Trastuzumab Deruxtecan (DS-8201a) Versus Investigator's Choice for HER2-low Breast Cancer That Has Spread or Cannot be Surgically Removed [DESTINY-Breast04]

This is a randomized, 2-arm, Phase 3, open-label, multicenter study to compare the safety and efficacy of trastuzumab deruxtecan versus the physician's choice (2:1) in HER2-low, unresectable and/or metastatic breast cancer participants. The Sponsor proposes to define a new HER2-low population in this trial including tumors with IHC 1+ and IHC 2+/ISH- HER2 expression.