Safety Study for Refractory or Relapsed Neuroblastoma With DFMO Alone and in Combination With Etoposide

The purpose of this research study is to evaluate a new investigational drug to treat neuroblastoma. This study drug is called DFMO. The objectives of this study will be to monitor for safety and to find a maximum tolerated dose in this population. A secondary objective will be to look at efficacy of DFMO. The safety of the proposed dosing regimen in this trial will be tested by an on-going risk/benefit assessment during the study. A patient benefiting from treatment, not progressing on therapy, and in the absence of any safety issues associated with DFMO and/or etoposide may continue on treatment with the expectation that there will be an overall clinical benefit. The procedures involved in this study include Medical history, Physical exam, Vital signs (blood pressure, pulse, temperature), Blood tests, Urine tests, MRI or CT scan of the tumor(s), MIBG scans, and Bone marrow aspirations. All of these tests and procedures are considered standard of care for this population. Drug administration is also part of this protocol, including an investigational new drug called DFMO, and later combined with an already approved drug, etoposide. The proposed dosing regimen is an oral dose of DFMO two times a day for each day while on study. There will be 5 cycles. Each cycle will be 21 days in length. The first cycle will be DFMO alone. In the second cycle etoposide will be added in and will be given orally once a day for the first 14 days of each cycle (cycles 2-5).