Immunotherapy of ovarian carcinoma.An experimental model

The specificity of a tumor antigen of an experimental ovarian carcinoma was determined by immunofluorescence, cytotoxicity, and immunoelectro-phoresis using an absorbed heterologous tumor antiserum. Tumor controls and normal rabbit sera controls were compared to tumor antiserum-treated recipients. Tumor control animals died by the 36th day after tumor transplantation. Normal rabbit serum was shown to contain a natural antibody which prolonged survival. Treatment with unabsorbed tumor antiserum in vitro led to 100% survival; 24 hours after tumor transplantation 30–40% survival; 48 hours after tumor transplantation 50%; and when animals with advanced disease were treated from the 4th-8th day with daily injections this resulted in 30% long-term survivors. The intraperitoneal administration of tumor antiserum allows for direct binding with tumor cells without dilution in the circulation and at a reduced risk of nonspecific binding in critical organs and demonstrates the efficacy of serologic immunotherapy.