BackgroundDiffuse midline glioma (DMG) is a universal fatal glial brain cancer in children. We tested our novel multilamellar mRNA lipid particle aggregate vaccine (RNA-LPA, IND19304—Sayour),1 a ...tumor-agnostic treatment platform that encapsulates tumor specific RNA and delivers the payload in a highly immunogenic fashion, as an approach to treating this currently incurable cancer.MethodsUsing the K2 DMG model,2 we implant H3K27M-expressing DMG cells into the 4th ventricle of P1-P3 neonatal C57BL/6 mice. RNA-LPA generated from predicated human H3K27M epitopes or total-tumor mRNA are administered intravenously beginning at day 35. We performed multiparameter 3D geospatial fluorescent microscopy to characterize mRNA transduction. Immunologic responses to treatment were evaluated by multiparameter flow cytometry, microscopy, and cytokine profiling.ResultsMice developed clinical neurological signs of disease by day 30–35. RNA-LPAs targeting human H3K27M epitopes were found to be immunogenic in wild-type mice. Intriguingly, nonspecific enhanced green fluorescent protein (eGFP)-RNA-LPAs resulted in statistically significant survival benefits compared to mice treated with empty LPs. However, tumor-specific RNA-LPAs (either H3K27M-specific or total tumor mRNA-derived) also enhanced survival and additionally resulted in a subset of mice with long-term survival. This survival benefit was observed despite the development of clinical hydrocephalus in mice treated with RNA-LPAs. 3D microscopy established that tumors demonstrated invasive disease and microvascular erosion in mice. We found that mRNA transduces fibroblastic reticular cells (FRCs) in the spleen and lymph nodes, prompting widespread immune activation. Treatment with RNA-LPA led to massive increases in production inflammatory cytokines (i.e. TNF-α) and chemokines (i.e. CCL2), which led to recruitment of the majority of circulating monocytes and lymphocytes to secondary lymphoid organs.ConclusionsRNA-LPAs extend survival in our highly aggressive DMG model, including curative outcomes in cohorts treated with either total tumor or H3K27M RNA-LPs. These data suggest that RNA-LPs are capable of stimulating host adaptive immune responses against established DIPG tumors. Signs of hydrocephalus in treated mice may indicate pseudoprogression due to immunologic response, yet mice were frequently able to survive this development. Future studies will further characterize the immunologic response in these mice and support expansion of our existing IND for a multi-institutional phase I clinical trial for children with DMG, who currently have no curative options.AcknowledgementsWe appreciate funding from the ChadTough Defeat DIPG Foundation and the DIPG/DMG Research Funding Alliance. John Ligon and Elias Sayour contributed equally and are co-senior authors.ReferencesMendez-Gomez H, DeVries A, Castillo P, Stover B, Qdaisat S, Von Roemling C, Ogando-Rivas E, Weidert F, McGuiness J, Zhang D, Chung MC, Li D, Zhao C, Marconi C, Campaneria Y, Chardon-Robles J, Grippin A, Karachi A, Thomas N, Huang J, Milner R, Sahay B, Sawyer WG, Ligon JA, Silver N, Simon E, Cleaver B, Wynne K, Hodik M, Molinaro A, Guan J, Kellish P, Doty A, Lee J-H, Carrera-Justiz S, Rahman M, Gatica S, Mueller S, Prados M, Ghiaseddin A, Mitchell DA, Sayour EJ. mRNA aggregates harness danger response for potent cancer immunotherapy. medRxiv. 2023:2023.03.12.23287108. doi: 10.1101/2023.03.12.23287108.Misuraca KL, Cordero FJ, Becher OJ. Pre-Clinical Models of Diffuse Intrinsic Pontine Glioma. Front Oncol. 2015;5:172. doi: 10.3389/fonc.2015.00172. PubMed PMID: 26258075; PMCID: PMC4513210.Ethics ApprovalWork approved under UF IACUC 202200000375
Abstract
BACKGROUND
High-grade gliomas are an aggressive subset of CNS tumors in need of novel treatment strategies. However, tumor heterogeneity, the immunosuppressive tumor microenvironment (TME) ...and the lack of immunogenic tumor specific targets have limited the translational power of many immunotherapies for high-grade gliomas. The promising application of mRNA vaccines has the potential to restore immunosurveillance through peripheral and intratumoral reprograming of the TME.
