title: Efficacy and Safety of IncobotulinumtoxinA in Subjects Previously Treated with Botulinum Toxin Versus Toxin-Naïve Subjects with Cervical Dystonia.
abstract: BACKGROUND
  To determine whether botulinum toxin treatment history affected the outcomes of a study comparing the safety and efficacy of incobotulinumtoxinA with placebo in subjects with cervical dystonia (CD).
  
  
  METHODS
  This was a prospective, double-blind, randomized, placebo-controlled, multicenter trial in botulinum toxin-treated or toxin-naïve CD subjects. Subjects received a fixed dose of either 120 U or 240 U of incobotulinumtoxinA or placebo. The primary outcome measure was change from baseline to Week 4 in the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total score. Treatment-emergent adverse events (TEAEs) were also evaluated. This report represents a subgroup analysis of botulinum toxin-treated or toxin-naïve subjects.
  
  
  RESULTS
  Participants (N = 233; 38.6% toxin-naïve) had a mean age of 52.8 years. IncobotulinumtoxinA significantly improved TWSTRS total scores from baseline to Week 4 in both dose groups versus placebo, and the improvement persisted through the end of the study (≤20 weeks). Both the previously toxin-treated and toxin-naïve subjects demonstrated significant improvements in TWSTRS total scores at Week 4 compared to baseline. The most frequent TEAEs in the incobotulinumtoxinA groups were dysphagia, neck pain, and muscular weakness, which were generally mild. TEAEs were more common in the 240 U group and toxin-naïve subjects.
  
  
  CONCLUSIONS
  Overall, incobotulinumtoxinA was safe and effective in CD, regardless of toxin therapy history. A lower starting dose may be better tolerated among toxin-naïve subjects without sacrificing efficacy.
authors.affiliation: Cleveland Clinic, Cleveland, Ohio, United States of America.
authors.forename: Hubert H
authors.initials: HH
authors.lastname: Fernandez
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Pappert
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Comella
authors.forename: Virgilio Gerald H
authors.initials: VG
authors.lastname: Evidente
authors.forename: Daniel D
authors.initials: DD
authors.lastname: Truong
authors.forename: Amit
authors.initials: A
authors.lastname: Verma
authors.forename: Joseph
authors.initials: J
authors.lastname: Jankovic
keywords: Botulinum toxin type A; cervical dystonia; incobotulinumtoxinA; pretreated; treatment-naïve