Pembrolizumab-Induced Vitiligo in Esophageal Squamous Cell Carcinoma Patient With Durable Complete Response

Immune checkpoint inhibitors have emerged as a valuable therapeutic strategy in cancer treatment. Pembrolizumab is an inhibitor of programmed cell death protein 1 (PD-1) and its ligands 1 (PD-L1) and 2 (PD-L2). Disrupting the interaction between PD-L1 expressed on the cancer cell and PD-1 transmembrane protein on immune cells results in reactivation of T cell-mediated cellular immunity. This immune modulation has increased the risk of autoimmune adverse events, which can affect any organ system. Here, we present a case of delayed immune checkpoint inhibitor-induced vitiligo in a 74-year-old female with recurrent metastatic esophageal carcinoma who remains in remission more than five years after initiation of pembrolizumab.