ERBB3 and head and neck squamous cell carcinoma: Notably, HERTHENA-PanTumor01 (NCT06172478) is evaluating HER3-DXd, a HER3-directed ADC with demonstrated activity in EGFR-mutant metastatic NSCLC and breast cancer, in previously treated cutaneous melanoma, HER2-negative gastric cancer, and HNSCC.