Oncoinvent Presents 15-Month Safety and Efficacy Data from Ongoing RAD-18-002 Phase 1/2A Trial of Radspherin® in Colorectal Cancer Patients at the 2023 ASCO Annual Meeting

Median PFS (progression free survival) was not reached at 15 months, and no patients at recommended dose of 7 MBq had peritoneal recurrences

All dose levels of Radspherin^®, including recommended dose of 7 MBq, were well tolerated at 15 months with no serious adverse events related to Radspherin^® reported

Radspherin^® is currently being evaluated in two ongoing Phase 1/2A trials for the treatment of peritoneal carcinomatosis from colorectal cancer and ovarian cancer

Poster discussion session on June 5, 2023 at 1:15 p.m. ET

OSLO, Norway--(BUSINESS WIRE)--Oncoinvent AS, a clinical stage company advancing alpha emitter therapy across a variety of solid cancers, today announced the presentation of new 15-month safety and efficacy data from its ongoing Phase 1/2A clinical trial evaluating the safety, tolerability, and signal of efficacy of Radspherin^® in patients with peritoneal carcinomatosis from colorectal cancer at the 2023 American Society of Clinical Oncology (ASCO) Annual Meeting, being held at McCormick Place in Chicago, IL from June 2- 6, 2023. The poster, titled “15-month safety and efficacy data after intraperitoneal treatment with ²²⁴Radium-labelled microparticles after CRS-HIPEC for peritoneal metastasis from colorectal cancer” will be presented by Dr Stein Larsen from the Norwegian Radium Hospital during the “Gastrointestinal Cancer – Colorectal and Anal” session from 8:00 a.m. to 11:00 a.m. ET on June 5, 2023. There will additionally be a poster discussion session from 1:15 p.m. to 2:45 p.m. on June 5, 2023.

“We are excited to share these compelling and critical safety and efficacy 15-month data at ASCO, which continue to demonstrate that recommended dose levels of Radspherin^® are well tolerated and now also showing promising effects on recurrence levels,” said Kari Myren, Chief Medical Officer of Oncoinvent. “The data presented continue to give us confidence in the potential of Radspherin^® to prolong time to peritoneal recurrence and improving progression free survival in patients with a difficult prognosis. In particular, with the recommended dose cohort of 7 MBq, only 25% of patients recurred and none of these patients had peritoneal recurrences; these data are highly encouraging and represents an improvement compared to the expectations of the current standard of care. We look forward to presenting longer-term results of Radspherin^® for both ongoing Phase 1/2A studies to treat peritoneal carcinomatosis from colorectal cancer and ovarian cancer, respectively.”

Details of the poster presentation are as follows:

Poster Presentation Title: 15-month safety and efficacy data after intraperitoneal treatment with ²²⁴Radium-labelled microparticles after CRS-HIPEC for peritoneal metastasis from colorectal cancer.
Session Title: Poster Discussion Session - Gastrointestinal Cancer—Colorectal and Anal
Poster Session Display Date and Time: 6/5/2023, 8:00 a.m.-11:00 a.m. ET
Poster Board Number: 218
Poster Discussion Session Date and Time: 6/5/2023, 1:15 p.m.-2:45 p.m. ET

This Phase 1/2A study is designed to evaluate the safety, tolerability, and signal of efficacy of Radspherin^® injected intraperitoneally two days after the completion of CRS-HIPEC. A dose of 7 MBq was recommended following the completion of dose escalation 1-2-4-7 MBq. A total of 23 patients with peritoneal metastasis from colorectal cancer were enrolled; 12 received the recommended dose of 7MBq with 9 receiving a single dose and 3 receiving split doses of 3.5 MBq each. Assessment of safety and efficacy was performed every three months; this dataset includes safety and survival data at the 15-month mark.

Key results:

• Only 2.5% of all adverse events reported were found to be related to Radspherin^®, all of which were grade 1-2
• No serious adverse events were reported as related to the treatment of Radspherin^®
• At 15 months, 39% of patients had recurred, with less than half recurring in the peritoneum
• 25% of patients recurred with the recommended dose cohort of 7MB but none had peritoneal recurrences
• Median PFS was not reached in both populations

Radspherin^® is also being evaluated at the 7Mbq dose in a Phase 1 clinical trial in subjects with peritoneal carcinomatosis from ovarian cancer following complete cytoreductive surgery.

About Oncoinvent

Oncoinvent AS is a clinical stage company developing innovative radiopharmaceutical technology that delivers precise, alpha-emitting particles across solid cancers. By leveraging internal manufacturing and supply chain capabilities to enable a clinical supply of radioisotopes, the company is advancing a pipeline of novel products that use alpha particles, a higher Linear Energy Transfer (LET) form of radiation, that can potentially eradicate cancer cells. Oncoinvent’s lead candidate, Radspherin^®, is designed for treatment of metastatic cancers in body cavities, and its versality allows it to be deployed for the treatment of a variety of cancer indications. Radspherin^® is in two ongoing clinical studies to treat peritoneal carcinomatosis from both ovarian cancer and colorectal cancer.