Dear Doctors: I have been following your column for a few years now, and clinical trials get mentioned a lot. I know they are used to make sure that a new drug is safe, but other than that, I'm not sure what they are. What exactly is a clinical trial, and how does it work?
Dear Reader: A clinical trial is a scientific study designed to analyze the effects of a medical treatment. That is, not only whether it is effective, but also if it is safe.
You're correct that clinical trials often focus on a newly developed drug. However, the scope of inquiry is actually broader than that. Clinical trials are also used to assess mechanical medical devices, new methods of diagnosing and screening for disease, and novel ways to use and combine existing medications to both treat and prevent disease. They are also used to explore treatments and techniques that can improve the lives of people who are living with a serious or chronic disease.
Like all research, a clinical trial begins with an idea. Successful examples include using an implanted mechanical device to manage heart rate and harnessing the immune system to fight cancer. This is followed by laboratory testing to see if that idea may be viable. If those initial tests show promise, then the researchers devise a detailed plan for a clinical trial. Known as a protocol, it describes every aspect of how the clinical trial will be conducted. It specifies the length of the trial, who is eligible to participate, exact details of the tests and procedures to be used, and any drugs that will be involved, along with their dosage, method and timing of delivery. The information will also include detailed information about any physical effects, good or bad, that a participant may experience.
Clinical trials take place in four separate and distinct phases. They may take place over the course of a few weeks or over several years. The sequence begins with initial tests on a small group of participants. This is to assess safety, and also to identify any side effects that may occur. If phase one is successful, the subsequent segments of the trial include progressively larger groups of participants. By phase four, the drug or device or technique has been approved by the FDA and is being evaluated in a large population.
As we have mentioned here before, the website clinicaltrials.gov offers information about future and ongoing trials. If you are interested in joining a clinical trial, there is information that you should consider. That includes the specific purpose of a study; the reasons why the researchers believe the medication, device or technique will be effective; and, of course, any potential risks to the participants. When someone is selected as a participant in a clinical trial, they are required to sign a detailed consent form that outlines all of this information.
It’s not an exaggeration to say that clinical trials are the backbone of medical advances. Participants often join a trial hoping for help with a problem. But no matter the outcome of a study, they have contributed to medical advancement.
(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)
