bluuebunny/crossref_metadata_2025_split huggingface dataset:
IMMU-02. GENOMIC AND TRANSCRIPTOMIC CORRELATES OF IMMUNOTHERAPY RESPONSE WITHIN THE TUMOR MICROENVIRONMENT OF LEPTOMENINGEAL METASTASES
Authors: Alvarez-Breckenridge Christopher , Prakadan Sanjay , Markson Samuel , Kim Albert , Nayyar Naema , Kuter Benjamin , Mora Joana , Shaw Brian , Lee Eudocia Quant , Chukwueke Ugonma , Cahill Daniel , Sullivan Ryan , Carter Scott , Shalek Alex , Brastianos Priscilla 
Published: November 2021

Abstract
Leptomeningeal disease (LMD) is a devastating complication of solid tumor malignancies, with dire prognosis and no effective systemic treatment options. Over the past decade, the incidence of LMD has steadily increased due to therapeutics that have extended the survival of cancer patients, highlighting the need for new interventions. To examine the efficacy of immune checkpoint inhibitors (ICI) in patients with LMD, we completed two phase II clinical trials utilizing either Pembrolizumab alone or the combination of Ipilimumab and Nivolumab. We investigated the cellular and molecular features underpinning observed patient trajectories in these trials by applying single-cell RNA and cell-free DNA profiling to longitudinal cerebrospinal fluid (CSF) draws from enrolled patients. We isolated and sequenced 34,742 cells from both the malignant and immune compartment within CSF. Amongst the 19 patients included in the cohort, there were 13 pre-treatment and 24 post-treatment samples, and 9 patients were sampled across multiple timepoints. We detected dynamic changes in immune cell recruitment into the CSF and activation within 30 days of ICI, including increased effector T cell activation and IFN-gamma response pathways within T cells. Moreover, the overall level of IFN-gamma response and antigen processing within 30 days of ICI in malignant cells correlated with survival past clinical trial primary endpoint. Lastly, we observed evidence of longitudinal outgrowth of distinct immunogenic clones over the course of ICI. Overall, our study describes the liquid LMD tumor microenvironment prior to and following ICI treatment and provides unique insights into the compartmental and temporal variation during the course of ICI. Moreover, our findings demonstrate the clinical utility of cell- free and single-cell genomic measurements for LMD research.
IMMU-08. NOVEL NANOPARTICLE-BASED DELIVERY OF H3.3K27M PEPTIDE TO TUMOR-ASSOCIATED MACROPHAGES ENHANCES THE TUMOR HOMING OF H3.3K27M-TCR TRANSDUCED T-CELLS IN HLA-A2/DR1 TRANSGENIC MICE WITH H3.3K27M+
Authors: Yamamichi Akane , Chuntova Polly , Kakihara Bunta , Chen Tiffany , Diebold David , Harada Naozumi , Akiyoshi Kazunari , Shiku Hiroshi , Okada Hideho 
Published: November 2021

