People volunteer to participate in a clinical trial. They may be people who have, or are at risk for having, the disease the drug or treatment is designed for. The drug or treatment may also be tested in healthy volunteers. Volunteers must meet the criteria for participation, which are different for each clinical trial.
Clinical Trial Sponsors
The funding for conducting a clinical trial comes from its sponsor(s). These may be organizations, individuals, physicians, foundations, medical institutions, biotechnology or pharmaceutical companies, or federal agencies such as the National Institutes of Health (NIH), the Department of Defense, or Department of Veterans Affairs. The NIH created a Rare Diseases Clinical Research Network to conduct clinical studies of rare diseases in adults and children.Types of Clinical Trials
Clinical trials try to find better ways to prevent, diagnose, and treat diseases. The types of clinical trials are:- Treatment trials – This type of trial tests new drugs, treatments, or new approaches to surgery or radiation therapy.
- Prevention trials – Research in this type of trial is looking for better ways to prevent a disease from occurring, or keep a disease from coming back. This may involve lifestyle changes (such as quitting smoking or increasing exercise) and/or taking medicines.
- Diagnostic trials – This type of trial looks for better ways of diagnosing a particular disease or condition.
- Screening trials – Research in this type of trial is trying to find the best way to detect certain diseases or health conditions in people.
- Quality of life trials – Also called supportive care trials, this type of research is trying to improve the comfort and quality of life for people with long-term illness.
Treatment Trial Phases
Clinical trials of drugs or treatments are in four phases:- Phase I tests a new drug or treatment in a small group of people (20 to 80) for the first time. Phase I tests for the best dosage of a new drug and what side effects it might have.
- Phase II tests this new drug or treatment in a larger group of people (100 to 300). Phase II evaluates the effectiveness of the drug or treatment in treating the medical condition it is designed to treat.
- Phase III expands the testing to an even larger group of people (1,000 to 3,000). Phase III may also compare the new drug to the standard therapy or placebo.
- Phase IV takes place after the drug or treatment has been licensed and marketed.
Clinical Research Protocol
Each clinical trial is conducted according to a specific plan called its protocol. The protocol is designed to answer research questions and safeguard the participants’ health. The research protocol is approved and monitored by an independent committee called an institutional review board (IRB). The IRB is made up of physicians, statisticians, and members of the community. They make sure that the clinical trial is ethical and protects the rights of the participants.As the clinical trial progresses, the team of researchers reports the results at scientific meetings, in medical journals, and to the sponsor(s). This makes the results, whether encouraging or not, public and allows others in the medical community to comment on the research.
Sources:
"Are Clinical Studies for You?" Participate in Clinical Studies. NIH Clinical Center. 3 Aug 2009
"How Does Clinical Research Work?" NIH & Clinical Research. U.S. National Institutes of Health. 3 Aug 2009
"Understanding Clinical Trials." ClinicalTrials.gov. 20 Sep 2007. 7 Aug 2009
