Cellectis Publishes Nature Communications Article on a Non-Viral Gene Editing Process Enabling Efficient Gene Insertion in Hematopoietic Stem Cells

NEW YORK, Nov. 19, 2025 (GLOBE NEWSWIRE) — Cellectis (Euronext Growth: ALCLS – NASDAQ: CLLS), a clinical-stage biotechnology firm, has published findings in Nature Communications that establish circular single-stranded DNA (CssDNA) as a highly effective non-viral DNA donor template for gene integration in hematopoietic stem and progenitor cells (HSPCs). This research highlights the potential for long-term therapeutic benefits through gene editing in HSPCs, which has traditionally relied on viral vectors such as AAV6, raising concerns about safety and efficacy.

Over a decade, non-viral DNA template delivery has become a viable alternative, commonly used in conjunction with nucleases to edit defective genes. Cellectis has advanced its TALEN® technology and CssDNA donor templates to create a precise gene insertion method, facilitating the integration of larger genetic sequences within specific HSPC populations. The study’s results indicate that CssDNA offers 3–5 times higher knock-in efficiency than linear single-stranded DNA (LssDNA), exceeding 40%. CssDNA can also insert genes at multiple locations within HSPCs, applicable to other cell types such as primary T cells.

Additionally, comparative studies suggest that CssDNA-edited HSPCs demonstrate better engraftment and maintenance of gene edits in murine models compared to AAV6-edited HSPCs. The findings position CssDNA as a notable advancement in the quest for innovative cell and gene therapies.

The article can be viewed on Nature Communications’ website here.