Drug response to PD-1/PD-L1 blockade: based on biomarkers

Enhancing cancer immunotherapy: Exploring strategies to target the PD-1/PD-L1 axis and analyzing the associated patent, regulatory, and clinical trial landscape

Cancer treatment modalities and their progression is guided by the specifics of cancer, including its type and site of localization. Surgery, radiation, and chemotherapy are the most often used conventional treatments. Conversely, emerging treatment techniques include immunotherapy, hormone therapy, anti-angiogenic therapy, dendritic cell-based immunotherapy, and stem cell therapy. Immune checkpoint inhibitors' anticancer properties have drawn considerable attention in recent studies in the cancer research domain. Programmed Cell Death Protein-1 (PD-1) and its ligand (PD-L1) checkpoint pathway are key regulators of the interactions between activated T-cells and cancer cells, protecting the latter from immune destruction. When the ligand PD-L1 attaches to the receptor PD-1, T-cells are prevented from destroying cells that contain PD-L1, including cancer cells. The PD-1/PD-L1 checkpoint inhibitors block them, boosting the immune response and strengthening the body's defenses against tumors. Recent years have seen incredible progress and tremendous advancement in developing anticancer therapies using PD-1/PD-L1 targeting antibodies. While immune-related adverse effects and low response rates significantly limit these therapies, there is a need for research on methods that raise their efficacy and lower their toxicity. This review discusses various recent innovative nanomedicine strategies such as PLGA nanoparticles, carbon nanotubes and drug loaded liposomes to treat cancer targeting PD-1/PD-L1 axis. The biological implications of PD-1/PD-L1 in cancer treatment and the fundamentals of nanotechnology, focusing on the novel strategies used in nanomedicine, are widely discussed along with the corresponding guidelines, clinical trial status, and the patent landscape of such formulations.

Biomarkers and computational models for predicting efficacy to tumor ICI immunotherapy

Numerous studies have shown that immune checkpoint inhibitor (ICI) immunotherapy has great potential as a cancer treatment, leading to significant clinical improvements in numerous cases. However, it benefits a minority of patients, underscoring the importance of discovering reliable biomarkers that can be used to screen for potential beneficiaries and ultimately reduce the risk of overtreatment. Our comprehensive review focuses on the latest advancements in predictive biomarkers for ICI therapy, particularly emphasizing those that enhance the efficacy of programmed cell death protein 1 (PD-1)/programmed cell death-ligand 1 (PD-L1) inhibitors and cytotoxic T-lymphocyte antigen-4 (CTLA-4) inhibitors immunotherapies. We explore biomarkers derived from various sources, including tumor cells, the tumor immune microenvironment (TIME), body fluids, gut microbes, and metabolites. Among them, tumor cells-derived biomarkers include tumor mutational burden (TMB) biomarker, tumor neoantigen burden (TNB) biomarker, microsatellite instability (MSI) biomarker, PD-L1 expression biomarker, mutated gene biomarkers in pathways, and epigenetic biomarkers. TIME-derived biomarkers include immune landscape of TIME biomarkers, inhibitory checkpoints biomarkers, and immune repertoire biomarkers. We also discuss various techniques used to detect and assess these biomarkers, detailing their respective datasets, strengths, weaknesses, and evaluative metrics. Furthermore, we present a comprehensive review of computer models for predicting the response to ICI therapy. The computer models include knowledge-based mechanistic models and data-based machine learning (ML) models. Among the knowledge-based mechanistic models are pharmacokinetic/pharmacodynamic (PK/PD) models, partial differential equation (PDE) models, signal networks-based models, quantitative systems pharmacology (QSP) models, and agent-based models (ABMs). ML models include linear regression models, logistic regression models, support vector machine (SVM)/random forest/extra trees/k-nearest neighbors (KNN) models, artificial neural network (ANN) and deep learning models. Additionally, there are hybrid models of systems biology and ML. We summarized the details of these models, outlining the datasets they utilize, their evaluation methods/metrics, and their respective strengths and limitations. By summarizing the major advances in the research on predictive biomarkers and computer models for the therapeutic effect and clinical utility of tumor ICI, we aim to assist researchers in choosing appropriate biomarkers or computer models for research exploration and help clinicians conduct precision medicine by selecting the best biomarkers.

