What Is Biliary Atresia?

Biliary atresia (BA) is a rare liver disease starting in infancy. It involves a blockage in the tubes (ducts) that carry bile from the liver to the intestines. This blockage can lead to liver damage and loss of liver function.

Common Symptoms of Biliary Atresia May Include:

Yellowing of skin and/or eyes (jaundice)

Swollen abdomen

Pale stools and dark urine

Slow weight gain

How is Biliary Atresia Treated?

Children with biliary atresia typically have surgery soon after diagnosis. The Kasai procedure (also known as hepatoportoenterostomy or HPE) is an operation to help bile drain from the liver. The Kasai procedure is not a cure for biliary atresia and there are currently no medications approved for the treatment of biliary atresia. Over time, bile can still build up in the liver and cause damage. Unfortunately, about half of children will require a liver transplant by the age of 2 years despite Kasai surgery.

About the Study


We understand this is a difficult time for you and your family. Our mission is to help you understand this study and its purpose.

The goal of the EMBARK study is to see if the study medicine, maralixibat, can improve the liver health of children with biliary atresia.

For the first 6 months, this will be a placebo-controlled study, meaning half of the children will be randomly assigned to receive the study medicine (maralixibat) and the other half will receive a look-alike solution (placebo) with no active medicine. Neither you nor the study staff will know if your child is receiving maralixibat or placebo. Using placebo is often required in clinical studies to scientifically compare and prove that the study medicine works. In the event of a medical emergency, your study doctor will be able to find out which group your child belongs to.

After the first 6 months of the study, all children will enter the long-term extension phase of the study. In this part of the study, all children, including those originally assigned to receive the placebo, will be given maralixibat. The long-term extension phase of the study will last for approximately 1.5 years.

What to Expect

Your child must have undergone the Kasai procedure (HPE) within 3 weeks of starting EMBARK. In this time, your child’s eligibility to participate in the study will be reviewed in what is called the screening period.

If your child fulfils all screening criteria, there will be an in-person clinic visit in which your child will be randomly assigned to receive either maralixibat or placebo.

In the first weeks of the study, doses of study medicine will be gradually increased until the target or best-tolerated dose is reached. In the first 6 months of the study there will be 7-9 clinic visits.

After the first 6 months, all children will receive maralixibat. During this time, you will need to come to the study clinic just once every 4 weeks. This will be further reduced to once every 4 months after the first year.

During a normal visit to the study clinic, the following may occur:

  • Questions to check how your child is doing
  • Physical examination (e.g. blood pressure, heart rate, body temperature)
  • Blood sample collection to check the health of your child
  • Checks to ensure the medicine is being given correctly

Click below to learn more about
the EMBARK study.

Your Child May Qualify To Participate In The EMBARK Study If They:

  • Have been recently diagnosed with biliary atresia
  • Are younger than 90 days at the time of the Kasai procedure
  • Can start the study within 3 weeks of the Kasai procedure
  • Do not urgently need a liver transplant

There are some additional requirements to participate. A study representative will discuss them with you.

Frequently Asked Questions

What is a clinical research study?

A clinical research study tests the safety and effectiveness of an investigational medicine in children or adults who agree to participate. Every medicine goes through the clinical research process before it is approved by regulators who then allow doctors to prescribe it outside of a research study. Study participants therefore play a very important role in advancing medicine for both present and future generations.

What is an investigational medicine?

An investigational medicine has not been approved by the US Food and Drug Administration (FDA) or other health authorities but has permission to be given to study participants for clinical research.

What is maralixibat?

Maralixibat is a grape-flavoured liquid taken by mouth. It is an investigational medicine being studied in several rare liver diseases, including biliary atresia. Over 1,600 people have received maralixibat, including more than 120 children with liver disease. Maralixibat has been studied in children with other conditions where bile does not drain effectively from the liver, such as Alagille syndrome (ALGS) and Progressive Familial Intrahepatic Cholestasis (PFIC). Maralixibat has been approved by the U.S. Food and Drug Administration (FDA) to treat cholestatic pruritus (itch) in patients aged 1 and older with Alagille syndrome.

How does maralixibat work?

Maralixibat reduces the level of bile acids circulating in the body by helping remove them during digestion. This results in more bile acids being in the feces (poop), a normal route for bile acids to leave the body and lower levels of bile acids circulating in the body.

What is a placebo?

A placebo is similar in appearance to the study medicine but does not contain any active ingredients. In this study, all packaged study medicine components will be identical to avoid participants or study doctors knowing what each participant is receiving. The study analysis will compare the safety and effectiveness between maralixibat and placebo.

How do I give the study medicine to my child?

The study team will give the first dose of the study medicine to your child. They will also show you how to do this at home and give you instructions to take with you. The amount of medicine your child will need depends on how much your child weighs. Your study doctor will tell you how much this should be at each visit, but the volume will be less than 1ml (1/4 teaspoon) of liquid per dose. The study medicine should be given once in the morning and once in the evening. You will get dosing dispensers to squirt the study medicine into your child’s mouth.

How long is the EMBARK study?

The study will last approximately two years. For the first 6 months, half of the children will be randomly chosen to receive maralixibat, while the other half will receive a near identical liquid without the medicine in it (placebo). After the first 6 months, all children, including those originally assigned to receive the placebo, will be given maralixibat. This means that all children involved in this study will have the opportunity to receive maralixibat.

What are the risks to my child?

There is a chance that your child may experience the side effects associated with the study medicine.


Maralixibat has been studied in more than 1600 people already, including over 120 children. In previous studies, maralixibat was generally well tolerated with the most common side effects being loose stools (diarrhoea) and stomach pain. These symptoms were generally of mild or moderate intensity, were short in duration, and resolved on their own.

What are my responsibilities while my child is participating in this study?

Participation in clinical research studies is voluntary and you do not have to join this study. If you decide to not take part in this research, your care will not be affected. If you do decide to take part in this research, then you can withdraw your consent at any time without penalty. During the study you will be asked to follow the instructions in the Informed Consent Form. If you are unable to follow these, your child may not continue the study.


To help protect your child’s health, the study will be supervised by a study doctor and their trained team. You may need to share information on your child’s current and past health during the screening period and at clinic visits.


You will be asked to complete a dosing diary, making note of what time and how much of the study medicine has been given to your child. We also ask a series of other questions such as whether you had to take any time off work because of your child’s biliary atresia. This helps us understand the full impact of the condition not only for the patients, but for their families as well.


If you have a family doctor, it is strongly recommended that you inform them of your interest in this study.

Is there any cost for participating in this study?

There is no cost to you and your family to participate in this study. Participants will receive reimbursement for any reasonable out-of-pocket costs associated with being part of the EMBARK study, such as travel, parking and meals. We can also arrange for someone to book and pay for rail and flight tickets if you don’t live close to the study clinic. Certain limitations apply.

What happens when the study ends?

At the end of the EMBARK study, your study doctor will talk to you about your child’s future care. For those families who want to continue maralixibat treatment, Mirum will help ensure that opportunities to access this medicine continue to be available as appropriate.

How can I learn more about the investigational medicine and this study?

More information on the EMBARK clinical study can be found at: https://clinicaltrials.gov/ct2/show/NCT04524390?term=NCT04524390&draw=2&rank=1