Brief Report: Comprehensive Clinicogenomic Profiling of Small Cell Transformation From EGFR-Mutant NSCLC Informs Potential Therapeutic Targets

Introduction

NSCLC transformation to SCLC has been best characterized with EGFR-mutant NSCLC, with emerging case reports seen in ALK, RET, and KRAS-altered NSCLC. Previous reports revealed transformed SCLC from EGFR-mutant NSCLC portends very poor prognosis and lack effective treatment. Genomic analyses revealed TP53 and RB1 loss of function increase the risk of SCLC transformation. Little has been reported on the detailed clinicogenomic characteristics and potential therapeutic targets for this patient population.

Methods

In this study, we conducted a single-center retrospective analysis of clinical and genomic characteristics of patients with EGFR-mutant NSCLC transformed to SCLC. Demographic data, treatment course, and clinical molecular testing reports were extracted from electronic medical records. Kaplan-Meier analyses were used to estimate survival outcomes. Next generation sequencing-based assays was used to identify EGFR and co-occurring genetic alterations in tissue or plasma before and after SCLC transformation. Single-cell RNA sequencing (scRNA-seq) was performed on a patient-derived-xenograft model generated from a patient with EGFR-NSCLC transformed SCLC tumor.

Results

A total of 34 patients were identified in our study. Median age at initial diagnosis was 58, and median time to SCLC transformation was 24.2 months. 68% were female and 82% were never smokers. 79% of patients were diagnosed as stage IV disease, and over half had brain metastases at baseline. Median overall survival of the entire cohort was 38.3 months from initial diagnoses and 12.4 months from time of SCLC transformation. Most patients harbored EGFR exon19 deletions as opposed to exon21 L858R alteration. Continuing EGFR tyrosine kinase inhibitor post-transformation did not improve overall survival compared with those patients where tyrosine kinase inhibitor was stopped in our cohort. In the 20 paired pretransformed and post-transformed patient samples, statistically significant enrichment was seen with PIK3CA alterations (p = 0.04) post-transformation. Profiling of longitudinal liquid biopsy samples suggest emergence of SCLC genetic alterations before biopsy-proven SCLC, as shown by increasing variant allele frequency of TP53, RB1, PIK3CA alterations. ScRNA-seq revealed potential therapeutic targets including DLL3, CD276 (B7-H3) and PTK7 were widely expressed in transformed SCLC.

Conclusions

SCLC transformation is a potential treatment resistance mechanism in driver-mutant NSCLC. In our cohort of 34 EGFR-mutant NSCLC, poor prognosis was observed after SCLC transformation. Clinicogenomic analyses of paired and longitudinal samples identified genomic alterations emerging post-transformation and scRNA-seq reveal potential therapeutic targets in this population. Further studies are needed to rigorously validate biomarkers and therapeutic targets for this patient population.

pan-MHC and cross-Species Prediction of T Cell Receptor-Antigen Binding

Profiling the binding of T cell receptors (TCRs) of T cells to antigenic peptides presented by MHC proteins is one of the most important unsolved problems in modern immunology. Experimental methods to probe TCR-antigen interactions are slow, labor-intensive, costly, and yield moderate throughput. To address this problem, we developed pMTnet-omni, an Artificial Intelligence (AI) system based on hybrid protein sequence and structure information, to predict the pairing of TCRs of αβ T cells with peptide-MHC complexes (pMHCs). pMTnet-omni is capable of handling peptides presented by both class I and II pMHCs, and capable of handling both human and mouse TCR-pMHC pairs, through information sharing enabled this hybrid design. pMTnet-omni achieves a high overall Area Under the Curve of Receiver Operator Characteristics (AUROC) of 0.888, which surpasses competing tools by a large margin. We showed that pMTnet-omni can distinguish binding affinity of TCRs with similar sequences. Across a range of datasets from various biological contexts, pMTnet-omni characterized the longitudinal evolution and spatial heterogeneity of TCR-pMHC interactions and their functional impact. We successfully developed a biomarker based on pMTnet-omni for predicting immune-related adverse events of immune checkpoint inhibitor (ICI) treatment in a cohort of 57 ICI-treated patients. pMTnet-omni represents a major advance towards developing a clinically usable AI system for TCR-pMHC pairing prediction that can aid the design and implementation of TCR-based immunotherapeutics.

Immune cellular patterns of distribution affect outcomes of patients with non-small cell lung cancer

Studying the cellular geographic distribution in non-small cell lung cancer is essential to understand the roles of cell populations in this type of tumor. In this study, we characterize the spatial cellular distribution of immune cell populations using 23 makers placed in five multiplex immunofluorescence panels and their associations with clinicopathologic variables and outcomes. Our results demonstrate two cellular distribution patterns-an unmixed pattern mostly related to immunoprotective cells and a mixed pattern mostly related to immunosuppressive cells. Distance analysis shows that T-cells expressing immune checkpoints are closer to malignant cells than other cells. Combining the cellular distribution patterns with cellular distances, we can identify four groups related to inflamed and not-inflamed tumors. Cellular distribution patterns and distance are associated with survival in univariate and multivariable analyses. Spatial distribution is a tool to better understand the tumor microenvironment, predict outcomes, and may can help select therapeutic interventions.

Abstract 125: Archival single cell sequencing reveals persistent subclones over years to decades of DCIS progression

Ductal carcinoma in situ (DCIS) is a common precursor of invasive breast cancer (IBC), yet the genomic progression to recurrent disease remains poorly understood. A main contributor to this gap in knowledge arises from technical challenges with genomic profiling of formalin-fixed paraffin-embedded (FFPE) materials. To address this challenge, we developed Arc-well, the first high-throughput method that can perform single cell DNA sequencing of thousands of cells from FFPE materials and frozen tissues. Using Arc-well, we profiled genomic copy number in 27,851 single cells from 26 archival FFPE tissues that were stored for 3-31 years. Analysis of genomic evolution in 10 patients with matched DCIS and recurrent cancers (DCIS or IBC) separated by 2-16 years showed that many primary DCIS lesions had already undergone whole-genome-doubling and had extensive clonal diversity, similar to the paired recurrence. The data from most patients (8/10) suggest an evolutionary bottleneck model of progression, in which a single subclone persisted during the progression to the recurrent disease, revealing copy number aberrations associated with invasion and recurrence.

Citation Format: Kaile Wang, Tapsi Kumar, Junke wang, Darlan Minussi, Emi Sei, Jianzhuo li, Tuan Tran, Aatish Thennavan, Min Hu, Anna Casasent, Zhenna Xiao, Shanshan Bai, Yuehui Zhao, Amado Zurita, Ana Aparicio, Brian Chapin, Jie ye, Jianjun Zhang, Don Gibbons, Andrew Futreal, Lorraine King, Jeffrey Marks, E. Shelley Hwang, Vandna Shah, Ellinor Sawyer, Petra Kristel, Jelle Wesseling, Esther H. Lips, Nicholas Navin. Archival single cell sequencing reveals persistent subclones over years to decades of DCIS progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 125.

Abstract 3468: Immunoproteasome expression and checkpoint blockade response in advanced non-small cell lung cancer

Responders to checkpoint blockade in Non Small Cell Lung Cancer (NSCLC) often feature an inflamed microenvironment prior to therapy. However, the complete set of molecular drivers connecting this histologic observation to enhanced tumor clearance remain enigmatic.

In updated analysis of the Stand Up 2 Cancer-Mark Foundation (SU2C-MARK) Cohort - a collection of 393 patients with whole exome and/or RNA sequencing along with matched checkpoint blockade response annotation - we identify a prominent predictive role for inducible components of the immunoproteasome, a non-canonical peptide processing complex upstream of antigen presentation. Notably, these subunits are enriched as predictors relative to interferon-inducible genes as well as proteasome components in general, and are consistently associated with objective response, progression-free survival and overall survival. Expression of Immunoproteasome subunits associates positively with TCR (but not BCR) burden, supporting a mechanistic model in which enhanced immunoproteasome processivity leads to superior T-cell recognition. Furthermore, although they are known to be targets of interferon gamma (IFNɣ), we demonstrate that their expression is better modeled via a combination of IFNɣ and tumor necrosis factor-α (TNFα) levels, suggesting they may act as integrators of multiple cytokine cascades.

Given the fact that the immunoproteasome can alter both antigen quantity as well as quality (including peptide cleavage site preference), the enhanced expression of this complex in the setting of checkpoint blockade response may have important implications for modeling of antigen presentation. These data also suggest novel strategies to enhance immune checkpoint blockade.

Citation Format: Vivek Naranbhai, Arvind Ravi, Matthew Hellmann, Monica Arniella, Mark Holton, Samuel Freeman, Chip Stewart, Ignaty Leshchiner, Jaegil Kim, Yo Akiyama, Aaron Griffin, Natalie Vokes, Mustafa Sakhi, Vashine Kamesan, Hira Rizvi, Biagio Ricciuti, Patrick Forde, Valsamo Anagnostou, Jonathan Riess, Don Gibbons, Nathan Pennell, Vamsidhar Velcheti, Subba Digumarthy, Mari Mino-Kenudson, Andrea Califano, John Heymach, Roy Herbst, Julie Brahmer, Kurt Schalper, Victor Velculescu, Brian Henick, Naiyer Rizvi, Pasi Janne, Mark Awad, Andrew Chow, Benjamin Greenbaum, Marta Luksza, Alice Shaw, Jedd Wolchok, Nir Hacohen, Gad Getz, Justin Gainor. Immunoproteasome expression and checkpoint blockade response in advanced non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3468.

Abstract 4460: Spatial profiling of immune biomarkers in resected treatment-naïve early stage lung adenocarcinoma

Background: Recently, neoadjuvant immunotherapy plus chemotherapy has been approved for treatment of resectable non-small cell lung carcinoma (NSCLC). Defining the immune landscape of these tumors and its spatial distribution will help to understand lung cancer biology. Here, we analyzed the distribution of immune-related biomarkers in tumor-defined regions and its associations with clinicopathological variables in resected lung adenocarcinomas using high-plex profiling approaches.