Abstract
We have identified a novel HLA-A*02:01-restricted CD8 T-cell epitope encompassing the H3.3K27M mutation and a corresponding high-affinity T-cell receptor (TCR) that recognizes the epitope. While the development of adoptive cell transfer therapy using TCR-transduced T-cells holds a promise, we still need to overcome multiple challenges, such as suboptimal T-cell trafficking and the immunosuppressive environment of malignant glioma. For example, tumor-associated macrophages (TAMs) mediate immunosuppression but do not function as effective antigen-presenting cells. We have developed a novel cholesteryl pullulan (CHP) nanogel as a highly biocompatible and efficient vaccine delivery system targeting TAMs. In this study, we investigated whether the CHP nanogel loaded with the H3.3K27M peptide would deliver the peptide to TAMs and convert TAMs to better antigen-presenting cells that enhance the anti- H3.3K27M+ glioma activity of the TCR-transduced T-cells. As a clinically relevant mouse model, we used HLA-A2/HLA-DR1-transgenic mice and generated a syngeneic glioma cell line that expresses H3.3K27M from their astrocytes. We also generated a retroviral vector encoding the H3.3K27M-specific TCR for transduction of mouse T cells. HLA-A2/HLA-DR1-transgenic mice bearing day 16 intracerebral H3.3K27M+ glioma received an intravenous administration of the CHP nanogel along with poly-ICLC, a Toll-like receptor 3 agonist. The mice then received an intravenous infusion of TCR-transduced or control, non-transduced T-cells on the following day. The triple combination regimen with the CHP, poly-ICLC and TCR-transduced T-cells significantly suppressed the tumor growth, associated with increased levels of T-cell infiltration into the tumors compared with the dual-therapy with poly-ICLC and TCR-T-cells without the CHP. Furthermore, TAMs isolated from CHP-treated mice showed evidence of CHP-uptake, abilities to stimulate proliferation of TCR-transduced T-cells, and higher levels of HLA.A2 expression. These results suggest that the antigen-loaded CHP nanogel can promote the local antigen-presentation to T-cells and represent a promising approach for improving the efficacy of adoptive T-cell therapy for gliomas.
IMMU-32. IDENTIFICATION OF TUMOR-ANTIGEN SPECIFIC T CELLS AND THE EFFICACY OF IMMUNOTHERAPY VACCINES FOR GLIOBLASTOMA ANTIGENS DETERMINED USING CANCER IMMUNOGENOMICS APPROACH
Authors: Trivedi Vrunda , Yang Changlin , Yegorov Oleg , Dyson Kyle , Mitchell Duane 
Published: November 2021

Abstract

BACKGROUND
Glioblastoma multiforme (GBM) remains a disease with debilitating survival outcomes. Owing to the heterogeneous nature and low mutation burden, identifying multiple antigens inherent to GBM that may serve as targets for immune-based therapies is attractive. Our aim is to develop a personalized immunotherapy approach using cancer immunogenomics for prospectively identifying neoantigens and uniquely expressed tumor proteins and then selectively expanding T cells against these truly tumor-specific antigens and dendritic cell vaccines to boost the T cell responses.

METHODS
RNAseq and WES was performed for murine KR158-luc GBM tumor. Using a cancer immunogenomics approach that we developed, called the O pen R eading Frame A ntigen N etwork (O.R.A.N.), we identified the immunogenic neoantigens and tumor-associated antigens (TAAs) including cancer testis and developmental antigens, that are aberrantly over-expressed in KR158-luc tumor. All predicted genes were subjected to a gene enrichment strategy and an mRNA library was generated containing predominantly only the target genes but had some background non-specific genes (validated by RNAseq). KR158-luc tumor bearing animals were then treated with dendritic cells loaded with the tumor antigen specific mRNA library. Tumor volume and thus progress was determined using in vivo luciferase imaging technique. Additionally, tetramers specific to several of the predicted antigens were manufactured and the frequency of antigen specific T cells was determined using flow cytometry.

RESULTS
The dendritic cell vaccines were effective in delaying the progression of KR158-luc tumors and we identified T cells targeting several of our predicted antigens in the tumor bearing animals. The antigen specific T cells were detected in the tumor infiltrating lymphocytes as well as in the peripheral lymph organs.

CONCLUSION
We developed a dendritic cell-based vaccination approach targeting all neoantigens and TAAs identified as being tumor-specific and validated our developed immunogenomics pipeline by identifying antigen-specific T cells in the tumor bearing animals against novel GBM antigens.
IMMU-36. B CELL-VACCINE ELICITS LONG TERM IMMUNITY AGAINST GLIOBLASTOMA VIA ACTIVATION AND DIFFERENTIATION OF TUMOR-SPECIFIC CD8+ MEMORY T CELLS
Authors: Hou David , Castro Brandyn , Dapash Mark , Rashidi Aida , Zhang Peng , Han Yu , Lopez-Rosas Aurora , Lesniak Maciej , Miska Jason , Chang Catalina 
Published: November 2021

