Pilot Trial of Eltrombopag in Patients Undergoing Chemotherapy for Malignant Solid Tumors

Primary Objective: To assess safety of eltrombopag in pediatric patients undergoing intensive chemotherapy for malignant solid tumors. Secondary Objectives: To assess the efficacy of eltrombopag in increasing platelet count up to 2 weeks after completion of chemotherapy in pediatric patients undergoing intensive chemotherapy for malignant solid tumors. Hypothesis: The hypothesis is that eltrombopag an oral thrombopoietin receptor agonist will increase the platelet count safely and efficaciously in children having chemotherapy induced thrombocytopenia while on therapy for solid tumors.