Pfizer Discontinues Oral GLP-1 Asset Danuglipron, Deals Blow to Obesity Drug Pipeline

Pharmaceutical giant Pfizer has announced the discontinuation of its oral GLP-1 receptor agonist, danuglipron, following a potential case of drug-induced liver injury in a phase 1 trial. This decision marks a significant setback for the company's ambitions in the highly competitive obesity drug market.

Liver Safety Concerns Prompt Discontinuation

Pfizer's decision to axe danuglipron came after a comprehensive review of clinical data and consultations with regulatory authorities. The company reported that one patient in a phase 1 trial experienced potential drug-induced liver injury, which resolved after discontinuation of the treatment. While Pfizer noted that the overall frequency of liver enzyme elevations across more than 1,400 patients in the safety database was consistent with approved agents in the GLP-1 class, the isolated case proved to be a decisive factor in the drug's fate.

Chris Boshoff, M.D., Ph.D., Pfizer's Chief Scientific Officer, had previously highlighted the potential of danuglipron, even suggesting its possible combination with a GIPR antagonist currently in phase 2 development. However, this latest development has effectively eliminated the prospect of such a combination therapy for the near future.

Impact on Pfizer's Obesity Strategy

The discontinuation of danuglipron represents a significant blow to Pfizer's strategy in the obesity treatment landscape. This setback follows the company's earlier decision to scrap another oral GLP-1 candidate, lotiglipron, in 2023 due to elevated liver enzymes observed in clinical trials. Pfizer had subsequently pivoted its focus to a once-daily formulation of danuglipron, which was seen as a potential competitor to rival treatments from companies such as AstraZeneca, Eli Lilly, Novo Nordisk, Structure Therapeutics, and Viking Therapeutics.

With the loss of its lead candidate in the oral GLP-1 space, Pfizer now faces the challenge of recalibrating its approach to the obesity market. The news has already had ripple effects in the industry, with shares of Structure Therapeutics and Viking Therapeutics seeing significant increases in premarket trading, rising 10% and 13% respectively.

Competitive Landscape and Future Outlook

The discontinuation of danuglipron raises questions about Pfizer's next moves in the obesity drug race. While the company still has an oral small molecule GIPR antagonist in phase 2 development for adults with obesity, the loss of danuglipron leaves a considerable gap in its pipeline.

As Pfizer reassesses its strategy, competitors in the oral GLP-1 space may find themselves in a strengthened position, provided they can navigate the safety concerns that have plagued Pfizer's candidates. The development also underscores the challenges and risks inherent in bringing novel obesity treatments to market, particularly in a field where safety profiles are scrutinized closely by regulators and physicians alike.