Oslo, Norway, 8 December 2025 – Oncoinvent, a clinical stage, radiopharmaceutical company developing innovative treatments for solid cancers, today announced the publication of 12-month data from its Phase 1 study of patients with platinum-sensitive recurrent ovarian cancer and peritoneal carcinomatosis. The results from the first patients have been published in the respected peer-reviewed journal Gynecologic Oncology, under the title: “First experience with intraperitoneal 224Ra-labeled microparticles after cytoreductive surgery in patients with peritoneal recurrence of platinum-sensitive epithelial ovarian cancer.”

“We are proud to announce that our article has been published in Gynecologic Oncology. This recognition underscores the importance of our research and validates our ongoing efforts. As our phase 2 study progresses in patients with peritoneal metastasis from ovarian cancer, we remain fully committed to advancing new treatment options to address this urgent medical need,” said Kari Myren, Chief Medical Officer at Oncoinvent.

The primary objectives of the phase 1 study were to evaluate the safety and tolerability of the alpha emitting therapy using ²²⁴Ra-labeled microparticles (Radspherin®) and to determine the recommended dose for subsequent clinical development. Initial experiences indicate that all dose levels were well tolerated, no dose limiting toxicity was observed during dose escalation and the highest dose of 7 MBq was selected as the recommended dose for the expansion phase.  Alongside the now published  12-month data, Oncoinvent has also released topline 24-month follow-up data for the phase 1 study in ovarian cancer patients.

A randomized controlled phase 2 study is ongoing to evaluate the efficacy and safety of Radspherin® in patients with peritoneal metastasis from ovarian cancer. The primary aim is to compare progression-free survival (PFS) between two groups: those who receive Radspherin® following complete surgical resection after pre-operative chemotherapy, and those treated with pre-operative chemotherapy and surgery alone. Further details can be found at clinicaltrials.gov.

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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, UK 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 Oslo Stock Exchange.

 

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 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:

Øystein Soug, Chief Executive Officer
Email: soug@oncoinvent.com

Renate Birkeli, Director Investor Relations

Email: birkeli@onconinvent.com

 

Optimum Strategic Communications

Mary Clark, Zoe Bolt, Elena Bates

+44 (0) 203 882 9621

oncoinvent@optimumcomms.com