67Cu-SARTATE™ Peptide Receptor Radionuclide Therapy Administered to Pediatric Patients With High-Risk, Relapsed, Refractory Neuroblastoma

Inclusion Criteria: 1. Participant is able and willing to provide informed consent (≥18 years), or informed consent is obtained by the parent or legal guardian for minor participants, with the minor providing age appropriate assent, according to local law and regulations; 2. Life expectancy ≥ 12 weeks for patients in the Dose Escalation Phase or ≥ 4 months for patients in the Cohort Expansion Phase; 3. Known high-risk neuroblastoma OR previously intermediate-risk neuroblastoma that has relapsed or progressed to high-risk, with failure to achieve complete response with standard therapy (defined as at least 4 cycles of aggressive multi-drug induction chemotherapy with or without radiation and surgery, or according to a standard high-risk treatment/neuroblastoma protocol), OR who are medically ineligible to receive standard treatment OR who are intolerant to standard treatment; 4. Adequate recovery from acute toxic effects of any prior therapy, as deemed by the Investigator or treating Sub-Investigator; 5. Adequate liver function as defined by the following laboratory values obtained within 28 days prior to administration of 64Cu-SARTATE: Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) \< 3.0 x upper limit of normal (ULN); 6. Adequate renal function; 7. Adequate laboratory parameters: Absolute neutrophil count \> 1.0 x 10 9/L; Platelet count \> 50 x 10 9/L; Total bilirubin \<1.5 x ULN; 8. Karnofsky or Lansky performance status ≥50; 9. All participants must have a hematopoietic stem cell product available (minimum CD34+ cell dose is ≥2 x 10 6 cells/kg); 10. Sexually active participants of reproductive potential must practice an effective method of birth control while participating on this study, to avoid possible damage to the fetus. Abstinence is considered acceptable; 11. 64Cu-SARTATE uptake on the 4 hour scan (SUVmax) of any lesion equal to or higher than that of the liver in order to move on to the therapy phase of the study. Exclusion Criteria: 1. Participants with disease of any major organ system that would compromise their ability to tolerate therapy, as deemed by the Investigator or treating Sub-Investigator; 2. Participants with intracranial tumor affecting the brain parenchyma that has not been previously treated at the time of study enrolment; 3. Any other active malignancy, or a history of prior malignancy within the past 3 years; 4. History of cardiac failure as evidenced by: dyspnea at rest, exercise intolerance, oxygen requirement, clinically significant cardiac dysfunction; 5. Planned administration of chemotherapy, anti-cancer cytokine therapy, immunotherapy or radiotherapy within 2 weeks prior to the administration of 64Cu-SARTATE; 6. Administration of therapeutic dose of 131I-MIBG within 8 weeks prior to the administration of 64Cu-SARTATE; 7. External beam radiation therapy (EBRT) to both kidneys or a single functioning kidney within 12 months prior to the administration of 64Cu-SARTATE; 8. Administration of any investigational agents within 21 days prior to administration of 64Cu-SARTATE; 9. Treatment with long acting somatostatin analogues (administered within 28 days prior to the administration of 64Cu-SARTATE), or short acting somatostatin analogues (administered within 24 hours prior to the administration of 64Cu-SARTATE); 10. Known sensitivity or allergy to somatostatin analogues; 11. Previous peptide receptor radionuclide therapy (PRRT); 12. Female participants who are pregnant or lactating; 13. Participants who are on hemodialysis; 14. QTcF interval ≥ 0.45 seconds as measured by Screening ECG; 15. Participants with uncontrolled infection(s); 16. Any medical condition which the Investigator feels may interfere with the procedures or evaluations of the study; 17. Participants 12 months and younger will be excluded from cohorts where the planned single or cumulative administered activity is modelled to deliver a radiation dose to the marrow that exceeds 2 Gy.