Novartis' Kisqali Demonstrates Sustained Benefit in 5-Year Breast Cancer Trial.

Novartis has released results from the five-year analysis of the Phase 3 NATALEE trial of Kisqali (ribociclib) for high-risk stage II and III hormone receptor-positive/human epidermal growth factor receptor 2-negative early breast cancer. The data demonstrated a sustained benefit at a median of two years after a three-year treatment with Kisqali, with a 28.4% reduction in risk of recurrence and a 4.5% improvement in invasive disease-free survival rates. Overall survival continues to show an encouraging trend, with a 20% reduction in the risk of death compared to endocrine therapy alone.

Novartis AG (NYSE: NVS) has released five-year results from the Phase 3 NATALEE trial of Kisqali (ribociclib), demonstrating sustained benefits for high-risk stage II and III hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) early breast cancer patients. The data, presented at the European Society for Medical Oncology (ESMO) Congress 2025, showed a 28.4% reduction in risk of recurrence and a 4.5% improvement in invasive disease-free survival (iDFS) rates .

The trial, which enrolled 5,101 patients across 20 countries, found that the five-year iDFS rates were 85.5% in the Kisqali plus endocrine therapy (ET) arm versus 81.0% in the ET alone arm. This represents a clinically meaningful improvement. Additionally, overall survival (OS) showed a 20% reduction in the risk of death compared to ET alone, with a hazard ratio (HR) of 0.800 and a narrowing confidence interval (CI) .

The trial will continue follow-up to ensure sufficient data is collected for OS and other long-term endpoints. The results were presented by Dr. John Crown, a consultant medical oncologist at St. Vincent's University Hospital, Dublin, and NATALEE investigator, who noted the significance of the findings for patients and their families.

Novartis' Global Head of Oncology and Hematology Development, Dushen Chetty, highlighted the robustness of the observed iDFS benefit across clinically relevant subgroups. "These data reinforce the potential of Kisqali to significantly reduce the long-term risk of breast cancer recurrence, extending well beyond the three-year treatment period," he said.

Kisqali remains the only CDK4/6 inhibitor to demonstrate statistically significant OS benefits across three randomized controlled trials in advanced breast cancer (MONALEESA-2, MONALEESA-3, and MONALEESA-7) . The drug has achieved the highest score (A) on the European Society for Medical Oncology-Magnitude of Clinical Benefit Scale (ESMO-MCBS) for early breast cancer (EBC) and has the highest rating of any CDK4/6 inhibitor on the ESMO Magnitude of Clinical Benefit Scale for first-line pre-menopausal patients with HR+/HER2- advanced breast cancer .

The NATALEE trial is a global Phase III multi-center, randomized, open-label study evaluating the efficacy and safety of Kisqali with ET as an adjuvant treatment versus ET alone in the broadest range of patients with stage II and III HR+/HER2- EBC. The primary endpoint of NATALEE is invasive disease-free survival (iDFS) as defined by the Standardized Definitions for Efficacy End Points (STEEP) criteria .