458 Automated manufacturing of autologous tumor-reactive T cells for immunotherapy of glioblastoma
Year: 2024
Type: conference-abstract
Abstract: Background Glioblastoma multiforme (GBM) is the most common primary brain tumor with median overall survival of approximately 15 months from diagnosis. GBM will inevitably relapse following standard-of-care, and therefore has a high unmet need for new therapeutic strategies. Due to the high degree of intra- and interpatient GBM tumor heterogeneity, we sought to develop a clinical strategy focused on the use of tumor-infiltrating lymphocytes (TILs) to treat GBM. TILs have been used for decades in solid tumors with a good safety profile and possess polyclonal anti-tumor reactivities, potentially addressing the GBM tumor heterogeneity. Methods Cellular components of the glioblastoma digests were studied by flow cytometry and infiltrating T cells were characterized by single-cell RNA sequencing. The clinical scale manufacturing process was based on the automated and closed CliniMACS Prodigy® Tumor-reactive T cell (TRT) Process. Within this process reactive T cells were enriched based on expression of CD137, and expanded in a two-week rapid expansion protocol (REP) to reach clinically relevant numbers. The anti-tumor activity (cytolysis and cytokine release) of TIL products were analyzed upon 20-hour and72-hour co-culture with autologous tumor cell lines. Results Our data from 47 glioblastoma tumors demonstrate high infiltration of immune (CD45 positive) cells within the tumor digests, which are dominated by myeloid populations, with variable contributions of microglia, monocyte-derived macrophages and mononuclear myeloid-derived suppressor cells. Clinically relevant amounts of TILs could also be found in the all of analyzed digests, characterized by high CD137 expression as well as good representations of Granzyme B and Granzyme K T cell subset signatures. We present a clinical scale automated workflow capable of generating highly pure TRT products represented by central and effector memory T cell phenotype. In coculture assays TILs lysed autologous tumor cells, and produced effector cytokines. Lastly, we observed significantly increased tumoricidal activity when TIL were enriched for CD137 and a loss of activity when CD137 was depleted prior to the initiation of the REP. Conclusions We provide a comprehensive analysis of primary GBM tumors and demonstrate the feasibility of automated and closed manufacturing of GBM-derived TRTs. These findings extend the applicability of TILs to poorly-infiltrated tumors and represent a novel therapeutic strategy for addressing the complex heterogeneity of primary brain malignancies and other solid tumors. Acknowledgements We cordially thank our clinical partners, Prof. Dr. Martin Glas and Dr. Teresa Schmidt from the University Hospital Essen, Prof. Dr. Ulrich Herrlinger, Dr. Matthias Schneider and Anna-Laura Potthoff from the University Hospital Bonn; Prof. Dr. Marcus Czabanka and Dr. Thomas Broggini from the University Hospital Frankfurt; without whom this work would be impossible. Ethics Approval All studies related to analyzing patient material were performed according to approved protocols (Ethic votum approval numbers 501/21 and 2022-1042).
Institution: Miltenyi Biotec (Germany)
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $2,490
OpenAlex ID: W4404064644