Immune Checkpoint Blockers Research Articles

Co-delivery of PDL1-blocking scFv and chemotherapeutics using engineered exosomes for cancer therapy

Poor clinical outcomes after immune checkpoint blockers alone may be offset by the combination of chemotherapeutic agents. However, safe, effective and simultaneous delivery of immune checkpoint blockers and chemotherapeutics to tumor cells poses a great challenge. In this study, we took advantage of the low biotoxicity, cargo shielding and immune privilege of exosomes to construct an engineered exosome that can co-deliver chemotherapeutic paclitaxel (PTX) and PDL1-blocking single-chain variable fragments (scFv) specifically to the cancer cells. We demonstrated that the PDL1-blocking scFv expressed on the surface of the exosomes well bound to PD-L1 and significantly reduced the inhibitory effect of PD-L1 on T cells. Moreover, engineered exosomes loaded PTX were more effectively absorbed by the recipient cells as compared to free PTX or control exosomes loaded PTX. In addition, the intravenous injection of APLG-EXO-PTX also inhibited the tumor growth in colon carcinoma xenograft model mice, and showed a significantly increased expression of effector cytokine, IFN-γ indicating that the engineered exosome loaded with PTX could significantly upregulate T-cell activation. The strategy of co-delivering functional scFv and anti-cancer drugs via exosomes heralds a potential approach to improve the effectiveness of cancer treatment in the near future.

Immune Checkpoint Inhibitor-Based Combination Therapy for Colorectal Cancer: An Overview.

Colorectal cancer (CRC) is one of the most common diseases in the world. Tumor immunotherapy is an innovative cancer treatment that acts by activating the human body's autoimmune system. Immune checkpoint block has been shown to be effective in DNA deficient mismatch repair/microsatellite instability-high CRC. However, the therapeutic effect for proficient mismatch repair/microsatellite stability patients still requires further study and optimization. At present, the main CRC strategy is to combine other therapeutic methods, such as chemotherapy, targeted therapy, and radiotherapy. Here, we review the current status and the latest progress of immune checkpoint inhibitors in the treatment of CRC. At the same time, we consider therapeutic opportunities for transforming cold to hot, as well as perspectives on possible future therapies, which may be in great demand for drug-resistant patients.

Cutaneous Adverse Reactions of Immunotherapy in Patients with Advanced Melanoma.

Immune checkpoint blockers (ICBs) have been widely used during the last decade for the treatment of various tumors, including advanced and metastatic melanoma. While these agents have improved melanoma patients' survival rates, they have also been associated with various autoimmune toxicities, with the skin being most commonly affected. The severity of cutaneous toxicity can not only negatively affect patients' quality of life but can also limit the proper treatment of cancer. Thus, the role of the dermatologist is substantial in early detecting and promptly treating these adverse events. Maculopapular rash, psoriasiform, lichenoid dermatoses and bullous pemphigoid are the most frequent cutaneous adverse events that require immediate intervention. Other rare autoimmune toxicities, e.g., sarcoidosis, dermatomyositis or subacute lupus, have also been reported. In this review, we summarize the aspects of ICB-induced cutaneous toxicities in patients with melanoma, emphasizing their management and treatment options in clinical practice.

A maladaptive pleural environment suppresses preexisting anti-tumor activity of pleural infiltrating T cells.

Treatment options for patients with malignant pleural effusions (MPE) are limited due, at least in part, to the unique environment of the pleural space, which drives an aggressive tumor state and governs the behavior of infiltrating immune cells. Modulation of the pleural environment may be a necessary step toward the development of effective treatments. We examine immune checkpoint molecule (ICM) expression on pleural T cells, the secretomes of pleural fluid, pleural infiltrating T cells (PIT), and ability to activate PIT ex vivo. ICM expression was determined on freshly drained and in vitro activated PIT from breast, lung and renal cell cancer. Secretomics (63 analytes) of activated PIT, primary tumor cultures and MPE fluid was determined using Luminex technology. Complementary digital spatial proteomic profiling (42 analytes) of CD45+ MPE cells was done using the Nanostring GeoMx platform. Cytolytic activity was measured against autologous tumor targets. ICM expression was low on freshy isolated PIT; regulatory T cells (T-reg) were not detectable by GeoMx. In vitro activated PIT coexpressed PD-1, LAG-3 and TIGIT but were highly cytotoxic against autologous tumor and uniquely secreted cytokines and chemokines in the > 100 pM range. These included CCL4, CCL3, granzyme B, IL-13, TNFα, IL-2 IFNγ, GM-CSF, and perforin. Activated PIT also secreted high levels of IL-6, IL-8 and sIL-6Rα, which contribute to polarization of the pleural environment toward wound healing and the epithelial to mesenchymal transition. Addition of IL-6Rα antagonist to cultures reversed tumor EMT but did not alter PIT activation, cytokine secretion or cytotoxicity. Despite the negative environment, immune effector cells are plentiful, persist in MPE in a quiescent state, and are easily activated and expanded in culture. Low expression of ICM on native PIT may explain reported lack of responsiveness to immune checkpoint blockade. The potent cytotoxic activity of activated PIT and a proof-of-concept clinical scale GMP-expansion experiment support their promise as a cellular therapeutic. We expect that a successful approach will require combining cellular therapy with pleural conditioning using immune checkpoint blockers together with inhibitors of upstream master cytokines such as the IL-6/IL-6R axis.

