To obtain preliminary information about the safety and efficacy of intravenous immune globulin (IVIG: Iveegam, Immuno AG, Vienna) in the treatment of polyarticular juvenile rheumatoid arthritis (poly-JRA) resistant to other forms therapy.
We used a multicentered, phase I/II blinded-withdrawal design with stratified entry. All patients began by receiving open infusions of IVIG at a dose between 1.5 and 2.0 g/kg/infusion (100 g maximum) bimonthly for the first 2 months, then monthly for up to 6 months. Beginning at Month 3, those who met the criteria for "clinically important improvement" were randomized to receive monthly infusions for 4 months of either placebo or IVIG in a double blind (DB) phase. Patients were permitted nonsteroidal antiinflammatory drugs, slow acting antirheumatic drugs, and low dose (< 10 mg/day) prednisone at constant doses. An "early escape" provision in the DB allowed those who showed "clinically important worsening" to again receive IVIG (if taking placebo) or a higher dose of IVIG (if taking the lower dose of IVIG).
Efficacy. Twenty-five children entered the trial and 19 (76%) met the criteria for "clinically important improvement" during the open phase (OP) and entered the DB. Three patients completed the OP but failed to meet the criteria for response, and 3 patients dropped out of the OP, none of whom showed benefit from IVIG. Treatment effect sizes produced by IVIG were moderate to large for all variables in the OP. Patients who continued IVIG in the DB continued to show improvement over that achieved in the OP. Those given placebo showed a rapid loss of efficacy, suggesting IVIG has a limited duration of effect after discontinuation. Safety. No patient developed serious or unexpected adverse side effects in the open or DB phases, and none dropped out of the study due to toxicity or side effects.
Substantial clinical improvement from IVIG is produced in about three-fourths of patients with poly-JRA during open administration, but the duration of the beneficial effect is short after discontinuation. Those with disease < 3 years' duration may be more likely to respond than those who have had their disease for > 5 years. Short term safety is excellent.