Conditions: Stage III Merkel Cell Carcinoma AJCC v8; Stage IIIB Merkel Cell Carcinoma AJCC v8; Stage IIIA Merkel Cell Carcinoma AJCC v8
Interventions: Drug: Avelumab; Other: Peripheral Blood Collection; Other: Placebo
Sponsors: University of Washington; EMD Serono
Active, not recruiting