Methodology: Thirty-three FFPE tumor tissues from surgically resected treatment-naïve lung adenocarcinoma stage I/II were used to construct a tissue microarray from the MD Anderson ICON cohort. We used three 1-mm core per patient [2 from central tumor (CT), and 1 from invasive margin (IM)] and performed the GeoMx Digital Spatial Profiling protein protocol to assess 49 immune biomarkers. Pancytokeratin (panCK; epithelial), CD45 (immune) and SYTO 13 (nuclear) were utilized as morphology biomarkers. Regions of interests were placed in cores containing tumor, and segmented in ‘”Tumor (Tu)” (PanCK+) and the “tumor microenvironment (TME)” (PanCK-). Digital counts were normalized using background correction. Statistical analysis was performed using linear mixed model. A p value equal or less than 0.05 was considered significant.

Results: We first compared the relative counts of immune biomarkers in the TME in CT and IM. IM had higher CD3, CD8, CD45RO, as well as CD163 and STING (P ranges 0.006 to 0.035), while CT had higher PD1 (P 0.025). Then we analyzed differential biomarker expression by sex and smoking status. Females had higher counts of Immune related biomarkers: CD45, CD3, CD20, immune checkpoints: PD-L1, VISTA, CTLA4, LAG3, and ICOS, and myeloid: CD68, CD11c, CD163, and B2M (P ranges 0.0005 to 0.046). Smokers had higher counts of CD66b (P 0.007) and B2M (P 0.039) while never smokers had higher counts of HLA-DR, CD34, FoxP3, OX40L, Tim-3, and B7-H3 (P ranges 0.001 to 0.049). Finally, we analyzed Tu segments. IM had higher CD66b, VISTA, CD163, OX40L, HLA-DR, GZMB, STING, and CD8 (P ranges 0.007 to 0.045) than CT. Female patients had higher CD45, CD68, CD11c and CD163 (P ranges 0.008 to 0.045), and males had higher SMA (P 0.005). Smokers had higher CD66b (P 0.007), B2-microglobulin (P 0.043), and never smokers had higher HLA-DR, STING, CD34, CD44, FoxP3 and CD25 (P ranges 0.006 to 0.043).

Conclusions: In this study, biomarker analysis of treatment-naïve adenocarcinoma in CT areas and IM indicates a higher immune response in the IM and presence of inhibitory signaling inside the tumor. Our data also showed that tumors from females have higher immune response than tumors from males, which is concordant with previous studies. Distinct profiling by smoking status was also observed. Further analysis of gene expression analysis of this set is ongoing.

Citation Format: Sharia D. Hernandez, Wei Lu, Alejandra G. Serrano, Claudio J. Arrechedera, Beatriz Sanchez-Espiridion, Nejla Ozirmak, Max Molina, Larisa Kostousov, Sean Barnes, Khaja Khan, Ximing Tang, Junya Fujimoto, Edwin R. Parra, Gabriela Raso, Stephanie T. Schmidt, Carmen Behrens, John Heymach, Jianjun Zhang, Ken Chen, Boris Sepesi, Tina Cascone, Don Gibbons, Ignacio I. Wistuba, Cara Haymaker, Luisa M. Solis. Spatial profiling of immune biomarkers in resected treatment-naïve early stage lung adenocarcinoma. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4460.

Abstract 6513: Single cell and spatial profiling reveal molecular and immune evolution from precancers to invasive lung adenocarcinomas in genetic and carcinogen-induced mouse models

Introduction: An improved understanding of early lung carcinogenesis may facilitate development of novel diagnostic, screening, and prevention strategies to decrease lung cancer mortality. We have previously led a series of studies on the molecular and immune landscape of lung adenocarcinoma (LUAD) precursors. However, resected human specimens only provide molecular snapshots. Here, we sought to establish and characterize human-relevant murine lung precancer models to depict molecular evolution during early lung carcinogenesis and to provide novel insights for lung cancer interception.

Methods: We have established 3 genetically engineered mouse models (GEMMs) (K: KrasLSL-G12D/+, KP: KrasLSL-G12D/+/Trp53R172H/+, KL: KrasLSL-G12D/+/Lkb1fl/fl) and 2 carcinogen-induced models (CITMs) (UWT: Urethane in wild type mice, URG: Urethane in Rag2−/− mice). Lung tissues were serially collected at multiple time points after induction and subjected to whole exome sequencing (WES), single cell RNA sequencing (scRNA-seq), spatial transcriptomics (Visium), and imaging mass cytometry (IMC).

Results: Pathological review of specimens from 252 mice revealed normal lung, precancers and LUAD at different timepoints mirroring the evolution of human LUAD. Overall, the tumor burden was significantly higher in GEMMs than CITMs (p<0.05). Tumor mutation burden progressively increased with progression from precancers to LUADs across all models. scRNA-seq demonstrated a progressive decrease of CD4+ T cell, CD8+ T cell, NK cell, and B cell infiltration in all models except the B/T cell-deficient WRG model; and a progressive increase of neutrophils (in KL model) and macrophages (in K, KP, UWT and URG models) along with progression of precancers. These findings were confirmed by spatial Visium and IMC profiling. Infiltration of T cells, B cells and NK cells inside tumors was not different between GEMMs (K, KP, KL) and CITMs (UWT). However, UWT showed significantly higher density of immune cells at the peritumor regions (P<0.05). Compared to the immune-competent UWT model, the B/T-cell deficient URG model showed similar progression and tumor burden at early phases, but rapid progression and larger tumor burden in the later phases. URG had no mature B/T cells but significantly higher NK cell infiltration than UWT (p<0.05).

Conclusion: We have established 5 murine carcinogen-dependent and -independent precancer models, morphologically resembling human LUAD and its precursors. Although progressive immunosuppression along with progression of lung precancers is universal across all models, the evolution patterns and the molecular/immune features underlying immunosuppression vary in different models, particularly between CITMs and GEMMs. These models may be valuable assets for studying early lung carcinogenesis and lung cancer interception.

Citation Format: Bo Zhu, Jian-Rong Li, Hong Chen, Pingjun Chen, Junya Fujimoto, Yanhua Tian, Muhammad Aminu, Chenyang Li, Lingzhi Hong, Alexandre Reuben, Edwin Roger Parra Cuentas, Ou Shi, Monique Nilsson, Alissa Poteete, Shawna Hubert, Khaja Khan, Wei Lu, Daniel Kraushaar, Xingzhi Song, Jianhua Zhang, Don Gibbons, Luisa Solis Soto, Ignacio Wistuba, Jia Wu, John Heymach, Chao Cheng, Jianjun Zhang. Single cell and spatial profiling reveal molecular and immune evolution from precancers to invasive lung adenocarcinomas in genetic and carcinogen-induced mouse models. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6513.

Abstract 4264: The genomic landscape of RET fusions in non-small cell lung cancer and the impact of co-occurring genomic alterations on the efficacy of selective RET inhibitors

Purpose: RET fusions drive oncogenesis in 1-2% of non-small cell lung cancer (NSCLC) and are sensitive to the selective RET inhibitors selpercatinib and pralsetinib. They have also emerged as mechanisms of acquired resistance to other targeted therapies. The genomic landscape of RET fusions and the impact of co-occurring genomic alterations on the efficacy of selective RET inhibitors is yet to be fully described.

Methods: A total of 678 RET fusion-positive samples were analyzed from three cohorts: Guardant360® circulating tumor DNA (ctDNA) (n=467), tissue and/or plasma from the American Association for Cancer Research Project Genomics Evidence Neoplasia Information Exchange (AACR Project GENIE) non-squamous NSCLC cohort (n=161), and the MD Anderson Cancer Center (MDACC) cohort of patients treated with selpercatinib or pralsetinib (n=50). Molecular characteristics were compared across all three cohorts and to the entire non-RET non-squamous NSCLC AACR Project GENIE cohort (n=17770). Fisher’s exact test was used to evaluate the difference in response rate between patient groups, and Cox proportional hazard models were used to calculate hazard ratios for time-to-event endpoints for patients in the MDACC clinical cohort (n=51, 50 patients with RET fusion, 1 patient with RET point mutation).

Results: The most common fusion partner in all cohorts was KIF5B (ctDNA: 73%; GENIE: 69%; MDACC: 71%), followed by CCDC6 (19%; 17%; 18%) and NCOA4 (5%; 1%; 7%). Across all cohorts, co-mutations in TP53 were most common (60%; 34%; 40%) and EGFR, CDKN2A/B, MET, and ATM consistently co-occurred across all cohorts. EGFR co-occurred more frequently with non-KIF5B fusion partners (chi-square p < 0.006). MYC and CCND1 amplifications were enriched in all three cohorts compared to the non-RET cohort. In the MDACC clinical cohort (n=51), the majority were female, never-smokers, with adenocarcinoma histology. The median follow-up time was 28.3 months (95% CI: 15.2 ~ 35 months). Overall response rate (ORR) was 74.4% (95% CI: 58.8 ~ 86.5%), where patients with TP53 mutation had numerically lower ORR compared to patients without TP53 mutation (58.5% vs. 87.5%; p = 0.0632). Median progression-free survival (PFS) time was 16.5 months (95% CI: 13.5 ~ 27.4 months) and KIF5B fusions trended towards worse PFS outcome compared to non-KIF5B fusions (HR: 2.24; 95% CI: 0.88 ~ 5.67; p = 0.0896). TP53 alterations were associated with a significantly worse overall survival (OS) (HR: 2.93; 95% CI: 1.08 ~ 7.95; p = 0.0346).

Conclusion: In the largest RET fusion-positive NSCLC cohort to date, RET fusions frequently co-occurred with other genomic alterations, most commonly in TP53. TP53 alterations are associated with a significant reduction in overall survival in patients treated with the selective RET inhibitors. Additional analysis is underway.

Citation Format: Tuqa Al Khalaf, Simon Heeke, Lei Feng, Leylah M. Drusbosky, Jeff Lewis, Waree Rinsurongkawong, Vadeerat Rinsurongkawong, Jack Lee, Jianjun Zhang, Don Gibbons, Ara Vaporciyan, Vincent Lam, Vivek Subbiah, John Heymach, Yasir Elamin. The genomic landscape of RET fusions in non-small cell lung cancer and the impact of co-occurring genomic alterations on the efficacy of selective RET inhibitors. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4264.

