Key clinical point: Addition of tucatinib to trastuzumab and capecitabine continued to improve survival along with good tolerability in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (BC) who progressed on HER2-targeted therapies.
Major finding: Addition of tucatinib to trastuzumab and capecitabine significantly improved overall survival (hazard ratio [HR] for death, 0.73; P = .004) and progression-free survival (HR for disease-progression or death, 0.57; P < .00001) compared with placebo. Rates of grade 3 or higher adverse events (AEs) were similar between treatment arms, with only 5.9% of patients discontinuing treatment because of AEs.
Study details: These are the final outcomes from the phase 2 HER2CLIMB study including 612 patients with HER2-positive metastatic BC who progressed on trastuzumab, pertuzumab, and trastuzumab emtansine and were randomly assigned to tucatinib or placebo, each in combination with trastuzumab and capecitabine.
Disclosures: This work was supported by Seagen Inc. and Merck Sharp & Dohme Corp. Four authors declared being employees of Seagen and other sources, and other authors reported ties with various sources.
Source: Curigliano G et al. Ann Oncol. 2021 Dec 22. doi: 10.1016/j.annonc.2021.12.005 .