Promising Results for a Tukysa Drug Against Breast Cancer

Results from an advanced-stage clinical trial have shown that Pfizer’s drug Tukysa, when used alongside maintenance therapy, significantly helped delay the progression of breast cancer in patients with HER2-positive metastatic breast cancer, also known as stage IV breast cancer. Tukysa, chemically known as tucatinib, belongs to a class of drugs called tyrosine kinase inhibitors, which block the HER2 protein in cancer cells, helping to slow down or stop tumor growth. The drug has already been approved for use in the treatment of colorectal cancer and advanced-stage breast cancer. A total of 654 patients, all diagnosed with stage IV cancer, completed treatment with chemotherapy in addition to the antibody drugs Herceptin (trastuzumab) and Perjeta (pertuzumab), produced by Roche, without disease progression. All patients then moved to maintenance therapy using Herceptin and Perjeta, and were randomly assigned to receive either Tukysa or a placebo. After an average follow-up period of 23 months, results showed no disease progression among patients who received Tukysa for more than two years. Data presented at the San Antonio Breast Cancer Symposium and published in the journal Clinical Oncology indicated an improvement of eight months compared with patients who received the placebo. Erika Hamilton, a professor at the Sarah Cannon Research Institute in Nashville and lead author of the study, said in a statement that the results confirm the importance of enhancing HER2 targeting during the maintenance phase. She added, “Extending the maintenance phase allows patients to continue fighting the disease while simultaneously prolonging their break from chemotherapy.”