Chemo-Radio-Immunotherapy Strategies to Prevent Immune Resistance in Non-Small Cell Lung Cancer.

Response to immune checkpoint blockade (ICB) in non-small cell lung cancers (NSCLC) is associated with recurring mutations in tumor suppressor genes STK11 and TP53. Whereas STK11-mutated patients are mostly insensitive, TP53-mutated patients commonly respond to ICB. Previous studies have linked mutational status in these genes to differences in cell type composition of the tumor microenvironment (TME). However, it remains unclear if differences in cell type compositions as well as cell-cell interactions in turn could account for the observed differences in treatment response and overall survival in NSCLC. Here, we perform spatial profiling of immune and stromal phenotypes in the TME of 119 NSCLC patients using imaging mass cytometry (IMC) on tissue microarrays (TMA). Matching data from MSK IMPACT (clinical sequencing) was used to establish mutation profiles and therapeutic response was included in the analysis. We find that STK11-mutated NSCLC is characterized by decreased CD4 T cell and increased neutrophil abundance, while TP53-mutated NSCLC is associated with increased CD8 T cell and decreased endothelial cell abundance. Accordingly, we stratified the patient population into TME classes by cell type composition. We found that while mutational status does not inform overall survival in our cohort, stratification by cell type abundance strongly associates with patient outcome (p-value: 0.000146, logRank test). Patients with neutrophil-rich TMEs show worse overall survival (25% 5-year survival), while patients with increased endothelial cell and macrophage abundance have a tendency to live longer (80% and 75% 5-year survival respectively). Furthermore, we interrogate pairwise proximity of immune cell types and states to construct cellular networks in NSCLC. Together, our findings suggest that TME cell type composition and cellular networks are potential molecular determinants for ICB therapeutic response in NSCLC patients. Citation Format: Florian Uhlitz, Douglas Linn, Elsa Beyer Krall, Jacklynn Egger, Hira Rizvi, Jason Chang, Benjamin Nicholson, Rami Vanguri, Andrew Chow, Matthew Hellmann, Sohrab Shah. Spatial immune determinants of ICB response in STK11-mutated 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 LB049.

A major hurdle in treatment of Non-Small Cell Lung Cancer (NSCLC) with anti-PD-1 immune checkpoint blockade (ICB) therapy is a lack of response (primary resistance) and relapse after an initial response (acquired resistance). Recent studies reveal that responses to PD-1/PD-L1 blockade are associated with high tumor mutational burden (TMB), increased CD8+ T cell infiltration and high baseline PD-L1 expression within the tumor microenvironment (TME), while impaired tumor antigen presentation and the immunosuppressive TME have been associated with resistance to ICB. One approach to overcome anti-PD-1 resistance is to intratumorally vaccinate NSCLC tumors with gene modified conventional dendritic cells (cDC), specifically the type I conventional DC (cDC1) lineage. Recent studies have established that generation of an anti-tumor immune response driven by CD8+ T cells requires the cross presentation of tumor associated antigens and that cDC1s are the primary cross presenting APC subtype in vivo, which can license CD8+ T cells to initiate an adaptive anti-tumor immune response. In addition, previous studies have shown that intratumoral administration of the FMS-like tyrosine kinase 3 ligand (FLT3L) protein can expand endogenous CD103+ cDC1 cells in the TME and augment anti-tumor immune responses to ICB therapy. Here, we engineered murine CD103+ cDC1 cells to constitutively secrete soluble FLT3L (FLT3L_cDC1) and performed in situ vaccination studies on anti-PD1 resistant murine models of NSCLC with LKB1-deficiency and elevated TMB that better represents human disease. The FLT3L_cDC1 cells showed enhanced anti-tumor efficacy compared to non-modified cDC1 cells and synergized with anti-PD-1 ICB to inhibit tumor growth. Our data suggests intratumoral injection of FLT3L_cDC1 cells may represent a promising strategy to potentiate the efficacy of ICB and improve outcomes for patients with primary resistance PD-1/PD-L1 monotherapy. *B. Liu and S.M Dubinett contributed equally to this work Citation Format: Jensen W. Abascal, Raymond J. Lim, Ramin Salehi-Rad, Zhe Jing, William P. Crosson, Bitta P. Kahangi, Edgar Perez Reyes, Diana Reyimjan, Jessie Zhu, Linh M. Tran, Manash Paul, Kostyantyn Krysan, Bin Liu, Steven M. Dubinett. In situvaccination with Flt3l gene-modified CD103+type 1 conventional dendritic cells (cDC1) in murine models of non-small cell lung cancer (NSCLC) [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 4212.

