Improve Immunotherapy Efficacy Research Articles

ARID1A-Deficient Tumors Acquire Immunogenic Neoantigens during the Development of Resistance to Targeted Therapy.

Neoantigen-based immunotherapy is an attractive potential treatment for previously intractable tumors. To effectively broaden the application of this approach, stringent biomarkers are crucial to identify responsive patients. ARID1A, a frequently mutated subunit of SWI/SNF chromatin remodeling complex, has been reported to determine tumor immunogenicity in some cohorts; however, mutations and deletions of ARID1A are not always linked to clinical responses to immunotherapy. In this study, we investigated immunotherapeutic responses based on ARID1A status in targeted therapy-resistant cancers. Mouse and human BRAFV600E melanomas with or without ARID1A expression were transformed into resistant to vemurafenib, an FDA-approved specific BRAFV600E inhibitor. Anti-PD-1 antibody treatment enhanced antitumor immune responses in vemurafenib-resistant ARID1A-deficient tumors but not in ARID1A-intact tumors or vemurafenib-sensitive ARID1A-deficient tumors. Neoantigens derived from accumulated somatic mutations during vemurafenib resistance were highly expressed in ARID1A-deficient tumors and promoted tumor immunogenicity. Furthermore, the newly generated neoantigens could be utilized as immunotherapeutic targets by vaccines. Finally, targeted therapy resistance-specific neoantigen in experimental human melanoma cells lacking ARID1A were validated to elicit T-cell receptor responses. Collectively, the classification of ARID1A-mutated tumors based on vemurafenib resistance as an additional indicator of immunotherapy response will enable a more accurate prediction to guide cancer treatment. Furthermore, the neoantigens that emerge with therapy resistance can be promising therapeutic targets for refractory tumors. Significance: Chemotherapy resistance promotes the acquisition of immunogenic neoantigens in ARID1A-deficient tumors that confer sensitivity to immune checkpoint blockade and can be utilized for developing antitumor vaccines, providing strategies to improve immunotherapy efficacy.

Impact of concomitant H1 antihistamine administered during initiation of immune checkpoint inhibitor therapy on survival outcome and safety in patients with advanced primary lung cancer.

e20532 Background: Antihistamines alleviate the side effects of antitumor drugs and have some antitumor effects. However, they have rarely been tested in combination with other antitumor therapies, especially immunotherapy. Methods: We compared the progression-free survival (PFS) and overall survival (OS) of patients with advanced primary lung cancer (stage III or IV) receiving immunotherapy with H1 antihistamine diphenhydramine alone (n = 40) or in combination with H2 antihistamine cimetidine (n = 69) [experimental group] to those receiving immunotherapy alone (n = 75) or with a H2 antihistamine cimetidine (n = 27) [control group]. We used the inverse probability of treatment weights (IPTW) to balance the two groups. Kaplan Meier curves were used to compare OS and PFS between the two groups. Cox regression analyses were used to describe the association between patient characteristics and OS or PFS. Results: The experimental group comprised 109 patients, while the control group comprised 102. The median PFS (mPFS) was 12.7 months in the experimental group and 4.3 months in the control group (HR 0.46, 95% CI 0.35-0.63, P < 0.001). The median OS (mOS) was 32.8 months in the experimental group and 18.1 months in the control group (HR 0.63, 95% CI 0.44-0.91, P = 0.038). In the experimental group, patients treated with only H1 antihistamine had longer mPFS and mOS as compared with those who received H1 plus H2 antihistamines (mPFS: 18.0 months vs. 6.8 months, HR 1.40, 95% CI 0.26-0.63, P < 0.001; mOS: not reached vs. 26.6 months, HR 0.55, 95% CI 0.32-0.94, P = 0.030). In the control group, patients who received no antihistamine had longer mPFS and mOS compared to those who received only H2 antihistamines (mPFS: 5.8 months vs. 4.1 months, HR 0.44, 95% CI 0.29-0.67, P < 0.001; mOS: 25.5 vs. 16.9 months, HR 0.61, 95% CI 0.37-1.00, P = 0.049). After multivariate analyses, H1 antihistamine was the independent good prognostic factor for PFS and OS (PFS: HR 0.44, 95% CI 0.31-0.65, P < 0.001; OS: HR 0.62, 95% CI 0.39-0.99, P = 0.047). Conversely, H2 antihistamine was the independent poor prognostic factor for PFS and OS (PFS: HR 2.44, 95% CI 1.67-3.57, P < 0.001; OS: HR 2.38, 95% CI 1.49-3.70, P < 0.001). After IPTW, the rate of any grade of irAEs in the experimental group was 52.4%, while that of the control group was 69.2% ( P = 0.015), including 4.5% for irAEs grades ≥3 in the experimental group and 25.9% for irAEs grades ≥3 in the control group ( P = 0.003). Conclusions: Concomitant H1 antihistamines can not only improve immunotherapy efficacy but also reduce irAEs. Concomitant use of H2 antihistamines may shorten PFS and OS time.

