Malignant Mesothelioma Effusions Are Infiltrated by CD3+ T Cells Highly Expressing PD-L1 and the PD-L1+ Tumor Cells within These Effusions Are Susceptible to ADCC by the Anti-PD-L1 Antibody Avelumab

Most pleural as well as peritoneal mesotheliomas express PD-L1. Malignant effusions in this disease are characterized by the presence of tumor cells and CD3-positive T cells that highly express PD-L1. In addition, mesothelioma tumor cells are susceptible to ADCC by the anti-PD-L1 antibody avelumab.