A multicenter, randomized, double-blind, placebo-controlled trial of long-term ascorbic acid treatment in Charcot-Marie-Tooth disease type 1A (CMT-TRIAAL): The study protocol [EudraCT no.: 2006-000032-27]

There is no treatment for Charcot-Marie-Tooth disease 1A (CMT1A), but ascorbic acid (AA) is efficacious in the transgenic mouse model. Thus, a clinical trial of AA in CMT1A is warranted. The CMT-TRIAAL is a phase III randomized, double-blind, placebo-controlled study involving 222 CMT1A adults from eight Italian centers. Eligible for the study are symptomatic adults with genetically confirmed CMT1A. Treatment consists of 2-year oral AA (1500 mg/day) or placebo. The primary trial endpoint is an improvement in CMT Neuropathy Score. Secondary efficacy endpoints are changes in distal arm and leg maximum voluntary isometric contraction; 10 m timed walking; 9-hole-peg test; overall neuropathy limitations scale; pain and fatigue visual analog scales; health-related quality of life (SF-36); and electrophysiology. Clinical-electrophysiological assessments are performed at baseline and every 6 months thereafter. In consenting patients from three centers, skin biopsy is performed to evaluate PMP22 expression. The study will last 34 months, starting from March 2006. (c) 2006 Elsevier Ltd. All rights reserved.