Abstract
While immunotherapy is used clinically to treat many cancers, its translation into brain tumors remains elusive. The importance of B cells in cancer immunity has become increasingly clear, and we previously developed a B cell-based cellular vaccine (BVax) against glioblastoma (GBM) by further activating 4-1BBL+ B cells with CD40 agonism and IFNγ. BVax were characterized as professional antigen-presenting cells (APCs) that promote CD8+ T cell migration and persistence in murine tumor-bearing brains. This study seeks to understand the mechanisms underlying BVax-induced CD8+ T cell fitness in the tumor microenvironment. Initial transcriptomic analysis highlighted that Bvax express high levels of IL15Rα, indicating their potential ability to trans-present IL15. Considering IL15 trans-presentation is fundamental in T-cell memory differentiation, we used BVax to induce T cell activation in the presence of exogenous IL15. BVax were better capable of activating antigen-specific CD8+ T cells and promoting a memory phenotype when compared to other professional APCs such as dendritic cells (DCs). T cell receptor (TCR) CDR3β sequencing showed that BVax expanded a number of TCR clones in-vitro that were found in brains of CT2A tumor-bearing mice in-vivo. These BVax-activated CD8+ T cells displayed a stronger antigen recall response and unique metabolic profile compared to DC-activated CD8+ T cells as shown by metabolomic analysis of tumor-infiltrating CD8+ T cells. When comparing the anti-tumor effects of CD8+ T cells activated by various APCs, BVax with exogenous IL15 promoted CD8+ T cells that displayed the most potent cytotoxicity against GBM cells in-vitro. Collectively, this study suggests that the IL15/IL15Rα axis and interactions with CD8+ T cell are key factors of BVax therapy in promoting a robust survival benefit and long-term immunologic memory against GBM in preclinical models. Additionally, the development of T cell therapies based on B cell licensing can be a promising future approach for glioblastoma therapy.
IMMU-47. THE ANTIGENIC PROFILE OF MURINE AND HUMAN MEDULLOBLASTOMA
Authors: Yang Changlin , Trivedi Vrunda , Dyson Kyle , Yegorov Oleg , Mitchell Duane 
Published: November 2021

Abstract

BACKGROUND
Cancer immunogenomics represents a complementary approach to the application of genomics in developing novel immunotherapies. We performed a multi-faceted computer algorithm, the Open Reading Frame Antigen Network (O.R.A.N.), on medulloblastoma transcription profiles and predicted antigens across a broad array of antigen classes.

METHODS
Patient-specific HLA haplotypes were called via customized Optitype and Phlat algorithms. Preclinical models- sonic hedgehog driven (Ptch1) and Group 3 MYC-driven (NSC) medulloblastoma were derived from C57BL6 murine strain with known MHC haplotypes. Only expressed mutations such as single nucleotide variations, small indels, gene fusions, and personalized TAAs were used for antigenic epitope predictions. Patient-specific or murine tumor associated antigens (TAA) were selected only if expressed &gt;1 transcript per million (TPM) in tumor and the standardized expression across a human tissue database (29 organs or sub-regions, n=9,141) or a mouse normal tissue database (ENCODE, n=99) was below 1 TPM, respectively. TAA sequences were passed through eight MHC class I and four MHC class II affinity algorithms. All epitopes were screened against a customized human or murine proteomic library to guarantee that epitopes were not shared by other expressed isoforms or genes. Immune deconvolution with single cell RNASeq integration was leveraged for teasing out medulloblastoma immunologic landscape.

