Abstract 1921: Armed oncolytic myxoma virus demonstrates efficacy in syngeneic tumor models alone and in combination with immune checkpoint inhibitors

Abstract

Abstract Oncolytic viruses (OV) selectively replicate in and lyse tumor cells and provide stimulation to the immune system, representing a promising therapeutic option in development to treat cancers that do not respond well to treatment with immune checkpoint inhibitors. Myxoma virus (MYXV) is a member of the Pox family of double stranded DNA viruses. The natural host of MYXV is a subset of rabbits and hares, 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. Oncolytic activity and transgene production capability were examined in multiple mouse cancer cell lines. In vivo efficacy following intratumoral and intravenous administration of armed myxoma virus, both alone and with immune checkpoint inhibitors is demonstrated. Immunomodulatory mechanisms of actions are investigated. Multi-armed myxoma represents a novel, engineerable, oncolytic virus with preclinical characteristics that warrant further investigation as an immunomodulatory cancer therapeutic. Citation Format: Lina S. Franco, Joseph Mamola, Wazir Abdullahi, Ana de Matos, Mario Abrantes, Benjamin S. Walker, Zachary Tacner, Nicole Grigaitis, Cassandra Kien, Grant McFadden, Leslie L. Sharp. Armed oncolytic myxoma virus demonstrates efficacy in syngeneic tumor models alone and in combination with immune checkpoint inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1921.