Oncolytic Viruses (OV) selectively replicate in and lyse tumor cells and provide stimulation to the immune system. This represents a promising therapeutic option for cancer patients that do not respond well to treatment with immune checkpoint inhibitors. Myxoma virus (MYXV) is a member of the Poxviridae family of double stranded DNA viruses. The natural host of MYXV is a subset of lagomorphs, but MYXV can infect cancer cell lines of humans and other species. The genome of MYXV is relatively large and is amenable to engineering for expression of transgenes making it an excellent oncolytic virus for introduction of immunomodulatory proteins. The current work describes the oncolytic activity, transgene production capability, in vivo activity and immunomodulatory mechanism of actions following intratumoral and intravenous administration of armed myxoma viruses in murine cancer models. Additional combination therapy with clinically relevant immune checkpoint inhibitors is demonstrated.

Citation Format: Lina S. Franco, Lino E. Torres-Dominguez, Joseph Mamola, Ana L. de Matos, Mario Abrantes, Benjamin S. Walker, Zachary Tacner, Cassandra Kien, Natalie M. Elliott, Grant McFadden, Leslie L. Sharp. Armed Myxoma virus demonstrates efficacy in syngeneic tumor models alone and in combination with immune checkpoint inhibitors [abstract]. In: Abstracts: AACR Virtual Special Conference: Tumor Immunology and Immunotherapy; 2020 Oct 19-20. Philadelphia (PA): AACR; Cancer Immunol Res 2021;9(2 Suppl):Abstract nr PO091.