June 02, 2026 —
Circio and GenAssist have entered into a research collaboration to develop circVec-enhanced AAV vectors engineered for in vivo cell therapy and targeted, low-dose systemic gene therapy. The collaboration combines Circio’s circular RNA expression technology with GenAssist’s tissue-targeted, liver-detargeted AAV capsid platform.
The initial focus will be on genetic muscle diseases, an area of high unmet medical need where current AAV gene therapy approaches often require high systemic doses. These high doses can increase the risk of toxicity, particularly through off-target tissue exposure. By combining enhanced transgene expression with more selective muscle-targeted delivery, the companies aim to develop next-generation AAV candidates capable of achieving broad muscle expression at substantially lower doses.
Circio’s circVec platform is designed to improve gene expression from AAV vectors through circular RNA-based expression technology. GenAssist’s second-generation AAV platform is designed to use tissue-specific and detargeted capsids to improve safety, reduce systemic dosing requirements, and minimize off-target toxicity. Together, the companies will evaluate whether circVec-enhanced expression can work synergistically with GenAssist’s targeted capsids and promoters.
In addition to muscle-directed gene therapy, Circio and GenAssist will explore the potential of developing in vivo CAR-T candidates for oncology and autoimmune applications. This part of the collaboration will combine GenAssist’s T-cell-targeting AAV vectors with Circio’s circVec expression cassette, followed by in vitro and in vivo testing. If successful, selected candidates may advance into preclinical development.
The collaboration reflects a broader trend in genetic medicine: next-generation AAV therapies are increasingly being designed through integrated engineering of both delivery and expression. Rather than relying only on conventional AAV serotypes, developers are now combining capsid engineering, promoter design, expression cassette optimization, liver detargeting, and dose reduction strategies to improve therapeutic performance and safety.
If successful, the Circio–GenAssist collaboration could support new AAV-based approaches for genetic muscle disorders and in vivo immune-cell engineering, where targeted delivery, high expression, and lower systemic exposure are critical for clinical translation.
