Circio and GenAssist jointly announce gene therapy research collaboration for muscle diseases and in vivo cell therapy

• Circio´s proprietary circVec circular RNA platform has demonstrated up to 50-fold enhanced gene expression from AAV vectors in vivo
• GenAssist´s proprietary tissue-specific and liver de-targeting AAV capsids and promoters are designed for targeted delivery and expression in muscle and T-cells
• The objective is to evaluate the potential synergy of Circio´s and GenAssist’s complementary technologies to develop next generation AAVs to address major unmet medical needs in cancer and genetic muscle disease
• The collaboration is part of Circio´s partnering strategy to create next generation gene therapy vectors with improved performance and specificity, thereby solving a major challenge in gene therapy today 

Oslo, Norway, and Suzhou, China 1 June 2026 – Circio Holding ASA (OSE: CRNA), a biotechnology company developing novel circular RNA expression technology for gene and cell therapy, and GenAssist Ltd, a biotechnology company a pioneering next-generation genetic drug company against genetic diseases through its tissue‑specific AAV delivery platform, today jointly announce a research collaboration to develop circVec-enhanced AAV vectors specifically engineered for in vivo cell therapy and targeted, low dose systemic gene therapy.

Genetic muscle disease is an area of major unmet medical need, where current gene therapy’s high dosing requirements are associated with severe toxicity. By integrating Circio´s and GenAssist´s complementary technologies, the parties aim to develop joint next generation of AAV gene therapy candidates. The focus is on addressing genetic muscle conditions where high and broad muscle-specific expression is required at substantially lower therapeutic AAV doses than can be achieved by conventional AAV gene therapy.

"We are incredibly impressed by Circio’s unique circular RNA technology and see tremendous potential in how it can dramatically boost gene expression. Our second-generation AAV platform establishes a new benchmark for safety, utilizing highly tissue-specific, de-targeted capsids to dramatically lower systemic dosing while eliminating off-target toxicity," said Dr. Chunyan He, CEO of GenAssist. "Through our collaboration with Circio, we integrate their unique circular RNA technology—whose exceptional stability and superior transcriptional output ensure robust, sustained expression even at significantly reduced vector loads. This partnership directly addresses the core demands of next-generation genetic medicine, overcoming the traditional dose-expression trade-off to deliver safer and more effective therapies”

In addition, Circio and GenAssist will explore the potential of generating joint in vivo CAR-T candidates for oncology and autoimmune applications. The collaboration will involve production of novel AAVs combining GenAssist´s proprietary T-cell targeting with the circVec expression cassette from Circio. The combined AAVs will subsequently be tested in vitro and in vivo, and if successful, candidates for further development will be nominated for pre-clinical development.

“The targeted AAVs developed by GenAssist have the ability to specifically and efficiently transduce muscle or T-cells upon systemic delivery with near-complete liver de-targeting,” said Dr. Thomas B Hansen, CTO of Circio. “The partnership between Circio and GenAssist will aim to evaluate whether the enhanced circVec expression acts synergistically with these targeted capsids and promoters. This fits perfectly into Circio’s strategy of testing circVec in multiple tissues using different AAV variants, both internally and externally. This will allow us to identify new therapeutic avenues where circVec delivers a benefit, and forge partnerships potentially enabling multiple future development opportunities. China is a particularly interesting geography, with cutting edge science and accelerated pathways to establish early clinical data.”

About GenAssist
GenAssist Ltd. (GenAssist) is a pioneering next-generation genetic drug company against genetic diseases. Suzhou GenAssist Therapeutics co., Ltd is the operation entity of GenAssist Ltd.

GenAssist’s innovation is built on its two proprietary, synergistic platforms. (1) High throughput human genome AAV displaying (HOPE) platform, and (2) All-in-One TAM Base Editor (<4.7 kb). Generated from HOPE platform, the lead capsid LD-8S09, has demonstrated 10 times higher functional muscle transduction of AAV9 (9 times in heart) and near-complete liver de-targeting (3% of AAV9) in NHPs, addressing a key safety hurdle for systemic AAV therapy. Also, HOPE platform has generated some lead T cell and non-TfR CNS-targeting capsids. Preclinical pipeline includes DMD Base editing drugs (50,51,53 skipping) and Hypertrophic Cardiomyopathy gene replacement drugs. Company website: www.genassisttx.com

About Circio
Circio Holding ASA is a biotechnology company developing novel circular RNA expression technology for gene and cell therapy.

Circio has established a unique circular RNA (circRNA) vector expression technology for next generation RNA, DNA and viral therapeutics. The proprietary circVec platform is based on a modular genetic construct designed for efficient biogenesis of multifunctional circRNA inside target cells. The circVec platform has applications in multiple therapeutic settings, including genetic medicine, cell therapy and chronic disease. It has demonstrated 75-fold increased RNA half-life and up to 50-fold enhanced protein expression vs. conventional mRNA-based viral and non-viral vector systems, with the potential to become a new gold-standard gene expression technology. The circVec R&D activities are being conducted by the wholly owned subsidiary Circio AB in Stockholm, Sweden.