Phase III Trials

If a medicine has successfully passed through Phase I and II clinical trials and seems promising, it goes into Phase III clinical trials. By Phase III of clinical trials, medicines are tested in patient volunteers, on a larger scale. This is the last stage of testing before a new medicine is ready to go through the approval process. If a medicine is approved, then it can be released to market.

The Research Nurse explains to Tim that the trial he will be volunteering for is a Phase III clinical trial, so dosage and side effects have been studied already. There may still be some unexpected side effects. Very common side effects are often picked up in Phase I trials, but less common side effects are more likely to appear in Phase III trials, where medicines are tested on much larger groups of people.

Tim is given an informed consent form explaining that the trial is not completely risk free, but that he will be under constant medical supervision and will be given the best possible medical treatment should any side effects occur. He is also free to leave the trial at any time, and on completion, will be given payment as compensation for his time, expenses and medical visits.