· CircioŽs durable circVec DNA vectors will be combined with the Entos Fusogenix
PLV delivery technology
  · The combination is expected to enhance circVec DNA vector delivery
efficiency and reduce toxicity compared to LNP-formulations
  · The combined technologies can allow future joint development of novel,
potent, repeat-dosable therapeutic candidates for genetic medicine, chronic
disease, and vaccines

Oslo, Norway, Edmonton, Canada and London, United Kingdom, 3 April 2025 - Circio
Holding ASA (OSE: CRNA), a biotechnology company developing powerful circular
RNA technology for next generation nucleic acid medicine, and Entos
Pharmaceuticals U.K. Ltd. (Entos), a clinical-stage genetic medicines company,
today announce the initiation of a research collaboration. The collaboration
will involve joint development and in vivo delivery testing of Circio's
optimized circular RNA expression vectors (circVec) using the Entos proprietary
FusogenixT PLVT nucleic acid delivery technology.

Under the collaboration, Entos will develop and validate PLV-formulations of
CircioŽs circVec DNA vectors and perform technical testing in vivo. Initial data
from the collaboration is expected in the next three to six months. If
successful, the results will create the foundation for a continued collaboration
to develop and test future circVec-PLV therapeutic candidates with potential
applications in genetic medicine, chronic disease, and vaccines.

Financial details were not disclosed.

"Entos has demonstrated efficient and safe delivery of synthetic non-viral DNA
vectors, both in mouse models, primates and clinical trials," said Dr. Thomas
Hansen, CTO of Circio. "The unique PLV chemistry enables direct fusion with the
cell membrane and bypasses the endosomal uptake pathway. This feature has been
shown to enhance delivery efficiency and reduce toxicity of DNA vectors. It is
therefore a logical step for Circio to enter this research collaboration with
Entos to explore the potential synergy of combining our complementary expression
and delivery technologies. If successful, this partnership will aim to provide a
joint platform for generating future therapeutic candidates in several disease
areas of high unmet medical need."

"Entos is currently partnering with a number of key international genetic
medicine companies for the expansion of the use of our Fusogenix PLV drug
delivery system to enable the delivery of nucleic acid to target cells through
direct fusion," said Jason Ding, CBO of Entos Pharmaceuticals. "We have selected
to partner with Circio given their unique and impressive approach to circular
RNA vector expression technologies for next generation nucleic acid medicine.
This collaboration will seek to use Fusogenix PLV to enhance Circio's circVec
DNA vector delivery efficiency and reduce toxicity compared to LNP-formulations.
This could have a considerable impact in novel applications in genetic medicine,
chronic disease and vaccines."

About Entos Pharmaceuticals

A new reality in genetic medicine lies ahead, one that will be ushered in with
the advent of safe, effective, and re-dosable nucleic acid delivery
technologies. Since its inception in 2016, Entos® has been dedicated to
advancing next-generation genetic medicines using our proprietary FusogenixT
PLVT drug delivery system. The Fusogenix PLV platform is formulated with FAST
proteins to enable the delivery of nucleic acid to target cells through direct
fusion. Entos is pioneering the development of life-changing medicines for
patients and has partnered with global companies, such as Eli Lilly, to
accelerate and expand the impact of our platform. Entos Pharmaceuticals Inc. is
headquartered in Edmonton, Canada, with its wholly owned U.S. and U.K.
subsidiaries based in San Diego, California and London, United Kingdom,
respectively. For more information,
visit www.entospharma.com (https://cts.businesswire.com/ct/CT?id=smartlink&url=h
t
tp%3A%2F%2Fwww.entospharma.com%2F&esheet=54222476&newsitemid=20250311006058&lan=
e
n-US&anchor=www.entospharma.com&index=4&md5=4b09d2fcdebcd21cf56ed49f903e95a5),
or follow Entos
on LinkedIn (https://cts.businesswire.com/ct/CT?id=smartlink&url=https%3A%2F%2Fw
w
w.linkedin.com%2Fcompany%2Fentospharmaceuticals%2F&esheet=54222476&newsitemid=20
2
50311006058&lan=en
-US&anchor=LinkedIn&index=5&md5=f47dd3b4097dc5420ac5081c65bb235e).

Entos Pharmaceuticals Contacts

Corporate:
John Lewis, Ph.D., Founder and CEO
[email protected]

Media:
Perrin Beatty, Ph.D.
[email protected]
+1-800-727-0884

About Circio

Building next generation RNA technology for nucleic acid medicine

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.

For further information, please contact:
Erik Digman Wiklund, CEO
Phone: +47 413 33 536
Email: [email protected]

Neil Hunter - Hunter PR
Phone:+44 7821 255568 (http://tel:+447821255568)
Email: [email protected]