Exploration and analysis of differentially expressed genes in Epstein-Barr virus negative and positive plasmablastic lymphoma.

Plasmablastic lymphoma (PBL) is a subtype of diffuse large B-cell lymphoma (DLBCL) often associated with Epstein-Barr virus (EBV) infection. Despite recent advances in treatment, PBL still has a poor prognosis. EBV is listed as one of the human tumor viruses that may cause cancer, and is closely related to the occurrence of some nasopharyngeal carcinoma (NPC), lymphoma and 10% of gastric cancer (GC). It is very important to explore the differentially expressed genes (DEGs) between EBV-positive and EBV-negative PBL. Through bioinformatics analysis of DEGs between EBV-positive PBL and EBV-negative PBL, we gain a deeper understanding of the pathogenesis of EBV-positive PBL. We selected the GSE102203 data set, and screened the DEGs between EBV-positive PBL and EBV-negative PBL. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were applied. The protein-protein interaction (PPI) network was constructed, and screened for the hub genes. Finally, Gene Set Enrichment Analysis (GSEA) was performed. In EBV-positive PBL, the immune-related pathway is upregulated and Cluster of differentiation 27 (CD27) and programmed cell death-ligand 1 (PD-L1) are hub genes. In EBV-positive PBL, EBV may affect tumorigenesis through activation of immune-related pathways and upregulation of CD27, PD-L1. Immune checkpoint blockers of CD70/CD27 and programmed cell death 1 (PD-1)/PD-L1 pathways may be one of the effective strategies for the treatment of EBV-positive PBL.

Targeting STING Activation by Antigen-Inspired MnO2 Nanovaccines Optimizes Tumor Radiotherapy.

Immune checkpoint blockers therapy can improve the radiotherapy-induced immunosuppression by enhancing interferon secretion, but still suffer from low clinical response rate and potential adverse effects. Mn2+ -mediated activation of interferon gene stimulator (STING) pathway provides an alternative for combination radioimmunotherapy of tumor. However, it is still a challenge for specific delivery of Mn2+ to innate immune cells and targeting activation of STING pathway. Herein, a novel antigen-inspired MnO2 nanovaccine is fabricated as Mn2+ source and functionalized with mannose, enabling it to target innate immune cells to activate the STING pathway. Meanwhile, the release of Mn2+ in the intracellular lysosomes can also be for magnetic resonance imaging to monitor the dynamic distribution of nanovaccines in vivo. The targeting activation of STING pathway can enhance radiotherapy-induced immune responses for inhibiting local and distant tumors, and resisting tumor metastasis. The study proposes an optimized radiotherapy strategy through targeting STING activation of antigen-inspired nanovaccines.

Guadecitabine increases response to combined anti-CTLA-4 and anti-PD-1 treatment in mouse melanoma in vivo by controlling T-cells, myeloid derived suppressor and NK cells