Comprehensive analysis of single-cell and bulk RNA-sequencing data identifies B cell marker genes signature that predicts prognosis and analysis of immune checkpoints expression in head and neck squamous cell carcinoma

Recent studies have shown that B cells and the associated tertiary lymphoid structures (TLS) correlate with the response of patients to immune checkpoint inhibitors (ICIs) and predict overall survival (OS) in cancer patients. We screened 145 B cell marker genes (BCMG) by a comprehensive analysis of single-cell RNA-sequencing (scRNA-seq) data of head and neck squamous cell carcinoma (HNSC) from the Gene Expression Omnibus (GEO) database. The BCMG signature (BCMGS) was established using The Cancer Genome Atlas (TCGA) dataset of HNSC and verified in four independent datasets. The multivariate Cox regression analysis identified the signature as an independent prognostic factor. A prognostic nomogram was constructed with independent prognostic factors using the TCGA dataset. GO and KEGG analysis revealed the underlying signaling pathways related to this signature. Study of immune profiles showed that patients in the low-risk group presented discriminative immune-cell infiltrations. Furthermore, the low-risk group was featured by higher TCR and BCR diversity, which suggested that low-risk patients may be more sensitive to ICIs. Immunohistochemistry was performed, and we found that high expression of FTH1 was significantly correlated with poor OS (P = 0.025). The expression of TIM-3, LAG-3 and PD-1 was positively correlated and associated with better OS in HNSC. However, there was no statistically significant difference between PD-L1, PD-L2, CTLA-4, TIGIT and prognosis. The BCMGS was a promising prognostic biomarker in HNSC, which may help to interpret the responses to immunotherapy and provide a new perspective for future research on the treatment in HNSC.

An integrated computational strategy to predict personalized cancer drug combinations by reversing drug resistance signatures

Drug resistance currently poses the greatest barrier to cancer treatments. To overcome drug resistance, drug combination therapy has been proposed as a promising treatment strategy. Herein, we present Re-Sensitizing Drug Prediction (RSDP), a novel computational strategy, for predicting the personalized cancer drug combination A + B by reversing the resistance signature of drug A. The process integrates multiple biological features using a robust rank aggregation algorithm, including Connectivity Map, synthetic lethality, synthetic rescue, pathway, and drug target. Bioinformatics assessments revealed that RSDP achieved a relatively accurate prediction performance for identifying personalized combinational re-sensitizing drug B against cell line-specific intrinsic resistance, cell line-specific acquired resistance, and patient-specific intrinsic resistance to drug A. In addition, we developed the largest resource of cell line-specific cancer drug resistance signatures, including intrinsic and acquired resistance, as a byproduct of the proposed strategy. The findings indicate that personalized drug resistance signature reversal is a promising strategy for identifying personalized drug combinations, which may guide future clinical decisions regarding personalized medicine.

Monalizumab efficacy correlates with HLA-E surface expression and NK cell activity in head and neck squamous carcinoma cell lines

PURPOSE

NKG2A, an inhibitory receptor expressed on NK cells and T cells, leads to immune evasion by binding to HLA-E expressed on cancer cells. Here, we investigated the relationship between HLA-E surface expression on head and neck squamous cell carcinoma (HNSCC) cell lines and the efficacy of monalizumab, an NKG2A inhibitor, in promoting NK cell activity.

METHODS

Six HNSCC cell lines were used as target cells. After exposure to IFN- γ, HLA-E surface expression on HNSCC cell lines was measured by flow cytometry. Peripheral blood mononuclear cells (PBMCs) from healthy donors and isolated NK cells were used as effector cells. NK cells were stimulated by treatment with IL-2 and IL-15 for 5 days, and NK cell-induced cytotoxicity was analyzed by CD107a degranulation and 51Cr release assays.

RESULTS

We confirmed that HLA-E expression was increased by IFN-γ secreted by NK cells and that HLA-E expression was different for each cell line upon exposure to IFN-γ. Cell lines with high HLA-E expression showed stronger inhibition of NK cell cytotoxicity, and efficacy of monalizumab was high. Combination with cetuximab increased the efficacy of monalizumab. In addition, stimulation of isolated NK cells with IL-2 and IL-15 increased the efficacy of monalizumab, even in the HLA-E low groups.

CONCLUSION

Monalizumab efficacy was correlated with HLA-E surface expression and was enhanced when NK cell activity was increased by cetuximab or cytokines. These results suggest that monalizumab may be potent against HLA-E-positive tumors and that monalizumab efficacy could be improved by promoting NK cell activity.

