Therapeutic efficacy of PD1/PDL1 blockade in B16 melanoma is greatly enhanced by immunization with dendritic cell-targeting lentiviral vector and protein vaccine.

While immune checkpoint inhibition is rapidly becoming standard of care in many solid tumors, immune checkpoint inhibitors (ICIs) fail to induce clinical responses in many patients, presumably due to insufficient numbers of tumor-specific T cells in the tumor milieu. To this end, immunization protocols using viral vectors expressing tumor-associated antigens are being explored to induce T cell responses that synergize with ICIs. However, the optimal combination of vaccine and immune checkpoint regimen remains undefined.