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How a Clinical Trial is Planned

Before a clinical trial begins, a new therapy is often developed and tested in a laboratory. It's then thoroughly tested in animals. If this early research (the preclinical testing) shows promise that the therapy may be safe and effective, a carefully planned and monitored clinical trial of the drug or treatment will be conducted in people.

Doctors who specialize in cancer research develop and lead cancer clinical trials. They determine the study's protocol (procedures and design), including:

  • the disease to be treated
  • the treatment to be tested
  • the study goal(s) (sometimes called endpoints)
  • the type of patient who will be an appropriate participant
  • the methods to be used to protect the participants' safety
  • how much medicine or other treatment will be given to patients
  • how long the treatment will be studied

A trial can take place at a few specific locations or be conducted from many venues across the United States. In many cases, participants can be treated at various locations, which may include a large cancer center, a university hospital, a clinic, a local medical center or the doctor's office.

Clinical Trial Phases

A cancer clinical trial is divided into four parts, called phases, each with a specific purpose. As each phase is successfully completed, the trial moves into the next phase.

Phase I

In phase I, treatment is tested in a very small group of patients to determine:

  • its safety
  • the appropriate dose (amount)
  • the best way to administer the treatment

Researchers watch patients closely for possible treatment side effects.

Phase II

In phase II, treatment is tested in a larger group of patients to determine:

  • whether the treatment works
  • how well the treatment works

Researchers continue to monitor patient safety in phase II and throughout the trial.

Phase III

Phase II studies with positive results will move into phase III. Phase III trials are "radomized." This means a "treatment group" is compared to a "control group." In a randomized trial:

  • the treatment group is made up of large numbers of patients who receive the study treatment
  • the control group is made up of large numbers of patients being treated with the best standard treatment
  • the treatment outcomes for the two groups are compared at specific time intervals

The U.S. Food and Drug Administration approves a treatment if it passes phase III testing. The treatment must meet safety requirements and be either more effective than standard treatment or equally effective as standard treatment but with less toxic side effects.

Phase IV

By the time a clinical trial enters phase IV, the FDA has already approved the treatment. Phase IV studies are often performed to:

  • identify an additional use for an already approved drug or other treatment
  • gather additional safety and effectiveness information from a larger group of patients
  • establish effectiveness in a subgroup of patients, for example, patients over age 65

Differences Between Clinical Trials and Standard Treatment

  • Patients' responses to treatment are followed closely in a study. Patients may receive more tests during treatment and have more doctors' visits as part of the clinical trial than they would in a standard care setting.
  • Treatment routinely covered by health insurance or managed care plans may no longer be covered for patients enrolled in clinical trials. In some plans, coverage for patients receiving treatment as part of a clinical trial is set up differently. See Clinical Trial Insurance Issues.
  • Patients may not know whether they're receiving the study treatment or the best standard treatment. Many cancer clinical trials compare two patient groups. However, federal regulations require that patients be told if a placebo (a substance that looks the same as the treatment but is inactive) will be used in a trial. Placebos are not typically used with patients in cancer clinical trials.

Are Clinical Trials Safe?

U.S. clinical trials are designed to give patients the safest, potentially most effective clinical therapies. The trials are conducted once researchers have shown in the laboratory and in animal research that a particular study treatment has a good chance of offering better outcomes for people with a specific disease.

All trials follow strict scientific and ethical principles. Every clinical trial has an action plan, called a protocol. The same protocol is used by every doctor at each treatment center taking part in the trial.

Several processes are in place to ensure that trials are safe for patients, provide oversight and monitor trial protocols to make certain that study risks don't outweigh potential benefits and that randomization of treatment groups is conducted fairly and ethically.

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last updated on Tuesday, March 15, 2011

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