The Prophage therapeutic platform generates an individualized therapeutic cancer vaccine for each patient. The vaccine for a patient is generated by isolating heat-shock proteins (HSPs) from the patient's individual tumor. Tumor HSPs are complexed to the milieu of material in the tumor, such as mutation neo-antigens. We use NGS, bioinformatics, computational immunology, and immuno-monitoring to explore the ‘omics space of GBM tumors and blood from patients treated with Prophage. We find between 104 and 214 non-synonymous mutations per tumor, including mutations in BRCA1 and EGFR, such as EGFRvIII, and large DNA copy number variations. Integrating patient HLA types, we predict mutation immunogenicity and prioritize mutations as neo-antigens. We correlate neo-antigens to clinical response. Using longitudinal blood samples taken pre- and post-vaccination, we explore both spontaneous and vaccine-induced immunogenicity to neo-antigens. Across the tumors, there are no neo-antigens in common, underscoring the need for individualized vaccination.

Citation Format: John Castle, Dan Levey, Elise Drouin, Nicholas Wilson, Steven Schoenfeld, Orin Bloch, Jennifer Buell. Exploring neo-antigens and immunological response in GBM patients after individualized Prophage vaccination. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A109.