The developmental toxicity testing of biologics.

The characteristics of biologic drugs, as compared with small molecules, confer significant advantages for both the drug developer and the prospective patients. The necessity for, and the timing of, developmental toxicity testing in the preclinical program must be considered. Choice of an appropriate test system is of particular importance, one that shows pharmacodynamic activity comparable to man. Where the conventional rodent/non-rodent species show such functional cross-reactivity, those species can be used in developmental testing, but often the only relevant species will be a nonhuman primate, in which case an extended study design (the ePPND) should be the default. Such an approach provides appropriate toxicity screening while reducing animal usage.