Pharmaceuticals provide benefits as well as pose risks.
The U.S. Food and Drug Administration (FDA) requires drug companies to conduct Phase III clinical trials to evaluate the efficacy and safety of an investigational drug in the target (intended) patient population. This research provides data on the risks and benefits of the therapy so that the FDA can determine whether to approve a drug for marketing.
Phase III Testing
In order to reach Phase III tesing, an investigational drug requires an established adequate safety profile in a small group of healthy volunteers (Phase I) and some indication of its efficacy in a larger group of patients (Phase II). In Phase III, the experimental drug is given to a large group of people (generally several hundred to several thousand patients in the target population) to confirm its effectiveness, monitor any side effects of therapy, compare it to commonly used treatments, and collect data that will allow clinicians to prescribe the drug safely.
Trial Design
Most Phase III studies use randomized trials with appropriate controls, either an active comparator or placebo (an inactive pill). The trial follows a carefully controlled protocol (study plan) that details how the conduction of the trial, including administered dosages and evaluated endpoints. One of the most important aspects of Phase III or late-stage clinical trials is to evaluate a clinically meaningful endpoint to demonstrate the clinical benefit of an investigational drug. The National Institutes of Health and the FDA strictly monitor these trials.
Gold Standard
The most rigorous Phase III clinical trials are the randomized clinical trials (RCTs) in which patients receive two or more alternative treatments by chance. Neither the study participants or those administering the drug (doctors or nurses) know the type of treatment (double blind). This "blinding" removes any bias from reporting how the drug works in the clinical trial setting. Every clinical trial in the U.S. requires approval and monitoring by an Institutional Review Board to ensure that the conduct of the trial is ethical and that risks to trial participants are minimal. All volunteer patients must sign an informed consent form stating the nature of the study and that they may withdraw at any time if they no longer wish to participate.
Results
The results of Phase III clinical trials are in the new drug application that a company submits to the FDA for drug approval. Drugs companies generally run two or more Phase III trials. These data will appear in the product labeling for the new drug entity.
Tags: clinical trials, investigational drug, Phase clinical, Phase clinical trials, clinical trial, clinical trials evaluate
