Merkel cell carcinoma immunotherapy: key questions in the era of immune checkpoint blockade

<p>Merkel cell carcinoma (MCC) exemplifies the paradigm of immunogenic tumors that nonetheless develop sophisticated immune evasion mechanisms. This is in line with the observation that MCC exhibits remarkable susceptibility to immune checkpoint inhibitors (ICIs), with responses in approximately half of patients with advanced disease in the first-line setting. However, 40&ndash;50% of patients show primary ICI resistance, while 20&ndash;30% of patients…