From The MS Information Sourcebook, produced by the National MS Society.
Clinical trials are studies to see if a promising new drug or other medical therapy can actually help people. Such studies are essential before any new or experimental drug or therapy for a particular disease can be evaluated by the U.S. Food and Drug Administration for safety and effectiveness. The studies must be carefully designed and controlled to make sure that the results are valid and not due to factors other than the effects of the drug or therapy being tested.
Studies Evaluating MS Must Account for Variations
This is especially critical in evaluating treatments for MS because the course of MS naturally varies according to the type of MS and the individual.
A high percentage of people with MS can have spontaneous improvement of symptoms, regardless of type of treatment, or even without treatment, particularly in the early years of the disease. In addition, some studies have indicated that the "placebo response" may account for up 70% of the improvements that occur among patients. The "placebo response" is a reported or actual improvement of symptoms in people who have received an inactive or sham therapy instead of the actual medication under study. This response, which tends to be short-lived, apparently results from the expectation or anticipation of benefit from the treatment. These factors tend to complicate studies on the effect of therapies and must be taken into account when the trials are designed.
Trials Should Be Carefully Controlled and 'Double-Blind'
Well-designed clinical trials should be controlled—with about half the participants receiving the treatment being tested and the other half receiving a placebo or previously-approved treatment—and "double blind," meaning that neither the researchers nor the participants are aware of who is receiving which treatment until the conclusion of the study.
Clinical Trials Often Involve Repeated Tests over Time
Often, in order to determine whether an experimental therapy is working and is safe, participants are required to undergo any number of tests during the course of the study. They might include, but are not limited to, repeated MRI scans, blood tests, clinical measures of gait and disability, and even tests of cognitive functioning. The types of testing required are fully described in the consent agreement.
Ordinarily, Patients Aren't Asked to Pay to Participate
In most cases, the costs of a legitimate clinical trial are covered by the agency or company sponsoring the study. Individuals considering participating in a clinical trial should be sure to determine whether they will be responsible for any costs.
When rigorously followed, these rules help ensure that the results of the clinical trial are truly due to the therapy under study, and not a result of spontaneous improvement, the placebo effect, or bias by a researcher wanting the treatment to succeed. It is the responsibility of conscientious professionals to conduct proper clinical trials before making claims about a new treatment.
Kalb R. (ed.) Multiple Sclerosis: The Questions You Have; The Answers You Need (3rd ed.). New York: Demos Medical Publishing, 2004.
—Ch. 3 Treatments