Detailed data are expected later, but partners Biontech SE and Duality Biologics Co. Ltd. are celebrating a phase III interim analysis readout demonstrating that HER2-targeting antibody-drug conjugate (ADC) trastuzumab pamirtecan hit the primary endpoint of progression-free survival in patients with HER2-positive unresectable or metastatic breast cancer who have previously received trastuzumab and a taxane-based chemotherapy.