Open-label Extension Study of AbobotulinumtoxinA (Dysport®) for the Treatment of Cervical Dystonia

Study Overview
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Brief Summary
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The aim of this study is to assess longer term safety and effectiveness of Dysport®.

Official Title
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A Phase III, Prospective, Multicenter, Open-label Extension Study to Assess the Longer Term Safety and Efficacy of Repeated Treatment of Dysport® Intramuscular Injection in the Treatment of Cervical Dystonia

Conditions
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Cervical Dystonia

Intervention / Treatment
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* Biological: Botulinum toxin type A


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Subjects enrolled in the Y-47-52120-051 study, who have completed all study visits up to Week 12, or up to Week 4 in the event of an early withdrawal Returned to pre-treatment status as judged by the Investigator Exclusion Criteria: Pure anterocollis or pure retrocollis Known antibodies to botulinum toxin type A Requirement for botulinum toxin injections to site(s) other than the neck and unable to avoid such treatment for the duration of the study Known significant underlying swallowing or respiratory abnormality which might be exacerbated by botulinum toxin treatment

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Dysport<br>250-1000 units | Biological: Botulinum toxin type A<br>* In this long-term extension study, a dose of 500 units Dysport was administered by intramuscular injection into the clinically indicated neck muscles in a single dosing session in the first treatment cycle. This was the same dose as given in the preceding study NCT00257660 (Y-47-52120-051). Based on individual safety & efficacy, subjects could then receive up to 3 subsequent injections with doses titrated in 250 unit steps, to a minimum of 250 units and a maximum of 1000 units. Retreatment occurred approximately 12-16 weeks after the previous injection, with the exact timing based on clinical need.<br>* Other names: AbobotulinumtoxinA (Dysport®);|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Toronto Western Spasmodic Torticollis Rating Scale Total Score From Baseline | TWSTRS is comprised of three different components which are severity, disability & pain. There is an ordinal scale for each component and the score range for each is the following: for severity from 0 (absence of severity) to 35 (max severity), for disability from 0 (no disability) to 30 (max disability) and for pain from 0 (no pain) to 20 (max pain). TWSTRS total score is the sum of the 3 component scores, with a range from 0 to a maximum of 85. For each treatment cycle, the change in TWSTRS total score is the score at week 4 minus the score at baseline. | Week 4 follow-up visit | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Toronto Western Spasmodic Torticollis Rating Scale Severity Subscale as a Change From Baseline | TWSTRS is comprised of three different components which are severity, disability & pain. There is an ordinal scale for each component and the score range for severity is from 0 (absence of severity) to 35 (max severity). For each treatment cycle, the change in TWSTRS severity subscale is the score at week 4 minus the score at baseline. | Week 4 follow-up visit | 
| Toronto Western Spasmodic Torticollis Rating Scale Disability Subscale Score as a Change From Baseline | TWSTRS is comprised of three different components which are severity, disability & pain. There is an ordinal scale for each component and the score range for disability is from 0 (no disability) to 30 (max disability). For each treatment cycle, the change in TWSTRS disability subscale is the score at week 4 minus the score at baseline. | Week 4 follow-up visit | 
| Toronto Western Spasmodic Torticollis Rating Scale Pain Subscale Score as a Change From Baseline | TWSTRS is comprised of three different components which are severity, disability & pain. There is an ordinal scale for each component and the score range for pain is from 0 (no pain) to 20 (max pain). For each treatment cycle, the change in TWSTRS pain subscale is the score at week 4 minus the score at baseline. | Week 4 follow-up visit |