Oncoinvent ASA: Notice of Extraordinary General Meeting in connection with the Rights Issue

14 November 2025: Reference is made to the stock exchange announcements published by Oncoinvent ASA (the "Company") on 30 June 2025 and 4 August 2025, and subsequent announcements, regarding the contemplated fully underwritten rights issue in the Company raising gross proceeds of NOK 130 million (the "Rights Issue"). Reference is further made to the prospectus prepared by the Company dated 28 October 2025.

NOT FOR DISTRIBUTION OR RELEASE, DIRECTLY OR INDIRECTLY, IN OR INTO THE UNITED STATES, CANADA, AUSTRALIA, THE HONG KONG SPECIAL ADMINISTRATIVE REGION OF THE PEOPLE'S REPUBLIC OF CHINA OR JAPAN OR ANY OTHER JURISDICTION IN WHICH THE DISTRIBUTION OR RELEASE WOULD BE UNLAWFUL. OTHER RESTRICTIONS ARE APPLICABLE.THIS ANNOUNCEMENT DOES NOT CONSTITUTE AN OFFER OF ANY OF THE SECURITIES DESCRIBED HEREIN.

The Company hereby calls foran extraordinary general meeting to be held on Friday 5 December 2025 at 12:00 hours (CET) to, inter alia, resolve (i) the approval of an audited interim balance sheet, (ii) the share capital reduction required to carry out the Rights Issue, and (iii)to ratify and update the resolution to increase the share capital in connection with the Rights Issue adopted at the general meeting of the Company on 4 August 2025.

The extraordinary general meeting will be held electronically through Lumi AGM.

For more information, please see the attached notice of the extraordinary general meeting.

For further information, please contact:

Oystein Soug, Chief Executive Officer

Email: soug@oncoinvent.com

This information is subject to the disclosure requirements pursuant to Section 5-12 of the Norwegian Securities Trading Act.

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 in the peritoneum 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 in ovarian cancer 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. Oncoinvent runs a state-of-the-art manufacturing facility to produce drug products for clinical trials in Nydalen, Oslo. Oncoinvent is listed on the Oslo Stock Exchange.

About Radspherin®

Radspherin® is an innovative internal radiation therapy designed to directly target microscopic metastases in the abdominal cavity following surgery. Radspherin® is currently in development as a post-surgical treatment for patients with cancer that has spread to the abdominal cavity - a group with very limited treatment options today. The drug candidate offers a distinctly unique therapeutic approach with several differentiating features, including the use of radium-224, single-dose treatment with a sustained therapeutic effect, non-systemic administration, direct targeting and an exceptional dose-to-tumor ratio, maximizing efficacy while limiting harm to healthy tissue