Avelumab: A Novel Anti-PD-L1 Agent in the Treatment of Merkel Cell Carcinoma and Urothelial Cell Carcinoma.

Long-term treatment in the setting of metastatic Merkel cell carcinoma (MCC) and urothelial carcinoma (UC) has shown that current first-line chemotherapeutic agents are losing effectiveness and that there are limited treatment options available outside of radiation therapy and surgical interventions. The use of immunotherapeutic agents such as monoclonal antibodies has been considered a promising alternative for cancers that progress despite treatment with radiation therapy, surgery, and/or chemotherapeutic agents. Cancer cells escape immune surveillance by interrupting immune checkpoint pathways, resulting in dysregulation of T-cell function and so preventing its antitumor effects.