Pfizer Inc.’s has opted to discontinue development of its experimental obesity drug danuglipron. This comes after the FDA reported a serious liver injury in one patient from the clinical development program. This oral medication, designed to promote weight loss by targeting GLP-1 (glucagon-like peptide-1), was undergoing late-stage testing to assess its efficacy and tolerability.
Researchers were testing Danuglipron in several doses to determine whether it could work as a once-daily pill. Pioneering research indicated danuglipron’s strong focus as a GLP-1 agonist. This hormone is a key regulator of appetite and blood sugar. This mechanism is like that of other popular GLP-1s, including Novo Nordisk’s Wegovy and Ozempic.
As that reporting suggests, during the trials Pfizer was announcing groundbreaking news every week. The rate of elevated liver enzymes in patients taking danuglipron mimicked what we’ve seen with approved GLP-1s. The safety database for danuglipron comprised more than 1,400 patients who had actively enrolled in the trials. Worries set in when a second patient developed a serious liver injury that may have been caused by the drug. Fortunately, the patient’s liver enzymes “returned to baseline within a few days” after stopping the drug.
During the second half of 2023, Pfizer initiated trials of danuglipron. They wanted to create a safer and more effective oral alternative for treating obesity. Yet the love affair came crashing down when this liver injury was discovered and led to the pharmaceutical company completely reevaluating its direction. As of December 2023, Pfizer had already stopped development on a twice-daily version of danuglipron due to patient tolerability concerns.
The decision to discontinue danuglipron’s development highlights the challenges faced by pharmaceutical companies in bringing new obesity treatments to market. As pointed out by Mikael Dolsten, Pfizer’s former Chief Scientific Officer, “there are a thousand applications for GLP-1s.” GLP-1 agonists hold tremendous potential to help people manage their weight and diabetes. This demand is echoed by the rising interest in these fields as creative and technological melting pots for new innovative solutions.
Though this may be a blow for Pfizer, there are still multiple other experimental obesity drugs that it is pursuing in its pipeline. Despite the danuglipron stop, the company remains committed to fighting obesity. What they do get is that this is a key public health frontier making big waves across the globe.