A major hurdle in treatment of Non-small cell lung cancer (NSCLC) with anti-PD-1 immune checkpoint blockade (ICB) therapy is a lack of response (primary resistance) and relapse after an initial response (acquired resistance). Recent studies reveal that responses to PD-1/PD-L1 blockade are associated with high tumor mutational burden (TMB), increased CD8+ T cell infiltration, and high baseline PD-L1 expression within the tumor microenvironment (TME), while impaired tumor antigen presentation and the immunosuppressive TME have been associated with ICB resistance. Numerous studies have established that the generation of an anti-tumor immune response driven by CD8+ T cells requires type I conventional dendritic cell (cDC1) mediated cross presentation of tumor associated antigens, which can license CD8+ T cells to initiate an anti-tumor immune response. In addition, previous publications have shown that systemic administration of the FMS-like tyrosine kinase 3 ligand (FLT3L) cytokine can expand endogenous cDC1s in the TME and augment anti-tumor immune responses to ICB therapy. Considering these data, we hypothesize that a viable approach to overcome NSCLC anti-PD-1 resistance is to intratumorally vaccinate tumors with Flt3l-gene modified cDC1s. Using lenti-viral transduction, we engineered murine CD103+ cDC1s to constitutively secrete FLT3L (FLT3L_cDC1) and performed in situ vaccination studies on murine models of NSCLC with Lkb1-deficiency and elevated TMB that better represents human disease. In situ vaccination with FLT3L_cDC1 promotes anti-tumor immune responses in NSCLC tumors that are non-responders to unmodified cDC1 vaccination and synergizes with anti-PD-1 ICB to significantly inhibit tumor growth. FLT3L_cDC1 therapy induces significant activation and expansion T cells within the TME at both an early and late timepoint post vaccination. Furthermore, FLT3L_cDC1 + anti-PD-1 combination therapy significantly increases DC progenitor numbers within the tumor draining lymph node, including DC progenitors that are committed to the cDC1 lineage. NSCLC tumor bearing mice cured following FLT3L_cDC1 + anti-PD-1 therapy independently reject rechallenge with the same NSCLC tumor model, suggesting that combination therapy promotes tumor-specific immune memory responses. Our data suggests in situ vaccination with FLT3L_cDC1 represents a promising strategy to potentiate the efficacy of ICB and can improve outcomes for patients with primary resistance to PD-1/PD-L1 monotherapy. Citation Format: Jensen Abascal, Ramin Salhi-Rad, Michael S Oh, William P Crosson, Camelia Dumitras, Bin Liu, Steven M Dubinett. In situ vaccination with Flt3l gene-modified CD103+ type 1 conventional dendritic cells (cDC1) in murine models of non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the AACR IO Conference: Discovery and Innovation in Cancer Immunology: Revolutionizing Treatment through Immunotherapy; 2025 Feb 23-26; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Immunol Res 2025;13(2 Suppl):Abstract nr A033.

