Autologous B7-H3 Chimeric Antigen Receptor T Cells in Relapsed/Refractory Solid Tumors

This study tests a new type of cancer immunotherapy called B7-H3 CAR-T cell therapy — where a patient's own immune cells are genetically modified to find and attack solid tumors — in children and young adults with relapsed or treatment-resistant solid tumors. **You may be eligible if...** - You are between 2 and 30 years old (the first three patients must be 12–30) - You have a confirmed solid tumor such as neuroblastoma, soft tissue sarcoma, osteosarcoma, Ewing sarcoma, or Wilms tumor - Your cancer has come back or is not responding to standard treatments - Your tumor tissue is available for testing (or you are willing to have a biopsy) - You have reasonable blood counts, kidney, liver, and heart function **You may NOT be eligible if...** - You are currently in another clinical trial - You have untreated brain tumors (treated and stable ones may be acceptable) - You have an active, uncontrolled infection - You have HIV, active hepatitis B or C - You have had a serious heart event in the past 12 months - You have an autoimmune condition requiring immune-suppressing medication - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.