A checklist of important questions to ask before enrolling in a clinical trial.
Write these down. Bring them to your screening appointment or call the coordinator. Take notes on the answers.
1. What phase is this trial?
2. Is there a placebo arm? If so, how are participants assigned to groups?
3. What happens if I get the placebo? Is there an open-label extension where I can access the real drug afterward?
4. How often do I need to visit the trial site?
5. How long does the trial last?
6. What tests and procedures will I need?
7. What are the known side effects?
8. If I have a serious side effect, how will that be handled?
9. Can I continue my current medications while in the trial?
10. What happens after the trial ends? Will I have access to the drug if it works?
11. What costs will the trial sponsor cover? What will my insurance be billed for?
12. Will the trial reimburse travel, parking, or meals?
13. Who can I call if I have questions or concerns during the trial?
14. Can I leave the trial anytime?
15. How will my data be used? Who can see it?
Gene therapies (like AAV vector delivery) and cell therapies (like CRISPR-edited cells in Casgevy) are typically one-time treatments with potentially permanent effects. The risk-benefit calculation differs from a daily pill that you can stop. Ask the additional questions below if you are considering a gene or cell therapy trial.
1. Is this treatment intended to be one-time, or will I need repeat dosing?
2. If something goes wrong, can the treatment be reversed or removed from my body?
3. What is the long-term follow-up requirement? FDA typically requires 15 years of monitoring for gene therapies.
4. What pre-treatment conditioning will I need? For some cell therapies, this includes chemotherapy that affects fertility.
5. Will I need to bank sperm or eggs before conditioning? Is fertility preservation covered?
6. What are the known risks of the viral vector or gene-editing approach being used? (For example, AAV vectors carry liver toxicity risk; lentiviral vectors carry insertional mutagenesis risk.)
7. Will pre-existing antibodies to the vector exclude me from this trial or future gene therapies?
8. If the therapy works, will I still be able to receive other gene therapies in the future for the same or different conditions?
9. What is the manufacturing timeline? Some autologous cell therapies take 4 to 12 weeks to produce.
10. What happens if my cells fail manufacturing or if the dose doesn't engraft?
Enrolling a child in a clinical trial carries different considerations than enrolling yourself. Children cannot legally consent, so parents or legal guardians provide permission while the child provides assent (typically age 7 and up). The questions below help caregivers evaluate pediatric trials specifically.
1. Has this drug been studied in adults first? If so, what were the safety findings?
2. What is the youngest age that has received this drug? My child is younger than that, what does that mean for risk?
3. How will the drug be dosed for my child's weight and developmental stage?
4. How will my child be assessed for assent? What if my child doesn't want to participate but I want them to?
5. What support is available for needle phobia, IV placement, or distressing procedures?
6. Are siblings or other family members allowed at visits? Is there child-life specialist support?
7. Will my child miss school? Is there a tutor or virtual schooling option for inpatient stays?
8. What developmental assessments are part of the protocol? Will I get those results?
9. How does this trial accommodate non-verbal children or children with cognitive differences?
10. If we travel to a trial site, are accommodations available for the whole family? What does the sponsor cover?
Many participants assume that if a trial drug works for them, they will continue receiving it after the study ends. That is not always the case. Post-trial access depends on the sponsor's policies, regulatory pathways, and whether the drug ultimately receives approval. Ask the questions below before you enroll, not after.
1. Is there an open-label extension (OLE) study after the main trial? If so, do all participants qualify?
2. If the drug is not yet approved when my OLE ends, can I get it through expanded access (compassionate use)?
3. If the drug receives FDA accelerated approval, will I be able to fill it through commercial insurance, or will I need patient assistance?
4. If the trial fails or the sponsor abandons development, what happens to participants who responded to the drug?
5. Does the sponsor have a written post-trial access policy? Can I see it in writing?
6. If I move to another country during the trial, will my access transfer?
7. What are my options under federal Right to Try law if expanded access is denied?
8. If I experience a serious adverse event, is the sponsor obligated to cover related medical care after I leave the trial?
