable 3.8 per cent rise in Copenhagen trading. The company maintains its commitment to obesity research, focusing on alternative drug candidates targeting different hormones.

The development halt represents a significant challenge for Pfizer, which has struggled to maintain momentum since its Covid-19 success. The company’s share value has declined by more than two-thirds since late 2021, prompting a comprehensive restructuring programme including substantial cost reductions and job losses across its global operations, including its UK facilities.