Dr. Paplomata on the Clinical Impact of Tucatinib in HER2+ Breast Cancer

Elisavet Paplomata, MD, assistant professor, University of Wisconsin School of Medicine and Public Health, oncologist, University of Wisconsin Carbone Cancer Center, discusses the clinical impact of tucatinib (Tukysa) in HER2-positive breast cancer.

Tucatinib, in combination with trastuzumab (Herceptin) and capecitabine (Xeloda), should be considered in the third-line setting for patients who progress on ado-trastuzumab emtansine (T-DM1; Kadcyla), according to Paplomata.

Moreover, high-level evidence demonstrated significant efficacy and tolerability with the tucatinib-based regimen versus trastuzumab/capecitabine alone in the phase 2 HER2CLIMB trial in patients with heavily pretreated, unresectable locally advanced or metastatic HER2-positive breast cancer, Paplomata explains. The regimen was approved by the FDA in April 2020.

Regarding safety, all-grade diarrhea occurred in about 80% of patients who received tucatinib compared with 53% who received the control regimen, Paplomata says. However, diarrhea was well managed with anti-diarrheal medications and did not require prophylactic treatment.

Additionally, some patients developed liver function test abnormalities; however, these were managed with dose interruptions or dose reductions, Paplomata says.

Specifically, the data from the HER2CLIMB trial also strongly suggest that tucatinib/trastuzumab/capecitabine should be considered for patients with brain metastases, concludes Paplomata.