BackgroundThe combination of Programmed Cell Death 1 (PD-1) and Cytotoxic T-Lymphocyte Antigen 4 (CTLA-4) blockade has dramatically improved the overall survival rate for malignant melanoma. Immune checkpoint blockers (ICBs) limit the tumor’s immune escape yet only for approximately a third of all tumors and, in most cases, for a limited amount of time. Several approaches to overcome resistance to ICBs are being investigated among which the addition of epigenetic drugs that are expected to act on both immune and tumor cells. Guadecitabine, a dinucleotide prodrug of a decitabine linked via phosphodiester bond to a guanosine, showed promising results in the phase-1 clinical trial, NIBIT-M4 (NCT02608437).MethodsWe used the syngeneic B16F10 murine melanoma model to study the effects of immune checkpoint blocking antibodies against CTLA-4 and PD-1 in combination, with and without the addition of Guadecitabine. We comprehensively characterized the tumor’s and the host’s responses under different treatments by flow cytometry, multiplex immunofluorescence and methylation analysis.ResultsIn combination with ICBs, Guadecitabine significantly reduced subcutaneous tumor growth as well as metastases formation compared to ICBs and Guadecitabine treatment. In particular, Guadecitabine greatly enhanced the efficacy of combined ICBs by increasing effector memory CD8+ T cells, inducing effector NK cells in the spleen and reducing tumor infiltrating regulatory T cells and myeloid derived suppressor cells (MDSC), in the tumor microenvironment (TME). Guadecitabine in association with ICBs increased serum levels of IFN-γ and IFN-γ-induced chemokines with anti-angiogenic activity. Guadecitabine led to a general DNA-demethylation, in particular of sites of intermediate methylation levels.ConclusionsThese results indicate Guadecitabine as a promising epigenetic drug to be added to ICBs therapy.

Lymphoid tissue inducer cells in cancer: a potential therapeutic target.

Tumor cells are dynamic in nature; these cells first acquire immune surveillance and then escape from the immune system. Hence, progressed cancer cells distribute and metastasize to other organs via blood vessels as well as from the lymphatic system. Prognosis and treatment of metastatic cancer patients remain a major challenge nowadays. Till now, lots of target -based and immune checkpoint blocker therapies are used to treat disease patients. But these therapies fail to control the dissemination and metastasis of cancer. Before designing a treatment regimen for metastatic patients, understanding the mechanism of tumor cells spreading within lymph vessels remain undetermined. Construction of lymphoid structures since embryonic to adult stage are depend upon LTi. Foundation of lymph node, payer patches and TLO is initiated and regulated through these cells in any part of the body. During tumor growth, newly developed lymph node contained MDSCs and Treg cells which inhibit the immune response and promote tumor invasion and metastasis. LTi reconstituted lymph node can be used for both early and high risk detection of cancers. High and low risk of tumor growth and invasion depend upon the location and composition of immune cells within lymph nodes. However, LTi are not reported as predictive marker in cancer till date. Recent reports in cancer indicate that LTi cells are engaged in the spreading of tumor cells into a lymphatic vessel. Through this review we are trying to brief the development and role of the LTi in immune system during homeostasis and cancer.

Abstract P3-06-05: Effects of isoflavone genistein, combined with anti-estrogen fulvestrant, on anti-PD1 therapy response against E0771 mammary tumors in mice

