PDCD1 and melanoma: T-VEC combinations with checkpoint inhibitors show early promising results in melanoma.61,62 Of note, in a trial of T-VEC plus pembrolizumab, responses did not correlate with baseline CD8+ T cell infiltration or interferon-gamma expression, but objective responses were associated with post-treatment infiltration and expression, indicating that T-VEC may modify the microenvironment to enhance PD-1 response.63