The decision to enroll in a clinical trial should involve a discussion between the person with prostate cancer and that individual’s physician. Your participation should depend on many factors, including your motivation for enrolling in a trial, the stage of your prostate cancer, and the trials available and its phase.

When you decide to enroll in a clinical trial it is important to fully understand the trial, your possible benefits as well as any possible risks you might experience. As a first step in making a decision to participate in a trial you need to have a comprehensive conversation with your individual doctor as well as the clinical trial doctor (or nurse).

Among the many factors to consider in deciding on a trial should include your prostate cancer stage, your prior treatment history, the level of support you might receive from your caregivers, and the financial policies of your medical insurance company.

You should understand the many different types of prostate cancer clinical trials there are, so you can see if the trial fits your goals in participating. Researchers have different goals in mind when they design trials and you should understand these goals. These include:

Interventional Trials*- Testing a therapy, such as a drug or other medical intervention, for treating existing prostate cancer.

Prevention Trials- Finding ways to stop the development of prostate cancer, including changes in lifestyle, diet, or medications.

Diagnostic and Screening Trials- Evaluating ways to better diagnose prostate cancer.

Non-Interventional Trials- Studying prostate cancer in a large group of people to better understand it as a health issue.

Supportive Care or Quality of Life Trials- Examining ways to improve the comfort and quality of life for people with prostate cancer.


  • Interventional trials are structured differently from the other trial categories. In the United States, as required by the Food and Drug Administration (FDA), they usually include three separate trial phases.  When the trial is taking place outside of the US, those phases are also required by the equivalent governing bodies of the country where the trial is being conducted.

Interventional trials in prostate cancer are currently the most common type of clinical trial going being run.

These interventional trials involve examining new drugs that have shown promise in animals and, increasingly more      common, drug combinations.

These trials include biological therapies that interrupt the molecular processes, which cancer cells require to grow; Immune therapies involving the boosting of the body’s own immune system so that it can better fight cancer; Tumor-directed treatments that target the cancer cells themselves; Stem cell therapy which include both allogeneic transplantation (from another person) or autologous transplantation (from one’s own blood-forming stem cells).

Interventional trials in prostate cancer, actually in all cancers, also have different phases depending upon the questions being asked.

Phase 1 trials are the first type of study done in humans. It follows successful animal trials. Its purpose is to determine safety and to evaluate side effects of the investigational treatment. Phase 1 studies also test how the drug is absorbed, distributed, and eliminated from the body. Often people who do not have the disease (healthy individuals) participate in Phase 1 trials. The number of people involved at this stage is usually very small.

Phase 2 trials are sometimes divided into Phase 2A and Phase 2B, however sometimes these two sub-phases are combined into one trial. Phase 2 trials assess dosing. It is designed to determine the best drug dose to use and how much of a drug is safe. Phase 2 trials are also used in small numbers of prostate cancer patients. Phase 2 trials can also measure treatment efficacy.

Phase 3 trials are the most commonly media reported trials. They are designed to be very large multicenter trials usually comparing the intervention against the standard of care treatment. Successful results are required for a drug or other treatment to receive approval for commercial use.  Phase 3 trials are designed to test efficacy and safety, as well as to monitor for side effects.

Pase 4 Trials – Sometimes, based on the recommendation of the FDA researchers also conduct an additional Phase 4 trials after a drug has been approved. These trials are designed to collect additional information about the drug or treatment.