Combination therapy with steroids and mizoribine in juvenile SLE: a randomized controlled trial

The initial treatment of childhood-onset systemic lupus erythematosus (SLE) is not standardized. Although corticosteroids are the first-line therapy for SLE, long-term, high-dose steroid therapy is associated with various side effects in children. The Japanese Study Group for Renal Disease in Children (JSRDC) has carried out a multi-center, randomized, controlled trial to evaluate the efficacy and safety of corticosteroid and mizoribine (MZB) therapy as an initial treatment for newly diagnosed juvenile SLE. Twenty-eight patients were treated with a combination steroid and MZB (4-5 mg/kg/day) (group S+M) drug therapeutic regimen, while 29 patients were treated with steroid only (group S); both groups were followed up for 1 year. The time to the first flare from treatment initiation was not significantly different between the two groups (Kaplan-Meier method, p = 0.09). During the period when the steroid was given daily (day 0-183), the time to the first flare from treatment initiation was significantly longer in the patients of group S+M than in those of group S (log-rank test, p = 0.02). At the end of the study period, there were no differences in the severity of proteinuria and renal function impairment between the two groups. No patients dropped out of the trial due to adverse events. In conclusion, our combined steroid and MZB drug therapeutic regimen was not shown to be significantly better than the steroid-only therapy as initial treatment for juvenile SLE. Whether MZB administered in a higher dose would be therapeutically advantageous can only be answered by further studies.