Generally, biomarkers could increase the success rate of medicinal product developments and as a consequence accelerate the availability of new therapeutics with an improved benefit–risk relationship. Therefore, patient identification based on predictive biomarkers is becoming increasingly important in all therapeutic areas [1]. The increasing use of predictive biomarker-guided-personalized (precision) medicine warrants the discovery of novel biomarkers as measurable indicators of physiopathological conditions [2]. Biomarkers can be used for diagnostics and prognostics, monitoring disease progression, but also to select the most effective therapy and to predict the treatment outcome [3, 4]. The current article provides a short focus on the regulatory definition of a biomarker and the biomarker qualification process of the European Medicines Agency (EMA). With the evolving landscape, the new Regulation (EU) 2017/746 on in vitro medical devices (IVDR) [5] introduces important changes in the EU legal framework for IVDs especially by legally defining for the first time “companion diagnostic” devices (CDx). Challenges in the codevelopment of CDx and medicinal products are highlighted to provide scientific–regulatory considerations in this complex regulatory field.
