Measles virus (MV)-mediated compared to systemic checkpoint blockade. 1 × 106 B16-CD20 cells were implanted subcutaneously into the flank of C57BL/6 mice. Mice (n = 10 per group) received four intratumoral (i.t.) injections and four intraperitoneal (i.p.) injections of carrier fluid and saline, respectively (mock), carrier fluid and checkpoint modulating antibody (aCTLA-4, aPD-L1), MV encoding aCTLA-4 or aPD-L1 and saline (MV-aCTLA-4, MV-aPD-L1) or control MV and checkpoint modulating antibody (MV + aCTLA-4, MV + aPD-L1). (a) Schematic depicting the treatment schedule. (b) Distribution of tumor volumes on day 14 after implantation and (c) Kaplan–Meier survival analysis for CTLA-4 blockade. (d) Distribution of tumor volumes on day 14 after implantation and (e) Kaplan–Meier survival analysis for PD-L1 blockade.