Adverse reactions and countermeasures during tucatinib/tucatinib treatment

Tucatinib/Tucatinib, as a kinase inhibitor, has been widely used in combination treatment with trastuzumab and capecitabine. It is mainly targeted at adult patients with advanced unresectable or metastatic HER2-positive breast cancer, especially those who have experienced one or more anti-HER2-based treatment regimens and may develop brain metastases. At the same time, tucatinib has also demonstrated its therapeutic value for patients with RAS wild-type HER2-positive, unresectable or metastatic colorectal cancer whose disease has progressed after chemotherapy with fluoropyrimidine, oxaliplatin, and irinotecan.

However, patients may encounter a series of adverse reactions during treatment with tucatinib. In practice, almost all patients receiving this combination experience these side effects to some degree. According to statistics, at least one-fifth of patients require dose adjustment or temporary discontinuation of treatment, and about 6% of patients even need to permanently stop treatment.

As a new drug for the treatment of breast cancer and colorectal cancer, tucatinib has played a positive role in improving the prognosis of patients. Common adverse reactions include diarrhea, palmoplantar red blood cell paresthesia (also known as hand-foot syndrome), nausea and vomiting, abdominal pain, fatigue, muscle and joint pain, cough, dyspnea, pyrexia, lymphopenia, anemia, and increased aminotransferase levels. Although rare, serious adverse events such as severe diarrhea, hepatotoxicity, and potential toxicity to the embryo and fetus may occur. Of note, some toxicities associated with the use of tucatinib may also be associated with concomitant use of trastuzumab and capecitabine.