Inclusion Criteria:

• Diagnosis: Recurrent or refractory neuroblastoma or melanoma.
• Age: < 21 years of age at the time of enrollment.
• Does not have a clinically significant neurologic deficit or objective peripheral neuropathy (greater than or equal to grade 2).
• Life expectancy: at least 8 weeks.
• Organ Function: Must have adequate organ and marrow function
• Performance status: Karnofsky > 50 for > 10 years of age; Lansky > 50 for children < 10 years of age (see Appendix III).
• Prior Therapy: Patient must have fully recovered from the acute toxic effects of all prior therapy prior to enrolling on study.
• Myelosuppressive Chemotherapy: Must not have received myelosuppressive therapy within 2 weeks prior to study entry (4 weeks if nitrosurea).
• Biologic (anti-neoplastic agent): At least 7 days since the completion of therapy with biologic agent, including retinoic acid. Participants receiving IVIG are eligible; however, participant must not receive IVIG during the 4 days of antibody infusion.
• Radiation therapy: At least 2 weeks since prior local radiation therapy at the time of study entry.
• Growth factors: Must not have received hematopoietic growth factors (G-CSF, GM-CSF) for at least 1 week prior to study entry.
• Investigational agent: Must not have received investigational agent within 14 days of study entry.
• Immune therapy: Must not have received immunosuppressive (including glucocorticoids), immunostimulatory or any immunomodulatory treatment within 2 weeks of study entry
• Patients may have had prior CNS metastasis providing: CNS disease has been previously treated and CNS disease has been clinically stable for 4 weeks prior to study entry (assessment must be made by CT or MRI).
• Written informed consent following institutional and federal guidelines.

Exclusion Criteria:

• Prior monoclonal antibody: Participants having received in vivo monoclonal antibodies for biologic therapy or for tumor imaging are ineligible unless serologic testing is performed which documents the absence of detectable antibody (over background) to hu14.18.
• Pregnancy or Breast Feeding: Study participants who are pregnant are not eligible for this study. Pregnancy tests must be obtained in girls who are > 10 years of age or post-menarchal within 7 days prior to study enrollment. - - Males or females of reproductive potential may not participate unless they have agreed to use an effective contraceptive method during participation in the trial. Breast feeding should be discontinued if a mother wishes to participate in this study.
• Allergy: known hypersensitivity to other recombinant human antibodies.
• An uncontrolled infection.