• Circio unveils extensive circVec-AAV data package in the poster session on 13 May and as an oral presentation on 15 May at the 2026 ASGCT Annual Meeting in Boston
• The data supports the potential of the circVec circular RNA-based expression system to enable substantial dose reduction, addressing a key challenge for developing safer and lower cost AAV gene therapies
• ASGCT is currently the most important and prestigious gene and cell therapy conference globally

Oslo, Norway, 15 May 2026 – Circio Holding ASA (OSE: CRNA), a biotechnology company developing novel circular RNA expression technology for gene and cell therapy, today publishes the poster and slides that were presented at the American Society of Gene and Cell Therapy Annual Meeting in Boston.

In the oral presentation, Circio´s CEO Dr. Erik D Wiklund provided an overview and the latest developments of the circVec circular RNA-based gene expression platform. The superior stability of circular RNA enables enhanced and prolonged gene expression and can be deployed to enable more potent and safer gene and cell therapies. In the context of AAV gene therapy, circVec yields up to 40 and 50-fold increased gene expression in heart and eye, respectively. High dosing requirements and associated toxicities remain critical barriers to the broader clinical application of AAV gene therapy. Preclinical studies suggest that the circVec technology can enable AAV dose reduction, potentially improving safety and expanding treatment opportunities for patients with rare genetic disorders.

The poster presentation detailed an extensive circVec-AAV in vivo data package in heart tissue. circVec shows significant promise for cardiac genetic disease, delivering 40-fold increased gene expression from AAV9 vectors compared to conventional AAV technologies. Importantly, molecular analyses performed on heart tissue confirm that the circVec advantage, as expected, is driven by the superior durability of circular RNA. Moreover, these findings are consistent across a broad dose range, with circVec demonstrating enhanced expression and distribution within the heart across all dose levels.

“ASGCT is the most important event of the year in the gene therapy field, and Circio is very honored to be selected for an oral presentation in this forum of global expertise,” said Dr. Erik D Wiklund, CEO of Circio. “The ASGCT meeting is also an excellent opportunity to connect with existing and prospective collaboration partners. The robust circVec data package, combined with high demand for novel circular RNA approaches, continues to trigger substantial visibility for and interest in Circio and our unique technology platform.”

The ASGCT annual meeting is the largest and most prestigious gene and cell therapy conference globally, and widely attended by pharmaceutical and biotech professionals, academics, patient advocacy groups and life science media.

Circio presentations at ASGCT Annual Meeting 2026:

Circular RNA-based AAV gene therapy for cardiomyopathies enhances transgene expression levels, reduces liver off-targeting and minimizes cellular stress

O´Leary et al., poster presentation
Session: Cardiac disease models, Wednesday 13 May 2026

circVec: A powerful circular RNA expression platform that enhances AAV transgene output and enables significant dose reduction

Dr. Erik D Wiklund, oral presentation
Session: New insights into AAV genome biology, Friday 15 May 2026

The materials are attached to this press release and are available on the Circio website.