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
In brief
Tucatinib extends progression-free survival by roughly nine months in HER2-positive metastatic breast cancer maintenance
In the phase III HER2CLIMB-05 trial, adding tucatinib to trastuzumab-pertuzumab after induction chemotherapy lengthened median progression-free survival to 24.9 months versus 16.3 months with placebo. Toxicities were as expected and manageable, suggesting tucatinib-based maintenance is a strong new option, though overall survival and long-term safety remain to be clarified.
- Journal
- Targeted oncology (Q1)
- Published
- 19 September 2026
- Study design
- Randomized controlled trial
- Evidence level
- Level 1, High (CEBM 1b)
- Authors
- Veronique Dieras, Giuseppe Curigliano, Miguel Martin, Florence Lerebours, Junji Tsurutani, Marie-France Savard, et al.
- PMID
- 42762393
- DOI
- 10.1007/s11523-026-01245-w
Why clinicians should know about it
- Picked for Oncology and Radiation Oncology (top studies of the week, 20 September 2026): Recent Oncology and Radiation Oncology research from a high-quartile journal
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Abstract
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.
Abstract as published, via PubMed.
For healthcare professionals. The summary is generated by AI from the published abstract, and the evidence level is assigned automatically from the study design on the Oxford CEBM hierarchy. Neither is medical advice. Read the full paper before changing practice.