NurExone Achieves MBP-Positive Cell Signal in ExoPTEN Spinal Cord Preclinical Program

Immunohistochemical tissue data from NurExone Biologic's ExoPTEN program are beginning to sketch a mechanistic picture that will shape the CMC and regulatory strategy long before an IND is filed. The company reported statistically significant increases in Myelin Basic Protein (MBP)-positive cells in ExoPTEN-treated animals two months post-injury, adding biological dimension to functional recovery findings published in July 2025.

The analysis drew on spinal cord tissue collected from animals in that prior efficacy study. Researchers applied immunohistochemical staining across three discrete spinal cord regions: the injury site itself, the rostral zone, and the caudal zone. MBP differences reached statistical significance in both the rostral region (p=0.01) and caudal region (p=0.04). Two additional markers, NeuN and NF200, were assessed for neuronal nuclei and axonal integrity respectively, broadening the mechanistic read without yet producing the same level of significance.

For drug development and regulatory leads tracking the exosome-based biologics space, the data carry a forward-looking manufacturing implication. Exosome-loaded therapeutic platforms present distinct CMC challenges: characterisation of cargo loading efficiency, batch-to-batch consistency of the exosome vector, and demonstration of potency assay correlation with a defined biological endpoint. MBP preservation now offers a candidate surrogate marker that could anchor a potency assay strategy, though that work remains ahead of the program at this stage.

NurExone describes ExoPTEN as an exosome-based regenerative therapy delivered intranasally, a route that carries its own formulation and sterility assurance considerations under 21 CFR Part 211 and relevant ICH quality guidelines. The intranasal delivery format sidesteps some parenteral sterility demands but introduces mucosal absorption variability that process development teams will need to address as the program moves toward GLP toxicology and eventual clinical-stage manufacturing.

Dr. Tali Kizhner, Director of Research and Development at NurExone, noted that the MBP findings may help explain how ExoPTEN supports neural tissue preservation following injury, framing the results as mechanistic evidence rather than efficacy confirmation. The company positions the data as contributing to the scientific and regulatory foundation for the program's advancement through preclinical development.

The next measurable checkpoint for the ExoPTEN program is completion of the broader preclinical package sufficient to support regulatory submission for first-in-human studies, with MBP-positive cell counts now part of the evidentiary record.

Source: NurExone Biologic Inc. via GlobeNewswire, 14 August 2026.