131I-omburtamab for the Treatment of Central Nervous System/Leptomeningeal Neoplasms in Children and Young Adults

Inclusion Criteria: * Patients must have a histologically confirmed diagnosis of an embryonal malignancy (including but not limited to neuroblastoma, medulloblastoma, rhabdoid tumors, pineoblastoma, retinoblastoma, PNET, rhabdomyosarcoma, Ewing's sarcoma, Wilm's tumor, hepatoblastoma) other non-embryonal tumors must have histologic confirmation of B7-H3 reactivity. * Patients must have a diagnosis of CNS/ leptomeningeal disease which has been treated with conventional therapies or for which no conventional therapy exists or a recurrent brain tumor with a predilection for leptomeningeal dissemination (i.e. PNET, rhabdoid tumor). * Chemotherapy: °Patients must have received their last dose of myelosuppressive anticancer therapy at least 21 days (3 weeks) prior to receiving treatment dose(s). * Biologic or investigational agent (anti-neoplastic): * Patients who are currently on biological (small molecule inhibitors such as ALK inhibitors, ROS inhibitors or MEK inhibitors etc.) or investigational agents that are considered non-myelosuppressive can continue treatment but should have recovered from any acute toxicity potentially related to the agent. * Patients may be treated if they received one prior treatment dose with 131I-omburtamab * Monoclonal antibody treatment and agents with known prolonged half-lives: * Patients must have recovered from any acute toxicity potentially related to the agent and received their last dose of the agent ≥ 21 days prior to enrollment.…