Further Exploration of the HER2CLIMB Regimen in Pretreated HER2 Breast Cancer

Guiseppe Curigliano, MD, an associate professor of Medical Oncology at the University of Milano and the head of the Division of Early Drug Development at the European Institute of Oncology, discusses the rationale behind a subgroup HER2CLIMB (NCT02614794) study, which evaluated the efficacy and safety of tucatinib (Tukysa) in combination with trastuzumab (Herceptin) and capecitabine (Xeloda) in pretreated HER2-positive breast cancer patients (TKI) with and without brain metastases compared with placebo.

According to Curigliano, the rationale behind the analysis was determine how a dual blockade would interact with tucatinib, a highly selective HER2-directed tyrosine kinase inhibitor. It was hypothesized that not only would this combination have efficacy in HER2-positive breast cancer patients without central nervous system involvement, but also those with brain metastases.

The HER2CLIMB study is the only study of HER-positive breast cancer patients to include patients with untreated and active brain metastases, according to Curigliano. Additionally, the confirmed overall survival (OS) benefit observed led to the HER2CLIMB-02 study (NCT03975647)

0:08 | The rationale behind this study was to provide a duel blockade with tucatinib in combination with trastuzumab and capecitabine in patients that were progressing on the duel blockade with pertuzumab [Perjeta]/trastuzumab and T-DM1. The rationale of the study, of course, was related to the capability of tucatinib, very highly selective HER2-directed tyrosine kinase inhibitor, to have major activity in combination to trastuzumab, and potentially to be active also in patients with brain metastases. In fact, this is the only study in the population of metastatic HER2-positive breast cancer population to include also patients with untreated and active brain metastases. And the confirmation of OS benefit can suggest that there is the strong rationale to use to tucatinib in combination with trastuzumab and capecitabine.