First-Line Ribociclib and Letrozole in Advanced Breast Cancer
Adding the cyclin-dependent kinase 4/6 inhibitor ribociclib to letrozole prolonged progression-free survival compared with letrozole alone in the first-line treatment of patients with hormone receptor–positive, HER2-negative advanced breast cancer. The duration of response and tumor shrinkage results from this phase III MONALEESA-2 study, led by Wolfgang Janni, MD, PhD, of the University of Ulm, Germany, were presented at the 2017 European Society for Medical Oncology (ESMO) Congress (Abstract 245PD).
The MONALEESA-2 trial is the study on which the U.S. Food and Drug Administration approved ribociclib in combination with an aromatase inhibitor as initial endocrine-based therapy for women with this type of advanced or metastatic breast cancer.
A total of 668 postmenopausal women with hormone receptor–positive, HER2-negative advanced breast cancer were enrolled. These patients, who had received no prior systemic therapy for their advanced disease, were treated with the combination of ribociclib and letrozole or letrozole and placebo.
More patients in the ribociclib/letrozole arm had a complete or partial response (53%) than in the placebo group (37%). Additionally, the mean percent change in tumor size was greater with the combination therapy for all tumor evaluations for the first 18 months.