
Participating in a clinical trials helps develop treatments for Fontan patients today - and for the next generation.
Fontan teens deserve options.
Your participation can make a difference.
The FUEL-2 study is evaluating udenafil as a treatment to potentially increase energy levels and improve exercise capacity in Fontan patients.
Exercise capacity will be tested at the start and end of the six-month trial, with participants taking daily medication.
All travel-related expenses will be covered; participants may receive additional compensation.
Fontan teens ages 12 to 18 may be eligible to participate.
Check out our videos:

Join the FUEL-2 Trial at a Site Near You!
Qualified participants may receive compensation and have all travel expenses, including airfare, lodging, and gas, covered.
Get started — See if your Fontan teen (ages 12-18) may be eligible
Submit your information in the form below to be contacted by a study team member to see if you may be eligible to participate. The information you provide will be kept confidential.
After filling out the interest form, one of our dedicated recruitment coordinators will contact you to discuss your potential eligibility for the FUEL-2 clinical trial. Our coordinators are here to help determine if this study is the right fit for you and connect you with a study site that is most convenient for you.
Meet the Recruitment Coordinators
Thomas Giorgio
Boston Children’s Hospital
Claire Wei
Boston Children’s Hospital
Rahul Rathod, MD
Boston Children’s Hospital
FUEL-2 Global Principal Investigator

FAQs
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Before new medicines can be used to treat people, doctors must make sure that the medicines work and are safe. To do this, they test the new medicines in clinical research studies, with the help of other doctors and scientists.
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This is a study to test a new medicine for teenagers with a heart condition called single ventricle heart disease.
The study doctors are looking at a possible new medicine, called udenafil. This medicine could help children and teenagers who had the Fontan procedure have more energy.
Udenafil works by relaxing the blood vessels and improving blood flow to the lungs. This way your blood oxygen levels are higher, and you may be less tired when exercising or during everyday activities.
In this study, we want to find out how well udenafil works to improve your ability to exercise and do your daily activities. We also want to know how safe udenafil is for teenagers with single ventricle heart disease. who had the Fontan procedure.
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Single ventricle heart disease is a medical condition that some babies are born with. A heart usually has 4 chambers: 2 atria and 2 ventricles. In single ventricle heart disease., the heart has only 1 ventricle. The ventricles are the main pump for the heart. They send blood out to the lungs and the rest of the body.
Most people with single ventricle heart disease need to have multiple surgeries when they are babies to help their heart work better. One of those surgeries is called the Fontan procedure. It is done to direct the blood to the lungs instead of the heart.
Even after the Fontan procedure, the heart must work harder to pump enough blood and oxygen around the body. This can make it harder for children and teenagers with SVHD to do physical activities that require a lot of effort, like playing intense sports or doing challenging exercises. For this reason, you may also need to take medicines to help improve your blood flow.
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There are different medicines to help improve your blood flow. However, some of these medicines cannot be given to teenagers or do not work the same for everyone.
This is why it is important to research new medicine options for teenagers who had the Fontan procedure.
We hope that what we learn in this study may help doctors treat other teenagers with single ventricle heart disease. who had the Fontan procedure in the future.
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You will not be alone! More than 400 teenagers with single ventricle heart disease who had the Fontan procedure, just like you, will be invited to take part in this study.
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In this study, you will be placed by chance (like flipping a coin) in 1 of 2 groups. Depending on which group you are placed in, you will receive:
udenafil (the study medicine), twice a day
a placebo, twice a day
The placebo is a “dummy medicine.” This means that it looks just like the study medicine but contains no active medicine. Both udenafil and the placebo can be called the “study medicine” from here on. You, your parents (or the person looking after you), and the study doctor will not know which study medicine you will receive. You will have the same chance of receiving either udenafil or the placebo.