Oncolytics Biotech Inc. Accelerates REO 033 Enrollment for Pelareorep Study
News related to:Oncolytics Biotech Inc · 3 min read
SAN DIEGO, Sept. 28, 2026 /CourierPR/ -- Oncolytics Biotech Inc. has reported significant progress in its clinical trial REO 033, which is evaluating pelareorep, an investigational immunotherapy, in second-line RAS-mutant, microsatellite-stable metastatic colorectal cancer (mCRC). The company has activated nearly all planned clinical sites for Part A of REO 033, with multiple patients currently enrolled in the study. This activation process is expected to allow the company to generate randomized clinical data by year-end 2026, based on the number of evaluable patients enrolled by the end of October.
The FDA has aligned with Oncolytics Biotech Inc. on a potential regulatory strategy for a pivotal Part B expansion of REO 033, which could support a potential accelerated approval based on objective response rate. The pivotal Part B expansion would build directly upon the ongoing randomized REO 033 study. This regulatory strategy is expected to provide a path to accelerated approval based on objective response rate and full approval based on progression-free survival.
Oncolytics Biotech Inc. is focusing on accelerating enrollment and generating randomized clinical data to evaluate the contribution of pelareorep to the current standard-of-care regimen. Pelareorep is an intravenously delivered, systemically active investigational immunotherapy that selectively replicates in tumor cells while activating both innate and adaptive anti-tumor immune responses. It has been administered to over 1,200 patients in clinical studies, demonstrating its potential to enhance the activity of checkpoint inhibitors and other anti-cancer therapies across multiple solid tumor types.
The REO 033 study is a randomized controlled trial evaluating pelareorep in combination with folinic acid, fluorouracil, and irinotecan (FOLFIRI) and bevacizumab versus FOLFIRI and bevacizumab in patients with second-line RAS-mutant microsatellite-stable metastatic colorectal cancer (mCRC). The primary endpoint of the study is the objective response rate (ORR), with progression-free survival (PFS), overall survival (OS), safety, and biomarker analyses as additional endpoints.
Oncolytics Biotech Inc. has previously observed encouraging results in its REO 022 clinical data, which showed a combination of pelareorep with FOLFIRI and bevacizumab demonstrated encouraging ORR, PFS, and OS compared with historical second-line benchmarks. The REO 033 study is designed to prospectively evaluate the efficacy signals previously observed in REO 022 in a randomized setting.
Pelareorep has a dual mechanism of action, selectively replicating in tumor cells while activating both innate and adaptive anti-tumor immune responses, including the upregulation of key inflammatory cytokines resulting in the formation of tertiary lymphoid structures and the expansion of tumor-infiltrating lymphocytes. This mechanism of action has been observed in multiple first-line pancreatic cancer studies, two randomized Phase 2 studies in metastatic breast cancer, and early-phase studies in anal and colorectal cancer.
The FDA has granted accelerated approval to adagrasib with cetuximab for KRAS G12C-mutated colorectal cancer, a development that underscores the clinical promise of pelareorep in anal, colorectal, pancreatic, and other gastrointestinal cancers. Oncolytics Biotech Inc. is actively pursuing strategic partnerships to accelerate development and maximize commercial impact.
Oncolytics Biotech Inc. is a clinical-stage biotechnology company developing pelareorep, an investigational intravenously delivered double-stranded RNA immunotherapeutic agent. Pelareorep has demonstrated encouraging results in multiple first-line pancreatic cancer studies, two randomized Phase 2 studies in metastatic breast cancer, and early-phase studies in anal and colorectal cancer. It is designed to induce anti-cancer immune responses by converting immunologically inactive tumors to active through the activation of innate and adaptive immune responses.
The company is advancing pelareorep in combination with chemotherapy and/or checkpoint inhibitors in metastatic gastrointestinal cancers, where pelareorep has received Fast Track designation from the FDA for colorectal, anal, and pancreatic cancer. Oncolytics Biotech Inc. is actively pursuing strategic partnerships to accelerate development and maximize commercial impact.