Promising Rationally Derived Combination Therapy with PI3K and CDK4/6 Inhibitors

In this issue of Cancer Cell, Vora and colleagues demonstrate that persistent CDK4 and pRB activation underlie acquired resistance to phosphatidylinositol 3-kinase (PI3K) inhibitors in breast cancer cell lines, suggesting that clinical evaluation of rational combination therapy with PI3K and CDK4/6 inhibitors to mitigate resistance to PI3K inhibition is warranted