Abstract Although immune checkpoint blockers (ICBs) have revolutionized the treatment of many cancers, only less than 30% of patients respond to any ICB as a monotherapy. Estrogens, produced by the adipose tissue in the mammary glands, are immunomodulators in the tumor microenvironment (TME). Estrogens suppress anti-tumor immunity and activate immunosuppression through the estrogen receptor α (ERα) in the immune cells but activate anti-tumor immunity through ERβ. Genistein (GEN) is a biologically active isoflavone and is structurally similar to estradiol (E2). However, in contrast to E2, GEN binds preferentially to ERβ. Here we studied if GEN combined with ERα inhibitor fulvestrant (Fulv) alters response to anti-PD1 therapy in ERα negative, ERβ positive E0771 mouse mammary tumors. Syngeneic C57BL/6 mice were fed either a control (CON) diet or GEN supplemented diet for 5 weeks and then allografted E0771 mammary tumor cell into the 4th mammary fat pad. When tumors reached an average size of 16mm2, mice in both diet groups were further divided into 4 sub-groups treated with: 1) anti-PD1 (150µg or 100µg every 3 days for a total of 3 doses), 2) Fulv (1mg) once weekly, 3) anti-PD1+Fulv or 4) IgG control group. We found that three doses of 150µg of anti-PD1 alone effectively reduced tumor growth in the CON (p=0.0005) group and its efficacy was notably weakened in the GEN group (p=0.04).. Combination with Fulv did not improve PD1 response. These findings suggest that when using a highly effective anti-PD1 dose, GEN may reduce rather than improve the response, and anti-ERα does not add to anti-PD1’s effect in control of GEN group. A suboptimal dose (100 µg) of anti-PD1 alone did not inhibit E0771 tumor growth in mice fed CON diet, but in the GEN group the tumor inhibition by anti-PD1 alone almost reached statistical significance (p=0.057). The combination of suboptimal PD1+Fulv significantly reduced tumor growth compared with IgG (p=0.04) or Fulv (p=0.02). During GEN feeding, anti-PD1+Fulv was even more potent in inhibiting tumor growth when compared with IgG group (p=0.02) and Fulv group (p=0.007). Thus, when anti-PD1 alone is not effective, either Fulv or GEN will improve responsiveness to anti-PD1. In the suboptimal anti-PD1 dose experiment, GEN feeding increased CD8+ T cells (P=0.04) and decreased CD4+Foxp3+ cells (p=0.01) in the TME. Further, GEN reduced the proportion of immunosuppressive MDSC cells (CD3-CD11B+Ly6Ghigh6Clow) in the PD1+ Fulv group (p=0.01) in the Peyer’s patches. In vitro experiments showed that both GEN and Fulv, and especially their combination, inhibited the E0771 cells proliferation, indicating that these two treatments can also directly suppress the growth of ERα negative but ERβ positive breast cancer cells. Taken together, the data show that anti-estrogens and GEN in the diet may improve response to anti-PD1 therapy, possibly both through activation of tumor immune response and inhibition of tumor cell proliferation and induction of tumor cell death. Citation Format: Fabia de Oliveira Andrade, Vivek Verma, Ester Molina Hoyo, Karla Andrade de Oliveira, Pal Koak, Lu Jin, Leena Hilakivi-Clarke. Effects of isoflavone genistein, combined with anti-estrogen fulvestrant, on anti-PD1 therapy response against E0771 mammary tumors in mice [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P3-06-05.

41P BRCA2 pathogenic variant (PV): A novel agnostic biomarker for immune checkpoint blockers (ICB)?

41P BRCA2 pathogenic variant (PV): A novel agnostic biomarker for immune checkpoint blockers (ICB)?

Advanced Biomaterials with Intrinsic Immunomodulation Effects for Cancer Immunotherapy.

In recent years, tumor immunotherapy has achieved significant success in tumor treatment based on immune checkpoint blockers and chimeric antigen receptor T-cell therapy. However, about 70-80% of patients with solid tumors do not respond to immunotherapy due to immune evasion. Recent studies found that some biomaterials have intrinsic immunoregulatory effects, except serve as carriers for immunoregulatory drugs. Moreover, these biomaterials have additional advantages such as easy functionalization, modification, and customization. In this review, the recent advances of these immunoregulatory biomaterials in cancer immunotherapy and their interaction with cancer cells, immune cells, and the immunosuppressive tumor microenvironment are summarized. Finally, the opportunities and challenges of immunoregulatory biomaterials used in the clinic and the prospect of their future in cancer immunotherapy are discussed.

Visceral adipose tissue secretome from early and late-stage oesophageal cancer patients differentially affects effector and regulatory T cells

AimVisceral obesity is a key risk factor in the development of oesophagogastric junctional adenocarcinoma (OGJ), predominantly via generation of systemic low grade inflammation. Obesity-induced inflammation promotes resistance to current standards of care, enhancing tumour cell growth and survival. This study investigates the effect of the visceral adipose tissue secretome from OGJ patients with early versus advanced tumours on T-cell immunity and the role of immune checkpoint blockade in enhancing anti-tumour immunity.Methods and resultsVisceral adipose conditioned media (ACM) from both early and late-stage OGJ patients significantly altered T cell activation status, upregulating co-stimulatory marker CD27 on T cells. ACM from both early and late-stage OGJ patients significantly altered immune checkpoint expression profiles downregulating immune checkpoints (ICs) on the surface of dual Th1/17-like and Th17-like cells and upregulating ICs on the surface of Th1-like cells and Treg cells. ACM derived from early-stage OGJ patients but not late-stage OGJ patients increased IFN-γ production by T cells. The addition of immune checkpoint blockers (ICBs) did not increase IFN-γ production by T cells in the presence of late-stage ACM, collectively highlighting the dichotomous immunostimulatory effect of early-stage ACM and immune-inhibitory effect of late-stage ACM. Interestingly, ACM from early-stage OGJ patients was more pro-inflammatory than ACM from late-stage patients, reflected by decreased levels of IL-17A/F, TNF-α, IL-1RA and IL-5.ConclusionThe ACM-induced upregulation of ICs on T cells highlights a therapeutic vulnerability that could be exploited by ICBs to harness anti-cancer immunity and improve clinical outcomes for OGJ patients.Graphical Schematic workflow – (A) visceral adipose tissue was taken from OAC patients at time of surgery and cultured for 72 h in media. (B) The harvested ACM was co-cultured with healthy donor PBMCs that were concurrently activated with anti-CD3/28 for 48 h and T cell immunophenotyping was carried out by flow cytometry. Key findings – (A) Early and late stage ACM enhanced a Th1-like phenotype and upregulated CTLA-4 on Th1-like cells. A Th17-like phenotype was also enhanced in addition with a Treg-like phenotype. CTLA-4 and PD-L1 were upregulated on the surface of Treg-like cells. (B) ICB-attenuated IL-17 production by T cells. However, ACM attenuated ICB-mediated reduction in IL-10 production by T cells. Higher levels of pro-inflammatory factors were found in early stage ACM compared with late stage ACM.

