Pfizer Halts Development of Weight-Loss Pill After Liver Injury in Trial

The pharmaceutical giant discontinues danuglipron following safety concerns but shifts focus to alternative obesity treatments in its pipeline.

Pfizer has ended the development of its experimental once-daily weight-loss pill, danuglipron, after a trial participant experienced a potential drug-induced liver injury.
The liver injury, which resolved after the medication was stopped, prompted Pfizer to review clinical data and regulatory feedback before making the decision to discontinue the program.
This marks the second setback for danuglipron, following the abandonment of its twice-daily formulation in late 2023 due to significant tolerability issues, including high dropout rates from side effects.
Despite the discontinuation, Pfizer reported that the overall frequency of liver enzyme elevations in danuglipron trials was comparable to those seen with approved GLP-1 drugs.
Pfizer is redirecting its efforts toward other investigational obesity therapies, including an oral drug targeting the GIP receptor, which is currently in phase 2 trials.