Winner PK, Kabbouche M, Yonker M, et al. - Researchers performed this dose-ranging study as a postapproval commitment for estimating the efficacy and safety of onabotulinumtoxinA in adolescents. A single treatment of onabotulinumtoxinA (155 U or 74 U) or placebo (intramuscular saline) was administered via the recommended fixed-dose fixed-site paradigm to adolescents with chronic migraine aged 12 to < 18 years in this multicenter, double-blind, parallel-group, randomized trial. Change in the frequency of headache days from baseline at week 12 was determined as the primary efficacy measure; other measures incorporated change in frequency of headache days at weeks 4 and 8 and change in frequency of severe headache days. They randomized 125 patients (onabotulinumtoxinA 155 U, n = 45; onabotulinumtoxinA 74 U, n = 43; placebo, n = 37), of these, 15 (92.0%) completed the study. Discontinuation was observed mainly in relation to lack of efficacy (n = 4; 3.2%); adverse events did not lead to any discontinuation. The frequency of headache days reduced at week 12 with all treatments; no significant differences between treatments were observed. All treatments led to a decrease in the frequency of severe headache days and were well-tolerated. They observed the occurrence of serious adverse events (n = 3) that were considered unrelated to treatment and resolved without sequelae. Neck pain (n = 8), upper respiratory tract infection (n = 7), migraine, and nasopharyngitis (n = 5 each) were the most commonly reported treatment-emergent adverse events. Although its efficacy endpoints were not met, the adolescent population well-tolerated onabotulinumtoxinA.