Clinical trials are research studies that test new treatments for disease or new ways to use existing standard treatments. They can also help researchers better understand what causes a disease, how it affects the body, and how it may affect a person’s daily life.
Clinical trials must follow specific steps to make sure treatments are studied in a safe, careful, and reliable way.
If your child is eligible for a clinical trial, the research team will explain what to expect so you can decide whether to take part in the study.
Approval of the research plan
In a clinical trial, researchers develop and follow a detailed plan called a research protocol. This plan is designed to protect the health, safety, and well-being of participants.
In the United States, an Institutional Review Board (IRB) must review and approve most clinical trials before they begin. An IRB is a committee that includes doctors, scientists, and other experts who review the study. The IRB reviews the study and considers the potential benefits and risks to participants. After the clinical trial begins, the IRB continues to oversee the study. The IRB can approve or reject the study, request changes, or stop a trial if needed. Other scientific committees also review the study to make sure the research is well-designed.
Patient screening and eligibility
People who take part in clinical research are volunteers. A clinical trial can only include patients who meet certain requirements, called eligibility criteria, or inclusion and exclusion criteria.
Eligibility criteria are different for each clinical trial, and may include:
Type or stage of disease
Age
Overall health or other medical conditions
Previous treatments
Ability to follow the study plan
Your child’s care team will review the study criteria to see if the study may be a good fit. This process is called screening.
Eligibility criteria help protect patient health and safety and help ensure that the study results are meaningful. They can also help researchers learn whether a treatment works better for certain groups of people.
Informed consent
Informed consent is the process of learning about a clinical trial, understanding what to expect, and deciding whether to take part. A member of the research team will meet with you, explain the clinical trial, and let you know what to expect. They will go over:
Why the study will be done
Who can take part
How the trial may help you or others
Why your child may be a good fit for the study
Treatments and how often they are given
How the treatments differ from standard medical care
Tests and procedures that are done and how often
How long the trial will last
Possible benefits of treatments
Possible risks, side effects, or expected discomforts
Other treatment options if you choose not to take part
How your child’s safety and privacy are protected
Who to contact with questions or concerns
How information about the trial will be shared with you
What happens if you decide to leave the trial
It is your decision whether to take part in a clinical trial. You are not required to take part. You can leave the study at any time and still receive appropriate medical care.
If you agree to take part in the trial, you will be asked to sign an informed consent document. If the person participating in the trial is a child or is unable to give consent, a parent or legal guardian must provide written consent.
If you do not understand something, ask the research team to explain it in a way you understand. Be sure you have a chance to ask any questions you have and get a written copy of the study information.
Depending on your child’s age and level of understanding, they may be asked to agree to take part in the study (called assent). Assent means helping your child understand the study in a way that is appropriate for their age and giving them a chance to ask questions and share their feelings and concerns.
The research team will explain the trial to your child using age-appropriate words, pictures, or other tools. If a child is under age 18, a parent or legal guardian must still provide written informed consent. Younger children (often those under age 7) are generally not asked to give assent.
Your care team will partner with you to decide how much information to share and how to explain the study to your child.
Study enrollment and participation
If you choose to take part in a clinical trial, the research team will collect information before the study starts, sometimes called a baseline. This may include lab tests, surveys, exams, and other health information. These steps may be repeated during the trial to monitor your child and measure results.
During the clinical trial, your child may:
Be placed in a study group that gets the standard treatment or a study treatment
Receive a study treatment, such as a medicine, procedure, or medical device
Follow a specific plan or program
Have regular visits, exams, or lab tests
In some clinical trials, your child may be put into a group by chance (randomization). You cannot choose the group. In some cases, a study may use a placebo (a treatment that does not have the active ingredient), but this is not common in clinical trials for children. The exact procedures will depend on the type of clinical trial.
If your child needs treatment, they will continue to get appropriate medical care. In some studies, this may be the standard treatment instead of the study treatment.
The research team will monitor your child’s health and watch for side effects throughout the study.
Phases of clinical trials
Clinical trials are described by the phases of treatment development to reach the standard of care. Each phase has a different goal and answers different questions.
