An open label study to establish dosing recommendations for nabumetone in juvenile rheumatoid arthritis

Once-a-day dosing with nabumetone has been shown to be effective in adults with rheumatoid arthritis. We establish dosing recommendations for nabumetone in children and adolescents with juvenile rheumatoid arthritis (JRA).

An open label, multicenter study was conducted in children with JRA aged 2-16 years, weighing > 14 kg, and requiring nonsteroidal antiinflammatory drugs (NSAID) for control of symptoms. NSAID were discontinued one day prior to study initiation to minimize disease flare. Patients received nabumetone 30 mg/kg once daily (as a tablet or a slurry) for 12 weeks. Efficacy assessment evaluations were performed at Weeks 1, 3, 6, and 12, based on the mean change from baseline at the study endpoint for 6 standard rheumatology variables. An overall assessment of efficacy was determined based on the percentage of patients who did not experience a flare, using the 6 rheumatology variables. Since this was an open label study, only descriptive statistics were obtained for efficacy variables. Routine safety assessments were completed for all patients.

In total, 99 patients with JRA were enrolled and 89 completed the study; mean age was 9.2 years. The proportion of nabumetone treated patients with no flare in disease activity during the nabumetone treatment period was 92/99 (93%). Improvement was noted in each efficacy assessment, although statistical evaluations were not performed. The adverse event profile was similar to that reported for nabumetone in adults with RA.

Nabumetone 30 mg/kg/day (up to 2000 mg/day) demonstrated a safe profile with no loss of efficacy compared to previous treatment in children with JRA. The dose can be administered by suspending tablets in warm water to create a slurry.