HER2CLIMB-05 results: impact of tucatinib/tucatinib in the maintenance setting

The application of Tucatinib/Tucatinib (Tucatinib) in the maintenance treatment of HER2-positive metastatic breast cancer has received increasing attention. The original HER2CLIMB study showed that tucatinib in combination with trastuzumab could significantly improve the efficacy of capecitabine, especially in patients who have failed to respond to multiple conditioning drugs. Based on this study, the HER2CLIMB-05 study further explored the effect of tucatinib in first-line maintenance therapy. The primary objective of the study was to evaluate whether continuing tucatinib and trastuzumab after patients discontinue taxane therapy can further improve treatment efficacy.

The results of the HER2CLIMB-05 study showed that tucatinib combination therapy can significantly extend progression-free survival (PFS). In this study, PFS was extended from approximately 18 months to more than 2 years, and the difference was highly statistically significant. In particular, progression-free survival was extended by more than 12 months in patients with HR-negative breast cancer and 6.9 months in patients with HR-positive breast cancer. These results further demonstrate the broad efficacy of tucatinib in different subgroups of patients. In addition, the study also analyzed the progression-free survival of the central nervous system (CNS). Although the median CNS progression-free survival of the two groups of patients did not reach statistical significance, among patients with known brain metastases, the central nervous system progression-free survival of the tucatinib group was significantly improved, showing a more optimistic outlook.

In terms of safety, tucatinib shows similar side effects to other treatments for HER2-positive breast cancer, including diarrhea and increased liver function. Data from the HER2CLIMB-05 study showed that approximately 13% of patients discontinued treatment due to adverse events, including 7.7% of patients who discontinued treatment due to elevated liver enzymes (AST and ALT). However, most of these liver function abnormalities are asymptomatic and can be alleviated by adjusting the drug dose. In terms of diarrhea, the incidence of diarrhea in the tucatinib group was slightly higher than 70%, but diarrhea was not the main reason for discontinuation. Only 1.5% of patients discontinued tucatinib due to diarrhea, compared with a slightly lower incidence of diarrhea in patients treated with trastuzumab and pertuzumab alone.

The successful application of tucatinib inmaintenance treatment of HER2-positive metastatic breast cancer provides patients with more treatment options. Based on the results of the HER2CLIMB-05 study, maintenance therapy with tucatinib has become an option worth considering, especially for patients who achieve partial or complete responses to first-line treatment. Future studies will continue to explore the effects of additional maintenance treatment regimens, especially in combination with other medications.

In addition,Maintenance treatment of HER2-positive metastatic breast cancer still faces several challenges. Although tucatinib has shown good efficacy in the maintenance phase, how to further optimize the treatment plan, improve patients' quality of life, and reduce side effects is still an important direction for future research. Similar to the Patina study, the maintenance treatment regimen for ER-positive patients also deserves attention, as it provides more reference for the maintenance treatment of HER2-positive patients. Future studies may combine different targeted therapies and immunotherapies to further improve patient outcomes and prognosis.

References: UpdatedDecember 16, 2025, https://www.docwirenews.com/post/her2climb-05-results-dr-erika-hamilton-explains-tucatinibs-impact-in-the-maintenance-setting