Three inhibitors of CDK4/6 kinases were recently FDA approved for use in combination with endocrine therapy, and they significantly increase the progression-free survival of patients with advanced Estrogen Receptor positive (ER+) breast cancer in the first-line treatment setting.
A recent phase III trial has shown that fulvestrant combined with a CDK 4/6 inhibitor doubles PFS in aromatase inhibitor-pretreated postmenopausal ER+ breast cancer.
Inhibition of the p16INK4a/cyclin D/CDK4/6/RB pathway is an effective therapeutic strategy for the treatment of estrogen receptor positive (ER+) breast cancer.
Future trials evaluating further combination strategies with CDK 4/6 backbone and translational studies refining predictive biomarkers are needed to help personalize the optimal treatment regimen for individual patients with ER+ breast cancer.