Clinical Trials, Medical Teachers
Clinical trials are one of medicine’s best-kept secrets. Such research can provide those suffering from disease, such as cancer or diabetes, with the opportunity for early cure or alleviation of symptoms. Most trials research a specific illness or treatment, such as a drug (as discussed here). But they are also used to evaluate new medical tests and procedures, screening methods or preventive measures.
Patients, however, may be unaware of the hundreds of clinical trials that are currently being conducted throughout the United States. And they may not realize that they may be eligible to participate in such trials.
Finding A Clinical Trial
Some patients may learn about clinical trials from their physician. Other patients, however, may need to do some research to find a clinical trial. Patients interested in clinical trials may learn about existing trials at http://www.centerwatch.com, http://www.clinicaltrials.gov or http://cancertrials.nci.nih.gov. These Web sites list clinical trials by disease topic, as well as provide answers to some commonly asked questions.
In order to participate in a clinical trial, patients usually must meet certain criteria. These criteria may encompass gender, severity of illness, age or certain lifestyle behaviors, such as smoking. Some clinical trials require healthy volunteers. Eligibility is usually determined during a screening process.
All prospective patients receive information about the clinical trial, explaining its process, before they can participate. They must then sign an informed consent form stating that they understand the process and voluntarily agree to take part. Patients are also informed of any follow-up studies and whether they are responsible for any costs associated with treatment, such as diagnostic tests.
Because participation in a clinical trial is voluntary, a patient may choose to leave the study at any time. However, many investigators conducting clinical trials prefer that participants remain in the studies and be available for follow-up. Participants usually need to be geographically close to where the clinical trial is being conducted so that they may be able to come in for follow-up visits to observe their progress.
The Clinical Trial Process
The clinical trial process follows a very regimented format. Whether the trial is evaluating a new drug or a new screening test or some other aspect of medicine, approval must be gained at each step (that is, testing must produce positive results at each step) before the trial can proceed.
For example, the U.S. Food and Drug Administration follows a carefully structured process before approving prescription and over-the-counter drugs. Often, new drugs are first designed using computer models, which provide valuable insight into how a new drug will theoretically work for a specific purpose. The drug is then developed and tested in a small group of animals, such as rats, rabbits or monkeys, to see if it produces the same results reflected by the computer models.
After the safety of a new drug is confirmed through animal testing, the drug is tested in humans. Testing of a new drug in humans is done in four distinct phases:
- •Phase 1 — These studies help define the dose of the new drug and the toxicity (negative effects). Phase 1 studies test the drug for the first time in a small group of volunteers to ensure safety of the drug.
- •Phase 2 — These studies further define the safety and evaluate the effectiveness of the new drug in a larger group of patients with a particular disease or disorder.
- •Phase 3 — These studies are carefully designed to show that the drug works as intended, has a low incidence of toxicity and can be taken safely by patients. The testing is done in a larger group of volunteers and compares the outcomes with those of other treatments being used.
- •Phase 4 — This phase of testing occurs after the drug has already been approved for use and is being prescribed to the general population. These studies continue to monitor the effects of the drug, along with any side effects, that occur with long-term use.
New drugs are frequently tested along with placebos, which look like the drug being tested but contain no active substances. Placebos are used in some of the patients tested to provide a comparison, to verify that the real drug actually has a positive effect on the disorder being treated. This aspect of drug testing is very important. Many conditions, such as depression, pain and even high blood pressure, will respond to placebos, likely because the patient has a strong belief that he or she received the active drug and that the drug is having the expected benefit.
The use of placebos also accounts for any other influence that could interfere with measuring the actual outcome of the drug. For example, a strong public campaign that promotes a healthy diet for lowering cholesterol levels could influence the testing of a cholesterol-lowering drug. The public campaign could lead to lower cholesterol levels in both the patients taking the drug and the patients taking the placebo. Thus, to prove that the drug has an actual benefit, the patients taking it would need to show a greater change in cholesterol levels than would the patients taking the placebo.
Benefits And Risks
There may be notable benefits from participating in a clinical trial. Participants may receive helpful treatment that otherwise would not be available. This may be particularly beneficial to patients with a disease with no known cure. Also, participants may be able to receive closely monitored medical treatment from a well-respected physician or hospital. Some trials provide all treatments, tests and medications at no cost to the patient. And some trials even provide financial compensation for participants in the study.
A committee must approve all clinical research associated with a clinical trial before any patients can take part. This committee, known as an Institutional Review Board (IRB), is mandated by federal regulations and is made up of scientists and members of the general public. The IRB has the responsibility of protecting human participants, making sure that the risks of negative effects are as low as possible and are worth any possible benefit from the treatment. The IRB ensures that the patients’ rights are protected; that the patients are given adequate information about the purpose, procedures, risks and available alternatives; and that the risk of harm is minimized.
However, even though the IRB makes patient safety the top priority, risks may still be present. For example, the treatment may cause side effects. And participants in the control group who receive a placebo may, in fact, be foregoing another type of approved treatment while in the clinical trial. (Sometimes patients are asked to stop other treatments they are already using.)
In addition, once the clinical trial ends, the treatment — regardless of how beneficial it may be — may not be immediately available to participants. The drug may need to go through approval processes for use in the general population, or it may need to undergo additional trials with new participants.
Clinical trials may offer patients an opportunity to experience the benefits of a new development in medical technology or pharmaceuticals. Anyone considering participation in a clinical trial should carefully investigate the study, any possible side effects, and the likelihood that the experience will be beneficial. Eligible patients should carefully read the informed consent form and the description of the trial process, as well as talk to their personal physician, to help make a good choice about participating in a clinical trial.