Abstract 676: ZEB1 acetylation regulates dimerization and protein stability to promote lung adenocarcinoma progression and metastasis

Lung cancer is the leading cause of cancer-related death worldwide due to the ability of cancer cells to metastasize. Therefore, it is essential to expand our current knowledge of the biological processes that contribute to metastasis to guide the discovery of novel therapeutic modalities. The Epithelial-to-mesenchymal transition (EMT) is a mechanism for metastasis, which changes polarized epithelial cells into invasive mesenchymal cells. High expression of the Zinc finger E-box binding homeobox 1 (ZEB1) transcription factor is correlated to poor outcomes in cancer, including therapeutic resistance and EMT-mediated metastasis. ZEB1 has a predicted molecular weight of 125kDa; however, multiple groups have reported discrepancies in the observed molecular weight (approximately 190-250kDa). This has been attributed to dimerization mediated by post-translational modifications (PTMs). Therefore, we performed mass spectrometry and identified a novel PTM - K811 acetylation - that may regulate ZEB1 dimerization and function. To define the role of ZEB1 acetylation, we generated ZEB1 acetyl mimetic (K811Q) and deficient (K811R) mutants in a panel of lung adenocarcinoma cell lines. We hypothesize that ZEB1 acetylation regulates dimerization and protein stability to promote lung adenocarcinoma progression and metastasis. We determined that the acetyl-deficient mutant (125kDa) exhibits a decreased half-life compared to WT and acetylated ZEB1, suggesting that disruption of acetylation hinders dimerization and protein stability. However, the acetyl-mimetic mutant (250kDa) protects ZEB1 from proteasomal degradation brought by the action of the E3 ubiquitin ligase SIAH1. siRNA-mediated silencing of SIAH1 increased the mRNA and protein levels of ZEB1 WT and both acetylation mutants. Importantly, silencing of SIAH1 markedly increased the half-life of 250kDa ZEB1 WT from 18.0hrs to 25.4hrs and acetyl-mimetic from 12.3hrs to 24.0hrs, as well as 125kDa ZEB1 acetyl-deficient from 9.7hrs to 18.3hrs. Although we determined that 250kDa ZEB1 is significantly more stable than 125kDa ZEB1, the increase in the stability by silencing SIAH1 contributes to ZEB1 acetyl-deficient binding at the promoter of its target genes mir200c-141 and SEMA3F. 250kDa ZEB1 WT and acetyl-mimetic recruits the histone deacetylases (HDACs) containing the nucleosome remodeling and deacetylase (NuRD) complex, to promote lung adenocarcinoma invasion and metastasis compared to ZEB1 acetyl-deficient. We further established that the stability of ZEB1 is integral to promoting these mesenchymal features. Our results suggest that ZEB1_K811ac regulates its dimerization and stability to promote lung adenocarcinoma via EMT. Future studies are focused on understanding the role of ZEB1 protein stability to recruit NuRD co-repressor and subsequently mediate tumorigenesis and metastasis.

Citation Format: Mabel G. Perez-Oquendo, Roxsan Manshouri, Don Gibbons. ZEB1 acetylation regulates dimerization and protein stability to promote lung adenocarcinoma progression and metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 676.

Abstract 3580: Integrative genomics of checkpoint blockade response in advanced non-small cell lung cancer

The introduction of checkpoint blockade therapy, specifically anti-PD-1/PD-L1 agents, has transformed the treatment landscape of advanced Non-Small Cell Lung Cancer (NSCLC). While our understanding of the biology underlying immunotherapy in NSCLC is still incomplete, studies to date have established central roles for Tumor Mutation Burden (TMB) and PD-L1 Tumor Proportion Score (PDL1-TPS). In order to expand our understanding of the molecular features underlying response in NSCLC, we describe here the first joint analysis of the Stand Up 2 Cancer-Mark Foundation (SU2C-MARK) Cohort, a collection of 393 patients with whole exome and/or RNA sequencing along with matched checkpoint blockade response annotation. We identify a number of significant associations between molecular features and response, including: 1) favorable and unfavorable genomic subgroups; 2) distinct immune infiltration signatures associated with wound healing (unfavorable) and immune activated (favorable) microenvironments; and 3) a novel de-differentiated tumor-intrinsic subtype characterized by high TMB, immune activation, and enhanced response rate. Taken together, results from this cohort extend our understanding of NSCLC-specific predictors, providing a rich set of molecular and immunologic hypotheses with which to further our understanding of the biology of checkpoint blockade in NSCLC.

Citation Format: Arvind Ravi, Justin Gainor, Monica Arniella, Chip Stewart, Sam Freeman, Mark M. Awad, Patrick Forde, Valsamo Anagnostou, Brian Henick, Jonathan W. Riess, Don Gibbons, Nathan Pennell, Vamisdhar Velcheti, Ignaty Leshchiner, Jaegil Kim, Subba Digumarthy, Mari Mino-Kenudson, John Heymach, Natalie Vokes, Andrew Griffin, Biagio Ricciuti, Naiyer Rizvi, Roy Herbst, Victor Velculescu, Julie Brahmer, Kurt Schalper, Pasi Janne, Jedd Wolchok, Alice Shaw, Nir Hacohen, Gad Getz, Matthew D. Hellmann. Integrative genomics of checkpoint blockade response in advanced non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3580.

Abstract LB219: Preclinical development of NGM438, a novel anti-LAIR1 antagonist monoclonal antibody for the treatment of collagen-rich solid tumors

Background: Collagen is an abundant component of the extracellular matrix-enriched stromal microenvironment of solid cancers. Emerging research suggests that effective anti-tumor immunity and responsiveness to immune checkpoint inhibitor (CPI) therapy, may be subverted by the presence of collagen and tumor stroma. LAIR1 functions as an inhibitory receptor for collagen, and is highly expressed on tumor-associated macrophages, and to an extent on T cells. LAIR1 expression correlates with poor overall survival and CPI therapy resistance. To test the hypothesis that LAIR1 mediates tumor stroma-driven immune suppression and promotes CPI resistance, we generated NGM438, a monoclonal mAb to antagonize LAIR1 activity in solid cancers. Herein, we describe NGM438, characterize LAIR1 expression and distribution in human tumors, and provide evidence that LAIR1 antagonism reverses collagen-driven immune suppression and improves CPI responsiveness in immune cell-based assays and preclinical animal models.

Methods: NGM438 was identified and developed based on its ability to bind specifically to LAIR1, antagonize ligand binding, and reverse collagen-based immune suppression. NGM438 was tested using several immune cell-based functional assays, alone and in combination with the anti-PD1 mAb, pembrolizumab. Expression and distribution of LAIR1 was evaluated using flow cytometry and immunohistochemistry on healthy donor and cancer patient samples. A surrogate anti-mouse LAIR1 antagonist mAb was also developed and evaluated in preclinical animal models in combination with anti-PD1 mAbs.

Results: NGM438 reversed collagen-induced immune suppression in myeloid cells and promoted anti-PD1 mAb-driven T cell responses in immune cell-based functional assays. LAIR1 was expressed on circulating immune cells from cancer patients actively receiving CPI therapy, and was elevated on patient-matched intratumoral macrophages. Histological assessments revealed LAIR1 expression on mononuclear immune cells that infiltrated the parenchyma and collagen-rich tumor stroma across indications. Finally, LAIR1 antagonism, in combination with anti-PD1 mAb treatment, led to significant tumor growth inhibition in a preclinical model resistant to either treatment alone.

Conclusions: NGM438 is a novel LAIR1 antagonist mAb that reverses collagen-based immune suppression. LAIR1 was expressed on cancer patient circulating and intratumoral immune cells, and LAIR1-expressing cells were often found in collagen-rich tumor stroma. Preclinical data demonstrated that LAIR1 antagonism sensitized a resistant mouse tumor model to respond to anti-PD1 mAb treatment. These data support clinical evaluation of LAIR1 antagonist mAb NGM438. We aim to test the hypothesis that LAIR1 mediates collagen-driven immune suppression, alone and in combination with PD1 inhibition, in patients with solid cancers. As such, we will be advancing NGM438 to the clinic in early 2022.

Citation Format: Sisi He, Jiawei Huang, Leticia Rodriguez, Czrina Cortez, Betty Li, Carmence Ho, Amir Ashique, Kalyani Mondal, Vicky Lin, Julie Roda, Hui Tian, Yan Wang, Bin Fan, Igor Mikaelian, James Sissons, Lee Rivera, Don Gibbons, Jonathan Sitrin. Preclinical development of NGM438, a novel anti-LAIR1 antagonist monoclonal antibody for the treatment of collagen-rich solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr LB219.

Abstract 673: The EMT activator ZEB1 initiates polarized secretion of pro-tumorigenic effector proteins to drive lung adenocarcinoma progression

There are few effective therapeutic options for metastatic lung adenocarcinomas (LUADs) that lack actionable mutations in receptor tyrosine kinases, and there is an urgent need to develop a better understanding of the biological basis of LUAD growth and metastasis. Our group has developed mouse models of LUAD metastasis and found that LUAD metastasis is epithelial-to-mesenchymal transition (EMT)-dependent. EMT causes cancer cells to switch their axis of polarity from apical-basal to front-rear, which orients organelles and actinbased cytoskeletal structures in ways that facilitate purposeful cancer cell motility and metastasis. The EMT-activating transcription factor ZEB1 silences microRNAs that target key inhibitors of the polarity axis switch. These data support the general belief that EMT-dependent metastasis is a cell-autonomous process. However, our new findings here show that ZEB1 coordinates the components of secretory trafficking machinery, Rab6A and Rab8A, via silencing miR-148a that target these effectors, to drive polarized secretory trafficking toward the leading edge of LUAD cells, to enhance surface exposure of MMP14 so that triggers ECM degradation, accelerates focal adhesion turnover and promotes cancer cell migration. Moreover, the ZEB1-driven secretory trafficking increases the secretions of cytokines and immunomodulation factors, to generate an immunosuppressive tumor microenvironment, and to promote LUAD metastasis. These findings advance a paradigm in which EMT drives LUAD metastasis through a cell non-autonomous mechanism. The novelty rests in our results that demonstrate a transcriptional governance of polarized vesicular transport, providing the potential to target ZEB1-driven secretory pathways for the purpose of blocking metastasis in LUAD.

