Herein, by exploring the antitumor activity of a novel oncolytic adenovirus AdV-D24-ICOSL-CD40L in combination with anti PD-1 in in vitro and in vivo in immunocompetent mouse model engrafted with murine melanoma cells, we demonstrated that a therapy with OVs expressing potent immune modulators can be an effective strategy to drive the systemic efficacy of an immune checkpoint blockade. This evidence concerns the gene ICOSLG and melanoma.