- What is a clinical trial?
- Where do the ideas for clinical trials come from?
- Who sponsors clinical trials?
- What are the different types of clinical trials?
- What are the phases of clinical trials?
- What is a clinical trial protocol?
- What is a placebo?
- What is a control group?
A clinical trial is a research study designed to help determine if a new treatment is safe and effective. This new treatment might be a new medicine or new biomedical device, or a new type of procedure for treating an illness. Clinical trials are a key step in the process of obtaining approval to make new treatments available to the public.
Ideas for clinical trials come from researchers working in a variety of settings. These researchers may be at hospitals or medical centers, universities, or may work for pharmaceutical or medical device companies. Initial research into a new drug or device or therapy is done in the laboratory and in animal studies. If the results of these initial studies are promising, a clinical trial is designed to further examine the safety and efficacy of that treatment or procedure.
Clinical trials are sponsored and funded by a wide variety of organizations. Trials may be funded by the National Institutes of Health (NIH) or other federal agencies such as the Department of Veterans Affairs (VA) or the Department of Defense (DOD). Many trials are funded by private companies such as pharmaceutical companies or medical device companies. Trials may also be funded by physicians, medical institutions, or foundations.
Clinical trials fall into one of four main categories:
- Treatment trials are designed to test new treatments, testing new drugs, new medical devices, or new medical procedures.
- Prevention trials examine better or new ways to prevent disease from occurring or to prevent disease from returning. The methods being tested in the trial may involve drugs, lifestyle changes, dietary modifications, or vaccines.
- Screening trials examine methods of detecting disease or health problems.
- Quality of Life trials are designed to find ways to improve the quality of life and comfort level of those with chronic illnesses.
After being studied in a laboratory and animal studies, most new treatments are examined in a series of clinical trials which follow a progression of steps or phases toward approval by the FDA (Food and Drug Administration). Trials conducted at each phase have a different purpose and are designed to answer different questions.
Phase I Trials involve the testing of a new drug or treatment in a fairly small group of people (20-80) in order to evaluate its safety, to determine a safe dose range, and to identify side effects. This type of trial may involve patients who have the illness or may involve healthy volunteers.
Phase II Trials involve testing the new drug or treatment in people with an illness or condition and usually involves a somewhat larger group of people than a phase I trial. This type of trial seeks to provide preliminary information about the safety and benefits of the new drug or treatment.
Phase III Trials are designed to confirm the safety and effectiveness of the new drug or treatment and usually involve comparing that new treatment with one that is already approved for use by physicians and patients. Phase III trials are usually designed to randomly assign patients to one of three treatment groups who receive:
- The new medication or treatment, or
- The standard treatment, or
- An inactive medication or treatment called a placebo.
This type of trial may be designed such that neither the study physician nor the patient knows which group the patient was assigned to. This helps to insure that the data is collected and analyzed in a fair manner.
Phase IV Trials are also known as post market studies and are performed after FDA approval. They seek to obtain additional information about a treatment or device's safety, efficacy, and optimal use.
Every clinical trial has a carefully designed plan that provides complete details on the conduct of the trial. The protocol is written by the physician or sponsor of the trial and is provided to all the physicians helping to carry out the trial. The protocol provides details on the:
- justification for conducting the study
- types of people and the number of people needed to answer the question being studied
- schedule of tests and procedures involved in the study
- medications and/or medical devices involved
- length of the study
- plan for analyzing the data produced
- guidelines and rules for stopping the study
- guidelines for ending the study
The purpose of the clinical trial protocol is ensure that the study is justified, that the protocol is safe for the participants of the study, and that the study is designed to allow the research questions to be answered.
A placebo is an inactive substance, either a pill, liquid, or powder that has no bodily effect or treatment value. Often times, a clinical trial is designed to compare the new medication to a placebo in order to determine the effectiveness of the new medication. A study may be designed such that the participants assigned to the control group of a study receive a placebo.
The control group of a clinical trial serves as a "baseline" against which the results of the experimental group can then be compared. Often times the clinical trial is designed such that the control group receives the standard treatment or a placebo, while the treatment group receives the new medicine or experimental treatment.