Understanding Clinical Trials

CURE, Fall 2011, Volume 10, Issue 3

A primer on cancer clinical trials.

Clinical trials provide data that may prove a new experimental treatment is better than the standard therapy. They offer a source of hope if you have few options or if you’re seeking treatments with the potential to be more beneficial than the standard, one with fewer toxicities or one that is more convenient, such as oral medication or shorter treatment times. You may also be motivated to join a clinical trial to further cancer research and help future cancer patients.

Although an increasing number of investigational cancer drugs are being approved by the Food and Drug Administration each year, the process of drug testing and approval is still lengthy and complex. Most clinical research of a new drug progresses in an orderly series of steps, called phases.

Phase 1 trials enroll a small number of patients and evaluate how a new treatment should be given (for a new drug, taken orally or injected into the blood or into the muscle), how often it should be administered and the most effective dose with the fewest and least severe side effects. Many patients who enter phase I trials have limited therapeutic options or do not improve with standard therapies. The primary goals of phase I trials are studying side effects and establishing a safe dosage.

Phase 2 trials continue to test the safety of a treatment and also begin to evaluate how well it works. These trials are usually limited to a specific cancer that showed benefit with the treatment in earlier trials.

Phase 3 studies either test an experimental drug, combination of drugs, regimen of radiation therapy or surgical procedure in comparison with the current standard. Enrollment is often in the hundreds to thousands across multiple locations, and the treatment is more likely to be effective. Typically, a participant is randomly assigned to the standard treatment or the new treatment (called randomization). Those patients who are not randomized to the experimental treatment will receive the best standard treatment available.

Remember, since the treatment is experimental, the outcomes and side effects are not always foreseeable, although any predicted risks should be explained to you in detail beforehand. In most trials‚ the therapy under investigation is provided at no cost to the trial participant.