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Clinical Trials

  • Research that studies or tests a treatment on people
  • For people who have the condition being studied or healthy volunteers
  • Drugs and treatments go through four phases of testing before they can receive FDA approval
  • Involves medical oncology, internal medicine, pediatrics

Clinical Trials


It seems like every time you turn on the TV, there is an advertisement for a new medication, procedure, or treatment. But the process of drug approval (and availability) is a long and complicated one. Right now, researchers are studying thousands of new drugs and treatments for cancer and other conditions, such as diabetes, lupus, and asthma. These new treatment approaches are tested, both in and out of the laboratory, to see if and how they work in a select group of people. These closely monitored tests are called clinical trials.

Every new medication, procedure, and treatment that doctors use in the general population must first undergo a series of clinical trials before receiving the required Food and Drug Administration (FDA) approval.

“Clinical trials help us find out if a promising new treatment is safe and effective for patients,” says Pat LoRusso, DO, who is the director of Yale Cancer Center at Smilow Cancer Hospital’s Early Phase Clinical Trials Program.  

People who volunteer for clinical trials benefit from cutting-edge treatments not available elsewhere. They also become part of an effort to advance medicine, helping future patients to receive newer, better treatments, she says.

What is a clinical trial?

When a scientist makes a medical discovery in the laboratory (called bench research), it needs to be tested on people outside the lab setting. These tests are known as clinical trials. Clinical trials are required to test medications, devices, and procedures on people. Through these trials, researchers can learn if the treatment is safe, document its side effects, and discover how effective the treatment is for the patients who volunteer to try them.

If you or a loved one has cancer, for example, clinical trials are worth discussing with your medical oncologist. For people who do not have success with conventional therapies, drug treatments being tested in clinical trials can offer hope.

What are the four clinical trial phases?

Drugs and treatments go through several steps or phases of testing before they can receive FDA approval, which is needed before a drug can be legally released to the market and prescribed to patients. If a drug, device, or treatment is successful in one phase, it will move to the next one. Here are the four major clinical trials phases:

  • Phase I trials: During this first phase, physician-scientists test the possible side effects of an experimental treatment on a select—yet small—group of consented patients. Often in this phase, they are assessing how the patient’s body metabolizes or handles the drug. Researchers closely monitor patients to find a safe dose, decide on the best delivery method (orally, intravenously, or by infusion), and record any side effects patients experience. This phase usually lasts less than 18 months.  
  • Phase II trials: Next, the drug or treatment is tried on a larger group of patients (around 100 patients). The purpose of Phase II trials is to determine the effect the treatment has on a disease, like cancer, and to see how the treatment impacts the rest of the body. This information is precisely logged by researchers at medical centers. This phase can last up to two years.
  • Phase III trials: In this phase, the experimental drug or treatment is tried by large groups (up to several thousand) of patients. The purpose is to discover how effective the new drug or treatment is compared to standard treatments already available to the public for the disease type. Once Phase III is complete, a new drug application needs to be filed with the FDA. The FDA then reviews all the research on the drug or treatment. If approved by the FDA, the drug manufacturer can release the product for use in patients by doctors everywhere.
  • Phase IV trials: After the product reaches the public, this testing phase provides extra information about long-term risks and benefits and how the drug or treatment should be optimally used. 

Where are clinical trials available?

Academic medicine institutions like Yale Medicine regularly perform clinical trials. Open trials, a term that means the researchers are seeking new patients, are listed with the institution online. A nationwide listing of current clinical trials can be found through the U. S. National Library of Medicine’s website. Cancer clinical trials supported by the National Cancer Institute (NCI) can be found on the NCI website

Who can volunteer for a clinical trial?

Anyone can volunteer for a clinical trial; however, with each study, researchers are often looking for a specific type of patient. They typically are looking for people with a like-stage of disease, and list specific inclusion and exclusion criteria as to which patients will or will not be eligible. So, not everyone with a specific disease will be eligible for every study, even if they are interested in participating. Additionally, many trials have a limited number of patients and also may require starting at a particular time, especially in early-stage trials.

Doctors often need both healthy and unwell people in order to fully test a new treatment. They need people of all races, ethnicities, and gender. There may be age restrictions, depending on whom the treatment is designed for (pediatric or adult patients, for example). 

How do you join a clinical trial?

Sometimes, if you are being treated at an academic medical center, your doctor will recommend a clinical trial for which you may be eligible. Or, you can search for trials that are currently seeking participants. 

Another way is to create a volunteer profile, if you’re a current Yale Medicine or Yale New Haven Health System patient, using your MyChart account. Click the “research” button at the top of your MyChart page. This allows you to express interest in study categories, which helps our recruitment team match you to trials for which you may be eligible. While your profile indicates that you are interested in volunteering for a study, you are not committing yourself to participate.

What is unique about Yale Medicine’s involvement in clinical trials?

Yale Medicine and Yale Cancer Center have numerous clinical trials available for patients who are seeking the most advanced treatments available. With the development of the Phase I Program at Yale Cancer Center, for example, there are nearly 40 Phase I trials open and that number is growing.

“Numerous studies that have shown that, often, the best medical care given to a cancer patient is on a clinical trial,” says Dr. LoRusso. “If you seek out a trial, even if you are eligible, you do not have to participate if you are uncomfortable. There have been many advances in cancer treatment in the last several years—and all have resulted in patients making a commitment to participate in a clinical trial.”