RecruitingPhase 4Drug trialEffect of Proactive Therapeutic Drug Monitoring on Maintenance of Sustained Disease Control in Adults With Rheumatoid Arthritis on a Subcutaneous TNF Inhibitor: The Rheumatoid Arthritis Therapeutic DRUg Monitoring Trial (RA-DRUM)The goal of this clinical trial is to compare therapeutic drug monitoring (TDM) versus Standard of care in patients with rheumatoid arthritis treated with a subcutaneous tumor necrosis factor inhibitor (adalimumab). The main question it aims to answer is: Is TDM superior to standard of care in order to maintain sustained disease control without flares? Participants will be followed with blood sampling every second month, measuring serum drug levels and anti-drug antibodies of the TNFi. In the TDM-group, the researchers will adjust the dosage of the TNFi based on knowledge on optimal therapeutic ranges. In the Standard of care group, the TNFi will be administered according to standard of care without knowledge of serum drug levels or anti-drug antibodies.