Real-world effectiveness of abobotulinumtoxinA (Dysport®) in adults with upper limb spasticity in routine clinical practice: an observational study

AbobotulinumtoxinA (aboBoNT-A, Dysport (R)) is used in clinical practice as a well-tolerated and effective therapy for muscle spasticity. AboBoNT-A has been shown to reduce upper and lower limb spastic paresis in clinical trials, demonstrating improvements in muscle tone and limb function. This open-label, multicentre, observational, non-interventional study was the first to investigate aboBoNT-A's efficacy in adult patients with upper limb spasticity (ULS) in routine clinical practice in Poland. All enrolled patients received >= 1 aboBoNT-A injection cycles, per routine clinical practice (full analysis set, FAS), and >= 1 rehabilitation session. Patients attended a baseline visit (V1) and two follow-up visits (V2, V3) for retreatment, depending on the investigator's assessment of individual patient needs, with a mean interval (SD) between injections of 4.4 (1.4) and 4.5 (1.2) months. The primary effectiveness endpoint was patient- and physician-based evaluation using the Clinical Global Impression-Improvement Scale (CGI-I), a validated 7-point scale (1 = very much improved to 7 = very much worse) relative to baseline. CGI-I has not previously been used as a primary endpoint in studies evaluating ULS. Secondary endpoints included muscle tone in shoulder, elbow, carpal joint, and finger muscles, measured by the Modified Ashworth Scale (MAS), and muscle strength according to the Medical Research Council scale (MRC). Of 108 enrolled patients (FAS), 92 (85.2%) completed the study and 57 (52.8%) were included in the per protocol (PP) population. AboBoNT-A improved patient conditions in 96.4% and 98.6% at V2 and V3 (investigator assessment) and 92.8% and 98.6% (as reported by patient) of patients, respectively. Significant reductions in muscle tone from baseline were observed at both visits (p < 0.0001-0.0077) across muscle groups. Increased muscle strength by cumulative MRC was observed at V2 (p = 0.0566) and V3 (p = 0.0282) versus baseline. Safety was consistent with the known profile of aboBoNT-A. In conclusion, aboBoNT-A treatment is beneficial in patients with post-stroke ULS in routine clinical practice, assessed by patients and investigators.