New medical treatments and pharmaceuticals are constantly entering the market, and most are developed using clinical trials. These are scientific studies using human volunteers, usually to test a product or treatment. They can help determine whether a specific therapy is safe and effective for treating a specific condition. Clinical trials are vital tools in finding new, effective medical treatments.
Clinical trials are the backbone of many new therapies, particularly cancer treatments, and most are conducted at universities or research hospitals. Most have specific inclusion/exclusion criteria that varies from trial to trial. For instance, one on an obesity drug might specify participants who have not had weight-loss surgery or those who have not taken prescription weight-loss medication in a particular period of time. This ensures that unknown or unusual circumstances are less likely to affect the trial's outcome.
Some trials use a control group that is given a placebo medication or the standard treatment for a disease, and the results are compared against those who receive the experimental treatment. Others use a double blind process, in which neither the researchers nor the patients know which group is receiving the treatment or a placebo.
A patient volunteer may experience unpleasant side effects and may have to visit a medical professional often for evaluation. These factors can be a disadvantage, but many volunteers are willing to risk these side effects for the chance of a cure. Participants may leave the trial at any time, although they may be asked why they are dropping out of the study.
Clinical trials are usually conducted in three phases before the drug tested receives government approval. Phase I is the first and smallest study, using groups numbering between 20 and 80 patients to test the effectiveness and optimal dosage of a drug and to identify any side effects. Phase II uses groups of between 100 and 300 people to further test the safety of the drug and to make more notes on its effectiveness. Phase III compares the experimental treatment to standard therapies and evaluates it further for safety and dosage ranges. When a drug receives approval, it goes through a Phase IV trial that helps determine its risks and benefits.