Abstract PO2-25-01: Tumor Derived Chitinase-3 like 1 Induces Neutrophil Extracellular Traps that Promote T cell Exclusion and Resistance to Immunotherapies in Breast Cancer

Abstract Breast cancer remains the most prevalent cancer and a major cause of mortality affecting women worldwide. Chemotherapy along with radiation and surgery have long been the standard of care for breast cancer patients. However, devastating side effects, resistance to treatments and relapse are major concerns for patients and physicians. With the rise of immunotherapies as a treatment option for various cancers, there is a critical need to understand the mechanisms through which cancers evade the immune system. Targeting such mechanisms holds the key to improve patient response to immunotherapy, especially in breast cancer where efficacy rates remain low. In a subset of poor outcome Triple Negative Breast Cancers, cytotoxic T cells are excluded from the tumor nest and restricted to the surrounding stroma, a phenomenon known as stromal restriction. Our data from genetically engineered mouse models and human tumors identified that the secreted cytokine Chitinase-3 like 1 (Chi3l1) promotes stromal restriction of T cells in several tumor types including breast, lung and colon. Chi3l1 ablation in pre-clinical models of breast cancer results in increased T cell infiltration into the tumor nest which delayed mammary tumorigenesis and improved response to immunotherapy. We further demonstrate that Chi3l1 promotes T cell exclusion through the direct induction and deposition of neutrophil extracellular traps (NETs) which form a barrier that restricts T cell entry. Neutrophil depletion or pharmacological disruption of NET formation abrogates Chi3l1-induced T cell exclusion and histologically phenocopies Chi3l1 ablation. Thus, our results indicate that Chi3l1 is a major immunosuppressive cytokine that promotes breast cancer progression by inducing NET formation and inhibiting T cell infiltration. Given the importance of T cell infiltration in immune elimination of nascent tumors, the future targeting of Chi3l1 should improve immunotherapy efficacy and outcomes in patients with tumors characterized by a T cell excluded microenvironment. Citation Format: Tarek Taifour, Sherif Samer Attalla, Dongmei Zuo, Yu Gu, Virginie Sanguin-Gendreau, Hailey Dall-Proud, Emilie Solymoss, Tung Bui, Hellen Kuasne, Vasilios Papavasiliou, Chun Geun Lee, Suchitra Kamle, Peter Siegel, Jack Elias, Morag Park, William Muller. Tumor Derived Chitinase-3 like 1 Induces Neutrophil Extracellular Traps that Promote T cell Exclusion and Resistance to Immunotherapies in Breast Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO2-25-01.

The double life of a chemotherapy drug: Immunomodulatory functions of gemcitabine in cancer.

Although the development of immunotherapies has been revolutionary in the treatment of several cancers, many cancer types remain unresponsive to immune-based treatment and are largely managed by chemotherapy drugs. However, chemotherapeutics are not infallible and are frequently rendered ineffective as resistance develops from prolonged exposure. Recent investigations have indicated that some chemotherapy drugs have additional functions beyond their normative cytotoxic capacity and are in fact immune-modifying agents. Of the pharmaceuticals with identified immune-editing properties, gemcitabine is well-studied and of interest to clinicians and scientists alike. Gemcitabine is a chemotherapy drug approved for the treatment of multiple cancers, including breast, lung, pancreatic, and ovarian. Because of its broad applications, relatively low toxicity profile, and history as a favorable combinatory partner, there is promise in the recharacterization of gemcitabine in the context of the immune system. Such efforts may allow the identification of suitable immunotherapeutic combinations, wherein gemcitabine can be used as a priming agent to improve immunotherapy efficacy in traditionally insensitive cancers. This review looks to highlight documented immunomodulatory abilities of one of the most well-known chemotherapy agents, gemcitabine, relating to its influence on cells and proteins of the immune system.

