Study of Trastuzumab Deruxtecan Versus Standard of Care Chemotherapy for HER2-Expressing (IHC 3+/2+) Endometrial Cancer

This is a global, multicenter, open-label, phase 3 study to evaluate the efficacy and safety of T-DXd versus SoC chemotherapy with or without radiotherapy as adjuvant treatment in participants with HER2-expressing (IHC 3+/2+) endometrial cancer. Participants will be randomized 1:1 to either T-DXd or SoC chemotherapy. The primary objective will assess disease-free survival as assessed radiographically by BICR or by histopathologic confirmation of disease recurrence per local assessment. T-DXd (Enhertu®) is a HER2 directed ADC composed of a humanized anti-HER2 IgG1 mAb with the same amino acid sequence as trastuzumab, which includes a plasma-stable, selectively cleavable linker and potent topoisomerase I inhibitor payload (a derivative of exatecan) that leverages the clinically validated DXd ADC technology.