Immunotherapy is an emerging therapeutic strategy with a promising clinical 
outcome in some solid tumors, particularly metastatic melanoma. One approach to 
immunotherapy is immune checkpoint inhibitors, such as blockage of CTLA-4 and 
PD-1/PD-L1. This special report aims to describe the state of clinical trials of 
tremelimumab in patients with unresectable malignant mesothelioma (MM) in 
particular with regard to the clinical efficacy, safety and tolerability. 
Criticism and perspective of this treatment are also discussed. Biological and 
clinical considerations rule out the use of tremelimumab as single agent for MM 
and, more generally, the use of immune checkpoint inhibitors for MM is still 
largely questionable and not supported by evidences.