RESULTS
MB patients harbor MHC-I restricted 1.9 SNV, 0.1 Indel, 0.5 gene fusions and MHC-II restricted 2.5 SNV, 0.1 Indel and 0.5 gene fusion. 79.4% patients have at least 1 neoantigen. 88.2% patients have at least one immunogenic TAA. Importantly, cancer testis antigens and previously unappreciated neurodevelopmental antigens were found expressed across all medulloblastoma subgroups. We predicted 6 neoantigens and 14 TAAs for murine NSC tumor and 19 neoantigens and 13 TAAs for Ptch1 tumor. CONCULSION: Using a custom antigen prediction pipeline, we identified potential human and murine tumor rejection antigens with important implications for development of medulloblastoma cellular therapies.
IMMU-52. EFFECTS OF IMMUNE CHECKPOINT BLOCKADE ON ANTIGEN-SPECIFIC CD8+ T CELLS FOR USE IN ADOPTIVE CELLULAR THERAPY
Authors: Ogando-Rivas Elizabeth , Castillo Paul , Jones Noah , Trivedi Vrunda , Drake Jeffrey , Dechkovskaia Anjelika , Candelario Kate , Yang Changlin , Mitchell Duane 
Published: November 2021

Abstract

BACKGROUND
Adoptive T-cell therapies have been successfully used as treatment for patients diagnosed with advanced cancers. Unfortunately, for some refractory cancers, they have failed. To overcome this, checkpoint inhibitors have shown to rescue immune anti-tumor responses. We hypothesized that in-vitro checkpoint blockade during T-cell stimulation and expansion with RNA-pulsed dendritic cells may enhance the activity of antigen-specific T-cells and improve the efficacy of ACT platforms.

METHODS
Human PBMCs were isolated from CMV seropositive donors to generate DCs and pulsed them with CMVpp65-mRNA to educate T-cells in co-culture for 15-days. We targeted pp65 antigen which is ubiquitously expressed by glioblastoma cells. Three checkpoint blockade conditions were evaluated (anti-PD1, anti-Tim3 and anti-PD1+Tim3). IL2 was added every 3 days as well as the blockade antibodies. Immunephenotyping was performed on Day-0 and Day-15. Polyfunctional antigen specific responses were evaluated upon rechallenge with CMVpp65 peptides.

RESULTS
CMVpp65 activated CD8+ T-cells upregulate Lag3 and Tim3 (p= &lt; 0.0001). Tim3 blockade alone or in combination led to a significant upregulation of Lag3 expression on CD8+pp65Tetramer+ central memory, effector memory, and TEMRA T-cells. This latter T-cell subset uniquely maintain double-positive Tim3/Lag3 expression after blockade. In contrast, PD-1 blockade had minimal effects on Tim3 or Lag3 expression. In addition, IFN-g secretion was reduced in T-cells treated with Tim3 blockade in a dose-dependent manner (p= 0.004).

CONCLUSION
In this study, we have identified a potential activating component of Tim3 and linkage between Tim3 and Lag3 signaling upon blocking Tim3 axis during T-cell antigen presenting cell interactions that should be considered when targeting immune checkpoints for clinical use.
INNV-01. THE CASE OF LEPTOMENINGEAL CARCINOMATOSIS RELATED HYDROCEPHALUS MANAGED WITH SYSTEMIC AND INTRATHECAL CHEMOTHERAPY
Authors: Hrachova Maya , Mrugala Maciej 
Published: November 2021

Abstract

INTRODUCTION
Leptomeningeal carcinomatosis (LC) is an end-stage sequela of metastatic cancer that commonly leads to severe neurological symptoms due to hydrocephalus and commonly treated with surgery or radiation. As these procedures are invasive and have associated risks, chemotherapy could be a great alternative. We report a case of a hydrocephalus related to LC in a patient with Stage IV breast cancer that resolved after the administration of HD-MTX and intrathecal cytarabine.

CASE
A 64-year-old right-handed woman with Stage IV ER positive, PR positive, HER2 negative invasive lobular carcinoma of the left breast on chemotherapy with palbociclib and alpelisib who presented with mild occipital headaches, diplopia and imbalance. Imaging revealed an extensive abnormal leptomeningeal enhancement withing the posterior fossa compatible with leptomeningeal carcinomatosis. CSF cytology was consistent with metastatic adenocarcinoma. Liquid biopsy detected circulating tumor cells. During the admission for the cycle 1 of systemic chemotherapy with HD-MTX and intrathecal cytarabine, neurological status deteriorated as she became stuporous due to the newly developed moderate obstructive and communicating hydrocephalus. Surgical innervation was considered but given her response to serial Ommaya taps and dexamethasone, we proceeded with observation. Symptomatic improvement was noted within few days and confirmed on imaging showing the resolution of previously seen hydrocephalus.

