The goal of this research study is to test if a new cell therapy (B7-H3.CD28Z.CART / B7-H3 CAR T cells) is safe and effective in treating children and young adults with solid cancers whose tumors have returned or stopped responding to standard treatments (relapsed or refractory) and have been identified with a B7-H3 marker.
The names of the treatment interventions used in this study are:
* B7-H3.CD28Z.CART / B7-H3 CAR T cells
* Fludarabine
* Cyclophosphamide