Abstract 2734: RC148, a novel bispecific antibody targeting PD-1 and VEGF for cancer immunotherapy

Abstract Vascular endothelial growth factor (VEGF) is one of the most important pro-angiogenic factors in modulating tumor microenvironment (TME), and the concentration of VEGF in TME is significantly higher than that of peripheral. Inhibiting VEGF can improve immunotherapy efficacy by modulating the TME, preventing angiogenesis and regulating immune cell populations. Combined anti-VEGF and anti-Programmed cell death protein 1 (PD-1)/Programmed cell death ligand (PD-L1) therapies have exerted potent antitumor effect in preclinic and clinic studies. Therefore, we developed a novel humanized IgG1 silenced bispecific antibody RC148 to target VEGF and PD-1. RC148 allows dimeric VEGF crosslinking and gradually enhances PD-1 binding activity, potentially reduces systemic toxicity of anti-VEGF therapy and enhances antitumor potency via VEGF trigged enrichment in tumor areas. In preclinical studies, RC148 blocks the binding of VEGF to VEGFR and PD-1 to PD-L1, prevents the growth and migration of human umbilical vein endothelial cells, enables efficient T cell activation, exhibited synergistic antitumor effects in rodent models and showed safety profiles in non-human primate studies. Citation Format: Jianmin Fang, Dong Li, Kaiyue Wu, Sisi Wang, Du Li, Guorui Zhao, Shenjun Li, Jing Jiang. RC148, a novel bispecific antibody targeting PD-1 and VEGF for cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2734.

Heating tumors with tumor cell-derived nanoparticles to enhance chemoimmunotherapy for colorectal cancer.

Aim: To investigate the mechanism of doxorubicin (DOX)-induced immunogenic cell death (ICD) and to improve immunotherapy efficacy. Materials & methods: In this study, hybrid vesicles containing DOX (HV-DOX) were prepared by thin-film hydration with extrusion, and the formulated nanoparticles were characterized physically. Furthermore, in vitro experiments and animal models were used to investigate the efficacy and new mechanisms of chemotherapy combined with immunotherapy. Results: DOX improved tumor immunogenicity by alkalinizing lysosomes, inhibiting tumor cell autophagy and inducing ICD. HVs could activate dendritic cell maturation, synergistically enhancing chemotherapeutic immunity. Conclusion: The mechanism of DOX-induced ICD was explored, and antitumor immunity was synergistically activated by HV-DOX to improve chemotherapeutic drug loading and provide relevant antigenic information.

Exploiting Tertiary Lymphoid Structures to Stimulate Antitumor Immunity and Improve Immunotherapy Efficacy.

Tumor-associated tertiary lymphoid structures (TLS) have been associated with favorable clinical outcomes and response to immune checkpoint inhibitors in many cancer types, including non-small cell lung cancer. Although the detailed cellular and molecular mechanisms underlying these clinical associations have not been fully elucidated, growing preclinical and clinical studies are helping to elucidate the mechanisms at the basis of TLS formation, composition, and regulation of immune responses. However, a major challenge remains how to exploit TLS to enhance naïve and treatment-mediated antitumor immune responses. Here, we discuss the current understanding of tumor-associated TLS, preclinical models that can be used to study them, and potential therapeutic interventions to boost TLS formation, with a particular focus on lung cancer research.

Breast Cancer Stem Cells Secrete MIF to Mediate Tumor Metabolic Reprogramming That Drives Immune Evasion.

MIF secreted by breast cancer stem cells induces metabolic reprogramming in bulk tumor cells and engenders an immunosuppressive microenvironment, identifying MIF targeting as a strategy to improve immunotherapy efficacy in breast cancer.

Targeting MEK/COX-2 axis improve immunotherapy efficacy in dMMR colorectal cancer with PIK3CA overexpression.

