Clinical Trial

A Phase 3, randomized, open-label, multicenter, controlled study to evaluate the efficacy and safety of zanidatamab in combination with physician’s choice chemotherapy compared to trastuzumab in combination with physician’s choice chemotherapy for the treatment of participants with metastatic HER2-positive breast cancer who have progressed on, or are intolerant to, previous trastuzumab deruxtecan treatment (JZP598-303)

MOA: Zanidatamab is a bispecific antibody targeting two distinct HER2 epitopes, ECD2 and ECD4.

Key Eligibility Criteria:

• Women and men with HER2-positive metastatic breast cancer
• Central testing of HER2 status must be performed w/in 6 mo prior to C1D1
• Most recent archival tissue or fresh biopsy must be submitted to confirm HER2 status by sponsor-designated central lab prior to randomization
• If pt meets all eligibility criteria but HER2 status is not confirmed, pts with previously assessed IHC 3+ HER2+ status will be randomized while tissue is submitted to central lab for HER2 confirmation
• Pt must have progressed on, or is intolerant to, previous T-DXd treatment
• Pt must have received 2-4 lines of HER2-directed tx in metastatic setting
• Prior HER2-targeted (neo)adj therapy that resulted in relapse w/in 6 mo considered line of therapy for metastatic disease
• Post-T-DXd therapy allowed (for ex: tucatinib-based regimen and/or T-DM1)
• Measurable disease per RECIST v1.1