Oslo, Norway, 18 June 2026: Oncoinvent, a clinical-stage radiopharmaceutical company developing Radspherin^®, a receptor-independent alpha-emitting therapy to eradicate cancer cells in the abdominal cavity after surgery with a single, targeted dose, today announces that its ongoing Phase 2 trial of Radspherin^® in patients with peritoneal metastases from ovarian cancer has reached the 50% patient recruitment milestone.

A total of 54 patients have now been enrolled in the study, representing half of the planned trial population. Recruitment momentum has accelerated significantly in 2026, with 11 patients enrolled in the first quarter and 17 patients recruited in the second quarter to date, marking the highest recruitment levels achieved in the study so far. Year-to-date recruitment of 28 patients has already surpassed total enrollment for 2025.

Four new sites have opened for recruitment in 2026 and in total ten hospitals across the United States, Spain, Norway, Belgium, the United Kingdom and Italy are currently active in the trial, and further site activations are ongoing to support continued recruitment.

"Reaching the halfway point for recruitment in our Phase 2 trial is an important milestone for Oncoinvent and reflects the strong commitment of investigators and study sites," said Oystein Soug, CEO of Oncoinvent. "We are pleased to see the steps taken to accelerate recruitment translating into the strong enrollment momentum seen in 2026. Building on the encouraging safety profile and preliminary efficacy signals observed in earlier studies, we look forward to further evaluating Radspherin's potential to improve outcomes for patients with peritoneal metastases from ovarian cancer, who have limited treatment options following surgery."

The Phase 2 trial (ClinicalTrials.gov: NCT06504147) is a randomized controlled study evaluating the efficacy and safety of Radspherin^® in patients with peritoneal metastases from ovarian cancer. The primary objective is to compare progression-free survival between patients receiving Radspherin^® following complete surgical resection and pre-operative chemotherapy, and those receiving standard of care treatment consisting of chemotherapy and surgery alone.

Previous Phase 1 and Phase 1/2a data have demonstrated that Radspherin^® is well tolerated, with no dose-limiting toxicity observed at the recommended dose of 7MBq, and encouraging signals of efficacy. Results from the Phase 1 study in ovarian cancer have been published in the peer-reviewed journal Gynecologic Oncology, and results from the Phase 1/2a study in colorectal cancer have been published in the peer-reviewed journals Journal of Surgical Oncology and Frontiers in Medicine.