WHAT IS A CLINICAL TRIAL?
A clinical trial—a critical part of developing a new drug, biologic, or medical device—is a research study conducted in human participants to test a potential treatment for safety, effectiveness, dosing, and more. During clinical trials, while the treatment is still being studied, it's referred to as "investigational." Regulatory authorities use trial data and other information to decide if a new product is safe and effective and can be approved for use.
Investigational drugs require clinical research before they can be brought to market. Many study drugs don't meet the criteria for approval. But whether or not an investigational treatment is ultimately approved, the clinical trial process helps researchers learn more about a disease and its diagnosis, prevention, and potential treatment.
Clinical trials depend on volunteer participants to help provide the scientific evidence for determining whether an investigational drug is safe and effective. This is especially important with rare diseases, as it can be challenging to find enough patients to gather meaningful data.
Clinical trial participation offers an opportunity to be part of something bigger: research that may advance understanding of a disease or help get a new treatment approved.
ENROLLMENT IN A CLINICAL TRIAL
Every clinical trial follows a uniquely defined protocol for how the research will be conducted and has specific eligibility criteria for participants—such as age, sex, disease severity, and more.
Talk to your doctor to determine if a particular trial could be a good match for you or a loved one. Once you apply, trial staff use a screening process to determine and finalize participants. Not everyone who applies for a clinical trial will be selected to participate. Each clinical trial has defined inclusion and exclusion criteria within its protocol. Participants must meet these criteria to be eligible for enrollment in the trial. Learn more.
The process of communicating risks and other key information of a clinical trial to ensure that selected participants can make an educated decision about trial participation.
THE TRIAL PROCESS: WHAT TO EXPECT
Deciding about a clinical trial can be both exciting and overwhelming. While each trial is different, there are some common elements you can expect:
- Trial staff will provide information about the study’s risks, logistics, and more during the informed consent process, to help you make an educated decision about participation
- Trial lengths vary depending on what is being studied—some are very short, others include long-term follow-up
- Participants may need to travel, stay in hospitals, or undergo more tests and exams than if they were not in the study
- Participants may be asked to keep a health log, fill out forms, or provide other types of reporting
- Once you choose to participate, you'll sign the informed consent document to indicate you understand fully; this is not binding—participants may leave a trial at any time
An investigational treatment may or may not be safe and/or effective. And in some trials, for comparison purposes, some participants may receive a placebo rather than the investigational treatment for some or all of the study period.
Even if the trial doesn't improve participant outcomes or the investigational drug isn't ultimately approved, all clinical trial participation may add value to medical knowledge.
FREQUENTLY ASKED QUESTIONS
What are the four phases of clinical trials?
The clinical trial process typically follows four specific steps, or phases, which help researchers collect different types of information about the drug being studied.
As you review potential trials, you'll see them designated by their phase number. You may enroll in any phase of a trial for which you're eligible, with no requirement to participate in previous or subsequent phases. Trial phases are sometimes combined into a single study, so you may see some trials designated by more than one number, such as Phase I/II or II/III.
- Phase I – Testing with a small group of volunteers to better understand the investigational treatment's safety profile, including side effects
- Phase II – Testing with a larger group of patients with the disease or condition, to gather preliminary data on whether the investigational drug works and to collect additional safety information
- Phase III – Testing with a larger group of patients with the disease or condition to gather more information about an investigational drug's safety and effectiveness, and sometimes to compare it with current or similar treatments
- Phase IV – Testing carried out after a treatment has been approved to gather additional information about its safety, effectiveness, or optimal use
Note that the number of participants in clinical trials for investigational drugs that treat rare/orphan diseases is often small.
How do I enroll myself or my child in a trial?
Once you and your doctor have identified an appropriate clinical trial, you may contact the study organizers; contact information will be included with each trial's details. The organizers will set up an appointment to determine whether you or your child meets the eligibility criteria.
Once eligibility is confirmed, you will be provided with an informed consent document, which provides specific information about the trial, including:
- How the study will be conducted
- Specific participant requirements
- Potential risks and additional information related to trial participation
- Study duration
- Cost to you, if any
- Payment to you, if any
- Names and phone numbers of key contacts
The informed consent process exists to help ensure that trial participants can make an educated decision about participation. Before you sign the informed consent document, be sure to discuss anything that's unclear to you with the study organizers and/or your doctor. Remember that the document is not binding, and participants may leave a trial at any time.
How long do clinical trials last?
Timeframes vary based on the trial. Some are very short, while others continue for years to ensure long-term follow-up. This information is included in the informed consent document provided to prospective participants prior to enrolling in a trial.