METHODS
Our lab has developed a lipid particle multilamellar aggregate (RNA-LPA) vaccine that encapsulates tumor specific RNA and delivers the payload to the immune system in a highly immunogenic fashion, similar to that of a virus. We sought to assess anti-tumor activity across preclinical murine models and investigate the mechanisms for response.
RESULTS
We demonstrated the immune activation potential of RNA-LPAs encoding for glioma associated antigens (i.e., pp65 and H3K27M) in preclinical murine models. We also showed activity of personalized RNA-LPA in canine and human studies (NCT04573140) for patients with high-grade gliomas. Exogenous RNA is recognized by pathogen recognition receptors (PRRs) which trigger a type I interferon (IFN) response and proinflammatory cytokine production. While most RNA based vaccines activate an innate immune response primarily through toll-like receptor 7 (TLR7), we reveal that RNA-LPAs activate the innate immune system through retinoic acid-inducible gene 1 protein (RIG-I). As a result of PRR signaling, the type I IFN and cytokine/chemokine response (IL-6, G-CSF, TNF-alpha, CXCL9, CXCL10, CCL2, CCL4) mediates massive recruitment of activated dendritic cell and activated T cell in lymphoreticular organs where antigen presenting cells and cytolytic T cell colocalize to initiate an adaptive immune response against glioma specific antigens.
CONCLUSION
RNA-LPAs are a novel platform immunotherapy that initiate anti-tumor immunity against malignant brain tumors through noncanonical activation of intracellular PRRs and widespread recruitment of peripheral blood mononuclear cells to sites of RNA-LPA localization.
Abstract
BACKGROUND
Glioblastoma immunotherapy trials remain limited by heterogeneity and the immunosuppressive tumor microenvironment (TME). To overcome these challenges, we developed a novel cancer ...immunotherapy that leverages use of mRNA lamellar aggregates (RNA-LPA) encoding for personalized glioblastoma antigens to simultaneously reprogram the GBM TME while inducing tumor specific immunity in the periphery.
METHODS
In a Phase I trial (PNOC020) with an embedded acceleration titration design (ATD) for patients with newly-diagnosed MGMT unmethylated glioblastoma, we sought to assess whether intravenous administration of RNA-LPAs encoding for pp65 mRNA (tumor associated antigen) mixed with personalized tumor mRNA (extracted and amplified from patient specific biopsies) could activate peripheral immunity while simultaneously reprogramming the GBM TME. All patients received surgical resection with adjuvant chemoradiation followed by escalating doses of RNA-LPA (0.625-1.5 µg/kg).
RESULTS
We have treated 3 patients on the ATD and one patient on the expanded Phase I trial. In all patients treated to date, RNA-LPAs elicited a rapid response (within hours) characterized by release of cytokines (IL-12, TNF-α, IFN-α), chemokines (CCL2, CCL4, CXCL9-10), increase in plasmacytoid dendritic cells and recruitment of peripheral blood mononuclear cells. Over time there was expansion of antigen specific T cells; T cell receptor (TCR) sequencing pre- and post-infusion demonstrated changes to the most prevalent clonotypes by ~10-20%. In the first subject treated on the expanded phase I trial, we observed significant immunologic response after the fourth vaccine, including 20-fold increase in IFN-γ inducible protein-10. One month after vaccine administration, there was marked increase in the enhancing areas on MRI, which on biopsy demonstrated no viable tumor cells and only reactive gliosis, necrosis, and lymphocytic infiltrates.
CONCLUSION
RNA-LPAs elicit rapid immune activation in the periphery and reprogram the GBM TME into a proinflammatory milieu as evidenced by tissue confirmed pseudoprogression.
Abstract
BACKGROUND
DIPG remains a uniformly fatal disease in dire need of new therapies. There are currently no systemic therapies with proven efficacy against these tumors. To overcome these ...barriers, we developed a systemic mRNA lipid particle (LP) vaccine that localizes to tumors and reticuloendothelial (RE) organs to modulate both innate and adaptive immunity against poorly immunogenic tumors like DIPG.
OBJECTIVE
We sought to assess whether RNA-LPs encoding for model antigens (e.g. H3K27M) would reprogram innate immunity and simultaneously elicit sustained adaptive immunity against diffuse midline glioma (DMG).
