TUKYSA, generically known as tucatinib, is a targeted therapy medication used in the treatment of certain types of breast cancer. Specifically, it is designed for patients with HER2-positive breast cancer, which is characterized by an overexpression of the human epidermal growth factor receptor 2 (HER2) protein. TUKYSA works by selectively inhibiting the activity of the HER2 protein, thereby helping to stop or slow the growth of cancer cells that overexpress this receptor. It is often used in combination with other cancer treatments, such as chemotherapy or other targeted therapies, to enhance its effectiveness. Approved by regulatory agencies in various countries, TUKYSA represents a significant advancement in the targeted treatment approach for patients battling this aggressive form of breast cancer.