By Elaine ChenJune 6, 2026
Chen, a national biotech reporter, is the co-author of The Readout, a newsletter about the business, science, and politics of biotech.
Elaine’s stories explore the boom in new obesity treatments, new drug payment models, the ways companies are affected by FDA changes, and the emerging psychedelics drug sector. She co-writes The Readout newsletter, and co-hosts STAT’s weekly biotech podcast, The Readout Loud. You can reach Elaine on Signal at elaineywchen.70.Detailed data from a mid-stage study offered further evidence that the obesity drug Pfizer acquired from the biotech Metsera could be dosed monthly. But it’s not clear how competitive the treatment would be against weekly injectables on the market and in development that may lead to greater weight loss.
In the study, called VESPER-3, patients with obesity took weekly doses of the drug, called berobenatide, for 12 weeks and then transitioned to higher monthly doses out to 28 weeks. By then, patients lost up to 12.1% of their weight, when analyzing just those who stayed on treatment, as Pfizer previously reported.
New data presented at the annual meeting of the American Diabetes Association on Saturday show that when patients transitioned from weekly to monthly dosing, the rate of weight loss continued at a similar pace; they had not yet hit a plateau by 28 weeks. That’s a promising sign, but the rate of weight loss at 28 weeks was still less than what was seen at a similar time point in the pivotal trial of Eli Lilly’s Zepbound.
