A groundbreaking trial has seen a patch made from donor placental stem cells used to treat fetuses in the womb suffering from a severe form of spina bifida. This innovative method appears to have successfully reversed a complex brain condition associated with the congenital disorder, demonstrating effectiveness comparable to the established treatment. Crucially, it holds promise for enabling more children to achieve mobility in the long term.
One mother, whose son Toby is now four years old, shared her initial fears. Diagnosed with the condition while still in utero, she anticipated her son would require a wheelchair. “But Toby is healthy and has met all of his developmental milestones,” she stated. “He is walking, running, and jumping, and has no issues with bladder control, which is unusual for individuals with this condition.”
Understanding Spina Bifida
Spina bifida affects approximately 1 in every 2800 births in the United States annually. It arises when a baby’s spine and spinal cord fail to develop completely within the womb. The most severe iteration, known as myelomeningocele, involves the spinal cord and surrounding tissues protruding through a gap in the vertebrae. This often leads to significant impairments in mobility, as well as bowel and bladder function. While the precise cause remains unknown, a deficiency in folic acid during pregnancy is recognized as a risk factor.
Current and Experimental Treatments
A conventional approach involves surgical intervention during gestation. This procedure aims to reposition the spinal cord and its surrounding tissues back into the vertebral canal, followed by suturing the skin to create a secure seal. However, Diana Farmer, a researcher at the University of California, Davis, noted that “many children still struggle to walk, and there is typically no improvement in bowel or bladder control.”
This limitation prompted Farmer and her colleagues to investigate whether the incorporation of stem cells could enhance the growth and repair of spinal tissue. To explore this possibility, they enrolled six pregnant women whose fetuses had been diagnosed with myelomeningocele.
The Stem Cell Patch Procedure
By approximately 24 weeks of gestation, all the fetuses in the study had developed a common complication known as hindbrain herniation. This condition occurs when excess fluid accumulates in the skull, forcing the lower portion of the brain, the cerebellum, through an opening at the base of the skull. While standard surgery can sometimes alleviate hindbrain herniation, many children continue to experience complications.
In this latest trial, all fetuses underwent the standard surgical procedure. In addition, they received a patch, measuring a few centimeters in length, containing stem cells. These cells were derived from donated placentas and embedded within a matrix of adhesive proteins. Surgeons applied this patch to the spine before closing the skin over it. Farmer described the process, stating, “The cells secrete their magic stem cell juice.”
Post-Natal Outcomes and Future Prospects
Upon birth, the surgical sites in all infants had healed without any indication of abnormal cell growth. “A major concern was that introducing stem cells into a fetus might lead to uncontrolled cell proliferation, but we did not observe that,” Farmer commented. Furthermore, MRI scans of the infants’ brains revealed that the treatment had completely resolved the hindbrain herniation.
Panicos Shangaris from King’s College London offered his perspective: “My personal opinion is that this will lead to better long-term outcomes compared to the standard approach, based on evidence from animal studies.”
The research team plans to further evaluate this method in a trial involving 35 fetuses with myelomeningocele. The outcomes of these infants, who will receive the stem-cell patch, will be compared against data from a previous study that utilized conventional surgery, according to Farmer. Shangaris suggested that a more robust comparison, likely to facilitate treatment approval, would involve a head-to-head trial directly assessing the safety and efficacy of both approaches in fetuses randomly assigned to each intervention.
Journal Reference: The Lancet DOI: 10.1016/S0140-6736(25)02466-3