The effect of CDK4/6 inhibitors on the overall survival in patients with advanced HR+/HER2- BC in the entire population and in special clinical subgroups of unfavorable prognosis: A review

Abstract

An increase in the median progression-free survival when using cyclin-dependent kinase 4/6 inhibitors in combination with aromatase inhibitors led to high expectations from the analysis of the overall survival of patients with HR+/HER2- metastatic breast cancer. Of the three drugs in the group, the final data were obtained in the MONALEESA-2 and PALOMA-2 studies, while a statistically significant difference in median overall survival was achieved only with the use of ribociclib. The review discusses possible factors that could affect the final results of the presented studies. The effect of ribociclib on the value of OS in clinically unfavorable prognostic subgroups (for example, patients with visceral metastases) and on progression-free survival depending on the expression of molecular genetic factors that worsen patient survival (such as Rb, p16, Ki-67, CDKN2A, CCND1, ESR1) was analyzed.The combination of ribociclib and aromatase inhibitors has proven to be an advantage in the treatment of patients with HR+/HER2- metastatic breast cancer in terms of increasing both progression-free survival and overall survival. Efficacy has been proven in subgroups with clinical and molecular adverse prognostic factors.