Ribociclib Plus Endocrine Therapy in Hormone Receptor-Positive/ERBB2-Negative Early Breast Cancer: 4-Year Outcomes...

Area of Science:

• Oncology
• Clinical Trials
• Pharmacology

Background:

• Hormone receptor-positive/ERBB2-negative early breast cancer remains a significant health concern.
• Adjuvant therapy aims to reduce recurrence risk after primary treatment.
• Ribociclib (LEE011) plus a nonsteroidal aromatase inhibitor (NSAI) showed a disease-free survival benefit in the NATALEE trial.

Purpose of the Study:

• To evaluate the long-term efficacy and safety of adjuvant ribociclib plus NSAI versus NSAI alone.
• To assess invasive disease-free survival (iDFS) beyond the planned 3-year treatment period.
• To analyze the sustained impact of ribociclib on recurrence rates in early breast cancer.

Main Methods:

• Exploratory analysis of the international, open-label, randomized phase 3 NATALEE trial.
• Patients received either ribociclib (36 months) plus NSAI (60 months) or NSAI alone.
• Primary endpoint: iDFS. Secondary endpoints: distant disease-free survival, recurrence-free survival, overall survival. Kaplan-Meier method used for survival evaluation.

Main Results:

• Median follow-up of 44.2 months in 5101 patients.
• Ribociclib plus NSAI demonstrated a continued iDFS benefit (HR, 0.72).
• 4-year iDFS rates were 88.5% for ribociclib + NSAI vs. 83.6% for NSAI alone, showing a 4.9 percentage point difference.

Conclusions:

• Adjuvant ribociclib plus NSAI provides a consistent and sustained iDFS benefit in hormone receptor-positive/ERBB2-negative early breast cancer.
• The efficacy observed extends beyond the 3-year treatment duration.
• These findings support the long-term value of combining ribociclib with NSAI for adjuvant therapy in this patient population.