Dr Saghir on Ribociclib Plus Endocrine Therapy in Premenopausal HR+/HER2-Negative Advanced Breast Cancer

“We conclude that patients with visceral disease, [including] symptomatic liver metastases, do better with the combination of ribociclib plus endocrine therapy and ovarian function suppression vs combination chemotherapy, and ribociclib plus endocrine therapy is a [treatment] option for those patients."

Nagi S. El-Saghir, MD, FACP, FASCO, a professor of clinical medicine and director of the Breast Center of Excellence at the American University of Beirut Medical Center, discussed subgroup findings from the phase 2 RIGHT Choice trial (NCT03839823), which evaluated ribociclib in combination with endocrine therapy vs combination chemotherapy in premenopausal patients with hormone receptor–positive, HER2-negative advanced breast cancer.

This subgroup analysis, which was presented at the 2025 ASCO Annual Meeting, focused on patients with and without liver metastases. Among those with liver metastases, ribociclib plus endocrine therapy (n = 54) produced a median progression-free survival (PFS) of 18.3 months (95% CI, 10.3-24.0) compared with 12.7 months (95% CI, 7.5-21.0) for chemotherapy (n = 53; HR, 0.68; 95% CI, 0.42-1.11). In patients without liver metastases, those given ribociclib plus endocrine therapy (n = 58) achieved a median PFS of 25.2 months (95% CI, 18.6-not evaluable) compared with 15.4 months (95% CI, 8,8-20.0) for chemotherapy (n = 57; HR, 0.57; 95% CI, 0.34-0.93).

El-Saghir noted that these data provide important insights for the treatment of patients with aggressive disease characteristics, particularly those with symptomatic visceral metastases, who have historically been underrepresented in pivotal CDK4/6 inhibitor trials. He noted that patients receiving ribociclib plus endocrine therapy in RIGHT Choice derived not only greater clinical efficacy but also improved quality-of-life outcomes.

According to El-Saghir, these findings support the use of ribociclib plus endocrine therapy as a frontline treatment option in hormone receptor–positive, HER2-negative advanced breast cancer, including for patients with liver metastases, offering a clinically effective, less toxic alternative to chemotherapy that may enhance disease control and patient-reported outcomes in this high-risk subgroup.