The efficacy and safety of zanidatamab in combination with physician's choice of chemotherapy compared with trastuzumab in combination with physician's choice of chemotherapy will be evaluated for the treatment of participants with metastatic HER2-positive breast cancer who have progressed on, or are intolerant to, previous T-DXd treatment.
Is 18 years of age or of the legal adult age per local standard at the time of signing the informed consent.
Has histologically confirmed HER2-positive breast cancer according to ASCO-CAP Guidelines as evaluated by a sponsor-designated central laboratory
Participants with unresectable or metastatic HER2 positive breast cancer who have progressed on, or are intolerant to, previous T-DXd treatment.
Must have received at least 2 lines of HER2-directed therapy for their metastatic disease.
None