Clinical trials are specific therapy regimens designed by scientists and physicians to evaluate promising new treatments. Each trial requires approval by the Federal Drug Administration (FDA) and other external regulatory bodies. Clinical trials determine whether a new prevention, diagnostic or treatment regimen may be more effective than standard regimens, comparing carefully defined criteria such as safety, side effects, and period of remission or recurrence. Results cooperatively generated by participating clinical research centers worldwide are collated, thus providing the large numbers of study participants necessary to produce the diverse sample population required for reliable evaluation.

There are four progressive clinical trial steps  in the life of a drug before it becomes the dominant standard treatment for a specific type and stage of cancer.

Phase I Trials, the earliest investigational step, are designed to identify safe dosage levels and the best means for administering the treatment (pill form, through I.V. drips, or shots). Patients in Phase I trials generally have advanced cancers for which no effective standard treatment exists, or the standard regimen is unlikely to succeed.

Phase II Trials include patients who may or may not have already had standard treatments for their types of cancer. Eligibility of previously treated patients may depend on the type and amount of prior treatment as well as other factors. Phase II trials focus on the effectiveness of the trial regimen, but are not designed to directly compare the results of the experimental treatment to standard treatment.

Phase III Trials compare effectiveness of the new regimen with the current standard of care for the specific type of cancer being studied.  They also evaluate side effects of the new treatment with those of the standard regimen.  If the new regimen proves more effective and/or has fewer, more tolerable side effects, it may replace the old standard of care.

Phase IV Trials continue studies of a drug regimen after it has been established as the new standard of treatment for a specific type or stage of disease.  This post-marketing phase assures that the newly established standard of treatment continues to prove both safe and effective.

Participation in clinical trials is entirely voluntary. If your physician believes you might benefit from a specific trial, he will fully explain its possible benefits, risks, and eligibility criteria and answer any questions you may have.  You will also receive an Informed Consent Form describing all known possible risks and benefits, eligibility requirements, dosage scheduling/frequency, duration of the trial and any other factors you should know before deciding to enter a clinical trial or not.

In general, clinical trial participants are more rigidly monitored than patients receiving standard treatments in which efficacy and side effects are well known.  You should consider that clinical trials often require more testing, and thus may be more time-consuming.  Also, before you decide to enter a trial, check with your health insurer to learn what will or will not be covered. Most insurers will not cover costs of tests considered “over and above” what would be done if you were on standard treatment in which there are no stringent reporting requirements as there are in clinical trials.  However costs of drugs and required extra tests in clinical trials are often covered by the trial sponsor (a pharmaceutical company or national or international study group).

For a more detailed description of clinical trials, visit the National Cancer Institute’s very user-friendly website at This website contains extensive information on cancer in general, medical terms, lists of trials at different sites around the country, support services, and many other cancer-related topics. The NCI Cancer Information Service (1-800-4-CANCER or 1-800-422-6237) is also available and provides callers the opportunity to ask questions and discuss any concerns they may have.