Background
Intravenous immunoglobulin (IVIg) and corticosteroids are considered first-line but alternative induction treatments for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). We aimed to establish if combining these induction treatments led to more frequent remissions from CIDP than IVIg alone.
Methods
We conducted a randomised, double-blind, placebo-controlled study in people with CIDP. Participants were allocated in a 1:1 ratio to receive either intravenous methylprednisolone (IVMP, 1000 mg) or placebo, both administered in combination with IVIg every three weeks for a total of 18 weeks. The primary outcome was remission, defined as sustained improvement on disability scales at 52 weeks without need for further treatment. Analyses were performed in the intention-to-treat and per-protocol datasets. Secondary outcomes included between group differences on eight outcome measures at 18 weeks and at endpoint compared with baseline. Study was registered with the ISRCTN registry (ISRCTN15893334).
Findings
Inclusion was stopped prematurely after inclusion of 77 of 96 planned participants because of safety concerns, as four thromboembolic events occurred in the IVMP group compared with none in the placebo group. Thirty-seven participants had been assigned to receive IVMP and 40 to receive placebo at termination. Fourteen (38%) participants in the IVMP group were in remission at 52 weeks compared with 11 (28%) in the placebo group, with a difference of 10% (95% CI -11 to 31, p=0·47). There was no statistically significant difference in the proportion of participants improving during 18 weeks of treatment or in total number of adverse events. Secondary outcomes demonstrated greater magnitude of improvement in the IVMP group compared to placebo.
Interpretation
Combined treatment with IVIg and IVMP did not lead to more frequent remissions than treatment with IVIg alone. The IVMP group appeared to have greater magnitude of improvement on secondary outcome measures, but a potentially higher risk of thromboembolic events.
Time period end date is an estimation (inclusion of last participant plus one year). Data regarding the long-term (2 year) follow-up is not inckluded in this dataset.
As of yet unpublished