Enhancing Skin Cancer Immunotheranostics and Precision Medicine through Functionalized Nanomodulators and Nanosensors: Recent Development and Prospects.

Skin cancers, especially melanomas, present a formidable diagnostic and therapeutic challenge to the scientific community. Currently, the incidence of melanomas shows a high increase worldwide. Traditional therapeutics are limited to stalling or reversing malignant proliferation, increased metastasis, or rapid recurrence. Nonetheless, the advent of immunotherapy has led to a paradigm shift in treating skin cancers. Many state-of-art immunotherapeutic techniques, namely, active vaccination, chimeric antigen receptors, adoptive T-cell transfer, and immune checkpoint blockers, have achieved a considerable increase in survival rates. Despite its promising outcomes, current immunotherapy is still limited in its efficacy. Newer modalities are now being explored, and significant progress is made by integrating cancer immunotherapy with modular nanotechnology platforms to enhance its therapeutic efficacy and diagnostics. Research on targeting skin cancers with nanomaterial-based techniques has been much more recent than other cancers. Current investigations using nanomaterial-mediated targeting of nonmelanoma and melanoma cancers are directed at augmenting drug delivery and immunomodulation of skin cancers to induce a robust anticancer response and minimize toxic effects. Many novel nanomaterial formulations are being discovered, and clinical trials are underway to explore their efficacy in targeting skin cancers through functionalization or drug encapsulation. The focus of this review rivets on theranostic nanomaterials that can modulate immune mechanisms toward protective, therapeutic, or diagnostic approaches for skin cancers. The recent breakthroughs in nanomaterial-based immunotherapeutic modulation of skin cancer types and diagnostic potentials in personalized immunotherapies are discussed.

Losartan controls immune checkpoint blocker-induced edema and improves survival in glioblastoma mouse models

Immune checkpoint blockers (ICBs) have failed in all phase III glioblastoma trials. Here, we found that ICBs induce cerebral edema in some patients and mice with glioblastoma. Through single-cell RNA sequencing, intravital imaging, and CD8+ T cell blocking studies in mice, we demonstrated that this edema results from an inflammatory response following antiprogrammed death 1 (PD1) antibody treatment that disrupts the blood-tumor barrier. Used in lieu of immunosuppressive corticosteroids, the angiotensin receptor blocker losartan prevented this ICB-induced edema and reprogrammed the tumor microenvironment, curing 20% of mice which increased to 40% in combination with standard of care treatment. Using a bihemispheric tumor model, we identified a "hot" tumor immune signature prior to losartan+anti-PD1 therapy that predicted long-term survival. Our findings provide the rationale and associated biomarkers to test losartan with ICBs in glioblastoma patients.

Solute Carrier Family 7 Member 11 (SLC7A11) is a Potential Prognostic Biomarker in Uterine Corpus Endometrial Carcinoma.

