Behind the scenes of a clinical trial

July 21, 2016 | by City of Hope

Behind the scenes of a clinical trail Download the Behind the Scenes of a Clinical Trial infographic by clicking on the image.



Most people know that the U.S. Food and Drug Administration must approve a drug before it reaches the market or a hospital room. But very few people outside of the medical field know what happens before the drug gets to the FDA.

Clinical trials (or clinical studies) are medical studies that focus on establishing the safety and effectiveness of new, potentially beneficial drugs by testing them on increasingly large groups of human subjects. These trials can involve new medications, treatments, devices and even psychological therapies. It’s a years-long process that involves constant study and research before the new drug is ever presented to the FDA.

At City of Hope, at least 400 clinical trials are going on at any given time. To help illuminate the clinical trial process for patients, here are five facts you may not have known.

1. Clinical trials require approval before commencing.

Clinical trials are only approved once an institutional review board, or independent ethics committee, has weighed the potential benefits against the possible risks and determined the testing worthy. An institutional review board or independent ethics committee pores over all materials related to the study before and during the trials.

Often years of preclinical work has gone into researching and experimenting on isolated living cells, while zeroing in on potential benefits, appropriate dosage ranges, problems and side effects, and the most effective ways of applying the drug, before human subjects can become involved.

2. There are different types of trial subjects.

Often, existing patients with a specific condition or particular set of characteristics, such as age, gender, or stage of disease, will volunteer to participate in a clinical trial. In other instances, trials will make use of volunteers who are otherwise healthy, depending on the type of drug or device being tested.

Patients already under medical care may choose to participate because the trial gives them access to new treatments not available to others. Many volunteers sign on because they want to help advance science and medicine toward new cures. All participants must go through a process of informed consent with the trial’s principal investigators before it starts.

3. Clinical trials are run by special investigators.

Medical professionals who are trained in the “Good Clinical Practice” guidelines designed to safeguard subjects and assure proper collection of data can become investigators on clinical trials. By participating, investigators can position themselves to discover new developments and stay on the front edge of emerging medical discoveries, especially in their fields of expertise.

They can have an impact on advancements, while authoring papers and articles that push their field forward. Investigators are often paid for their work, unlike the subjects of clinical trials.

4. There are four distinct phases of a clinical trial.

Phase 1 focuses on safety by keeping the sample group small, from 20 to 80 people. It’s an initial evaluation of how the human body handles a new drug, while investigators take note of safe dosage ranges and any side effects.

In phase 2, the experiment group grows to 100 to 300 subjects, with more of a focus on effectiveness, though safety is always being evaluated.

During phase 3, investigators increase the sample size to 300 to 3,000 subjects and lengthen the amount of time the drug is taken, while the same safety and efficacy parameters are studied.

Phase 4 requires an even larger sampling group, with a focus on long-term effectiveness and safety, as well as how the new drug compares with other similar drugs and their costs, before approval is sought from the FDA.

5. Only a small percentage of new drugs ever hit the market.

The review process takes anywhere from six to 12 months, depending on whether the new drug is only a minor improvement on an existing therapy, a major advancement or a completely new treatment. Right now, the National Institutes of Health service lists more than 215,000 clinical studies currently in progress around the world.

Ultimately, the FDA only approves about 10 percent of the drugs that went through clinical trials in the U.S.


If you are looking for a second opinion or consultation about your treatment, request an appointment online or contact us at 800-826-HOPE. Please visit Making Your First Appointment for more information.


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