BotB (botulinum Toxin type B): Evaluation of safety and tolerability in botulinum toxin type A‐Resistant cervical dystonia patients (preliminary study)

Abstract

Botulinum toxin (BTX) injection is considered the treatment of choice for patients with cervical dystonia (torticollis). We conducted a pilot, open‐label, dose‐escalation study with BTX type B in 12 patients who no longer responded clinically to injections with BTX type A. At the doses tested, BTX type B was safe and well tolerated without evidence of dose‐limiting toxicity in this patient population. Mild‐to‐moderate adverse events generally resolved quickly and included asthenia, pain, nausea, dysphagia, hypertonia, and tremor. No serious adverse events or antibodies to type‐B treatment were reported. Low‐dosing‐session (100‐‐899 units) and high‐dosing‐session (900–1,500 units) groups were defined based on units administered per dosing session. Toronto Western Spasmodic Torticollis Rating Scale‐Severity Scale (TWSTRS‐Severity), Patient Analogue Pain Scale, and Physician and Patient Global Assessment Scales were measured during this study. The TWSTRS‐Severity mean maximum percent improvement from baseline demonstrated a 9.9% versus 28.8% difference between the low‐dose and high‐dose groups, respectively. Effectiveness was noted for the high‐dose group on the Patient Analogue Pain Scale but not on the Global Assessment Scales.