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What is a clinical trial?


Updated February 02, 2009

Definition: A clinical trial is a type of research carefully designed to determine the effectiveness and safety of a drug or device in humans. The first step is phase I, which seeks to determine the safety of a drug in a small number of healthy volunteers. The goal of the subsequent phase II trial is to determine the safety, side effects and dosage of the drug in people suffering from the targeted disease. The final phase III trial carefully examines the drug's effects on survival, prevention of disease recurrence, or other such "end points" in a large sample of patients. FDA approval of a new drug usually requires one or more successful phase III trials. The process is highly regulated and expensive: each drug candidate costs an average of $500 million and can take a decade or more to evaluate. Participation in clinical trials is essential for developing new treatments for metastatic melanoma and other forms of skin cancer.
Also Known As: clinical study, trial
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