icon-folder.gif   Conference Reports for NATAP  
 
  38th Annual Meeting of the European Association for the Study of the Liver
 
Istanbul, Turkey. March 28-April 1, 2003
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PHARMACOKINETICS OF PEGINTERFERON ALFA-2A (40KD, PEGASYS) COMPARED TO PEGINTERFERON ALFA-2B (12KD, PEGINTRON) IN NAIVE PATIENTS WITH CHRONIC HEPATITIS C (CHC)
 
 
  R. Bruno*, P. Sacchi, V. Ciappina, E. Maffezzini, S.F.A. Patruno, C. Zocchetti, G. Filice, *Presenting Author Infectious And Tropical Diseases, IRCCS San Matteo Hospital - University Of Pavia, Pavia, Italy
 
Background: The currently available pegylated interferon (PEG-IFN) formulations, PEG-IFN ALFA-2A (40KD, PEGASYS) and PEG-IFN ALFA-2B (12KD, PEG-Intron), have different pharmacokinetic profiles. Aim: Objective of this randomized trial is to compare the pharmacokinetics of the two PEG-IFNs in patients with CHC.
 
Patients & Methods: 30 treatment naive patients with CHC and persistently elevated ALT levels have been randomized to receive 180 mcg PEGASYS once-weekly (n=16) or 1.0 mcg/kg once-weekly of PEG-Intron (n=14). Serum concentrations of both PEG-IFNs were measured at baseline and 24, 48, 120 and 168 hours after administration using a quantitative sandwich ELISA (lower limit of detection 125 pg/ml).
 
Results: Serum concentration of PEG-Intron achieved maximum levels at 24 hours after injection and decreased rapidly until 120 hours. Drug was undetectable 120 and 168 hours after injection in 7 (50%) and 11 (78%) subjects, respectively. In contrast, PEGASYS concentrations increased continuously overtime, reaching maximum levels from 48 to 168 hours.
 
Conclusions: Our data demonstrate substantial differences in plasma concentration profiles between PEGASYS and PEG-Intron. Five days after injection concentrations of PEG-Intron are marginal or undetectable, while those of PEGASYS remain stable overtime. These findings suggest that PEG-Intron administration should be intensified to twice weekly to avoid "blips" in viral replication. Differences in pharmacokinetics could explain the differences observed in HCV decay.