Nonclinical studies, neutralizing antibody

Primates may be needed when it becomes clearer that the parameters of interest (hematology, blood chemistry, histopathology, etc.) can only be studied in species that are phylogenetically closer to H. sapiens. This is often the case when candidate drugs are proteins (e.g. animal-derived monoclonal antibodies), and antibody formation may be major issue and may dictate the choice of species. For example, it may be known that only the chimpanzee does not develop neutralizing antibodies to the drug, which would lead one to select that species as the nonclinical model. 

Various types of antibody responses can develop in animals in nonclinical toxicology studies that can potentially alter interpretation of the study (i) antibodies that are clearing or sustaining (ii) antibodies that neutralize the pharmacological activity of the biological and (iii) antibodies that neutralize natural, endogenous counterparts (Dempster, 2000 Wierda et al., 2001 Koren et al.,2002). 

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