Rapid Engraftment and Immune Recovery in Treatment Refractory Severe Aplastic Anemia Patients Undergoing Ex Vivo Nicotinamide-Expanded (Nam-Expanded) Unrelated Cord Blood Transplantation

Introduction. Allogeneic hematopoietic stem cell transplantation using UCB is an alternative approach for pts (pts) with hematological malignancies lacking an HLA matched donor. However, for pts with severe aplastic anemia (SAA), UCB transplants are associated with delayed engraftment, high graft failure rates and poor survival. Ex-vivo expanded UCB using nicotinamide (NAM) can engraft in NOD/SCID mice, and in pilot studies in pts with hematological malignancies, results in rapid engraftment and durable hematopoiesis. Here we investigated a novel transplantation approach using NAM-expanded UCB in refractory SAA pts who lacked an HLA matched donor, hypothesizing this regimen would accelerate engraftment and immune reconstitution compared to conventional UCB transplants.