Data demonstrate sustained peritoneal disease control and reinforce the
potential of Oncoinvent's novel radiopharmaceutical therapy to target peritoneal
disease in colorectal cancer

Oncoinvent ASA, a clinical-stage radiopharmaceutical company developing
innovative treatments for solid cancers, is thrilled to announce positive
topline data from the Phase 1/2a clinical trial (RAD-18-002) evaluating
Radspherin® in patients with peritoneal metastases originating from colorectal
cancer. 

Reducing peritoneal recurrence in colorectal cancer is critically important
because peritoneal metastases are associated with a particularly poor prognosis
and significantly lower overall survival compared to other forms of recurrence .
The development of peritoneal metastases is not only linked to worse survival,
but also to distressing symptoms, making disease management more challenging and
often resulting in treatment interruptions and repeated hospitalizations. 

Standard therapies for peritoneal metastases are limited, and the only treatment
option with curative intent is surgery, which aims to remove as much tumor as
possible in the peritoneal cavity.  However, surgical resection leaves behind
microscopic deposits of cancer cells, giving rise to new peritoneal metastases
and disease progression. Radspherin®, direct intraperitoneal targeting with the
alpha-emitter radium-224, aims to eliminate these post-surgery micro-metastases
and thereby prevent or delay peritoneal recurrence. 

In this single-arm trial of 47 patients, 36 received Radspherin® at a 7 MBq
dose. The primary endpoint-peritoneal recurrence-free survival (pRFS)-yielded
remarkable results:

o	Only 27.8% (10 of 36) experienced peritoneal disease recurrence at 18 months,
a marked reduction compared to published data for standard of care, where
approximately 50% of patients typically see peritoneal recurrence at this stage 
o	At 18 months, 61.1% (22 of 36) of patients had experienced any recurrence, but
notably, just 22.7% (5 of 22) had peritoneum as the first site of recurrence
o	Final data from all 47 treated patients across dose levels further reinforce
the favorable safety profile of Radspherin®

Additional results will be published upon completion of the full dataset
analysis.

"It's highly encouraging to see patients treated with Radspherin® achieving
outcomes that exceed expectations for this challenging population. As a
clinician, I'm hopeful that this promising therapy will become an option I can
offer to future patients in need," said Dr. Stein Gunnar Larsen, Principal
Investigator at the Oslo University Hospital, Norway.

Prof. Dr. Wilhelm Graf, Principal Investigator at Uppsala University Hospital,
Sweden, added: "Colorectal peritoneal metastases present a major therapeutic
challenge with limited effective options, and these findings support the
potential of a novel approach that demonstrates both clinical promise and a
favorable safety profile."
"We are inspired and motivated by these compelling data. They reinforce our
belief in Radspherin®'s potential as a novel treatment targeting peritoneal
metastases and justify continued advancement of the program," said Oystein Soug,
CEO of Oncoinvent.  "We extend our deepest gratitude to the patients,
investigators, and clinical teams who made this trial possible."

Radspherin® is currently investigated in an ongoing phase 2 trial evaluating the
treatment of peritoneal carcinomatosis from ovarian cancer. A positive safety
review of the lead-in cohort was announced in Q1 2025, and the trial is
currently recruiting patients according to plan in European and US sites in the
randomized phase.

About RAD-18-002
RAD-18-002 was an open label Phase 1/2a trial conducted in patients with
colorectal peritoneal metastases. The trial was designed to evaluate dosing,
safety and tolerability, and signal of efficacy of intraperitoneally
administered Radspherin® following complete surgical resection and Hyperthermic
Intraperitoneal Chemotherapy (HIPEC). A total of 47 patients were enrolled
across sites in Norway and Sweden, with 36 patients receiving the recommended
dose of 7 MBq.

About Radspherin®
Radspherin® is an investigational radiopharmaceutical designed for the local
treatment of cancer that has spread to body cavities. It consists of calcium
carbonate microparticles containing the radioactive material radium-224. The
mode of action is the decay of radium-224 emitting alpha-particles, a highly
potent form of ionizing radiation. Radspherin® is investigated in ongoing
clinical studies to treat peritoneal carcinomatoses from ovarian and colorectal
cancer and it is administered intraperitoneally after surgical resection with
removal of all macroscopic tumors. 

About Oncoinvent
Oncoinvent is a clinical-stage biotechnology company developing novel
radiopharmaceutical therapies against cancer. The lead product candidate,
Radspherin®, uses the alpha-emitting radionuclide radium-224, directly targeting
micro-metastases post-surgery, harnessing the benefits of modern
radiopharmaceuticals without the complexities of biological targeting.
Oncoinvent is investigating the safety and efficacy of Radspherin® in a clinical
development program in two indications. In addition to the currently finalized
phase 1/2a trial in colorectal cancer, one phase 1 trial and one randomized
phase 2 trial, both in ovarian cancer, are ongoing in the US, UK and Europe.
Preliminary clinical efficacy data are highly encouraging, and no serious
toxicity or safety concerns have been reported to date. The experienced
Oncoinvent team runs a state-of-the-art manufacturing facility to produce drug
products for clinical trials in Nydalen, Oslo. Oncoinvent is listed on the
Euronext Growth Oslo.

Forward-Looking Statements
All statements other than statements of historical facts contained in this press
release are forward-looking statements and are not a representation that
Oncoinvent 's plans, estimates, or expectations will be achieved. These
forward-looking statements represent Oncoinvent' s expectations as of the date
of this press release, and Oncoinvent disclaims any obligation to update the
forward-looking statements. These forward-looking statements are subject to
known and unknown risks and uncertainties that may cause actual results to
differ materially, including with respect to whether the results of clinical or
other studies will support the use of our product offerings, the impact of
results of such studies, our expectations of the reliability, accuracy and
performance of our tests, or of the benefits of our tests and product offerings
to patients, providers and payers.

For further information, please contact:
Oystein Soug, Chief Executive Officer
Email: soug@oncoinvent.com 

Tore Kvam, Chief Financial Officer 
Email: kvam@oncoinvent.com