Summary of Research: 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.

This is a summary of a research article reporting the findings of the HER2CLIMB-05 trial (NCT05132582), a randomized, double-blind, placebo-controlled, international, phase III trial. The HER2CLIMB-05 trial was conducted to compare the efficacy and safety of adding tucatinib versus placebo to first-line maintenance therapy (trastuzumab and pertuzumab) following induction chemotherapy, in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer. The key finding of the HER2CLIMB-05 trial was that progression-free survival was significantly improved in the tucatinib arm over the control arm (24.9 vs 16.3 months). The safety profile of tucatinib plus maintenance therapy was consistent with the known toxicities of each individual drug. The HER2CLIMB-05 regimen, with its high efficacy and manageable toxicity, represents a valuable option for first-line maintenance therapy in patients with human epidermal growth factor receptor 2-positive metastatic breast cancer.