This study involves an investigational cellular therapy called Afamitresgene Autoleucel. The overall goal of this study is to find out how safe and effective this cellular therapy is in treating people that have been diagnosed with synovial sarcoma, malignant peripheral nerve sheath tumors (MPNST), neuroblastoma or osteosarcoma that has grown or returned after being treated.

This study is looking to recruit CHOP patients 5-30 years old with suspected/ confirmed bone sarcomas. The study is looking to evaluate a new MRI technique to evaluate bones and any mass in them. The study involved an additional imaging sequence performed at the same day as your clinically indicated MRI studies that allows researchers to better visualize the bones. This sequence takes about 30-60 minutes and may be done each time you have a clinically-indicated MRI (up to 3 times). If you're interested in learning more, please contact the study team.

This study has two parts. Part A enrolls patients who have been diagnosed with a solid tumor, lymphoma or desmoid tumor that has either come back ("relapsed") or does not respond to therapy ("is refractory"). Part B enrolls patients with a relapsed or refractory Ewing sarcoma, desmoid tumor, osteosarcoma, liver tumor, Wilms tumor, or tumors with changes in a gene family known as the Wnt pathway. This study involves taking a study drug called tegavivint. The study will be testing different doses of the study drug to find the safest dose.