Mesothelioma is a cancer of the peritoneum (lining of the abdomen) or pleura (lining of the lungs). The purpose of this study is to assess the safety and effectiveness of an investigational drug called tremelimumab in patients with peritoneal or pleural mesothelioma when it is given as the second or third therapy. Patients will be randomly assigned to receive tremelimumab (two-thirds of the patients) or a placebo (the remaining third); each will be given intravenously (by vein).
Tremelimumab is an antibody that blocks cytotoxic T lymphocyte antigen 4 (CTLA4), a protein found on cells of the immune system. CTLA4 puts the brakes on the immune response and may prevent immune cells from attacking cancer cells. Tremelimumab prevents this from happening, potentially enhancing the immune response against the cancer. Stimulating the immune system could be a different way of killing cancer cells.