Uterine corpus endometrial carcinoma (UCEC) is a common type of gynecological cancers, second only to cervical cancer in incidence.Thus, it is necessary to develop effective therapies and identify biomarkers for its prognosis.Solute carrier family 7 member 11 (SLC7A11) is well known for its role in maintaining the intracellular glutathione level and preventing oxidative-stress-induced cell death. However, the association between SLC7A11 expression and prognosis as well as the correlation between tumor-infiltrating immune cells (TIICs) and immunotherapy of UCEC has rarely been reported. This study aims to evaluate the prognostic significance and immune cell infiltration level of SLC7A11 in UCEC. Bioinformatics analysis tools and databases, including R software, National Center for Biotechnology Information (NCBI), The Cancer Genome Atlas (TCGA), GEPIA2, Sangerbox, Kaplan-Meier (K-M) Plotter, TISIDB, and TIMER2, were utilized to measure the expression level and clarify the clinical significance of SLC7A11 in UCEC. SLC7A11 expression was dramatically up-regulated in UCEC patients and associated with prognosis.DNA methylation levels in the SLC7A11-promoter region were significantly higher in normal participants than in patients with UCEC. We also showed that SLC7A11 overexpression was associated with TIICs, immune checkpoint blockers (ICBs), and immunotherapy response in UCEC. The half-maximal inhibitory concentration (IC50) results obtained with the cohort from TCGA showed that Z-VAD-FMK (Caspase inhibitor), S-Triphenylmethyl-L-cysteine (S-Trityl-L-cysteine), and TAE684 (ALK inhibitor) had higher IC50 values in low-expression patient (p < 0.05). SLC7A11 overexpression is associated with favorable prognosis of patients with UCEC and is associated with TIICs and the responses to immunotherapy.

DSP-0509, a systemically available TLR7 agonist, exhibits combination effect with immune checkpoint blockade by activating anti-tumor immune effects.

TLR7 is an innate immune receptor that recognizes single-stranded RNAs, and its activation leads to anti-tumor immune effects. Although it is the only approved TLR7 agonist in cancer therapy, imiquimod is allowed to be administered with topical formulation. Thus, systemic administrative TLR7 agonist is expected in terms of expanding applicable cancer types. Here, we demonstrated the identification and characterization of DSP-0509 as a novel small-molecule TLR7 agonist. DSP-0509 is designed to have unique physicochemical features that could be administered systemically with a short half-life. DSP-0509 activated bone marrow-derived dendritic cells (BMDCs) and induced inflammatory cytokines including type I interferons. In the LM8 tumor-bearing mouse model, DSP-0509 reduced tumor growth not only in subcutaneous primary lesions but also in lung metastatic lesions. DSP-0509 inhibited tumor growth in several syngeneic tumor-bearing mouse models. We found that the CD8+ T cell infiltration of tumor before treatment tended to be positively correlated with anti-tumor efficacy in several mouse tumor models. The combination of DSP-0509 with anti-PD-1 antibody significantly enhanced the tumor growth inhibition compared to each monotherapy in CT26 model mice. In addition, the effector memory T cells were expanded in both the peripheral blood and tumor, and rejection of tumor re-challenge occurred in the combination group. Moreover, synergistic anti-tumor efficacy and effector memory T cell upregulation were also observed for the combination with anti-CTLA-4 antibody. The analysis of the tumor-immune microenvironment by using the nCounter assay revealed that the combination of DSP-0509 with anti-PD-1 antibody enhanced infiltration by multiple immune cells including cytotoxic T cells. In addition, the T cell function pathway and antigen presentation pathway were activated in the combination group. We confirmed that DSP-0509 enhanced the anti-tumor immune effects of anti-PD-1 antibody by inducing type I interferons via activation of dendritic cells and even CTLs. In conclusion, we expect that DSP-0509, a new TLR7 agonist that synergistically induces anti-tumor effector memory T cells with immune checkpoint blockers (ICBs) and can be administered systemically, will be used in the treatment of multiple cancers.

Cuproptosis-related gene FDX1 as a prognostic biomarker for kidney renal clear cell carcinoma correlates with immune checkpoints and immune cell infiltration.

