Recombinant human thrombopoietin promotes platelet engraftment after umbilical cord blood transplantation

Delayed platelet engraftment is a common complication after umbilical cord blood transplantation (UCBT) accompanied by increased transplant-related complications or death. This study was designed to determine the safety and efficacy of recombinant human thrombopoietin (rhTPO) in promoting platelet engraftment after UCBT. A total of 120 patients scheduled to receive UCBT were randomly assigned to the rhTPO group (300 U/kg once daily from days 14 to 28 after UCBT, n = 60) or the control group (n = 60). The primary outcome was the 60-day cumulative incidence of platelet engraftment after single-unit cord blood transplantation. The 60-day cumulative incidence of platelet engraftment (platelet count >20 x 10(9)/L) and the 120-day cumulative incidence of platelet recovery (platelet count >50 x 10(9)/L) were both significantly higher in the rhTPO group than in the control group (83.1% vs 66.7%, P - .020; and 81.4% vs 65.0%, P - .032, respectively). In addition, the number of required platelet infusions was significantly lower in the rhTPO group than in the control group (6 vs 8 units, respectively; P = .026). The cumulative incidence of neutrophil engraftment and the probability of 2-year overall survival, disease-free survival, and graftversus-host disease-free relapse-free survival did not differ between the 2 groups. Other transplant-related outcomes and complications did not differ between the 2 groups, and no severe adverse effects were observed in patients receiving rhTPO. This study demonstrated that rhTPO is well tolerated in patients and could effectively promote platelet engraftment after UCBT.