• Part A- CLOSED:

• Diagnosis: Subjects must have a diagnosis of neuroblastoma or ganglioneuroblastoma (nodular or intermixed) verified by histology or demonstration of clumps of tumor cells in bone marrow with elevated urinary catecholamine metabolites. Subjects with the following disease stages at diagnosis are eligible, if they meet the other specified criteria:

• a) Subjects with newly diagnosed neuroblastoma with INSS Stage 4 are eligible with the following: i. Age \> 18 months (\> 547 days) regardless of biologic features or ii. Age 12-18 months (365-547 days) with any of the following 3 unfavorable biologic features (MYCN amplification, unfavorable pathology and/or DNA index = 1) or iii. MYCN amplification (\> 4-fold increase in MYCN signals as compared to reference signals), regardless of age or additional biologic features.

• b) Subjects with newly diagnosed neuroblastoma with INSS Stage 3 are eligible with the following: i. MYCN amplification (\> 4-fold increase in MYCN signals as compared to reference signals), regardless of age or additional biologic features or ii. Age \> 18 months (\> 547 days) with unfavorable pathology, regardless of MYCN status.

• c) Subjects with newly diagnosed neuroblastoma with INSS Stage 2A/2B with MYCN amplification (\> 4-fold increase in MYCN signals as compared to reference signals), regardless of age or additional biologic features.

• Subjects must be age ≤ 21 years at initial diagnosis

• Subjects must not have had prior systemic therapy except for localized emergency radiation to sites of life-threatening or function-threatening disease and/or no more than 1 cycle of chemotherapy per a low or intermediate risk neuroblastoma regimen (as per P9641, A3961, ANBL0531, or similar) prior to determination of MYCN amplification status and histology.

• Specimens will be obtained only in a non-significant risk manner and not solely for the purpose of investigational testing.

• Ability to tolerate PBSC collection: No known contraindication to PBSC collection. Examples of contraindications would include a weight or size less than that determined to be feasible at the collecting institution, or a physical condition that would limit the ability of the child to undergo apheresis catheter placement (if necessary) and/or the apheresis procedure.

• Part A and B both- Part A CLOSED, Part B- OPEN:

• Adequate Cardiac Function Defined As:

∙ Shortening fraction of ≥ 27% by echocardiogram, or

‣ Ejection fraction of ≥ 50% by radionuclide evaluation or echocardiogram.

• Adequate liver function must be demonstrated, defined as:

• c. Total bilirubin ≤ 1.5 x upper limit of normal (ULN) for age AND d. ALT (SGPT) \< 10 x upper limit of normal (ULN) for age

• Subjects must have adequate renal function defined as a serum creatinine based on age/gender as follows:

• Age Maximum Serum Creatinine (mg/dL) Male Female 1 month to \< 6 months 0.4 0.4 6 months to \< 1 year 0.5 0.5 1 to \< 2 years 0.6 0.6 2 to \< 6 year 0.8 0.8 6 to \< 10 years 1 1 10 to \< 13 years 1.2 1.2 13 to \< 16 years 1.5 1.4

• ≥ 16 years 1.7 1.4

• A negative serum pregnancy test is required for female participants of child bearing potential (≥13 years of age or after onset of menses)

⁃ Both male and female post-pubertal study subjects need to agree to use one of the more effective birth control methods during treatment and for six months after treatment is stopped. These methods include total abstinence (no sex), oral contraceptives (the pill), an intrauterine device (IUD), levonorgestrol implants (Norplant), or medroxyprogesterone acetate injections (Depo-provera shots). If one of these cannot be used, contraceptive foam with a condom is recommended.

⁃ Informed Consent: All subjects and/or legal guardians must sign informed written consent. Assent, when appropriate, will be obtained according to institutional guidelines.

⁃ Part B- OPEN:

⁃ All patients must have a pathologically confirmed diagnosis of neuroblastoma, be age ≤ 21 years at initial diagnosis, and classified as high risk by the criteria used by COG or SIOPEN at the time of diagnosis. Exception: patients who are initially diagnosed as non-high-risk neuroblastoma, but later converted (and/or relapsed) to high risk neuroblastoma are also eligible.

⁃ Previous Therapy- subjects must fit into one of the strata categories listed in section 10.5 to be eligible to enroll on Part B of this study.

⁃ Pre-enrollment tumor survey:

⁃ Prior to enrollment on Part B, a determination of mandatory disease staging must be performed. Tumor imaging studies including CT or MRI, MIBG or PET, and VMA/HVA (PET scan should be done for patients with prior disease that was MIBG non-avid). Bone marrow aspirates and biopsies are required.

⁃ This disease assessment is required for eligibility and should be done preferably within 2 weeks, but must be done within a maximum of 4 weeks before first dose of study drug.

⁃ Timing- Enrollment to occur prior to Day + 120 post-transplant, preferably when the subject is within 28 days after completing local radiation therapy (if given).