Citation Format: Guan-Yu Xiao, Xiaochao Tan, Leticia Rodriguez, Xin Liu, Jiang Yu, Mayra Vasquez, Hai Tran, William Russell, Don Gibbons, Jonathan Kurie. The EMT activator ZEB1 initiates polarized secretion of pro-tumorigenic effector proteins to drive lung adenocarcinoma progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 673.

The histologic phenotype of lung cancers is associated with transcriptomic features rather than genomic characteristics

Histology plays an essential role in therapeutic decision-making for lung cancer patients. However, the molecular determinants of lung cancer histology are largely unknown. We conduct whole-exome sequencing and microarray profiling on 19 micro-dissected tumor regions of different histologic subtypes from 9 patients with lung cancers of mixed histology. A median of 68.9% of point mutations and 83% of copy number aberrations are shared between different histologic components within the same tumors. Furthermore, different histologic components within the tumors demonstrate similar subclonal architecture. On the other hand, transcriptomic profiling reveals shared pathways between the same histologic subtypes from different patients, which is supported by the analyses of the transcriptomic data from 141 cell lines and 343 lung cancers of different histologic subtypes. These data derived from mixed histologic subtypes in the setting of identical genetic background and exposure history support that the histologic fate of lung cancer cells is associated with transcriptomic features rather than the genomic profiles in most tumors.

The molecular determinants of lung cancer histologic subtypes are not well understood. Here the authors analyze lung cancers of mixed histology and find that histologic subtypes are associated with transcriptomic features rather than genomic profiles in most tumors.

174 Combined IL-2, agonistic CD3 and 4–1BB stimulation preserve clonotype hierarchy in propagated non-small cell lung cancer tumor-infiltrating lymphocytes

Background

While immune checkpoint blockade is regarded as standard of care for treatment of non-small cell lung cancer (NSCLC), up to 50% of patients with metastatic NSCLC do not achieve an optimal response.1–3 Previous work by our group and others in adoptive cell therapy (ACT) of metastatic melanoma (MM) has shown that infusion of a CD8+-rich TIL product significantly improved clinical outcomes, yet traditional IL-2 expansion methods have resulted in a predominantly CD4+ NSCLC TIL expansion product.7–12 This preclinical study explores the feasibility of producing a tumor-specific, CD8+-enriched NSCLC TIL product for ACT with an improved culture method.

Methods

TIL from resected NSCLC tumors were cultured using 1) the traditional method using IL-2 alone in 24-well plates (TIL 1.0) or 2) IL-2 in combination with agonistic antibodies against CD3 and 4-1BB (Urelumab) in a G-Rex flask (TIL 3.0). Expanded TIL were phenotyped using flow cytometry for CD4 and CD8 subset assessment and the CDR3-beta variable region of the T-cell receptor (TCR) involved in antigen binding was sequenced to assess the T-cell repertoire.

Results

In a shorter manufacturing time (median of 14 days vs 27.5 days), TIL 3.0 expanded on average 5.3-times more NSCLC TIL (95% CI= 4.3–6.2, p<0.0001) and achieved a higher expansion success rate than the traditional TIL 1.0 method (100% vs 62.5%, respectively, p<0.0001). Additionally, TIL 3.0 greatly enriched for CD3+CD8+ TIL (81.8% vs 36.9%, p=0.001) and expanded a larger breadth of clonotypes (p=0.039) which shared greater homology with the total clonotypes found in the repertoire of the resected tumor (p=0.0007), and contained a greater fraction of the clones found at high frequency in the tumor (p<0.00001). TIL 3.0 also retained a higher proportion of putative tumor-specific TCR when compared to TIL 1.0 (p=0.0039), defined based on exclusion of known viral-specific TCR and other TCR found in the paired uninvolved lung tissue.

Conclusions

This study reports the feasibility of using the TIL 3.0 methodology to robustly expand a CD8+ T-cell repertoire which maintains the respective clonal hierarchy in NSCLC tumors and enriches for putative tumor-specific TIL clones. The robustness and speed of the new process may facilitate testing and implementing effective TIL ACT in NSCLC.

References

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Borghaei H, Paz-Ares L, Horn L, Spigel DR, Steins M, Ready NE, et al. Nivolumab versus Docetaxel in Advanced Nonsquamous Non-Small-Cell Lung Cancer. N Engl J Med 2015;373(17):1627–39.

Gettinger S, Horn L, Jackman D, Spigel D, Antonia S, Hellmann M, et al. Five-Year Follow-Up of Nivolumab in Previously Treated Advanced Non-Small-Cell Lung Cancer: Results from the CA209–003 Study. J Clin Oncol 2018;36(17):1675–84.

Melioli G, Ratto G, Guastella M, Meta M, Biassoni R, Semino C, et al. Isolation and in vitro expansion of lymphocytes infiltrating non-small cell lung carcinoma: functional and molecular characterisation for their use in adoptive immunotherapy. Eur J Cancer 1994;30A(1):97–102.

McGranahan N, Furness AJ, Rosenthal R, Ramskov S, Lyngaa R, Saini SK, et al. Clonal neoantigens elicit T cell immunoreactivity and sensitivity to immune checkpoint blockade. Science 2016;351(6280):1463–9.

Rosenberg SA, Yang JC, Sherry RM, Kammula US, Hughes MS, Phan GQ, et al. Durable complete responses in heavily pretreated patients with metastatic melanoma using T-cell transfer immunotherapy. Clin Cancer Res 2011;17(13):4550–7.

Besser MJ, Shapira-Frommer R, Treves AJ, Zippel D, Itzhaki O, Hershkovitz L, et al. Clinical responses in a phase II study using adoptive transfer of short-term cultured tumor infiltration lymphocytes in metastatic melanoma patients. Clin Cancer Res 2010;16(9):2646–55.

Pilon-Thomas S, Kuhn L, Ellwanger S, Janssen W, Royster E, Marzban S, et al. Efficacy of adoptive cell transfer of tumor-infiltrating lymphocytes after lymphopenia induction for metastatic melanoma. J Immunother 2012;35(8):615–20.

Radvanyi LG, Bernatchez C, Zhang M, Fox PS, Miller P, Chacon J, et al. Specific Lymphocyte Subsets Predict Response to Adoptive Cell Therapy Using Expanded Autologous Tumor-Infiltrating Lymphocytes in Metastatic Melanoma Patients. Clinical Cancer Research 2012;18(24):6758–70.

Forget MA, Haymaker C, Hess KR, Meng YJ, Creasy C, Karpinets T, et al. Prospective Analysis of Adoptive TIL Therapy in Patients with Metastatic Melanoma: Response, Impact of Anti-CTLA4, and Biomarkers to Predict Clinical Outcome. Clin Cancer Res 2018;24(18):4416–28.

Ben-Avi R, Farhi R, Ben-Nun A, Gorodner M, Greenberg E, Markel G, et al. Establishment of adoptive cell therapy with tumor infiltrating lymphocytes for non-small cell lung cancer patients. Cancer Immunol Immunother 2018;67(8):1221–30.

Ma Y, Ou J, Lin T, Chen L, Wang J, Qiao D, et al. Phenotypic analysis of tumor-infiltrating lymphocytes from non-small cell lung cancer and their potential application for adoptive cell therapy. Immunopharmacol Immunotoxicol 2020;42(4):319–29

Ethics Approval

This study was performed on NSCLC tumor tissue resected from 16 patients enrolled, following informed consent, in the ImmunogenomiC prOfiling of early-stage NSCLC (ICON) project. This study was approved by the University of Texas MD Anderson Cancer Center‘s Institutional Review Board (protocol number PA15-1112_MODCR001).

46 Proximity between cytotoxic antigen-experienced T cells and tumor cells is associated with improved clinical outcomes in early-stage NSCLC

Background

While the development of immunotherapies has improved the treatment of non-small cell lung cancer (NSCLC), most patients still fail to respond. Immune cell densities have been utilized to predict clinical responses but have largely failed to do so. However, the spatial distribution and interaction of these cells at the tissue level have been less studied. Here, we performed spatial analysis of the cells within the tumor immune microenvironment in order to evaluate their relationship with clinical outcomes in early-stage NSCLC.

Methods

Multiplex immunofluorescence was performed on 123 early-stage NSCLC patients from the ICON (Immunogenomic profiling of non-small cell lung cancer) cohort including Cytokeratin (CK), CD3, CD8, CD45RO, FoxP3, CD68, CD20, CD57, Granzyme B (GzmB), PD-1, and PD-L1. Area under the curve (AUC) was calculated using Ripley’s L function, which evaluates the degree of spatial proximity of two cell populations, with a high AUC indicating clustering and low AUC indicating scattering. Findings were integrated with clinical parameters.

Results

Adenocarcinomas demonstrated CD3+PD1+ T cells were closer to CK+ tumor cells (n=60, p=0.035), and B cells were closer to cytotoxic T cells (n=43, p=0.03) than in squamous cell carcinoma. Higher AUC was observed between CD3+PD1+ T cells (n=56, p=0.035), with cytotoxic antigen-experienced T cells (CD45RO+GzmB+) closer to tumor cells (n=35, p=0.017) in stage I and II compared to stage III tumors. Untreated patient tumors exhibited higher proximity between CD20+ B cells and CD57+ NK cells (n=59, p=0.012), CD3+ T cells and PD-L1+ tumor cells (n=56, p=0.027), and CD68+ macrophages and PD-L1+ tumor cells (n=52, p=0.016) than neoadjuvant chemotherapy-treated patients. Patients with no recurrence presented higher AUC in antigen-experienced CD45RO+GzmB+ T cells and tumor cells (n=36, p=0.006), while those with improved survival demonstrated greater proximity between CD68+ macrophages and PD-L1+ tumors (n=52, p=0.016), CD20+ B cells and GzmB+ cells (n=49, p=0.03), and antigen-experienced CD45RO+GzmB+ T cells and tumor cells (n=36, p=0.047). Lastly, patients with improved survival also displayed greater proximity between CD3+CD8+ cytotoxic T cells and PD-L1- epithelial cells (n=76, p=0.04) in tumors versus matched adjacent lungs.

Conclusions

Overall, our findings shed light on some of the potential cell interactions at play in the tumor microenvironment of early-stage NSCLC patients and suggest cell distributions could be utilized to predict clinical outcomes in early-stage NSCLC patients.