Nivolumab plus ipilimumab combination therapy in cancer: Current evidence to date

Immune checkpoint inhibitors (ICIs) have revolutionized cancer immunotherapy, yielding significant antitumor responses across multiple cancer types. Combination ICI therapy with anti-CTLA-4 and anti-PD-1 antibodies outperforms either antibody alone in terms of clinical efficacy. As a consequence, the U.S. Food and Drug Administration (FDA) approved ipilimumab (anti-CTLA-4) plus nivolumab (anti-PD-1) as the first-ever approved therapies for combined ICI in patients with metastatic melanoma. Despite the success of ICIs, treatment with checkpoint inhibitor combinations poses significant clinical challenges, such as increased rates of immune-related adverse events (irAEs) and drug resistance. Thus, identifying optimal prognostic biomarkers could help to monitor the safety and efficacy of ICIs and identify patients who may benefit the most from these treatments. In this review, we will first go over the fundamentals of the CTLA-4 and PD-1 pathways, as well as the mechanisms of ICI resistance. The results of clinical findings that evaluated the combination of ipilimumab and nivolumab are then summarized to support future research in the field of combination therapy. Finally, the irAEs associated with combined ICI therapy, as well as the underlying biomarkers involved in their management, are discussed.

Recent progress in cancer immunotherapy: Overview of current status and challenges

Cancer treatment is presently one of the most important challenges in medical science. Surgery, chemotherapy, radiotherapy, or combining these methods is used to eliminate the tumor. Hormone therapy, bone marrow transplantation, stem cell therapy as well as immunotherapy are other well-known therapeutic modalities. Immunotherapy, as the most important complementary method, uses the immune system for treating cancer followed by surgery, chemotherapy, and radiotherapy. This method is systematically used to prevent malignancies development mainly via potentiating antitumor immune cells activation and conversely compromising their exhaustion with the lowest negative effects on healthy cells. Active immunotherapy can be employed for cancer immunotherapy by directly using the ingredients of the immune system and activating immune responses. On the other hand, inactive immunotherapy is utilized by indirect induction and using immune cell-based products consisting of monoclonal antibodies. It has strongly been proved that combination therapy with immunotherapies and other therapeutic means, such as anti-angiogenic agents, could be a rational plan to treat cancer. Herein, we have focused on recent findings concerning the therapeutic merits of cancer therapy using immune checkpoint inhibitors (ICIs), adoptive cell transfer (ACT) and cancer vaccine alone or in combination with other approaches. Also, we offer a glimpse into the current challenges in this context.

DNA5mC Regulator-Mediated Molecular Clusters and Tumor Microenvironment Signatures in Glioblastoma

Growing evidence links DNA methylation to tumor immunity. The impact of DNA methylation (5 mC) on the microenvironment surrounding tumors and immunotherapy remains to be clarified. Through clustering gene expression of 20 DNA methylation regulators, this study aimed at systematically analyzing DNA methylation regulator patterns and tumor microenvironment characteristics of TCGA-GBM patients. Various subtypes of glioblastoma exhibit different tumor microenvironments and DNA methylation patterns. Each DNA methylation modification was then assigned a DNA methylation score (DMS). High DMS was associated with a good prognosis. In contrast, the low DMS group had a relatively low survival rate. A correlation was also found between high DMS and enhanced immunotherapy efficacy in two immune checkpoint blocking treatment cohorts. To conclude, identifying DNA methylation regulation patterns may prove critical to understanding glioblastoma progression and differentiation, as well as future therapeutic targets.

Immunotherapy in non-small cell lung cancer: Past, present, and future directions

Many decades in the making, immunotherapy has demonstrated its ability to produce durable responses in several cancer types. In the last decade, immunotherapy has shown itself to be a viable therapeutic approach for non-small cell lung cancer (NSCLC). Several clinical trials have established the efficacy of immune checkpoint blockade (ICB), particularly in the form of anti-programmed death 1 (PD-1) antibodies, anti-cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) antibodies and anti-programmed death 1 ligand (PD-L1) antibodies. Many trials have shown progression free survival (PFS) and overall survival (OS) benefit with either ICB alone or in combination with chemotherapy when compared to chemotherapy alone. The identification of biomarkers to predict response to immunotherapy continues to be evaluated. The future of immunotherapy in lung cancer continues to hold promise with the development of combination therapies, cytokine modulating therapies and cellular therapies. Lastly, we expect that innovative advances in technology, such as artificial intelligence (AI) and machine learning, will begin to play a role in the future care of patients with lung cancer.