Phase 0: very small, early studies to see how a treatment (usually a medicine) might work in the body
Phase 1: tests a new treatment in a small group of people to learn about the best dose, side effects, and safety
Phase 2: uses a larger group of people to understand how well the treatment works and monitor side effects and safety
Phase 3: compares a new treatment to the current standard treatment
Phase 4: studies long-term effects, safety, and use after a treatment has been thoroughly tested and approved
The phases may vary depending on the type of clinical trial or what treatment is being studied. Doing research in phases helps protect participants and allows researchers to learn more about a treatment over time.
Phase 0 clinical trial
Researchers may give very small doses of medicine or treatment to see how it works in the body. At this phase, the goal is not to treat the disease but to learn more about the treatment. Phase 0 trials are very uncommon in children.
Questions answered by phase 0 clinical trials
How the body takes in a treatment or responds to it.
Does the treatment act as expected?
How does it work in the body?
Phase 1 clinical trial
In phase 1, researchers test the safety of new treatments or medicines, sometimes for the first time. A small number of people will participate. Researchers want to know whether the treatment is safe, the best dose to use, and any possible side effects.
Questions answered by phase 1 clinical trials
Is the treatment safe?
What is the highest safe dose?
How does it work in the body?
How should it be given?
What are the side effects?
Phase 2 clinical trial
Once the Phase 1 study has been completed and the information about side effects and the highest safe dose is available, the research team decides if the treatment should move to the next phase. Phase 2 trials test the treatment in more people and last longer. The goal is to see how well the treatment works (if it is effective) and to watch for side effects.
Questions answered by phase 2 clinical trials
Does the treatment work for a specific condition?
What effect does the treatment have?
What are the short-term side effects and risks?
How does the treatment work in the body?
Phase 3 clinical trial
Based on data from the Phase 2 study showing how well a treatment works and its safety, the research team decides whether the treatment should move to the next phase. Phase 3 trials test the experimental treatment in a large group of people. Researchers compare this treatment against a standard treatment, often by adding it, to see whether it improves the chances of a cure. Researchers also watch for short-term and long-term side effects.
Questions answered by phase 3 clinical trials
How does the new medicine or treatment compare to standard treatment?
How safe is it with a large group of people?
What are the short-term and long-term side effects?
How well does it work in different groups of people?
What is the best dose to use?
What are the benefits and risks of the experimental treatment?
Phase 4 clinical trial
Phase 4 trials are done after approval by health authorities, such as the U.S. Food and Drug Administration (FDA). The treatment is studied in larger populations over time. This gives important information about how effective and safe a treatment or medicine is for many different people.
Questions answered by phase 4 clinical trials
How does the medicine or treatment affect different groups of people over time?
How well does it work in the “real world”?
What are the long-term benefits?
What are the long-term risks?
How is the treatment used in medical care?
Does it interact with other medicines or treatments?
How does the treatment affect a person’s long-term health and quality of life?
What are the costs of treatment?
Trial completion and transition of care
When the clinical trial ends, your child may have a final visit to collect more information or do additional testing. This provides information on treatment effects. This visit may include:
Physical exam, lab tests, questionnaires, or other measures
Learning about next steps for your child’s care, such as returning to your regular doctor (transition) or planning for ongoing care
Planning for future check-ins, if needed
Learning how and when the study results will be made available to you
After the trial is completed, the research team will:
Analyze the clinical trial results
Report findings and share results when they are ready
Store data securely for future use
It can take months or even years for the results of a clinical trial to become available.
Participants may continue to be monitored after the trial ends. Depending on the study, follow-up may continue for several years.
Key points about steps of a clinical trial
Clinical trials test new treatments or new ways of using standard treatments to learn if they are safe and effective.
Before a clinical trial begins, an Institutional Review Board (IRB) reviews the trial plan to make sure it is safe, ethical, and protects patients’ rights.
Only certain patients who meet specific criteria can take part in a clinical trial.
Informed consent means that patients must learn about the clinical trial, including potential benefits and risks, before they decide to participate.
Patients can leave a clinical trial at any time.
Clinical trials have different phases, which can help keep patients safe and allow researchers to learn about a treatment over time, including how it works, side effects, and long-term risks and benefits.
