Modulation of Interferon-Specific Gene Expression by Albumin-Interferon-α in Interferon-α-Experienced Patients with Chronic Hepatitis C

Abstract

Albumin-interferon-α (alb-IFN) is a novel recombinant protein derived from IFN-α2b genetically fused to human albumin. The resulting single polypeptide combines in one molecule the antiviral properties of IFN-α with the long serum half-life of albumin. IFN-mediated biological responses stem from the engagement of IFN-α with its target receptor and subsequent modulation of IFN-specific gene (ISG) expression. To evaluate the pharmacodynamics of alb-IFN during the Phase I/II study conducted in patients with chronic hepatitis C (CHC) who had previously failed IFN-α-containing regimens, ISG induction was evaluated in peripheral blood and compared with antiviral response. Whole blood was obtained at day 0, day 7 and day 28 from 21 patients enrolled in the higher dose (500–900 μg) alb-IFN cohort, who received two injections on day 0 and day 14. Taqman real-time PCR was used to assess candidate ISG expression. There was sustained induction on day 7 and day 28 of the ISG's OAS1, IRF-7, IFI44 and IFI27. Although all patients showed a molecular response to alb-IFN, individual variability in pretreatment gene expression levels and fold of modulation during treatment was observed. At day 28, induction of OAS1, IFI44 and IRF7 showed pairwise correlation in individual patients ( P<0.05). Moreover, the induction of expression at day 28, and pretreatment levels of OAS1 and IFI44 correlated with hepatitis C virus RNA reduction at day 28 ( P<0.05). In conclusion, alb-IFN demonstrated robust induction of ISG that was consistent with the response associated with an IFN-α.