Janni W, et al. - Duration of response (DoR), tumor shrinkage, progression-free survival (PFS) by treatment-free interval (TFI), and health-related quality of life (HRQoL) were assessed in postmenopausal women treated with ribociclib (RIB) + letrozole (LET) for hormone receptor-positive (HR+), HER2-negative (HER2-) advanced breast cancer (ABC) in the phase 3 MONALEESA-2 study. RIB + LET versus placebo + LET was shown to be associated with an earlier and more durable tumor response, greater degree of tumor shrinkage and pain reduction, and PFS benefit independent of TFI. Overall, RIB plus LET was supported as a first-line treatment option for postmenopausal women with HR+ , HER2- ABC.