Efficacy and Safety of AbobotulinumtoxinA (Dysport) for the Treatment of Hemiparesis in Adults With Upper Limb Spasticity Previously Treated With Botulinum Toxin: Subanalysis From a Phase 3 Randomized Controlled Trial

<jats:title>Abstract</jats:title><jats:sec><jats:title>Objective</jats:title><jats:p>To assess the efficacy and safety of abobotulinumtoxinA in adults with upper limb spasticity previously treated with botulinum toxin A (BoNT‐A).</jats:p></jats:sec><jats:sec><jats:title>Design</jats:title><jats:p>A post hoc analysis from a Phase 3, prospective, double‐blind, randomized, placebo‐controlled study (<jats:ext-link xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="ctgov:NCT01313299">NCT01313299</jats:ext-link>).</jats:p></jats:sec><jats:sec><jats:title>Setting</jats:title><jats:p>A total of 34 neurology or rehabilitation clinics in 9 countries.</jats:p></jats:sec><jats:sec><jats:title>Participants</jats:title><jats:p>Adults aged 18‐80 years with hemiparesis, ≥6 months after stroke or traumatic brain injury. This analysis focused on a subgroup of subjects with previous onabotulinumtoxinA or incobotulinumtoxinA treatment (n = 105 of 243 in the total trial population) in the affected limb. The mean age was 52 years, and 62% were male.</jats:p></jats:sec><jats:sec><jats:title>Intervention</jats:title><jats:p>Study subjects were randomized 1:1:1 to receive a single injection session with abobotulinumtoxinA 500 or 1000 U or with placebo in the most hypertonic muscle group among the elbow, wrist, or finger flexors (primary target muscle group [PTMG]), and ≥2 additional muscle groups from the upper limb.</jats:p></jats:sec><jats:sec><jats:title>Main Outcome Measurements</jats:title><jats:p>Efficacy and safety measures were assessed, including muscle tone (Modified Ashworth Scale [MAS] in the PTMG), Physician Global Assessment (PGA), perceived function, spasticity, active movement, and treatment‐emergent adverse events.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>At week 4, more subjects had ≥1 grade improvement in MAS for the PTMG with abobotulinumtoxinA versus placebo (abobotulinumtoxinA 500 U, 81.1%; abobotulinumtoxinA 1000 U, 75.0%; placebo, 25.0%). PGA scores ≥1 were achieved by 75.7% and 87.5% of abobotulinumtoxinA 500 and 1000 U subjects versus 41.7% with placebo. Perceived function (Disability Assessment Scale), spasticity angle (Tardieu Scale), and active movement were also improved with abobotulinumtoxinA. There were no treatment‐related deaths or serious adverse events.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>The efficacy and safety of abobotulinumtoxinA in subjects previously treated with BoNT‐A were consistent with those in the total trial population. Hence, abobotulinumtoxinA is a treatment option in these patients, and no difference in initial dosing appears to be required compared to that in individuals not treated previously.</jats:p></jats:sec><jats:sec><jats:title>Level of Evidence</jats:title><jats:p>III</jats:p></jats:sec>