Can Improved Use of Biomarkers Alter the Fate of PI3K Pathway Inhibitors in the Clinic?

The high frequency of PI3K pathway alterations in cancer has motivated numerous efforts to develop drugs targeting this network. Although many potent and selective inhibitors have been developed and evaluated in preclinical models, their progress to clinical approval has been limited. Here we discuss the pressing need to develop improved biomarker strategies to guide patient selection and improve assessment of patient responses to PI3K pathway inhibitors to address unresolved issues surrounding the efficacy and tolerability of these compounds in patients with cancer. ©2021 American Association for Cancer Research.