RESULTS
RNA-LP encoding for model antigens elicit massive recruitment of nearly all monocytes and lymphocytes to RE organs secondary to a danger response mediated by release of orchestrated cytokines (IL-12, TNF-α, IFN-α) and chemokines (CCL2, CCL4, CXCL9-10). This corresponds to increases in absolute numbers of activated DCs and T cells in the RE organs of mice and reprogramming the glioma tumor microenvironment in canines (pet dogs with spontaneous disease). In neonatal mice inoculated midline with established murine K2 gliomas, we observed that RNA-LP vaccines encoding for H3K27M (beginning at ~day 30) elicit significant long-term survivorship, which appears curative in the bulk of animals treated. While H3K27M specific constructs appeared superior, we observed improved survivorship with irrelevant mRNA species (i.e. pp65 and GFP) suggesting these tumors to be particularly sensitive to innate immune modulation. In mice with DMGs, we observed clinical symptomatology of edema/hydrocephalus followed by improvement in many animals suggesting pseudoprogression from intratumoral inflammation and remodeling.
CONCLUSION
RNA-LPs reprogram the tumor microenvironment of poorly immunogenic tumors in effect making them ‘hot.’ Treatment responses in murine models of advanced DMGs are encouraging. We are advancing a final RNA-LP formulation for FDA-IND submission and early phase clinical trials for DIPG through multi-institutional consortia.
Cancer immunotherapy remains limited by poor antigenicity and a regulatory tumor microenvironment (TME). Here, we create “onion-like” multi-lamellar RNA lipid particle aggregates (LPAs) to ...substantially enhance the payload packaging and immunogenicity of tumor mRNA antigens. Unlike current mRNA vaccine designs that rely on payload packaging into nanoparticle cores for Toll-like receptor engagement in immune cells, systemically administered RNA-LPAs activate RIG-I in stromal cells, eliciting massive cytokine/chemokine response and dendritic cell/lymphocyte trafficking that provokes cancer immunogenicity and mediates rejection of both early- and late-stage murine tumor models. In client-owned canines with terminal gliomas, RNA-LPAs improved survivorship and reprogrammed the TME, which became “hot” within days of a single infusion. In a first-in-human trial, RNA-LPAs elicited rapid cytokine/chemokine release, immune activation/trafficking, tissue-confirmed pseudoprogression, and glioma-specific immune responses in glioblastoma patients. These data support RNA-LPAs as a new technology that simultaneously reprograms the TME while eliciting rapid and enduring cancer immunotherapy.
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•RNA-LPAs mimic dangerous emboli for lymphoreticular entrapment and systemic immunity•Systemic immunity resets both the peripheral and intratumoral milieu via IFNAR1/RIG-I•RNA-LPAs are safe and effective tumor re-modulators in canines with spontaneous gliomas•RNA-LPAs reprogram the TME and elicit adaptive immunity in human GBM patients
Systemically administered mRNA aggregates (RNA-LPA) transfect lymphoreticular organs, inducing a massive cytokine/chemokine response that rapidly reprograms the tumor microenvironment while mobilizing dendritic cells/lymphocytes to elicit rapid and enduring cancer immunotherapy.
Abstract
BACKGROUND
Pathogen recognition receptor (PRR) activation is requisite for igniting the immune response and making the tumor microenvironment ‘hot’ during oncogenesis. We theorized that ...these PRRs would remain present in ICI responsive tumors and could be challenged using pan-PRR mimic to prospectively predict brain cancer immunogenicity and response to immune checkpoint inhibitors (ICIs).
METHODS
By layering mRNA into multilamellar nanoparticles (ML RNA-NPs), multiple pathogen recognition receptors can be simultaneously activated in individualized cancer cells serving as a broad screen to test tumor immunogenicity. We challenged murine brain tumor lines known to respond (GL261 and SMA-560) or resist ICI treatment (KR158b and CT2A) with ML RNA-NPs and analyzed downstream production of proinflammatory cytokines as predictors of ICI response.
