To evaluate whether stringent follow-up consisting of combined laboratory and ultrasound surveillance is superior to clinical monitoring alone to maintain clinical remission in rheumatoid arthritis.

Randomized, controlled, parallel-group, multi-centre study in which patients with rheumatoid arthritis treated with biological/targeted synthetic disease modifying antirheumatic drug (b/tsDMARD) in mono- or combination therapy with conventional synthetic disease modifying antirheumatic drug (csDMARD) in a stable dosage and interval for ≥6 months with low disease activity or remission will receive an power Doppler musculoskeletal ultrasound examination (PDUS) and monitoring of C-reactive protein (CRP) levels at baseline and several timepoints within a 24 month study period (primary endpoint) and within a 48 month long-term extension. At baseline, b/tsDMARD medication will be withdrawn in all patients, who will be randomized in a 1:1 ratio in an "Assisted monitoring" (arm A) or a "Clinical monitoring" (arm B) arm respectively. Further stratification for remission vs. low disease activity and mono- vs combination therapy will be implemented in the randomisation process. In arm A, CRP and PDUS information will be made available to the clinical assessors who, at each time-point will use this information along with that from clinical examination, to identify patients experiencing recurrence of inflammation which will then be counted as subclinical flare according to predefined criteria. In arm B the results of CRP and PDUS will be recorded but will not be made available to the clinical assessor who will have to identify clinical flares according to predefined criteria based on information from the clinical examination only.

Inclusion Criteria:

Patients with rheumatoid arthritis classified by the American College of Rheumatology/European League Against Rheumatism classification criteria

• biological disease-modifying anti-rheumatic drug (bDMARD) or targeted synthetic disease-modifying anti-rheumatic drug (tsDMARD) treatment in monotherapy or in combination therapy with conventional synthetic disease-modifying anti-rheumatic drug (csDMARD) in a stable dosage and interval for ≥6 months. Previous extension of bDMARD or tsDMARD interval will also be accepted. bDMARDs and tsDMARDs will include all currently available originator and biosimilar compounds, with the exception of rituximab and its biosimilar compounds
• No swollen joint by 28-joint count at baseline, and screening
• C-reactive protein of ≤0.5mg/dL at baseline AND history of C-reactive protein >0,5mg/dl related to rheumatoid arthritis activity
• Clinical disease activity index ≤10
• Shared decision between patient and physician to attempt b/tsDMARD withdrawal
• Willing and able to understand and follow the study procedures
• Written informed consent
• Female and male subjects aged ≥ 18 years

Exclusion Criteria:

• History of or current extra-articular manifestation of rheumatoid arthritis, with exception of rheumatoid nodules
• Systemic glucocorticoid treatment in the past 3 months
• Intraarticular injection with glucocorticoids in the past 1 month
• Joint replacement surgery other than total knee or hip arthroplasty or complete joint destruction
• Power Doppler signal ≥2 in any assessed joint and/or tendon at screening or baseline

After checking the inclusion- and exclusion criteria and after the patients´ consent the study investigator contacts the administrative office of the coordinating center. The online computerised randomisation algorithm "Randomizer for Clinical Trials by the Medical University of Vienna (MUW) will be used for randomisation for all centres.