phase i clinical trial: 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
clinical trial: 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
etanercept: a genetically engineered anti-TNF compound (trade name Enbrel) consisting of receptors that bind TNF; it is injected twice a week in the treatment of rheumatoid arthritis