Oncolytics Biotech Inc. (Nasdaq: ONCY) announced on September 28, 2026, that it has activated substantially all planned clinical sites for its REO 033 study. The company reported that multiple patients are currently enrolled in the randomized trial evaluating pelareorep in combination with chemotherapy for metastatic colorectal cancer.
REO 033 is a randomized, controlled study designed to evaluate pelareorep in combination with folinic acid, fluorouracil, irinotecan, and bevacizumab versus the standard-of-care regimen of FOLFIRI and bevacizumab. The study targets patients with second-line RAS-mutant, microsatellite-stable (MSS) metastatic colorectal cancer. Part A of the study is expected to enroll approximately 60 patients randomized between the two treatment arms. The primary endpoint for Part A is the objective response rate (ORR), with progression-free survival (PFS), overall survival (OS), safety, and biomarker analyses serving as additional endpoints.
The company stated that, given the current pace of enrollment, it expects to have sufficient data from Part A to provide an interim clinical update by the end of 2026. This data is expected to be based on the number of evaluable patients enrolled by the end of October.
Oncolytics highlighted that REO 033 was designed to prospectively evaluate efficacy signals observed in the REO 022 study. In REO 022, the combination of pelareorep with FOLFIRI and bevacizumab demonstrated an objective response rate of 33%, a median progression-free survival of 16.6 months, and a median overall survival of 27.0 months, compared to historical benchmarks.
The company also noted that it recently aligned with the U.S. Food and Drug Administration (FDA) on a potential regulatory strategy. Under this proposed strategy, Part B of the study could support a potential accelerated approval submission based on objective response rate, with progression-free survival serving as the basis for potential full approval. The company expects data from Part A to inform the final size and execution of the potential pivotal Part B expansion.
