AbobotulinumtoxinA: A Review in Pediatric Lower Limb Spasticity.

AbobotulinumtoxinA (Dysport) is currently the only botulinum toxin A formulation approved by the US FDA for the treatment of lower limb spasticity in pediatric patients aged ≥2 years. Intramuscular abobotulinumtoxinA was approved based on the results of a pivotal phase 3 trial in children with lower limb spasticity due to cerebral palsy. In this trial, a single treatment cycle with abobotulinumtoxinA 10-15 U/kg/leg injected into the gastrocnemius and soleus muscles significantly improved ankle plantar flexor muscle tone (primary endpoint), with abobotulinumtoxinA recipients showing a significant response to treatment relative to placebo. AbobotulinumtoxinA treatment also improved spasticity grade. The improvements in muscle tone and spasticity were associated with an improved ability to attain functional goals. Clinical benefits of abobotulinumtoxinA treatment lasted for 16-22 weeks in most patients, and were maintained with multiple treatment cycles during 1 year in an open-label extension study. AbobotulinumtoxinA was generally well tolerated, with a relatively low incidence of treatment-related adverse events. In summary, abobotulinumtoxinA is an effective and generally well tolerated treatment option for children with lower limb spasticity.