If you’re living with thyroid eye disease (TED), you may be considering joining a clinical trial. During these studies, researchers evaluate new options for treating, diagnosing, or helping prevent TED.¹ Understanding all the terminology related to research participation can help you make informed decisions about clinical trials.

Check out 10 clinical trial terms that will help you better evaluate whether you want to participate in a trial for TED, an autoimmune disease that’s also called Graves’ orbitopathy or Graves’ ophthalmopathy.²

1. Clinical Trial Phases

If you’re interested in joining a clinical trial for TED, you should understand the phase of the trial you’re considering. Clinical trials are broken down into phases to describe the stage of research.

• Phase 1 — A small group of people will be evaluated to confirm the overall safety of an investigational study drug.³
• Phase 2 — A larger group of people will be evaluated to determine whether the investigational study drug is safe and which side effects it might cause.³ Different doses are also tested during this phase.⁴
• Phase 3 — An even bigger group of participants is evaluated. Some participants might receive an inactive treatment (placebo) or the current standard treatment.³ The U.S. Food and Drug Administration (FDA) usually determines if an investigational study drug should be approved after a phase 3 trial.¹
• Phase 4 — After the study drug is approved by the FDA, researchers continue to study it. They’ll keep reviewing outcomes, side effects, and other data from people in the general public who have been prescribed the medication.^1,3

2. Clinical Trial Eligibility

Not everyone with TED will be eligible, or able, to join a TED clinical trial. Every study looks for people with certain characteristics based on what the researchers want to learn.³

To decide which participants should join a trial, the study investigators use a screening process to determine who may be eligible for it.³ For instance, some studies may only enroll people with severe TED, while others may only enroll those with mild symptoms.

To decide if you’re eligible to participate, you may be asked if you currently have TED symptoms, such as dry eyes, double vision, or bulging eyes.⁵

3. Informed Consent

If you’re eligible to join a clinical study for TED, you’ll be advised on what the study is about, and you’ll have the opportunity to ask questions and get answers from the people running the study. You can also talk to your primary health care provider, ophthalmologist (eye doctor), family, friends, and anyone else who can help you make your decision.⁶

Once you’re comfortable with the information, you’ll be asked to provide informed consent, which is a confirmation that you’re willing to be part of the trial. This typically involves completing an informed consent form and signing it.³

4. Institutional Review Board

An institutional review board, or IRB, is a group of independent experts who monitor clinical research projects that study human beings.^3,7 The board’s job is to ensure everyone participating in the study remains safe. The IRB, also called an independent ethics committee, ensures that participants’ rights are protected and monitors their well-being while they’re in the study.³

Investigational study drugs are always reviewed by an ethics committee for testing in humans.⁸

5. Study Investigator

Every clinical trial will have one or more investigators who run the study. These individuals may be medical professionals, like doctors and nurses, or other types of experts. They put together the study plans, ensure the study operates properly and safely, collect data, and later report on the findings. The main person in charge may be referred to as the principal investigator.⁹

6. Investigational Study Drug

When you’re considering joining a clinical trial, the study investigators might refer to an investigational study drug. This refers to the actual substance being tested during the trial. Although investigational study drugs haven’t been approved by agencies like the FDA, they have been evaluated by an ethics committee to confirm they can be tested on humans.

7. Placebo

Not everyone participating in a clinical trial takes the investigational study drug. Instead, some participants may get a placebo, which is an inactive compound. This allows the investigators to determine if the investigational study drug is working better than the placebo.¹⁰

8. Control Group

To evaluate whether an investigational study drug is working, the study investigators may compare its effectiveness against other therapies. For instance, while one group gets the investigational study drug, the control group may get a placebo or take an existing medication used to treat TED. This allows the researchers to determine whether the drug being tested is more effective or has different side effects than the other option.³

9. Randomization

Trial investigators may determine which participants are given the investigational study drug and which aren’t by using a process called randomization. This allows them to randomly assign (by chance) participants to the treatment group or the control group without manually picking certain people for one group versus the other. Randomly assigning people helps prevent any unfairness.³

10. Single Blind or Double Blind

If study participants don’t know whether they’re part of the control group or the treatment group, it’s known as a single-blind study. When both the study participants and members of the clinical trial staff don’t know which participants are in which group, that’s referred to as a double-blind study. This process may also be referred to as masking. Like randomization, masking helps prevent bias.^1,3

Are you interested in clinical trials for TED? Find out if you’re eligible.