Biologic Agents Therapy for Saudi Children with Rheumatic Diseases: Indications and Safety

Objective: To report the indications and safety of biologic agents in childhood rheumatic diseases at a tertiary hospital.

Methods: Children with rheumatic diseases treated with biologic agents at King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia, from January 2001 to December 2011 were included. All patients were reviewed for: demographic characteristics, diagnosis, concomitant treatment and indications of using biologic agents, age at start of therapy and side effects during the treatment period.

Results: In all, 134 children (89 female) with various rheumatic diseases were treated with biologic agents. Mean age at starting biologic treatment was 9.3 (4.25-14) years and mean therapy duration was 14.7 (3-88) months. Juvenile idiopathic arthritis (JIA) was the most frequent diagnosis (70.1%) followed by systemic lupus erythematosus (12.7%) and vasculitis (4.5%). All patients received concomitant therapy (corticosteroids and disease-modifying antirheumatic drugs). In total, 273 treatments with biologic agents were used, (95 etanercept, 52 rituximab, 47 adalimumab, 37 infliximab, 23 anakinra, 10 tocilizumab and nine abatacept). Therapy was switched to another agent in 57 (42.5%) patients, mainly because of inefficacy (89.4%) or adverse event (10.6%). A total of 95 (34.8%) adverse events were notified; of these, the most frequent were infusion-related reactions (33.7%) followed by infections (24.2%) and autoantibody positivity (10.6%). One patient developed macrophage activation syndrome.

Conclusion: Biologic agents were used in children with a range of rheumatic diseases. Of these, the most frequent was JIA. Off-label use of biologic agents in our cohort is common. These agents seem safe. However, they may associated with various adverse events. Sequential therapy seems well tolerated. However, this should be carefully balanced and considered on an individual basis.