November 13, 2003 at 10:45 PM CST - Updated June 25 at 1:10 AM
Clinical Trials Clinical trials are research studies designed to improve knowledge about the cause, treatment and prevention of medical conditions. A trial may be sponsored through one or more sources, such as a federal agency (like the National Institutes of Health), pharmaceutical company, health organization, foundation or medical institution. The research generally takes place in a doctor’s office, clinic, hospital or university.
There are several different types of trials. Screening trials are designed to study tests or procedures that improve the ability to detect disease before signs and symptoms become apparent. Diagnostic trials examine tests and procedures in an effort to find more accurate methods of diagnosis for a particular medical problem. Prevention trials study ways to reduce the risk of developing a disease, or in some cases, prevent a disease from recurring. Quality of life trials explore interventions to provide comfort or improve the quality of life for patients with chronic disease (such as cancer). Treatment trials are designed to find more effective treatment to cure or slow the progression of disease (such as new drugs or new method of surgery). Sometimes doctors will study new combinations of treatment or a new use for an old drug.
The Process Testing of new treatments takes place in several stages. Initially, researchers may examine ideas and concepts in the laboratory. Therapies that show promise are then tested in animals. Animal studies help doctors study how the therapy works and learn about any potential side effects or toxicity. However, results in animals don’t always correlate to humans.
Human trials must be approved by the Food and Drug Administration. In addition, an Institutional Review Board (IRB) of participating hospitals reviews research studies to make sure the trials are safe and fair for participants.
Once human studies are approved, research enters Phase I trials. This is a small-scale study to determine the safety of a treatment and the best dose and method of administration. Doctors will also observe participants for treatment side effects. Phase I trials typically involve only a small number of people (sometimes as few as 10 or 20 participants).
If a drug passes Phase I, researchers can apply for FDA approval to begin Phase II studies. Phase II studies examine the effectiveness of a treatment while continuing to monitor for safety and side effects. Phase II studies generally involve about 100 to 300 participants.
Many treatments never make it past Phase I or Phase II studies. Sometimes doctors find out the therapy doesn’t work as anticipated or has some undesirable side effects. If, however, Phase II trials show promise, approval may be given to begin Phase III testing. In Phase III trials, doctors compare the new therapy with current, standard treatments. Patients are usually randomly assigned to receive the new therapy or the standard treatment. In many cases neither the researchers nor the participants know who gets which treatment (a double-blind study). Phase III studies are conducted with a large number of patients (often 1,000 or more) and may be performed at several sites throughout the country. With the large numbers of participants, doctors gain a better understanding of how well a drug works in a diverse population group. Researchers also continue to monitor patients for development of potential side effects from the therapy.
Once Phase III studies are complete, researchers must analyze the data and submit the results to the FDA for approval. The FDA may approve the drug, ask for clarification or results, require further testing or turn down the application. Even if a drug is approved, manufacturers must continue to monitor the safety and risks of a therapy. These post-marketing studies (sometimes referred to as Phase IV studies) are important because, even with extensive testing, sometimes side effects or dangers only become apparent after a drug has been used for some time. At any time, a drug or treatment can be withdrawn from the market if safety or efficacy becomes a concern.
Taking Part in a Clinical Trial Clinical trials are important because, without them, there would be few advances in medicine. Patients with medical conditions who participate in clinical trials have the chance to obtain cutting-edge treatments that could eventually become standard therapy in the future. In addition, participants receive high quality monitoring of their condition.
Despite the benefits, participants need to understand there are some risks to participation in a clinical trial. New therapies aren’t necessarily better than standard treatments and don’t always produce intended results. In some cases, treatment can turn out to have unpleasant or toxic side effects. Sometimes a treatment works for some patients and not for others.
If you are considering taking part in a clinical trial, check out the clinical trial website to locate potential studies. Look for trials that are still “open” (i.e., still enrolling patients). Closed trials are still ongoing but are no longer accepting new participants. Also determine how far you are willing to travel, since potential trial sites may not be located close by. Clinical trials usually have very specific guidelines for participation. Your family health care provider can help you sort through the information and narrow your search to an appropriate study. Once you make the call, you will be screened by a clinician to determine if you meet the criteria for participation.
If you are accepted into a clinical trial, you will be asked to sign a lengthy consent form. The form should explain the purpose of the study and outline the steps in the study protocol. You should also understand the expectations of participants, known and potential side effects of the treatment, tests involved, amount of monitoring, expected length of participation and provisions for follow-up care once participation has ended. Find out what extra costs you may incur. In many cases, health insurance does not reimburse for clinical trial participation. Sometimes patients receive treatments for free, but must absorb the cost of travel, overnight stays and lost time from work. In some cases, patients may be reimbursed for expenses. If you have any concerns, don’t be afraid to speak with researchers or the trial coordinator. Keep in mind that although researchers prefer to see patients finish a trial, participants are free to leave a clinical trial at any time.