| clinical trial | (n) a rigorously controlled test of a new drug or a new invasive medical device on human subjects; in the United States it is conducted under the direction of the FDA before being made available for general clinical use, Syn. clinical test |
| phase i clinical trial | (n) a clinical trial on a few persons to determine the safety of a new drug or invasive medical device; for drugs, dosage or toxicity limits should be obtained, Syn. phase I |
| phase ii clinical trial | (n) a clinical trial on more persons than in phase I; intended to evaluate the efficacy of a treatment for the condition it is intended to treat; possible side effects are monitored, Syn. phase II |
| phase iii clinical trial | (n) a large clinical trial of a treatment or drug that in phase I and phase II has been shown to be efficacious with tolerable side effects; after successful conclusion of these clinical trials it will receive formal approval from the FDA, Syn. phase III |
| phase iv clinical trial | (n) sometimes the FDA approves a drug for general use but requires the manufacturer to continue to monitor its effects; during this phase the drug may be tried on slightly different patient populations than those studied in earlier trials, Syn. phase IV |
| preclinical trial | (n) a laboratory test of a new drug or a new invasive medical device on animal subjects; conducted to gather evidence justifying a clinical trial, Syn. preclinical phase, preclinical test |
