Introduction

It is essential to learn as much as you can before making a choice for treatment of your prostate cancer. Some men with prostate cancer may be eligible to participate in a clinical trial. This section provides basic information regarding clinical trials so that you can gain an understanding of what a clinical trial is as well as the benefits and risks associated with participation in a trial. You can discuss this information with your physician. In this section you will learn about:

1. What is a clinical trial?
   
2. What are the possible risks and benefits of participating in a clinical trial?
   
3. What are the different phases of a clinical trial and what do they mean?
   
4. What is a placebo?
   
5. What is informed consent?
   
6. What else should I know about clinical trials?
   
   

A clinical trial is a research study, used to answer specific questions about a specific treatment or drug. Clinical trials determine the safety and effectiveness of a drug in treating a particular disease or condition in people. This includes looking at the benefits as well as the potential risks of the drug.

2. What are the possible risks and benefits of participating in a clinical trial?

The possible risks of participating in a clinical trial include:

• You may experience side effects to the drug or procedure
  
  
• You may receive a drug that may be less effective than current therapy
  
  
• You may receive a drug or undergo a procedure which may be ineffective for you
  
  
• You may receive a placebo (does not apply to all clinical trials)
  

The possible benefits of participating in a clinical trial include:

• You may obtain expert medical care by leading physicians in the field of cancer research
  
  
• You may gain access to drugs or treatments not available to other patients
  
  
• You will have your health closely monitored, and you will be evaluated for any side effects you may experience from therapy
  
  
• You may be one of the first to benefit from a drug if the treatment is found to be effective
  
  
• You will be contributing to the advancement of knowledge in the treatment of cancer
  

3. What are the different phases of a clinical trial and what do they mean?

Clinical trials are conducted in humans only after laboratory and animal studies have outlined the potential safety and efficacy of the therapy.

Therapies are tested in a series of clinical trials that progress in "phases." There are four phases of clinical trials. Phases one through three are conducted before a drug is approved by the Food and Drug Administration (FDA). The fourth phase occurs after the therapy has received FDA approval.

Phase I Trials

Phase I trials are the first to be conducted in humans. They are used to determine the safe dosing of the drug being tested.

Phase II Trials

Phase II trials begin to test the effectiveness of the drug in a specific disease (like prostate cancer) while continuing to monitor the drug’s safety.

Phase III Trials

If the drug has been shown to have a beneficial effect in phase II, phase III trials are initiated. Phase III trials help to gain a better understanding of the drug’s efficacy, side effects, and potential risks and benefits. These studies compare the drug either to the existing therapies or a placebo.

It is usually after phase III trials that the FDA determines if the drug should be approved.

Phase IV Trials

Phase IV trials are usually conducted after a drug has been approved by the FDA. Phase IV trials provide additional information about the drug’s safety and/or efficacy.

4. What is a placebo?

A placebo is a substance or formulation (e.g., tablet, capsule, pill, liquid or powder) that has no treatment value. It is an inactive substance. In some clinical trials, experimental therapies are compared with placebo to determine if the experimental therapy is more effective than giving no therapy (the placebo).

5. What is informed consent?

Informed consent is the process of learning about the clinical trial through discussions with your physicians and deciding whether or not you want to participate. If you decide to participate in the trial, you will be required to sign a consent form. Remember, you are free to ask the research staff any questions before, during, and after the trial. And most importantly, you have the right to stop participation in the trial at any time.

6. What else should I know about clinical trials?

Here are some additional terms that you may need to be aware of when considering clinical trials:

Randomization: Randomization means that each patient has the same chance of being assigned to the investigational therapy group or the control group. Not all cancer clinical trials include randomization.

Control Group: A control group is a group of individuals or patients in the study who receive a standard treatment or placebo instead of the investigational therapy. Control groups are used in clinical trials that are designed to compare an investigational therapy to an existing standard of treatment or to placebo. The results from the investigational therapy group are compared to the results from the control group. Not all cancer clinical trials have control groups.

Single-blind study: In a single-blind study, the patient does not know whether they are receiving the investigational therapy or the control. Blinding only applies to randomized trials.

Double-blind study: In a double-blind study, the patient and the researcher/physician do not know if the patient is receiving the investigational therapy or the control. Blinding only applies to randomized trials.

Open-label study: In an open-label study, both the patient and the researcher/physician know which therapy the patient is receiving (investigational therapy or the control). Open-label studies are not blind and they may or may not be randomized.

Links
For further information regarding clinical trials, please refer to the following web sites:

• www.cancer.gov/clinical_trials, which is a service of the National Cancer Institute
  
  
• www.clinicaltrials.gov, which is a service of the U.S. National Institutes of Health
  

References:

1. National Cancer Institute
   
   
2. National Institutes of Health