Approaches to Integrating Biomarkers into Clinical Trials and Care Pathways as Targets for Treatment of Inflammatory Bowel Diseases

Abstract Background & Aims There is no consensus on the best way to integrate biomarkers into inflammatory bowel disease (IBD) research and clinical practice. The International Organization for the Study of Inflammatory Bowel Disease (IOIBD) aimed to outline biomarker definitions, categories, and operating properties required for their use in registration trials and clinical practice. Using fecal calprotectin as an example, we provide a framework for biomarker development and validation in patients with IBD. Methods We reviewed international society guidelines, regulatory agency guidance documents, and standardized reporting guidelines for biomarkers, in combination with publications on fecal calprotectin levels in patients with IBD. We assessed the validity of fecal calprotectin to serve as a surrogate biomarker of IBD activity and outlined a framework for further validation and development of biomarkers. Results No endpoints have been fully validated as surrogates of risk of disease complications—mucosal healing is the most valid endpoint used to determine risk of disease complications. Fecal level of calprotectin has not been validated as a biomarker for IBD activity, due to lack of technical and clinical reliability, assessment of performance when used as a replacement for endoscopy, and assessment of responsiveness to changes in disease states. The level of fecal calprotectin can be used only as a prognostic factor for disease recurrence in patients in remission following medical or surgical treatment. Conclusions We reviewed guidelines, regulatory documents, and publications to identify properties required for development of biomarkers of IBD activity and areas in need of clarification from regulatory agencies and societies. We propose a path forward for research of biomarkers for IBD.