Molecular profiles of endometrial cancer tumors among Black patients

OBJECTIVES

Disparate outcomes exist between Black and White patients with endometrial cancer (EC). One contributing factor is the disproportionately low representation of Black patients in clinical trials and in tumor molecular profiling studies. Our objective was to investigate molecular profiles of ECs in a cohort with a high proportion of tumors from Black patients.

METHODS

A total of 248 EC samples and self-reported race data were collected from 6 institutions. Comprehensive tumor profiling and analyses were performed by Caris Life Sciences.

RESULTS

Tumors from 105 (42%) Black and 143 (58%) White patients were included. Serous histology (58% vs 36%) and carcinosarcoma (25% vs 16%), was more common among Black patients, and endometrioid was less common (17% vs 48%) (p < 0.01). Differences in gene mutations between cohorts corresponded to observed histologic differences between races. Specifically, TP53 mutations were predominant in serous tumors. In endometrioid tumors, mutations in ARID1A were the most common, and high rates of MSI-H, MMRd, and TMB-H were observed. In carcinosarcoma tumors, hormone receptor expression was high in tumors of Black patients (PR 23.4%, ER 30.8%). When stratified by histology, there were no significant differences between tumors from Black and White women.

CONCLUSIONS

This cohort had a high proportion of tumors from Black women. Distinct molecular profiles were driven primarily by more aggressive histologic subtypes among Black women. Continued effort is needed to include Black women and other populations under-represented in EC molecular profiling studies as targeted therapies and personalized medicine become mainstream.

Constructing a Novel Signature Based on Immune-Related lncRNA to Improve Prognosis Prediction of Cervical Squamous Cell Carcinoma Patients

We downloaded gene expression data, clinical data, and somatic mutation data of cervical squamous cell carcinoma (CSCC) patients from The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) databases. Predictive lncRNAs were screened using univariate analysis and least absolute shrinkage and selection operator (LASSO) regression, and risk scores were calculated for each patient according to the expression levels of lncRNAs and regression coefficients to establish a risk model that could be a novel signature. We assessed the correlation between immune infiltration status, chemotherapeutics sensitivity, immune checkpoint proteins (ICP), and the signature. Therefore, we selected 11 immune-related lncRNAs (WWC2,AS2, STXBP5.AS1, ERICH6.AS1, USP30.AS1, LINC02073, RBAKDN, IL21R.AS1, LINC02078, DLEU1, LINC00426, BOLA3.AS1) to construct the risk model. Patients who were in the high-risk group had a shorter survival time than those in the low-risk group (p < 0.001). Risk scores in the signature were negatively correlated with macrophage M1, macrophage M2, and T cell CD8 + ; what's more, T cell CD8 + was higher in the low-risk group. The expression levels of ICP such as PD-L1, PD-1, CTLA-4, TIGIT, LAG-3, and TIM-3 were substantially higher in the low-risk group. For chemotherapeutic agents, high-risk scores were associated with higher half-inhibitory concentrations (IC50) of cisplatin. These findings suggested that the risk model can be a novel signature for predicting CSCC patients' prognosis, and it also can be used to formulate clinical treatment plans for CSCC patients.

Predictive molecular markers for the treatment with immune checkpoint inhibitors in colorectal cancer

Colorectal cancer is one of the most common malignant tumors and, hence, has become one of the most important public health issues in the world. Treatment with immune checkpoint inhibitors (ICIs) successfully improves the survival rate of patients with melanoma, non-small-cell lung cancer, and other malignancies, and its application in metastatic colorectal cancer is being actively explored. However, a few patients develop drug resistance. Predictive molecular markers are important tools to precisely screen patient groups that can benefit from treatment with ICIs. The current article focused on certain important predictive molecular markers for ICI treatment in colorectal cancer, including not only some of the mature molecular markers, such as deficient mismatch repair (d-MMR), microsatellite instability-high (MSI-H), tumor mutational burden (TMB), programmed death-ligand-1 (PD-L1), tumor immune microenvironment (TiME), and tumor-infiltrating lymphocytes (TILs), but also some of the novel molecular markers, such as DNA polymerase epsilon (POLE), polymerase delta 1 (POLD1), circulating tumor DNA (ctDNA), and consensus molecular subtypes (CMS). We have reviewed these markers in-depth and presented the results from certain important studies, which suggest their applicability in CRC and indicate their advantages and disadvantages. We hope this article is helpful for clinicians and researchers to systematically understand these markers and can guide the treatment of colorectal cancer.

