Pediatric Malignant Solid Tumor and Epithelioid Sarcoma

This is a multicenter, open-label, uncontrolled Phase I/II study to evaluate the efficacy, safety, and pharmacokinetics of ONO-4538HSC in pediatric patients with malignant solid tumors and in patients with epithelioid sarcoma, and to evaluate the tolerability in pediatric patients. The objective of this study is to explore the tolerability, safety, efficacy, and pharmacokinetics of ONO-4538HSC in patients with pediatric malignant solid tumors. The other objective is to exploratively investigate the efficacy and safety of ONO-4538HSC in patients with epithelioid sarcoma.