Clinical Design and Objectives

This Phase 1/2 trial evaluates a radioconjugate therapy combining a radioactive isotope (211At) with an antibody (BC8-B10), followed by donor hematopoietic stem cell transplantation in patients with high-risk acute leukemia and myelodysplastic syndromes. The primary objective is to determine safety and the optimal dose, while the secondary objective is to explore early efficacy signals. Patients are enrolled only if they have relapsed or are refractory to prior treatments.

Differentiation from Existing Treatments

The current standard of care involves high-dose chemotherapy and total body irradiation (TBI) followed by hematopoietic stem cell transplantation, but this approach carries a high risk of relapse and persistent toxicity. 211At-BC8-B10 is a targeted radiation therapy where the radioactive isotope is conjugated to an antibody, delivering radiation directly to cancer cells. This approach aims to selectively destroy tumor cells while minimizing damage to normal tissues, potentially reducing the side effects associated with conventional non-targeted radiation and chemotherapy.

Clinical Progress and Expected Outcomes

The trial is currently in the recruitment phase and began in July 2019. If successful dose escalation and safety are demonstrated, the study may be expanded into a randomized controlled trial. Positive efficacy results could establish radioconjugate therapy as a new treatment paradigm in high-risk leukemia.

Industrial and Research Impact

This research provides scientific evidence for the development of antibody-radionuclide conjugates (radioimmunoconjugates) and may open the door to applications in other hematological malignancies and solid tumors. Furthermore, it will provide valuable data on how pre-transplant targeted radiation therapy affects engraftment rates and the risk of graft-versus-host disease (GVHD).