Dual Immunostimulatory Pathway Agonism through a Synthetic Nanocarrier Triggers Robust Anti‐Tumor Immunity in Murine Glioblastoma

Abstract

with chemoradiation, Food and Drug Administration (FDA)-approved treatments such as intracavitary chemotherapy wafers, bevacizumab, and alternating electrical fields [1] with median survival times of approximately 15 months from diagnosis. [2] Numerous promising therapeutic modalities (targeted kinase inhibitors, anti-angiogenic treatments, immunotherapies) have been tested in advanced clinical trials without lasting success.There has been a resurgence of interest in therapeutic modalities that stimulate the immune system against tumor cells. However, immune checkpoint inhibitors (ICI) have generally not been as successful against GBM as they have been for other cancers. [3] Although there is still interest in ICI therapy alone in a neo-adjuvant setting, [4] the neuro-oncology community has been trying to explain its limited efficacy. One accepted explanation is that the GBM microenvironment is dominated by profound myeloid immunosuppression and continuous changes and adaptation to therapies. [5][6][7] This immunosuppression inhibits effective immune surveillance by altering the ability of anti-tumor effector immune cells (T cells, macrophages (MF), natural killer (NK) cells) to infiltrate and destroy the GBM.Myeloid cells are abundant, create a highly immunosuppressive environment in glioblastoma (GBM), and thus contribute to poor immunotherapy responses. Based on the hypothesis that small molecules can be used to stimulate myeloid cells to elicit anti-tumor effector functions, a synthetic nanoparticle approach is developed to deliver dual NF-kB pathway-inducing agents into these cells via systemic administration. Synthetic, cyclodextrinadjuvant nanoconstructs (CANDI) with high affinity for tumor-associated myeloid cells are dually loaded with a TLR7 and 8 (Toll-like receptor, 7 and 8) agonist (R848) and a cIAP (cellular inhibitor of apoptosis protein) inhibitor (LCL-161) to dually activate these myeloid cells. Here CANDI is shown to: i) readily enter the GBM tumor microenvironment (TME) and accumulate at high concentrations, ii) is taken up by tumor-associated myeloid cells, iii) potently synergize payloads compared to monotherapy, iv) activate myeloid cells, v) fosters a "hot" TME with high levels of T effector cells, and vi) controls the growth of murine GBM as mono-and combination therapies with anti-PD1. Multi-pathway targeted myeloid stimulation via the CANDI platform can efficiently drive anti-tumor immunity in GBM.

Perfusion Window Chambers Enable Interventional Analyses of Tumor Microenvironments

“…CANDI is a biocompatible succinyl‐cyclodextrin polymeric drug carrier with affinity for tumor‐associated macrophages. [ 38,40 ] It contains small molecule drugs such as TLR7/8 agonist (R848), cIAP inhibitor (Lcl‐161), and a JAK1 inhibitor (ruxolitinib). In vitro, the drug induces IL‐12 via the canonical and noncanonical NFkB pathways and by inhibiting IL4 signaling.…”

“…CANDI Experiments: The synthesis of cyclodextrin nanoparticles (CANDI) was further developed from a previously reported method. [38,40] Fluorescent CANDI was prepared by attaching AF647 succinimidyl ester (ThermoFisher, 2 mg mL −1 in DMSO). The labeled nanoparticle was purified by buffer exchange into water against 10 kDa MWCO centrifugal filters (Amicon; 10 000 rcf for 5 min; 300 μL water per wash, 3-4×).…”

“…We have been interested in developing myeloid cell therapeutics that could be used to enhance and jumpstart a more effective immune response in tumors. [38][39][40] In order to achieve this goal, it is frequently necessary to image different cellular targets and processes, which can be facilitated by the PWC setup. CANDI is a biocompatible succinyl-cyclodextrin polymeric drug carrier with affinity for tumor-associated macrophages.…”

The prognostic significance of genes involved in glycolysis, immunity, and epithelial-to-mesenchymal transition in glioblastoma

“…The PFI group with the highest risk score was shown to have substantial connections with genes related to the immune response, regulation of in ammatory response, collagen-containing extracellular matrix, and signaling pathways regulating pluripotency of stem cells. All of these factors have a strong relationship with the antitumor response, the spread of tumor metastases, the development of drug resistance, and the progression of tumors [42][43][44] .…”

Hybrid LNP Prime Dendritic Cells for Nucleotide Delivery

“…Recent work in tumor‐associated myeloid cells has shown that dual NFkB pathway manipulation is effective and improves tumor control. [ 8 ] This prior work used a 37 nm carbohydrate platform (CANDI) to deliver multiple small molecule immune modulators to tumor‐associated macrophages and a lesser degree to DCs. Here we reasoned that an analogous strategy could be developed for dendritic cell‐targeted vaccines but would have to be based on lipid nanoparticles (LNP) to improve dsRNA delivery.…”