Challenges in the clinical implementation of precision medicine companion diagnostics.

Introduction: The pace of biomarker discovery has increased exponentially over the last few years, ushering in an era of precision medicine (PM) with a growing arsenal of treatments tailored to specific patient populations. To accurately identify patients, companion diagnostics (CDx) are developed and launched alongside these treatments. However, even with a timely launch of therapies and CDx tests, patients are not guaranteed optimal access to these tests because of the inefficiencies embedded within the clinical diagnostic testing landscape supporting PM.