Experimental Treatment
Introduction
Patients and their family members often ask if an experimental treatment is available for a condition or disease. This is especially true when a condition is life threatening or will have a dramatic effect on quality of life, such as impending blindness, deafness, senility, or immobility. In these requests, there is often a note of desperation.
Medical researchers are constantly engaged in a search for better treatments of human diseases and disorders. Experimental treatments may be tried when more conservative treatment has failed. Experimental treatment is often innovative and unconventional, and may also carry with it considerable risk. It is, by definition, treatment that has not been proven safe and effective in humans. While it is an essential part of science and medicine, experimental treatments are not intended for every patient.
Experimental treatments receive a great deal of attention in the popular media. Research papers presented at scientific meetings often receive prominent media attention. Scientific meetings are frequently the source of dramatic stories about potential new cures, discoveries, and breakthroughs. Often this attention brings a treatment to the public's attention before the validity and importance of the work, as well as the potential for harm has been established. Findings presented at these meetings have undergone only minimal peer review.(1) Therefore, treatments that have received media attention often fail to meet the initial expectations.
Clinical Trials and Experimental Treatment
Experiments on humans (clinical trials) are conducted to determine the safety and effectiveness of new drugs, devices, procedures, and various doses or combinations of drugs. These clinical trials are conducted after pre-clinical trials (animal studies) are completed.
Clinical trials represent a special area of research. They are notable because of the involvement of human subjects who are often particularly vulnerable because they suffer from serious illness, may be searching desperately for treatments, and are being asked to participate in research that carries unknown risks and questionable benefits.
Clinical trials are limited in size and not every willing patient is admitted into clinical trials.
Clinical trials are divided into phases:
- Phase I: Treatment is offered to patients who have not responded to conventional therapy. There is risk to these patients because the toxicity to new treatments is not known -- although the effects on animals have been evaluated before clinical trials are started. Phase I clinical trials generally only involve 10 to 15 patients. They are necessary to determine the appropriate drug dose and schedule and to look for side effects. Side effects and safety data continues to be collected throughout all phases.
- Phase II: Twenty to 40 patients with a very strictly defined set of symptoms and characteristics are selected for this phase. The goal of this phase is to determine the responsiveness of the disease to the drug. The strict control of patient characteristics often excludes patients from the trial. This set of patient characteristics are known as exclusion criteria, inclusion criteria, or admission eligibility and rigidly define the characteristics of patients who are eligible for admission into a study. These criteria are necessary in order to eliminate or account for the effect of extraneous factors on the results. (see page on the scientific method)
- Phase III: Researchers compare the new treatment to standard regimens. Two groups of patients are gathered, one receives the new treatment, and the other does not. Patients are "randomized" to one group or another (i.e. every patient has an equal chance of ending up in the new treatment group, they are assigned to a group by random selection, like the flip of a coin). Patients are, again, selected using a very rigid set of criteria.
- Phase IV: Treatments are adjusted or fine-tuned once they are known to be effective.
References
- Schwartz LM, Woloshin S, Baczek L. "Media coverage of scientific meetings. Too much, too soon?" JAMA 287(21):2859-2963, 2002.
© 2003-2005
The University of Iowa Center for Macular Degeneration
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