PurposeThe DNA methylation inhibitor 5-aza-2′-deoxycytidine (DAC) is approved for the treatment of myelodysplastic syndromes (MDS), but resistance to DAC develops during treatment and mechanisms of resistance remain unknown. Therefore, we investigated mechanisms of primary and secondary resistance to DAC in MDS.Patients and MethodsWe performed Quantitative Real-Time PCR to examine expression of genes related to DAC metabolism prior to therapy in 32 responders and non-responders with MDS as well as 14 patients who achieved a complete remission and subsequently relapsed while on therapy (secondary resistance). We then performed quantitative methylation analyses by bisulfite pyrosequencing of 10 genes as well as Methylated CpG Island Amplification Microarray (MCAM) analysis of global methylation in secondary resistance.ResultsMost genes showed no differences by response, but the CDA/DCK ratio was 3 fold higher in non-responders than responders (P<.05), suggesting that this could be a mechanism of primary resistance. There were no significant differences at relapse in DAC metabolism genes, and no DCK mutations were detected. Global methylation measured by the LINE1 assay was lower at relapse than at diagnosis (P<.05). On average, the methylation of 10 genes was lower at relapse (16.1%) compared to diagnosis (18.1%) (P<.05).MCAM analysis showed decreased methylation of an average of 4.5% (range 0.6%–9.7%) of the genes at relapse. By contrast, new cytogenetic changes were found in 20% of patients.ConclusionPharmacological mechanisms are involved in primary resistance to DAC, whereas hypomethylation does not prevent a relapse for patients with DAC treatment.

Simple SummaryNSCLC accounts for approximately 84% of lung malignancies and the clinical application of ICIs provides a novel and promising strategy. However, approximately 80% of NSCLC patients do not benefit from ICIs due to drug resistance complicated by disciplines and diverse mechanisms. Through this review, we provide a whole map of current understanding of primary and acquired resistance mechanisms in NSCLC. In the first part, resistance mechanisms of 6 FDA-approved ICIs-related primary resistance are collected and arranged into 7 steps of the well-known cancer-immunity cycle. Acquired resistance induced by ICIs are summarized in the second part. In the third part, we discuss the future direction, including the deeper understanding of tumor microenvironment and the combinational treatment. Through this review, clinicians can get clear and direct clues to find the underlying mechanisms in patients and translational researchers can acquire several directions to overcome resistance and apply new combinational treatment.Immune checkpoint inhibitors have emerged as the treatment landscape of advanced non-small cell lung cancer (NSCLC) in recent years. However, approximately 80% of NSCLC patients do not benefit from ICIs due to primary resistance (no initial response) or acquired resistance (tumor relapse after an initial response). In this review, we highlight the mechanisms of primary and secondary resistance. Furthermore, we provide a future direction of the potential predictive biomarkers and the tumor microenvironmental landscape and suggest treatment strategies to overcome these mechanisms.

