Eltrombopag for enhancement of platelet engraftment in patients undergoing allogeneic cord blood transplantation.

Platelet recovery after allogeneic umbilical cord blood (UCB) transplantation is delayed compared to other graft sources. We conducted a multicenter phase 2a study to explore whether eltrombopag, a thrombopoietin-receptor agonist, would enhance platelet recovery after UCB transplantation. Between 02/2013 and 07/2016, 12 (10 adults, 2 children) individuals (median age 50; range 6-74 years) with hematological malignancies in complete remission were enrolled. Eltrombopag was given for a median of 76 (range 15-175) days and was safe even at doses of 300 mg/day. Median time to neutrophil engraftment was 23 (range 16-40) days. Median time to platelets >20,000/µl and >50,000/µl was 55 (range 25-199) and 66 (range 31-230) days, respectively. A historical cohort comparison did not reveal an advantage for eltrombopag. In conclusion, in the present study eltrombopag seems safe. Based on our limited data, it seems unlikely that eltrombopag could enhance platelet engraftment after UCB transplantation.