The goal of this clinical trial is to to assess the efficacy of romiplostim as a supportive care measure in patients with a new diagnosis of Ewing sarcoma receiving interval-compressed chemotherapy. The main questions it aims to answer are: 1. To demonstrate the efficacy of romiplostim in patients with newly diagnosed Ewing sarcoma, measured specifically as the rate of chemotherapy-induced thrombocytopenia (CIT), defined as a failure to achieve platelet recovery. 2. To determine the safety of incorporation of romiplostim supportive care when given concurrently with Ewing sarcoma therapy. 3. To determine the feasibility of incorporation of romiplostim supportive care into upfront Ewing sarcoma regimens