The FDA has approved Kisqali (ribociclib, formerly known as LEE011) in combination with an aromatase inhibitor as initial endocrine-based therapy for treatment of postmenopausal women with hormone receptor positive, human epidermal growth factor receptor-2 negative (HR+/HER2-) advanced or metastatic breast cancer.

Kisqali is a CDK4/6 inhibitor approved based on a first-line phase III trial that met its primary endpoint early, demonstrating statistically significant improvement in progression-free survival (PFS) compared to letrozole alone at the first pre-planned interim analysis. Kisqali was reviewed and approved under the FDA Breakthrough Therapy designation and Priority Review programs.

"Kisqali is emblematic of the innovation that Novartis continues to bring forward for people with HR+/HER2- metastatic breast cancer," said Bruno Strigini, CEO, Novartis Oncology. "We at Novartis are proud of the comprehensive clinical program for Kisqali that has led to today's approval and the new hope this medicine represents for patients and their families."

The FDA approval is based on the superior efficacy and demonstrated safety of Kisqali plus letrozole versus letrozole alone in the pivotal Phase III MONALEESA-2 trial. The trial, which enrolled 668 postmenopausal women with HR+/HER2- advanced or metastatic breast cancer who received no prior systemic therapy for their advanced breast cancer, showed that Kisqali plus an aromatase inhibitor, letrozole, reduced the risk of progression or death by 44% over letrozole alone (median PFS not reached (95% CI: 19.3 months-not reached) vs. 14.7 months (95% CI: 13.0-16.5 months); HR=0.556 (95% CI: 0.429-0.720); p<0.0001).

More than half of patients taking Kisqali plus letrozole remained alive and progression free at the time of interim analysis, therefore median PFS could not be determined. At a subsequent analysis with additional 11-month follow-up and progression events, a median PFS of 25.3 months for Kisqali plus letrozole and 16.0 months for letrozole alone was observed. Overall survival data is not yet mature and will be available at a later date.

"In the MONALEESA-2 trial, ribociclib plus letrozole reduced the risk of disease progression or death by 44 percent over letrozole alone, and more than half of patients (53%) with measurable disease taking ribociclib plus letrozole experienced a tumor burden reduction of at least 30 percent. This is a significant result for women with this serious form of breast cancer," said Gabriel N. Hortobagyi, M.D., Professor of Medicine, Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center and MONALEESA-2 Principal Investigator. "These results affirm that combination therapy with a CDK4/6 inhibitor like ribociclib and an aromatase inhibitor should be a new standard of care for initial treatment of HR+ advanced breast cancer."

Kisqali is taken with or without food as a once-daily oral dose of 600mg (three 200mg tablets) for three weeks, followed by one week off treatment. Kisqali is taken in combination with four weeks of any aromatase inhibitor.