What is Clinical Research and How Does it Work?

Why is clinical research important?

Clinical research involves an organized series of tests that study how well new drugs, a medical device, or medical intervention work in the human body. These clinical studies are a key part of the drug development process. They are important to help researchers understand specifics about how new drugs can affect people’s health. Without clinical research, new medications can’t be developed in ways that are safe and accurate. 

How does clinical research work?

The drug development process and clinical research have progressed significantly since medications were first discovered. For your safety and well-being, researchers aren’t just able to do whatever they want within the clinical study. The entire process follows a system of guidelines and regulations. Clinical studies follow a process where medications are first studied in smaller groups of people, and as results become available, the tests eventually involve more people. These studies are done in stages or phases. Each phase has a specific target focus–drug safety, how well the drug works (efficacy), dose, or side effects of taking the medication.²

Here’s a closer look at what happens during each clinical study phase:

Pre-clinical phase:

This phase takes place before the “clinical phase begins” and does not involve humans. In this phase, drugs are studied in animals to determine whether or not the drug would be safe for use in humans. Researchers also examine how the drug potentially works, is processed within the body and how it interacts with other drugs.²

The results of the pre-clinical phase must be reported to the United States Food and Drug Administration (FDA) and approved, before the tested medication can be studied in humans. 

After the FDA approves the Investigational New Drug (IND) application, the next phase of the clinical study can begin. 

Phase I:

This is the first phase of clinical development in which the drug is tested in humans. This phase looks at the maximum dose of the drug that can be used safely, how the drug is processed by the body, and how the drug may interact with other drugs in a small group of people (about 20-80 people). People that participate in Phase I clinical studies may be healthy volunteers or have the disease of interest for the study.^2-4

Phase II:

This phase specifically includes people that have the disease of interest. Healthy volunteers are not able to participate in this phase. There is a small number of people who participate in these studies, but the group is larger than Phase I (about 100-300 people). This phase looks at how safe the drugs, ideal doses of the drug, and ways to give the drug.^2,3 

Phase III: 

This phase of study typically takes place in a much larger group of people (about 300-3000). The purpose of this phase is to understand how well the drug works in a larger group of people with the disease of interest. The criteria to participate in a study in this phase is usually very specific and typically match closely with the lab results and symptoms experienced by people who have the disease. It also looks to make sure that the drug is safe to be used in a larger group of people. This phase also closely looks at the most common side effects associated with the drug.^2,3

Based on the results of the Phase III clinical study, the FDA, often with input from other external committees, may decide to approve or deny the New Drug Application, (NDA). If approved, the potential medication can be put on the market for the specific disease or indication that was studied. There is a very large amount of research information that must be submitted to the FDA for the review as part of the application.

Phase IV:

This phase takes place after the potential medication is FDA approved and available on the market. The purpose of this phase is to look at less common side effects associated with the drug, how much it should cost, and how well the drug works in populations of people much different than those in earlier phases of the clinical study.²

Interested in learning more?

Find out why clinical research is so important for Black people in particular and how they are designed to protect us.