First-line ribociclib plus letrozole in postmenopausal women with HR+ , HER2− advanced breast cancer: Tumor response and pain reduction in the phase 3 MONALEESA-2 trial

Purpose The phase 3 MONALEESA-2 study demonstrated that addition of ribociclib (RIB) to letrozole (LET) significantly improved progression-free survival (PFS) in patients (pts) with hormone receptor-positive (HR+), HER2-negative (HER2−) advanced breast cancer (ABC). Here, we evaluated duration of response (DoR), tumor shrinkage, PFS by treatment-free interval (TFI), and health-related quality of life (HRQoL).