The current landscape of the FDA approved companion diagnostics.

Predictive biomarker is an important element in the realization of precision medicine and with the introduction of the drug-diagnostic codevelopment model, the number of regulatory approved companion diagnostics (CDx) have steadily increased. This short perspective is based on an analysis of the FDA List of Cleared or Approved Companion Diagnostic Devices and focus on the biomarkers, drugs, clinical indications, analytical platforms, regulatory paths and status related to the different assays. By the end of 2020, the total number of CDx assays approved by the FDA had reached 44. These assays are almost exclusively linked to different hematological and oncological drugs. Without an accurate and reliable CDx assay these drugs will lose their value. The analytical platforms are diverse and cover technologies like immunohistochemistry, in situ hybridization, polymerase chain reaction, next generation sequencing, and imaging. CDx assays are high risk devices and the regulatory path almost exclusively requires submission of a Premarket Application (PMA); however, a relatively large group of the CDx assays is PMA approved Laboratory Developed Test.