Phases of Clinical Trials

If you’re considering joining a clinical trial, you may want to learn about the different phases of clinical trials. Depending on your interests and treatment goals, you may want to join a clinical trial that’s in a particular phase. 

There are four phases of clinical trials for testing cancer drugs and treatments:

Phase I

  • tests a new drug for the first time in humans
  • shows how much of the new drug is safe and how often doctors should give it
  • shows what side effects patients can expect
  • includes a small number of patients

Phase II

  • builds on data collected in Phase I
  • tests how well a drug works on a specific kind and stage of cancer
  • includes a small number of patients

Phase III

  • tests drugs that researchers think will be effective based on results of Phase II
  • compares new and standard treatments
  • usually, researchers must randomly assign patients to get the new or standard treatment
  • can include hundreds or thousands of patients

Phase IV

  • evaluates the long-term safety and effectiveness of the treatment
  • these studies usually take place after the treatment has been approved for standard use
  • several hundred to several thousand people may participate 

Other Types of Clinical Trials

In addition to the four phases for standard cancer trials, there are other types of clinical trials:

  • Quality-of-life (also called supportive care) trials explore ways to improve comfort and quality of life for cancer patients and survivors. These trials may study ways to help people who are experiencing symptoms like nausea, sleep disorders, or other effects from cancer and treatment.
  • Genetic studies are sometimes part of another cancer clinical trial. The genetic part of a trial may focus on how genetics can affect how a patient responds to cancer treatment, or if genetics play a role in making a patient more likely to get cancer or have certain side effects.

Provider Clinical Trial Search

Helping Doctors Find Clinical Trials for Their Patients

Are you a doctor looking for a clinical trial to enroll your patient in?

This mobile-friendly search tool is specially designed to be used on your smartphone or tablet device. You can save this link to your smartphone screen and use it like an app: http://oncore-app1.hci.utah.edu/sip-mobile/flowchart.html. As a physician, you can use this tool to find clinical trials that may be appropriate for your patients, including trials available at HCI's community clinics. clinical trials mobile search