Efficacy and safety of abobotulinumtoxinA for the treatment of hemiparesis in adults with lower limb spasticity previously treated with botulinum toxin: A secondary analysis of a randomized controlled trial

INTRODUCTION: Efficacy and safety of abobotulinumtoxinA in adults with lower limb spasticity (LLS) are well-established. OBJECTIVE: To examine safety and efficacy of abobotulinumtoxinA in patients previously treated with botulinum toxin type A (BoNT-A) products other than abobotulinumtoxinA. DESIGN: Secondary analysis from a phase 3, double-blind, single-cycle, randomized, placebo-controlled study. SETTING: 52 centers (11 countries). PATIENTS: Adults with spastic hemiparesis were randomized (1:1:1) to receive abobotulinumtoxinA 1000 U, 1500 U or placebo in their affected lower limb. MAIN OUTCOME MEASURE(S): Muscle tone (6-point Modified Ashworth Scale [MAS], 0-5) for the gastrocnemius-soleus complex (GSC); proportion of MAS responders (>/=1 point improvement); angle of catch (XV3 ) and spasticity grade (Y) for GSC and soleus. Assessments were at Weeks 1, 4, and 12 post-injection. Only descriptive statistics are presented. RESULTS: Of 388 patients, 84 received previous BoNT-A treatment (abobotulinumtoxinA 1000 U: N = 30; abobotulinumtoxinA 1500 U: N = 28; placebo: N = 26). At Week 4, mean (SD) changes in MAS score in GSC were - 0.8 (1.1), -0.9 (1.0), and - 0.4 (0.7) for abobotulinumtoxinA 1000 U, 1500 U, and placebo, respectively. Greater MAS responder rates were observed for abobotulinumtoxinA vs placebo at all time points. Mean (SD) changes (Week 4) for aboBoNT-A 1000 U, 1500 U and placebo for XV3 were: GSC, 8 degrees (21), 6 degrees (10) and 1 degrees (7); soleus, 11 degrees (21), 5 degrees (9) and 0 degrees (8), respectively; for Y: GSC, -0.4 (0.7), -0.6 (0.8) and - 0.0 (0.9); soleus, -0.5 (0.7), -0.5 (0.7) and - 0.1 (0.6), respectively. Safety data and adverse events were consistent with the overall known profile of abobotulinumtoxinA. CONCLUSIONS: Patients previously treated with other BoNT-As showed improved muscle tone and spasticity at Week 4 following abobotulinumtoxinA injection vs placebo. These findings suggest abobotulinumtoxinA, at the recommended doses, has a good safety and efficacy profile in adults with LLS previously treated with other BoNT-A products. This article is protected by copyright. All rights reserved.