Safety & Efficacy of IR-101 in Relapsed/Refractory Neuroblastoma

Inclusion Criteria: 1. Relapsed or refractory high-risk neuroblastoma with MIBG avid lesions in accordance with the Revised International Neuroblastoma Response Criteria (INRC); 2. All soft-tissue lesions detected on CT/MRI must be MIBG-avid; 3. Age ≥12 months; 4. Lansky performance status ≥50%; 5. Adequate organ function and hematologic parameters; Exclusion Criteria: 1. Antibody-based immunotherapy within 5 half-lives or 30 days (whichever is shorter), or not yet recovered from adverse reactions of prior biologic therapies； 2. Treatment with \[¹³¹I\]MIBG or Lu-177 targeted radionuclide therapy \<3 months of last administration; 3. Autologous transplant \<12 weeks, or Allogeneic transplant \<4 months (patients \>4 months post-transplant must be free of active GVHD); 4. Radiotherapy within 2 weeks prior to first dose of study drug (However, if the subjects undergone radiotherapy for the sole lesion have MIBG uptake after 2 weeks of radiotherapy completion, they will be eligible); or Extensive-field radiotherapy (e.g., Cranio-spinal cord, whole lung, whole abdomen, or \>50% bone marrow) within 12 weeks prior to first dose of study drug; 5. Renal Insufficiency; 6. Active Infections;