A collaboration between Karolinska Institutet and the Oxford-based company Evox Therapeutics has brought gene editing in the living brain a significant step closer to the clinic.
They asked: can we get a gene editor system called CRISPR into the brain, to the right cells, at high enough efficiency, using a deliverable and scalable platform?
The research groups engineered CRISPR and its vesicular delivery system (fat bubbles that cells can absorb) so that more of the gene editing complex ends up inside. These are then delivered to the affected cells, which can absorb their gene editing content. Their particular modifications increase the potency of this method by approximately 300-fold.
Once this was tested in live animals, the results were striking. Healthy primates and rodents were used to examine gene-editing efficiency relevant to Huntington’s disease, a genetic disorder with age-related acceleration of pathology. The animals used, however, were not models for the disease itself; the study targeted the MSH3 gene, which is known to be involved in disease progression.
Local injections into the striatum later revealed 20-60% editing in mice and 60-75% in some regions of the primate striatum. Human brain organoids showed approximately 45% editing, and in human neurons the same system effectively shut down production of the ataxin-2 protein, a target for ALS. In addition to these results, the groups also showed that the system could be manufactured at clinical scale, with potency varying by less than 1% between production batches.
The study opens up the possibility of gene therapy for genetically derived pathological conditions. However, the study is a preprint(published in bioRxiv) so it has not yet been peer-reviewed. Moreover, the study did not assess behavioural or pathological outcomes in the animals, as its primary aim was to demonstrate efficient genome editing. Evaluating whether this editing translates into therapeutic benefit will be an important next step.
The critical next step is testing this system in a diseased brain: does the editing actually slow or reverse disease progression in the tissue? And beyond pathology, does it improve symptoms in the animal? Those questions remain unanswered, but answering them is now a realistic goal, and that alone is substantial groundwork.
Disclaimer: This article summarizes a preprint that has not been peer-reviewed; readers are encouraged to consult the original publication directly and to interpret the findings accordingly. The reported work was conducted in healthy animals, and no therapeutic claims have been demonstrated or are made here. This article is an honest attempt to report the study accurately, not a comprehensive review of the field. The contents of this article were verified with the authors of the preprint prior to publication.
Declaration of AI use: This article was written with the assistance of Lumo AI for grammar, spell checking, and proofreading.
Reference
Liang, X., Zhou, H., Nizamudeen, Z.A., Kyriakopoulou, E., Evans, A.E., Roudi, S., Estupiñán, H.Y., Rädler, J., Hou, V.W.Q., Daniel, C.D.W., Hernandez-Perez, I., Singh, M., Parsi, P., Lonergan, D.A., Menéndez Berlana, L., Walmsley, R., Chen, Y., Suermondt, J.S.M.T., Mowoe, M.O., Görgens, A., Smith, C.A., Redrup, G.O., Ashmore, L.D., Perez, S., Thapa, K.J., Banerjee, S., Bonner, S.E., Conceicao, M., Gavin, R.L., Hean, J., Horrocks, P.D., Levitin, M.O., Lundin, P., Sharma, H., Tawar, R.G., Liu, L., Gupta, D., Carter, D.R.F., Nordin, J.Z. and El Andaloussi, S., 2026. Efficient genome editing in the non-human primate brain using programmable extracellular vesicles. bioRxiv, posted August 6, 2026. https://doi.org/10.64898/2026.08.05.741964 [Preprint, not peer reviewed]
Leave a Reply