Intravenous immunoglobulin for chronic inflammatory demyelinating polyradiculoneuropathy: the ICE trial

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a potentially disabling autoimmune disease causing progressive or relapsing remitting weakness with or without sensory loss. Previous small trials demonstrated short-term benefit from intravenous immunoglobulin (IVIg), and international guidelines recommend IVIg as an option. However, evidence had been insufficient to persuade authorities to approve IVIg for use in CIDP. This article aims to review the Immune Globulin Intravenous CIDP Efficacy (ICE) trial, which was a randomized, double-blind, placebo-controlled, response-conditional crossover trial of Gamunex (R) (intravenous immunoglobulin, 10% caprylate/chromatography purified). With 117 participants, it is the largest treatment trial ever conducted in CIDP. The results showed unequivocal short- and long-term benefit from IVIg in confirmation of previous reports. The trial also showed for the first time that continued IVIg infusion 1 g/kg every 3 weeks protected participants from relapse. Adverse events were mostly mild and serious adverse events were not more common with IVIg than with placebo. The results persuaded the US FDA and Health Canada to approve Gamunex for use in CIDP.