Efficacy of Dysport ® (Botulinum toxin type A) for the treatment of cervical dystonia: A multicenter, randomized, double-blind, placebo-controlled phase III study

Abstract

Single, intramuscular (IM) doses of Dysport were used in the treatment of cervical dystonia (CD). Dysport 500 unit (U) or placebo was used, with injection sites and dose decided at baseline. Efficacy assessments include Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS) total and subscale scores, visual analog scale (VAS) for pain, subject/investigator's VAS for symptom assessments, investigator's global assessment of pain and symptoms at week 12 and SF-36 QOL scores at week 8. Mean TWSTRS scores improved markedly for Dysport compared to placebo at week 4 and significantly at weeks 8 and 12. Adjusted least squares mean (SE) TWSTRS total score improved by 15.6 Dysport vs. 6.7 placebo. TWSTRS total score maintained continued improvement at weeks 8 (14.7 vs. 5.9) and 12 (9.1 vs. 4.9) for Dysport and placebo, respectively. VAS for pain was always lower with Dysport, with greater reduction in VAS pain score at weeks 4 and 8 (−17.7±24.4 and −15.8±30.9, respectively) and less at week 12 (−7.9±27.5), similar trends are seen for TWSTRS pain subscale scores. For Dysport, SF-36 summary score at week 8 and proportion of treatment successes at week 12 were also significantly better compared to placebo. Most adverse events were mild or moderate in nature and typical of the known safety profile of Dysport in CD. The study demonstrates the superior efficacy and benefit, compared to placebo, of a single, IM 500 U Dysport dose in the treatment of CD. Supported by Ipsen Ltd.