Abstract
The objective of this study was to compare efficacy, safety, and duration of botulinum toxin type A (BoNT‐A) and type B (BoNT‐B) in toxin‐naïve cervical dystonia (CD) subjects. BoNT‐naïve CD subjects were randomized to BoNT‐A or BoNT‐B and evaluated in a double‐blind trial at baseline and every 4‐weeks following one treatment. The primary measure was the change in Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) from baseline to week 4 post‐injection. Secondary measures included change in TWSTRS‐subscale scores, pain, global impressions, and duration of response and safety assessments. The study was designed as a noninferiority trial of BoNT‐B to BoNT‐A. 111 subjects were randomized (55 BoNT‐A; 56 BoNT‐B). Improvement in TWSTRS‐total scores 4 weeks after BoNT‐B was noninferior to BoNT‐A (adjusted means 11.0 (SE 1.2) and 8.8 (SE 1.2), respectively; per‐protocol‐population (PPP)). The median duration of effect of BoNT‐A and BoNT‐B was not different (13.1 vs. 13.7 weeks, respectively; P‐value = 0.833; PPP). There were no significant differences in the occurrence of injection site pain and dysphagia. Mild dry mouth was more frequent with BoNT‐B but there were no differences for moderate/severe dry mouth. In this study, both BoNT‐A and B were shown to be effective and safe for the treatment of toxin‐naive CD subjects. © 2007 Movement Disorder Society