Background: Although immune checkpoint blockade (ICB) targeting Programmed Death-1/Programmed Death-Ligand 1 (PD-1/PD-L1) alone or in combination with chemotherapy is now a first-line option for patients with advanced NSCLC, the majority of patients do not benefit from anti-PD-1/PD-L1 monotherapy, and the combination with chemotherapy is often associated with toxicity. For patients who initially respond to PD-1/PD-L1 inhibition, many relapse after an initial response and are in need for innovative strategies to overcome the resistance to ICB. One possible approach is to utilize in situ vaccination with functional chemokine gene-modified antigen presenting cells (APCs) that take advantage of the full repertoire of tumor antigens in the tumor microenvironment (TME) in order to restore tumor antigen presentation, promote tumor infiltration of immune cells driven by chemokine gradient, and facilitate tumor-specific T cell activation, both locally and systemically. The chemokine CCL21 is a therapeutic candidate due to its ability to promote infiltration and co-localization of naïve T cells and antigen-experienced dendritic cells (DCs) and facilitate T cell activation. In preclinical studies as well as a phase I clinical trial, we observed that intratumoral (IT) injection of CCL21-DC induces the infiltration of autologous DC and T cells into the TME, and generates systemic tumor-specific immune responses against multiple tumor antigens. We also observed tumoral PD-L1 upregulation following CCL21-DC injection, which may hinder T cell function. Similarly, the lack of efficacy of PD-1/PD-L1 inhibitors could potentially be combated by enhanced T cell infiltration and augmented APC function in the TME following in situ vaccination with CCL21-DC. Therefore, we are currently evaluating the safety and efficacy of combining IT CCL21-DC and intravenous (IV) pembrolizumab in advanced NSCLC patients following progression on ICB or tyrosine kinase inhibitor (TKI) therapy in a phase I trial (NCT03546361). Methods: Phase I, dose-escalating, multi-cohort trial followed by dose expansion. Maximum of 24 patients (9-12 escalation + 12 expansion) with stage IV NSCLC will be evaluated who have tumors accessible for IT injection and are either EGFR/ALK wild-type after progression on a PD-(L)1 inhibitor or EGFR/ALK mutant after progression on TKI. Three IT injections of autologous CCL21-DC (days 0, 21, 42) will be concurrently administered with pembrolizumab, followed by q3wk pembrolizumab up to 1 year. Primary objective of dose escalation is safety and determination of maximum tolerated dose (MTD) of IT CCL21-DC when combined with pembrolizumab. Primary objective of dose expansion is objective response rate at MTD. Secondary objectives include adverse event profiling and immune monitoring studies. [B.L. and A.L. contributed equally to this work as first authors.] Citation Format: Bin Liu, Aaron Lisberg, Ramin Salehi-Rad, Jay Lee, Linh M. Tran, Kostyantyn Krysan, Raymond Lim, Camelia Dumitras, Zhe Jing, Michael Oh, Fereidoun Abtin, Robert Suh, Scott Genshaft, Scott Oh, Gregory Fishbein, Ciara M. O'Higgins, Anita Kaul, Kanwarpal Kahlon, Shahryar Ashouri, Jonathan Goldman, David Elashoff, Edward Garon, Steven Dubinett. Phase I trial of in situ vaccination with autologous CCL21 gene-modified dendritic cells (CCL21-DC) combined with pembrolizumab for advanced non-small cell lung cancer (NSCLC) [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 CT219.

Merkel cell carcinoma (MCC) is a rare and aggressive skin cancer, which is associated in 80% of cases with the Merkel cell polyomavirus (MCPyV). Advanced stages respond to immune checkpoint inhibitors in 50% of cases. Major issues remain unanswered regarding its oncogenesis and optimal treatment. MCPyV-negative and MCPyV-positive MCCs have been hypothesized to derive from distinct cells, although the cell of origin remains a matter of debate. The crucial role the MCPyV small T oncoprotein was recently confirmed by its ability to inactivate p53, together with its contribution to the metastatic progression. In advanced cases, tumoral microenvironment may adequately predict responses to immunotherapies, and several mechanisms of primary and secondary resistance have been investigated. Identifying the mechanisms of oncogenesis allow experimentation of new therapeutic targets, which remain mandatory even at the era of immunotherapies. Although new insights in the mechanisms of primary and secondary resistance pave the way for development of further immunotherapy strategies, neoadjuvant strategies may challenge our whole approach of the disease.

Cytoreduction and the Optimization Of Immune Checkpoint Inhibition with Radiation Therapy

