Total Body Irradiation and Astatine-211-Labeled BC8-B10 Monoclonal Antibody for the Treatment of Nonmalignant Diseases

This phase I/II trial studies the best dose of total body irradiation with astatine-211 BC8-B10 monoclonal antibody for the treatment of patients with nonmalignant diseases undergoing hematopoietic cell transplant. Radiation therapy uses high energy gamma rays to kill cancer cells and shrink tumors. Astatine-211-labeled BC8-B10 monoclonal antibody is a monoclonal antibody, called anti-CD45 monoclonal antibody BC8-B10, linked to a radioactive/toxic agent called astatine 211. Anti-CD45 monoclonal antibody BC8-B10 is attached to CD45 antigen positive cancer cells in a targeted way and delivers astatine 211 to kill them. Giving astatine-211 BC8-B10 monoclonal antibody and total-body irradiation before a donor stem cell transplant may help stop the growth of cells in the bone marrow, including normal blood-forming cells (stem cells) and cancer cells. It may also stop the patient's immune system from rejecting the donor's stem cells.

OUTLINE: Patients receive astatine At 211 anti-CD45 monoclonal antibody BC8-B10 intravenously (IV) on any day between days -10 and -7, fludarabine IV on days -6 to -2, cyclophosphamide IV over 1 hour on days -6 to -5 and 3 to 4, and thymoglobulin IV over 4-6 hours on days -4 to -2. Patients undergo TBI on day -1 and hematopoietic cell transplant on day 0. Beginning day 5, patients also receive mycophenolate mofetil orally (PO) or IV thrice daily every 8 hours up to day 35 if no GVHD present and sirolimus PO daily until day 365. Patients undergo blood sample collection and may undergo bone marrow aspiration throughout the study. After completion of study treatment, patients are followed up at 1 and 2 years and then periodically for up to 5 years. Note: National Heart, Lung, and Blood Institute (NHLBI) funding for this study ended in 2022.