Type of Trials

In Phase I clinical trials researchers are often testing a treatment which may be in the earliest stages of its development in a small group of healthy people (ie. usually 10 to 30 participants). The information gathered from such trials will provide the manufacturers with important data on how the medicine is tolerated and metabolized in healthy people and whether any side effects have been experienced by those taking part in the trial. These trials are an important step in finding new treatments for the future and it is for these studies that PAREXEL is looking for healthy participants.

Once a new medicine has successfully passed the Phase I study stage, the drug will be administered to a larger number of people (i.e. usually 100 to 200 patients). In these trials the drug will be tested in those who are actually suffering from the condition the medicine is intended to treat. The objective of Phase II studies is to help the manufacturer identify those medicines with genuine therapeutic potential - a drug that has successfully passed the Phase II stage has a 60% chance of actually being approved to go on to the market.