Pfizer used ADA to extend clinical evidence that berobenatide, acquired from Metsera, can be dosed monthly after an initial weekly phase. In the VESPER-3 mid-stage study, patients took berobenatide weekly for 12 weeks before transitioning to higher monthly doses through 28 weeks. By 28 weeks, patients lost up to 12.1% of body weight among those who stayed on treatment, and Pfizer reported that weight loss continued at a similar pace after the weekly-to-monthly switch rather than plateauing. The company positioned the result as validation for a monthly regimen. Still, the disclosure also underscored the competitive challenge of matching weight-loss depth and durability seen with weekly injectables in pivotal comparisons—leaving analysts to watch how efficacy and safety ultimately balance across dosing schedules.