A clinical trial is a research study in which volunteers receive investigational treatments under the supervision of a physician and other research professionals. These treatments are developed by pharmaceutical and biotechnology companies who select qualified physicians, also known as investigators, to conduct clinical trials to determine the benefits of investigational drugs.
Clinical trials are studies performed with human subjects to test new drugs or combinations of drugs, new approaches to surgery or radiotherapy or procedures to improve the diagnosis of disease and the quality of life of the patient.
All clinical trials have guidelines about who can participate. Before joining a clinical trial, a volunteer must qualify for the study. The factors that allow volunteers to participate in a clinical trial are called “inclusion criteria” and the factors that disallow volunteers from participating are called “exclusion criteria.” These criteria can include age, gender, the type and stage of a disease, previous treatment history, and other medical conditions.
Some research studies seek participants with specific illnesses or conditions to be studied in a clinical trial, while others require healthy participants. It is important to note that inclusion and exclusion criteria are used to identify appropriate participants, promote participants’ safety, and ensure that researchers learn the information they need.
In a clinical trial, a volunteer is usually assigned a specific study group. Volunteers in one study group may receive an investigational treatment or study drug while other volunteers may receive a placebo or a treatment already available.
A placebo is an inactive product used to assess the experimental treatment’s effectiveness. The participant, physician, and research staff may not know which volunteer receives a placebo and which receives the active treatment. Not knowing which participants are receiving the active treatment allows the physician and research staff to objectively observe the volunteers during the study. Regardless of which treatment volunteers receive, however, the level of medical attention and care that each receives is the same.
None of the existing treatments result in a cure of all patients, nor are they without side effects, and doctors continue looking for better ways to treat the disease.
Clinical trials are also organized into different phases of research, in order to build up a greater understanding of the new treatment, before it is approved or recommended for routine use.
Phase I – the first studies in humans are Phase I trials. They are performed with small numbers of patients or healthy volunteers and are used to answer questions such as what dose of the drug is likely to be effective and what side effects might occur.
Phase II – these trials continue this process with larger numbers of patients. They have a greater focus on how well the treatment or procedure works, perhaps in particular situations or groups of patients.
Phase III – these trials enroll large numbers of patients and are used to compare the effectiveness and safety of the new treatment with that of the standard existing treatment. Information obtained from large Phase III trials that demonstrate the benefits a new drug over the existing treatments is sometimes presented to regulatory authorities in order to obtain a license to market and sell the drug.
Patients considering participating in a clinical trial should talk about it with their physicians and medical caregivers. Potential volunteers should also understand the credentials and experience of the staff and the facility involved in conducting the study.
Questions to ask a physician or medical caregiver for any clinical trial.
- How long will the trial last?
- Where is the trial being conducted?
- What treatments will be used and how?
- What is the main purpose of the trial?
- How will patient safety be monitored?
- Are there any risks involved?
- What are the possible benefits?
- What are the alternative treatments besides the one being tested in the trial?
- Who is sponsoring the trial?
- Do I have to pay for any part of the trial?
- What happens if I am harmed by the trial?
- Can I opt to remain on this treatment, even after termination of the trial?
You will never be enrolled in a clinical trial without being asked first and also having given written consent to take part. However, you can, for any reason, decide not to continue to take part in the trial and your doctor will then offer you the existing treatment for your particular condition.
You can withdraw from a clinical trial, without explanation, at any time.
Access to personal information is usually available to the investigator and research team conducting the clinical trial. In some circumstances, the IRB overseeing the research and the sponsor or contract research organization coordinating the trial will also have access to personal information. This is explained more specifically in the consent form that participating volunteers are asked to sign. As a clinical trial progresses, researchers report the results of the trial at scientific meetings, to medical journals, and to various government agencies.
After a study phase is complete, the data is collected to determine the drug’s effectiveness, if it is safe and if there are any side effects. Depending on the results, researchers then determine whether to stop testing or move to the next phase of study. After phase III of a study is complete, researchers decide if the results are medically important and may submit them to journals for peer-review. Data then may be submitted to the Food and Drug Administration (FDA) for approval.
If a drug is approved, pharmaceutical companies may continue to conduct studies that compare the new drug—in terms of its safety, effectiveness, and cost—to other drugs already on the market or assess a drug’s long-term effectiveness and its impact on the quality of a person’s life.