Testing the Combination of Two Immunotherapy Drugs (Magrolimab and Dinutuximab) in Patients With Relapsed or Refractory Neuroblastoma or Relapsed Osteosarcoma

This phase I trial is to find out the best dose, possible benefits and/or side effects of magrolimab in combination with dinutuximab in treating patients with neuroblastoma that has come back (relapsed) or does not respond to treatment (refractory) or relapsed osteosarcoma. Magrolimab and dinutuximab are monoclonal antibodies that may interfere with the ability of tumor cells to grow and spread. The combination of magrolimab and dinutuximab may shrink or stabilize relapsed or refractory neuroblastoma or relapsed osteosarcoma. In addition, this trial may help researchers find out if it is safe to give magrolimab and dinutuximab after surgery to remove tumors from the lungs.