49 patients received abemaciclib, 83 palbociclib and 43 ribociclib. 49 patients were HER2 0+, 57 HER2 1+ and 69 HER2 2+. Key clinical and treatment characteristics are shown. Overall PFS was 35.61 months (95% CI 25.46 - 45.76). PFS was 21.52 months (95% CI: 14.30 - 28.73), 31.15 months (95% CI: 15.59 - 46.70) and 39.49 months (95% CI: not estimable) in the HER2 0+, 1+ and 2+ population, respectively...In our cohort of patients with luminal phenotype breast cancer treated with CDK4/6 inhibitors, HER2 low expression was associated with a trend toward longer PFS...