Dr. Tolaney on Key Findings From the ExteNET Trial in HER2+ Breast Cancer

Sara M. Tolaney, MD, MPH, associate director, Susan F. Smith Center for Women's Cancers, director, Clinical Trials, Breast Oncology, director, Breast Immunotherapy Clinical Research, senior physician, Dana-Farber Cancer Institute; and associate professor of medicine, Harvard Medical School, discusses data from the phase 3 ExteNET trial (NCT00878709) utilizing neratinib (Nerlynx) in the treatment of patients with HER2-positive breast cancer.

ExteNET enrolled patients with high-risk HER2-positive breast cancer. The trial examined the administration of 1 year of neratinib vs placebo in those who had completed a full year of trastuzumab (Herceptin). Results indicated that neratinib significantly improved invasive disease-free survival (iDFS) in this population, particularly in those with hormone receptor (HR)–positive disease, according to Tolaney.

Several subsequent exploratory analyses of the trial have demonstrated that when neratinib is initiated within 6 months of trastuzumab in this high-risk subset of patients who have HR-positive, HER2-positive disease, who did not achieve a prior pathologic complete response, it resulted in a significant iDFS and overall survival benefit.

These analyses also found numerically fewer brain metastases as a site for recurrence, making this study the first to show an impact on incidence of central nervous system metastases with adjuvant therapy, Tolaney concludes.