Rheumatoid arthritis (RA) is a chronic inflammatory disease affecting joints and causing progressive disability. Current treatment strategies involve conventional disease-modifying anti-rheumatic drugs (csDMARDs) and, in more resistant cases, biologic DMARDs (bDMARDs) such as Rituximab. Rituximab, a monoclonal antibody targeting CD20-positive B cells, is administered as an induction dose followed by maintenance therapy every six months. Standard maintenance dosing consists of 1g infusions, but lower doses may provide equivalent efficacy with fewer side effects.
The RADAR trial is a multicenter, prospective, randomized, double-blinded, non-inferiority controlled trial designed to evaluate whether a 200 mg maintenance dose of Rituximab every six months is non-inferior to the standard 1g dose in patients with RA who are in low disease activity. The study will assess disease activity using the DAS28-CRP score over 12 months, alongside various secondary endpoints, including treatment failure rates, immune responses, and adverse events.
By determining the minimum effective Rituximab dose, the study aims to optimize patient safety, reduce the risk of infections, and lower healthcare costs. This trial is particularly relevant as Rituximab has lost patent protection, making cost-effective treatment crucial, especially in low-resource settings. Findings from this study could lead to updated treatment guidelines, benefiting RA patients worldwide.
Age ≥ 18 years
Diagnosis of rheumatoid arthritis (RA) according to EULAR/ACR 2010 classification criteria
DAS28 ≤ 5.1
Current maintenance treatment with Rituximab regardless of dose and/or duration of Rituximab treatment and with at least first cycle of Rituximab ended (2 initial infusions)
Rheumatic autoimmune disease other than RA (except associated Sjogren's disease, which is allowed)
Concurrent treatment with any other targeted therapy than Rituximab
Any contraindication to Rituximab or to NaCl 0.9%
Significant uncontrolled associated disease or comorbidity