Biomarker-Stratified Phase II Trial of Trastuzumab Rezetecan in Advanced Salivary Gland Carcinoma Across Cohorts With High and Low Human Epidermal Growth Factor Receptor 2 Expression

A biomarker-stratified phase II trial evaluated trastuzumab deruxtecan (T-DXd), a HER2-directed antibody-drug conjugate, in patients with advanced salivary gland carcinoma across cohorts defined by high and low HER2 expression. The study, published in the Journal of Clinical Oncology, addresses a critical unmet need in this rare malignancy with very limited systemic therapy options. By stratifying enrollment by HER2 status, the trial provides key data on whether T-DXd activity extends beyond HER2-high tumors in this histology, mirroring the HER2-low paradigm established in breast cancer.