title: Neuroprotection trials in Parkinson's disease: systematic review.
abstract: Treatments to slow the progression are a major unmet need in Parkinson's disease. Detailed assessment of randomized trials testing putative neuroprotective drugs was undertaken to inform the design, reporting, and interpretation of future studies. This study is a systematic review of trials testing neuroprotective drugs. Data were extracted independently by two coauthors. Fifteen completed, published trials involving 4,087 participants tested 13 different drugs in 18 double-blind comparisons with placebo. Seven comparisons involving 2,000 subjects assessed MAO-B inhibitors. The primary outcome was change in the Unified Parkinson's Disease Rating Scale score in eight trials and time to need for dopaminergic therapy in seven. Mean participant age was 62 years, 35% were women, the interval from diagnosis to entry averaged 11 months, and the number of participants averaged 272 (largest = 806). Follow-up averaged <16 months in all but two trials. Detailed randomization methods and success of double-blinding were reported in 20% and 13%, respectively. Based on the investigators' conclusions, six trials were interpreted as consistent with a neuroprotective effect, three as negative, and five as either confounded or not meeting criteria for futility. Neuroprotection trials have involved relatively uniform groups of participants early in the clinical disease course, with outcomes weighted heavily toward motor deterioration. Future trials should include participants with wider ranges of disease stages and assess broader neurological outcomes.
authors.affiliation: Department of Neurology, University of Texas Health Science Center, San Antonio, Texas 78229-3900, USA. hartr@uthscsa.edu
authors.forename: Robert G
authors.initials: RG
authors.lastname: Hart
authors.forename: Lesly A
authors.initials: LA
authors.lastname: Pearce
authors.forename: Bernard M
authors.initials: BM
authors.lastname: Ravina
authors.forename: Toby C
authors.initials: TC
authors.lastname: Yaltho
authors.forename: John R
authors.initials: JR
authors.lastname: Marler
mesh_terms: D006801:Humans; D008996:Monoamine Oxidase Inhibitors / Q000627:therapeutic use; D018696:Neuroprotective Agents / Q000627:therapeutic use*; D010300:Parkinson Disease / Q000188:drug therapy*; D016032:Randomized Controlled Trials as Topic
chemical_list: D008996:Monoamine Oxidase Inhibitors; D018696:Neuroprotective Agents