Dr El-Saghir on the Implications of the RIGHT Choice Trial of Ribociclib Plus ET in HR+, HER2– Advanced Breast Cancer

“[Data from] this study lay to rest the idea that patients with visceral metastases [who are] endocrine responsive with ER-positive, HER2-negative disease need chemotherapy. We can give those patients endocrine therapy plus a CDK4/6 inhibitor, and in our study we used ribociclib.”

Nagi S. El-Saghir, MD, FACP, FASCO, a professor of clinical medicine, head of the Division of Hematology Oncology, Department of Internal Medicine, and director of the Breast Center of Excellence at the American, Naef K Basile Cancer Institute, University of Beirut Medical Center, discussed the clinical implications of the phase 2 RIGHT Choice trial (NCT03839823).

RIGHT Choice examined frontline treatment with ribociclib (Kisqali) in combination with endocrine therapy (ET) vs combination chemotherapy in patients with clinically aggressive hormone receptor (HR)–positive, HER2-negative advanced breast cancer. During 2025 ASCO Annual Meeting, El-Saghir presented findings from a subgroup analysis which evaluated the regimen’s activity in patients with or without liver metastases.

Data from the subgroup analysis showed that patients with liver metastases in the ribociclib arm (n = 54) experienced 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) in the chemotherapy arm (n = 53; HR, 0.68; 95% CI, 0.42-1.11). Among patients without liver metastases, the median PFS in the investigational and control arms was 25.2 months (95% CI, 18.6-not evaluable) and 15.4 months (95% CI, 8.8-20.0), respectively (HR, 0.57; 95% CI, 0.34-0.93).

These data show that the approach used in RIGHT Choice is superior to combination chemotherapy in terms of efficacy, without many of the toxicities of chemotherapy, El-Saghir said. Notably, the safety profile of ET plus ribociclib, including liver-related safety signals, was similar between patients with and without liver metastases. Patient quality of life benefits vs chemotherapy were also reported in both subgroups.

These data should close the door on the notion that combination chemotherapy should be used in most patients in this population, El-Saghir added. Patients with HR-positive, HER2-negative advanced endocrine-sensitive breast cancer should be treated with ET in combination with a CDK4/6 inhibitor such as ribociclib, he concluded.