131I-Apamistamab (131I-BC8, Iomab-B™) is an anti-CD45 radioimmunotherapy for the potential treatment of cancer, and in particular AML. The product was initially developed by the Fred Hutchinson Cancer Research Center. The first clinical trials with 131I-BC8 explored the indications acute myeloid leukemia (AML), myelodysplastic syndrome and chronic myelomonocytic leukemia (CML).

31I-BC8 has been successfully used as a myelo-conditioning/myelo-ablative agent in over 250 patients with incurable blood cancers. In Phase I and II trials, 131I-BC8 has led to effective cures in patients with no options left. The priority indication for the company is AML. The targeting part of the 131I-BC8 construct is a murine monoclonal antibody that targets CD45, an antigen widely expressed on hematopoietic cells but not on other tissues. 131I-BC8 could demonstrate utility in other groups of patients and other indications as well, including Myelodysplastic Syndrome, Acute Lymphoblastic Leukemia, Hodgkin’s Disease and Non-Hodgkin’s Lymphoma.

The trial population of the running clinical trial (study SIERRA – Study of Iomab-B in Elderly Relapsed or Refractory AML) includes older relapsed and refractory acute myeloid leukemia patients to be conditioned for a hematopoietic stem cell transplantation (often referred to as bone marrow transplant). There is currently no standard of care and no indication approved drug for these patients. This drug could reach the market by 2022-2023.

Target/Mechanism: CD45

Leading Emitter: beta electrons (β)