title: Assessment of the immunogenicity of mechanically induced interferon aggregates in a transgenic mouse model.
abstract: Pump delivery of human interferon alpha-2B (IFNα2b) has the potential for inducing immunogenic drug aggregates. We therefore evaluated the immunogenicity of mechanically induced IFNα2b aggregates to assess this risk. Transgenic human-IFNα2b (TG) and wild-type (WT) FVB/N mice (n = 8 and n = 9/group, respectively) were administered mechanically agitated drug [45 Hz for 6 h (LLA) or 24 h (HLA)], chemically modified drug [low pH (pH 4.0) or metal oxidized (OXD)] or unstressed drug (native). Mice received IFNα2b (50 μg; 100 μg/mL; s.c.) formulations on days 0, 7, 14, and 21. Drug-binding and neutralizing antibody titers were determined after 28 d. Aggregate concentrations were highest in OXD and HLA formulations but OXD had more dimers/trimers. Geometric mean titers were 1:131, 1:728, 1:1573, 1:871, and 1:10,240 for WT mice (n = 9) and 1:207, 1:587, 1:1810, 1:571, and 1:2,153 for TG mice (n = 8) for native, LLA, HLA, pH4, and OXD groups, respectively. Mechanical agitation of IFNα2b induced equivalent titers of immunoglobulin to that of metal oxidation, both capable of binding to or neutralizing the drug in WT and TG mice. Thus, by limiting metal contamination and by inclusion of a stabilizing agent to mitigate drug aggregation, the risk of anti-drug immunoglobulin may be reduced in a pump delivery scenario.
authors.affiliation: Chris Barnard Division of Cardiothoracic Surgery, Groote Schuur Hospital/University of Cape Town and Medical Research Council Western Cape Heart Research Grouping, Cape Town, South Africa.
authors.forename: Paul
authors.initials: P
authors.lastname: Human
authors.forename: Helen
authors.initials: H
authors.lastname: Ilsley
authors.forename: Cynthia
authors.initials: C
authors.lastname: Roberson
authors.forename: Eric
authors.initials: E
authors.lastname: Grovender
authors.forename: Bill
authors.initials: B
authors.lastname: Van Antwerp
authors.forename: Eric
authors.initials: E
authors.lastname: Fogt
authors.forename: Peter
authors.initials: P
authors.lastname: Zilla
mesh_terms: D000818:Animals; D005260:Female; D006801:Humans; D055261:Immunogenetic Phenomena / Q000187:drug effects* / Q000502:physiology; D007369:Interferon Inducers / Q000008:administration & dosage* / Q000097:blood; D016898:Interferon-alpha / Q000008:administration & dosage* / Q000097:blood; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D013314:Stress, Mechanical
chemical_list: D007369:Interferon Inducers; D016898:Interferon-alpha
keywords: HPLC (high performance/pressure liquid chromatography); capillary electrophoresis; drug delivery systems; immunology; mechanical activation; protein aggregation; protein delivery; stability; transgenics