Lower, More Frequent Dosing of IVIG-Dependent CIDP Patients Does Not Improve Efficacy or Safety in CIDP

High peak serum immunoglobulin G (IgG) levels associated with infrequent high doses of maintenance intravenous immune globulin (IVIG) treatment may not be needed for effective treatment of chronic inflammatory demyelinating polyneuropathy (CIDP), but may cause side effects and result in lower IgG trough levels than more frequent divided IVIG dosage regimens. A team of Dutch investigators conducted a randomized trial to learn whether lower, more frequent IVIG dosing — associated with more stable IgG levels and higher trough levels — might improve efficacy or reduce side effects.

Twenty-five IVIG-dependent CIDP patients were randomized to a placebo group that received their full, individually established IVIG dose at their usual interval, followed by a placebo infusion at one-half of the usual interval. Intervention group patients received one-half of their usual dose at one-half their usual interval, with the half repeated at the end of their usual interval. After a wash-out phase, patients were crossed over to the alternative treatment regimen. The primary outcome was handgrip strength. Secondary outcomes included health-related quality of life, disability, fatigue and side effects.

At baseline, patients had individually adjusted IVIG dosages ranging from 20 grams to 80 grams, and intervals ranging from 14 days to 35 days. In the 22 patients who completed both treatment periods, there was no significant difference in handgrip strength change from baseline between the established dosage regimen and the lower, more frequent dosage regimen. Nor were there significant differences in side effects or any of the secondary outcomes. The investigators concluded lower, more frequent dosing does not further improve the efficacy of IVIG in stable IVIG-dependent CIDP patients, or result in fewer side effects.