Abstract CT571: Plasma proteomic markers prognostic or predictive for survival of patients with newly diagnosed glioblastoma who were treated in a phase II trial with standard care and the addition of the novel patient-specific dendritic cell vaccine AV-GBM-1

Abstract

Abstract Standard aggressive therapy for primary newly diagnosed glioblastoma (GBM), which includes surgical resection followed by concurrent radiation therapy and temozolomide chemotherapy (RT/TMZ) and then maintenance TMZ, is associated with poor survival rates. Adding treatment with AV-GBM-1, a personal vaccine consisting of autologous dendritic cells (DC) pulsed with autologous tumor antigens (ATA) may improve survival. AV-GBM-1 is produced by incubating ATA with autologous DC. ATA are from a lysate of irradiated autologous GBM cells that were self-renewing in serum-free medium with factors that favor survival and proliferation of tumor initiating cells, i.e., stem cells and early progenitor cells. After recovery from RT/TMZ, GBM patients were injected subcutaneously with AV-GBM-1 admixed in granulocyte-macrophage colony-stimulating factor (GM-CSF) at weeks 1, 2, 3, 8, 12, 16, 20, and 24. This study examined changes in plasma proteomics before and after injections of AV-GBM-1. 57 patients were treated during November 2018 to October 2020. Median progression-free and overall survival were 10.3 and 16.0 months respectively. Plasma samples obtained at baseline (week-0), and just prior to the third injection (week-2) were cryopreserved and subsequently analyzed for 448 proteomic markers using quantitative, multiplex enzyme-linked immunosorbent assays (Raybiotech, Inc., Norcross, GA.). 54 patients had a baseline week-0 sample prior to the 1st vaccination; 50 had a week-2 sample just prior to the 3rd dose; 49 had paired samples for both time-points. The averages of paired samples were measured for all patients and for cohorts defined by median survival that were compared by 2-tail T-Tests. After two weekly injections there were significant (p<0.01) increases in thymus and activation-regulated chemokine (TARC, CCL17), chemerin, lipocalin-2 and angiopoietin, and decreases in thrombospondin-5, angiotensinogen, and beta-fibroblast growth factor. The changes in TARC are due to GM-CSF. 25 patients survived more than 15 months and 24 less than 15 months. Prognostic baseline markers associated with longer survival were higher CD14 (p=0.009), higher tissue-inhibitor of metalloproteinases (TIMP-1), and higher insulin growth factor binding proteins (IGFBP) 1 and 2 (p<0.02). The only markers that appeared predictive for survival (p<0.05) based on changes from baseline to week-2 were increased lipocalin-2, associated with longer survival (p=0.0369), and decreased brain-derived neurotrophic factor (BDNF) associated with shorter survival (p=0.0186). Because of the large number of analyses, these results are considered hypothesis generating and not definitive. Citation Format: Daniela A. Bota, David E. Piccioni, Christopher M. Duma, Renato V. LaRoca, Santosh Kesari, Mehrdad Abedi, Robert D. Aiken, Aleksandra J. Poole, Gabriel I. Nistor, Robert O. Dillman. Plasma proteomic markers prognostic or predictive for survival of patients with newly diagnosed glioblastoma who were treated in a phase II trial with standard care and the addition of the novel patient-specific dendritic cell vaccine AV-GBM-1 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT571.