Placebo effect in chronic inflammatory demyelinating polyneuropathy: ThePATHstudy and a systematic review

Richard A. Lewis*, David R. Cornblath, Hans-Peter Hartung, Gens Sobue, John-Philip Lawo, Orell Mielke, Billie L. Durn, Vera Bril, Ingemar S. J. Merkies, Paul Bassett, Alexa Cleasby, Ivo N. van Schaik, PATH Study Grp

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

10 Citations (Web of Science)

Abstract

The Polyneuropathy And Treatment with Hizentra (PATH) study required subjects with chronic inflammatory demyelinating polyneuropathy (CIDP) to show dependency on immunoglobulin G (IgG) and then be restabilized on IgG before being randomized to placebo or one of two doses of subcutaneous immunoglobulin (SCIG). Nineteen of the 51 subjects (37%) randomized to placebo did not relapse over the next 24 weeks. This article explores the reasons for this effect. A post-hoc analysis of the PATH placebo group was undertaken. A literature search identified other placebo-controlled CIDP trials for review and comparison. In PATH, subjects randomized to placebo who did not relapse were significantly older, had more severe disease, and took longer to deteriorate in the IgG dependency period compared with those who relapsed. Published trials in CIDP, whose primary endpoint was stability or deterioration, had a mean non-deterioration (placebo effect) of 43%, while trials with a primary endpoint of improvement had a placebo response of only 11%. Placebo is an important variable in the design of CIDP trials. Trials designed to show clinical improvement will have a significantly lower effect of this phenomenon than those designed to show stability or deterioration.

Original languageEnglish
Pages (from-to)230-237
Number of pages8
JournalJournal of the Peripheral Nervous System
Volume25
Issue number3
Early online date5 Aug 2020
DOIs
Publication statusPublished - Sep 2020

Keywords

  • CIDP
  • immunoglobulin
  • non-relapse
  • placebo
  • relapse
  • INTRAVENOUS IMMUNOGLOBULIN TREATMENT
  • DOUBLE-BLIND
  • SUBCUTANEOUS IMMUNOGLOBULIN
  • INTERFERON BETA-1A
  • PLASMA-EXCHANGE
  • TRIAL
  • THERAPY

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