Background: Kidney renal clear cell carcinoma (KIRC) is not sensitive to radiotherapy and chemotherapy, and only some KIRC patients can benefit from immunotherapy and targeted therapy. Cuproptosis is a new mechanism of cell death, which is closely related to tumor progression, prognosis and immunity. The identification of prognostic markers related to cuproptosis in KIRC may provide targets for treatment and improve the prognosis of KIRC patients. Methods: Ten cuproptosis-related genes were analyzed for differential expression in KIRC-TCGA and a prognostic model was constructed. Nomogram diagnostic model was used to screen independent prognostic molecules. The screened molecules were verified in multiple datasets (GSE36895 and GSE53757), and in KIRC tumor tissues by RT-PCR and immunohistochemistry (IHC). Clinical correlation of cuproptosis-related independent prognostic molecules was analyzed. According to the molecular expression, the two groups were divided into high and low expression groups, and the differences of immune checkpoint and tumor infiltrating lymphocytes (TILs) between the two groups were compared by EPIC algorithm. The potential Immune checkpoint blocking (ICB) response of high and low expression groups was predicted by the "TIDE" algorithm. Results: FDX1 and DLAT were protective factors, while CDKN2A was a risk factor. FDX1 was an independent prognostic molecule by Nomogram, and low expressed in tumor tissues compared with adjacent tissues (p < 0.05). FDX1 was positively correlated with CD274, HAVCR2, PDCD1LG2, and negatively correlated with CTLA4, LAG3, and PDCD1. The TIDE score of low-FDX1 group was higher than that of high-FDX1 group. The abundance of CD4+ T cells, CD8+ T cells and Endothelial cells in FDX1-low group was lower than that in FDX1-high group (p < 0.05). Conclusion: FDX1, as a key cuproptosis-related gene, was also an independent prognostic molecule of KIRC. FDX1 might become an interesting biomarker and potential therapeutic target for KIRC.

DNA Nanomaterials-Based Platforms for Cancer Immunotherapy.

The past few decades have witnessed the evolving paradigm for cancer therapy from nonspecific cytotoxic agents to selective, mechanism-based therapeutics, especially immunotherapy. In particular, the integration of nanomaterials with immunotherapy is proven to improve the therapeutic outcome and minimize off-target toxicity in the treatment. As a novel nanomaterial, DNA-based self-assemblies featuring uniform geometries, feasible modifications, programmability, surface addressability, versatility, and intrinsic biocompatibility, are extensively exploited for innovative and effective cancer immunotherapy. In this review, the successful employment of DNA nanoplatforms for cancer immunotherapy, including the delivery of immunogenic cell death inducers, adjuvants and vaccines, immune checkpoint blockers as well as the application in immune cell engineering and adoptive cell therapy is summarized. The remaining challenges and future perspectives regarding the pharmacokinetics/pharmacodynamics, in vivo fate and immunogenicity of DNA materials, and the design of intelligent DNA nanomedicine for individualized cancer immunotherapy are also discussed.

Abstract A027: Clonal hematopoiesis of indeterminate potential (CHIP) in patients with advanced NSCLC treated with immune checkpoint blockers (ICB) as monotherapy: Analysis of the PREMIS study. [R

Abstract Introduction: Immunotherapy is one of the mainstays of lung cancer treatment. The results presented in pivotal trials do not always reflect real life, since patients (pts) are more selected for prognostic factors. Cancer is associated with advanced age and aging is the main risk factor for developing CHIP, which refers to the finding of one or more mutations affecting genes involved in hematologic malignancies in pts without hematologic disease per se. Objective: To evaluate CHIP prevalence in a prospective cohort of 104 pts treated with ICB for NSCLC and to correlate CHIP and clinical outcomes. Materials and methods: We performed a Next-Generation Sequencing (NGS) with a panel of 74-genes dedicated to hematological alteration on DNA extracted from whole blood collected before the first administration of an ICB, within the PREMIS trial (NCT03984318). To estimate the prevalence of CHIP, we selected the following 4 CHIP genes; DNMT3A, TET2, ASXL1 and JAK2. CHIP prevalence was assessed according to two variant allele frequency (VAF) thresholds (1% and 2%). The results were analyzed for the entire population and for the subgroup of pts older than 70 years. Results: We included 104 pts; 68 pts (65%) male, median age of 68 years [range 31-87] and adenocarcinoma represented the 68%. PD-L1 &amp;lt;50%: 28% and &amp;gt;50%: 43%. ICB setting was 1°L 41%; 2°L 47%; &amp;gt; 3°L 11%, and the most used ICB was Pembrolizumab in 63% of pts. Among the 88% of the pts who discontinued treatment, 63% did it due to disease progression and 13% due to toxicity (pneumonitis was the most frequent adverse event in pts with CHIP). Overall, at least 1 CHIP mutation was found in 35 pts (34%). Incidence at VAF 1% and 2% for each mutation were DNMT3A 80% and 69%, TET2 11% respectively, ASXL1 11% respectively and JAK2 6% and 3%; for older pts subgroup VAF at 1% and 2% were: DNMT3A 71% and 59% and for TET2 and ASXL1 24% respectively for each mutation. Only 4% of pts had more than 1 CHIP mutation. No pts developed hematological disease during the follow up. There was no difference in CHIP prevalence according to line of treatment. CHIP pts achieved disease control in 51%. PFS and OS results will be presented at the conference. Conclusion: CHIP is commonly found in pts with solid tumors, including NSCLC, with a prevalence in our cohort of 34%, which is lower than that reported in literature. No pts developed a characterized hematological disease during follow up. Survival outcomes will be presented at the conference. Citation Format: Julieta Elena Rodriguez, Capucine Baldini, Francois Xavier Danlos, Aurelien Marabelle, Maxime Frelaut, Marco Tagliamento, Mihaela Aldea, Benjamin Besse, Jean Baptiste Micol, Christophe Marzac, Nathalie Chaput, Christophe Massard. Clonal hematopoiesis of indeterminate potential (CHIP) in patients with advanced NSCLC treated with immune checkpoint blockers (ICB) as monotherapy: Analysis of the PREMIS study. [R] [abstract]. In: Proceedings of the AACR Special Conference: Aging and Cancer; 2022 Nov 17-20; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_1):Abstract nr A027.

