Successfully treated breast cancer often comes back, with recurrence possible in the same area as the original tumor, in the same region as the original tumor, or having spread to different parts of the body. The latter is known as metastatic breast cancer. The possibility of such recurrence is a concern for all breast cancer patients, but a recent trial finds that a new drug therapy may cut the risk by about 25%.
Swiss drugmaker Novartis recently released the findings of a Phase III trial testing the effectiveness of Kisqali, or ribociclib, which targets CDK4 and CDK6, breast cancer cell proteins that cause cell division. It’s already been approved throughout much of the world and has been used for patients with metastatic breast cancer.
The NATALEE trial – the findings of which were presented at the 2023 American Society of Clinical Oncology Annual Meeting – tested Kisqali with hormone therapy, versus hormone therapy only, in more than 5,100 patients with stage II and III hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) breast cancer. Over a median follow-up period of three years, all received hormone therapy, while half also received Kisqali.
A news release from Novartis also noted improvements in distant disease-free survival, recurrence-free survival, and overall survival.
Dr. Dennis J. Slamon, the trial’s lead researcher and Director of Clinical/Translational Research at UCLA Jonsson Comprehensive Cancer Center, says, “These landmark results will fundamentally change how we treat patients with stage II and III HR+/HER2- early breast cancer who are in need of new, well-tolerated options that prevent their cancer from coming back.”
Dr. Sheeram Aradhye, President of Global Drug Development and Chief Medical Officer at Novartis, adds, “Patients diagnosed with HR+/HER2- early breast cancer remain at risk of cancer recurrence, given that one-third of patients diagnosed with stage II and more than half of those diagnosed with stage III will unfortunately experience a return of their cancer. The compelling data from NATALEE highlight the potential of Kisqali to reduce the risk of cancer recurrence in this at-risk population, including node-negative patients, while maintaining a favorable safety profile.”
Among the more common side effects were low counts of white blood cells called neutrophils and elevated liver enzymes. A small number of patients also experienced diarrhea.
Novartis says it plans to submit the trial’s findings to U.S. and European regulatory authorities by the end of the year to allow for wider use.