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

Brief Summary:
This study will compare DS-8201a to physician choice standard treatment.
Participants must have HER2-low breast cancer that has been treated before.

Participants' cancer:
- Cannot be removed by an operation
- Has spread to other parts of the body

Detailed Description:
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.


Study Type: Interventional  (Clinical Trial)
Estimated Enrollment: 540 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: Parallel model, randomized at a 2:1 ratio
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: A Phase 3, Multicenter, Randomized, Open-label, Active Controlled Trial of DS-8201a, an Anti-HER2-antibody Drug Conjugate (ADC), Versus Treatment of Physician's Choice for HER2-low, Unresectable and/or Metastatic Breast Cancer Subjects
Actual Study Start Date: December 27, 2018
Estimated Primary Completion Date: January 1, 2023
Estimated Study Completion Date: January 1, 2023

Arms:
- Experimental: Trastuzumab deruxtecan
- Active Comparator: Physician's Choice