962 Integrative immunomics highlight the immunomodulatory impact of neoadjuvant chemotherapy and immune-based treatments in resected non-small-cell lung cancer

Background

How neoadjuvant chemo-immunotherapy modulates tumor immune composition and response is not completely understood. We interrogate immunomodulation of neoadjuvant platinum-based chemotherapy (C), nivolumab (N), and N-plus-C (NC) and their connections to therapeutic efficacy in resected non-small cell lung cancer (NSCLC) by integrating immunomic data from the ImmunogenomiC PrOfiling of NSCLC (ICON) study and NEOSTAR trial cohorts.

Methods

In NEOSTAR (NCT03158129), patients with stage I-IIIA (single N2) resectable NSCLC (AJCC7th) received N (3 mg/kg IV, D1,15,29); patients with stage IB(≥4cm)-IIIA (single N2) resectable NSCLC received NC (N 360 mg IV plus C, D1,22,43 for 3 cycles, every 3 weeks) before surgery; major pathologic response (MPR) was the primary endpoint. In ICON, patients with stage IB(≥4cm)-IIIA resectable NSCLC received C before surgery. Surgically resected tumor samples underwent immune profiling via flow cytometry (n=16,13,9 for C,N,NC), immunohistochemistry (IHC;n=0,18,14), and multiplexed immunofluorescence (mIF;n=28,16,10). Treatment-associated immunomodulation and associations with therapeutic efficacy were analyzed using: 1) a shared nearest neighbors-based network we developed linking measurements across datasets; 2) MetaCyto, a specialized cytometry analysis method for identifying cell subsets by clustering.

Results

We holistically explored the immunomic data by integration across cohorts. Through hierarchical regression of the integrated data, we determined the overall effect of a given treatment controlling for the presence or absence of the other treatment.

We examined C’s effects across all cohorts controlling for N. Across all patients, regardless of MPR, C is associated with immunosuppression, increasing PD1+ T cell (CD45+CD3+) populations: regulatory (CD4+CD25+FOXP3+), helper (CD4+), and effector (CD8+) (effect size(ES):1.48,1.61,1.26;q<0.05). C also decreases proliferative (Ki67+) populations: helper and effector T cells as well as NK (CD45+CD3-CD56+) cells (ES:-1.27,-1.43;-1.36;q<0.05). In patients without MPR (i.e., non-responding patients), immunosuppression appears heightened by increased Ki67+ regulatory T cells (ES:1.86;q<0.05).

Conversely, we examined N’s effects across all cohorts controlling for C. Across all patients, regardless of MPR, N is associated with immune activation, increasing ICOS+ T cell populations: regulatory, helper, and effector (ES:1.29,1.29,1.47;q<0.05). Comparing N and NC reveals that adding C may drive exhaustion by increasing TIM3+ regulatory, helper and effector T cells (ES:1.16,1.17,1.23;q<0.05), an effect more pronounced in non-responding patients (ES:1.31,1.33,1.35;q<0.05).

Conclusions

We report the first integrated examination of the immunomodulatory effect of neoadjuvant C and N. C is associated with immunosuppression while N with immune activation; together, N appears to lessen C’s suppressive effects. Incorporation of transcriptomics into this integrated network of flow cytometry, mIF, and IHC immune profiling data is ongoing to augment translational insights for neoadjuvant chemo/immunotherapies.

280 Clinical outcomes of immunotherapy continued beyond radiographic progression in older adults with advanced non-small cell lung cancer

Background

While the clinical outcomes of immune checkpoint inhibitor (ICI) use in older adults with advanced-stage non-small cell lung cancer (NSCLC) have been described, the role of ICI use continued beyond disease progression (BDP) remains to be well defined for this population. This retrospective single-center study explored the clinical outcomes of continuing ICIs BDP among older adult patients with advanced NSCLC.

Methods

Using MD Anderson’s Gemini Lung Cancer database, we retrospectively reviewed the clinical outcomes of older adults (≥70 years) diagnosed with advanced-stage NSCLC treated with anti-PD-(L)1 monotherapy from March 2015 through April 2019 to correlate clinicopathologic features with clinical outcomes. Clinical therapy responses were evaluated by Response Evaluation Criteria in Solid Tumors, version 1.1 (RECIST v1.1). Toxicities were assessed using Common Terminology Criteria for Adverse Events (CTCAE), version 5. Patients treated BDP were defined as individuals receiving ICIs for ≥8 weeks prior to documentation of progression who subsequently remained on ICIs for ≥6 weeks.

Results

Of the 159 older adults meeting the inclusion criteria, 33 (21%) received ICIs BDP (64% male, median age 74.9 years (70.1–82.0) at the start of ICI treatment, 3 received first-line ICI therapy). Most patients were former (85%) or current (6%) smokers. 79% had adenocarcinoma histology. The median duration of immunotherapy continued BDP was 7.1 months (95% CI: 3.0–8.2). After a follow-up of 30.1 months, the median overall survival (mOS) was 31.5 months (95% CI: 16.5-not reached). Eight (24%) received local consolidative radiotherapy with a median duration of ICI BDP of 8.2 months (95% CI: 1.9–13.3). Twenty-five (76%) did not receive local consolidative therapy and achieved a median duration of ICI BDP of 4.1 months (95% CI: 2.3–7.8). Six (18%) exhibited pseudo-progression (i.e. delayed response to immunotherapy with decreased tumor burden on subsequent radiologic studies), with 4 achieving ”stable disease” as best response and 2 achieving a partial response. The median duration of immunotherapy continued beyond pseudo-progression was 11.7 months (95% CI: 7.1–35.7), and the mOS was 26.2 months (95% CI: 16.5–40.0). Patients treated with ICI BDP most commonly experienced fatigue (18%), pneumonitis (12%), rash (9%), and hypothyroidism (9%). Three patients (9%) experienced grade 3 or higher toxicities (one grade 3 arthralgias and two grade 3 pneumonitis).

Conclusions

ICI-use BDP in older adults with advanced NSCLC may benefit a subset of patients. Additionally, local consolidative therapy with radiation may offer prolonged duration of ICI treatment.

Acknowledgements

Supported by the generous philanthropic contributions to The University of Texas MD Anderson Lung Moon Shot Program and the MD Anderson Cancer Center Support Grant P30 CA01667. Special acknowledgment to the GEMINI team.

Ethics Approval

This study was approved and conducted in accordance with the institutional review board at the University of Texas MD Anderson Cancer Center; approval number (PA13-0589).

Abstract 2794: Blocking histamine receptor H1 on macrophages with anti-allergy drugs restores T-cell anti-tumor immunity

CD8+ T lymphocytes in tumors often become dysfunctional, prompting cancer immune escape and immunotherapy resistance. Restoring T-cell anti-tumor immunity remains an unmet challenge. Here, we show that histamine receptor H1 (HRH1) is highly expressed and tightly associated with T-cell dysfunction in human cancers. Histamine, the HRH1 ligand, is also increased in human and mouse tumors. HRH1 is predominantly expressed on tumor-associated macrophages (TAMs) and is activated by cancer cell-secreted histamine. The histamine/HRH1 axis in TAMs confers CD8+ T-cell dysfunction via increasing membrane localization of V-domain Ig suppressor of T cell activation (VISTA), an inhibitory immune checkpoint that promotes immunotherapy resistance. Blocking HRH1, genetically, or by anti-allergy drugs, reversed immunosuppressive TAMs, activated T-cells, and inhibited tumor growth in vivo. HRH1-targeting anti-allergy drugs more efficaciously enhanced immunotherapy response than anti-VISTA antibodies. Markedly, allergy-induced histamine also activates HRH1 on macrophages to induce T-cell dysfunction and immunotherapy resistance, which were reversed by the over-the-counter anti-allergy drug. Taken together, tumor cell-derived and allergy-released histamines activate HRH1 on TAMs to concede immunosuppression, pro-tumor function, and immunotherapy resistance, which can be negated by inexpensive and safer anti-allergy drugs.

Citation Format: Hongzhong Li, Yi Xiao, Jun Yao, Xiangliang Yuan, Xuedong Yin, Yuan Zhang, Yohei Saito, Hideo Yagita, Don Gibbons, Dihua Yu. Blocking histamine receptor H1 on macrophages with anti-allergy drugs restores T-cell anti-tumor immunity [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2794.

Abstract LB197: An SU2C-Mark Foundation Lung collaborative update: integrative genomics identifies distinct transcriptional states associated with checkpoint blockade resistance

The advent of PD-1/PD-L1 agents has transformed the therapeutic landscape of many advanced cancers, including non-small cell lung cancer (NSCLC). However, our understanding of the genomic biomarkers underlying effective treatment response remain limited. Here we provide updated results from our ongoing effort, the Stand Up To Cancer Lung (SU2C-Lung)/Mark Foundation EXTOLConsortium, a multi-institution collaboration to expand our understanding of the molecular determinants of immunotherapy response in NSCLC. Comprising a set of nearly 400 patients, this cohort enables evaluation of both genomic and transcriptomic factors associated with checkpoint blockade response. In addition to validating previously known associations including TMB and neoantigen burden, we examined transcriptional predictors associated with response. We generated a list of differentially expressed genes with respect to best overall response (BOR), and performed dimensionality reduction using semi-supervised Bayesian Non-Negative Factorization (ssBNMF). We identified 3 distinct clusters with strong sample membership. Characterization of these subtypes revealed varying levels of immune infiltrate, histologic composition, and response rates to checkpoint blockade. Of these three subtypes, two were associated with low response rates to PD-1/PD-L1 blockade, suggesting the existence of distinct avenues toward resistance. To further characterize these transcriptional subtypes, we used ssBNMF marker genes to classify publicly available NSCLC samples from The Cancer Genome Atlas (TCGA), along with gene expression from a smaller cohort of large-cell neuroendocrine (LCNE) samples. Histologic composition showed good concordance with our SU2C samples, and redemonstrated observations within our smaller SU2C cohort of distinct immuno-suppressive and immuno-depleted milieus associated with resistance.

