Oncolytics Biotech has launched a new metastatic colorectal cancer study to evaluate its investigational immunotherapy pelareorep in combination with standard treatments. The Phase 2 trial aims to assess whether the therapy can improve outcomes for patients with KRAS-mutant microsatellite-stable disease.
Metastatic colorectal cancer study begins enrolment
Oncolytics Biotech announced the initiation of the REO 033 clinical trial, a randomised Phase 2 metastatic colorectal cancer study. The trial will compare standard treatment using bevacizumab and FOLFIRI chemotherapy with an experimental regimen that adds pelareorep.
The study will enrol 60 patients with second-line RAS-mutated microsatellite-stable metastatic colorectal cancer who have previously received platinum-based chemotherapy. The primary endpoint is objective response rate, with progression-free survival, overall survival, safety and biomarker analysis included as secondary endpoints.
How immunotherapy is being explored in colorectal cancer
Immunotherapy has become an important area of research in oncology. In colorectal cancer, investigators are exploring therapies that stimulate the immune system to recognise and attack tumour cells.
Pelareorep is an investigational double-stranded RNA immunotherapeutic designed to activate innate and adaptive immune responses. The approach aims to convert immunologically “cold” tumours into more immune-responsive environments.
Previous results and regulatory recognition
Earlier clinical research combining pelareorep with bevacizumab and FOLFIRI demonstrated encouraging outcomes in patients with metastatic colorectal cancer. In the REO 022 study, the combination therapy showed a median overall survival of 27 months and progression-free survival of 16.6 months.
These results compare with approximately 11.2 months overall survival and 5.7 months progression-free survival typically observed with standard treatment alone in similar patient populations.
Fast Track designation supports continued development
The treatment combination recently received Fast Track designation from the U.S. Food and Drug Administration for second-line KRAS-mutant microsatellite-stable metastatic colorectal cancer.
The REO 033 metastatic colorectal cancer study will be led by Sanjay Goel, Professor of Medicine at Rutgers Cancer Institute of New Jersey. Preliminary data from the trial are expected by the end of 2026.
More developments in oncology drug development can be found in the Pharmaceuticals section of Life Sciences Global News.

