Abstract
Companion diagnostics (CDx), which is essential in precision medicine, is changing to a personalized treatment approach. CDx is a test that identifies patients who can benefit from a specific drug and those who experience side effects of drugs for safe and effective treatment. Conversely, when CDx has inadequate diagnostic performance or has not been adequately validated in a particular treatment, treatment prediction based on diagnostic results is not possible. Given the importance of CDx for the clinical use of biomarkers, strict regulation is essential. Regulators are providing more stringent regulations and are developing or revising guidelines. For example, the EU's In Vitro Diagnostic Regulation has defined CDx for the first time, raising awareness of the importance of CDx. However, if a new clinical performance test needs to be performed to meet the latest specifications or requirements for clinical data, problems such as securing clinical samples or institutions, cost, and time may occur. Therefore, an efficient clinical regulatory process may be required to meet stringent regulatory requirements. This study examines the need to strengthen the current clinical regulatory framework for CDx through an institutional comparison of regulatory agencies (FDA, EMA, and MFDS).