Citation Format: Monica B. Arniella, Arvind Ravi, Justin Gainor, Chip Stewart, Sam Freeman, Mark Awad, Patrick Forde, Valsamo Anagnostou, Brian Henick, Jonathan W. Riess, Don Gibbons, Nathan Pennell, Vamsidhar Velcheti, Ignaty Leshchiner, Jaegil Kim, Subba Digumarthy, Mari Mino-Kenudson, John Heymach, Nir Hacohen, Naiyer Rizvi, Roy Herbst, Victor E. Velculescu, Julie Brahmer, Kurt Schalper, Pasi Jänne, Jedd Wolchok, Alice Shaw, Gad Getz, Matthew D. Hellman. An SU2C-Mark Foundation Lung collaborative update: integrative genomics identifies distinct transcriptional states associated with checkpoint blockade resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB197.

277 Combined neoadjuvant chemo-immunotherapy therapy achieves superior downstaging of resectable non-small cell lung cancer as compared to chemotherapy, mono or dual immunotherapy

Background

Tumor and nodal downstaging following neoadjuvant therapy in resectable non-small cell lung cancer (NSCLC) are important markers of therapeutic response associated with favorable prognosis. We studied the impact of four different systemic neoadjuvant therapies on tumor, nodal and overall pathological downstaging of surgically resectable I-IIIA NSCLC (AJCC 7th edition).

Methods

Our study cohorts consisted of NSCLC patients treated with three cycles of neoadjuvant platinum doublet chemotherapy from 2001–2012 (N=302, 84%), and patients treated on the NEOSTAR study (NCT03158129) who received neoadjuvant nivolumab (N=21,6%), nivolumab plus ipilimumab (N=16, 4%), or platinum doublet chemotherapy plus nivolumab (N=22, 6%). Clinical and pathological (yp) T and N staging were evaluated for downstaging and upstaging; differences were assessed using Fisher’s exact test.

Results

Following neoadjuvant platinum doublet chemotherapy, nivolumab, nivolumab plus ipilimumab and platinum doublet chemotherapy plus nivolumab, the rates of clinical-to-pathological ypT downstaging were 26% (N=79), 29% (N=6), 38% (N=6) and 59% (N=13), respectively, p =0.012 (table 1). The rates of clinical-to-pathological ypN downstaging in patients with clinical N1 or N2 disease with each therapy were 55% (N=96), 50% (N=3), 50% (N=2), and 42% (N=5) respectively, p =0.862. Overall clinical-to-pathological (ypT and/or ypN) downstaging rates were 38% (N=114), 38% (N=8), 38% (N=6), and 68% (N=15) respectively, p=0.048. The proportions of patients being overall upstaged following each therapy were 28% (N=85), 38% (N=8), 38% (N=6) and 14% (N=3), respectively, p=0.251. These results suggest superior downstaging effect and clinically meaningful lower upstaging probability of combined platinum doublet chemotherapy plus nivolumab as compared to other neoadjuvant regimens.

Abstract 277 Table 1

Response to Chemotherapy, Immunotherapy, and Combination Therapy

Conclusions

The combination of neoadjuvant platinum doublet chemotherapy with nivolumab achieves the most robust tumor and overall pathological downstaging and decreases the probability of upstaging at surgery. Whether the overall downstaging effect results in improved survival will be determined with longer follow-up, in conjunction with results from ongoing phase III neoadjuvant chemo-immunotherapy trials.

Trial Registration

NCT03158129

Ethics Approval

This study was approved by the University of Texas MD Anderson Institutional Review Board with a waiver of informed consent, protocol 2020-0337.

Abstract 5902: Integrative genomic analysis of checkpoint blockade in lung cancer: A multi-institution SU2C collaborative

PD-1/PD-L1 checkpoint blockade has been a landmark advance for many patients suffering from advanced non-small cell lung cancer (NSCLC). However, detailed biomarkers of response beyond tumor mutational burden (TMB) are still poorly understood. As part of the effort to elucidate these additional signatures, we describe our progress on the Stand Up to Cancer Lung (SU2C-Lung) cohort. Initial characterization of exomes recapitulates mutational and copy number profiles seen in The Cancer Genome Atlas (TCGA) project. To better define expression subtypes using RNA sequencing, we performed non-negative matrix factorization (NMF) across an aggregated set of publicly available NSCLC expression data (including adenocarcinoma, squamous cell carcinoma, and large cell neuroendocrine histologies), and demonstrate good concordance in the SU2C-Lung cohort between this expression-based classifier and clinically annotated histology. To gain further insight into how immune cell infiltrates vary across our cohort, we additionally tested two common deconvolution algorithms, EPIC and CIBERSORT. While these two methods agree for some prominent cell types, such as B cells and CD4 T cells, discrepancies in minor infiltrating components such as NK cells may suggest a limit to the inference of rare subpopulations from bulk sequencing data.Finally, we describe a novel approach for determining single-gene predictors of response. Using the method, which is based on comparison of top single transcriptional features identified from random bootstraps of the full cohort as compared to a set of background shuffles, we are able to show that we remain powered for discovery of RNA response biomarkers despite the typically burdensome toll of multiple hypothesis correction at genome wide scale.

Acknowledgment: Supported by Stand Up To Cancer-American Cancer Society Lung Cancer Dream Team Translational Research Grant SU2C-AACR-DT17-15.

Citation Format: Monica Arniella, Arvind Ravi, Chip Stewart, Sam Freeman, Mark Awad, Patrick Forde, Valsamo Anagnostou, Brian Henick, Jonathan Riess, Don Gibbons, Nathan Pennell, Vamsidhar Velcheti, Ignaty Leshchiner, Jaegil Kim, Subba Digumarthy, Mari Mino-Kenudson, John Heymach, Nir Hacohen, Naiyer Rizvi, Roy Herbst, Victor Velculescu, Julie Brahmer, Kurt Schalper, Pasi Jänne, Jedd Wolchok, Alice Shaw, Justin Gainor, Matthew Hellmann, Gad Getz. Integrative genomic analysis of checkpoint blockade in lung cancer: A multi-institution SU2C collaborative [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 5902.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Suppressed immune microenvironment and repertoire in brain metastases from patients with resected non-small-cell lung cancer

BACKGROUND

The tumor immune microenvironment (TIME) of lung cancer brain metastasis is largely unexplored. We carried out immune profiling and sequencing analysis of paired resected primary tumors and brain metastases of non-small-cell lung carcinoma (NSCLC).

PATIENTS AND METHODS

TIME profiling of archival formalin-fixed and paraffin-embedded specimens of paired primary tumors and brain metastases from 39 patients with surgically resected NSCLCs was carried out using a 770 immune gene expression panel and by T-cell receptor beta repertoire (TCRβ) sequencing. Immunohistochemistry was carried out for validation. Targeted sequencing was carried out to catalog hot spot mutations in cancer genes.

RESULTS

Somatic hot spot mutations were mostly shared between both tumor sites (28/39 patients; 71%). We identified 161 differentially expressed genes, indicating inhibition of dendritic cell maturation, Th1, and leukocyte extravasation signaling pathways, in brain metastases compared with primary tumors (P < 0.01). The proinflammatory cell adhesion molecule vascular cell adhesion protein 1 was significantly suppressed in brain metastases compared with primary tumors. Brain metastases exhibited lower T cell and elevated macrophage infiltration compared with primary tumors (P < 0.001). T-cell clones were expanded in 64% of brain metastases compared with their corresponding primary tumors. Furthermore, while TCR repertoires were largely shared between paired brain metastases and primary tumors, T-cell densities were sparse in the metastases.

CONCLUSION

We present findings that suggest that the TIME in brain metastases from NSCLC is immunosuppressed and comprises immune phenotypes (e.g. immunosuppressive tumor-associated macrophages) that may help guide immunotherapeutic strategies for NSCLC brain metastases.

Abstract 5028: Characterization of the tumor immune microenvironment in treatment-naïve EGFR-mutant NSCLC uncovers a low IFN-gamma suppressive immune phenotype

Background: Although immune checkpoint blockade has been successfully utilized in treating patients with non-small cell lung cancer (NSCLC), the benefit of immunotherapy for patients with advanced EGFR-mutant (EGFRm) NSCLC has been limited. Data from IMpower150 trial’s subgroup analysis suggests modulation of the tumor immune microenvironment (TME) with antiangiogenic agents and chemotherapy might enhance response to anti-PD-1/PD-L1 blockade in EGFRm lung cancers. We aim to gain a deep understanding of EGFRm NSCLC TME as the first step to make EGFRm amenable to immune therapy.

Methods: We queried two cohorts of resected stage I-III lung adenocarcinomas: PROSPECT (94 tumors) and Immune Genomic Profiling of NSCLC (ICON, 76 tumors). In the PROSPECT cohort (14 EGFRm vs 80 WT), we compared 10 immune markers by IHC (PD-L1, PD-1, CD3, CD4, CD8, CD45RO, CD57, CD68, FoxP3 and Granzyme B) and 44 immune regulator genes’ expression levels and pathway signatures from microarray data. We subsequently validated the observation of differentially expressed genes in the ICON cohort (15 EGFRm vs 61 WT) using IF, RNAseq and WES.

Results: In the PROSPECT cohort, lower PD-L1 (2.2 vs 10.4 H-score, p&lt;0.01) and lower GzmB (212 vs. 358 counts/mm2, p=0.02) were observed in the EGFRm compared to WT tumors. This is validated in the ICON cohort, showing lower PD-L1 expression (0.18% vs 7.28% p=0.05) and lower TMB (1.8 vs 9.0 mut/Mb, p&lt;0.01) in EGFRm compared to WT tumors. IFN-gamma gene expression (3.89 vs 4.71 p=0.03 in PROSPECT) and signatures were low in the EGFRm tumors, suggesting a suppressive tumor microenvironment. Different than some prior reports, we found CD8+ T cells were not significantly different in EGFRm vs. WT groups. Among known immune regulators, TGFbeta was higher in the EGFRm tumors in the PROSPECT cohort, but not in the ICON cohort. Other known immune regulators, including CTLA4, LAG3, TIM3, TIGIT, IL6 and VEGFA were not differentially expressed.

Conclusion: Our analysis showed that EGFR-mutant NSCLCs demonstrate a PD-L1 low, GzmB low, IFN-gamma low immune phenotype, suggesting a suppressive tumor microenvironment. We found that the CD8+ T cells were present in the tumor, but likely suppressed functionally by the negative regulators in the TME. These results direct future analysis of suppressive immune cell populations (CD4+ subpopulation, macrophages and dendritic cells) in EGFRm lung cancers, and represent an initial step for rationale combination of immune therapy to modulate the suppressed TME, which might lead to enhanced treatment efficacy to benefit patients with EGFR-mutant lung cancers.

