Pfizer halts development of promising oral obesity medication following safety concerns
Pfizer has announced the discontinuation of its once-daily oral obesity treatment, danuglipron, ahead of its transition to the most advanced and costly phase of clinical trials. The decision marks a significant shift in the pharmaceutical giant’s approach to tackling obesity, a therapeutic area that has rapidly gained prominence and commercial value.
The company revealed on Tuesday that it would cease development of the once-daily formulation of danuglipron after a participant in a clinical study experienced a potential drug-induced liver injury. The adverse effect resolved once the individual stopped taking the medication.
A Pfizer spokesperson explained that the once-daily pill was undergoing early-stage testing focused on determining the optimal dosage for people living with obesity. The original plan had been to progress into late-stage clinical trials, which typically serve as the final step before regulatory approval is sought.
Although this version of danuglipron will no longer be pursued, a company representative confirmed: “Pfizer still plans to develop other potential obesity treatments in earlier stages of testing.”
Obesity therapeutics have become one of the most dynamic and financially rewarding segments of pharmaceutical development. In 2024, Eli Lilly’s Zepbound, an injectable medication for obesity, generated close to $5 billion in its first full year on the market. Similarly, Novo Nordisk’s Wegovy has seen substantial commercial success. However, both of these leading therapies require injection, a delivery method that can be a barrier for some individuals.
As a result, there is growing industry interest in developing oral alternatives that offer greater convenience and are likely to be more acceptable to people reluctant to self-inject or attend frequent medical appointments. Eli Lilly is expected to release results later this year from clinical trials investigating several oral obesity treatments currently in development.
Despite the success of these medications, accessibility remains a major challenge. Many people face barriers to treatment due to recent supply shortages or inconsistent insurance coverage. Although both Lilly and Novo Nordisk have recently announced price reductions, the monthly cost of these treatments still runs into the hundreds of dollars, making them unaffordable for many individuals without adequate coverage.
Pfizer’s decision to halt development of the once-daily danuglipron follows an earlier move in late 2023, when the company discontinued its twice-daily formulation of the same drug. That version had advanced to mid-stage testing but was abandoned after more than half the participants in a clinical trial discontinued use.
As part of its latest announcement, a Pfizer spokesperson also confirmed that the company will no longer pursue trials of danuglipron in combination with other medications for obesity treatment.
While the company recalibrates its strategy in the obesity space, the market response remained muted. On Monday morning, shares of New York-based Pfizer Inc. rose by 12 cents to $22.03.
Pfizer’s withdrawal from the danuglipron programme underscores the complexity of developing safe and effective oral medications for obesity. The company’s ongoing commitment to researching new treatments may yet yield novel therapeutic options in a field of growing urgency and unmet need.
