EULAR Study Group: Therapeutic Drug Monitoring of Biopharmaceuticals in Rheumatology Aim of the study group To understand the required clinical and economic evidence to support the introduction of Therapeutic Drug Monitoring (TDM) of biopharmaceuticals in daily rheumatology practice of inflammatory arthritis. Background TDM of biopharmaceuticals refers to the principle of using serum biopharmaceutical levels and, optionally, anti-drug antibodies (ADA), to guide patient dosing. TDM has the potential to personalise dosing, avoiding over- and under-treatment, which could result in safer and more effective use of health care resources. The number of publications on TDM of biopharmaceuticals is increasing, alongside a growing awareness and interest in TDM among rheumatologists. Validated assays for TDM, both for measuring drug levels and ADA, are becoming widely available alongside a steady reduction in their costs. To date, however, there have been limited high quality clinical or economic evaluations of TDM and little guidance exists on if or how to use TDM in clinical practice. Who we are Our group draws on expertise from across Europe, including Centres that have published widely in this field. Currently approximately 40 members from Finland, France, Israel, the Netherlands, Norway, Slovenia, Spain, and the UK are included. Mission Setting the relevant research agenda, including cost-effectiveness of TDM Development of best practice guidelines Physician education. Many rheumatologists are unaware of the pharmacokinetic (PK) properties of biopharmaceuticals and are agnostic as to whether TDM-informed dosing may improve outcomes. Exploration of patient views around TDM. Understanding whether TDM would improve ownership of patient health decisions and improve patient education. Activities to date EULAR 2018 Amsterdam, first meeting preparing the Study Group application ACR 2018 Chicago, informal meeting to plan the December meeting in Amsterdam December 2018 Amsterdam, preparing application to becoming a Task Force, update relevant local activities, attendance 2nd TDM symposium March 2019 approval of Task Force designation Contact: John Isaacs, john.isaacs@ncl.ac.uk Professor of Clinical Rheumatology and Director of Therapeutics, Newcastle University. 13/03/2019