Ribociclib Added to Endocrine Therapy Improved Disease-Free Survival Among Patients With HR-Positive, HER2-Negative Early Breast Cancer
According to interim results from an international phase 3 trial, ribociclib plus a nonsteroidal aromatase inhibitor significantly improved disease-free survival (DFS) among patients with hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER2)-negative early breast cancer.
“Ribociclib has been shown to have a significant overall survival benefit in patients with HR-positive, HER2-negative advanced breast cancer,” stated Dennis Slamon, MD, PhD, University of California, Los Angeles, and coauthors. “Whether this benefit in advanced breast cancer extends to early breast cancer is unclear.”
In this open-label trial, 5101 patients with stage II or III HR-positive, HER2-negative breast cancer were randomized on a 1-to-1 basis to receive 400 mg of ribociclib (daily for 3 weeks followed by 1 week off for a duration of 3 years) plus a nonsteroidal aromatase inhibitor (either 2.5 mg of letrozole, or 1 mg of anastrozole daily for ≥ 5 years), or either nonsteroidal aromatase inhibitor alone. Premenopausal patients additionally received goserelin every 28 days. The primary end point was invasive DFS. Secondary end points included distant DFS, recurrence-free survival (RFS), and safety.
At a follow-up of 3 years, invasive DFS was 90.4% in the ribociclib arm and 97.1% in the nonsteroidal aromatase inhibitor alone arm (hazard ratio [HR], 0.75; 95% confidence interval [CI], 0.62 to 0.91; P = .003). Distant DFS and RFS results also favored the ribociclib arm. No additional safety signals were identified.
Dr Slamon et al concluded, “Among patients with stage II or III HR-positive, HER2-negative early breast cancer, the addition of ribociclib to adjuvant endocrine therapy significant improved 3-year invasive disease-free survival.”
Source:
Slamon D, Lipatov O, Nowecki Z, et al. Ribociclib plus endocrine therapy in early breast cancer. N Engl J Med. Published online: March 20, 2024. doi:10.1056/NEJMoa2305488