PIK3CA mutation or overexpression is associated with immunotherapy resistance in multiple cancer types, but is also paradoxically associated with benefit of COX-2 inhibition on patient survival of colorectal cancer (CRC) with mismatch repair deficiency (dMMR). This study examined whether and how PIK3CA status affected COX-2-mediated tumor inflammation and immunotherapy response of dMMR CRC. Murine colon cancer cells MC38, CT26, and CT26-Mlh1-KO were used to construct PIK3CA knockdown and overexpression models to mimic dMMR CRC with PIK3CA dysregulation, and xenograft models were used to evaluate how PIK3CA regulate COX-2 expression, CD8+ T cells infiltration, tumor growth, and therapy response to anti-PD-L1 treatment using immunocompetent mice. Western blot was carried out to delineate the signaling pathways in human and mouse cancer cells, and immunohistochemical analysis together with bioinformatics analysis using human patient samples. PIK3CA upregulates COX-2 expression through MEK/ERK signaling pathway independent of AKT signaling to promote tumor inflammation and immunosuppression. PIK3CA knockdown profoundly reduced CT26 tumor growth in a CD8+ T cell-dependent manner, while PIK3CA overexpression significantly inhibited CD8+ T cells infiltration and promoted tumor growth. Furthermore, MEK or COX-2 inhibition augmented the anti-tumor activity of anti-PD-L1 immunotherapy on dMMR CRC mouse models, accompanied with increased CD8+ T cells infiltration and activated tumor microenvironment. Our results identified that the PIK3CA hyperactivation in dMMR CRC upregulated COX-2 through MEK signaling, which inhibited CD8+ T cells infiltration and promoted tumor growth, together led to immunotherapy resistance. COX-2 or MEK inhibition may relieve therapy resistance and promote therapy efficacy of anti-PD-1/PD-L1 immunotherapy for treating dMMR CRC with PIK3CA overexpression or activating mutation.

Tumorous IRE1α facilitates CD8+T cells-dependent anti-tumor immunity and improves immunotherapy efficacy in melanoma

BackgroundTumor cells frequently suffer from endoplasmic reticulum (ER) stress. Previous studies have extensively elucidated the role of tumorous unfolded protein response in melanoma cells, whereas the effect on tumor immunology and the underlying mechanism remain elusive.MethodsBioinformatics, biochemical assays and pre-clinical mice model were employed to demonstrate the role of tumorous inositol-requiring transmembrane kinase/endoribonuclease 1α (IRE1α) in anti-tumor immunity and the underlying mechanism.ResultsWe firstly found that IRE1α signaling activation was positively associated with the feature of tumor-infiltrating lymphocytes. Then, pharmacological ER stress induction by HA15 exerted prominent anti-tumor effect in immunocompetent mice and was highly dependent on CD8+T cells, paralleled with the reshape of immune cells in tumor microenvironment via tumorous IRE1α-XBP1 signal. Subsequently, tumorous IRE1α facilitated the expression and secretion of multiple chemokines and cytokines via XBP1-NF-κB axis, leading to increased infiltration and anti-tumor capacity of CD8+T cells. Ultimately, pharmacological induction of tumorous ER stress by HA15 brought potentiated therapeutic effect along with anti-PD-1 antibody on melanoma in vivo.ConclusionsTumorous IRE1α facilitates CD8+T cells-dependent anti-tumor immunity and improves immunotherapy efficacy by regulating chemokines and cytokines via XBP1-NF-κB axis. The combination of ER stress inducer and anti-PD-1 antibody could be promising for increasing the efficacy of melanoma immunotherapy.

Abstract B025: IL-1 blockade prevents cardiac toxicity and improves immunotherapy efficacy in mouse models of pancreatic cancer

