SAN DIEGO, July 13, 2026
Oncolytics Biotech announced a significant clinical and regulatory update for its REO 033 randomized trial evaluating pelareorep in combination with FOLFIRI and bevacizumab for the second-line treatment of patients with RAS-mutant, microsatellite stable (MSS) metastatic colorectal cancer. The company confirmed rapid trial activation across leading clinical sites and revealed plans for an FDA Type D meeting to discuss a potential registrational pathway through the addition of Part B to the ongoing study.
REO 033 Enrollment Accelerates Across Global Clinical Sites
The multi-part randomized REO 033 study builds on encouraging efficacy results observed in the earlier REO 022 trial, where pelareorep exceeded historical standard-of-care benchmarks across progression-free survival, overall survival, duration of response, and objective response rate. Approximately half of the planned clinical sites are expected to be active by the end of July 2026, with more than 20 patients already pre-identified across participating centers. The remaining sites are anticipated to open by the end of August, supporting accelerated enrollment throughout the second half of 2026.
FDA Type D Meeting to Define Registrational Development Strategy
Oncolytics plans to meet with the U.S. Food and Drug Administration (FDA) during the first half of August 2026 to discuss expanding REO 033 by adding Part B, a randomized registration-directed study designed to support both accelerated approval and traditional full approval. The proposed expansion would preserve the existing trial infrastructure while increasing enrollment and incorporating blinded independent central review, potentially eliminating the need for a separate registrational study and reducing overall development timelines.
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Initial Clinical Readout Expected by Year-End 2026
The company expects to report an initial tumor response update from patients enrolled in Part A of REO 033 by the end of 2026. Subject to FDA feedback, enrollment in the proposed registrational Part B is expected to begin during the first quarter of 2027. Pelareorep has already received FDA Fast Track designation for RAS-mutant MSS metastatic colorectal cancer, and Oncolytics believes the ongoing clinical program positions the investigational immunotherapy as a promising potential treatment option in an area with significant unmet medical need.
Source: Oncolytics Biotech press release
