IncobotulinumtoxinA Treatment in Upper‐Limb Poststroke Spasticity in the Open‐Label Extension Period of PURE: Efficacy in Passive Function, Caregiver Burden, and Quality of Life

Background Poststroke spasticity affects motor function and the ability to perform activities of daily living, with the potential to affect quality of life (QoL) and increase caregiver burden. Objective To investigate the effect of repeated incobotulinumtoxinA treatment on spasticity‐associated functional disability, caregiver burden, and QoL in the 36‐week open‐label extension of the phase 3 PURE study (NCT01392300). Design Open‐label extension period of a prospective, double‐blind, placebo‐controlled, randomized, multicenter study. Setting Forty‐six investigation sites in seven countries (Czech Republic, Germany, Hungary, India, Poland, Russia, United States). Participants Adults, aged 18‐80 years, ≥12 months since last botulinum neurotoxin injection or entirely toxin naïve, with median poststroke upper‐limb spasticity of >2 years' duration. Methods Participants who completed the 12‐week, double‐blind main period could enter the open‐label extension and receive up to three additional incobotulinumtoxinA treatments (fixed total dose 400 U at 12‐week intervals) into the affected muscles of one upper limb. Main Outcome Measures Functional disability (Disability Assessment Scale; DAS), caregiver burden (Carer Burden Scale), and quality of life (QoL; EuroQol [EQ] 5‐dimensions three‐level [EQ‐5D‐3L]). Results The open‐label extension included 296 treated patients. Mean DAS score for the principal target domain improved significantly from the main period baseline to the end‐of‐study visit (P