A Phase IIIb, Open-label, Multinational Study Assessing the Efficacy and Safety of Dato-DXd Treatment in Patients With HRpositive, HER2 IHC 0, Locally Advanced Inoperable or Metastatic Breast Cancer Refractory to Endocrine Therapy (TROPION-Breast06)

This is a Phase IIIb, single-arm, open-label, multicentre, multinational study assessing the efficacy and safety of Dato-DXd in participants with HR-positive, HER2 IHC 0, locally advanced inoperable or metastatic breast cancer refractory to endocrine therapy. Refer to the study schema (Figure 1) and SoA (Section 1.3) for overall design and required assessments. Day 1 is defined as the first day of study treatment. Approximately 100 participants will be treated in this study with Dato-DXd 6 mg/kg as an intravenous infusion every 3 weeks (21-day cycle), up to a maximum of 540 mg for patients ≥…