Abstract 2839: NK cell response and tumor debulking are associated to prolonged survival in recurrent glioblastoma treated by dendritic cells loaded with autologous tumor lysate.

Abstract

Abstract Recurrent glioblastoma (GB) are highly aggressive tumors allowing 6-8 month survival. Here we evaluated the possible benefits of immunotherapy with mature dendritic cells (DC) loaded with autologous tumor lysate in 15 patients with recurrent GB. After a median follow-up of 8 months median progression free survival (PFS) was 4.4 months and median overall survival (OS) 8.0 months. Patients with small tumors at first vaccination (< 20 cc; n = 8) had significantly longer PFS and OS than others: 6.0 vs 3.0 months (p = 0.01) and 16.5 vs 7.0 months (p = 0.003), respectively. Patients were analysed for CD8+ T cells, CD56+ NK cells and other relevant immunological parameters in peripheral blood before and after immunization, defining a vaccination/baseline ratio (V/B ratio). Increased V/B ratio of NK but not CD8+ T cells was significantly associated to longer PFS and OS. Patients showing NK cell responses had higher levels of IFN-γ and E4BP4, the NK cell transcription factor. Furthermore, NK V/B ratio was inversely correlated with TGF-β2 and VEGF V/B ratio. The results suggest that tumor-loaded DC may increase survival of recurrent GB after effective tumor debulking and emphasize the role of NK cell responses in this therapeutic setting. Citation Format: Serena Pellegatta, Marica Eoli, Simona Frigerio, Carlo Antozzi, Maria Grazia Bruzzone, Gabriele Cantini, Sara Nava, Elena Anghileri, Lucia Cuppini, Valeria Cuccarini, Emilio Ciusani, Marta Dossena, Bianca Pollo, Renato Mantegazza, Eugenio A. Parati, Gaetano Finocchiaro. NK cell response and tumor debulking are associated to prolonged survival in recurrent glioblastoma treated by dendritic cells loaded with autologous tumor lysate. [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 2839. doi:10.1158/1538-7445.AM2013-2839 Note: This abstract was not presented at the AACR Annual Meeting 2013 because the presenter was unable to attend.