Recent advances in novel radioimmunotherapeutic approaches for allogeneic hematopoietic cell transplantation

Allogeneic hematopoietic cell transplantation (HCT) can be a curative treatment for hematologic malignancies and over the last three decades, novel approaches have resulted in significant reductions in morbidity and mortality. Despite current advances, two major limitations remain: patients continue to die from recurrent disease, and rates of nonrelapse mortality are relatively high due to regimen-related organ toxicities. The ability to target therapy with radiolabeled antibodies provides an innovative way to increase the tumoricidal dose of radiation to tumor sites, whereas sparing normal organs, as further dose escalation of chemotherapy and radiotherapy in HCT preparative regimens is not feasible due to dose-limiting toxicities.

This review discusses the most current allogeneic HCT data using radioimmunotherapy (RIT) and focuses on recent trials involving patients at the highest risk for relapse. The results from these studies have shown that standard-dose radiolabeled antibodies can be safely combined with reduced-intensity preparative regimens with encouraging results in a single institution phase II study.

Optimism remains that these RIT approaches will improve the cure rates of allogeneic HCT for the thousands of patients with leukemias and lymphomas who undergo this procedure each year.