B7-H4 is increased in lung adenocarcinoma harboring EGFR-activating mutations and contributes to immunosuppression

PD-1/PD-L1 inhibitors have shown clinical benefit in lung adenocarcinoma (LUAD). However, the immunotherapy strategy is less effective in patients with EGFR-activating mutations (EGFR MT). Studies showed that besides low expression of PD-L1, the absence of TILs and distinct expression profile of immune checkpoint molecules might be associated with low response of the patient subset. In this study, we first compared CD8A, GZMB and PRF1 mRNA levels in different LUAD subtypes harboring different driver mutations by dataset analyses and investigated the association between 15 well-defined B7-CD28 family members and driver mutations. The results showed that the decreases in the density and function of CD8⁺ TILs, CD274 (PD-L1 gene), and CD86 and increases in VTCN1 (B7-H4 gene) and HHLA2 were associated with LUAD with EGFR-activating mutations. Immunohistochemical staining studies further supported that PD-L1 was downregulated and B7-H4 was upregulated in the subtype. Furthermore, PD-L1 expression was positively associated with levels of CD8A and granzyme B, while B7-H4 expression was negatively associated with granzyme B levels. In lung cancer cell lines, EGFR-activating mutations effectively upregulated B7-H4 and downregulated PD-L1. MEK/ERK-pathway activation upregulated B7-H4, and PI3K/Akt activation upregulated PD-L1. EGFR 19Del mutation was associated with inhibition of CD8⁺ T-cell function, while knocking down B7-H4 could reverse the inhibition, and further showed tumor-growth inhibition and longer survival in vivo. Taken together, this study shed light on that B7-H4 might be an alternative immune-checkpoint molecule and a potential therapeutic target for LUAD with EGFR MT.

Potential Biomarkers for the Efficacy of PD-1-PD-L Blockade in Cancer

A decade ago, immune checkpoint blockade emerged as a major breakthrough in oncology, proposing a novel approach by which immune brakes could be released to enhance antitumor responses. Despite apparently modest improvement of the median duration of response, a spectacular doubling of long-term responses as compared to the available standard of care was seen, for instance, in metastatic melanoma. It soon became obvious that the percentage of patients responding to these novel approaches is relatively small, and the importance of an accurate prediction of responders became more and more clear. Strong predictive markers would allow for the administration of immune checkpoint blocker therapy to the patients most likely to benefit from it, and sparing the potential non-responders of a treatment which is far from innocuous, being associated with significant side-effects and, not least, an important price tag. A number of potential response predictors have already been investigated and partly validated, but they do not cover the major unmet need encountered in the current clinical setting. Here, we review biomarkers for immune checkpoint blockade efficacy, either clinically validated and currently in use, or which have been proposed as candidates and are currently under investigation.

PD-1/PD-L1 blockade: Prospectives for immunotherapy in cancer and autoimmunity

Immune checkpoint blockade therapy (ICBT) has become a successful cancer treatment approach in the field of cancer immunotherapy. Blockade of programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1) with monoclonal antibodies have been known as successful examples of cancer immunotherapy in recent years. Although ICBT has been shown to be beneficial in cancers, such benefits have only been seen in a portion of cancer patients. In this regard, enhancing the therapeutic effects of inhibiting PD-1 and PD-L1 and reducing the side effects of this approach can be considered as a potential approach in a successful ICBT. In this review, we have highlighted new viewpoints regarding improving the therapeutic effect of PD-1 and PD-L1 blockades in cancer therapy. Besides, their expression levels as a biomarker with prognostic value, their role in intestinal microbiota modulation, combination therapy, and immune-related side effects (irAEs) have been discussed.

Nuclear imaging-guided PD-L1 blockade therapy increases effectiveness of cancer immunotherapy

Objectives

Strategies to improve the responsiveness of programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) checkpoint blockade therapy remain an essential topic in cancer immunotherapy. In this study, we developed a new radiolabeled nanobody-based imaging probe ^99mTc-MY1523 targeting PD-L1 for the enhanced therapeutic efficacy of PD-L1 blockade immunotherapy by the guidance of ^99mTc-MY1523 SPECT/CT imaging.

