Current medical research and opinion

Lipegfilgrastim: pharmacodynamics and pharmacokinetics for body-weight-adjusted and 6 mg fixed doses in two randomized studies in healthy volunteers.

PMID 25251999


Two phase I, single-blind (subject blinded to treatment), randomized studies were conducted to assess the pharmacodynamics, pharmacokinetics, safety, and tolerability of lipegfilgrastim compared with pegfilgrastim in healthy adult volunteers. Study 1 consisted of a pilot safety phase (N = 8) during which subjects received a single body-weight-adjusted subcutaneous dose of lipegfilgrastim 25 µg/kg and a dose escalation phase (N = 45) wherein subjects received lipegfilgrastim 50 or 100 μg/kg or pegfilgrastim 100 μg/kg. Study 2 was a single-blind, fixed-dose study (N = 36) comparing subcutaneous lipegfilgrastim 6 mg and pegfilgrastim 6 mg. Cumulative exposure (AUC0-t last and AUC 0-∞) and peak exposure (Cmax) were higher for lipegfilgrastim than pegfilgrastim after both weight-adjusted and fixed dosing. In both studies, the terminal elimination half-life of lipegfilgrastim was 5-10 hours longer than the terminal elimination half-life for pegfilgrastim at the maximum dose, and the time to maximum serum concentration (tmax) was observed later for lipegfilgrastim than for pegfilgrastim. The area over the baseline effect curve (AOBEC) for absolute neutrophil count (ANC) was approximately 30% greater after lipegfilgrastim dosing compared with the same dose of pegfilgrastim at the maximum dose. Both drugs were well tolerated, with a similar occurrence of adverse events between treatment groups. Key limitations of these studies include the small numbers of subjects and differences in dosage regimens between the two studies. In these studies, lipegfilgrastim provided a longer-lasting increase in ANC compared with pegfilgrastim at an equivalent dose, without increasing the peak ANC values. This may reflect the higher cumulative exposure and slower clearance (therefore longer body residence) of lipegfilgrastim. These data support the use of single-dose lipegfilgrastim 6 mg in subsequent phase III trials as prophylactic treatment for patients receiving myelosuppressive chemotherapy.