Oncorus, Inc. announced the nomination of its first Synthetic viral RNA (vRNA) immunotherapy clinical candidates, ONCR-021 and ONCR-788. Oncorus’ pioneering intravenous (IV)-administered approach involves encapsulating the genomes of RNA viruses known to kill cancer cells (i.e., oncolytic viruses, or OVs) in a lipid nanoparticle (or LNP), creating a Synthetic vRNA immunotherapy. ONCR-021 encodes an optimized strain of Coxsackievirus A21 (CVA21), and ONCR-788 encodes for a modified version of the Seneca Valley Virus (SVV). Both CVA21 and SVV have extensive clinical experience and favorable safety profiles when administered IV. Oncorus’ novel Synthetic vRNA approach holds the potential for IV-administration and avoids the challenge of neutralizing antibodies seen in previous approaches with IV-administered OVs. Oncorus plans to investigate its novel Synthetic vRNA immunotherapies in multiple histologies including cancers of the lung both as monotherapy and in combination with immune checkpoint inhibitors and other cancer treatments. LNP-encapsulated IV-administered vRNA to create a “living immunostimulatory drug” Developing IV-administered RNA medicines for cancer requires addressing two primary technological hurdles: first, getting adequate concentrations of the RNA-based drug candidate to all tumor cells, and second, limiting exposure to normal tissue throughout the body. OVs, through rapid, self-amplification of their genomes in permissive cells and their ability to infect nearby cancer cells, are a potential answer to the challenge of the suboptimal LNP delivery of cargo RNA to tumor cells. In addition, OVs are selected or engineered to replicate more robustly in cells with deficiencies in antiviral responses, as is the case for cancer cells. OVs’ selectivity for tumors ensures that their genomes, when delivered by LNP, are minimally or not at all replicating in healthy tissues, thus potentially providing a large therapeutic window for Oncorus’ Synthetic vRNA immunotherapy candidates. Furthermore, the immunogenic cell death triggered by OVs, and the release of tumor antigens in an inflamed tumor microenvironment, are expected to broadly stimulate the immune system in its fight against cancer. Oncorus plans to file an investigational new drug (IND) application for ONCR-021 in the first half of 2023 to enable clinical development for non-small cell lung cancer and other cancers such as hepatocellular carcinoma, clear cell renal cell carcinoma and melanoma, both as a single agent and in combination with immune checkpoint inhibitors. Following the IND filing for ONCR-021, Oncorus plans to file an IND for ONCR-788 to enable its development in small cell lung cancer, neuroendocrine prostate and other neuroendocrine cancers, both as a single agent and in combination with immune checkpoint inhibitors and other cancer treatments. In the process of developing ONCR-021 and ONCR-788, Oncorus also developed and optimized a proprietary LNP platform for delivery of large nucleic acids, with efficient endosomal escape. Oncorus will manufacture ONCR-021 and ONCR-788 at its 88,000 square foot process development and Good Manufacturing Practices (GMP) manufacturing facility in Andover, Mass. With the site buildout underway, Oncorus plans to initiate process development activities at the facility in the second half of 2021 and anticipates this facility will be operational for GMP manufacturing in first half of 2023.