Citation Format: Xiuning Le, Marcelo V. Negrao, Alexandre Reuben, Won-Chul Lee, Edwin Parra, Jun Li, Tatiana Karpinets, Carmen Behrens, Boris Sepesi, Ara Vaporiciyan, Jack Roth, Cara Haymaker, Emily Roarty, Jianhua Zhang, Chantale Bernatchez, Jianjun Zhang, Ignacio Wistuba, Don Gibbons, John Heymach. Characterization of the tumor immune microenvironment in treatment-naïve EGFR-mutant NSCLC uncovers a low IFN-gamma suppressive immune phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 5028.

In vitro co-culture and ex vivo organ culture assessment of primed and cryopreserved stromal cell microcapsules for intervertebral disc regeneration

Priming towards a discogenic phenotype and subsequent cryopreservation of microencapsulated bone marrow stromal cells (BMSCs) may offer an attractive therapeutic approach for disc repair. It potentially obviates the need for in vivo administration of exogenous growth factors, otherwise required to promote matrix synthesis, in addition to providing 'off-the-shelf' availability. Cryopreserved and primed BMSC microcapsules were evaluated in an in vitro surrogate co-culture model system with nucleus pulposus (NP) cells under intervertebral disc (IVD)-like culture conditions and in an ex vivo bovine organ culture disc model. BMSCs were microencapsulated in alginate microcapsules and primed for 14 d with transforming growth factor beta-3 (TGF-β3) under low oxygen conditions prior to cryopreservation. For the in vitro phase, BMSC microcapsules (unprimed or primed) were cultured for 28 d in a surrogate co-culture model system mimicking that of the IVD. For the ex vivo phase, microcapsules (unprimed or primed) were injected into the NP of bovine discs that underwent nucleotomy. In vitro results revealed that although NP cells produced significantly more matrix components in co-culture with BMSC microcapsules regardless of the differentiation state, unprimed microcapsules were inadequate at synthesising matrix as compared to primed microcapsules. However, this difference was diminished when evaluated in the ex vivo organ culture model,withboth unprimed and primed BMSC microcapsules accumulating large amounts of sulphated glycosaminoglycan (sGAG) and collagen and filling the defect cavity. Both models demonstrated that cryopreservation of BMSC microcapsules may offer a feasible strategy for predesigned delivery through cryobanking for on-demand regeneration of the IVD.

Abstract A059: Tackling the tumor microenvironment with CD38 blockade to enhance cancer immunotherapy

The single agent or the combination of anti-PD-1, anti-PD-L1, and anti-CTLA-4 is an effective strategy that is being clinically explored to treat a variety of cancer types. Some patients display primary resistance to the treatment, while others relapse after treatment. Resistance is a major issue that needs to be addressed. Using multiple immunocompetent syngeneic and K-rasLA1/+p53R172HΔg/+ spontaneous animal models of lung cancer, we have explored the mechanisms of resistance to treatments by evaluating the molecular and cellular immune profiles of the tumor microenvironment. We observed that tumor-bearing mice treated with PD-1/PD-L1 blocking antibodies developed resistance through the up-regulation of CD38. We also observed this in the combination therapy of anti-PD-1 and anti-CTLA-4, suggesting that CD38 is a major mechanism of resistance to immune checkpoint inhibitors. In vitro and in vivo studies demonstrated that CD38 impacted CD8+ T-cell function via adenosine receptor signaling and dendritic cell-mediated B7 signaling. Antibody-mediated cell depletion assays were conducted to validate the mechanisms. To determine the applicability to patients, we analyzed 793 lung cancer patients’ specimens with immunohistochemistry staining and assessed biomarker relationships in multiple large independent patient databases (~1,900 tumors). Pathologic analysis revealed positive immunohistochemical staining for CD38 on tumor cells in 15-23% of cases, and bioinformatic analyses revealed a strong correlation between CD38 expression and the immune signature. Lastly, targeting CD38 abolished the treatment resistance by modulating the adenosine levels and thereby enhancing the effector immune cell infiltrates into the tumor microenvironment. Based on our study, CD38 blockade improves the efficacy of single-agent anti-PD-1/PD-L1, or with anti-CTLA-4 combination in lung cancer. CD38 could potentially serve as a novel biomarker of resistance for immune checkpoint inhibition. The data from this study provide a unique target, biomarker, and therapeutic strategy that can be translated into the clinical practice.

Citation Format: Limo Chen, Lixia Diao, Xiaohui Yi, Bertha Leticia Rodriguez, Yanli Li, Pamela Villalobos, Tina Cascone, Xi Liu, Lin Tan, Philip Lorenzi, Jared Fradette, David Peng, Ferdinandos Skoulidis, Youhong Fan, Jaime Rodriguez-Canales, Vassiliki Papadimitrakopoulou, Ethan Dmitrovsky, Lauren A Byers, Jing Wang, Ignasio Wistuba, Jim Heymach, Don Gibbons. Tackling the tumor microenvironment with CD38 blockade to enhance cancer immunotherapy [abstract]. In: Proceedings of the Fourth CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; Sept 30-Oct 3, 2018; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2019;7(2 Suppl):Abstract nr A059.

Operative Management of Perinatal Lumbar Disc Herniation and Cauda Equina Syndrome: A Case Series

Introduction Perinatal lumbar discectomy for lumbar disc herniation or cauda equina syndrome is a rare clinical scenario. This case series outlines the surgical management of this clinical scenario at a national tertiary referral centre over a 10-year period Methods A retrospective review of all females who underwent discectomy / decompression for lumbar disc herniation or cauda equina syndrome in the perinatal period at a national tertiary referral centre for spine surgery over a 10-year period between January 2008 to December 2017. Results 6 cases required surgical intervention. All patients were successfully managed with surgical decompressive procedures and recovered well in the postoperative period without complication. Conclusions The principles of management remain the same in the pregnant and non-pregnant populations, although treatment options are complicated by the desire to avoid risk to the developing foetus. Surgical intervention is safe to both mother and baby and if performed promptly is associated with an excellent functional outcome.

Effects of CDX2 on prognosis and chemotherapy responsiveness in mismatch repair-deficient colorectal cancer

Background

Caudal‐related homeobox transcription factor 2 (CDX2) is an intestine‐specific transcription factor implicated in tumour differentiation, proliferation, cell adhesion and migration. Negative CDX2 status (CDX2−) is associated with worse prognosis in colorectal cancer and may identify high‐risk stage II disease that benefits from adjuvant chemotherapy. This observational study investigated whether CDX2− is associated with prognosis or response to chemotherapy in the mismatch repair‐deficient (dMMR) phenotype of colorectal cancer.

Methods

Patients with resectable dMMR colorectal cancer were eligible for inclusion. The prognostic and predictive value of CDX2 expression on the presence of lymph node metastasis (LNM) and survival was investigated. CDX2 status was determined via immunohistochemistry using the Leica Bond™ CDX2 (clone EP25) ready‐to‐use primary antibody.

Results

Some 235 of 238 consecutive dMMR tumours were assessed for CDX2 status. CDX2− was observed in 15·7 per cent of colorectal cancer. Interobserver agreement was excellent (κ = 0·863; P < 0·001). CDX2− was significantly associated with female sex, increased size, advanced stage, worse conventional and poorly differentiated cluster (PDC) grade, mucinous morphology, perineural and lymphovascular invasion, and pN status (all P ≤ 0·038). CDX2− was not associated with LNM or survival in multivariable analysis. Independent predictors of LNM were PDC grade (odds ratio (OR) 4·12, 95 per cent c.i. 1·76 to 9·63; P = 0·001) and extramural venous invasion (OR 3·79, 1·62 to 8·85; P = 0·002). Budding (hazard ratio (HR) 2·79, 95 per cent c.i. 1·60 to 4·87; P < 0·001), pT status (HR 3·59, 1·29 to 10·01; P = 0·015) and adjuvant chemotherapy (HR 2·07, 1·15 to 3·74; P = 0·016) were independently associated with worse disease‐free survival.

Conclusion

CDX2− does not confer a worse prognosis in the dMMR phenotype of colorectal cancer. The MMR status of patients with colorectal cancer should be determined before assessing CDX2 status.

Immunohistochemical and Image Analysis-Based Study Shows That Several Immune Checkpoints are Co-expressed in Non-Small Cell Lung Carcinoma Tumors

INTRODUCTION

The understanding of immune checkpoint molecules' co-expression in non-small cell lung carcinoma (NCLC) is important to potentially design combinatorial immunotherapy approaches.

METHODS

We studied 225 formalin-fixed, paraffin-embedded tumor tissues from stage I-III NCLCs - 142 adenocarcinomas (ADCs) and 83 squamous cell carcinomas (SCCs) - placed in tissue microarrays. Nine immune checkpoint markers were evaluated; four (programmed death ligand 1 [PD-L1], B7-H3, B7-H4, and indoleamine 2,3-dioxygenase 1 [IDO-1]) expressed predominantly in malignant cells (MCs) and five (inducible T cell costimulator, V-set immunoregulatory receptor, T-cell immunoglobulin mucin family member 3, lymphocyte activating 3, and OX40) expressed mostly in stromal tumor-associated inflammatory cells (TAICs). All markers were examined using a quantitative image analysis and correlated with clinicopathologic features, TAICs, and molecular characteristics.

RESULTS

Using above the median value as positive expression in MCs and high density of TAICs expressing those markers, we identified higher expression of immune checkpoints in SCC than ADC. Common simultaneous expression by MCs was PD-L1 + B7-H3 + IDO-1 in ADC and PD-L1 + B7-H3, or B7-H3 + B7-H4, in SCC. TAICs expressing checkpoint were significantly higher in current smokers than in never smokers. Almost all the immune checkpoint markers showed positive correlation with TAICs expressing inflammatory cell markers. KRAS-mutant ADC specimens showed higher expression of PD-L1 in MCs and of B7-H3, T-cell immunoglobulin mucin family member 3, and IDO-1 in TAICs than wild type. Kaplan-Meier survival curves showed worse prognosis in ADC patients with higher B7-H4 expression by MCs.

