A Phase I clinical trial evidences potential of regenerative therapy for hypoplastic left heart syndrome (HLHS) through collecting, processing, and injecting an infant’s own stem cells directly into the heart at the time of surgery.
Published in The Journal of Thoracic and Cardiovascular Surgery, the Mayo Clinic study focused on the safety and feasibility of stem cell treatments designed to strengthen the heart muscle of children with hypoplastic left heart syndrome, a severe congenital heart disease, reports Technology Networks.
Hypoplastic Left Heart Syndrome (HLHS)
Afflicting 1,000 infants per year in the United States, babies are born with the left side of the heart critically underdeveloped. This condition requires a surgical intervention to support the remaining function in the right side of the heart. Typically, infant patients face a three staged reconstructive surgery process. Known as the Norwood surgery, this will be performed within the first days of life. Second, the Glenn surgery occurs within a few months of age. Finally, the Fontan operation is performed at 2 to 4 years after birth.
The HLHS Consortium: A Special Investigative Network Forms
No single hospital can treat enough of these patients to advance the research with the scope, scale and pace provided by Mayo Clinic’s HLHS Consortium, reports Tim Nelson, MD, PhD, and senior author and director of the Todd and Karen Wanek Family Program for Hypoplastic Left Heart Syndrome.
Seven hospitals and an advocacy group have joined Mayo Clinic to provide HLHS patients across the U.S. care with a combined effort of investigative teams sharing optimal care options and information for patients, families, and research representing a growing support network.
During the Phase I clinical trial, the team studied 10 babies diagnosed with KLHS prior to birth. Each of the babies were enrolled in the ongoing Mayo Clinic Umbilical Cord Blood Collection Study. A minimum of 35 milliliters of cord blood was collected at the time of birth—the investigative team utilized a specialized collection kit. Mayo Clinic processed and provided storage; Mayo’s Therapy Laboratory and ReGen Theranostics inc. manufactured a highly concentrated specialized stem cell product that could be stored and then shipped back to the hospital to be directly thawed and injected into the heart muscle at the time of the baby’s second surgery.
The patients went through the first surgery; thereafter, each baby received processed stem cells during the second operation.
This was the first study to use a cell-based therapy by direct injection during heart surgery in children. Thereafter, the team secured three months of follow-up data from the first child prior to administering the injection to the second child, and the same processes for the third.
All 10 patients completed the second surgery with stem cell injections directly into the heart. No deaths occurred. None of the children had any material safety. Investigator Nelson believes that after this study “the infrastructure is now in place to collect and process stem cells with this method for any HLHS baby born in the U.S.”
Harold Burkart, MD, a pediatric cardiothoracic surgeon at OU Medicine in Oklahoma stated, “We now have a reproducible protocol to utilize stem cell therapy in babies with HLHS. Our hopes are that this groundbreaking research will lead to stem cell therapy strengthening these babies’ hearts while delaying or even preventing the need for a heart transplant in some.”
HLHS Consortium Expands Clinical Trials
The HLHS Consortium is now conducting a Phase IIb study with 50 infants. With a focus on testing the ability of stem cells to improve heart function, the investigators are also enrolling control patients who do not receive cell delivery because HLHS was not diagnosed before birth or cord blood was not controlled.
Tim Nelson, MD, PhD, director of the Todd and Karen Wanek Family Program for Hypoplastic Left Heart Syndrome
Harold Burkart, MD, a pediatric cardiothoracic surgeon at OU Medicine in Oklahoma