New Phase II Clinical Trial Now Open

Jun 25, 2019 | Brianna N. Tranby | @briannatranby

shutterstock_127510118 (1)

The Todd and Karen Wanek Family Program for Hypoplastic Left Heart Syndrome (HLHS) at Mayo Clinic is excited to announce a new Phase II clinical trial for infants diagnosed with HLHS before birth. This clinical trial uses stem cells collected from the baby’s own umbilical cord blood (UCB) at birth and delivers them into the heart to help strengthen the heart muscle. There are two parts to this study: a Treatment Arm and a Control Arm.

Treatment Arm

Babies with HLHS standardly undergo a Stage I (Norwood) surgery shortly after birth, followed by a Stage II surgery (Glenn) a few months later. In this study, a baby’s own stem cells from the UCB are injected into the right side of the heart during the Glenn surgery. The stem cells release growth factors that act like fertilizer to help the heart muscle grow bigger and stronger.

A Phase I study was completed in 2018 and showed that the procedure is safe. This Phase II study will help researchers determine if the procedure helps the heart muscle recover after surgery and get stronger in the future.

To participate in the Treatment Arm and be eligible to receive the stem cell delivery, a baby’s UCB must be stored with the Todd and Karen Wanek Family Program for HLHS at birth. There is no cost to collect and store UCB with the program. For more information on UCB banking options, you can read our earlier blog post.

Control Arm

This trial is also open to infants with HLHS who did not have UCB collected. This might happen if a baby was not diagnosed before birth or the collection attempt was not successful. Infants with HLHS can still participate in this groundbreaking clinical trial by enrolling in the Control Arm before the Glenn surgery.

Infants on the Control Arm will not have stem cells delivered during surgery. However, their medical data will provide important information to compare and understand how babies’ hearts are affected by surgery with and without the stem cell delivery. Babies on both arms of this study will also undergo an additional MRI scan after surgery to get an in-depth look at how the heart is functioning. The cost of the MRI will be covered by the study.


Trial Open at HLHS Consortium Sites

The HLHS Consortium was created to bring innovative research opportunities to more patients across the country. UCB can be collected at birth from any hospital and stored with the Program. However, the stem cell delivery and Glenn surgery must be performed at one of the following hospitals in the HLHS Consortium: Children's Minnesota (Minneapolis, MN), Children's Hospital of Philadelphia (Philadelphia, PA), Children's Hospital of Los Angeles (Los Angeles, CA), Children's Hospital Colorado (Aurora, CO), or The Children's Hospital at OU Medicine.

“We’re excited to join forces with the physicians and research teams at these sites,” says Tim Nelson, MD, PhD, director of the HLHS Program at Mayo Clinic. “It means that individuals with HLHS will now have more access to participate in groundbreaking clinical trials.”

To learn more about this study, contact or visit our website.


The Todd and Karen Wanek Family Program for Hypoplastic Left Heart Syndrome (HLHS) is a collaborative network of specialists bonded by the vision of finding solutions for individuals affected by congenital heart defects including HLHS. The specialized team is addressing the various aspects of these defects by using research and clinical strategies ranging from basic science to diagnostic imaging to regenerative therapies. Email the program at to learn more.

Interested in more newsfeed posts like this? Go to the HLHS blog.

Please sign in or register to post a reply.