Primary results from the Cervical Dystonia Patient Registry for Observation of OnabotulinumtoxinA Efficacy (CD PROBE)

Background The Cervical Dystonia Patient Registry for Observation of OnabotulinumtoxinA Efficacy (CD PROBE; NCT00836017) is a prospective, observational, multicenter, real-world registry designed to assess the safety, effectiveness, and treatment utilization following multiple treatments of onabotulinumtoxinA. Methods Subjects were naïve to botulinum toxin, new to practice, or had not received toxin in ≤16 weeks if in a clinical trial. Dosages and treatment intervals varied due to the real-world design. Descriptive and inferential statistics evaluated changes over 3 treatments. Results 1046 subjects enrolled. Subjects were 74.4% female, 63.5% toxin-naïve, mean age 58.0 ± 14.7 years. The mean dose over 2481 treatment sessions was 189.8 ± 87.1 U, with average treatment intervals of 14.6 and 15.1 weeks. The mean Toronto Western Spasmodic Torticollis Rating Scale Total score in subjects who completed all assessments (n = 479) decreased from 39.2 at baseline to 27.1 at final visit (P <.0001). A high percentage of physicians reported improvement in Clinician Global Impression of Change after initial assessment; this significantly increased at final assessment (n = 479, 91.2% vs 95.0%; P <.0001). Similarly, a high percentage of subjects reported improvement in Patient Global Impression of Change after initial assessment, which significantly increased at final assessment (n = 470, 83.0% vs 91.7%; P <.0001). Significant reductions in all Cervical Dystonia Impact Profile-58 scores were observed (n = 407). Overall, 26.2% of subjects reported adverse events, including muscular weakness (7.0%) and dysphagia (6.4%). Conclusions Results indicate robust improvement in clinical ratings and excellent tolerability following onabotulinumtoxinA treatment of CD.