Abstract 4748: Therapy model for advanced intracerebral B16 mouse melanoma using radiosurgery combined with immunotherapy.

Abstract

Abstract A reproducible therapy model for advanced intracerebral B16 melanoma is reported. Implanted tumors (D0), suppressed by a single 15 Gy radiosurgical dose of 100 kVp X-rays (D8) were further suppressed by a single ip injection of a Treg depleting Mab given two days prior to the initiation (D9) of four weekly then eight bi-monthly sc injections of GMCSF-transfected, mitotically disabled B16 cells. The results of seven independent experiments were similar to the combined result: the Median (Days) [SD/Total N] of survival went from 15[1.09/62] (No Treatment Control) to 35.8[8.8/58] (Radiosurgery-Only) to 52.5[13.5/57] (Radiosurgery Plus Immunotherapy); Radiosurgery-Only and Radiosurgery Plus Immunotherapy groups were highly distinct from Controls as well as from one another (p<0.0001). Within two weeks after immunization, tumors in mice receiving Radiosurgery Plus Immunotherapy were significantly smaller than tumors in mice treated only with Radiosurgery. Splenocytes and lymph node cells from immunized mice showed increased interferon Y production when cultured with syngenic tumor cells. We hypothesize that our model will be useful for the development and testing of novel combination therapies for brain tumors. Citation Format: Henry M. Smilowitz, Dan Sasso, Edward W. Lee, Peggy Micca, Gyuhyeong Goh, F Avrahamn Dilmanian. Therapy model for advanced intracerebral B16 mouse melanoma using radiosurgery combined with immunotherapy. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4748. doi:10.1158/1538-7445.AM2013-4748