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 HER2CLIMB-05, a randomised phase 3 trial 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, so far approved for later-line disease on the basis of the HER2CLIMB trial; this study tests moving it earlier in the treatment sequence. HER2 overexpression is present in approximately 15-20% of metastatic breast cancers.