A clinical trial is a research study used to test a new medicine, treatment or medical device to see if it is safe and effective before it is approved and released to the public.
To participate in a clinical trial, people must meet certain eligibility criteria to determine that they are suitable to take part.
Participants must be informed of risks and benefits of participating, though some risks may be unknown. They must sign a formal consent form before they can join to be part of the study.
It does not cost the participant any money to be part of a clinical trial, though there may be patient-care expenses that one’s health insurance won’t pay. The trial will last a few weeks to months.
There are several types of clinical trial protocols, depending on what is being tested, but the one for drug approval is outlined below.
Clinical drug trials are divided into four phases after the pre-clinical testing work has been completed.
Phase 1: Testing for safety
This is the first time the new drug or treatment is used on people. The group will have 20 to 80 volunteers and run for a short period of time. This phase tests a drug's safety and helps determine a therapeutic dose.
Phase 2: Determining effectiveness
This trial tests a larger group of participants, between 36 and 300, and lasts longer than the Phase 1 trial study. It also looks for side effects that people may experience with the drug.
Different population groups will be gathered and studied for their responses to the drug. The most effective dose will be determined, as will whether or not it is appropriate to be given along with other drugs.
Phase 3: Final determination of safety and effectiveness
If effectiveness is proven in Phase 2, then this trial tests the new medicine against standard treatments that already exist to treat a particular condition. This group is much larger, with between 300 and 3,000 participants.
These studies are usually performed as controlled studies. All the patients are in a particular stage of their disease. The patients are picked at random for each group.