GSK and the GOG Foundation initiated a Phase 3 global trial evaluating mocertatug rezetecan in platinum-resistant ovarian cancer, with enrollment of the first patient. The study, GOG-3132/BEHOLD-Ovarian01 (NCT07286266), compares the investigational therapy with standard-of-care chemotherapy in a setting where chemotherapy options have limited durability. The first-patient enrollment marks a key clinical pivot from earlier development into a registrational path designed to clarify comparative benefit and safety. For oncology teams, the trial start also adds another DNA damage–targeting option to a crowded platinum-resistant landscape, where sequencing and endpoint selection increasingly drive regulatory prospects. The trial’s “global Phase 3” framing indicates a broad enrollment effort intended to support later regulatory submissions in multiple jurisdictions.