Tucatinib (Tukysa®)

This is a small molecule tyrosine kinase inhibitor (TKI), given orally, that prevents HER2 proteins from helping cancer cells to grow. It’s used with the drug trastuzumab (Herceptin®), an antibody drug that also targets HER2 proteins, and chemotherapy to treat metastatic HER2-positive breast cancer in those whose cancers can’t be removed with surgery (inoperable) and have received previous treatments.