FSK0808, a biosimilar of filgrastim, is a recombinant human granulocyte colony-stimulating factor developed by Fuji Pharmaceuticals and Mochida Pharmaceutical Co., Ltd. We conducted a double-blind, randomized, crossover study in healthy Japanese men, comparing the number of CD34-positive cells (CD34(+) cells) after repeated subcutaneous administration of either FSK0808 or the reference filgrastim (Gran(®) ). As primary endpoints, we compared the maximum number of CD34(+) cells (CD34(+) Cmax ) and the time to reach CD34(+) Cmax (CD34(+) tmax ). As secondary endpoints, we compared the area under the curve for the number of CD34(+) cells over time at the 410 hours time point (CD34(+) AUC0-410 ), the parameters used to calculate the pharmacodynamic index of the absolute neutrophil count, and the pharmacokinetic parameters. Regarding the CD34(+) Cmax and the CD34(+) AUC0-410 values, the 95% confidence interval (CI) of the differences between the mean values for each drug was within the range of log(0.8)-log(1.25). With respect to the differences in the median values between drugs, the ratio against the reference filgrastim median value in the 95% CI was within the range of ± 0.2 for the CD34(+) tmax value. From these results, we considered that these drugs display equivalent pharmacodynamic and pharmacokinetic properties.
© 2015, The American College of Clinical Pharmacology.