Methods

The binding affinity and specificity of nanobody MY1523 were measured in vitro. MY1523 was radiolabeled with ^99mTc by a site-specific transpeptidation of Sortase-A, and the biodistribution and single photon emission CT (SPECT)/CT were performed in mice bearing different tumors. We used interferon-γ (IFN-γ) as an intervention means to establish animal models with different levels of PD-L1 expression, then investigated the ability of ^99mTc-MY1523 SPECT/CT for the in vivo non-invasive measurement of PD-L1 expression in tumors. Finally, the PD-L1 blockade immunotherapies guided by ^99mTc-MY1523 SPECT/CT were carried out in MC-38, A20, and 4T1 tumor-bearing mouse models, followed by the testing of tumor infiltration T cells.

Results

MY1523 exhibited a high binding affinity and specificity to PD-L1 and had no competitive binding with the therapeutic antibody. ^99mTc-MY1523 was prepared with high specific activity and radiochemical purity. It was found that tumor PD-L1 expression was dynamically upregulated by IFN-γ intervention in MC-38, A20, and 4T1 tumor-bearing mouse models, as indicated by ^99mTc-MY1523 SPECT/CT. The PD-L1 blockade therapy initiated during the therapeutic time window determined by ^99mTc-MY1523 SPECT/CT imaging significantly enhanced the therapeutic efficacy in all animal models, while the tumor growth was effectively suppressed, and the survival time of mice was evidently prolonged. A correlation between dynamically upregulated PD-L1 expression and improved PD-L1 blockade therapy effectiveness was revealed, and the markedly increased infiltration of effector T cells into tumors was verified after the imaging-guided therapy.

Conclusion

Our results demonstrated that ^99mTc-MY1523 SPECT/CT allowed a real-time, quantitative and dynamic mapping of PD-L1 expression in vivo, and the imaging-guided PD-L1 blockade immunotherapy significantly enhanced the therapeutic efficacy. This strategy merits translation into clinical practice for the better management of combination therapies with radiotherapy or chemotherapy.

Anti-tumor effects of NK cells and anti-PD-L1 antibody with antibody-dependent cellular cytotoxicity in PD-L1-positive cancer cell lines

Background

Although programmed cell death-1/programmed death-ligand 1 (PD-L1) inhibitors show remarkable antitumor activity, a large portion of patients with cancer, even those with high PD-L1-expressing tumors, do not respond to their effects. Most PD-L1 inhibitors contain modified fragment crystallizable region (Fc) receptor binding sites to prevent antibody-dependent cellular cytotoxicity (ADCC) against PD-L1-expressing non-tumor cells. However, natural killer (NK) cells have specific antitumor activity in the presence of tumor-targeting antibody through ADCC, which could enhance NK cell-induced cytotoxicity. We evaluated the antitumor efficacy of ADCC via anti-PD-L1 monoclonal antibodies (mAbs) and NK cells against several PD-L1-positive cancer cell lines.

Methods

Various cancer cell lines were used as target cell lines. Surface PD-L1 expression was analyzed by flow cytometry. IMC-001 and anti-hPD-L1-hIgG1 were tested as anti-PD-L1 mAbs with ADCC and atezolizumab as an anti-PD-L1 mAb without ADCC. NK cell cytotoxicity was measured by ⁵¹Cr-release assay and CD107a degranulation assay. Also, live cell imaging was performed to evaluate cytotoxicity in a single-cell level. NK-92-CD16 (CD16-transduced NK-92 cell line) and peripheral blood mononuclear cells from healthy donors, respectively, were used as an effector cell. FcγRIIIa (CD16a)-V158F genotyping was performed for healthy donors.

Results

We demonstrated that the cytotoxicity of NK-92-CD16 cells toward PD-L1-positive cancer cell lines was significantly enhanced in the presence of anti-PD-L1 mAb with ADCC. We also noted a significant increase in primary human NK cell cytotoxicity against PD-L1-positive human cancer cells when cocultured with anti-PD-L1 mAb with ADCC. Moreover, NK cells expressing a FCGR3A high-affinity genotype displayed higher anti-PD-L1 mAb-mediated ADCC lysis of tumor cells than donors with a low-affinity genotype.

Conclusion

These results suggest that NK cells induce an ADCC response in combination with anti-PD-L1 mAbs, which helps promote ADCC antitumor activity against PD-L1-positive tumors. This study provides support for NK cell immunotherapy against high PD-L1-expressing tumors in combination with ADCC through anti-PD-L1 mAbs.