RESULTS
We demonstrated that ML-RNA-NPs can activate multiple PRRs simultaneously. Following ML RNA-NP challenge, ICI responsive tumors GL261 and SMA-560 (compared to more ICI resistant lines KR158b and CT2A) elicited increased production in pro-inflammatory cytokines such as IFN-β and IL-6 and in CCL4. To further develop this work into a commercially viable tool to predict ICI response, we developed 3D modeling of glial tumors for ML RNA-NP challenge and immunogenicity prediction. We enrolled canines with primary gliomas and began growing their tumoroids in 3D using liquid-like solid (LLS) technology. Using this pipeline, we successfully perfused 3D tumoroids with ML RNA-NP demonstrating ability to set up real-time patient derived explants to predict immunogenicity. We demonstrated that mRNA perfusion of 3D tumoroids elicited similar cytokine response observed with 2D culture of cell-lines.
CONCLUSION
Our results indicate that cytokine signatures following ML RNA-NP challenge differ significantly from ICI responsive versus non-responsive brain tumors. These findings allow for creation of a diagnostic assay to quickly assess brain tumor immunogenicity, allowing for informed treatment with ICIs.
Abstract
BACKGROUND
Although mRNA vaccines have been deployed with great success against COVID-19, unlocking this technology against glioblastoma will necessitate new lipid-nanoparticle formulations ...that overcome cancer tolerance and immunosuppression.
OBJECTIVE/METHODS
We sought to develop a novel mRNA vaccine system to make tolerogenic tumor antigens appear more dangerous through use of unmodified nucleosides (pathogen associated molecular patterns, PAMPs) and highly cationic lipid shells that elicit a systemic damage response against cancer antigens.
RESULTS
We developed a novel vaccine formulation that increases payload packaging of tumor amplified mRNA into multilamellar (onion-shaped) particles for systemic (intravenous) administration. We demonstrate significant immunogenicity and efficacy of multilamellar RNA-NPs in syngeneic murine models for high-grade glioma (KR158b-pp65), and diffuse midline glioma (H3K27M DMG). Remarkably, RNA-NPs significantly improve median survival outcomes of DMG bearing mice beginning therapy at endpoint (Day 35 after midline intracranial implantation). Unlike prototypical mRNA vaccines that activate endosomal toll-like receptors (i.e. TLR7), multilamellar RNA-NPs elicit immunologic response predominantly through intracellular pathogen recognition receptors (RIG-I); long-term survival benefits from RNA-NPs were completely abrogated in RIG-I knockout mice. In canines (pet dogs) with spontaneous gliomas, RNA-NPs elicit massive recruitment/activation of peripheral blood mononuclear cells (PBMCs) which correlate with their trafficking into lymphoreticular organs (in follow-up murine studies). In canines receiving neoadjuvant RNA-NPs, prior to glioma biopsy, we see significant reprogramming of the glioma microenvironment with increased gene signatures for antigen processing/presentation, interferon signaling and cytotoxicity. Upon translation into human clinical trials for glioblastoma patients (NCT04573140), RNA-NPs elicit rapid (within hours) release of cytokines (e.g. IL-1, IL-6, IL-12 TNF-α, interferons) and chemokines (e.g. MIP1α, MCP-1, IP-10), which correlate with mobilization of PBMCs and activation of dendritic cells/CD8 lymphocytes.
CONCLUSION
First-in-human application of systemic multilamellar RNA-NP vaccines results in significant biologic effects and rapid immunologic reprogramming.
Objective
The standard method of generating disorder‐specific disability scores has lay raters make rankings between pairs of disorders based on brief disorder vignettes. This method introduces bias ...due to differential rater knowledge of disorders and inability to disentangle the disability due to disorders from the disability due to comorbidities.
Methods
We propose an alternative, data‐driven, method of generating disorder‐specific disability scores that assesses disorders in a sample of individuals either from population medical registry data or population survey self‐reports and uses Generalized Random Forests (GRF) to predict global (rather than disorder‐specific) disability assessed by clinician ratings or by survey respondent self‐reports. This method also provides a principled basis for studying patterns and predictors of heterogeneity in disorder‐specific disability. We illustrate this method by analyzing data for 16 disorders assessed in the World Mental Health Surveys (n = 53,645).
Results
Adjustments for comorbidity decreased estimates of disorder‐specific disability substantially. Estimates were generally somewhat higher with GRF than conventional multivariable regression models. Heterogeneity was nonsignificant.
Conclusions
The results show clearly that the proposed approach is practical, and that adjustment is needed for comorbidities to obtain accurate estimates of disorder‐specific disability. Expansion to a wider range of disorders would likely find more evidence for heterogeneity.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
