PD-L1 blockade with avelumab: A new paradigm for treating Merkel cell carcinoma.

Merkel cell carcinoma (MCC) is a rare and aggressive neuroendocrine skin cancer. Until recently, no durable treatment options were available for patients with advanced disease. As an immunogenic cancer, MCC was hypothesized to be a candidate for PD-L1/PD-1 targeted therapy. On March 23, 2017 the US Food and Drug Administration granted accelerated approval for avelumab, an anti-PD-L1 monoclonal antibody, for the treatment of metastatic MCC on the basis of the JAVELIN Merkel 200 trial. Here we examine the results and implications of this pivotal study, published in Lancet Oncology by Kaufman et al., as well as current developments in the use of immune-checkpoint therapies for treating patients with MCC.