A Study of Anti-CTLA-4 Antibody in Patients With Advanced Synovial Sarcoma

Approximately 750-900 people in the United States each year develop synovial sarcoma, a rare form of cancer of connective tissue. This tumor frequently metastasizes to other parts of the body such as the lungs. Chemotherapy can sometimes decrease the size of the recurrent tumors, but these results are usually only temporary, and the tumors grow again. We are trying to exploit some of the proteins made by synovial sarcoma (cancer-germ cell or cancer-testis antigens) as targets for the immune system. Specifically, we are investigating if immune-based therapy with anti-CTLA-4 antibody once every 3 weeks for three treatments will activate the immune system enough to attack recurrent synovial sarcoma. In this study the tumor itself serves as the "vaccine" or source of protein, as we try to activate tumor-fighting T cells with the anti-CTLA-4. Anti-CTLA-4 takes the brakes off the immune system to allow otherwise hidden immune responses to become more active. In so doing, there could be other side effects, such as immune system attacks against the normal organs of the body. We will follow both the anti-tumor immune responses with frequent blood tests and follow and treat side effects people develop on this study to determine if anti-CTLA-4 is worth pursuing in a larger number of patients with synovial sarcoma or other sarcomas.