A Comprehensive Look at Clinical Trials

Types of Clinical Trials

When a drug company develops a new medication, the process starts in test tube and animal studies. These studies give researchers an idea of how well a medication works and what kind of side effects it might have in humans. If the results of early studies look good, the drug company designs and pays for clinical trials to test the medication in humans. These trials are divided into three stages, which are known as Phase I, Phase II, and Phase III trials. Let's take a look at how they break down:

Sometimes, Phase II and III trials are combined into a Phase II/III trial. This speeds up the process of gathering information. When all three phases are complete, the information from the trials is submitted to the FDA. The FDA reviews the information, and then approves or rejects the new medication. Sometimes the FDA asks for more information or further trials before making the decision.

A drug company may run an expanded access program before the medication is approved by the FDA. In expanded access, individuals who won't benefit from medications already approved by the FDA may receive the medication. The company collects safety information from all expanded access participants.

If a medication is approved, the pharmaceutical company may conduct Phase IV trials. Phase IV trials are used to gather long-term safety information. These trials involve thousands of people, and can give information about very rare side effects. In addition to drug companies, the federal government and local agencies also sponsor trials. Some examples are the ACTG (AIDS Clinical Trials Group) and the CPCRA (Community Programs for Clinical Research on AIDS). These trials answer important questions about HIV treatment and care, such as how soon after infection to start HIV treatment.