Combination Therapy of Antibody Hu3F8 With Granulocyte- Macrophage Colony Stimulating Factor (GM-CSF) in Patients With Relapsed/Refractory High-Risk Neuroblastoma

Ph I: 1 cycle consists of treatment with hu3F8 for 3 days (day 1, 3 \& 5). GM-CSF starts 5 days in advance of each hu3F8 cycle at 250 mcg/m\^2/day (day -4 to day 0), \& at 500 mcg/m\^2/day x 5 days (day 1 to day 5). Hu3F8 cycles are 5 days. Ph II pts may receive treatment on a modified schedule of 3 doses of IV hu3F8 over a maximum of 10 days, as needed. With modified schedules of hu3F8, GM-CSF will be administered at 250 mcg/m2/day x5 days before the 1st dose of hu3F8, as with the standard schedule, but then GM-CSF at 500 mcg/m2/day will be administered on day of the 1st dose of hu3F8, on the day before and on the day of the 2nd dose of hu3F8, and on the day before and on the day of the 3rd dose of hu3F8. Cycles are repeated at 2-4 week intervals between 1st days of hu3F8, through 4 cycles. Pts who complete 4 cycles of treatment w/o complications or disease progression have the option of continuing treatment for up to 24 months from their 1st dose of hu3F8.

As determined by the phase I component of the study, the hu3F8 dosage in the phase II portion is 3 mg/kg/day. Patients who were treated in the phase I component are eligible for treatment in the phase II portion. Cycles are repeated approximately monthly through 5 cycles. Group 1 and Group 3 patients can continue to receive cycles every 1-2 months for up to 24 months from study enrollment or until they receive 5 cycles after a major response (CR or PR) is achieved, whichever comes first. If HAHA becomes (+), cycles are deferred until it becomes (-) again. Patients who develop HAHA which precludes timely treatments with hu3F8+GM-CSF are eligible to receive low-dose maintenance regimens such as irinotecan alone,61 temozolomide alone,62 irinotecan-temozolomide,63 or cyclophosphamide-topotecan.64 They can also receive anti-HAHA agents such as rituximab and cyclophosphamide. They resume treatment with hu3F8+ GM-CSF if HAHA becomes negative. Patients may receive local radiation therapy.