Kisqali prolonged PFS benefit for pre- and perimenopausal patients with aggressive HR+/HER2- metastatic breast cancer compared to chemotherapy

CT has remained the preferred option for patients with rapidly progressing disease and visceral crisis, despite the widespread adoption of CDK4/6 inhibitors (CDK4/6i) plus ET as first-line treatment for HR+/HER2- MBC. Kisqali demonstrated a nearly one-year progression-free survival (PFS) benefit in the study, supporting the superiority of Kisqali plus ET for this hard-to-treat patient population. RIGHT Choice is the first randomized study comparing a CDK4/6i plus ET vs. combination CT in aggressive HR+/HER2- MBC; data from this open-label, multi-national trial will be presented as a late-breaker oral presentation at the 2022 San Antonio Breast Cancer Symposium (SABCS) and included in the SABCS press program.

The study enrolled 222 patients with aggressive forms of HR+/HER2- MBC (i.e., with symptomatic visceral metastases, rapid disease progression or markedly symptomatic non-visceral metastases), including more than 50% of patients with visceral crisis as determined by investigators; Kisqali plus ET doubled the median PFS vs. combination CT at 24.0 months compared to 12.3 months (HR=0.54; 95% CI: 0.36-0.79; p=.0007) in the first-line setting. Median time to treatment failure with Kisqali plus ET was 18.6 months compared to 8.5 months with combination CT (HR=0.45; 95% CI: 0.32-0.63).

Furthermore, patients in the Kisqali plus ET arm of the trial reported lower rates of treatment-related serious adverse events (AEs) and lower rates of discontinuation due to treatment-related AEs, compared to patients in the combination CT trial arm. Overall, the Kisqali safety profile was consistent with previously reported data.

“Younger patients with aggressive disease often show resistance to treatment, resulting in worse prognoses – so it is encouraging to see RIGHT Choice data demonstrating a significant one-year benefit for this patient population when using ribociclib plus endocrine therapy compared to combination chemotherapy. Patients on the ribociclib arm had also lower rates of adverse events, such as diarrhea and fatigue, compared to chemotherapy, which could potentially impact quality of life,” said Dr. Yen-Shen Lu, Division Chief of Medical Oncology at Department of Oncology, National Taiwan University Hospital. “With these improvements in outcomes and tolerability, oncologists should consider ribociclib plus ET as a treatment option for patients with aggressive forms of HR+/HER2- MBC, including patients with visceral crisis.”

The study enrolled 222 patients with aggressive forms of HR+/HER2- MBC (i.e., with symptomatic visceral metastases, rapid disease progression or markedly symptomatic non-visceral metastases), including more than 50% of patients with visceral crisis as determined by investigators; Kisqali plus ET doubled the median PFS vs. combination CT at 24.0 months compared to 12.3 months (HR=0.54; 95% CI: 0.36-0.79; p=.0007) in the first-line setting. Median time to treatment failure with Kisqali plus ET was 18.6 months compared to 8.5 months with combination CT (HR=0.45; 95% CI: 0.32-0.63). Furthermore, patients in the Kisqali plus ET arm of the trial reported lower rates of treatment-related serious adverse events (AEs) and lower rates of discontinuation due to treatment-related AEs, compared to patients in the combination CT trial arm. Overall, the Kisqali safety profile was consistent with previously reported data1.