Oncoinvent ASA has announced promising interim data from its Phase 1/2a studies evaluating Radspherin® for the treatment of peritoneal carcinomatoses. The studies, which concluded recruitment at the end of 2023, are currently in long-term follow-up. The data reinforces previously published efficacy results and bolsters confidence in the ongoing randomized controlled Phase 2 clinical trial of Radspherin® in ovarian cancer patients.
Reduced Recurrence Rates Observed
Interim results from the Phase 1 study in ovarian cancer revealed that only 1 out of 10 patients (10%) who received the selected dose experienced peritoneal recurrence at the 12-month mark. This is compared to an expected recurrence rate of 25% in similar populations, as indicated by previous studies. Similarly, the second interim readout from the colorectal cancer study showed that only 3 of 20 patients (15%) who received the selected dose of 7 MBq had peritoneal recurrence after the full 18-month follow-up period. Current standard therapy typically results in a peritoneal recurrence rate of approximately 50% after 18 months.
Oystein Soug, Chief Executive Officer of Oncoinvent, stated, “We are excited to announce the interim results of our Phase1/2a studies of Radspherin®, confirming a positive efficacy signal and demonstrating Radspherin’s® ability to enable local control in the peritoneum, thus ensuring patients remain in remission after surgery.” He added that these results increase confidence in the further development of Radspherin® as an effective treatment option for patients suffering from peritoneal carcinomatoses, a condition that is notoriously difficult to treat effectively with systemic therapy.
Clinical Significance
Yun Wang, MD PhD, Department of Gynecologic Oncology, The Norwegian Radium Hospital, Oslo University Hospital, and principal investigator in the RAD-18-001 study, noted the significance of these findings for ovarian cancer patients. “Patients with ovarian cancer often have peritoneal carcinomatoses already at diagnosis, giving them higher recurrence rate and worse prognosis - so an effective treatment targeted specifically at these carcinomatoses could reduce recurrence and prolong survival,” she said.
About Radspherin
Radspherin® is an investigational radiopharmaceutical designed for local cancer treatment in body cavities. It comprises billions of calcium carbonate microparticles containing radium-224, an alpha-emitting radionuclide. The mechanism of action involves the decay of radium-224, which emits highly potent alpha-particles, delivering targeted ionizing radiation to cancer cells. Radspherin® is currently under investigation in clinical studies for the treatment of peritoneal carcinomatoses originating from ovarian and colorectal cancer. It is administered intraperitoneally following surgical resection to remove all macroscopic tumors.
Study Details
The RAD-18-001 study (n=21, phase 1) focused on patients with peritoneal carcinomatoses from platinum-sensitive recurrent epithelial ovarian, fallopian tube, or primary peritoneal carcinoma scheduled for secondary cytoreduction. The RAD-18-002 study (n=47, phase 1/2a) included patients with peritoneal carcinomatoses from colorectal cancer scheduled for cytoreduction and HIPEC. Both studies aimed to evaluate the dose, safety, tolerability, dosimetry, and efficacy signals of Radspherin®.
