title: Development and characterization of a non-cell-based assay to assess the presence of neutralizing antibodies to interferon-beta in clinical samples.
abstract: Assessment of immunogenicity is an integral part of product development and involves evaluation of binding and neutralizing antibodies. The use of cell-based assays for detection of neutralizing antibodies (NAbs) is usually a regulatory expectation. Different cell-based assay formats are available for detection of anti-interferon-beta (IFN-β) NAbs but all present technical difficulties and limitations. In this paper, a non-cell-based NAb assay which overcomes the limitations of cell-based assays is described. This NAb assay utilizes an electrochemiluminescence detection platform and is based on the first step involved in all IFN-β-induced biological activities, namely the binding of IFN-β to its receptor, which is inhibited when NAbs are present. Using this approach, NAb titers in clinical samples from multiple sclerosis patients treated with IFN-β were determined and compared with those obtained using existing cell-based NAb assays. The sensitivity of the assays was not comparable, the cell-based approach having superior sensitivity. However a good correlation between the two approaches was observed. This study illustrates the practicality and feasibility of non-cell-based neutralization assays in the context of immunogenicity, however the utility of this approach would need to be assessed on a case-by-case basis for each therapeutic.
authors.affiliation: Cytokines and Growth Factors Section, Biotherapeutics Group, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Hertfordshire, EN6 3QG, UK. Isabelle.Cludts@nibsc.org
authors.forename: Isabelle
authors.initials: I
authors.lastname: Cludts
authors.forename: Anthony
authors.initials: A
authors.lastname: Meager
authors.forename: Robin
authors.initials: R
authors.lastname: Thorpe
authors.forename: Meenu
authors.initials: M
authors.lastname: Wadhwa
mesh_terms: D057134:Antibodies, Neutralizing / Q000097:blood*; D015331:Cohort Studies; D057809:HEK293 Cells; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D000068556:Interferon beta-1a; D016899:Interferon-beta / Q000037:antagonists & inhibitors / Q000276:immunology* / Q000627:therapeutic use; D008163:Luminescent Measurements / Q000379:methods*; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000276:immunology / Q000628:therapy; D009500:Neutralization Tests / Q000379:methods; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000627:therapeutic use
chemical_list: D057134:Antibodies, Neutralizing; D011994:Recombinant Proteins; D016899:Interferon-beta; D000068556:Interferon beta-1a
keywords: AVA; ECL; Electrochemiluminescence; IFN-β; Immunogenicity; Interferon beta; MxA; NAbs; Neutralizing antibodies; Non-cell-based assays; RGA; RRMS; antiviral assay; electrochemiluminescence; interferon-beta; myxovirus resistance protein a; neutralizing antibodies; relapsing-remitting multiple sclerosis; reporter gene assay