Comparable pharmacokinetics and pharmacodynamics of two epoetin alfa formulations Eporon ® and Eprex ® following a single subcutaneous administration in healthy male volunteers.

Purpose: This study aimed to assess and compare the pharmacokinetic (PK) and pharmacodynamic (PD) properties following a single subcutaneous injection of epoetin alfa (Eporon® ) with those of the comparator (Eprex® ) in healthy male subjects.

Subjects and methods: A randomized, double-blind, two-sequence, crossover study was conducted. Subjects were randomly assigned to receive a single dose, that is, 4,000 IU, of the test or comparator epoetin alfa. After 4 weeks, all subjects received the alternative formulation. The primary PK parameters, maximum observed concentration (Cmax ) and area under the curve extrapolated to infinity (AUCinf ), were calculated with the serum erythropoietin (EPO) concentrations from blood samples collected for 144 h after dosing. The reticulocyte, hematocrit, hemoglobin and red blood cell counts were measured up to 312 h as PD markers. The primary PD parameters, maximum observed effect (Emax ) and area under the effect curve (AUEC), were obtained from the baseline-corrected reticulocyte count. The serum EPO concentration and the reticulocyte count were used to assess the concentration-response relationship. The tolerability and immunogenicity profiles were assessed together.

Results: Forty-two subjects completed the study. The mean EPO concentration-time profiles were comparable between the two formulations. The geometric mean ratios (90% CI) of the Cmax and AUCinf were 0.908 (0.843-0.978) and 1.049 (0.999-1.101), respectively, both of which were within the regulatory range of 0.80-1.25. Additionally, the PD and tolerability profiles were similar between the two formulations. The time-matched serum EPO concentration and PD markers presented a counterclockwise hysteresis, suggesting a time delay between the measured concentration and the response. Both formulations were well tolerated, and production of anti-drug antibodies was not observed.

Conclusion: The two epoetin alfa formulations had similar PK, PD and tolerability profiles. Furthermore, both formulations had a similar time-matched serum EPO concentration and erythropoietic response profile. Thus, the two formulations are expected to be used interchangeably in clinical settings.