What Is a Clinical Trial?

A Phase One Trial is the beginning of the testing process. The drug or device is tested on a small number of healthy volunteers. In CF, sometimes a waiver is given so that the testing is done on people who have CF, but are generally fairly healthy. The results of a Phase One trial show what happens to the drug in a human, and whether side effects occur or change as the amount of the dosage is increased. A Phase One trial usually takes from six to twelve months.

A Phase Two Trial is one done to determine if a drug that was proven safe in Phase One is also effective. In a Phase Two trial, people who have the disease that is being studied are given the drug to test if it has any effect on the disease. This phase is done over several months and another factor is added. The drug is "randomized", meaning that some people get the drug and others get a placebo that looks just like the study drug but has no active ingredients. In this way no one, even the clinicians studying the drug, know if the patients are getting the actual drug and so the results are not biased. A Phase Two trial determines the short-term safety and effectiveness of the drug or device.

A Phase Three Trial is a much larger study done with many more people and for a much longer time. The purpose of a Phase Three trial is to determine further safety, effectiveness, and proper dosages of the drug.

Informed Consent:
Another very important part of clinical trials is that they are performed on people who have agreed to participate. This concept is called "Informed Consent". The voluntary consent of human subjects is absolutely essential. Any clinical investigation involving human subjects is required to obtain an informed consent from the subject prior to the study.
The consent is an actual document designed to give potential subjects all the information they need in order to decide about whether to participate in a trial. It is meant to ensure that they understand all aspects of what is being asked of them, and that there can be discussion between the subject and the investigator. The Informed Consent must be signed before the subject can participate in the clinical trial.