On Friday, Pfizer announced the discontinuation of the development of the twice-daily variant of its experimental weight loss pill. This decision follows a mid-stage clinical study where obese patients experienced substantial weight loss while facing challenges in tolerating the drug. The pharmaceutical company noted elevated rates of adverse side effects, primarily mild and gastrointestinal in nature, among the participants. Additionally, a noteworthy percentage of patients opted to discontinue the use of the drug.
The company stated that, currently, the twice-daily danuglipron formulation will not progress into Phase 3 studies. However, Pfizer indicated its intention to unveil phase two trial data for a once-a-day version of the drug in the first half of 2024, aiming to gain insights that will guide future decisions. The pharmaceutical giant will assess this data before determining whether to initiate a phase three study on the once-daily pill, perceived by Wall Street as the more competitive form of the treatment.
Pfizer witnessed a 4% decline in premarket trading on Friday following the disclosure of trial results. The setback in the data pertaining to the twice-daily drug poses a challenge to Pfizer’s aspirations of securing a $10 billion share in the flourishing weight loss drug market, as CEO Albert Bourla previously anticipated it could expand to $90 billion. The company is relying on the success of a weight loss pill to counteract the decline in demand for its Covid products and the approximately 40% drop in its share price this year.
Investor sentiment towards Pfizer’s prospects in the weight loss drug sector has been negative, particularly since the company abandoned a different once-daily pill in June in favor of the less appealing danuglipron. With the data released on Friday, Pfizer finds itself trailing even more significantly behind the leading players in the weight loss drug market, namely Eli Lilly and Novo Nordisk. These industry giants are actively pursuing the development of more user-friendly pill versions of their highly successful weight loss and diabetes injections, intensifying the competition.
Pfizer conducted a phase two trial involving approximately 600 obese adults without Type 2 diabetes, investigating its twice-daily pill. The trial assessed the drug’s impact on weight loss over periods of 26 or 32 weeks, employing varied dosage levels spanning from 40 milligrams to 200 milligrams. Similar to Novo Nordisk’s Wegovy and Ozempic, Pfizer’s pill operates by emulating a gut-produced hormone called GLP-1. This hormone signals to the brain, indicating a sense of fullness in individuals.
Pfizer reported that the danuglipron trial successfully achieved its primary objective by demonstrating “statistically significant” reductions in body weight. Individuals who consumed the pill twice daily experienced an average weight loss ranging from 6.9% to 11.7% at 32 weeks and from 4.8% to 9.4% at 26 weeks. In contrast, participants on a placebo exhibited weight gains of 1.4% at 32 weeks and 0.17% at 26 weeks.
When accounting for the variance in weight gain observed in patients who were administered the placebo, Pfizer’s twice-daily pill resulted in an average weight loss of 8% to 13% at 32 weeks and 5% to 9.5% at 26 weeks. The company noted elevated rates of adverse events in the study, with up to 73% experiencing nausea, up to 47% reporting vomiting, and up to 25% encountering diarrhea. Moreover, more than 50% of patients across all dosage levels discontinued the pill, in contrast to roughly 40% among those on the placebo, as reported by Pfizer.
No additional safety concerns emerged, and danuglipron did not show an association with elevated liver enzymes, a contrast to Pfizer’s previously discontinued weight loss pill. Information from the phase two trial will be shared at an upcoming scientific conference or published in a peer-reviewed journal.