Complete regression of cutaneous metastases with systemic immune response in a patient with triple negative breast cancer receiving p53MVA vaccine with pembrolizumab.

A heavily pretreated patient with triple negative breast cancer distinguished by cutaneous metastases received p53MVA vaccine in combination with pembrolizumab. Her cutaneous metastases regressed and after 2 cycles of therapy, a skin biopsy showed a complete pathological response. Systemic response was confirmed with restaging CT and bone scans. Activation of p53-specific T cell responses and elevation of multiple immune response genes in peripheral blood correlated with the rapid clinical response which lasted for 6 months after the initiation of combined therapy.