Abstract IA004: Targeting clonal heterogeneity in treatment-refractory Glioblastoma with novel and empiric immunotherapies

Abstract Despite aggressive multimodal therapy, glioblastoma (GBM) remains the most common malignant primary brain tumor in adults. With the advent of therapies that revitalize the anti-tumor immune response, several immunotherapeutic modalities have been developed for the treatment of GBM. In this talk, we summarize recent clinical and pre-clinical efforts to develop immunotherapeutic and chimeric antigen receptor (CAR) T cell treatment strategies for GBM recurrence, including challenges in the form of fundamental mechanisms of therapy evasion by tumor cells, such as immense intratumoral heterogeneity, suppression of the tumor immune microenvironment, and low mutational burden. Insights from these advances and challenges have shaped our development of a translational research pipeline from initial target discovery, through target validation and exploration of mechanism, to building new biotherapeutics against novel cancer targets, and preclinical testing in our patient-derived animal models of treatment-resistant GBM. We have tracked GBM cell populations that undergo clonal evolution as a result of selective pressures exerted by standard treatments to identify the cellular composition of the recurrence, to allow us to determine the intracellular signaling pathways that drive GBM relapse. Ultimately, we will design rational combinations of therapeutics that can reignite the anti-tumor immune response, effectively and specifically target tumor cells, and reliably decrease tumor burden for GBM patients. Citation Format: Sheila K Singh. Targeting clonal heterogeneity in treatment-refractory Glioblastoma with novel and empiric immunotherapies abstract. In: Proceedings of the AACR Special Conference on Brain Cancer; 2023 Oct 19-22; Minneapolis, Minnesota. Philadelphia (PA): AACR; Cancer Res 2024;84 (5 Suppl₁): Abstract nr IA004.