Pfizer Halts Development of Danuglipron Due to Liver Concerns

Multiple pharmaceutical companies are currently exploring oral medications for obesity, which could offer a more straightforward alternative to injectable treatments that utilize incretin mimetics. Pfizer, however, has recently announced a setback in its research efforts by discontinuing the development of Danuglipron. This low-molecular-weight compound had undergone evaluation in two Phase I studies aimed at determining optimal dosing for individuals suffering from obesity or Type 2 diabetes.

In late 2023, Pfizer had already abandoned a twice-daily dosage regimen due to a significant number of participants withdrawing from the trials because of adverse effects such as nausea and vomiting. The company then shifted its focus to a once-daily formulation for further investigation.

According to Pfizer, while the overall incidence of liver enzyme elevations in the safety database of Danuglipron, which included over 1,400 participants, aligned with that of approved drugs in this category, a single asymptomatic participant in one of the dose-optimization studies experienced a potential drug-induced liver injury. This condition resolved after discontinuing the drug. Following a careful assessment and consultations with regulatory authorities, Pfizer has opted not to pursue further clinical development for Danuglipron.

Despite this setback, Pfizer remains committed to researching obesity treatments. The company has another candidate, PF-07976016, in its pipeline, which is also aimed at combating obesity. This orally available compound targets gastric inhibitory polypeptide (GIP) and is currently in Phase II trials. To date, only one incretin mimetic, Semaglutide, has received approval in oral form (Rybelsus®), yet it is exclusively indicated for individuals with Type 2 diabetes and is not available in the German market.

The announcement from Pfizer had immediate repercussions on the stock market, as reported by Handelsblatt, with positive impacts noted for competitors Novo Nordisk and Eli Lilly, who have been leading the obesity treatment market.