MIBG Therapy for Patients With MIBG Avid Tumors

This is a Phase II study for patients with MIBG avid tumors. The study is to determine the response rate to \<131\>I-MIBG in patients with de novo, relapsed or refractory neuroblastoma or other MIBG avid malignant tumors 42 days post MIBG therapy. It will also be evaluating the tolerability and safety of the study agent by evaluating the hematopoietic and non-hematopoietic toxicity of \<131\>I-MIBG therapy. Tumor response will be evaluated by comparing the patient's disease pre-treatment against the patient's day +42 post \<131\>I-MIBG treatment. The evaluations may include the following: \<131\>I-MIBG scan, CT or MRI, urine catecholamine, bone marrow analyses and any other tests considered standard of care for cancer evaluation. To be eligible for participation, patients must have tumors that are MIBG avid. Patients must also have a stem cell source for autologous rescue in the event of protracted therapy associated cytopenias. Peripheral stem cell collections are preferred as the hematopoietic cell source. Bone marrow harvests for a hematopoietic cell source is an alternative. This study will provide data for future clinical trials utilizing \<131\>I-MIBG therapies. A room on H12 has been prepared with lead lined walls, and many radiation safety components to accomodate this treatment. \<131\>I metaiodobenzlguanidine (\<131\>I-MIBG) is a radiopharmaceutical that concentrates within adrenomedullary tissue. The agent was initially used for tumor imaging due to its capability to locate pheochromocytomas, neuroblastomas and other neuroendocrine tumors. \<131\>I-MIBG was subsequently used as an therapeutic agent for these tumor types. Phase I and II therapeutic trials targeting neuroblastoma have reported response rates of 10-50%. Toxicities observed have been mainly hematopoietic, with \~50% of patients receiving 15mCi/kg requiring stem cell reinfusion. Observed non-hematopoietic toxicities have been mild. Most recently, trials have been conducted combining the study agent with myeloablative chemotherapy and stem cell reinfusion have been performed with initial response rates of \~50%.