Oslo, Norway, 25 September 2023 - Circio Holding ASA (OSE: CRNA) today announces
that an abstract describing its circular RNA platform has been accepted for
poster presentation at the 15th international adenovirus meeting in Brac Island,
Crotia.

The abstract describes the development of Circio's proprietary circAde vector
system for therapeutic protein expression. The abstract describes the
development of Circio's proprietary circVec vector system for therapeutic
protein expression. Key elements necessary for circRNA biogenesis were
systematically screened and optimized to facilitate high yield circRNA
expression. Additionally, we describe the development of circVac and circAde
vector systems for vaccine and cancer immunotherapy platforms, respectively.
 Here, we show the importance of vector design for durable circRNA expression
and functionality of our viral vector, circAde. Our results highlight the
potential of the circVec platform for the development of novel, more effective
strategies for the treatment of diseases in which durable transgene expression
is desirable.

The poster is scheduled for presentation today, 25 September 2023, and will be
available on Circio's website (https://www.circio.com/en/circvec-platform/)
after the presentation.

Poster      circAde, a viral vector system for
title:      high and durable protein expression
Date and    Monday 25 September 2023, 20:00-
time:       21:30 CEST
Location:   Brac Island, Croatia
Abstract    16
number:
Presenter:  Eoghan O'Leary, Director RNA
            Research

About The International Adenovirus Meeting

The International Adenovirus Meeting is the gathering point for scientists
interested in all aspects of adenovirus infection. Internationally leading
experts will share their ideas and latest results on adenovirus detection in
nature