Source:http://linkedlifedata.com/resource/umls/id/C1882358
NCI: A clinical trial that uses an investigational agent that is available only in very limited quantities and which has never previously given to humans or for which there is extremely limited human experience. Phase 0 clinical trials are intended to enable researchers to understand the path of the drug in the body and its efficacy. Adverse event reporting in Phase 0 trials is expedited.