The landscape of copy number variations in classical Hodgkin lymphoma: a joint KU Leuven and LYSA study on cell-free DNA

The low abundance of Hodgkin/Reed-Sternberg (HRS) cells in lymph node biopsies in classical Hodgkin lymphoma (cHL) complicates the analysis of somatic genetic alterations in HRS cells. As circulating cell-free DNA (cfDNA) contains circulating tumor DNA (ctDNA) from HRS cells, we prospectively collected cfDNA from 177 patients with newly diagnosed, mostly early-stage cHL in a monocentric study at Leuven, Belgium (n = 59) and the multicentric BREACH study by Lymphoma Study Association (n = 118). To catalog the patterns and frequencies of genomic copy number aberrations (CNAs), cfDNA was sequenced at low coverage (0.26×), and data were analyzed with ichorCNA to yield read depth-based copy number profiles and estimated clonal fractions in cfDNA. At diagnosis, the cfDNA concentration, estimated clonal fraction, and ctDNA concentration were significantly higher in cHL cases than controls. More than 90% of patients exhibited CNAs in cfDNA. The most frequent gains encompassed 2p16 (69%), 5p14 (50%), 12q13 (50%), 9p24 (50%), 5q (44%), 17q (43%), 2q (41%). Losses mostly affected 13q (57%), 6q25-q27 (55%), 4q35 (50%), 11q23 (44%), 8p21 (43%). In addition, we identified loss of 3p13-p26 and of 12q21-q24 and gain of 15q21-q26 as novel recurrent CNAs in cHL. At diagnosis, ctDNA concentration was associated with advanced disease, male sex, extensive nodal disease, elevated erythrocyte sedimentation rate, metabolic tumor volume, and HRS cell burden. CNAs and ctDNA rapidly diminished upon treatment initiation, and persistence of CNAs was associated with increased probability of relapse. This study endorses the development of ctDNA as gateway to the HRS genome and substrate for early disease response evaluation.

Current and Future Perspectives of PD-1/PDL-1 Blockade in Cancer Immunotherapy

Cancer immunotherapy, which reactivates weakened immune cells of cancer patients, has yielded great success in recent years. Among immunotherapeutic agents, immune checkpoint inhibitors have been of particular interest and have gained approval by the FDA for treatment of cancers. Immune checkpoint blockade through targeting programmed cell death protein-1 (PD-1) has demonstrated promising antitumor effects in cancer immunotherapy of many different solid and hematologic malignancies. However, despite promising results, a favorable response is observed only in a fraction of patients, and there is still lack of a single therapy modality with curative ability. In this paper, we review the current and future perspectives of PD-1/L1 blockade in cancer immunotherapy, with a particular focus on predictive biomarkers of response to therapy. We also discuss the adverse events associated with PD-1/L1/2 inhibitors, ranging from severe life-threatening conditions such as autoimmune myocarditis to mild and moderate reactions such as skin rashes, and explore the potential strategies for improving the efficacy of immunotherapy with PD-1/L1 checkpoint inhibitors.

Druggable targets meet oncogenic drivers: opportunities and limitations of target-based classification of tumors and the role of Molecular Tumor Boards

The therapeutic landscape of cancer is changing rapidly due to the growing number of approved drugs capable of targeting specific genetic alterations. This aspect, together with the development of noninvasive methods for the assessment of somatic mutations in the peripheral blood of patients, generated a growing interest toward a new tumor-agnostic classification system based on ‘predictive’ biomarkers. The current review article discusses this emerging alternative approach to the classification of cancer and its implications for the selection of treatments. It is suggested that different types of cancers sharing the same molecular profiles could benefit from the same targeted drugs. Although recent clinical trials have demonstrated that this approach cannot be generalized, there are also specific examples that demonstrate the clinical utility of this alternative vision. In this rapidly evolving scenario, a multidisciplinary approach managed by institutional Molecular Tumor Boards is fundamental to interpret the biological and clinical relevance of genetic alterations and the complexity of their relationship with treatment response.

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The identification of oncogenic drivers offers the opportunity to develop target-specific drugs.

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The inhibition of crucial pathways realizes the principle of druggable target to exploit cancer vulnerability.

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The approval of new anticancer agents based on target-based concept represents a paradigm shift in cancer therapy.

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However, only few drugs have been approved so far on an agnostic basis and the concept of biomarker cannot be generalized.

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Tumor Molecular Boards will have an increasing role in the identification of new therapeutic options in selected patients.