Abstract Background: Immune checkpoint blockers (ICBs) have revolutionized cancer treatment, but they are often associated with severe immune related adverse events (irAEs). These severe irAEs are more often seen in patients with obesity or concomitantly treated with cytotoxic therapies. Methods: We aimed to understand the mechanisms of ICB-induced irAEs, in the context of obesity and ICB/chemotherapy combinations. We developed a mouse model of cardiac irAEs, which is the most fatal type of irAE in ICB-treated cancer patients, with clinically relevant features: (i) an ICB-resistant cancer (pancreatic ductal adenocarcinoma or PDAC), (ii) obesity induced with high-fat diets, and (iii) a combination treatment of ICB (α-PD1 + α-CTLA4) and chemotherapy (FOLFIRINOX). Results: Our FDA and single institution retrospective analyses indicate that patients treated with ICB had greater relative risk of developing myocarditis as compared to other anti-cancer therapies. Mice with orthotopic PDAC and obesity developed irAEs after treatment with ICB and chemotherapy as compared to chow diet. These irAEs recapitulated those observed in patients with cancer and obesity, including cardiac dysfunction consistent with myocarditis, cardiac fibrosis, and increased circulating levels of interleukin-1 beta (IL-1b). IL-1β blockade prevented myocarditis and reduced cardiac fibrosis after immunotherapy. Importantly, IL-1β blockade also enhanced the anti-tumor effects of ICB + FOLFIRINOX combination therapy, and increased mouse survival. Conclusions: We developed a translationally relevant 'triple hit' mouse model and discovered that IL-1β mediates ICB-induced cardiotoxicity. In addition, we found that IL-1β blockers, which are already used in the clinic for cardiology indications, both reduce adverse events and simultaneously enhance the antitumor effects triggered by immunotherapy. Citation Format: Nilesh P. Talele, Heena Kumra, Igor L. Gomes-Santos, Sylvie Roberge, William W. Ho, Patrick Andersson, Sampurna Chatterjee, Marie Siwicki, Dan G. Duda, Mikael J. Pittet, Dai Fukumura, Rakesh K. Jain. IL-1 blockade prevents cardiac toxicity and improves immunotherapy efficacy in mouse models of pancreatic cancer [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Pancreatic Cancer; 2023 Sep 27-30; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(2 Suppl):Abstract nr B025.

Abstract C017: The anti-fungal itraconazole improves immunotherapy efficacy in pancreatic ductal adenocarcinoma by reversing the immune-suppressive tumor microenvironment

Abstract Pancreatic cancer (PC) has 5-year survival rates of 11% and is projected to become the second leading cause of cancer-related deaths by 2030. Poor outcomes result from early metastasis and a lack of effectual therapies for advanced disease. Our previous large-scale genomics studies revealed PC is molecularly highly varied (1). This heterogeneity, lack of effective therapies and high mortality rate make PC a prime arena to advance personalised medicine strategies, where individual cancers are selected for optimal therapy depending on molecular subtype. Utilising our significant experience of molecular-guided anti-cancer therapies (2-6) and stromal biology expertise (2,6,7), we are taking drug-repurposing approaches to test agents with effects on stromal biology in combination with standard-of-care chemotherapies and immunotherapy, to improve clinical outcomes. Itraconazole is an FDA-approved anti-fungal with potential anti-cancer effects, although its efficacy in PC remains relatively unexplored. Preliminary in vivo findings indicate that itraconazole, in combination with standard-of-care chemotherapy gemcitabine/nab-paclitaxel, significantly delays disease progression in both mouse and patient-derived xenograft models of PC. Single cell RNA-seq analyses of tumors from the KPC orthotopic model of PC suggest itraconazole treatment can inhibit immunosuppressive aspects of the stroma and pro-tumorigenic, pro-metastatic signalling. Excitingly, combining itraconazole with anti-PD1/-CTLA4 immunotherapy provides significant survival advantages in the KPC orthotopic model of PC. Finally, using a model of metastatic PC, we show that itraconazole hinders metastatic colonisation in the liver. This work aims to identify subtypes of PC responsive to itraconazole allowing optimisation and translation of tailored therapies combining itraconazole and the latest clinically-utilised chemotherapies and immunotherapies.

Gut microbiota reshapes cancer immunotherapy efficacy: Mechanisms and therapeutic strategies.

Gut microbiota is essential for maintaining local and systemic immune homeostasis in the presence of bacterial challenges. It has been demonstrated that microbiota play contrasting roles in cancer development as well as anticancer immunity. Cancer immunotherapy, a novel anticancer therapy that relies on the stimulation of host immunity, has suffered from a low responding rate and incidence of severe immune-related adverse events (irAEs). Previous studies have demonstrated that the diversity and composition of gut microbiota were associated with the heterogeneity of therapeutic effects. Therefore, alteration in microbiota taxa can lead to improved clinical outcomes in immunotherapy. In this review, we determine whether microbiota composition or microbiota-derived metabolites are linked to responses to immunotherapy and irAEs. Moreover, we discuss various approaches to improve immunotherapy efficacy or reduce toxicities by modulating microbiota composition.

