Novartis reports Phase 3 data on LEE011 in breast cancer
Novartis announced that results from the pivotal Phase III MONALEESA-2 study show LEE011, or ribociclib, plus letrozole significantly extended progression-free survival compared to a standard of care, letrozole, as a first-line treatment in postmenopausal women with hormone receptor positive, human epidermal growth factor receptor-2 negative advanced or metastatic breast cancer. The results demonstrate that LEE011 plus letrozole reduced the risk of death or progression by 44% over letrozole alone. The combination significantly improved PFS across all patient subgroups, regardless of disease characteristics or demographics. More than half of women with measurable disease taking LEE011 plus letrozole saw their tumor size shrink by at least 30% -- overall response rate in patients with measurable disease was 53% vs 37%. Most adverse events in the MONALEESA-2 trial were mild to moderate in severity, identified early through routine monitoring, and generally managed through dose interruption and reduction. The discontinuation rate due to adverse events in the MONALEESA-2 trial was 7.5% for LEE011 plus letrozole and 2.1% for letrozole alone. The most common grade 3/4 adverse events were as follows for LEE011 plus letrozole compared to letrozole alone: neutropenia 60% vs 1%, leukopenia 21% vs 1%, elevated alanine aminotransferase 9% vs 1%, lymphopenia 7% vs 1%, and elevated aspartate aminotransferase 6% vs 1%. Due to the significant extension of PFS and clinical benefit seen with LEE011, analysis of the primary endpoint in MONALEESA-2 was stopped early in May as recommended by the Independent Data Monitoring Committee. Follow up to measure overall survival is ongoing.