title: Designing clinical trials for dystonia.
abstract: With advances in the understanding of the pathophysiology of dystonia, novel therapeutics are being developed. Such therapies will require clinical investigation ranging from exploratory studies to examine safety, tolerability, dosage selection, and preliminary efficacy to confirmatory studies to evaluate efficacy definitively. As dystonia is a rare and complex disorder with clinical and etiological heterogeneity, clinical trials will require careful consideration of the trial design, including enrollment criteria, concomitant medication use, and outcome measures. Given the complexities of designing and implementing efficient clinical trials, it is important for clinicians and statisticians to collaborate closely throughout the clinical development process and that each has a basic understanding of both the clinical and statistical issues that must be addressed. To facilitate designing appropriate clinical trials in this field, we review important general clinical trial and regulatory principles, and discuss the critical components of trials with an emphasis on considerations specific to dystonia. Additionally, we discuss designs used in early exploratory, late exploratory, and confirmatory phases, including adaptive designs.
authors.affiliation: National Institute of Neurological Disorders and Stroke, National Institutes of Health, 6001 Executive Blvd., Rm 2225, Bethesda, MD, 20892, USA, galpernw@ninds.nih.gov.
authors.forename: Wendy R
authors.initials: WR
authors.lastname: Galpern
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Coffey
authors.forename: Alberto
authors.initials: A
authors.lastname: Albanese
authors.forename: Ken
authors.initials: K
authors.lastname: Cheung
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Comella
authors.forename: Dixie J
authors.initials: DJ
authors.lastname: Ecklund
authors.forename: Stanley
authors.initials: S
authors.lastname: Fahn
authors.forename: Joseph
authors.initials: J
authors.lastname: Jankovic
authors.forename: Karl
authors.initials: K
authors.lastname: Kieburtz
authors.forename: Anthony E
authors.initials: AE
authors.lastname: Lang
authors.forename: Michael P
authors.initials: MP
authors.lastname: McDermott
authors.forename: Jeremy M
authors.initials: JM
authors.lastname: Shefner
authors.forename: Jan K
authors.initials: JK
authors.lastname: Teller
authors.forename: John L P
authors.initials: JL
authors.lastname: Thompson
authors.forename: Sharon D
authors.initials: SD
authors.lastname: Yeatts
authors.forename: H A
authors.initials: HA
authors.lastname: Jinnah
mesh_terms: D002986:Clinical Trials as Topic / Q000379:methods*; D004421:Dystonia / Q000209:etiology / Q000628:therapy*; D006801:Humans; D017063:Outcome Assessment, Health Care; D012107:Research Design