Clinical Trials: What You Need to Know

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Phase IV clinical trials: What else do we need to know?

Even after testing a new medicine on thousands of people, the full effects of the treatment may not be known. Some questions often still need to be answered. For example, a drug may get FDA approval based on the fact that it was shown to reduce the risk of cancer recurrence. But does this mean that those who get it are more likely to live longer? Are there rare side effects that haven’t been seen yet, or side effects that only show up after a person has taken the drug for a long time? These types of questions may take many years to answer fully, and may not be critical for getting a medicine to market. They are often addressed in what are known as phase IV clinical trials.

Phase IV studies look at drugs that have already been approved by the FDA. The drugs are already available for doctors to prescribe for patients, but these studies are still needed to answer important questions.

When thinking about taking part in a phase IV trial, you should know that the drug has already been approved for use. You do not need to enroll in the study to get the medicine. At the same time, the care you would get in these types of studies often is very much like what you could expect if you were to get the treatment outside of a clinical trial. You can feel safer because you would be getting a form of treatment that has already been studied a lot. And you would be doing a service to future patients.

Last Medical Review: 09/21/2012
Last Revised: 09/21/2012