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Clinical Trials
What is a Clinical Trial?
A clinical trial is a research study designed to answer specific questions about new therapies or new ways of using existing treatments. Clinical trials determine whether new drugs or treatments are both safe and effective. Carefully conducted clinical trials are the safest way to find treatments that work in people. Trials are conducted in four phases, I through IV. Phases I through III expands the study population to progressively larger groups prior to review by the Food and Drug Administration (FDA). Phase IV studies takes place after the drug or treatment has been licensed and marketed.

Phase III clinical studies are sometimes called pivotal trials because their results determine whether a drug gets approved by the FDA or not, and how the drug will specifically be used. In Phase III cancer studies, the investigational treatment is often added to the standard of care and compared against a placebo arm.  

What do clinical trials accomplish?
Most clinical trials are done to see if a new drug or device is safe and effective in people. Clinical trials are also done for other reasons. Some compare existing treatments to determine which is better. The current, approved treatments are called the "standard treatments." Sometimes clinical trials study different ways to use standard treatments to make them more effective, easier to use, and/or reduce side effects. Studies of cancer treatments are also sometimes done to learn how to best use the treatment in a different population, such as children or elderly patients, in whom the treatment was not previously tested.

Why are they important?
Clinical trials contribute to the overall knowledge and progress in cancer treatment. All of today’s standard treatments for cancer began in clinical trials. Many cancer clinical trials are run by cooperative groups comprised of many different treatment centers across the country. Cooperative group studies have helped establish the effectiveness of lumpectomy for breast cancer, new chemotherapy drugs for colon cancer, and the combination of chemotherapy and radiation for advanced cervical cancer.

Clinical trials are also important because they create a controlled environment in which to test a new therapy, and are specifically designed to ensure that any benefits from the investigational drug are real and not due to chance. For each clinical trial, researchers develop strict eligibility criteria, such as age, sex, type and stage of disease, previous treatment history, and other medical conditions. They also carefully control the dose and schedule of the investigational drug, called the trial protocol. These criteria help to reduce the possibility that results might be compromised by variations among patients or treatment centers.

What are the benefits to patients who participate in a clinical trial?
It is important to test drugs and medical products in the people they are meant to help. It is also important to conduct research in a variety of people because individuals may respond differently to treatments. The FDA seeks to ensure that people of different ages, races, ethnic groups, and genders are represented in clinical trials.

For cancer treatment, clinical trials often offer the best hope for patients with advanced disease to obtain and benefit from investigational therapies. Because new cancer drugs are usually tested in the sickest patients first, they can offer hope for patients who have exhausted all other approved treatment options. Drugs that inhibit tumor blood vessel growth, called angiogenesis inhibitors, are examples of therapies that have benefited cancer patients enrolled in clinical studies of these agents. Many people treated for cancer are now living longer thanks to participation in clinical trials.

Not everyone who applies for a clinical trial will be accepted. Volunteers may be excluded based on the eligibility criteria and/or the number of participants needed by the researchers to collect enough information to determine the safety and effectiveness of a therapeutic agent. Patients who are interested in participating in a clinical study should ask their treating physician about whether they might be eligible. The National Institutes of Health also keeps a comprehensive database of all clinical studies being conducted for specific medical conditions. This information can be accessed at