HR and breast carcinoma: In patients with low disease burden, dose interruptions and reductions for ribociclib (in the ribociclib + letrozole group) were required in 153 (77.7%) and 109 (55.3%) patients, respectively; for placebo (in the placebo + letrozole group), dose interruptions and reductions were required in 79 (40.3%) and 12 (6.1%) patients, respectively (Burris HA et al. First-line ribociclib + letrozole in patients with HR+/HER2– advanced breast cancer presenting with visceral metastases or bone-only disease: a subgroup analysis of the MONALEESA-2 trial.