Abstract A022: Novel nanoparticle delivery of toll like receptor agonists alters the tumor immune landscape and improves response to standard of care therapy in preclinical PDAC models

Abstract

Abstract The tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) is becoming an increasingly complex system, driven by the interactions between multiple different cell types. These drivers of cancer progression can suppress local immune responses, promote resistance to therapies, and reinforce a pro-tumorigenic TME. Despite advances in other tumor types with immune checkpoint blockade, minimal progress has been made in the treatment of PDAC with immunotherapies targeted at adaptive responses. As such, with a majority of the TME being made up of innate immune cells being skewed towards immunosuppressive phenotypes, there remains an underutilized immunologic target. Of the potential subset of targets, toll like receptors (TLR) have garnered significant interest given the key role they have in controlling the innate immune response in a number of different immune cells. On their own, agonists of these family of receptors lack efficacy, either through poor tumor penetration, lack of target specificity or toxicity. To address this unmet need, we have developed a nano-delivery approach for TLR agonists for target immune cell uptake. Thus far, we have established two conjugates, a protein-based nanoparticle termed FN-TLR7 for the delivery of a CL307-based conjugate and a DNA nanoparticle termed CAGE-TLR9 for the delivery of a CpG-based agonist. We have found that these conjugates can activate target immune cells within the TME via an advantageous pharmacokinetic profile which significantly reduces nonspecific toxicities compared to free agonists. When paired with the current standard of care options in PDAC, we see significant improvements in tumor control. The implications of nano-delivery of TLR agonists for treating PDAC tumors will be discussed. Citation Format: Nathan Beals, Anthony Sorrentino, Dafna Bar-Sagi. Novel nanoparticle delivery of toll like receptor agonists alters the tumor immune landscape and improves response to standard of care therapy in preclinical PDAC models [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr A022.