Intravenous immunoglobulin for chronic residual peripheral neuropathy in microscopic polyangiitis: A multicentre randomised double-blind trial.

Abstract

We conducted a Phase 3, multicentre randomised, double-blind, placebo-controlled, parallel-group trial to evaluate efficacy and safety of intravenous immunoglobulin (IVIg) in patients with glucocorticoid-refractory neuropathy associated with microscopic polyangiitis. Patients received immunoglobulin or placebo intravenously for five consecutive days at baseline and after four weeks. IVIg and placebo groups received placebo and IVIg, respectively, after eight weeks. The primary and major secondary endpoint were least squares mean (LS mean) of change in manual muscle test (MMT) sum score after eight and four weeks, respectively. A total of 37 patients were randomised into two groups (IVIg 19, placebo 18). The LS mean for change in MMT sum score after eight weeks was 9.02 for IVIg and 6.71 for placebo (difference 2.32, 95% CI -2.60 to 7.23, p = .345) and after four weeks was 6.81 and 2.83 (difference 3.99, 95% CI -1.22 to 9.19, p = .129). There were no new safety concerns for IVIg. MMT sum scores improved with IVIg compared with placebo after eight weeks of dosing and two courses of treatment, but the differences were not statistically significant, and the results showed no clear efficacy of IVIg in this patient population. No new safety concerns were raised.