IMMU-12. T-CELL THERAPIES DEMONSTRATE EFFICACY WITHOUT TOXICITY IN IMMUNOCOMPETENT MODELS OF BRAINSTEM TUMORS

Abstract Diffuse intrinsic pontine glioma (DIPG) is a pediatric brainstem tumor with a dismal prognosis and no curative treatments. Immunotherapy has been considered as a treatment for these tumors because of its ability to provide specific and sustained tumor killing. By nature, this approach is inflammatory and remains controversial due to the potential for catastrophic inflammatory toxicity in the brainstem. In order to address whether this approach should be considered as a clinical option, we characterized the efficacy/toxicity profile of transgenic and chimeric antigen receptor (CAR) T-cell therapies in the brainstem using immunocompetent, syngeneic mouse models. We first adoptively transferred naïve transgenic T-cells recognizing the model tumor antigens gp100 or ovalbumin to treat established aggressive, transplantable murine tumors in the brainstem. Encouragingly, this therapy significantly extended median survival (16 to 32 days; p