Intranasal Stem Cell Therapy Shows Promise for Newborn Brain Injury in PASSIoN Safety Trial
Key Insights
A safety study at UMC Utrecht demonstrated that intranasal mesenchymal stem cell therapy administered within a week of birth showed no side effects in ten newborns with perinatal stroke (search) over two years of follow-up.
Only 20% of treated infants developed mild cerebral palsy (search) compared to 50% in historical controls, despite all children initially showing motor pathway damage that typically carries over 80% cerebral palsy risk.
The PASSIoN trial results, published in Stroke journal, will inform the upcoming iSTOP-CP efficacy study launching in 2026 with 162 newborns to definitively test the treatment's effectiveness.
A novel intranasal stem cell therapy has demonstrated promising safety results in newborns with perinatal stroke (search), offering new hope for preventing long-term neurological complications including cerebral palsy (search). The PASSIoN safety study, conducted at UMC Utrecht and published in Stroke journal, followed ten infants who received mesenchymal stem cells (search) via nasal drops within a week of birth.
Safety Profile and Clinical Outcomes
Two years after treatment, none of the children experienced therapy-related side effects. While there were two hospital admissions during the follow-up period, researchers confirmed these were unrelated to the stem cell therapy. Notably, none of the children required ongoing medication after hospital discharge.
The developmental outcomes exceeded expectations for this high-risk population. Most children showed remarkably positive development, starting to walk earlier on average than untreated children with comparable brain damage. One child experienced mild cognitive delay, two had language delays, and one suffered from severe sleep problems, but the overall developmental trajectory was encouraging.
Reduced Cerebral Palsy Incidence
The most striking finding involved motor development outcomes. Only two children (20%) developed mild cerebral palsy (search), a dramatic reduction compared to 50% in historical control groups with similar stroke types. Scientific literature reports cerebral palsy rates of up to 70% in comparable populations.
This outcome is particularly significant given that all children in the study initially showed damage to the brain's motor pathways (search). Such damage typically carries a cerebral palsy (search) risk exceeding 80%, depending on the infarct's size and location. Additionally, none of the treated children developed epilepsy (search) or vision problems.
"Seeing such positive development in a high-risk group like this is truly extraordinary," said pediatrician and professor Manon Benders. "It gives not only the parents but also us as a medical team real hope."
Treatment Protocol and Mechanism
The therapy involved a single dose of mesenchymal stem cells (search) administered as nasal drops within seven days of birth. All ten babies in the study had experienced perinatal stroke (search), a type of brain injury (search) occurring just before, during, or shortly after birth that damages the developing brain and can lead to long-term neurological problems.
The amount of brain tissue loss observed was smaller than expected given the severity of the strokes, suggesting potential neuroprotective effects of the treatment.
Path to Efficacy Testing
Researchers emphasize that the PASSIoN study was designed specifically to assess safety rather than prove effectiveness. To definitively determine the therapy's efficacy, the iSTOP-CP study is expected to launch in early 2026.
"We've spent years conducting fundamental research in the lab, where we saw that stem cells have enormous potential for brain repair," said neuroscientist and professor Cora Nijboer. "These results, in such vulnerable babies, are exactly what we've been working toward."
Upcoming Efficacy Trial
The iSTOP-CP study will enroll 162 newborns with brain damage due to stroke or severe oxygen deprivation. Within seven days of birth, participants will receive either stem cells or placebo, with researchers monitoring development until 24 months of age. If proven effective, the therapy could significantly transform treatment approaches for newborn brain injury (search).
Health economist Renske ten Ham will conduct a cost-effectiveness analysis during the study, evaluating how the treatment's costs and benefits compare to current care standards, including impacts on child development and parental burden.
The study has garnered broad international support from patient organizations including CP Nederland (search), Care4Neo, the Cerebral Palsy Foundation (search) in the US, Cerebral Palsy (search) Alliance in Australia, and Fondation Paralysie Cérébrale in France. All neonatal intensive care units in the Neonatology Network Netherlands are participating due to the condition's rarity requiring collaborative efforts.