DISCUSSION
This case highlights the role of non-invasive combination of systemic and intrathecal chemotherapy in patients with LC-related hydrocephalus aimed to preserve patient’s quality of life. No relevant disclosures.
INNV-06. BRAF AND MEK DUAL INHIBITORS THERAPY IN RECURRENT OR ANAPLASTIC PLEOMORPHIC XANTHOASTROCYTOMA (PXA)
Authors: Kata Karolina , Quintero Juan Carlos Rodriguez , Arevalo-Espejo Octavio , Bhattacharjee Meenakshi Bidwai , Ware Cornelius , Dono Antonio , Riascos-Castaneda Roy , Tandon Nitin , Blanco Angel , Esquenazi Yoshua , Ballester Leomar Y , Amsbaugh Mark , Day Arthur L , Zhu Jay-Jiguang 
Published: November 2021

Abstract

BACKGROUND AND OBJECTIVE
Recurrent and anaplastic pleomorphic xanthoastrocytoma (PXA) tumors are challenging to treat due to their rarity and lack of management consensus. About 80% of PXAs harbor BRAF gene mutation. Although the development of BRAF inhibitors has dramatically improved the outcomes for patients with BRAF V600E mutant tumors, resistance develops in the majority of cases. We hypothesize that dual BRAF/MEK inhibitors therapy can improve tumor control and patient survival without added toxicity.

METHODS
Medical records from 2010 to 2021 in Memorial Hermann Texas Medical Center were reviewed. Patients diagnosed with PXA who received BRAF and/or MEK inhibitors therapies were identified. The data evaluated included age, sex, treatment received, side effects, and outcomes, as well as results from blood tests, pathology, next generation sequencing and MRI. Side effects were evaluated according to the CTCAE Version 5.0.

RESULTS
Five patients with recurrent or anaplastic PXA were identified. The median age at diagnosis was 22 years old (range 14-66 years old), with 60% male, and 60% grade III. All patients received BRAF/MEK dual inhibitors therapy at various stages of PXA treatment. The median follow-up was 72 months (range 17-108 months). One patient (66 years old) experienced short-term disease stability for 5 months and who died from tumor related brain hemorrhage while off therapy for 9 months. Four patients experienced long-term disease control (17, 22, 94, 108 months, respectively) while three of them remain on dual therapy and one patient died from systemic PXA progression. Dual BRAF/MEK inhibitors were well tolerated with only grade 1-2 adverse effects (AE) including skin rash, fatigue, mild abdominal discomfort, diarrhea. No grade III-V AE were detected.

CONCLUSION
BRAF/MEK dual inhibitor can provide potential clinical benefit to PXA patients with BRAF mutations. Our study supports the concurrent use of BRAF/MEK inhibitors for best tumor control without unexpected AE.
INNV-08. LOW AND INTERMEDIATE GRADE GLIOMA UMBRELLA STUDY OF MOLECULAR GUIDED THERAPIES (LUMOS) STUDY
Authors: Kong Benjamin , Sim Hao-Wen , Amanuel Benhur , Day Bryan , Buckland Michael , Verhaak Roel , Yip Sonia , Johns Terrance , Lwin Zarnie , Rosenthal Mark , Nowak Anna K , Barnes Elizabeth H , Scott Andrew M , Parkinson Jonathon , Jeffree Rosalind , Lourenco Richard De Abreu , Lau Peter , Whittle James , Hovey Elizabeth , Cher Lawrence , Kichendasse Ganessan , Hall Merryn , Robinson Cleo , Thomas Marc , Giardina Tindaro , Tu Emily , Khasraw Mustafa , Koh Eng-Siew , Gan Hui 
Published: November 2021

Abstract

BACKGROUND
Grade 2 and 3 (G2/3) gliomas are the second largest group of brain tumors in adults. Although the prognosis for G2/3 gliomas at the time of relapse mirror those of glioblastoma, there are few trials in this space.

