Phase III MONALEESA-2 study reinforces efficacy and safety of Kisqali (ribociclib) plus letrozole in HR+/HER2- advanced or metastatic breast cancer- Novartis

Novartis announced updated findings from the Phase III MONALEESA-2 study that reinforce the efficacy and safety of Kisqali (ribociclib) plus letrozole in postmenopausal women with hormone receptor positive, human epidermal growth factor receptor-2 negative (HR+/HER2-) advanced or metastatic breast cancer. After an additional 11 months of follow-up, a median progression-free survival (PFS) of 25.3 months for Kisqali plus letrozole and 16.0 months for letrozole alone was observed. These updated results further support that Kisqali plus letrozole improves PFS as a first-line treatment across all patient subgroups.

After two years of treatment, the progression-free survival rate was 54.7% in the Kisqali plus letrozole arm compared to 35.9% in patients treated with letrozole alone. In a cohort of 213 US patients treated as part of MONALEESA-2, the median PFS was 27.6 months with Kisqali plus letrozole and 15.0 months with letrozole alone.

Treatment benefit remained consistent across all patient subgroups regardless of demographics or disease characteristics, including women with visceral disease and those diagnosed de novo. In women with measurable disease at baseline, 55% saw their tumor size shrink by at least 30% (overall response rate (ORR)) compared to 39% with letrozole plus placebo1. Follow-up to measure overall survival is ongoing as data remain immature. These data will be presented at the 53rd Annual Meeting of the American Society of Clinical Oncology.