Background/Purpose: Every other week adalimumab is used to treat juvenile idiopathic arthritis (JIA) and other pediatric rheumatic diseases. It is common for pediatric rheumatologists to escalate to weekly dosing to achieve better disease control when needed. Weekly adalimumab has been demonstrated to be safe and effective in several autoimmune diseases in adults; however, to our knowledge, there have been no studies demonstrating the safety and effectiveness of weekly adalimumab in children with rheumatic diseases. We conducted a retrospective chart review of pediatric patients on weekly adalimumab to assess safety and clinical responsiveness.

Methods: Sixty-nine patients at the University of Minnesota or Gillette Children’s Hospital were identified as treated with weekly adalimumab. Sixty (87%) were eligible for the chart review. Demographic and clinical data were collected. Basic descriptive analysis was performed to assess for adverse events and clinical response to weekly adalimumab.

Results: Sixty-three percent (38/60) of patients on weekly adalimumab were females, and the mean age at initiation of weekly dosing was ~14 years. Weekly adalimumab was used most commonly to treat uveitis and rheumatoid factor-negative polyarticular JIA. Most of the patients were also on a nonsteroidal anti-inflammatory drug (NSAID) and methotrexate (Table 1). Only three patients (5%) had an infection requiring hospitalization. One patient with sepsis was concurrently taking an NSAID, methotrexate, and cyclosporine for treatment of chronic uveitis with JIA. Two patients (3%) developed autoimmune disease (Table 2). Most children dislike the pain associated with adalimumab injections, and, thus, the common practice at our clinics is to stop weekly dosing by three months if it is not helpful in treating the disease. Therefore, for this chart review, if the patient continued the weekly dosing for at least three months we determined they had a positive clinical response. Ninety-percent (53/59) of patients were determined to have a positive clinical response. One patient was lost to follow-up prior to the three month point.

Conclusion: The use of weekly adalimumab in children in our centers was determined to be safe and effective. Ninety-percent of patients had a positive clinical response. Minor infections were common, but serious infections requiring hospitalization were uncommon. Two patients on weekly adalimumab developed autoimmune disease. Adalimumab-induced autoimmunity is a recognized issue, but further studies are needed to determine if weekly dosing increases this risk in children.