METHODS
LUMOS was a national multi-center pilot study for patients with relapsed G2/3 gliomas designed to match contemporaneous tissue obtained at the time of disease progression with subsequent targeted therapies. The objective was to establish the feasibility of a precision oncology, umbrella approach to obtain and type tissue within a useful timeframe. As a key feature of LUMOS, a multidisciplinary Molecular Tumor Advisory Panel (MTAP) with subspecialty neuro-oncology expertise was formed to interpret the complex genomic information and provide a simplified recommendation to the treating physician.

RESULTS
Ten patients (median age 42: range 32-62; four G2 astrocytoma, one G3 astrocytoma, three G2 oligoendroglioma, one G3 oligodendroglioma, one mixed tumor) were enrolled in the study. Eight patients had biopsies within 6 months of study entry whilst two underwent a biopsy during the study. All patients had potentially targetable alterations (10 IDH, 3 FGFR, 2 PIK3K, CCND3, NRAS, CDK4, PRPRZ1-MET fusion and MET amplification). Matched therapies were delivered for two patients via compassionate access outside the study. The median turnaround time (TAT) of MTAP reports was 6.2 weeks (range 4.2-9.7 weeks) but 4.6 weeks when lag time for shipping was removed.

CONCLUSION
LUMOS confirmed that this design was feasible with good turnaround times. The MTAP facilitated education and support for treating physicians. Thes findings support moving to a larger study using contemporaneous and longitudinal tissue samples matched with targeted therapies as part of a comprehensive umbrella study design. Delivery and interpretation of molecular data is a challenge shared across oncology which may be mitigated with a neuro-oncology specific molecular tumor board.
INNV-19. NAVIGATING GLIOBLASTOMAS THE DIGITAL WAY: AN OBSERVATIONAL OVERVIEW OF THE USE OF A SMARTPHONE WEB APPLICATION IN A GBM PATIENT POPULATION
Authors: Fine Catherine , Brown Jon , Tozour Erin , Mason Chris , Wels Stephanie , Radick Zack , Tucker Simon , Bilstein Alex , Gottlieb Jordan , Lee Tammy , Devitte Ashley , Corbett Kevan , Scherer Stefan , Meyerrose Todd 
Published: November 2021

Abstract
There is limited data regarding the use of digital resources in the neuro-oncology clinic, and more specifically within the glioblastoma (GBM) patient population. Studies show that smartphone applications are feasible as a resource to improve patient-reported outcomes, produce actionable provider data, and actively engage patients in their care, leading to patients being empowered in their choices, apt to adhere to recommendations and producing quality conversations with providers. Navio, an oncology digital health company, helps patients, providers, researchers, and industry collaborators by offering personalized treatment regimens, appointment reminders, help with medication use, diagnosis education, resources, and a means to record quality of life and patient-generated health data, which can be surfaced in real-time to oncology care teams. Seventy-seven patients with a GBM, ages 25-74 years, who were beginning or receiving treatment, were invited via SMS text to access the Navio web application. Nine different GBM treatment plans and 10 different countries were represented among the patients. Patients were allowed unlimited access to all modules and encouraged by text to re-engage, at Navio-defined key moments. Of the invited patients, 58 / 77 (75 %) successfully self-onboarded to Navio’s app. Of the 58 patients onboarded, 77 % continued to engage with the application at various time points past day 1 and as far out as day 180. Engagement was seen across all age groups. Navio was able to re-engage 60 % of all patients who had 7 days of inactivity. Oncology digital resources, such as Navio’s app, are of increasing interest to gather and surface real-time data, and support patients outside of traditional clinic visits. Although early, Navio’s application represents a unique and expanding opportunity to engage and empower GBM patients, specifically during key treatment moments, to provide information for patients and their oncology care teams, and most importantly, to improve patient outcomes.