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

August 18, 2026: Oncolytics Biotech (NASDAQ: ONCY) said the FDA provided written feedback supporting a potential pivotal Part B expansion of the ongoing REO 033 study of pelareorep in second-line RAS-mutant, microsatellite stable metastatic colorectal cancer. The company had asked whether REO 033 Part A could support a pivotal Part B and whether Part B could support accelerated approval using objective response rate/duration of response, with progression-free survival supporting full approval.

According to the company, FDA’s written responses aligned with the proposed registration path and suggested an End-of-Phase meeting to finalize key elements of the program. Oncolytics therefore plans to skip its scheduled Type D meeting and pursue an End-of-Phase meeting as the program advances.

REO 033 is a randomized trial of pelareorep plus FOLFIRI and bevacizumab versus FOLFIRI and bevacizumab alone. Part A is ongoing and enrolls 60 patients; initial Part A data will determine whether the company launches the pivotal Part B. Oncolytics said it plans to begin Part B start-up activities as soon as positive interim Part A data are available to minimize delay.

The release also notes pelareorep combination therapy has FDA Fast Track designation in this colorectal cancer population.