Tucatinib for First-Line Maintenance Therapy in HER2-Positive Metastatic Breast Cancer
Key Clinical Takeaways
- Adding tucatinib to trastuzumab and pertuzumab for first-line maintenance therapy significantly prolonged investigator-assessed progression-free survival compared with standard maintenance alone (HR 0.641; P <.0001). Benefit was consistent across all prespecified patient subgroups, regardless of hormone receptor status or presence of baseline brain metastases.
- Early overall survival data suggest a favorable trend, though results are still immature. Tucatinib’s safety profile remained manageable, with diarrhea, nausea, and elevated liver enzymes as the most common treatment-emergent adverse events.
- Findings support tucatinib-based maintenance as a promising strategy to extend disease control for HER2+ metastatic breast cancer after completion of induction chemotherapy.
Erika Hamilton, MD, Sarah Cannon Research Institute, Nashville, Tennessee, discusses results from the phase 3 HER2CLIMB-05 trial evaluating whether the addition of tucatinib to trastuzumab and pertuzumab as first-line maintenance therapy can improve outcomes for patients with HER2-positive metastatic breast cancer following taxane-based induction.
The study demonstrated a statistically significant and clinically meaningful progression-free survival benefit across all prespecified subgroups, including patients with and without baseline brain metastases. Safety findings were consistent with the known tucatinib profile, supporting its potential role as an intensified maintenance strategy.
These findings were presented at the 2025 San Antonio Breast Cancer Symposium in San Antonio, Texas.
Source:
Hamilton E, Curigliano G, Martin M, et al. Her2climb-05: a randomized, double-blind, phase 3 study of tucatinib versus placebo in combination with trastuzumab and pertuzumab as maintenance therapy for her2+ metastatic breast cancer. Presented at SABCS 2025. December 9 - 12, 2025. San Antonio, Texas. Abstract GS1-01
