Immunotherapy with neuraminidase-treated cells and bacillus Calmette-Guerin.

Experiments were designed to determine the effectiveness of active immunotherapy, both specific (neuraminidase-treated cells) and nonspecific [bacillus Calmette-Guerin (BCG) organisms] in the L1210-BDF1 tumor-host system. Tumor burden was minimized with chemotherapy (1,3-bis-(20chloroethyl)-1-nitrosourea) prior to immunotherapy. The effectiveness of immunotherapy was dependent on the amount of drug used to minimize tumor burden. An interval 36 hours between chemotherapy and immunotherapy produced the maximum number of survivors. A single immunization with 10(4) neuraminidase-treated cells was superior to other single or multiple immunizations. BCG was most effective when mice were given 393 X 10(5) organisms. Beneficial effects of immunotherapy were observed only when immunizations were given by an intraperitoneal route. All mice cured of tumor developed tumor-specific immunity. The highest levels of immunity were observed in mice given both neuraminidase-treated cells and BCG organisms after chemotherapy.