Abscopal effect when combining oncolytic adenovirus and checkpoint inhibitor in a humanized NOG mouse model of melanoma

Melanoma, an immunogenic tumor, is the first indication where oncolytic viruses are now becoming part of clinical practice. ONCOS‐102, a transgened adenovirus, has shown to act as a primer of relevant tumor targeting immune cells both in preclinical and clinical melanoma studies. Strategies to augment its effectiveness warrant investigation. Combination therapy of ONCOS‐102 with the checkpoint inhibitor (CPI) pembrolizumab was evaluated in a quasi‐human animal model, the humanized NOG mouse model. A dosing schedule of the combination, beginning the CPI concurrently with the oncolytic viral therapy and continuing the CPI treatment, appeared to induce an abscopal effect in untreated tumor lesions. Concurrent combination therapy with checkpoint inhibitors may improve the induction of antitumor immune responses of ONCOS‐102. Highlight The combinatory therapy of ONCOS‐102 and CPI, appeared to induce an abscopal effect in untreated tumor lesions. The data support the development of ONCOS‐102 with checkpoint inhibitors for the treatment of malignant cancer diseases.