Background: Immunotherapy is firmly established as a treatment regimen in various solid tumors due to its exceptional benefits observed in a select group of patients. Despite widespread use of immune checkpoint blockade (ICB) across diverse solid tumors, including non-small cell lung cancer (NSCLC), the quest for a clinically informative biomarker for long-term benefit remains unmet. Here we investigate the potential utility of clinicopathological and spatial proteomic profiling of tumor specimens from NSCLC patients to identify predictive biomarkers of long-term benefit to ICB. Methods: Forty-nine patients diagnosed with advanced NSCLC who received ICB at Hospital del Mar, Barcelona between 2017-2021 were included. Long-term responders (LTR, n=21) were defined as patients achieving a maintained radiologic response for more than 2 years, and short-term responders (STR, n=28) as patients presenting disease progression within the first six months of ICB initiation. Clinicopathological information, incidence of immune related adverse (irAES) and PD-L1 tumor proportion score assessed by IHC was available for all of them. DSP GeoMx was performed in subset of patients (LTR n=14 and STR n=14), to assess 49 immune biomarkers. Pancytokeratin (panCK; epithelial), CD3, CD20 and SYTO 13 (nuclear) were utilized as morphology biomarkers. Regions of interest were placed in tissue areas containing tumor and segmented in Tumor (PanCK+) and tumor microenvironment (TME) (PanCK-) that was used on downstream analysis. Digital counts were normalized using the protein expression of housekeeper proteins. Statistical analysis was performed using linear mixed models. A P value less than 0.05 was considered significant. Results: Our analysis revealed specific characteristics of LTR patients compared with STR, namely LTR population was enriched for PD-L1 positive in tumors (p=0.005) and a higher incidence of immune-related adverse events (irAEs) (p=0.001). Within the Tumor compartment, LTR patients displayed significantly higher levels of IDO1, CD8, PD-L1, CD45, HLA-DR and STING, while STR patients exhibit higher levels of B7-H3, CD56 and OX40L (p&amp;lt;0.05 for all proteins). Comparison analysis of the TME compartment between LTR and STR revealed augmented levels of IDO1, CD8, CD45, CD11c, CD27 and CD3 in LTR patients, and lower levels of B7H3 and OX40L compared with STR patients (p&amp;lt;0.05 for all proteins). Conclusions: Our comprehensive analysis of metastatic NSCLC patients treated with ICB has unveiled distinct clinicopathological and immunological features associated with long-term benefit of ICB, highlighting the presence of pre-existing antitumor immunity as a stronger predictor of long-term benefit. These findings offer insights into potential biomarkers and therapeutic strategies for enhancing ICB outcomes in metastatic NSCLC. Citation Format: Sharia Hernandez, Rafael Bach, Mario Giner, Wei Lu, Larisa Kostousov, Sean Barnes, Khaja Khan, Laura Masfarré, Xavier Villanueva, Ignacio Sanchéz, Nil Navarro, Álvaro Taus, Miguel Galindo, Max Hardy, Raúl Del Rey-Vergara, Albert Iñañez, Beatriz Sanchez-Espiridion, Laura Moliner, Sergi Clavé, Beatriz Bellosillo, Ana Rovira, Júlia Perera-Bel, Ignacio Wistuba, Edurne Arriola, Luisa M. Solis, Pedro Rocha. Spatial proteomic profiling unveils pre-existing anti-tumor immunity as a hallmark of exceptional benefit from immunotherapy in NSCLC [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 6391.

BackgroundNon-coding RNAs (ncRNAs), including small nucleolar RNAs (snoRNAs), are widely involved in the physiological and pathological processes of human beings. While up to date, although considerable progress has been achieved...

Audit of Molecular Mechanisms of Primary and Secondary Resistance to Various Generations of Tyrosine Kinase Inhibitors in Known Epidermal Growth Factor Receptor-Mutant Non-small Cell Lung Cancer Patients in a Tertiary Centre

