Stem Cell Surgery for Spina Bifida Found Safe in Clinical Trial

A first-in-human clinical trial has demonstrated that combining fetal surgery with stem cell therapy to treat spina bifida is safe for patients. The results of the Phase 1 study indicate that the procedure is feasible, though researchers are still evaluating whether the addition of stem cells improves long-term health outcomes compared to surgery alone.

The findings were published in February 2026 in the medical journal The Lancet. The study, known as the CuRe Trial (Feasibility and Safety of Cellular Therapy for In-Utero Repair of Myelomeningocele), was conducted by a research team at UC Davis Health to determine if adding human placenta-derived stem cells to standard prenatal surgical repairs could protect the developing spinal cord.

Understanding Spina Bifida and Prenatal Intervention

Spina bifida, specifically the form known as myelomeningocele, is a birth defect that occurs when the spinal tissue fails to fuse properly during the early stages of pregnancy. This failure leaves the spinal cord exposed, which can lead to a variety of lifelong challenges, including disabilities related to mobility, cognition, as well as urinary and bowel function.

The current gold-standard treatment for severe cases is fetal surgery, where surgeons close the wound in the womb to prevent further damage. The CuRe Trial sought to supplement this existing surgical approach with a dose of stem cells, a combination that had previously shown success in animal studies.

The Surgical Process and Stem Cell Application

The procedure involves a complex surgical intervention while the fetus is still in the uterus. Surgeons create a small opening in the uterus and float the fetus toward the incision to expose the back and the spina bifida defect.

Once the exposed spinal cord is accessible, the care team places a small patch containing living stem cells directly over the site. These stem cells are derived from donated placentas and are designed to protect the developing spinal cord from further damage before the child is born. After the patch is in place, the surgeons close the layers of the fetus’s back to allow the tissue to regenerate.

Putting stem cells into a growing fetus was a total unknown. We are excited to report great safety

Diana Farmer, principal investigator of the CuRe Trial and chair of the UC Davis Department of Surgery

Farmer noted that these results provide a foundation for future interventions, stating that the trial paves the way for new treatment options for children with birth defects and that the future is exciting for cell and gene therapy before birth.

Funding and Research Scope

The first phase of the clinical trial was supported by a $9 million state grant provided by the California Institute for Regenerative Medicine (CIRM), the state’s stem cell agency.

As a Phase 1 study, the primary objective was to establish the safety and feasibility of the delivery method. Because the trial was designed as a first-in-human, single-arm study, the immediate focus was on whether the cellular therapy could be administered without causing adverse effects to the fetus or the mother.

Future Outlook

While the safety of the procedure has been confirmed, the medical community is now looking toward efficacy data. The goal of the ongoing research is to determine if the stem cell patch provides a meaningful improvement in the children’s outcomes compared to those who receive standard fetal surgery without the cellular supplement.

If the therapy proves effective in improving mobility or neurological function, it could represent a significant shift in how prenatal spinal defects are managed, moving beyond simple closure of the defect toward active regeneration and protection of neural tissue.