Phase 3 Clinical Trials

If a drug shows enough promise in phase 1 and phase 2 then it moves to the next stage - phase 3 clinical trials. During phase 3 clinical trials the drug in question is compared to already existing standard treatment(s) for the disease/condition. The goal is to determine if the new treatment is better than, the same as or less effective than the standard treatment(s). Randomization of the trial volunteers also takes place during this phase, this means that will be randomly assigned to receive either the standard treatment or the new/experimental treatment being studied.

More information about the safety and side effect profile of the new drug is gleaned during this phase and the sample size of participants that are studied is much larger than the first two phases because this makes it easier to get a better estimate of what could potentially happen if the new drug was available to everyone who has the condition. Phase III clinical trials also typically include people of various ages, both genders, and multiple ethnicities. The point of doing this is so that the results will more accurately mimic the vast population of potential users of the drug.

At the end of phase III clinical trials, the researchers will often seek peer reviews from other medical experts by publishing their results in peer-reviewed medical journals. The reason for doing this is to get the profession opinions and input from others in order to make sure that the results they got from the studies are sound, accurate and make good clinical sense. Upon completion of phase III clinical trials, a drug company can then go ahead and request approval from the FDA to market the drug. Other key areas of research during this phase include:

• Dosage intervals: this means basically how much of the drug should be given and how often
• Interactions: both drug-drug and drug-disease i.e. interactions of the drug with other drugs and with other diseases
• Pharmacodynamics: i.e. studying what the drug does to the body
• Pharmacokinetics: i.e. studying what the body does to a drug (how the body absorbs it, breaks it down, distributes it and then gets rid of it)
• Risk-benefit information: this means comparing what the possible risks (including side effects) of using the medication are in contrast to what the possible benefits of it are

Phase 3 Clinical Trials Snapshot

• Goal: How does it compare to standard treatment(s) for the disease?
• Number of Participants: hundreds to thousands
• Duration: one(1) to four(4) years
• Outlook: about 25-30% of drugs advance successfully from phase III clinical trials to receive approval to be marketed

It should be the function of medicine to help people
die young as late in life as possible.
-Ernst Wynder

Return from Phase 3 Clinical Trials to Clinical Trial Process

Return to Home Page

May 25, 2009

This site complies with the HONcode standard for trustworthy health information:verify here.