Description
Tucatinib is an oral tyrosine kinase inhibitor specifically designed to target HER2-positive tumors, including HER2-positive metastatic colorectal cancer. This selective HER2 inhibitor is used in combination with trastuzumab and chemotherapy regimens like mFOLFOX6 for the treatment of HER2-amplified colorectal cancers. Tucatinib demonstrates activity against both extracranial disease and brain metastases in HER2-positive solid tumors. The drug is specifically indicated for patients whose tumors harbor HER2 amplification or overexpression, which occurs in approximately 2-5% of colorectal cancers.
Mechanism of Action
Tucatinib selectively inhibits the HER2 protein tyrosine kinase by binding to the ATP-binding site of the HER2 receptor, blocking downstream signaling pathways that promote tumor cell proliferation and survival. Unlike other HER2-targeted agents, tucatinib has high selectivity for HER2 over EGFR, reducing off-target effects while maintaining potent anti-HER2 activity. The drug effectively crosses the blood-brain barrier, making it particularly valuable for treating or preventing CNS metastases in HER2-positive cancers.
Molecular Targets
Side Effects
Not all side effects are listed. Side effects vary by individual. Always consult your oncologist.