Merck signaled a pivot in its Phase 3 development plan for Winrevair (improved benefit at the lowest dose in Phase 2) by steering toward a lower dose for a pivotal trial in an uncommon form of heart failure. The update followed a Phase 2 signal in which investigators saw “pretty profound” benefit at the lowest dose tested. The move matters for trial design, dose selection, and the eventual label shape. It also underscores the practical reality that early efficacy gradients can drive late-stage strategy, particularly when dosing affects tolerability, logistics, and potential dosing frequency. Industry participants will watch for how Merck frames the dose rationale in the Phase 3 protocol and whether endpoints and subgroup analyses are aligned to reproduce the Phase 2 benefit profile at the selected dose range.