What are clinical trial “phases?
There are four types of clinical trials: • In Phase I clinical trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects. • In Phase II clinical trials, the study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety. • In Phase III studies, the study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely. • Phase IV studies are done after the drug or treatment has been marketed. These studies continue testing the study drug or treatment to collect information about their effect in various populations and any side effects associated with long-term use.
Clinical trials of experimental drugs proceed through four phases: • In Phase I clinical trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects. • In Phase II clinical trials, the study drug or treatment is given to a larger group of people (100-300) to see if it is effective and to further evaluate its safety. • In Phase III clinical trials, the study drug or treatment is given to large groups of people (1,000-3,000) to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely. • Phase IV clinical trials are done after the drug or treatment has been marketed. These studies continue testing the study drug or treatment to collect information about their effect in various populations and any side effects associated with long-term use.
Clinical trials are conducted in a series of steps, called phases – each phase is designed to answer a separate research question. • Phase I: Researchers test a new drug or treatment in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects. • Phase II: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety. • Phase III: The drug or treatment is given to large groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely. • Phase IV: Studies are done after the drug or treatment has been marketed to gather information on the drug’s effect in various populations and any side effects associated with long-term use. Additional Resource Information on clinical trials can be found at http://clinicaltrials.
Clinical trials that test drugs go through four stages or “phases.” A Phase I clinical trial is the first time an experimental drug is tested in humans. It is usually given to a small group of healthy participants. The purpose of a Phase I study is to gather information on the drug’s safety. A Phase II clinical trial is usually the second stage of testing a new drug in humans. This phase commonly involves 100 to 300 participants. The participants usually have the disease for which the experimental drug is being tested. The purpose of this phase is to gather additional information on safety and to see how effective the drug is. A Phase III clinical trial commonly involves 1,000 to 3,000 participants that have the disease for which the experimental drug is being tested. This phase usually compares the experimental drug to the current approved treatment for the disease. Side effects and effectiveness are also monitored during a Phase III trial. A Phase IV clinical trial is done after the
There are four phases associated with a clinical trial. • Phase I involves testing in 20 – 80 people to evaluate the drug’s safety and determine a safe dosage range and identify side effects. • In Phase II, the drug or treatment is tested on 200-300 people to see if it is effective and to further evaluate its safety. • In Phase III, the study drug or treatment is given to a larger group, 1000 – 3000 people, to confirm its effectiveness, monitor side effects and collect information that will allow the treatment to be used safely. • Phase IV studies are done after the drug or treatment has been approved by the Food and Drug Administration (FDA) and made available for public use. Studies continue to test the new drug or treatment to collect information on their effect in various populations and any side effects associated with long-term use.
