Intravenous immunoglobulin in relapsing-remitting multiple sclerosis: A dose-finding trial

Objective: Several studies have reported a reduction of relapses after the long-term administration of IV immunoglobulin (IVIG) to patients with relapsing-remitting multiple sclerosis (RRMS), but they were mostly small and differed in terms of predefined outcome variables and treatment regimen. We therefore set out to test two different doses of a new formulation of immunoglobulin termed IGIV-C 10% for suppression of both clinical and MRI disease activity as well as safety. Methods: One hundred twenty-seven patients with RRMS participated in this multicenter, randomized, double-blind, placebo-controlled trial. Forty-four and 42 patients received treatment with 0.2 and 0.4 g/kg of IGIV-C 10%, and 41 patients received an equal volume of placebo (0.1% albumin) every 4 weeks for 48 weeks. The primary endpoint was the proportion of relapse-free patients. The main secondary endpoint was lesion activity assessed by 6-weekly MRI. Results: Baseline variables were similar in IVIG- and placebo-treated groups. After 1 year, the proportion of relapse-free patients did not differ statistically according to treatment (IVIG 0.2 g/kg: 57%; IVIG 0.4 g/kg: 60%; placebo: 68%), and there was no difference regarding the cumulative number of unique newly active MRI lesions (median numbers: IVIG 0.2 g/kg: 8.0; IVIG 0.4 g/kg: 5.0; placebo: 7.2) after 48 weeks. There were no significant between-group differences in the rates of adverse events. Conclusion: Although IV immunoglobulin (IVIG) treatment was well tolerated, this study did not substantiate a beneficial effect of IVIG in doses ranging from 0.2 to 0.4 g/kg. This result seriously questions the utility of IVIG for the treatment of relapsing-remitting multiple sclerosis.