A Phase II Randomized Study of the Safety of Apixaban versus Vitamin K Antagonist or LMWH in Pediatric Subjects with Congenital or Acquired Heart Disease
Apixaban Study Basics
People with certain types of heart disease may need to take medication to prevent their blood from clotting. That medication is called an anticoagulant or a blood thinner. The purpose of this study is to find out whether the medicine called Apixaban (commonly known as Eliquis®) is safe for children with heart disease, and to learn how much Apixaban will be present in the blood after taking a certain dose. Researchers will compare Apixaban to two other widely used blood thinners in children with congenital or acquired heart disease. Approximately 150 children will be enrolled over 36 months across 11 Pediatric Heart Network Centers and several centers in other countries.
Who can be in the study?
Children between birth and 17 years old with congenital or acquired heart disease who need to take chronic medication to prevent blood clots are eligible for the study. Females cannot be pregnant and must not be actively breastfeeding. Patients can either be just starting anticoagulants for the first time or be on long-term medications like Vitamin K Antagonists (VKA) [Warfarin, Coumadin] or Low Molecular Weight Heparin (LMWH) [Enoxaparin, Lovenox, Xaparin] for at least 6 months after a blood clot was found. Children with prosthetic and mechanical heart valves are not eligible to be in the study.
What do we have to do to be in the study?
The study will be explained to you in detail by one of the study investigators. Once your questions have been answered, you will be asked to sign an informed consent form to enter the study. The study has four major parts:
- Screening: We will collect information about your child’s medical history and do a physical examination, which includes measuring heart rate, blood pressure, body temperature, height and weight; and draw blood for laboratory tests. Children 5 years and older will have a bone density scan. Females of child bearing potential will also be asked to provide a pregnancy test.
- Randomization: Your child will be randomly assigned to receive either Apixaban (by mouth or tube) or to receive one of the blood thinners commonly used to treat his or her condition: either VKA or LMWH. The study doctor will give you instructions about your child’s particular study medication. Your child will also be asked to answer survey questions about quality of life, and provide a blood sample.
- Treatment: Your child will take the study medication for 12 months, or until they no longer need a blood thinner, whichever is shorter. We will ask you to keep track of the medication taken by your child every day in a diary that the study team will give you. We will ask you and your child to visit the study center at 2 weeks, 3 months, 6 months, 12 months and 14 months. At each visit, we will do a physical examination of your child and draw blood for laboratory tests. These visits will also include questions about side effects, adverse events, and whether your child has developed a blood clot or bleeding. Some of these visits will also include a bone density scan and quality of life questionnaires. The study center will also call you to see how your child is doing at 8 months and 10 months.
- Follow-up: Your child will have one final study visit, either in person or over the phone, after they finish taking the study medication. This will be at about 14 months, or two months after your child finishes taking the study medication, if he or she takes it for less than 12 months. We will ask you again if your child has had any illnesses, bleeding, or clots, or if he or she has been hospitalized.
How long will we be in the study?
If your child qualifies for this study, his or her participation can last for up to 14 months, or until anticoagulation is no longer needed – whichever is shorter.
What are the possible benefits to being in this study?
- Apixaban may prevent formation of dangerous blood clots or prevent the growth of existing blood clots.
- Your child may not benefit from taking part in this research study. But the information we learn from this study may help improve the care of other children.
What are the possible risks to being in this study?
- Taking part in a research study involves risks or “side effects.” You should talk about these risks with the study doctor or your child’s regular doctor. There may be other side effects we do not know about yet. We may give your child other medicines to make any side effects less serious or to make your child feel better.
- As with any anticoagulant medication, there is an increased risk of bleeding. Your child might have a minor bleed (nosebleed, bleeding gums or bruising). In rare occasions, bleeding may occur in critical organs of the body, such as in the brain and stomach or may be related to surgery or a medical procedure. This bleeding can be dangerous, permanently disabling, or fatal. Other possible side effects observed in people in previous studies of blood thinners include dizziness, rash, itchiness, and headache.
- Your child might have a black and blue mark or a small amount of bleeding where the needle is put in his or her body for the blood test. There is a very small chance that this area will get infected. Your child might feel lightheaded or dizzy or even faint after the blood test.
- A bone scan is a simple, quick and noninvasive procedure. The amount of radiation used during this scan is extremely small, less than 10% of the radiation received in a standard chest x-ray.
- There may be risks to being in this study that we don't know about now. You will be informed of any changes in the way the study will be done and any additional risks identified.
What are the costs to me to be in the study?
There will be no extra costs to you when you join this study. You must pay for all other costs related to your normal medical care such as hospital stays, surgery, drugs, lab tests, and doctor's fees which are thought to be standard medical care for patients with your condition.