With any new medical procedure, clinical trials need to be undertaken before medical professionals can make the new treatments available to the general public. This is, indeed, the case with gene therapy. Gene therapy clinical trials are intended to assess the efficacy, safety, and reliability of gene therapy treatments to aid in the care of chronic illnesses.

Patients who feel they are desperate to try any new treatment in the hopes of a cure or more effective management may voluntarily take part in medical tests such as gene therapy clinical trials. Most often, these patients are given either true treatment or a placebo, and are monitored for any unpleasant side effects. The relative effectiveness of the treatment is also assessed, and using the information garnered by the clinical trials, scientists and doctors are able to calculate the risk benefit analysis to determine if the new therapy is a good option for general use with other patients.

When there is a shortage of volunteer patients, or when the treatment is determined to be too new or too risky for human test subjects, animals or computer modeling may be used in their place. When animal subjects are used, scientists use essentially the same procedure as they do for humans. Instead of the patient being unaware of whether or not they have been given the placebo, it is the researchers themselves who are kept ignorant. This is generally referred to as a double blind study, and is intended to prevent unintentional swaying of the results in one direction or another.

Because gene therapy is such a new procedure, it is important that it be thoroughly tested before it becomes available as part of the regular roster of treatments. Gene therapy is generally targeted toward chronic, debilitating illnesses such as Parkinson's disease and multiple sclerosis. These are serious disorders and patients and their families are often highly emotional in their quest for a cure. It is imperative that scientists overseeing the clinical trials remain as impartial as possible during the testing, and not unintentionally corrupt the results in their hopes of finding a cure.