First-in-Human Success for Prenatal Stem Cell Therapy in Spina Bifida

For the first time ever, a stem cell therapy has been used to treat spina bifida in a fetus during pregnancy. Results from a Phase I clinical trial, published today in The Lancet, reveal that the treatment is safe and shows early signs of improving mobility and overall health after birth in six children with spina bifida treated using this novel approach.  

“By intervening at early stages of development, this approach has the potential to alter lifelong health trajectories, reducing the burden of chronic disability and minimizing the long-term social and economic impact of these conditions,” write the authors of the study, led by Aijun Wang, PhD, professor of surgery and biomedical engineering at the University of California, Davis. “Currently, no regenerative stem cell products are commercially available to treat diseases in utero. (…) This trial establishes a scalable and clinically feasible platform for the targeted delivery of biological therapeutics to the fetus.”

Spina bifida is a congenital condition that affects the development of the spinal cord, leaving part of it exposed during fetal development. This results in cerebrospinal fluid leaking out as well as damage to the spinal cord before birth, causing lifelong disability including paralysis, difficulty walking, and problems controlling bladder and bowel functions. 

Currently, the condition can be treated with surgery during the second trimester of pregnancy, repairing the exposed spinal cord to prevent further damage to it. This surgery can prevent the development of some brain abnormalities and improve mobility, but more than half of all operated children still cannot walk independently later on. 

By adding stem cell therapy to this surgical procedure, Wang and colleagues aimed to not just prevent further injury, but to also reverse some of the damage already caused by spina bifida at the time of surgery. The treatment makes use of placenta-derived mesenchymal stem cells (PMSCs), which were obtained from donated placentas collected from patients at UC Davis who gave their consent.

The Cellular Therapy for In Utero Repair of Myelomeningocele (CuRe) clinical trial recruited six women who had fetuses diagnosed with myelomeningocele—the most severe form of spina bifida—who were treated at UC Davis School of Medicine. During fetal surgery, live PMSCs were applied directly on the exposed spinal cord to reduce inflammation, promote healing, and protect the nerve tissue.  

All six babies had intact spinal repairs after birth, showing no signs of infection or abnormal tissue growth. Magnetic resonance imaging (MRI) scans confirmed that brain abnormalities typical of spina bifida were reversed in every child, and no serious side effects were reported during the trial or follow-up care. All six children in the trial will continue to undergo regular check-ups until age six to monitor the long-term safety of the treatment.

After a decade of preclinical development, including successfully treating spina bifida in sheep, this trial marks the first time a stem cell therapy is used to treat this condition during pregnancy. The primary goal of the Phase I CuRe trial was to confirm the safety of this approach. An ongoing Phase I/IIa trial is already underway to evaluate the long-term safety and efficacy of the stem cell treatment.