Pfizer Inc.’s stock PFE fell 4% premarket on Friday, following the company’s announcement that it will not proceed with a Phase 3 trial of its twice-daily formulation of an oral GLP-1 candidate in adults with obesity and type 2 diabetes. This decision came after the Phase 2b trial reported high rates of adverse events.
Positive outcomes in the Phase 2b trial
Despite the discontinuation of the Phase 3 trial, Pfizer stated that the Phase 2b trial achieved its primary endpoint by demonstrating a statistically significant change in body weight compared to placebo. The twice-daily dosages of danuglipron showcased promising results, with placebo-adjusted weight reductions ranging from 8% to 13% at 32 weeks and 5% to 9.5% at 26 weeks.
High rates of adverse events
However, the company noted that the most common adverse events observed were mild and gastrointestinal in nature, consistent with the drug’s mechanism of action. These adverse events included nausea (up to 73% incidence), vomiting (up to 47% incidence), and diarrhea (up to 25% incidence). Additionally, the trial experienced high discontinuation rates, exceeding 50%, across all dosage groups compared to approximately 40% with placebo.
Focus on once-daily formulation
Although Pfizer has decided not to pursue the twice-daily formulation further, the company believes that a once-daily formulation could still play a significant role in obesity treatment. Dr. Mikael Dolsten, Pfizer’s chief scientific officer and president of Pfizer R&D, stated, “Results from ongoing and future studies of the once-daily danuglipron modified release formulation will inform a potential path forward with an aim to improve the tolerability profile and optimize both study design and execution.”
Stock performance
Pfizer’s stock has experienced a 40.5% decline year-to-date, contrasting with the S&P 500’s gain of 19%.