Although Anti PD(L)1 therapy lead to impressive therapeutic responses by reinvigorating T cells, primary and secondary resistances occur de novo or during treatment impeding the full efficacy of the drug. To tackle this resistance mechanisms and reduced the immunotoxicity of combination therapy, we designed a 2nd generation of anti-PD1 antibody by fusing immune protein to the Fc portion of the antibody, named BiCKI®. The anti PD1 will more selectively drive the immune active drug on antigen-experienced (PD1+) T cells, through cis-targeting mechanism. These bifunctional molecules were designed with an optimized anti-PD1 backbone for bispecific format, fused to an active protein domain to the C-ter of heavy and/or light chains. Different protein candidate were successfully fused to the optimized anti-PD1, such as cytokines, costimulatory molecules, or dominant negative receptors with PD1/PDL1 full antagonistic activity. In contrast to combination, BiCKI® antibodies enable the simultaneous dual-binding specificity in a single drug allowing a synergistic activation. Each BiCKI® is selected on its synergistic capacity to re-activate of anti-tumor T cell responses or TCR signaling in cell-based assays. Bispecific antibody development in clinic has been hampered by difficult manufacturing process, reduced pharmacokinetic (PK) and drug exposure. Both anti PD-1 CDRs and VH/VL framework sequences were carefully selected and optimized for bioproductivity and biostability of the molecule. A 2 to 15-fold increased productivity in mammalian cells was observed versus the non-optimized anti-PD1 antibody or other anti-PD-1 bispecific backbones as Pembrolizumab or Nivolumab. We also evaluated the impact of the Fc isotype,linker flexibility and affinity of the fused compound on the PK profile of different bispecifics fused to costimulatory molecules or cytokines. The IgG isotype with reduced FcgR binding property, of the anti-PD-1 backbone was associated with a better PK profile with some exceptions for cytokine. The presence or length of a linker between Fc domain and the fused protein has a small impact the PK and drug efficacy. More importantly, the affinity of the fused compound has an impact the PK profile of BiCKI® For example, the anti-PD-1 fused to wild-type IL-7 cytokine possesses a high affinity for the CD127/CD132 receptors but display a reduced drug exposure both in mouse and cynomolgus. This potential difficulty was solved with further improved products including IL-7 mutants having reduced affinity for CD127 and/or CD132. While significant correlation between IL7 affinity and PK has been observed, increased PK and drug exposure could be achieved using optimized combination of Fc isotype a linker length design and BiCKI-IL7 mutants retaining significant IL7R signaling. Conclusion: Our BICKI® platform was designed to overcome major hurdles of bispecific antibody development, we improved its manufacturability and drug exposure by selectively designing the structure of bispecific antibodies. By fusing costimulatory molecule, cytokines or dominant negative receptor to the anti PD-1 blocking antibody, we can generate and select various efficient bispecific molecules acting in synergy to counteract primary and secondary resistance mechanisms of anti-PD(L)1 therapies. Citation Format: Caroline Mary, Aurore Morello, Virginie Thepenier, Géraldine Teppaz, Justine Durand, Nicolas Poirier. Bispecific anti-PD1 checkpoint inhibitors antibodies (BiCKI), an optimized platform designed to tackle anti-PD-(L)1 primary and secondary resistance mechanisms [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 2287.

Mutations in MET that induce skipping of exon 14 and lead to reduced ubiquitin ligase-mediated turnover of this receptor tyrosine kinase (RTK) are detected in 3-4% of non-small cell lung cancer (NSCLC), approaching the prevalence of ALK-rearranged lung cancers. Preclinical and clinical studies have revealed that MET exon14 alterations are actionable oncogenic drivers that are amenable to therapy with MET kinase inhibitors such as crizotinib. However, similar to most kinase-driven cancers, despite initial benefit, acquired resistance to therapy is inevitable. Next-generation sequencing (MSK-IMPACT 468 gene panel) was performed on samples from 81 NSCLC patients with MET exon14 alterations, including 7 with paired pre- and post-treatment tumor samples. A concurrent KRAS G12 mutation was identified in 5 patients. In 4 of these patients, the KRAS mutation was present prior to receiving crizotinib. The KRAS mutation was acquired post-crizotinib in the remaining patient. These findings implicate KRAS activation as a potential mechanism of acquired resistance. Using isogenic and patient-derived in vitro and in vivo models harboring MET exon14 skipping alteration, we confirmed that the KRAS mutation results in constitutive activation of RAS/ERK signaling and cells expressing both MET exon14 skipping and KRAS mutations are refractory to MET inhibition. Dual inhibition of MET and MEK with crizotinib and trametinib, respectively, has an additive effect in cell line and xenograft models. Whereas concurrent KRAS mutation is an extremely rare event in EGFR- and ALK-driven NSCLC, our findings confirm KRAS mutation as a recurrent mechanism of primary or secondary resistance to MET-directed therapies in lung cancers harboring MET exon14 alterations. We provide a new potential therapeutic strategy for NSCLC patients with both MET exon14 alterations and KRAS mutations. Citation Format: Ken Suzawa, Michael D. Offin, Christopher Kurzatkowski, Daniel Liu, Morana Vojnic, Roger S. Smith, Marissa Mattar, Inna Khodos, Elisa de Stanchina, Joshua K. Sabari, William W. Lockwood, Alexander E. Drilon, Marc Ladanyi, Romel Somwar. Oncogenic KRAS mediates resistance to MET targeted therapy in non-small cell lung cancer (NSCLC) with MET mutations that induce exon14 skipping [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1826.

