Ontology highlight
ABSTRACT: Importance
No current medications improve neuropathy in subjects with Charcot-Marie-Tooth disease type 1A (CMT1A). Ascorbic acid (AA) treatment improved the neuropathy of a transgenic mouse model of CMT1A and is a potential therapy. A lower dosage (1.5 g/d) did not cause improvement in humans. It is unknown whether a higher dosage would prove more effective.Objective
To determine whether 4-g/d AA improves the neuropathy of subjects with CMT1A.Design
A futility design to determine whether AA was unable to reduce worsening on the CMT Neuropathy Score (CMTNS) by at least 50% over a 2-year period relative to a natural history control group.Setting
Three referral centers with peripheral nerve clinics (Wayne State University, Johns Hopkins University, and University of Rochester).Participants
One hundred seventy-four subjects with CMT1A were assessed for eligibility; 48 did not meet eligibility criteria and 16 declined to participate. The remaining 110 subjects, aged 13 to 70 years, were randomly assigned in a double-masked fashion with 4:1 allocation to oral AA (87 subjects) or matching placebo (23 subjects). Sixty-nine subjects from the treatment group and 16 from the placebo group completed the study. Two subjects from the treatment group and 1 from the placebo group withdrew because of adverse effects.Interventions
Oral AA (4 g/d) or matching placebo.Main outcomes and measures
Change from baseline to year 2 in the CMTNS, a validated composite impairment score for CMT.Results
The mean 2-year change in the CMTNS was -0.21 for the AA group and -0.92 for the placebo group, both better than natural history (+1.33). This was well below 50% reduction of CMTNS worsening from natural history, so futility could not be declared (P > .99).Conclusions and relevance
Both treated patients and those receiving placebo performed better than natural history. It seems unlikely that our results support undertaking a larger trial of 4-g/d AA treatment in subjects with CMT1A.Trial registration
clinicaltrials.gov Identifier: NCT00484510.
SUBMITTER: Lewis RA
PROVIDER: S-EPMC3752369 | biostudies-literature | 2013 Aug
REPOSITORIES: biostudies-literature
Lewis Richard A RA McDermott Michael P MP Herrmann David N DN Hoke Ahmet A Clawson Lora L LL Siskind Carly C Feely Shawna M E SM Miller Lindsey J LJ Barohn Richard J RJ Smith Patricia P Luebbe Elizabeth E Wu Xingyao X Shy Michael E ME
JAMA neurology 20130801 8
<h4>Importance</h4>No current medications improve neuropathy in subjects with Charcot-Marie-Tooth disease type 1A (CMT1A). Ascorbic acid (AA) treatment improved the neuropathy of a transgenic mouse model of CMT1A and is a potential therapy. A lower dosage (1.5 g/d) did not cause improvement in humans. It is unknown whether a higher dosage would prove more effective.<h4>Objective</h4>To determine whether 4-g/d AA improves the neuropathy of subjects with CMT1A.<h4>Design</h4>A futility design to d ...[more]