Additional Relevant Details The Phase III registrational study sponsored by Ipsen included 235 pediatric patients (158 received Dysport and 77 received placebo; intent to treat population) and was multicenter, double-blind, prospective, randomized, and placebo-controlled. It was conducted in the U.S., Mexico, Poland, Turkey and France. Patients were randomized (1:1:1) to Dysport® 10 Units/kg/leg, Dysport® 15 Units/kg/leg or placebo injected into the gastrocnemius-soleus muscle complex located in the calf.1 The trial included patients who were botulinum toxin naïve or previously treated with a botulinum toxin more than six months before study entry. The study results showed a statistically significant improvement in mean change from baseline in MAS in ankle plantar flexor muscle tone at both doses of Dysport® versus placebo at Week 4 [LS mean treatment difference vs. placebo were: -0.5 for placebo, -0.9 for Dysport® 10 Units/kg/leg, and -1.0 for Dysport® 15 Units/kg/leg (p<0.05)]. Data at Week 12 as measured by the MAS was also statistically significant [LS mean treatment difference vs. placebo were: -0.5 for placebo, -0.8 for Dysport 10 Units/kg/leg, and -1.0 for Dysport® 15 Units/kg/leg (p<0.05)]. The most common adverse reactions (≥10% of patients in any group and greater than placebo) in pediatric patients with lower limb spasticity for Dysport® 10 Units/kg, 15 Units/kg, 20 Units/kg, or 30 Units/kg; and placebo, respectively, were: upper respiratory tract infection (9%, 20%, 5%, 10%, 13%), nasopharyngitis (9%, 12%,16%, 10%, 5%), influenza (0%, 10%, 14%, 3%, 8%) and pharyngitis (5%, 0%,11%, 3%, 8%), cough (7%, 6%, 14%, 10%, 6%), and pyrexia (7%, 12%, 8%, 7%, 5%). A statistically significant improvement was also observed on the mean PGA response to treatment score at Week 4 [LS mean treatment difference of 0.7 for placebo, 1.5 for Dysport® 10 Units/kg/leg, and 1.5 for Dysport® 15 Units/kg/leg (p<0.05)]. Data at Week 12 as measured by the mean PGA response to treatment score was also statistically significant [LS mean treatment difference vs. placebo were: 0.4 for placebo, 0.8 for Dysport® 10 Units/kg/leg, and 1.0 for Dysport® 15 Units/kg/leg (p<0.05)]. A majority of patients in the clinical study were eligible for retreatment between 16 and 22 weeks; however, some had a longer duration of response. The degree and pattern of muscle spasticity and overall clinical benefit at the time of re-injection may necessitate alterations in the dose of Dysport and muscles to be injected.