Volunteers sustain clinical trials

By Christy Oglesby
CNN

(CNN) -- They swallow pills, receive injections and inhale vapors -- sometimes blindly, and unsure if they'll be healed or harmed. Tens of thousands of people volunteer in federally and privately funded clinical trials each year.

Some are seeking cures while others are just willing to serve as canaries in the medical coal mines to help mankind. But how do people find the trials and why are such trials divided into phases? How do those phases differ and who regulates clinical trials? Will there be compensation and what recourse is available if something goes awry?

Understanding trials

Researchers design clinical trials in order to develop therapies, discover new ways to use old treatments and answer specific questions about drugs. Pharmaceutical companies conduct laboratory research on animals and human cells to determine a compound's effectiveness. If those tests are successful, the company applies for approval from the U.S. Food and Drug Administration to begin tests in humans.

MORE STORIES Alzheimer's vaccine passes key test     RESOURCES For more information on cinical trials, visit   • Clinicaltrials.gov   • CenterWatch

The trials have established guidelines that determine who may participate. Age, medical history, current physical condition and disease type are factors included in the guidelines. Some trials seek healthy participants while other researchers solicit volunteers who have the disease they are studying. Generally, healthy people participate in phase one studies and those involving vaccines.

Before final approval, drugs must go through three phases of testing. Phase one determines if a drug is safe for use in humans and typically involves a small number of paid volunteers, perhaps 20 to 100. Researchers assess what happens to people who take the drug -- its side effects, absorption process and excreted byproducts. About 70 percent of drugs pass this testing phase.

Phase two might last from several months to several years. Researchers test a drug's effectiveness, using several hundred patients. One group receives the experimental drug, while a control group gets a placebo. In so-called "blind" studies, neither patients nor researchers know who is getting what. That process allows the drug company and the FDA to compare information about a drug's efficacy. About one-third of drugs meet the standards of a phase two trial and move to phase three.

Phase three is similar to phase two but involves more patients and lasts several years. Several hundred or several thousand people take the experimental drug. Researchers and the FDA acquire an in-depth knowledge of side effects, effectiveness and drug benefits. If phase three ends successfully, the company requests FDA approval to market the drug.

Although the FDA will have approved a drug, the federal agency continues to monitor its use and effects, during phase four. Pharmaceutical companies compare their product to similar drugs on the market and monitor impact on a patient's quality of life and the drug's long-term effectiveness.

Answers to common questions

Some studies pay for participation in clinical trials and others do not. And those who participate should continue to receive care from their primary medical provider.

Two important safeguards exist to protect patients. An institutional review board must approve any study conducted by researchers who have grants from pharmaceutical companies or the National Institutes of Health. That review board examines the study's protocol to make sure patients will not incur any undue risk.

And clinical trial participants in the United States must sign an informed consent document, which explains risks and states that the patient may withdraw from the trial whenever he or she wants to.

Trials couple risks with benefits. Participation in a clinical trial exposes patients to treatments that may not be widely available and might even be better than their current therapy.