Advancing treatment in HER2-positive metastatic breast cancer: the role of tucatinib.

Tucatinib has significantly advanced the treatment of HER2-positive metastatic breast cancer. When used in combination with trastuzumab and capecitabine, it improves survival for heavily pretreated patients, including patients with brain metastases. Its efficacy was demonstrated in the HER2CLIMB trial and it stands as an optimal choice for patients with brain metastases, a patient population who have historically been excluded from clinical trials. Tucatinib is orally administered and has a manageable safety profile. Common adverse events include diarrhea, nausea, fatigue, and liver enzyme elevations, which are typically manageable with dose modifications and supportive care. With strong clinical efficacy and widespread approval since 2020, tucatinib remains an important treatment option for patients with HER2-positive metastatic breast cancer.