Trial drugs are investigational, which means the full safety profile is still being characterized. The questions below focus on how the trial team will detect, manage, and report side effects, as well as your rights as a participant if something goes wrong.
1. What are the most common side effects reported in earlier phase trials?
2. What serious adverse events (SAEs) have occurred in this drug program?
3. Have any participants died during this drug's clinical development? What was the cause?
4. What is the protocol for stopping the drug if I have a serious side effect? Will I be tapered or stopped immediately?
5. If I am hospitalized due to a side effect, who pays the hospital bill, the sponsor or my insurance?
6. Is there a Data Safety Monitoring Board (DSMB) reviewing this trial? How often do they meet?
7. If a safety signal emerges in another participant or trial site, will I be notified?
8. Where can I report a side effect that the trial team does not seem to be acting on? (FDA MedWatch is one option.)
9. If I am injured by the trial drug, does the sponsor have liability insurance? Will I receive compensation?
10. What is the policy on revealing my treatment assignment if I have a medical emergency that requires it?
There is no rush to decide. Yes, enrollment windows can close. The research team would rather have thoughtful participants than people who enroll and then regret it. Ask all the questions. Get answers in writing. Read the informed consent carefully. Talk to your family, your doctors, your advocate organization.
If the site coordinator seems impatient or unwilling to answer your questions thoroughly, that is a red flag. You have the right to understand what you are agreeing to. Federal regulations (45 CFR 46) require that informed consent be given without coercion and that you have adequate time to consider your options.
Before joining a clinical trial, ask about the trial phase, whether there is a placebo arm, how long the trial lasts, what tests and procedures are required, the known side effects, what costs the sponsor covers, whether travel is reimbursed, and what happens if the drug works for you after the trial ends. The 15 essential questions earlier on this page cover the core list.
Yes. Federal regulations require that you have adequate time and opportunity to ask questions before signing informed consent. You can take the consent form home, discuss it with your physician or family, and return with questions. A trial site that pressures you to sign immediately is not following Good Clinical Practice (GCP) standards.
The most important question for gene therapy trials is whether participation will exclude you from receiving other gene therapies in the future. Pre-existing or developed antibodies to AAV vectors can permanently exclude you from related therapies. Ask about long-term follow-up requirements (FDA mandates 15 years for gene therapies) and what reversal options exist if something goes wrong.
Parents should ask whether the drug has been studied in adults or older children first, the youngest age previously dosed, how dosing is calculated for their child's weight and developmental stage, what assent procedures will be used, whether child-life specialists are available, school accommodation policies, and what family travel and lodging are covered. Pediatric trials must include both parental permission and child assent for participants old enough to provide it (typically age 7 and up).
If you receive placebo, you will continue to receive standard of care for your condition, and many trials offer an open-label extension (OLE) where placebo participants can switch to the active drug after the blinded portion ends. Ask whether an OLE is part of this protocol, when it begins, and whether all participants qualify or only those who completed the main study.
Ask about the most common side effects from earlier phase trials, what serious adverse events have occurred in the drug's development program, the protocol for stopping the drug if you have a reaction, who pays for hospitalization caused by a trial-related side effect, and whether the sponsor carries liability insurance for trial-related injuries. Federal regulations require that the consent form disclose foreseeable risks.
Yes. Participation in a clinical trial is voluntary, and you can withdraw at any time without penalty and without losing access to standard medical care. The informed consent form must explicitly state your right to withdraw. If withdrawal involves a tapering schedule for safety reasons, that should be discussed in advance, but you cannot be forced to continue.
The informed consent form will list a primary trial contact (usually the principal investigator or study coordinator) along with a 24/7 emergency number. It will also list the Institutional Review Board (IRB) contact, which you can use if you have concerns about how the trial is being conducted that you do not feel comfortable raising with the trial team directly.