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 <.0001). Carer Burden Scale scores also significantly improved from the main period baseline to the end-of-study visit (P <.05 for all caregiving activities except “applying a splint”). At the end-of-study visit, versus the main period baseline, 19.7%-33.3% of patients experienced improvements for each parameter on the EQ-5D-3L, except “mobility,” with significant improvement in EQ-5D visual analog scale scores (P <.001). Conclusions: Repeated incobotulinumtoxinA treatments at 12-week intervals in participants with chronic poststroke upper-limb spasticity resulted in significant improvements in QoL, as well as significant reductions in upper-limb functional disability and caregiver burden.