Adding Ribociclib to Standard Hormone Therapy in Early-Stage Breast Cancer: NATALEE Update

By: Joshua D. Madera, MD
Posted: Friday, January 19, 2024

The addition of the CDK4/6 inhibitor ribociclib to the standard-of-care nonsteroidal aromatase inhibitor (NSAI) for the treatment of hormone receptor–positive, HER2-negative early-stage breast cancer significantly improved the rates of invasive disease–free survival compared with NSAI treatment alone, according to the results of the phase III NATALEE trial, presented at the 2023 San Antonio Breast Cancer Symposium (Abstract GS03-03). The treatment-related adverse events associated with the recommended starting dose of adjuvant ribociclib were considered to be safe and manageable, explained Gabriel Hortobagyi, MD, FACP, of The University of Texas MD Anderson Cancer Center, Houston, and colleagues.

“[NATALEE] shows the continued disease-free survival improvement for patients receiving ribociclib with hormone therapy and showed a benefit across clinically relevant subgroups,” stated Dr. Hortobagyi.

A total of 5,101 patients with either anatomic stage IIA, IIB, or III breast cancer, as determined by the American Joint Committee on Cancer guidelines, were recruited for the study. Patients were randomly assigned to receive ribociclib plus NSAI or NSAI alone. Patients remained eligible for involvement in the study as long as they continued to receive NSAI therapy and were followed regularly to assess their clinical outcomes.

The study authors reported invasive disease–free survival events in 8.9% of patients receiving the combination therapy and 11.1% of those receiving NSAI alone. The rates of invasive disease–free survival events at the 3-year evaluation period were 90.7% and 87.6% for patients receiving ribociclib and NSAI and NSAI alone, respectively. Furthermore, the rates of distant disease–free survival and recurrence-free survival were improved in patients receiving the combination regimen vs NSAI alone.

Disclosure: The study was sponsored by Novartis Pharmaceuticals, which markets ribociclib. Dr. Hortobagyi is a paid consultant for Novartis, and MD Anderson received funds from Novartis to conduct this study.

2023 San Antonio Breast Cancer Symposium

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