Dr. Hortobagyi on MONALEESA-2 Trial Results in HR+ Breast Cancer

Gabriel N. Hortobagyi, MD, professor of Medicine at The University of Texas MD Anderson Cancer Center, discusses findings from the phase III MONALEESA-2 trial, which looked at the addition of the CDK 4/6 inhibitor ribociclib to endocrine therapy in postmenopausal women with hormone receptor (HR)-positive metastatic breast cancer.

Patients were randomized to receive letrozole at a dose of 2.5 mg/day or ribociclib at 600 mg/day for 3 weeks on, 1 week off or placebo. Treatment was continued until disease progression, and the primary endpoint was progression-free survival, Hortobagyi says.

At a follow-up, there was such a significant difference between the two arms, it was decided that the trial had reached its primary endpoint. Results showed that there was a 44% reduction in the risk of progression, with a significant P value as well, he adds.