Immune checkpoint blockade (ICB) therapy has achieved breakthroughs in the treatment of advanced non-small cell lung cancer (NSCLC). Nevertheless, the low response due to immuno-cold (i.e., tumors with limited tumor-infiltrating lymphocytes) tumor microenvironment (TME) largely limits the application of ICB therapy. Based on the glycolytic/cholesterol synthesis axis, a stratification framework for EGFR-WT NSCLC was developed to summarize the metabolic features of immuno-cold and immuno-hot tumors. The cholesterol subgroup displays the worst prognosis in immuno-cold NSCLC, with significant enrichment of the cholesterol gene signature, indicating that targeting cholesterol synthesis is essential for the therapy for immuno-cold NSCLC. Statin, the inhibitor for cholesterol synthesis, can suppress the aggressiveness of NSCLC in vitro and in vivo and can also drastically reverse the phenotype of immuno-cold to an inflamed phenotype in vivo. This change led to a higher response to ICB therapy. Moreover, both our in-house data and meta-analysis further support that statin can significantly enhance ICB efficacy. In terms of preliminary mechanisms, statin could transcriptionally inhibit PD-L1 expression and induce ferroptosis in NSCLC cells. Overall, we reveal the significance of cholesterol synthesis in NSCLC and demonstrate the improved therapeutic efficacy of ICB in combination with statin. These findings could provide a clinical insight to treat NSCLC patients with immuno-cold tumors.

e14618 Background: Immune checkpoint blockade (ICB) has achieved remarkable success. However, not all patients with advanced tumors respond to ICB. Remodeling of the tumor microenvironment (TME) has emerged as a strategy to facilitate the development of cancer therapies. As the most notable features of TME, immune cells and collagens play a significant role in influencing anti-tumor immunity, with collagen deposition is the most significant physical barrier that hinders immune cell infiltration. Cancer patients are often prescribed multiple medications to address pre-existing comorbidities or side effects from anti-tumor therapy. Given the high prevalence of concurrent medications and the potential for interactions between them and ICB, we identified that the angiotensin II receptor 1 (AGTR1) was positively expressed in CAFs and AGTR1 inhibitor angiotensin receptor blocker (ARB) suppressed the expression of type I collagen and promote immune infiltration. Methods: Retrospective clinical study: An in-house cohort was a multi-center cohort and included 270 patients with non-small-cell lung cancer (NSCLC) receiving ICB therapy from 2020 to 2021 from The Affiliated Wuxi People's Hospital of Nanjing Medical University and The First Affiliated Hospital of Nanjing Medical University. Meta-analysis: 4 studies involving 1,268 participants in total and an in-house cohort with 270 participants were included. We performed an additional meta-analysis on the association between the use of ARBs in cancer patients receiving ICB therapy. Animal models: Xenograft tumor models were randomly divided into two groups, including control and Losartan-treated groups, and mouse cancer models were randomly divided into three groups at the first round and four groups at the second round. Three groups included control, Losartan-treated, and Losartan-treated &amp; CD8-deleted groups, and four groups included control, Losartan-treated, anti-PD-1-treated, and Losartan &amp; anti-PD-1-treated groups. Results: Patients with NSCLC who received ARBs showed improved overall survival and response to immunotherapy compared to those who did not receive ARBs. Losartan, a representative drug of the ARB class, significantly increased collagen deposition in mice tumors, elevated levels of immune cell infiltration, and sensitized anti-PD-1 therapy. Conclusions: We reported that Losartan shaped an inflamed TME by inhibiting collagen I expression of CAFs and enhanced anti-PD-1 immunotherapy in the mouse tumor model. We recommend that ARB should be selected as much as possible for patients receiving ICB therapy and requiring antihypertensive treatment.