SAN DIEGO, Sept. 2, 2025 – Oncolytics Biotech® Inc. (Nasdaq: ONCY), a clinical-stage immunotherapy company, announced updated clinical safety data for its lead therapeutic candidate, pelareorep, with new evidence demonstrating a favorable safety profile across multiple gastrointestinal (GI) cancers. The data, now including more than 300 GI cancer patients and over 1,200 total patients, underscore pelareorep’s potential as a platform immunotherapy.

Science Significance

Pelareorep, an intravenously delivered double-stranded RNA virus, works by transforming immunologically “cold” tumors into “hot” tumors, thereby activating both innate and adaptive immune responses. The updated safety analysis confirms that the most frequent side effects remain mild to moderate (Grade 1 and 2 fever, chills, fatigue, nausea, and diarrhea), while severe toxicities largely reflect the underlying chemotherapy regimens rather than pelareorep itself. Importantly, consistent tolerability across tumor types strengthens pelareorep’s candidacy as a combination therapy partner with chemotherapy and checkpoint inhibitors.

Regulatory Significance

With over 1,200 patients treated, pelareorep is now among the most clinically de-risked immunotherapies not yet approved for GI malignancies. The drug already holds FDA Fast Track designation in metastatic pancreatic and breast cancers, which accelerates regulatory review. The consistency of its safety profile, including in pancreatic, colorectal, and anal cancers, is expected to be a positive factor for regulators as Oncolytics moves toward registration-enabled clinical trials.

Business Significance

The updated dataset positions pelareorep as a competitive asset in the global immuno-oncology market, particularly in cancers with limited treatment options. Oncolytics emphasized that pelareorep’s strong safety record enhances its appeal to potential strategic partners, paving the way for co-development and commercialization deals. CEO Jared Kelly highlighted that the therapy is “one of the most de-risked immunotherapies not already approved in GI tumors,” a positioning that could boost investor confidence and accelerate business development discussions.

Patients’ Significance

For patients battling aggressive cancers like metastatic pancreatic and colorectal tumors, pelareorep offers hope beyond current treatment limitations. Its ability to enhance standard regimens such as modified FOLFIRINOX while maintaining manageable side effects could improve both treatment tolerability and survival outcomes. The intravenous administration route further makes it an accessible and scalable therapeutic option for cancer centers worldwide.

Policy Significance

The findings support broader policy discussions on advancing virus-based immunotherapies within oncology. Demonstrated safety across diverse patient populations strengthens the case for innovative trial designs, expanded regulatory frameworks for oncolytic virotherapies, and potential inclusion of such therapies in national cancer treatment guidelines. As global agencies push for faster adoption of precision oncology, pelareorep’s development trajectory could inform future policy decisions on immunotherapy access.

Transaction Highlights

So far, more than 1,200 patients have been treated with pelareorep, including 300+ with gastrointestinal cancers, confirming a consistent and manageable safety profile. Clinical trials span pancreatic, colorectal, and anal cancers, with combinations such as modified FOLFIRINOX showing promise. With Fast Track designation in metastatic pancreatic and breast cancer and strategic partnerships under active pursuit, pelareorep is positioned as one of the most clinically de-risked immunotherapies advancing toward registration studies.

Source: Oncolytics Biotech Press Release