Oncoinvent ASA, a clinical-stage company developing alpha emitter therapies for solid cancers, today reported interim data from the Phase 1/2a trials of Radspherin® for the treatment of peritoneal carcinomatosis. Recruitment for these studies concluded at the end of 2023, with patients now in long-term follow-up. The interim results reaffirm previously published findings on the treatment’s efficacy and provide additional confidence in the ongoing Phase 2 randomized controlled trial of Radspherin® in ovarian cancer patients.
In the Phase 1 study of Radspherin® for ovarian cancer, only 1 out of 10 patients (10%) receiving the selected dose experienced peritoneal recurrence at the 12-month interim readout. This recurrence rate is significantly lower than the expected 25% recurrence in similar patient populations [1-3]. In the Phase 1/2a study of Radspherin® for colorectal cancer, 3 out of 20 patients (15%) receiving the selected dose of 7 MBq experienced peritoneal recurrence after a full 18 months of follow-up. The expected recurrence rate with current standard therapies is approximately 50% over the same period [4]. A total of 36 colorectal cancer patients have received the selected dose, with results from the final 16 patients still pending full follow-up.
“These interim results are exciting as they confirm the efficacy signal we observed in earlier studies and underscore Radspherin®’s potential to achieve local control of peritoneal carcinomatosis, helping patients remain in remission after surgery,” said Øystein Soug, CEO of Oncoinvent. “This reinforces our belief in Radspherin® as an effective treatment for patients with peritoneal carcinomatoses—a challenging condition that is difficult to treat with conventional systemic therapies.”
Dr. Yun Wang, Principal Investigator in the RAD-18-001 study and an expert in gynecologic oncology at The Norwegian Radium Hospital, added, “For ovarian cancer patients, peritoneal carcinomatosis is often present at diagnosis, leading to higher recurrence rates and poorer prognoses. Targeted treatments like Radspherin® could reduce recurrence and potentially extend survival for these patients.”
About Radspherin®
Radspherin® is an investigational radiopharmaceutical designed for local treatment of cancers that have spread to body cavities, such as the peritoneum. It consists of billions of calcium carbonate microparticles containing radium-224, an alpha-emitting radioactive isotope. The alpha particles emitted by radium-224 deliver potent radiation directly to cancer cells, enabling targeted treatment with minimal damage to surrounding healthy tissues. Radspherin® is being evaluated in ongoing clinical studies for peritoneal carcinomatosis from ovarian and colorectal cancers and is administered intraperitoneally following surgical resection of macroscopic tumors.
About the RAD-18-001 and RAD-18-002 Studies
The RAD-18-001 (ovarian cancer) and RAD-18-002 (colorectal cancer) studies are early-phase clinical trials evaluating the safety, tolerability, dosimetry, and efficacy of Radspherin® in patients with peritoneal carcinomatosis. Both studies completed recruitment in late 2023, enrolling a total of 68 patients. The RAD-18-001 study includes 21 patients with platinum-sensitive recurrent ovarian, fallopian tube, or primary peritoneal carcinoma scheduled for secondary cytoreduction, while the RAD-18-002 study includes 47 patients with peritoneal carcinomatosis from colorectal cancer scheduled for cytoreduction and HIPEC (hyperthermic intraperitoneal chemotherapy). These studies are designed to provide crucial data on the optimal dose and the potential of Radspherin® to improve patient outcomes.
About Oncoinvent
Oncoinvent ASA is a clinical-stage radiopharmaceutical company focused on developing innovative therapies for solid tumors. Its lead candidate, Radspherin®, leverages the power of alpha-emitting radionuclides to deliver targeted radiation directly to cancer cells. Oncoinvent has established internal manufacturing and supply capabilities to support the clinical development of Radspherin® and other potential radiopharmaceutical therapies. The company’s team has extensive experience across all stages of radiopharmaceutical development, from preclinical to clinical trials.
