OHSU

What are Clinical Trials?

Clinical trials are research studies in which people help doctors find ways to improve health and cancer care. Each study tries to answer scientific questions and to find better ways to prevent, diagnose or treat cancer. Unless people participate in clinical trials, doctors cannot develop new or improved cancer treatments.  Our doctors are committed to conducting clinical trials with the goal to improve care for every person who develops cancer.

Who can participate in a clinical trial?

Each study has its own guidelines for who can participate. These are called eligibility criteria. To ensure the strongest results, researchers want people who participate to be alike in certain ways. To be eligible for a clinical trial, you might need to have a particular type and stage of cancer, be the right age or gender for the study or have had certain previous treatments. The eligibility criteria are included in the study plan. To find out if you are eligible for a particular study, talk to your doctor or the person in charge of enrolling patients for the study.

Why would I want to participate in a clinical trial?

Potential benefits of participating in a clinical trial include:
Access to new drugs and treatments before they are widely available.
Being among the first to benefit if a new approach is found to be helpful.
Making a valuable contribution to cancer research.
Helping doctors treat cancer patients more effectively in the future.

Types of Clinical Trials

  • Cancer Treatment
  • Prevention
  • Screening Detection and Diagnosis
  • Supportive Care
  • Observational Population Studies

Clinical Trial Phases

Most research that involves testing a new drug progresses in an orderly series of steps, called phases. This allows researchers to ask and answer questions in a way that gives them reliable information about the drug and protects the patients. Most clinical trials belong to one of three phases:

  • Phase I trials
  • Phase II trials
  • Phase III trials

In addition, after a treatment has been approved and is being marketed, the drug's maker may study it further in a phase IV trial. <link to rollover definition/glossary:  The purpose of phase IV trials. A phase IV trial involves thousands of people.

Where do the ideas for trials come from?

The ideas for clinical trials often originate in the laboratory. Researchers develop a clinical trial protocol (the plan for a trial) after laboratory studies indicate the promise of a new drug or procedure. The first trials of a particular drug or procedure focus on safety (phase I). Later trials focus on whether the drug or procedure is effective (phase II or phase III).