Xenofon Vakalis, Radiation Oncologist at Medical center of Athens, shared on LinkedIn:
“HER2CLIMB-05: A New Step in HER2+ Metastatic Breast Cancer – But Is It Practice-Changing?
On October 7, 2026, the FDA approved tucatinib + trastuzumab + pertuzumab as maintenance therapy following taxane-based induction in advanced HER2+ breast cancer.
The phase III HER2CLIMB-05 trial (654 patients) demonstrated a significant improvement in progression-free survival (PFS):
Median PFS:
- Tucatinib + HP: 24.9 months
- Placebo + HP: 16.3 months
- HR 0.64 (95% CI 0.51–0.80; p lt; 0.0001)
An impressive 8.6-month difference in median PFS. However, several questions remain.
- Overall survival: Data remain immature. Longer PFS does not necessarily translate into longer survival.
- Treatment sequencing: Is earlier tucatinib better than reserving it for subsequent lines, particularly in the evolving trastuzumab deruxtecan era?
- Brain metastases: Despite tucatinibs established CNS activity, the CNS-PFS subgroup analysis did not demonstrate a statistically significant benefit (HR 0.719; 95% CI 0.406–1.273).
- Toxicity matters: Grade ≥3 adverse events occurred in 42.3% versus 24.4%, with increased diarrhea and hepatotoxicity.
- Quality of life: The clinical value of prolonged disease control must be weighed against the burden of continuous treatment.
The bottom line:
HER2CLIMB-05 provides compelling evidence for improved disease control, but not yet for improved overall survival.
The key question is not simply whether we can delay progression, but whether earlier treatment intensification ultimately improves survival and quality of life.
Promising results – but patient selection and optimal sequencing remain critical.”
Title: 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
Authors: Veronique Dieras, Giuseppe Curigliano, Miguel Martin, Florence Lerebours, Junji Tsurutani, Marie-France Savard, Katarzyna J. Jerzak, Xichun Hu, Luciana Carla Martins de Aquino Pimentel, Ciara C. O’Sullivan, Eriko Tokunaga, Alicia Okines, Chiun-Sheng Huang, William Jacot, Joohyuk Sohn, Eduardo Cronemberger Silva, Volkmar Mueller, Shan Yang, Giovanna Granata, Qi Shen, Libero Santarpia, Erika Hamilton.
Read the full article.
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