Oncolytics Biotech Reports Encouraging Data for Pelareorep in KRAS-Mutant Metastatic Colorectal Cancer
Oncolytics Biotech Inc. (NASDAQ: ONCY) has released new clinical and translational data supporting the potential of its lead immunotherapy candidate, pelareorep, in second-line metastatic colorectal cancer (mCRC), particularly in patients with KRAS-mutant, microsatellite-stable (MSS) disease—one of the most difficult subgroups to treat.
In a previously completed clinical study evaluating pelareorep in combination with standard-of-care therapy, 33% of patients with KRAS-mutant MSS mCRC achieved an objective response. This compares favorably with historical objective response rates of approximately 6% to 11% for the current standard second-line regimen of Avastin (bevacizumab) plus FOLFIRI. Patients receiving the pelareorep-based combination also more than doubled progression-free survival and overall survival compared with those treated with bevacizumab and FOLFIRI alone.
Beyond clinical outcomes, a separate translational analysis of paired tumor biopsies provided mechanistic insight into pelareorep’s activity. The analysis showed a meaningful increase in KRAS-mutant–specific T-cell populations following treatment, suggesting that pelareorep may enhance immune recognition and targeting of KRAS-driven tumors. These findings are particularly notable given that KRAS-mutant MSS colorectal cancers typically show poor responses to checkpoint inhibitors and other immunotherapies. A full presentation of the translational data is expected at an upcoming medical meeting.
“Colorectal cancer is central to our emerging gastrointestinal tumor platform strategy for pelareorep, with a projected total addressable market of approximately $20 billion by 2033,” said Jared Kelly, Chief Executive Officer of Oncolytics Biotech. “The combination of a 33% response rate and KRAS-specific immune activation underscores pelareorep’s potential to become a transformational therapy in a setting where treatment options remain limited.”
Dr. Sanjay Goel, Professor of Medicine at Rutgers Cancer Institute of New Jersey and a leading investigator in gastrointestinal oncology, highlighted the significance of the findings. He noted that achieving a 33% objective response rate in KRAS-mutant MSS colorectal cancer is highly unusual and merits further investigation, adding that the translational data strengthens confidence in the biological mechanism underlying the observed clinical benefit.
Based on the combined clinical and mechanistic evidence, Oncolytics plans to advance pelareorep into a controlled study in second-line KRAS-mutant MSS mCRC, following discussions with regulatory authorities and key opinion leaders. Unlike prior investigator-sponsored trials, the company intends to sponsor this next study directly, allowing for greater analytical rigor, full data ownership, and clearer regulatory pathways. Management believes this approach could support future regulatory submissions and help establish pelareorep as a new treatment paradigm in KRAS-mutant colorectal cancer.
Together, the data reinforce pelareorep’s potential as a precision immunotherapy and strengthen its positioning as a platform candidate across gastrointestinal cancers with significant unmet need.
