A Triple-Transgenic Immunotolerant Mouse Model

Abstract

Avoiding unwanted immunogenicity is of key importance in the development of therapeutic drug proteins. Animal models are of less predictive value because most of the drug proteins are recognized as foreign proteins. However, different methods have been developed to obtain immunotolerant animal models. So far, the immunotolerant animal models have been developed to assess one protein at a time and are not suitable for the assessment of combination products. Our aim was to develop an animal model for evaluating the impact of manufacturing and formulation changes on immunogenicity, suitable for both single protein and combination products. We constructed two lines of transgenic mice expressing the three human coagulation factors, II, VII, and X, by inserting a single vector containing the three coagulation factors encoding sequences separated by insulator sequences derived from the chicken beta-globin locus into the mouse genome. Immunization of transgenic mice from the two lines and their wild-type littermates showed that transgenic mice from both lines were immunotolerant to the expressed human coagulation factors. We conclude that transgenic mice immunotolerant to multiple proteins can be obtained, and that these mice are potentially useful as animal models in the assessment of immunogenicity in response to manufacturing changes. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 102:1116–1124, 2013

Effects of recombinant human prothrombin on thrombin generation in plasma from patients with hemophilia A and B

“…It is well known that the hemostatic effect of FVIII and FIX without inhibitors does not increase linearly with the FVIII/FIX levels, as patients with mild hemophilia (> 5–40% FVIII/FIX) seldom have bleeding if not exposed to trauma or surgery. The FEIBA preparation used in the current study was measured to contain 0.12 mg FII per U using a prothrombinase assay . Thus, the FII added to the hemophilia plasmas with FEIBA 0–1 U mL −1 is 0–120 mg L −1 (i.e.…”

Recombinant human prothrombin (MEDI8111) prevents bleeding in haemophilia A and B mice

“…Human FII (hFII) plasma concentration was quantified essentially as described by Brenden et al . with an LLOQ of 1 mg L −1 .…”

“…Human FVIII and FIX plasma concentrations were determined with the chromogenic assays Chromogenix Coatest SP4 FVIII from Diapharma, West Chester, USA (lower limit of quantification (LLOQ) 10 mIU mL À1 ) and Rox FIX, Rossix AB, M€ olndal Sweden (LLOQ 5 mIU mL À1 ), respectively. Human FII (hFII) plasma concentration was quantified essentially as described by Brenden et al [12] with an LLOQ of 1 mg L À1 .…”