CDK4/6 Inhibitor Biomarker Research: Are We Barking Up the Wrong Tree?

CDK4/6 inhibitors have emerged as a significant advance for the treatment of patients with advanced estrogen receptor-positive breast cancer. However, the identification of predictive markers that optimize their use is proving harder than expected. In this commentary we advocate for unbiased discovery and a collaborative approach across trials.See related article by Finn et al., p. 110. ©2019 American Association for Cancer Research.