Coming right after its bidding war with Novo Nordisk to purchase Metsera, Pfizer has announced its very first readout of the company’s obesity pipeline, claiming weight loss greater than 12 percent at the upper dose amount discussed. BMO Capital Markets wrote to investors saying Pfizer was charging into obesity clinical development.
In the Phase IIb VESPER-3 study, Pfizer showed the results of the long-acting GLP-1 MET-097i injectable (now referred to as PF ‘3944). Initial dosing was done as a weekly subcutaneous injection of the drug to start patients, then changed to monthly. According to a news release, the trial involved four titration protocols, which included different strengths and schedules, and a placebo control arm.
On the medium dose arm, which consisted of 0.4 mg of weekly injections slowly increasing to 1.2 mg, then 4.8 mg monthly, the patients obtained 12.3 percent placebo-adjusted weight loss at week 28. A low-dose arm, which peaked at 3.2 mg monthly injections, achieved 10 percent placebo-adjusted weight loss.
In a separate note to investors, analysts at BMO Capital Markets said that such weight-loss results are competitive with other commercially available therapies. The group provided an example of Novo semaglutide that achieved a placebo-adjusted percentage of 9 at 28 weeks at Phase III STEP-1. At the same time point, tirzepatide in Eli Lilly reached 13% in the Phase III SURMOUNT-1 trial.
The plateau effect was not observed in patients in both treatment groups at the readout time, at which Pfizer stated to indicate the strong and sustained weight loss with PF ‘3944 despite a monthly dosing regimen. The pharma anticipates that the body weights of the patients will keep on reducing through 64 weeks follow up treatment.
The company said that Pfizer will proceed with the low and medium dose schedules into the Phase III development.
Pfizer has a comprehensive late-stage program in PF3944, which will have 10 Phase III trials, with different types of patients and comorbidities. These consist of the newly introduced VESPER-4 that will examine weekly doses in patients with or without type 2 diabetes who are either obese or overweight. A second trial, known as VESPER-5, will be based on individuals with type 2 diabetes.
Other than such monotherapy trials, there will be another group of investors who will be looking at possible combination regimens with MET-233i, an amylin asset that was also part of the Metsera purchase, according to BMO.
The information on the combination with [PF3944] and the relative competitive profile of the asset, the analysts stated, will be essential moving forward in assessing Pfizer in the changing obesity market environment.
Pfizer had already intended to buy Metsera in September last year at a price of $ 4.9 billion, an offer that was readily surpassed by the offer made by Novo at 8.5 billion dollars. A ruthless, not to mention disordered, bidding war took place, and although Pfizer emerged as a winner, the price could be highly paid- about 10 billion dollars.
And although the data on PF ‘3944 are said to be favoring a competitive mono-agonist profile, it still leaves some questions to be posed as Pfizer gears up for a complete release in June this year, BMO said.
What the Metsera Weight-Loss Results Show
According to early readouts, Pfizer’s Metsera-sourced PF’3944 (formerly MET-097i) achieved up to approximately 12.3% placebo-adjusted weight loss at 28 weeks in a Phase IIb study — strong performance compared with existing treatments — with continuous reduction after switching to monthly dosing.
Why Metsera Matters for Pfizer’s Obesity Strategy
The acquisition of Metsera gives Pfizer access to a pipeline of obesity and metabolic candidates, including monthly injectable and once-weekly GLP-1 receptor agonists. These Metsera assets are designed to compete with current market leaders and help Pfizer re-enter the weight-loss drug space dominated by rival companies
