Botulinum toxin type B: A double-blind, placebo-controlled, safety and efficacy study in cervical dystonia

Abstract

We enrolled and treated 122 patients with idiopathic cervical dystonia in a double-blind, placebo-controlled safety and efficacy study of botulinum toxin type B (BotB). Both A-responsive and A-resistant patients were enrolled. Patients received intramuscular injections of either BotB (2,500 U, 5,000 U, or 10,000 U) or placebo. The primary outcome measure of efficacy was the Toronto Western Spasmodic Torticollis Rating Scale (TWSTRS)-Total score at 4 weeks following study drug administration. Secondary measures of efficacy were TWSTRS-Severity, -Disability, and -Pain subscale scores, and Analog Pain Assessment, Investigator Global Assessment, Patient Global Assessment, and Sickness Impact Profile scores. Duration of effect was estimated with an intent-to-treat analysis of responders. Safety measures included clinical parameters, laboratory tests, and adverse events. The primary and most of the secondary analyses indicated a statistically significant treatment effect and a dose response. BotB is safe, well tolerated, and efficacious in the treatment of cervical dystonia at the doses tested.

Pharmacology and immunology of botulinum toxin serotypes

“…To date, the vast majority of commercial development of botulinum toxin for clinical use has been based on BTX-A. However, studies indicate that botulinum neurotoxin serotypes B (BTX-B) and F (BTX-F) may be useful for the treatment of cervical dystonia or blepharospasm [6,7,11], especially for patients with cervical dystonia that no longer respond to BTX-A [8,12]. Clinical studies have found that BTX-A is more potent (less total number of units administered per patient per session) than BTX-B [7,8,13] and has a longer duration of action than either BTX-B, as indicated by electromyography (EMG) results only [13], or BTX-F as indicated by clinical response [6,12,14].…”

Severity and impact of xerostomia in patients treated with botulinum toxin type b for cervical dystonia: Observations on the quality of life of patients with xerostomia

“…6,7,11 Thus, the AE data obtained in controlled studies with doses of 2500 and 5000 U may not be entirely applicable to clinical practice. As shown in Figure 1, an apparent increase in dosages was observed over time in the present study, although the numbers of patients at each injection were not the same, with only a few patients having received 6 or 7 injections.…”

“…Thus, the present results apply only to the population of patients who reported xerostomia following botulinum toxin type B treatment. In controlled trials, 6,7,11 the percentage of patients with cervical dystonia reporting xerostomia following treatment with botulinum toxin type B ranged from 24% to 44% versus 3% with placebo.…”

Assessment: Botulinum neurotoxin for the treatment of movement disorders (an evidence-based review) [RETIRED]

“…Four Class I studies enrolled subjects with previous response to BoNT. Three studies assessed safety and efficacy of BoNT-B, 10,11,14 and one assessed safety and efficacy of BoNT-A. 13 One of these studies randomized 109 subjects with CD to placebo, medium dose, or high dose of BoNT-B.…”