Circio Holding ASA

Report Publication Announcement • May 28, 2025

Circio presents new and differentiating circVec data and corporate update in live webcast

Circio presents new and differentiating circVec data and corporate update in live webcast

· Significant advantage of circVec confirmed in vivo for therapeutically

relevant AAV variants and DNA formats

· Distinct expression biology positions circular RNA expression systems as a

novel alternative for diseases where current approaches are less suitable

· Early data shows 10-fold increase in potency for circVec AAV in heart,

opening development opportunities in cardiac genetic disease

Oslo, Norway 28 May 2025 - Circio Holding ASA (OSE: CRNA), a biotechnology

company developing powerful circular RNA technology for next generation nucleic

acid medicine, announces it is hosting a live update webcast at 10:00am CET

today Wednesday 28 May 2025. In the webcast, Circio management will present

novel in vivo data for its circular RNA expression technology. This data

broadens the therapeutic development and partnership opportunities of the

circVec platform.

In the presentation, Circio´s CTO Dr. Thomas B Hansen will showcase the latest

circVec DNA gene and cell therapy in vivo data. circVec continues to perform

substantially better than equivalent mRNA vectors in multiple settings. In

addition to increased and prolonged protein expression, a distinct tissue

expression pattern is emerging, pointing to development opportunities in

specific disease areas.

"It is becoming evident that circular RNA-based expression has a completely

different biology compared to mRNA vectors. This creates a unique set of

opportunities for Circio´s circVec platform," said Dr. Thomas B Hansen, CTO of

Circio. "Interestingly, the increased and prolonged expression level is more

pronounced in certain tissues, and absent in others, which gives us clear

targets to proceed with. Muscle, heart and spleen have emerged as sites where

circVec is particularly advantageous. As a result, we have identified several

potential development opportunities in muscle and cardiac genetic disease, which

are not well served by conventional approaches."

Substantial progress has been made on circVec-AAV gene therapy development. Mice

have been monitored for up to six months following one systemic administration,

showing a 50% increase in total expression level vs. mRNA-AAV. Importantly, post

mortem ex vivo tissue and organ analysis after six months reveal a unique signal

distribution. Circio is in the process of exploring these observations in

further detail, and early data indicate 10-fold increased potency for circVec

-AAVs designed for specific expression in heart.

"The heart AAV data indicating up to a 10-fold increase in potency for circVec

is precisely what we have been working towards achieving," said Dr. Erik D

Wiklund, CEO of Circio. "Our latest data package points to a strong advantage

for circVec in tissue-specific AAV gene therapy and DNA-format in vivo cell

therapy. Following broad interest at the recent ASGCT 2025 conference, Circio is

in the process of discussing the latest results with experts in these fields and

aim to continue development both in house and through partnerships. This will

allow us to generate external validation of the circVec technology and

accelerate platform development towards defining Circio´s first therapeutic

candidates."

In the webcast, CEO Dr Erik D Wiklund will also provide a corporate update, and

discuss the upcoming annual general meeting on 5 June 2025.

Presenters:

CEO Dr. Erik Digman Wiklund

CTO Dr. Thomas Birkballe Hansen

Time: 10:00 CEST on 28 May 2025

Click here to access Teams

webcast (https://teams.microsoft.com/meet/3919530790393?p=D2tS9HOrDxAFf5WhLj)

Meeting ID: 391 953 079 039 3

Passcode: PB2gk7wt

Questions can be submitted in advance by email to Erik D Wiklund:

erik.wiklund@circio.com or directly in the live webcast

A recording of the webcast will be made available on the Circio

webpage (http://www.circio.com/)

For further information, please contact:

Erik Digman Wiklund, CEO

Phone: +47 413 33 536

Email: erik.wiklund@circio.com

Neil Hunter - Hunter PR

Phone:+44 7821 255568 (http://tel:+447821255568)

Email: neiljameshunter@gmail.com

This information is considered to be inside information pursuant to the EU

Market Abuse Regulation (MAR) and is subject to the disclosure requirements

pursuant to MAR article 17 and section 5-12 of the Norwegian Securities Trading

Act.

This stock exchange announcement was published by Erik Digman Wiklund, CEO, on

behalf of the Company, at the time and date stated above in this announcement.

About Circio

Building circular RNA expression systems for enhanced gene and cell therapies

Circio Holding ASA is a biotechnology company developing powerful circular RNA

vector expression technology for next generation nucleic acid medicine.

Circio has established a unique circular RNA (circRNA) vector expression

platform for novel DNA, RNA and viral therapeutics. The proprietary circVec

technology is based on a modular genetic cassette design for efficient

biogenesis of multifunctional circRNA inside cells, which can be deployed in

multiple therapeutic settings, including genetic medicine, cell therapy and

chronic disease. The circVec platform has demonstrated up to 15-fold enhanced

and more significantly more durable protein expression vs. classic mRNA vector

systems and has the potential to become a new gold-standard platform technology

for nucleic acid and viral therapeutics in the future. The circRNA R&D

activities are being conducted by the wholly owned subsidiary Circio AB based at

the Karolinska Institute in Stockholm, Sweden.