Cancer immunotherapy has recently achieved a breakthrough status, however, it is not effective in all cancer types. Genetically engineered oncolytic viruses (OVs) with immunomodulators are promising new therapeutic modalities for cancer. CARG-2020 is an engineered trivalent oncolytic viral construct that specifically expresses three immune modulators that inhibit IL-17RA signaling and regulate PD-L1 expression by shRNAs, along with the cytokine IL-12 which activates multiple tumoricidal pathways. Previous work showed that intratumoral (i.t.) injection of CARG-2020 exhibits robust efficacy against established colorectal cancer (CRC). In this study, we report that systemic delivery of CARG-2020 via the intravenous (i.v.) route can successfully control CRC growth. To further expand the scope of CARG-2020 as a pan-cancer candidate, we also show that CARG-2020 works in two additional mouse models of melanoma and triple-negative breast cancer. Administration of CARG-2020 resulted in increased accumulation of CD8+ T lymphocytes in the tumors, and depletion of these T cells results in poor tumor regression mediated by CARG-2020. Overall, our study shows a broad-spectrum efficacy of CARG-2020 in solid tumors and demonstrates the potential of CARG-2020 to be developed as a clinical candidate for the treatment of multiple human cancers that are surgically accessible.