293PD_PRRibociclib (RIBO) + letrozole (LET) in male patients (pts) with hormone receptor-positive (HR+), human epidermal growth factor receptor-2–negative (HER2–) advanced breast cancer (ABC) and no prior endocrine therapy (ET) for ABC: Preliminary subgroup results from the phase IIIb CompLEEment-1 trial. (23rd October 2018)