Neoantigen-based Personalized DNA Vaccine With Retifanlimab PD-1 Blockade Therapy in Patients With Newly Diagnosed, Unmethylated Glioblastoma

This is a single institution, open-label, multi-arm, phase I study assessing the safety and immunogenicity of a personalized neoantigen-based personalized DNA vaccine combined with PD-1 blockade therapy in subjects with newly diagnosed, MGMT promoter unmethylated glioblastoma (GBM). Immune checkpoint blockade, specifically those targeting the PD-1/PD-L1 pathways, has shown efficacy in multiple solid and hematologic malignancies. Furthermore, as has been demonstrated in metastatic melanoma, combining PD-1/PD-L1 blockade with other immune checkpoint inhibitors has shown improved objective response rates, though there is a significant increase in serious immune-related adverse events. As such, current trials are exploring different doses, administration schedules, and immune checkpoint agents. One alternative approach, however, is to introduce a tumor-directed therapy such as a personalized neoantigen vaccine combined with these immune modulating agents (i.e. immune checkpoint blocking antibodies) to maximize the tumor-specific response but minimize the toxicity associated with increasing non-specific systemic immune activation by generating a potent and focused neoantigen specific immune response. This study will test the hypothesis that a personalized neoantigen DNA vaccine in combination with concurrent administration of immune checkpoint blockade therapy will enhance the magnitude and breadth of neoantigen-specific T cell responses while maintaining an acceptable safety profile. The overall goal of this study is to identify the optimal vaccine plus adjuvant platform that can be tested in a subsequent phase II study to determine the efficacy of a personalized neoantigen vaccine approach in patients with GBM.