IL-12-expressing highly immunogenic recombinant modified vaccinia virus Ankara reprograms tumor-infiltrating myeloid cells to overcome immune resistance

Novel strategies to reprogram tumor-infiltrating myeloid cells for cancer immunotherapy are urgently needed, given that the primary and acquired resistance to immune checkpoint blockade (ICB) therapy has hindered the overall success of immunotherapy. Modified vaccinia virus Ankara (MVA) is a highly attenuated, non-replicative vaccinia virus and an approved vaccine against smallpox and monkeypox. Here we report rational engineering of recombinant MVA, MQ833, by removing three immune suppressive genes, E5R, E3L, and WR199, from the MVA genome and inserting three transgenes encoding Flt3L, OX40L, and IL-12. Intratumoral (IT) delivery of MQ833 generates potent antitumor responses dependent on CD8+ T cells, neutrophils, and M1-like macrophages, the nucleic acid-sensing pathways mediated by MDA5/STING, and interferon feedback loop. IT MQ833 promotes the recruitment and activation of neutrophils and inflammatory monocytes into the injected tumors, depletion of M2-like macrophages, and expansion of M1-like macrophages, generating potent antitumor immunity against tumors resistant to ICB. ### Competing Interest Statement Memorial Sloan Kettering Cancer Center filed a patent application for the use of recombinant MVA as monotherapy or in combination with immune checkpoint blockade for solid tumors. L.D., J.D.W., T.M., N.Y. Y.W. G.M. are authors on the patent, which has been licensed to IMVAQ Therapeutics. L.D., J.D.W., T.M., W.Y., J.C. and N.Y. are co-founders of IMVAQ Therapeutics. T.M. is a consultant of Immunos Therapeutics and Pfizer. He has research support from Bristol Myers Squibb; Surface Oncology; Kyn Therapeutics; Infinity Pharmaceuticals, Inc.; Peregrine Pharmaceuticals, Inc.; Adaptive Biotechnologies; Leap Therapeutics, Inc.; and Aprea. He has patents on applications related to work on oncolytic viral therapy, alpha virus-based vaccine, neoantigen modeling, CD40, GITR, OX40, PD-1, and CTLA-4. J.D.W. is a consultant for Adaptive Biotech, Advaxis, Am-gen, Apricity, Array BioPharma, Ascentage Pharma, Astellas, Bayer, Beigene, Bristol Myers Squibb, Celgene, Chugai, Elucida, Eli Lilly, F Star, Genentech, Imvaq, Janssen, Kleo Pharma, Linnaeus, MedImmune, Merck, Neon Therapeutics, Ono, Polaris Pharma, Polynoma, Psioxus, Puretech, Recepta, Trieza, Sellas Life Sciences, Serametrix, Surface Oncology, and Syndax. Research support: Bristol Myers Squibb, Medimmune, Merck Pharmaceuticals, and Genentech. Equity: Potenza Therapeutics, Tizona Pharmaceuticals, Adaptive Biotechnologies, Elucida, Imvaq, Beigene, Trieza, and Linnaeus. Honorarium: Esanex. Patents: xenogeneic DNA vaccines, alphavirus replicon particles ex-pressing TRP2, MDSC assay, Newcastle disease viruses for cancer therapy, genomic signature to identify responders to ipilimumab in melanoma, engineered vaccinia viruses for cancer immunotherapy, anti-CD40 agonist mono-clonal antibody (mAb) fused to monophosphoryl lipid A (MPL) for cancer therapy, CAR T cells targeting differentiation antigens as means to treat cancer, anti-PD-1 antibody, anti-CTLA-4 antibodies, and anti-GITR antibodies and methods of use thereof.