Immunotherapy in Merkel cell carcinoma: role of Avelumab.

Merkel cell carcinoma (MCC), a rare skin cancer, is associated with high mortality, especially in a metastatic setting. Though conventional chemotherapy with platinum and etoposide has had high response rates, many of the patients have had early relapse without any effective therapy thereafter. Recently, immune check point inhibitors have shown very good durable responses, leading to the approval of a programmed death-ligand 1 inhibitor Avelumab for these patients. We briefly review the epidemiology and immune basis of the pathogenesis of MCC, which therefore explains the excellent response to check point inhibitors, and throw light on future directions of immunotherapy for this cancer.