A Randomized Controlled Trial to Compare Once- versus Twice-Daily Filgrastim for Mobilization of Peripheral Blood Stem Cells from Healthy Donors

Although the mobilization of peripheral blood stem cells from normal donors using granulocyte colony-stimulating factor is widely used, the ideal method for the administration of filgrastim has not been determined. Therefore, we compared the efficacy of peripheral blood stem cell mobilization on day 4 of filgrastim between once-daily (group O) and twice-daily (group T) administration of filgrastim at 400 μg/m2/d. In all, 38 and 34 donors were randomly assigned to groups O and T, respectively. The number of CD34+ cells collected on day 4 was not significantly different (1.74 × 106 cells/kg in group O and 2.08 × 106 cells/kg in group T, P = .37). The incidence and severity of adverse events were similar in the two groups. The baseline white blood cell count was the strongest predictor of poor mobilization. Donor age, sex, and serum concentrations of several cytokines did not significantly affect the CD34+ cell yield. In conclusion, once-daily administration of filgrastim at 400 μg/m2/d appeared to be appropriate for the mobilization of CD34+ cells in normal donors when apheresis is planned on day 4 of filgrastim. Selection of a donor with a steady-state white blood cell count of 5.0 × 109/L or more may lead to a lower incidence of poor mobilization.