Pfizer's obesity case now rests on a single monthly injectable

Pfizer's push into the obesity drug market now rests almost entirely on one medicine. After the company discontinued two experimental obesity candidates, MET-224o and PF-07976016, in August 2026, its remaining obesity program centers on berobenatide, an injectable drug designed to be taken once a month instead of once a week.^[2] Pfizer's chief executive, Albert Bourla, told investors on the company's second-quarter earnings call that Pfizer is "targeting a first approval in 2028" for the drug.^[1]

Berobenatide, previously called MET-097i, came to Pfizer through its 2025 acquisition of the obesity biotech Metsera. Bourla described it as an "investigational ultra-long-acting GLP-1 receptor agonist with the potential to be the first monthly GLP-1 peptide approved for the treatment of obesity and related comorbidities."^[1] Most GLP-1 drugs on the market today, including Wegovy, Zepbound, and Mounjaro, are dosed weekly. A monthly option, if it reaches pharmacy shelves, would mean fewer injections for patients who choose it.

Pfizer says it plans to advance an extensive late-stage program this year, with ten Phase 3 studies for chronic weight management and obesity-related conditions expected to move forward in 2026.^[1] Earlier Phase 2b results showed weight loss beyond what a placebo produced, of up to 12.3% at 28 weeks on the medium dose being carried into Phase 3, and roughly 16% average weight loss over 32 weeks at the highest weekly dose tested.^[2] Bourla pointed to data presented at the American Diabetes Association's Scientific Sessions as reinforcing the company's confidence in the drug.^[1]

The stakes are large. Pfizer's leadership has said it sees the obesity and related-conditions market reaching $150 billion, and the broader obesity therapeutics market has been estimated by IQVIA at $66 billion last year, with projections of $105 billion to $200 billion by 2027 and beyond.^[1][2] Analysts covering the sector have said berobenatide's ultimate value to Pfizer will depend heavily on how it performs in the Phase 3 trials expected to read out around 2028.^[2]

Why it matters for patients

For people currently using or considering GLP-1 medicines, this development does not change what is available today. Wegovy, Zepbound, Mounjaro, Ozempic, and Foundayo remain on the market under their existing approvals, and none of Pfizer's changes affect access to those drugs.^[2]

What this news signals is where a possible new competitor stands. A monthly injection, if it is eventually approved, could offer an alternative dosing schedule for people who want fewer shots. But berobenatide is still years from approval, and Pfizer's own target date of 2028 is not a guarantee; Phase 3 trials can fail or take longer than planned. Patients should not expect this drug to be available soon, and no dosing, safety, or effectiveness conclusions can be drawn yet from the mid-stage results described by the company.^[1][2]

The narrowing of Pfizer's pipeline to a single obesity asset also means the company now has less room for error. If berobenatide's Phase 3 results disappoint, Pfizer would have no immediate backup obesity drug in its own pipeline, since MET-224o and PF-07976016 were both cut in August.^[2]

What happens next

Three Phase 3 trials, named VESPER-4, VESPER-5, and VESPER-6, are already underway.^[2] Pfizer says it expects to start additional late-stage studies during 2026, including a trial testing whether patients can switch from an already-approved weekly GLP-1 therapy to monthly berobenatide dosing.^[2] Full Phase 3 results, which analysts say will determine the drug's commercial value, are expected around 2028, the same year Pfizer has targeted for a possible first approval.^[1][2]