HER2CLIMB-05: A Phase III Study of Tucatinib Versus Placebo in Combination With Trastuzumab and Pertuzumab as First-Line Maintenance Therapy for HER2+ Metastatic Breast Cancer

The Journal of Clinical Oncology has published the HER2CLIMB-05 trial, a Phase III randomized study evaluating the addition of tucatinib to the standard first-line backbone of trastuzumab and pertuzumab as maintenance therapy in HER2-positive metastatic breast cancer. Tucatinib is a highly selective oral HER2-targeted tyrosine kinase inhibitor already approved for later-line HER2-positive disease based on the landmark HER2CLIMB trial, and this study aims to move its use earlier in the treatment sequence. The trial addresses a significant unmet need, as maintenance strategies after first-line induction in HER2-positive metastatic breast cancer remain an area of active investigation. Publication in JCO underscores the clinical importance of these findings for the management of approximately 15-20 percent of all metastatic breast cancers that overexpress HER2.