Helicobacter pylori CagA promotes immune evasion of gastric cancer by upregulating PD-L1 level in exosomes

Cytotoxin-associated gene A (CagA) of Helicobacter pylori (Hp) may promote immune evasion of Hp-infected gastric cancer (GC), but potential mechanisms are still under explored. In this study, the positive rates of CagA and PD-L1 protein in tumor tissues and the high level of exosomal PD-L1 protein in plasma exosomes were significantly associated with the elevated stages of tumor node metastasis (TNM) in Hp-infected GC. Moreover, the positive rate of CagA was positively correlated with the positive rate of PD-L1 in tumor tissues and the level of PD-L1 protein in plasma exosomes, and high level of exosomal PD-L1 might indicate poor prognosis of Hp-infected GC. Mechanically, CagA increased PD-L1 level in exosomes derived from GC cells by inhibiting p53 and miRNA-34a, suppressing proliferation and anticancer effect of CD8+ Tcells. This study provides sights for understanding immune evasion mediated by PD-L1. Targeting CagA and exosomal PD-L1 may improve immunotherapy efficacy of Hp-infected GC.

Polycomb repressor complex 2 suppresses interferon-responsive MHC-II expression in melanoma cells and is associated with anti-PD-1 resistance

BackgroundDespite the remarkable success of immunotherapy in treating melanoma, understanding of the underlying mechanisms of resistance remains limited. Emerging evidence suggests that upregulation of tumor-specific major histocompatibility complex-II (tsMHC-II) serves...

Inhibition of Microsomal Prostaglandin E2 Synthase Reduces Collagen Deposition in Melanoma Tumors and May Improve Immunotherapy Efficacy by Reducing T-cell Exhaustion.

Collagen is a predominant component of the extracellular matrix that may influence the tumor immune microenvironment for cancer progression. We present here that mPGES-1 has specific roles in regulating tumor immunity, associated with several collagen-related genes and propose that pharmacologic inhibition of mPGES-1 may hold therapeutic promise for improving immune checkpoint-based therapies.

Th1 cells inducing IFNγ response improves immunotherapy efficacy in gastric cancer.

Cancer immunotherapy has made remarkable advances in recent years, but its effectiveness in treating gastric cancer is often limited by the complexity of the tumor microenvironment and the lack of effective biomarkers. This study aimed to identify effective biomarkers for immunotherapy treatment by characterizing the tumor microenvironment. We retrieved the RNA-seq data from gastric cancer patients treated with the programmed death 1 (PD-1) blockade pembrolizumab. Differentially expressed genes associated with clinical outcomes were identified and further analyzed using gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Gene signature scores were calculated by single sample Gene Set Enrichment Analysis (ssGSEA). The infiltration levels of immune cells were quantified using the xCell website. Cell type enrichment analysis was performed to compare treatment response and non-response groups, and regression analysis was used to investigate the relationship between interferon gamma (IFNγ) immune response and immune cell infiltration. Biomarkers were identified using least absolute shrinkage and selection operator (LASSO) analysis. Compared to normal tissues, cytokine activity and interleukin-6 production were highly activated in gastric tumors. Responders to pembrolizumab showed significantly up-regulated expression of IFNγ response-related genes. Cell type enrichment analysis revealed that Th1 cells were significantly enriched in the tumor microenvironment of responders. Regression analysis indicated that Th1 cells induced IFNγ response more efficiently than other cell types. Using signatures of Th1 cells, stromal cells and IFNγ response, a set of eight genes were identified that effectively predicted the efficacy of immunotherapy treatment and patient prognosis. Th1 cells promote therapeutic efficacy of PD-1 blockade by promoting IFNγ immune response in gastric cancer. The identified biomarkers have the potential to improve the effectiveness of immunotherapy treatment for gastric cancer patients.

TROP2 expression and response to immune checkpoint inhibition in patients with advanced non-small cell lung cancer.

