RNA Lipid Particles Targeting Pediatric Recurrent Intracranial Malignancies and Other systEmic Solid Tumors

The Investigators have demonstrated in preclinical studies that RNA liposomes activate APCs, induce antigen-specific T cell immunity, and can supplant DCs in a cell therapy model for HGG and have shown feasibility and activity of this approach in preclinical models and in canine patients with a spontaneous malignant glioma. In one arm of this study, we will investigate the safety and immunologic activity of RNA-LP vaccines in pediatric patients with recurrent pHGG.

The investigators have also shown that intravenous administration of tumor mRNA loaded lipid particles (LPs) localizes primarily to lung, transfect antigen presenting cells (APCs) and lead to an activated T cell response for induction of anti-tumor immunity. In contrast to other formulations, RNA-LPs recruit multiple arms of the immune system (i.e. innate/adaptive), and remodel the systemic/intratumoral immune milieu, which remain potent barriers for vaccine, cellular, and checkpoint inhibiting immunotherapies. After only a single RNA-LP vaccine, the bulk of systemic and intratumoral dendritic cells (DCs) in mice display an activated phenotype; these activated DCs (harvested from tumors) expand antigen specific T cell immunity. In immunologically resistant pulmonary osteosacroma murine tumor models (i.e. K7M2), RNA-LPs induce robust anti-tumor efficacy in settings where immune checkpoint inhibitors (i.e. anti-PD-L1 therapy) do not confer therapeutic benefit. The investigators have already demonstrated safety of RNA-LPs in acute/chronic murine toxicity studies, and in client-owned canine trial.

In this study, we will investigate the manufacturing feasibility, safety and immunologic activity of RNA-LP vaccine in patients with recurrent pulmonary or unresectable osteosarcoma and recurrent pHGG.