GPC3 CAR T Cells With IL-15 and IL-21 for Recurrent ATRT and CNS Rhabdoid Tumors (RADIANT)

Procurement Inclusion Criteria: * 1\) Diagnosis of GPC3-positive recurrent ATRT. * 2\) Age ≥ 6 months * 3\) Karnofsky/Lansky score ≥ 60% * 4\) Informed consent explained to, understood by, and signed by patient/guardian; copy provided * 5\) GPC3 expression by immunohistochemistry with extent score ≥ Grade 2 (\>25% positive tumor cells) and intensity score ≥ 2 (scale 0-4) Procurement Exclusion Criteria: * 1\) No history of organ transplantation * 2\) No known HIV positivity * 3\) No active bacterial, fungal, or viral infection (except Hepatitis B or Hepatitis C virus infections) * 4\) No other risk factors in which administration of the investigational agent is deemed not in the patient's best interest, in the opinion of the investigator Treatment Inclusion Criteria: * 1\) Age ≥ 6 months * 2\) Diagnosis of treatment refractory or unresectable ATRT after standard of care therapy * 3\) Lansky/Karnofsky score ≥ 60% * 4\) Stable neurologic exam for 7 days prior to enrollment * 5\) Stable or decreasing dose of steroids over past 7 days prior to surgery and administration of therapy (max allowable dose is 0.1mg/kg dexamethasone or equivalent per day) * 6\) Not receiving any concurrent anti-cancer therapy. * 7\) At least 6 weeks following craniospinal radiation therapy. * 8\) At least 14 days wash-out needed following small volume radiotherapy (i.e., Stereotactic Radiosurgery (SRS)). * 9\) At least 21 days or 5 half-lives (whichever is shorter) must have elapsed since any prior …