In this final analysis of a phase 3 , randomised , multicentre , double-blind study , patients aged 6 months to 17 years with a documented malignancy who were scheduled to receive either moderately or highly emetogenic chemotherapy were randomly assigned with an interactive voice response system to an age-based and weight-based blinded regimen of aprepitant ( 125 mg for ages 12-17 years ; 30 mg/kg up to 125 mg for ages 6 months to < 12 years ) plus ondansetron on day 1 , followed by aprepitant ( 80 mg for ages 12-17 years ; 20 mg/kg up to 80 mg for ages 6 months to < 12 years ) on days 2 and 3 , or placebo plus ondansetron on day 1 followed by placebo on days 2 and 3 ; addition of dexamethasone was allowed .