Abstract IA020: Improving treatment of primary and metastatic brain tumors: Emerging insights and novel strategies

Abstract Approximately 200,000 patients develop metastasis each year in US alone. This incidence is approximately 20 times higher than glioblastoma – a uniformly fatal disease where all Phase III immune-checkpoint trials have failed to date. Patients diagnosed with metastatic breast cancer have a median survival of two years and account for approximately 40,000 deaths annually in the US alone. About 1/3rd of women with advanced breast cancer are at risk of developing brain metastases (BMs). A notable example is human epidermal growth factor receptor 2 (HER2)-positive breast cancer, where BMs from this disease are refractory to drugs that otherwise control disease in extracranial sites, for two reasons: i) the blood-brain/blood-tumor barrier (BBB/BTB) hinders the delivery of drugs to BMs, and ii) the brain tumor microenvironment (TME) reduces the efficacy of these therapies even when they accrue in BMs (Arvanitis et al, Nature Reviews Cancer 2020). By employing clinically relevant murine models, we demonstrated that theanti-HER2 antibody trastuzumab can upregulate VEGF in the microenvironment of BM (Izumi et al, Nature 2002), and thus, adding anti-VEGF/R agents can improve the efficacy of anti-HER2 therapies (Kodack et al, PNAS 2012). We further showed that HER3 is overexpressed in BMs and confers de novo resistance to anti-HER2 therapies. Blocking HER3 enhanced the efficacy of FDA-approved targeted therapies including trastuzumab and neratinib - a finding supported by independent clinical trials (Kodack et al, Science Translational Medicine 2017). In our attempt to improve survival further, we discovered that breast cancer cells implanted in the brain exhibit increased de novo lipid synthesis compared to breast cancer cells implanted in the breast or liver. Genetic or pharmacological inhibition of fatty acid synthase (FASN) reducesHER2+ breast tumor growth in the brain – unlike those grown in the breast or liver, demonstrating that differences in nutrient availability across metastatic sites can result in targetable metabolic dependencies (Ferraro et al, Nature Cancer 2021). In parallel, we have employed focused ultrasound to improve delivery of various therapeutics to BMs by transiently disrupting BBB/BTB (Arvanitis et al, PNAS 2018). Finally, by recognizing the similarities between the TME of BM and glioblastoma, we have developed 3 new strategies to reprogram the immunosuppressive microenvironment of glioblastoma to improve the efficacy of immune-check point blockers against these uniformly fatal tumors (Amoozgar et al, Nature Communications 2021, Amoozgar et al, bioarxiv 2022, Datta et al. bioarxiv 2022). These strategies are likely to also benefit patients with brain metastases that have now become a leading cause of morbidity and mortality with improved detection and extracranial treatments. Citation Format: Rakesh K. Jain. Improving treatment of primary and metastatic brain tumors: Emerging insights and novel strategies [abstract]. In: Proceedings of the AACR Special Conference: Cancer Metastasis; 2022 Nov 14-17; Portland, OR. Philadelphia (PA): AACR; Cancer Res 2022;83(2 Suppl_2):Abstract nr IA020.