Safety & Efficacy of IR-101 in Relapsed/Refractory Neuroblastoma

This study is testing the safety and effectiveness of a new drug called IR-101 in children and young patients with high-risk neuroblastoma (a childhood cancer affecting nerve tissue) that has come back or stopped responding to previous treatment, and whose tumors are detectable on a special scan called MIBG. **You may be eligible if...** - You have relapsed or refractory high-risk neuroblastoma - Your tumors are visible on MIBG (a special nuclear medicine scan) - You are at least 12 months old - Your functional status and organ function meet the required thresholds **You may NOT be eligible if...** - You recently received certain antibody-based therapies or MIBG-based radiation treatments - You recently had a stem cell transplant - You recently completed radiation therapy to most of the body - You have significant kidney problems or active infections Talk to your doctor to see if this trial is right for you.