What are the steps of a clinical research study?
Most clinical research that involves the testing of an investigational drug progresses in an orderly series of steps called phases. This allows researchers to ask and answer questions in a way that gathers reliable information about the study drug and also protects participants. Clinical studies are usually classified into 1 of 4 phases: • Phase I Studies: These first studies in people evaluate how a new investigational drug should be given (by mouth, injected into the blood, or injected into the muscle), how often, and what dose is safe. A Phase I study usually enrols only a small number of participants, sometimes as few as a dozen. • Phase II Studies: A phase II study continues to test the safety of the investigational drug and begins to evaluate how well the drug works often compared to placebo (an inactive substance).
