Pelareorep in combination with bevacizumab (Avastin) and leucovorin, fluorouracil, irinotecan (FOLFIRI) - (REO 033)

September 28, 2026: Oncolytics Biotech (NASDAQ: ONCY) said substantially all planned sites for Part A of REO 033 are activated and multiple patients are enrolled in the randomized study of pelareorep plus FOLFIRI/bevacizumab versus FOLFIRI/bevacizumab in second-line RAS-mutant, microsatellite-stable metastatic colorectal cancer. Part A is expected to enroll about 60 patients; the primary endpoint is objective response rate, with progression-free survival, overall survival, safety, and biomarkers as additional endpoints.

The company said it expects enough Part A data for an interim clinical update by year-end 2026, based on evaluable patients enrolled by the end of October.

Oncolytics also said it recently aligned with the FDA on a potential pivotal Part B expansion of REO 033. Under the proposed strategy, Part B could support accelerated approval based on objective response rate, with progression-free survival as the basis for potential full approval.

The company said REO 033 was designed to prospectively test signals seen in the non-randomized REO 022 study, where pelareorep plus FOLFIRI/bevacizumab showed ORR of 33%, median PFS of 16.6 months, median OS of 27.0 months, and median duration of response of 19.5 months, versus cited historical second-line benchmarks.