Dr. Sara Tolaney on Cabozantinib in Breast Cancer

Sara M. Tolaney, MD, MPH, Instructor in Medicine, Harvard Medical School, Medical Oncologist, Clinical Investigator, Dana-Farber Cancer Institute and Brigham and Women's Hospital, discusses trials investigating cabozantinib in breast cancer.

Cabozantinib is a multi-targeted tyrosine kinase inhibitor aimed at mutations in MET, VEGFR2, and RET. It was recently approved for the treatment of metastatic medullary thyroid cancer and is being explored as a therapy for numerous tumor types, including breast cancer.

In a phase II randomized discontinuation trial, which Tolaney highlights, cabozantinib showed a 14% rate of objective tumor regression in patients with heavily pretreated metastatic breast cancer. There is some rationale, Tolaney says, to analyze cabozantinib in ER-positive breast cancer with bone metastases, due to impressive bone scans and bone pain responses in the trial.

Additionally, Tolaney states, there is reason to explore cabozantinib in patients with triple-negative breast cancer (TNBC) since MET, a target for cabozantinib, is often overexpressed to a higher degree in TNBC than in ER-positive breast cancer.