Efficacy and Safety of Olanzapine in Children Receiving Highly Emetogenic Chemotherapy: A Randomized, Double-blind Placebo-controlled Phase 3 Trial

Background: In this trial, we evaluated the safety and efficacy of olanzapine in children receiving highly emetogenic chemotherapy. Materials and Methods: In this study, patients aged 3 to 18 years were randomly assigned to either the olanzapine group or the placebo group. All patients received intravenous ondansetron and dexamethasone 30 minutes before highly emetogenic chemotherapy, followed by oral ondansetron for 48 hours. Participants in the olanzapine group received olanzapine once daily on days 1 and 2, while those in the control group received a placebo in the same dosage and schedule. The primary objective was: (a) to compare the complete control rates of vomiting in the delayed phase and (b) to compare the complete control rates of vomiting in acute and overall phases. The secondary objective was to evaluate the safety of olanzapine and the need for rescue medications. Results: A total of 128 patients were randomly assigned either to the olanzapine group (n=63) or the control group (n=65). Complete control of vomiting between olanzapine and placebo group was 73% versus 48% (P=0.005) in the delayed phase, 60% versus 54% (P=0.46) in the acute phase, and 48% versus 34% (P=0.117) in the overall phase, respectively. Grades 1 and 2 sedation was greater in the olanzapine group (46% vs. 14%; P<0.001). A significantly higher proportion of patients in the placebo group required rescue medications for vomiting compared with in the olanzapine group (P=0.025). Conclusions: Olanzapine significantly improved complete control of vomiting in the delayed phase. A considerably lesser proportion of patients in the olanzapine group needed rescue medications.

Automated summary

This study evaluated the safety and efficacy of olanzapine in children receiving highly emetogenic chemotherapy. The results showed that olanzapine significantly improved complete control of vomiting in the delayed phase and reduced the need for rescue medications.