Pfizer Inc. has disclosed clinical results and a development strategy for its investigational weight-loss injection, berobenatide, as it seeks to gain share in a market currently led by Eli Lilly and Novo Nordisk. The New York-based pharmaceutical company emphasized the potential competitive edge of a monthly dosing schedule while outlining plans to expand late-stage testing and manufacturing capacity.
The data and program details were presented at the American Diabetes Association conference in New Orleans, where Pfizer highlighted results inherited from last year’s $10 billion acquisition of Metsera Inc. Berobenatide is described as a long-acting GLP-1 receptor agonist peptide that Pfizer acquired with Metsera.
Chris Boshoff, Pfizer’s chief scientific officer, framed the development as a turning point, saying in an interview with Bloomberg, "We are entering a new era of internal medicine innovation." Pfizer reported results from two Phase 2 studies that it says support further development of the candidate.
In the Phase 2b VESPER-1 study, patients who escalated to the highest weekly dose registered a 15.9% reduction in body weight over eight months, with the company noting that this weight loss did not show a plateau during that period. Additional findings from the VESPER-3 trial, which evaluated overweight or obese participants without diabetes, indicated that subjects receiving the highest dose every four weeks lost nearly 15% of body weight after 14 months.
Pfizer highlighted the potential convenience of a monthly dosing regimen, presenting berobenatide as a candidate to become the first-in-class therapy administered once a month - a contrast it drew against weekly treatments such as Zepbound and Wegovy.
"In Phase 2b studies, berobenatide delivered continuous, uninterrupted weight loss at all doses selected for Phase 3, while preserving a tolerable profile as people transitioned from a weekly to a monthly maintenance dose," said Jim List, Pfizer's chief internal medicine officer, in a Saturday press release.
List also pointed to Pfizer’s distribution reach as a strategic advantage amid a shift in obesity care toward primary care physicians. In comments reported to Bloomberg, List said, "We have primary care in our DNA."
Pfizer plans to launch an extensive clinical program in 2026 that it says will include more than 20 trials across obesity and related metabolic indications. That slate reportedly features 10 active and planned Phase 3 studies dedicated to berobenatide, along with evaluations of its effects on comorbid conditions closely linked to obesity, such as sleep apnea and knee osteoarthritis. Executives indicated an intention to extend trials geographically into China and Japan.
External clinical perspective in the presentation included remarks from John B. Buse, a professor of medicine at the University of North Carolina School of Medicine, who observed, "Weight management is a lifelong commitment, and the barriers to staying on therapy long-term are just as important as the therapy itself." He added that "if approved by regulators, berobenatide has the potential to be both practical and sustainable for patients in real-life settings."
On the manufacturing and commercial front, Pfizer said it will leverage its existing global production infrastructure to prepare for distribution. The company noted it operates eight sterile injectable facilities worldwide and signaled an intent to internalize manufacturing processes. Boshoff said in the Bloomberg interview, "We are internalizing everything, because we can," and Pfizer noted that berobenatide requires less active ingredient than some rival therapies, a factor it said could simplify large-scale production.
Overall, the company described a multi-pronged approach: advancing a broad clinical program, pursuing once-monthly dosing as a differentiator, and using established manufacturing and commercial channels to support rollout should the candidate progress through regulatory review and approval.
Context and implications
The company’s presentation emphasized both clinical outcomes and commercial preparedness as it seeks to narrow the lead held by market incumbents. Pfizer’s strategy ties clinical trial expansion to an emphasis on practical dosing frequency and a manufacturing posture designed to support broad access across multiple markets.