Adding an Ex Vivo Expanded Cord Blood Unit Improves Engraftment

Patients undergoing cord blood transplantation (CBT) can experience delayed hematopoietic recovery due to the typically smaller cell dose in cord blood units (CBUs), and therefore have a higher increase of post-transplant infections and transplant-related mortality. Co-infusion of a non-HLA matched, ex vivo expanded CBU in addition to an HLA-matched CBU in a transplant recipient is safe, according to research presented at ASH, and can result in significantly more faster hematopoietic recovery: a median of 19 days to neutrophil engraftment compared to historical controls of 25 days.

Researchers in this single-center study reported on 15 cord blood transplant recipients between 2010 and 2012 who were co-infused using this novel technique. The investigators prepared the ex vivo expand cord blood-derived progenitor cells using a Notch ligand-containing culture for 14 days. The product was then harvested and cryopreserved for use in the study.

All patients achieved neutrophil engraftment at a median of 19 days (range, 9-31), which the researchers noted was significantly faster than the 25 days (range, 14-45) observed in 41 recipients in a historical control group (p=0.01). The cumulative incidence of day-100 platelet recovery was significantly higher than that of a concurrent control group: 92% vs. 69%, respectively (p=0.005). No transplant-related mortality was observed throughout the study period, and at a median follow-up of 3.2 years, the 3-year disease-free survival was 86%.

Milano F, et al. Blood