A clinical trial is a research study used to evaluate the efficacy and safety of medicines, and for improving health in humans.
Usually, a research study is developed with a selected group of people (aka Volunteers) that meets a study criteria and which voluntarily and individually decides participate in such study 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 usually conducted in three phases (I, II, III). Only a small number of people participate in phase I trials while the later phases involve a larger number of volunteers.
There are four types of clinical trials designed to answer different research questions that are divided in four phases according to its complexity.
What are these phases?
Phases I, II, III and IV.
Phase I: To assess the safety and side effects of a new drug or treatment in a small group of people for the first time. Usually the patient has to remain in the clinical setting for one or more days.
Phase II: After evaluating a new drug or treatment in Phase I, this needs to be tested in a larger group of people to confirm its effectiveness, safety, and side effects, that is Phase II.
Phase III: After the drug or treatment has passed phases I and II, their efficacy and safety is proved in a larger group of people. Moreover, in this third phase , the new drug is compared to commercially existing and available treatments in the market.
Phase IV: This phase is to assess positive and negative effects of a drug that is already marketed and available to the entire population. In such studies , the researcher seeks the long-term effects associated with the new drug or treatment.
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.
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:
In some studies, participants receive a physical examination and their medical histories are reviewed by either the study physician or a research staff member once they are enrolled in the study. The 'health will continue to be monitored during and after the trial. A detailed description of what's expected of volunteers will be outlined in consent forms along with specific clinical trial information.
Volunteers in a clinical trial participate in the development of medical therapies that may offer better treatments and even cures for life-threatening and chronic diseases. However, there are risks involved.
Possible benefits for volunteers:
Possible risks for volunteers:
Please note: Volunteers may withdraw from a study at any time for any reason.
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.
Informed consent is a process where the Investigator or Clinical Coordinator, explain to volunteers the risks and benefits of participating in a study, the duration, and the conditions required for the patient to qualify. Once all questions have been answered, the patient decides whether to accept or not to participate in the study. As mentioned above, any volunteer can leave the study at any time for various reasons.
For more information about the informed consent process when participating in clinical trials, please refer to Understanding Informed Consent.
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.