9040 Background: Despite anti-monoclonal antibodies targeting programmed cell death-1 (PD-1) or its ligand PD-L1 revolution, most patients (pts) with advanced NSCLC displayed primary resistance to PD1/PD-L1 blockade. Identifying targetable alterations involved in resistance represent a promising approach to improve immunotherapy efficacy. TROP2 expression is associated with a poor prognosis in NSCLC, and offers a promising target for treatment with the development of new antibody drug conjugate. TROP2 has been suggested to play a role in innate immunity response, but, it's unclear whether TROP2 expression by tumor cells is detrimental specifically in the context of PD1/PD-L1 blockade. The aim of our study was to investigate the the role of TROP2 expression in outcome of NSCLC pts treated with ICI. Methods: We analyzed the largest NSCLC gene expression data set worldwide including the whole-transcriptome profile of 891 pre-treatment tumors from POPLAR and OAK trials, two randomized studies assessing the efficacy of atezolizumab versus docetaxel in NSCLC. We complemented this transcriptional approach with multiplex IF and digital pathology analysis to confirm our findings at the protein level We investigated whether a non-invasive approach focusing on the level of plasma levels of circulating TROP2 may be relevant to predict efficacy of ICI. Results: The PFS of pts with high expression of TROP2 was significantly lower than in pts with low expression 2.5 vs 4.1 months, p < 0.001. Strikingly, high TROP2 expression was also associated with lower clinical benefit rate 15% vs 28%, p = 0.009 and worse overall survival (OS) 12.6 vs 16.3 months, p = 0.007 When adjusting for covariates such as histological subtype, TLS signature, PD-L1 expression, TROP2 remained independently associated with PFS and OS. None of these correlations were observed in the docetaxel arm, suggesting a predictive value of TROP2 gene expression specifically for response to ICI. By using a deconvolution approach, we also observed that TROP2-high tumors were characterized by a significant lowest expression of genes specific to immune populations (T effector memory cells,Th17 cells). Multiplex IF on an independent cohort 53 NSCLC tumors confirmed the correlation between high TROP2, microenvironment features and poor response to PD1 inhibition. Analysis of circulating plasma levels of TROP2 in 97 NSCLC patients revealed a strong correlation with expression in tumor tissue. High plasma levels of circulating TROP2 was also significantly associated with worse ORR, PFS and OS on treatment with PD1/PDL1 antagonist. Conclusions: Our study revealed that TROP2 expression by tumor cells in NSCLC is associated with worse outcome in patients with NSCLC independently of PDL1 expression. Targeting TROP2 in combination with ICI may represent a promising strategy to improve ICI efficacy in pts with TROP2-high NSCLC.

GADD45B predicts lung squamous cell carcinoma survival and impacts immune infiltration, and T cell exhaustion

Background: This study focussed on exploring the prognostic prediction performance of the growth arrest and DNA damage-inducible 45 beta (GADD45B) and its associations with T-cell activity and immune soakage in different malignancies, especially lung squamous cell carcinoma (LUSC). Methods: We applied TIMER database for comparing the expressions of GADD45B among different cancers. OncoLnc, Gene Expression Profiling Interactive Analysis 2 (GEPIA2), and Kaplan-Meier Plotter were utilised to evaluate the prognostic prediction performance of GADD45B. Besides, the associations of GADD45B with clinical stage, associated gene markers, and immune infiltration were examined through TISIDB, GEPIA2, and Tumour Immune Estimation Resource (TIMER). Biological processes (BPs) and KEGG enrichment analyses were performed to illustrate the possible role of GADD45B in LUSC. The miRWalk database was adopted to analyse the gene miRNA interaction network of GADD45B in LUSC. Results: GADD45B expression was decreased in most of the malignancies, with relation to the poor prognosis in LUSC. GADD45B also significantly affected the survival of LUSC subgroups divided by clinic data. GADD45B significantly correlates with and may stimulate T cell exhaustion in LUSC. Conclusions: GADD45B is a prognostic indicator in multiple tumours, especially in LUSC. Moreover, modulating GADD45B expression may improve immunotherapy efficacy in LUSC.

Targeting Gut Microbiota in Cancer Therapy

Our knowledge of the complex interactions between the gut microbiome and the numerous mechanisms by which they affect health and illness has greatly increased. Recent evidence suggests the composition of the gut microbiota can alter the effectiveness of both cancer radiation and immunotherapies. However, existing microbiota-based modification techniques including fecal microbiota transplantation, antibiotics, prebiotics, probiotics, and postbiotics are insufficient due to the wide variety and fluidity of the microbiota. With the advancement of next-generation sequencing and CRISPR techniques, future research will be able to accurately identify favorable and non-favorable microbial targets that can improve immunotherapy efficacy and expand the use of microbiota precision medicine.