Frequently Asked Questions about Clinical Trials

What are clinical trials?

Clinical trials are scientific inquiries designed to investigate new medications, procedures, and treatment regimens. Before any medical intervention is approved for human use by the Food and Drug Administration (FDA), it must go through extensive testing to determine that it is safe and effective. Our research staff has conducted dozens of clinical trials that have helped lead to the approval of revolutionary medications and treatments for various diseases of the liver and gastrointestinal tract.

The FDA approval process takes a very long time. Before they are deemed safe for human use, experimental drugs must first pass pre-clinical tests in animals. After that, the drug may enter clinical trials, which typically occur in 4 phases:

  • Phase I – testing of the drug on 20-100 healthy volunteers to determine the appropriate dose and to check for safety
  • Phase II – testing of the drug at different doses on 100-300 patients to see whether or not the drug is effective and safe
  • Phase III – extensive testing of the drug on 300-3000 patients to further understanding of the drug’s efficacy, safety, and side-effect profile
  • Phase IV – after FDA approval, the drug undergoes post-marketing surveillance to watch the drug’s long-term effects, compare it to existing treatments, and determine its cost-effectiveness

In the Gastroenterology and Hepatology Clinical Trials Unit, most of the clinical trials we offer are in Phase II or Phase III.

Do I qualify for a clinical trial?

Each clinical trial we offer is a little bit different, using different drugs or targeting disease at different stages. Therefore, the eligibility criteria for each study can vary considerably.

Contact our Clinical Trials Unit to see if we have a clinical trial that you might qualify for. If you qualify for more than one, we will help you decide which trial is the best for your individual situation.

What can I expect if I agree to participate?

Clinical trials are a commitment and typically require active participation. If you agree to try a clinical trial, you will be scheduled for a screening visit. During this visit, you will have the opportunity to learn everything you need to know about the study and if you decide to participate you will be asked to sign an informed consent form (ICF). A variety of tests, such as blood tests, an electrocardiogram (EKG), and body measurements may be performed and you may be required to fill out some questionnaires and a detailed medical history. You may also meet with a study doctor, who will examine you. If necessary, additional tests such as an MRI or ultrasound may be performed. Once all of the results are completed, a final determination of eligibility is made.

If you are determined to be eligible, you may be randomly assigned to one of several treatment groups. Typically, a clinical trial has one or more groups that actually receive the study drug, and a placebo group that receives an identical version of the study drug, but without the active ingredient. These trials are usually “double-blind,” meaning that neither you nor the research team will know which group you are in until the end of the study. In cases of emergency, the team will be able to un-blind the treatment and learn which group you are in.

The lengths of clinical trials can vary considerably, from a single visit to several years. Typically, you will come in more frequently during the first year and then less frequently thereafter. You will be expected to attend your study visits diligently, take your prescribed medications faithfully, and inform your study doctor of any changes to your health.

What are the benefits of participating in a clinical trial?

Since the study drugs are still in testing phases and some participants may receive a placebo, there is no guarantee that patients will benefit from participation. Participants may benefit from the close monitoring of their health.

Participating in a clinical trial contributes to medical research and scientific discovery that could help people in the future. UC Davis has participated in dozens of clinical trials that have helped lead to the FDA approval of revolutionary medications, such as the new generation of hepatitis C direct-acting antivirals and obeticholic acid, the first new therapy approved for primary biliary cholangitis in almost 2 decades.

What are the costs of participating in a clinical trial?

All study visits, tests, and procedures are paid for by the study. Neither the participant nor their insurance is billed for any study-related procedure. For many studies, the cost of time from work and travel costs are compensated.

What are observational studies?

Some clinical trials do not directly test drugs or interventions. These observational studies track patients’ health and disease during their normal course of care. In addition, observational studies may collect blood or other tissue for investigations into the causes of disease or response to treatments. Observational studies may involve a single blood draw or have a set visit schedule like clinical trials. Some observational studies are registries in which the participants’ medical records are monitored for changes in treatment and health outcomes.