Treatment of murine transitional cell carcinoma with intralesional interleukin 2 and murine interferon gamma.

The antitumor effect of intralesionally administered recombinant interleukin-2, alone or in combination with recombinant interferon gamma was studied in murine transitional cell carcinoma, MBT2. In the initial prophylactic model treatment was started at day one at the site of tumor inoculation. Maximal and significant reduction in tumor volume occurred in groups receiving 4,000 units of recombinant interleukin 2 and 10(7) colony forming units Bacillus Calmette Guerin (p less than 0.00001 vs saline control). In the same experiment, a reduction in tumor incidence and increase in survival occurred in groups receiving 4,000 units of recombinant interleukin 2, 1,000 units of recombinant interleukin 2 plus 2,000 units of recombinant interferon gamma, as well as 10(7) colony forming units Bacillus Calmette Guerin relative to saline control (p less than 0.005). The dose-response effect of recombinant interleukin 2 alone was also tested in a model of an established transitional cell carcinoma. Intralesional injection treatments were initiated after tumors were palpable. Reduction in tumor volume was observed in the group receiving 8,000 units of recombinant interleukin 2 (p = 0.01 vs saline control), but no significant advantage in survival was noted.