What are clinical trials?
Clinical trials are conducted to test out the safety and efficacy of new medications or medical devices. Drug and device testing begins with laboratory research that is conducted over years consisting of experiments in animals and human cells. If the initial laboratory research is a success, the data is sent to the Food and Drug Administration (FDA) to move forward with research in humans.
Human Clinical Trial Phases
Phase I studies assess the safety of new medications or devices. Studies at this phase are designed to examine the how the medication is absorbed, metabolized, and excreted. This phase also investigates the side effects that occur when the drug is administered at various doses.
Phase II studies test the efficacy of the new drug or device. Majority of phase II studies are randomized meaning one group of patients receive the study medication and the second "control" group receives a standard medication or placebo. Most phase II studies are "double blinded" meaning neither the patients or the research staff know who received the experimental medication.
Phase III studies involve randomized and blind testing on a much larger scale. These studies provide the FDA with a better understanding of the effectiveness of the drug or device, the benefits and the range of possible adverse reactions. Once a phase III trial is complete, the pharmaceutical company can request FDA approval for marketing of the medication.
Phase IV studies are conducted after a drug or device has been aproved for consumer sales. The main objectives for this phase are to compare a drug with current drugs already on the market, monitor a drug's long-term effectiveness and impact on the patient, and determine the cost-effectiveness of a drug relative to other options on the market.