ASCO 2017: MONALEESA-2 Update on Combination of Ribociclib and Letrozole
Posted: Tuesday, June 20, 2017
Presented as a poster session at the 2017 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract 1038), the updated findings of the phase III MONALEESA-2 trial confirm the benefits of the first-line use of ribociclib plus letrozole in hormone receptor–positive, HER2-negative advanced or metastatic breast cancer. After an additional 11 months of follow-up, principal investigator Gabriel N. Hortobagyi, MD, FACP, of The University of Texas MD Anderson Cancer Center in Houston, and colleagues reported longer progression-free survival in patients who received the combination therapy than in those who received letrozole alone.
In this trial, 668 patients were enrolled, with 334 receiving the cyclin-dependent kinase 4/6 inhibitor ribociclib and the aromatase inhibitor letrozole and 334 receiving letrozole and placebo. The median progression-free survival with ribociclib plus letrozole was 25.3 months, versus 16.0 months with letrozole alone (P<.0001). The 24-month progression-free survival rates were 54.7% with the combination therapy and 35.9% with the single-agent therapy. The benefit of treatment with ribociclib and letrozole seemed to be consistent across patient subgroups, the investigators noted.
The study remains immature for overall survival analysis.