Neuroblastoma Maintenance Therapy Trial

Inclusion Criteria:

- All patients must have a pathologically confirmed diagnosis of neuroblastoma, < 30.99
years of age and classified as high risk 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.

- All patients must be in complete remission (CR):

1. No evidence of residual disease on scan

2. No evidence of disease metastatic to bone marrow.

- Specific Criteria by Stratum:

Stratum 1: All patients must have completed standard upfront therapy that replicates
treatment which patients who were enrolled on ANBL0032 received, including:

intensive induction chemotherapy and (if feasible) resection of primary tumor, followed by:
consolidation with high-dose chemotherapy with stem cell transplant and radiotherapy,
followed by: immunotherapy with Ch14.18/IL-2/GM-CSF (dinutuximab) and retinoic acid;.

All subjects on Stratum 1 must have also met the following criteria:

• A pre-transplant disease status evaluation that met International Neuroblastoma Response
Criteria (INRC) for CR (complete response), VGPR (very good partial response), or PR
(partial response) for primary site, soft tissue metastases and bone metastases. Patients
who meet those criteria must also meet the protocol-specified criteria for bone marrow
response prior to transplant as outlined below: No more than 10% tumor involvement (based
on total nucleated cellular content) seen on any specimen from a bilateral bone marrow
aspirate/biopsy.

Stratum 2: Neuroblastoma that is in first complete remission following standard upfront
therapy different from that described for Stratum 1.

Stratum 3: Neuroblastoma that failed to have a response of at least PR following induction
chemotherapy and surgical resection of the primary tumor, but that has achieved CR
following additional therapy.

Stratum 4: Patients who have achieved a second or subsequent CR following relapse(s).

- Pre-enrollment tumor survey: Prior to enrollment on this study, a determination of
mandatory disease staging must be performed:

- Tumor imaging studies including

- Bilateral bone marrow aspirates and biopsy

- This disease assessment is required for eligibility and preferably should be done
within 2 weeks prior to enrollment, but must be done within a maximum of 4 weeks
before enrollment.

- Timing from prior therapy:

Stratum 1: Enrollment no later than 60 days after completion of upfront therapy, (last dose
of cis-retinoic acid) with a maximum of 6 cycles of cis-retinoic acid maintenance therapy.

Stratum 2, 3 and 4: Enrollment no later than 60 days from last dose of the most recent
therapy.

- Patients must have a Lansky or Karnofsky Performance Scale score of > 50% and patients
must have a life expectancy of ≥ 2 months.

- All clinical and laboratory studies for organ functions to determine eligibility must
be performed within 7 days prior to enrollment unless otherwise indicated below.

- Patients must have adequate organ functions at the time of registration:

- Hematological: Total absolute phagocyte count ≥1000/μL

- Liver: Subjects must have adequate liver function

- Renal: Adequate renal function

- Females of childbearing potential must have a negative pregnancy test. Patients of
childbearing potential must agree to use an effective birth control method. Female
patients who are lactating must agree to stop breast-feeding.

- Written informed consent in accordance with institutional and FDA (food and drug
administration) guidelines must be obtained from all subjects (or patients' legal
representative).

Exclusion Criteria:

- BSA (Body Surface Area) of <0.25 m2.

- Investigational Drugs: Subjects who are currently receiving another investigational
drug are excluded from participation.

- Anti-cancer Agents: Subjects who are currently receiving other anticancer agents are
not eligible. Subjects must have fully recovered from hematological and bone marrow
suppression effects of prior chemotherapy.

- Infection: Subjects who have an uncontrolled infection are not eligible until the
infection is judged to be well controlled in the opinion of the investigator.

- Subjects who, in the opinion of the investigator, may not be able to comply with the
safety monitoring requirements of the study, or in whom compliance is likely to be
suboptimal, should be excluded.