Intramuscular interferon beta-1a in chronic inflammatory demyelinating polyradiculoneuropathy.

Abstract

OBJECTIVE:

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) shares immunologic features with multiple sclerosis (MS). Because IM interferon beta-1a (IM IFNbeta-1a) is an effective and safe treatment for MS, we conducted a dose-ranging efficacy study of IFNbeta-1a in patients with CIDP.

METHODS:

Adults with IV immunoglobulin (IVIg)-dependent CIDP (n = 67) were enrolled in this 32-week double-blind trial and randomized to IM IFNbeta-1a. Patients received 30 microg once weekly plus placebo (n = 12), IM IFNbeta-1a 60 microg once weekly plus placebo (n = 11), IM IFNbeta-1a 30 microg twice weekly (n = 11), IM IFNbeta-1a 60 microg twice weekly (n = 11), or placebo twice weekly (n = 22). Participants were maintained on IVIg through week 16, when IVIg was discontinued. Patients who worsened were restarted on IVIg. The primary outcome was total IVIg dose (g/kg) administered from week 16 to 32.

RESULTS:

There was no difference in total IVIg dose administered after week 16 for patients treated with IFNbeta-1a (1.20 g/kg) compared with placebo (1.34 g/kg; p = 0.75). However, exploratory analyses suggested IFNbeta-1a significantly reduced total dose of IVIg compared with placebo for participants who required either high-dose IVIg (>0.95 g/kg per month) or had greater weakness at baseline (Medical Research Council sum score <51). Adverse events included flu-like symptoms, headache, and fatigue in the IFNbeta-1a groups.

CONCLUSIONS:

Interferon beta-1a (IFNbeta-1a) therapy did not provide significant benefit over IV immunoglobulin (IVIg) therapy alone for patients with chronic inflammatory demyelinating polyradiculoneuropathy. However, IFNbeta-1a might be beneficial for patients with more severe disability or those needing high doses of IVIg.

LEVEL OF EVIDENCE:

This study was designed to provide Class I evidence for the safety and efficacy of IM IFNbeta-1a in the treatment of CIDP but has been subsequently classified as Class II due to a >20% patient dropout rate. Thus, this randomized, controlled clinical trial provides Class II evidence of no effect on primary and secondary endpoints of 4 dosage regimens of IM IFNbeta-1a added to IVIg in persons with CIDP.

• Authors: R A C Hughes, K C Gorson, D Cros, J Griffin, J Pollard, J-M Vallat, S L Maurer, K Riester, G Davar, K Dawson, A Sandrock, Avonex CIDP Study Group
• Journal: Neurology (Neurology) Vol. 74 Issue 8 Pg. 651-7 (Feb 23 2010) ISSN: 1526-632X [Electronic] United States
• PMID: 20177118 (Publication Type: Clinical Trial, Phase II, Journal Article, Multicenter Study, Randomized Controlled Trial, Research Support, Non-U.S. Gov't)

Chemical References

• Adjuvants, Immunologic
• Interferon-beta
• Interferon beta-1a

Topics

• Adjuvants, Immunologic (administration & dosage, adverse effects)
• Adolescent
• Adult
• Aged
• Analysis of Variance
• Dose-Response Relationship, Drug
• Double-Blind Method
• Drug Administration Schedule
• Fatigue (chemically induced)
• Female
• Headache (chemically induced)
• Humans
• Injections, Intramuscular
• Interferon beta-1a
• Interferon-beta (administration & dosage, adverse effects)
• Kaplan-Meier Estimate
• Male
• Middle Aged
• Polyradiculoneuropathy, Chronic Inflammatory Demyelinating (drug therapy)
• Proportional Hazards Models
• Regression Analysis
• Treatment Outcome