Tucatinib in combination with trastuzumab and capecitabine is in clinical development for the treatment of unresectable or metastatic HER2-positive breast cancer. In HER2- positive breast cancer, the cancer cells have too much of a protein called HER2 on their surface. In normal cells, HER2 helps control cell growth. When it is made in larger than normal amounts by cancer cells, the cells may grow more quickly and are more likely to spread to other parts of the body. Metastatic breast cancer is cancer that has spread beyond the breast and nearby lymph nodes to other organs in the body, unresectable cancer cannot be treated with surgery.
Tucatinib is an oral medicine that is a tyrosine kinase inhibitor of the HER2 protein. By inhibiting HER2, it is hoped tucatinib will inhibit the growth of HER2-positive tumours. If licenced, tucatinib in addition to trastuzumab and capecitabine will provide an additional treatment option for adults with advanced HER2 positive metastatic breast cancer.