Are trial participants paid?
Not all studies compensate participants for their time, nor do they reimburse all costs a patient or family may incur as a result of participating in a trial. For information on a specific trial, you should review the informed consent document created for that particular trial, as well as other information provided to you by the clinical trial site or investigator, which will outline the costs, reimbursement, and compensation available for a study.
Does trial location matter—is travel ever required or possible (such as if a suitable trial cannot be found locally)?
Each trial is different, and the specific eligibility requirements will dictate whether geography is a factor. As you review potential trials, you'll find information about location. Many trials have study sites across multiple locations and countries.
Most trials require regular medical procedures, medical tests, and sometimes hospitalizations. It may be possible to travel to a non-local study site, but keeping up with trial requirements may be difficult if participants live far away. Your doctor and the study organizers can help determine if a trial's locations and travel requirements are suitable for you or your loved one.
Do trial medications always work?
No. Clinical trials provide the basis for the development of new potential treatments. The safety and/or the effectiveness of the investigational drug is not always fully known at the time of the trial, which is why it's important to study these investigational drugs in specific groups of volunteers. Not all investigational drugs are found to be safe and/or effective, and the decision to participate in a clinical trial is a personal one that should be made in partnership with your or your loved one's doctor.
In addition, depending on the trial design, some participants may get a placebo (a substance that has no active ingredient, such as a sugar pill) for part or all of the study, which gives researchers something to compare with the study drug. To reduce bias and promote objectivity in study results, participants are usually assigned randomly to receive either the study drug or placebo. Neither participants nor researchers know what each participant is getting prior to or during the trial. This approach is called a "randomized, double-blind study."
Are there risks involved in participating in a trial?
Yes. While clinical trials may offer the chance to try an investigational treatment, there are also risks to consider:
- The investigational treatment may have side effects—including potentially very serious ones.
- The investigational treatment may not work for everyone in the trial.
- In some trials, some participants may get a placebo (a substance that has no active ingredients, such as a sugar pill) for part or all of the study, to allow for objective comparison with the study drug. Usually, participants are randomly assigned, and both before and during the trial neither participants nor researchers know what each participant is getting; this is referred to as "blinding."
- The routine for the investigational treatment may take more time or be more complicated than what the participant is used to. For example, participants may need to get regular tests, have frequent check-ins with the study site, stay in a hospital, or follow a plan for taking the study drug.
During the planning stages of a clinical trial, regulatory authorities work to ensure that proposed trials do not place participants at extreme risk or harm. Nevertheless, anyone considering participating in a trial should carefully discuss potential risks with their doctor.
How are clinical trials regulated to safeguard participants?
Regulatory authorities—such as the FDA (Food and Drug Administration) in the U.S.—set standards and structures for the clinical trial process, especially around informing and protecting participants. Study organizers are responsible for designing clinical trials that are thoughtful and ethical, and may seek additional guidance from regulators throughout the trial process.
Before a clinical trial is initiated, its protocol must be reviewed and approved by a group of experts called an Institutional Review Board (IRB), made up of doctors, researchers, and members of the community. At the start and all through the research, the IRB helps ensure that the study is ethical and the rights and welfare of participants are protected.
During a trial, results may be reviewed by an independent team of experts called a Data Monitoring Committee (DMC) or Data Safety and Monitoring Board (DSMB), who check for any concerns related to drug safety. The DMC or DSMB can recommend to regulatory authorities or the researchers that the trial be stopped at any time if the study is not effective, is harming participants, or is unlikely to serve its scientific purpose.
What do clinical trials measure?
All clinical trials have defined "endpoints"—specific criteria for measuring the potential benefit of an investigational treatment and evaluating the trial’s results. Typically, researchers use one of two types of endpoints:
- Clinical endpoints are generally the most reliable way to measure response in clinical trials. They directly measure the ability to feel better, function better, or live longer.
- Surrogate endpoints use biomarkers to indirectly measure an investigational drug’s effect. A biomarker is a physical, biochemical, or genetic characteristic that can be objectively measured. Surrogate endpoints use biomarkers that are believed to be reasonably likely to predict a clinical benefit.
What happens when a trial ends—can participants continue getting the medication?
When a trial ends, the data collected during the study is analyzed to assess how participants responded to the investigational treatment. Reports are then sent to regulatory authorities to determine appropriate next steps.
Access to study treatment after completion of a clinical trial varies. In some cases, trial participants can continue to receive the investigational treatment in an extension of the original trial, or in a separate, long-term trial. However, this is not always the case. Ask about this when considering whether or not to take part in a trial.