CONCLUSIONS

We found frequent immunohistochemical co-expression of immune checkpoints in surgically resected NCLC tumors and correlated with tumor histology, smoking history, tumor size, and the density of inflammatory cells and tumor mutational status.

Validation of multiplex immunofluorescence panels using multispectral microscopy for immune-profiling of formalin-fixed and paraffin-embedded human tumor tissues

Immune-profiling is becoming an important tool to identify predictive markers for the response to immunotherapy. Our goal was to validate multiplex immunofluorescence (mIF) panels to apply to formalin-fixed and paraffin-embedded tissues using a set of immune marker antibodies, with the Opal™ 7 color Kit (PerkinElmer) in the same tissue section. We validated and we described two panels aiming to characterize the expression of PD-L1, PD-1, and subsets of tumor associated immune cells. Panel 1 included pancytokeratin (AE1/AE3), PD-L1, CD4, CD8, CD3, CD68, and DAPI, and Panel 2 included pancytokeratin, PD-1, CD45RO, granzyme B, CD57, FOXP3, and DAPI. After all primary antibodies were tested in positive and negative controls by immunohistochemistry and uniplex IF, panels were developed and simultaneous marker expressions were quantified using the Vectra 3.0™ multispectral microscopy and image analysis InForm™ 2.2.1 software (PerkinElmer).These two mIF panels demonstrated specific co-localization in different cells that can identify the expression of PD-L1 in malignant cells and macrophages, and different T-cell subpopulations. This mIF methodology can be an invaluable tool for tumor tissue immune-profiling to allow multiple targets in the same tissue section and we provide that is accurate and reproducible method when is performed carefully under pathologist supervision.

Abstract 567: CD38 blockade overcomes the immune resistance to anti-PD-L1 therapy by boosting CD8 T cell response

Although strategies incorporating immune checkpoint inhibition, e.g. PD-1/PD-L1 blockade, are achieving unprecedented successes and increasingly becoming incorporated into standard of care regimens for cancer patients, high rates of resistance still limit the potential efficacy. Therapeutic improvement requires a thorough understanding of the biological process of resistance. To date there have been few studies reporting mechanisms of resistance to PD-L1 blockade. We have explored the resistance mechanisms to functional PD-L1 loss in preclinical lung cancer models by using pharmacological and genetic approaches (PD-L1 blocking antibody treatment or CRISPR/Cas9-mediated deletion of PD-L1 on tumor cells). The molecular and immune profiles of the tumor microenvironment were evaluated in mutant K-ras/p53 (KP) GEM lung cancer models and multiple immunocompetent syngeneic models (both KP and Lewis lung cancer). Additionally, to determine the applicability of the results to patients with lung cancer, we analyzed 259 patient tumor specimens with IHC staining and evaluated the immune markers in TCGA datasets (adenocarcinoma and squamous) and the MD Anderson PROSPECT dataset. We observed that lung tumors gained resistance to anti-PD-L1 antibody treatment over time, and that the up-regulation of CD38 on tumor cells accounted for the treatment resistance. We also observed the same resistance mechanism caused by CD38 up-regulation in PD-L1 KO mice bearing PD-L1 KO Lewis lung tumors generated with the CRISPR/Cas9 system. Manipulation of CD38 on a panel of lung cancer cell lines, demonstrated that CD38 inhibits CD8+ T cell proliferation, antitumor cytokine secretion, and tumor cell killing capability in vitro and in vivo. Furthermore, to test whether CD38 blockade might be therapeutically efficacious to counter anti-PD-L1 resistance, we applied the combination therapy of anti-CD38 and anti-PD-L1 in lung cancer animal models and demonstrated dramatic therapeutic benefit on primary tumor growth and metastasis. Bioinformatic analyses of the patient tumor databases revealed a strong correlation between CD38 expression and an immune suppressive inflammatory signature. Finally, in 259 lung cancer specimens, 18.5% of cases exhibited positive staining for CD38 on tumor cells. Based upon our studies, we conclude that the up-regulation of CD38 on tumor cells is a major mechanism of resistance to anti-PD-L1 therapy, and that CD38 is a novel immune checkpoint that inhibits CD8+ T cell function. The blockade of CD38 and PD-L1 is a rational combination to prevent immune resistance and increase the response rate for lung cancer patients.

Citation Format: Limo Chen, Lixia Diao, Yongbin Yang, Xiaohui Yi, Jaime Rodriguez, Youhong Fan, Leticia Rodriguez, Jared Fradette, Christin Ungewiss, Jonothan Roybal, Jingfen Zhu, Jing Wang, Lauren Byers, Stephen Ullrich, Ignacio Wistuba, John Heymach, Xiao-Feng Qin, Don Gibbons. CD38 blockade overcomes the immune resistance to anti-PD-L1 therapy by boosting CD8 T cell response [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 567. doi:10.1158/1538-7445.AM2017-567

Abstract 2934: Neoadjuvant chemotherapy influence changes of the immune response in non-small cell lung carcinomas immune response in non-small cell lung carcinomas

Background: The clinical efficacy observed with PD-1/PD-L1 inhibitors in non-small cell lung carcinoma (NSCLC) has prompted to characterize the immune response in lung tumors treated with chemotherapy. The aim of this study was to determine the changes of the immune microenvironment in surgically resected NSCLCs from patients who received and did not receive neo-adjuvant chemotherapy.

Methods: We studied formalin-fixed and paraffin embedded (FFPE) tumor tissues from 112 stage II/III resected NSCLC, including 61 chemotherapy-naïve (adenocarcinoma, ADC=33; squamous cell carcinoma, SCC=28) and 51 chemotherapy-treated (ADC=31; SCC=20) tumors. mIF was performed using the Opal 7-color fIHC Kit™, scanning in the Vectra™ multispectral microscope and analyzed using the inForm™ software (Perkin Elmer, Waltham, MA). The markers studied were grouped in two 6-antibody panels: Panel 1, AE1/AE3 pancytokeratins, PD-L1 (clone E1L3N), CD3, CD4, CD8 and CD68; and Panel 2, AE1/AE3, PD1, Granzyme B, FOXP3, CD45RO and CD57.

Results: Positive PD-L1 expression (&gt;5%) in malignant cells (MCs) was detected in 48% (n=53/112) of NSCLCs. Overall, chemotherapy-treated tumors showed significantly higher percentages of MCs expressing PD-L1 (median, 19.52%) than chemotherapy-naïve cases (median, 1.54%; P=0.008). Higher densities of lymphocytes expressing CD3+ (P=0.021), CD4+ (P=0.05), CD57 (P&lt;0.001), CD45RO+ (P=0.019), and PD-1 (P=0.016) were detected in chemotherapy-treated NSCLCs compared with chemo-naïve tumors. In contrast, lower densities of FOXP3+ regulatory T cells and CD68+ macrophages but not statistical significant were detected in chemotherapy-naïve tumors when compared with chemotherapy-treated cases. Following chemotherapy ADCs exhibited significantly higher levels of CD57+ (P=0.008) and high density of PD-1 expressing by CD45RO+ cells (P=0.016) than chemotherapy-naïve tumors. Chemotherapy-treated SCCs demonstrated higher density of TAMs CD68+, CD57+,CD45RO+ and PD-1 cells than chemotherapy-naïve tumors (P&lt;0.05). In chemotherapy-treated cancers, lower levels of CD4+ helper T cells was associated with worse overall survival (OS; P=0.04) in univariate analysis. In chemotherapy-treated ADC patients, lower levels of CD68-positive (P=0.010) and higher levels of FOXP3-positive cells correlated with worse OS (P=0.044).

Conclusions: Neo-adjuvant chemotherapy-treated NSCLCs exhibited higher levels of PD-L1 expression and T cell subsets regulation compared to chemotherapy-naïve tumors, suggesting that chemotherapy activates specific immune response mechanisms in lung cancer. These results provide an inclination towards the design of clinical trials combining neo-adjuvant chemotherapy and immunotherapy prior to surgical resection of locally advanced NSCLC. (Supported by CPRIT MIRA and UT Lung SPORE grants, and MD Anderson Moon Shot Program).

Citation Format: Edwin Roger Cuentas, Carmen Behrens, Jaime Rodriguez-Canales, Mei Jiang, Apar Pataer, Arelene Correa, Stephen Swisher, Boris Sepesi, Annikka Weissferdt, Neda Kalhor, Jiexin Zhang, Jack Lee, John Heymach, Cesar Moran, Jianjun Zhang, Don Gibbons, Ignacio Wistuba. Neoadjuvant chemotherapy influence changes of the immune response in non-small cell lung carcinomas immune response in non-small cell lung carcinomas [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2934. doi:10.1158/1538-7445.AM2017-2934

The lymph node ratio does not provide additional prognostic information compared with the N1/N2 classification in Stage III colon cancer

AIM

The ratio of positive nodes to total nodes, the lymph node ratio (LNR), is a proposed alternative to the current N1/N2 classification of nodal disease. The true clinical benefit of adopting the LNR, however, has not been definitively demonstrated. This study compared the LNR with the current N1/N2 classification of Stage III colon cancer.

METHOD

Patients with Stage III colon cancer were identified from a prospectively maintained database (1996-2012). The specificity and sensitivity of the N1/N2 classification in the prediction of overall survival were determined using R. A cut-off point for the LNR was determined by setting the specificity the same as for the N1/N2 classification. The sensitivity of the two methods was then compared, and bootstrapping 1000-fold was performed. This was then repeated for disease-specific survival.

RESULTS

The specificity and sensitivity of the N1/N2 classification in predicting 3-year overall survival in this cohort (n = 402) was 62.2% and 52.1%, respectively. The cut-off point for the LNR was determined to be 0.27 for these data. On comparing LNR with the N1/N2 classification showed that for a given specificity, the LNR did not provide a statistically significant improvement in sensitivity (52.8% vs 52.1%, P = 0.31). For disease-specific death at 3 years, the specificity and sensitivity were 60.8% and 54.6%, respectively. The LNR did not provide a statistically significant improvement (55.4% vs 54.6%, P = 0.44).

CONCLUSION

Both the N1/N2 system and the LNR predict survival in colon cancer, but both have low specificity and sensitivity. The LNR does not provide additional prognostic value to current staging for overall or disease-specific survival for a given cut-off point.