Pfizer's Obesity Program Faces Setback as Last GLP-1 Drug Discontinued

Pharmaceutical giant Pfizer has announced the discontinuation of its final GLP-1 agonist, PF-06954522, dealing another blow to the company's embattled obesity program. This decision, coupled with updates on other pipeline assets, marks a significant shift in Pfizer's strategy for addressing metabolic diseases and other key therapeutic areas.

GLP-1 Program Closure and Obesity Strategy Pivot

Pfizer confirmed to Fierce Biotech that it has halted development of PF-06954522, citing poor phase 1 data and the competitive landscape in the GLP-1 market. This move follows the earlier discontinuation of two other GLP-1 candidates, lotiglipron and danuglipron, due to liver-related concerns.

A Pfizer spokesperson emphasized that the decision to end PF-06954522's development "was not related to any safety concerns that arose in the phase 1 program." Instead, the company made the call "following a review of data from its phase 1 program and the GLP-1 landscape."

With the closure of its GLP-1 program, Pfizer's obesity strategy now centers on PF-07976016, a GIPR antagonist currently in phase 2 development. The company has indicated it will "continue to evaluate external opportunities to complement our internally discovered and developed molecules" in the obesity space.

C. Difficile Vaccine Development Progress

While Pfizer's obesity program faces challenges, the company reported positive developments in its Clostridium difficile vaccine efforts. Despite discontinuing PF-06425090, which failed to meet its primary endpoint in a phase 3 trial, Pfizer has developed a next-generation formulation with promising results.

The new vaccine candidate has shown a four-fold increase in functional toxin-neutralizing antibody titers compared to its predecessor in phase 2 trials. Notably, this updated version requires only two doses instead of three and incorporates an adjuvant to enhance immune response.

Pfizer plans to advance this next-generation C. difficile vaccine into phase 3 trials later this year, targeting a significant unmet need in the prevention of C. difficile infections, which affect approximately 500,000 people annually in the U.S.

Pipeline Updates and Future Focus

In addition to the changes in its obesity and vaccine programs, Pfizer disclosed the discontinuation of two phase 1 assets:

1. PF-07293893, an AMP-activated protein kinase activator for heart failure
2. PF-07820435, an oral STING agonist for solid tumors

Despite these setbacks, Pfizer remains committed to advancing treatments for cardiovascular and metabolic diseases, including obesity. The company's chief scientific officer, Chris Boshoff, M.D., Ph.D., emphasized Pfizer's ongoing efforts to "fill critical gaps in patient care" in these areas.

As Pfizer navigates these pipeline changes, the pharmaceutical industry will be watching closely to see how the company repositions itself in the competitive obesity market and advances its remaining pipeline assets.