Circio Demonstrates Increased AAV Potentcy with Circular RNA Technology
In a financial report webcast, the Norwegian biotech presented breakthrough circVec-AAV data showing up to 40x higher protein expression than traditional mRNA-AAVs.
Norwegian Biotech, Circio Holding ASA, has announced a major advance in gene therapy with new in vivodata, which demonstrate the ability of its proprietary circVec-AAV vectors to deliver up to 40 times greater protein expression than conventional mRNA-AAV designs (1). The company’s unique technology produces circular RNA inside patient cells using adeno-associated virus (AAV) vectors that enables much longer-lasting and higher protein production compared to traditional linear mRNA. This approach has shown greater protein expression and vastly extended RNA stability in preclinical studies, promising more potent, durable, and safer treatments at lower doses.
According to Circio’s CTO Dr. Thomas B. Hansen, the company’s latest circVec 3.2 construct dramatically enhances gene delivery, validated by repeat experiments showing a 40-fold signal boost in heart tissue and a 15-fold advantage in the eye compared to leading designs.
“Circio has now completed substantial characterization, engineering and optimization of its circVec expression system for gene therapy. These results make it evident that circular RNA-based expression has the potential to substantially improve the therapeutic potency of AAV vectors in a tissue-specific manner. This creates multiple distinct development opportunities for the circVec platform,” said Hansen in a company press release (1).
With results that could demonstrate a possible breakthrough for AAV-based therapies, Circio has already begun incorporating circVec 3.2 across its pipeline of AAV vectors and is expanding tissue testing on the back of successful pilot experiments. The company aims to leverage its strengthened data package to forge R&D partnerships throughout 2025, envisioning its next-generation circular RNA expression system as a frontrunner in the future of cell and gene therapies.
“Importantly, the latest circVec-AAV in vivo results confirm that the robust circVec advantage applies broadly. The data package now includes several tissues, additional AAV capsids and multiple genetic promoters driving expression. These results broaden and strengthen Circio’s data package, and derisks the technology for potential partners and investors. Our aim is to leverage these new data to establish R&D collaborations with AAV expert companies and validate the performance of the circVec platform in their systems. We already have ongoing dialogues and aim to enter multiple such partnerships during 2025-2026,” commented Dr. Lubor Gaal, CFO of Circio, in the press release (1).
Traditionally, AAV vectors deliver genes using double-stranded DNA templates or, more recently, mRNA-encoding cassettes. While mRNA-AAVs enable rapid protein expression, they are less stable, resulting in shorter effects and often require higher doses that may increase immune responses and toxicity risks. Circio’s circVec introduces a circular RNA format that is much more stable than linear mRNA, showing sustained, high-level protein expression at lower doses with fewer side effects and lower production demands.
AAVs are becoming a leading platform in gene therapy and have been used in approved treatments for inherited retinal diseases (Luxturna), spinal muscular atrophy (Zolgensma), and hemophilia (Hemgenix). Although they are being further tested in clinical trials for neurological disorders, cardiovascular conditions, and certain cancers, circVec’s enhanced stability and efficiency could extend AAVs’ therapeutic reach, enabling safer, more effective treatments across healthcare to broaden the impact of gene and cell therapies worldwide (2).
References
Circio. Circio Presents New circVec-AAV Vectors Showing up to 40x Enhanced Activity in First Half Year Report Webcast. Press Release, Aug. 28, 2025.
Wang, J.H.; Gessler, D.J.; Zhan, W.; Gallagher, T.L.; Gao, G.; Adeno-Associated Virus as a Delivery Vector for Gene Therapy of Human Diseases. Signal Transduction and Targeted Therapy, 2004, 9 (1), 78.