Infusion reactions (IRs) are complex, immune-mediated side effects, also known as hypersensitivity reactions (HSRs) that can occur upon intravenous infusion of pharmaceuticals, leading to severe and sometimes life-threatening conditions in patients. Those reactions may arise from a real allergy which is immune globulin class E (IgE) mediated, or a “pseudoallergy”. The latter involves no IgEs and may arise because of activation of the complement (C) system called C activation-related pseudoallergy (CARPA). Products triggering severe adverse events can include both traditional small molecules but also biologics such as therapeutic antibodies (ABs), fusion proteins, etc. and novel formulations using liposomes or nanotechnology. Regulatory guidance on the assessment of C-mediated infusion hypersensitivity has been published recently for the case of generic liposome production. Hemocompatibility (blood safety) testing for medical devices is requested by EMA and FDA since many years. However, regarding the potential of new pharmaceuticals causing allergies and/or CARPA remains a significant challenge for the industry during nonclinical development as no established safety biomarker nor meaningful, validated animal models are available up to date. During the project “IMMUNOASSAYS” Dr Fülöp proposed the development and quantitative evaluation of three promising specific safety biomarkers via ELISA technology.
The aim of “IMMUNOASSAYS” was to develop assays for key biomarkers of the complement system for in vivo testing to identify potential side effects in animals prior to administration of the nanomedicines and therapeutic antibodies to humans. Since the porcine CARPA studies are the best currently available in vivo experiments to study the capability of the previously mentioned nanomedicines and biologics, pig specific complement protein ELISAs were started to be developed under the project. The key biomarkers C3a, Bb and the membrane attack complex (sC5B9 or TTC) are excellent complement proteins to be analyzed via novel assays, however, the use of the human assays for animal C determination is not possible due to the high specificity of the antibodies to human C proteins and the species specificity of the respective amino acid sequence. So far, validated complement assay systems for nonclinical studies in laboratory animals are very limited, so “IMMUNOASSAYS” had the aim to close this gap with porcine specific complement protein ELISA development.
During the two years of the IMMUNOASSAYS project period, the porcine C3a specific assay was fully developed, validated and already available for research studies. Furthermore, the porcine TCC assay has progressed significantly, yet the development is not fully finished yet during the project period time. The development of porcine Bb specific ELISA development started as well, but will be finished after the ending of IMMUNOASSAYS.
