gms | German Medical Science

Biomarkers are of increasing importance for personalized medicine, including diagnosis, prognosis, and targeted therapy of a patient. Their use is extremely diverse, and it varies from pharmacodynamics to treatment monitoring. The particular features of DNA biomarkers, such as single nucleotide polymorphisms are discussed. Examples are provided for current use of DNA biomarkers in applications. Before a DNA biomarker or a set of DNA biomarkers is used in clinical routine for diagnosis, several phases of research need to be successfully passed. The phases for clinical trials for the validation of diagnostic and prognostic biomarkers are discussed in detail. Some DNA biomarkers and other biomarkers, such as DNA tumor biomarkers, are additionally intended to predict the likely response of a patient to a treatment in terms of efficacy and/or safety, and these are termed predictive biomarkers or, more generally, companion diagnostic tests. The final part of this article considers one specific clinical trial design for these biomarkers in detail.