Pre-Clinical Research
Under FDA requirements, a sponsor must first submit data showing
that the drug is reasonably safe for use in initial, small-scale
clinical studies. Depending on whether the compound has been
studied or marketed previously, the sponsor may have several
options for fulfilling this requirement: (1) compiling existing
nonclinical data from past in vitro laboratory or animal
studies on the compound; (2) compiling data from previous
clinical testing or marketing of the drug in the United States or
another country whose population is relevant to the U.S.
population; or (3) undertaking new preclinical studies designed
to provide the evidence necessary to support the safety of
administering the compound to humans.
During preclinical drug development, a sponsor evaluates the
drug's toxic and pharmacologic effects through in vitro
and in vivo laboratory animal testing. Genotoxicity
screening is performed, as well as investigations on drug
absorption and metabolism, the toxicity of the drug's
metabolites, and the speed with which the drug and its
metabolites are excreted from the body. At the preclinical stage,
the FDA will generally ask, at a minimum, that sponsors: (1)
develop a pharmacological profile of the drug; (2) determine the
acute toxicity of the drug in at least two species of animals,
and (3) conduct short-term toxicity studies ranging from 2 weeks
to 3 months, depending on the proposed duration of use of the
substance in the proposed clinical studies.