pelareorep + retifanlimab

Pelareorep + retifanlimab is an investigational combination therapy being evaluated primarily for metastatic triple-negative breast cancer (TNBC). Pelareorep is a proprietary isolate of the unmodified, replication-competent reovirus type 3 Dearing (T3D), developed by Oncolytics Biotech. It acts as an intravenously delivered immuno-oncolytic virus that selectively lyses tumor cells and induces both innate and adaptive immune responses. Pelareorep has been shown to upregulate PD-L1 expression in tumor and inflammatory cells while downregulating intra-tumoral regulatory T-cells, thereby priming the tumor microenvironment for enhanced response to immunotherapy. Retifanlimab is a humanized monoclonal antibody targeting programmed cell death protein 1 (PD-1), functioning as an immune checkpoint inhibitor. By blocking PD-1, it enables T-cell mediated anti-tumor activity. The rationale behind combining these agents is that pelareorep can convert "cold" tumors into "hot" ones—making them more susceptible to immune attack—while retifanlimab further unleashes the immune system against cancer cells. The combination is currently being studied in phase II clinical trials for patients with metastatic TNBC who have received one or two prior lines of chemotherapy[1][4][6]. The IRENE study evaluates safety and efficacy at multiple sites including Rutgers Cancer Institute of New Jersey and Ohio State University Comprehensive Cancer Center[4][6]. Retifanlimab has separate FDA approval under the brand name Zynyz for squamous cell carcinoma of the anal canal but not yet for breast cancer[5].

Other names

reovirus type 3 Dearing (T3D) + retifanlimaboncolytic virus pelareorep + anti-PD-1 checkpoint inhibitor retifanlimab