Recombinant filgrastim (BK0023) pharmacodynamics and pharmacokinetics after single and multiple escalating doses in an equivalence study in healthy men.

BACKGROUND AND OBJECTIVES: The new filgrastim formulation, BK0023, whose synthesis method is patented, was tested in a phase I clinical study that was aimed at investigating the pharmacodynamic and pharmacokinetic equivalence and the safety of BK0023 in healthy male subjects. METHODS: Single and multiple escalating doses were administered to healthy male volunteers according to a double-blind, randomised, two-way crossover design. Thirty-two subjects received subcutaneous filgrastim 2.5 µg/kg/day for 7 consecutive days in each period, 36 subjects received 5 µg/kg/day for 7 days in each period, and 22 subjects received 10 µg/kg/day for 5 days. Absolute neutrophil count (ANC) and CD34+ cell count were measured in whole blood as primary and secondary pharmacodynamic parameters. Filgrastim concentrations were measured in serum to calculate the primary pharmacokinetic parameters. RESULTS: The maximum ANC and the area under the curve of the ANC after the first dose and to the end of treatment satisfied the equivalence criterion (95 % confidence intervals within 85-115 or 85-117 % in case of log-transformation). At all three dose regimens, BK0023 was also bioequivalent to the reference product in terms of pharmacokinetic profile of serum filgrastim. The frequency of the treatment-emergent adverse events did not differ significantly between treatments, with the most frequent untoward effects being back and bone pain. CONCLUSIONS: Equivalence could be established using both the baseline-adjusted values and the original unadjusted values. The tested formulation at all three dose regimens was also bioequivalent to the reference product in terms of pharmacokinetic profile.

Hematology and serum chemistry parameters in juvenile cynomolgus monkeys (Macaca fascicularis) of Mauritius origin: comparison between purpose-bred and captured animals.

BACKGROUND: The vast majority of non-human primates used for experimental activities are purpose-bred. However, in case of particular procedures or specific projects, it may still be necessary to use animals captured in the wild. METHODS: Sixty cynomolgus monkeys were randomly selected on the basis of breeding origin, and assigned to two groups, each of fifteen males and fifteen females. Analyses included the most frequently investigated parameters for hematology, coagulation, and biochemistry. RESULTS: Differences were observed in some parameters, particularly in eosinophils, basophils and monocytes, and in fibrinogen, total protein, globulins, alanine amino-transferase, creatinine, aspartate amino-transferase, alkaline phosphatase, gamma-glutamyl transferase, lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase, iron, potassium, and phosphorus. CONCLUSIONS: Some values in the cynomolgus monkey may show significant differences according to the breeding background of the animals. Only data obtained from animals of similar origin have to be compared, to avoid misinterpretation during the evaluation of the experimental results.