Pilot Study of Olanzapine and Aprepitant to Prevent Nausea and Vomiting in Children Receiving Chemotherapy

This will be a pilot study, designed as a randomized, crossover study comparing olanzapine and aprepitant in pediatric oncology patients receiving highly emetogenic chemotherapy (HEC). The primary objective is to determine the feasibility of recruitment and data collection for conducting a larger trial aimed at comparing olanzapine and aprepitant as antiemetic regimens and establishing efficacy of this regimens for pediatric patients receiving HEC. Secondary objectives are to obtain preliminary data regarding the effectiveness of olanzapine and aprepitant as well as the tolerability of olanzapine in the pediatric oncology population. Each patient must be planned to undergo at least 2 cycles of the same cycle of HEC. Each patient will be randomized to receive olanzapine or aprepitant in the first cycle of chemotherapy, and then will receive the other agent in a second cycle of chemotherapy. Patients will also receive ondansetron and dexamethasone with each cycle. Patients with CNS tumors will not receive dexamethasone. Response will be measured objectively recording number of emesis and use of breakthrough medications. The medications chosen for breakthrough medications will be at the treating physicians discretion. A complete response will be no episodes of emesis or use of breakthrough medications. A partial response is one or less episodes of emesis and one or less use of breakthrough medications. Nausea will be measured based on parent and patient scales and will be a separate measure, not included in the compete or partial response.