Clinical trials are studies managed by government agencies, educational institutions, private not-for-profit organizations, or commercial businesses to develop, produce, and evaluate the effectiveness of new treatments and therapies for diseases.
According to the National Cancer Institute, there are different types of cancer clinical trials, including:
Trials designed to keep cancer from developing in people who have not previously had cancer.
Early Detection Trials
Trials designed to find cancer, especially in its early stages.
Trials designed to test new therapies in people who have cancer.
Quality of Life Studies
Trials designed to improve comfort and quality of life for people who have cancer.
Studies to evaluate ways of modifying cancer-causing behaviors, such as tobacco use.
Most clinical research progresses in an orderly series of steps or phases.
Phase I Trials
The first studies to evaluate how a new drug should be administered (orally, intravenously, by injection), how often, and in what dosage.
Phase II Trials
Studies that provide preliminary information about how well the new drug works, and generate more information about its safety and benefits. A Phase II study usually focuses on a particular type of cancer.
Phase III Trials
Studies that compare a promising new drug, combination of drugs, or procedure with a current standard of treatment.
Phase IV Trials
Studies that include the continuing evaluation that takes place after FDA approval, when the drug is already on the market and available for general use (post-marketing surveillance).
Clinical trial protocols are the action plans or guidelines that must be followed during the course of any study. Guidelines may cover:
- the design of the study -- what it will study and how
- who may participate -- criteria for patients who enter the study
- what medications and medical tests will be used to follow the participants
- what information is being searched for
Several research centers may be involved in the study and each uses the same protocols to ensure that information from all centers can be combined and compared. Included in managing clinical trials are:
- large cancer centers
- university hospitals
- local medical centers
- physician offices
There may be only one or two locations involved in a particular study, or hundreds around the country.
Each protocol in a trial defines specific characteristics, called eligibility criteria, that participants should have in order to participate in the study. Characteristics may include type of disease and its stage, as well as the participant's age and general health. Eligibility criteria help assure that the study results answer the research question and identify who will benefit in the future from the approach being studied.
There are several procedures in place as part of the protocols to protect the safety of the people who participate. Two groups that oversee the safety procedures are the:
- organization that sponsors the study, for example, the National Cancer Institute
- Institutional Review Board (IRB) that oversees clinical research in the healthcare institution.
The IRB includes physicians, other health care providers, consumers, and sometimes members of the clergy, who do not have any personal interest in the results of the study. As neutral reviewers, they ensure that the study is conducted fairly and that participants are not likely to be harmed.
Phase III trials also have a special group called a Data Safety and Monitoring Committee that looks at the test results, monitors the safety of the participants, and decides whether the study should go forward as originally planned.
For information on how to participate in a clinical trial, please talk with your physician.