Oncoinvent ASA

Regulatory Filings • Oct 29, 2025

Oncoinvent Presents Final Safety and Efficacy Results from the Phase 1/2a Trial of Radspherin® to Treat Colorectal Cancer at the 15th PSOGI International Congress on Peritoneal Surface Malignancies

Oncoinvent Presents Final Safety and Efficacy Results from the Phase 1/2a Trial of Radspherin® to Treat Colorectal Cancer at the 15th PSOGI International Congress on Peritoneal Surface Malignancies

Oncoinvent ASA, a clinical-stage radiopharmaceutical company developing

innovative treatments for solid cancers, today announced the presentation of the

previously reported final 18-months safety and efficacy results from  its Phase

1/2a clinical trial (RAD-18-002) evaluating Radspherin® in patients with

peritoneal metastases from colorectal cancer at the 15th PSOGI International

Congress on Peritoneal Surface Malignancies, to be held at the Fira Barcelona

October 29-31, 2025. Radspherin®, direct intraperitoneal targeting with the

alpha-emitter radium-224, aims to eliminate post-surgery micro-metastases and

thereby prevent or delay peritoneal recurrence.

In this Phase 1/2a trial, 36 out of 47 patients received the highest and

recommended intraperitoneal dose of 7 MBq Radspherin® after dose escalation (1,

2, 4 and 7 MBq). The final 18-month data reported that only 10 of these 36

patients (27.8 %) had peritoneal recurrence. Remarkably, only 2 out of the 36

patients experienced peritoneal metastases as the only site of disease

recurrence. Further, at 18 months 61.1% (22 of 36) patients had experienced new

metastases overall, giving a median disease-free survival of 13.5 months.

"We are delighted to have the opportunity to present these encouraging data at

such a highly specialized conference dedicated to peritoneal surface

malignancies," said Øystein Soug, CEO of Oncoinvent. "The theme of this year's

PSOGI conference - 'From small beginnings to global force' - perfectly reflects

our ambitions for the development of Radspherin®."

The results strengthen the potential for Radspherin® as a novel treatment option

for patients with peritoneal metastases from colorectal cancer, demonstrating

both clinical promise, as well as being well tolerated and safe to use,

concludes the presenting author Dr. Stein Gunnar Larsen, Principal Investigator

from the Norwegian Radium Hospital, Oslo University Hospital in Norway in the

presented abstract.

About RAD-18-002

RAD-18-002 was an open label Phase 1/2a trial conducted in patients with

peritoneal metastases from colorectal cancer. 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.

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. One Phase 1 trial and one Phase 1/2a

trial have been completed and one randomized Phase 2 trial is currently ongoing

in the US and Europe. Early clinical efficacy data are highly encouraging, and

no serious toxicity or safety concerns have been reported to date. The

Oncoinvent team consists of approx. 40 employees and 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.

About Radspherin

Radspherin® is an investigational radiopharmaceutical designed for the local

treatment of cancer that has spread to body cavities. It consists of billions 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 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.

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