CDK4 and breast carcinoma: A pooled analysis of 7 phase 3 trials in patients with HR+/HER2− advanced breast cancer receiving first-line CDK4/6i (N=1111) demonstrated that CDK4/6i plus ET provided greater PFS benefit compared with placebo plus ET in patients with visceral metastasis, with a hazard ratio similar to those in the broader intended-use population (22).