Recombinant human proteins, reproductive

Fusion proteins that consist of recombinant forms of human proteins fused to the Fc portion of human IgG tend to be less species specific than monoclonal antibodies. Etanercept and abatacept showed cross-reactivity to rodents and rabbits, and therefore a full reproductive and developmental toxicity package could be obtained in rodents and rabbits for these agents. For alefa-cept species cross-reactivity was limited to the macaque. 

The analysis of effects on reproductive performance (including fertility) and development by human recombinant proteins is a complex issue. In general, non-human primates are often the most relevant species. The studies have generally been complicated by abortions however, there has been no evidence of a teratogenic effect (Trown et al, 1986 Terrel and Green, 1993). Particular consideration should be given to development of mechanistic-based studies to avoid the need for non-human primate studies for the next generation of IFN therapies. 

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