A Braun1, J Alsenz. 1. Preclinical Research Department, F. Hoffmann-La Roche Ltd., Basel, Switzerland.
Abstract
PURPOSE: Protein aggregates are thought to be involved in the immunogenicity of recombinant proteins in humans. To probe human IFN-alpha formulations for the presence of soluble protein aggregates, enzyme-linked immunosorbent assays (ELISA) were developed. METHODS: For the detection of IFN-alpha-IFN-alpha and HSA-IFN-alpha aggregates, sandwich ELISAs were developed using a monoclonal anti-IFN-alpha antibody as a capture antibody and the same anti-IFN-alpha antibody and an anti-human serum albumin (HSA) antibody (HRP-labeled), respectively. RESULTS: Marketed freeze-dried, HSA-containing IFN-alpha-formulations tested in the ELISAs all contained IFN-alpha-IFN-alpha and/or HSA-IFN-alpha protein aggregates, although in varying amounts. These aggregates were predominantly IFN-alpha dimers and 1:1 conjugates of HSA with IFN-alpha. Test formulations revealed that aggregation of IFN-alpha was strongly affected by the presence of pharmaceutical excipients, pH of the formulation, lyophilisation procedure, and storage temperature and time. CONCLUSIONS: The ELISAs are rapid, highly specific for aggregates in the presence of both IFN-alpha and HSA monomers and allow the direct detection of both types of aggregates in formulations in the nanogram range. The new assays will assist the monitoring of the aggregate-inducing processes during IFN-alpha formulation and storage in an early phase and the development of aggregate-free IFN-alpha formulations.
PURPOSE: Protein aggregates are thought to be involved in the immunogenicity of recombinant proteins in humans. To probe humanIFN-alpha formulations for the presence of soluble protein aggregates, enzyme-linked immunosorbent assays (ELISA) were developed. METHODS: For the detection of IFN-alpha-IFN-alpha and HSA-IFN-alpha aggregates, sandwich ELISAs were developed using a monoclonal anti-IFN-alpha antibody as a capture antibody and the same anti-IFN-alpha antibody and an anti-humanserum albumin (HSA) antibody (HRP-labeled), respectively. RESULTS: Marketed freeze-dried, HSA-containing IFN-alpha-formulations tested in the ELISAs all contained IFN-alpha-IFN-alpha and/or HSA-IFN-alpha protein aggregates, although in varying amounts. These aggregates were predominantly IFN-alpha dimers and 1:1 conjugates of HSA with IFN-alpha. Test formulations revealed that aggregation of IFN-alpha was strongly affected by the presence of pharmaceutical excipients, pH of the formulation, lyophilisation procedure, and storage temperature and time. CONCLUSIONS: The ELISAs are rapid, highly specific for aggregates in the presence of both IFN-alpha and HSA monomers and allow the direct detection of both types of aggregates in formulations in the nanogram range. The new assays will assist the monitoring of the aggregate-inducing processes during IFN-alpha formulation and storage in an early phase and the development of aggregate-free IFN-alpha formulations.
Authors: T Staehelin; B Durrer; J Schmidt; B Takacs; J Stocker; V Miggiano; C Stähli; M Rubinstein; W P Levy; R Hershberg; S Pestka Journal: Proc Natl Acad Sci U S A Date: 1981-03 Impact factor: 11.205