Clinical trials (also known as clinical investigation or medical research) 1 are an important part of the process in which new drugs, treatment plans, or other such interventions are tested and validated under very strict medical supervision. Clinical trials are also known as investigational trials or as clinical research.
The purpose of a clinical trial is to evaluate whether some new drug or procedure is effective in preventing or treating a specific disease. As an example, suppose drug A shows promise as an effective treatment for high blood pressure but a diet rich in vitamin Z has also demonstrated the same effect. A clinical trial could be conducted to evaluate which of the two is the better treatment choice.
Clinical trials are comprised of various stages ranging from Stage 1 to Stage 4. The stages are described, in general terms, as follows. 2
Phase I: A new drug or treatment will be tested in a small group of people for the first time to evaluate its safety, determine a safe dosage range, and identify side effects.
Phase II: The drug or treatment is given to a larger group of people to see if it is effective and to further evaluate its safety.
Phase III: The drug or treatment is given to larger groups of people to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
Phase IV: Studies are done after the drug or treatment has been proven to be effective in order to gather information on the drug’s effect in various populations and any side effects associated with long-term use.
Any clinical trial, regardless of stage, will begin by defining both the inclusion and exclusion criteria of the study. These criteria will determine who will be eligible to participate (inclusion) in the study and who will not be eligible (exclusion). By way of example, suppose that a drug company wants to evaluate the effectiveness of a new treatment for lung cancer but does not wish to deprive anyone of a treatment (such as surgery, chemotherapy, or radiation) that has been shown to be effective in the past. The inclusion criteria might include patients that have not benefited from other forms of treatment, whose cancer has spread to other organs, and are not expected to survive beyond a few months. Obviously, anyone not meeting these criteria will be excluded from the study.
After a patient has met the requirements for inclusion in the clinical trial, the process cannot proceed until an informed consent has been obtained. Informed consent can be defined as furnishing each potential participant in the study with all the relevant information (such as potential complications, possible benefits, side effects from the investigational drug, and the probability of unforeseen complications) necessary for the potential study participant to make a decision as to whether or not to begin participation in the study. Only after these steps have been resolved will the participant enter (be enrolled in) the study.
Once the participant has entered the study he or she will be closely monitored for any unforeseen complications as well as those that can be reasonably expected to occur and were included in the informed consent process. It is important to remember that the participant always has the option to leave the study at any time. All investigational studies will also include an exit point (the point at which the investigational treatment has been completed and all the anticipated data has been obtained).
For More Information
Medical specialists such as neurologists and oncologists (doctors who specialize in the treatment of cancer) will be aware of various clinical trials related to their specialties and will share that information with their patients, if appropriate.
Clinical Trials.Gov: (US) This web site was created by both the National Institutes of Health and the National Library of Medicine and contains a more detailed discussion of clinical trials. It is easy to use, understand, and has numerous links to other related web sites.
The National Cancer Institute at the National Institutes of Health: (US) This site is devoted to the latest information on the prevention, diagnosis, and treatment of cancer. It contains a major database concerning both ongoing and proposed clinical trials at different locations across the nation.
Notes
1. “Clinical,” in the context of this posting, refers to medicine as it is practiced “at the bedside” or in an office / clinic.
2. Definitions adapted from those given by the National Institutes of Health and the National Library of Medicine.