Inestabilidad microsatelital y cáncer gástrico

La inestabilidad microsatelital es causada por una alteración de los sistemas de reparación de apareamientoincorrecto, que puede afectar los microsatélites dentro de todo el genoma humano, produciendo errores en su replicación. Los estudios publicados, principalmente en la literatura inglesa, han encontrado que algunos tumores, como los gástricos, pueden expresar inestabilidad microsatelital. En la siguiente revisión de tema, se presenta una descripción de los sistemas de reparación de apareamientos incorrectos y su relación con la presencia de inestabilidad microsatelital en los tumores gástricos, así como su posible utilidad clínica, como factor asociado en la respuesta al tratamiento con inmunoterapia en los pacientes con dicha patología.

Surgery after neoadjuvant immunotherapy in patients with resectable non-small cell lung cancer

Surgery is the standard of care for patients with operable non-small cell lung cancer (NSCLC). However, as a single modality, surgery for early stage or locally advanced NSCLC remains associated with high rates of local and distant recurrence. The addition of neoadjuvant or adjuvant chemotherapy has modestly improved outcomes. While systemic therapy paired with surgery for other malignancies such as breast cancer have resulted in far better outcomes for equivalent stage designations, outcome improvements for operable NSCLC have lagged in part as a result of trials where adjuvant chemotherapy seemed to incur harm for stage IA patients and only modest survival benefit for stage IB–IIIA patients (AJCC 7^th ed.). In recent years, immunotherapy for NSCLC has emerged as a systemic therapy with significant benefit over traditional chemotherapy regimens. These advances with immune checkpoint inhibitors (ICIs) have opened the door to administering peri-operative immunotherapy for operable NSCLC. As a result, a great multitude of studies investigating the use of immunotherapy in combination with surgery for NSCLC as well as several other malignancies have emerged. In this review, we outline the rationale for neoadjuvant immunotherapy in the treatment of operable NSCLC and summarize the available evidence that include preoperative ICI as a single modality or in combination with systemic agents and/or radiotherapy. Further, we summarize how such treatment trajectories open multiple unique windows of opportunity for scientific discovery and potential therapeutic gains for these vulnerable patients.

Predictive value of tumor mutation burden (TMB) with targeted next-generation sequencing in immunocheckpoint inhibitors for non-small cell lung cancer (NSCLC)

Background: To evaluate the clinical predictive value of tumor mutation burden (TMB) for immune checkpoint inhibitor (ICI) therapy in patients with non-small cell lung cancer (NSCLC).

Method: As of 15 February 2020, PubMed, PMC and EMBASE databases as well as the American society of clinical oncology (ASCO) and European society of medical oncology (ESMO) databases were searched. The Mantel-Haenszel or inverse variance weighted fixed-effects model (I² ≤ 50%) or random-effects model (I² > 50%) were used to evaluate OR and its 95% CI of objective response rate (ORR) and disease control rate (DCR) , as well as HR and its 95% CI of progression-free survival (PFS) and overall survival (OS). In addition, we did publication bias, heterogeneity analysis, sensitivity analysis and subgroup analysis. And quality of the studies included and the level of evidence for outcome measures were evaluated.

Results: 14 studies involving 2872 patients were included. The ORR (OR 3.52, 95%CI 2.32-5.35, p < 0.00001), DCR (OR 3.26, 95%CI 1.91-5.55, p < 0.0001), PFS (HR 0.81, 95%CI 0.74-0.89, p < 0.00001) and OS (HR 0.83, 95%CI 0.74-0.94, p = 0.002) of ICI therapy in the high TMB group were all superior to those in the low TMB group.

Conclusions: TMB is a promising biomarker, which can predict the efficacy of ICI therapy in advanced NSCLC patients, included ORR, DCR, PFS and OS.

Extracellular Vesicles and Their Roles in Cancer Progression

Extracellular vesicles (EVs) produced by cancer cells function as a unique form of intercellular communication that can promote cell growth and survival, help shape the tumor microenvironment, and increase invasive and metastatic activity. There are two major classes of EVs, microvesicles (MVs) and exosomes, and they differ in how they are formed. MVs are generated by the outward budding and fission of the plasma membrane. On the other hand, exosomes are derived as multivesicular bodies (MVBs) fuse with the plasma membrane and release their contents. What makes EVs especially interesting is how they mediate their effects. Both MVs and exosomes have been shown to contain a wide-variety of bioactive cargo, including cell surface, cytosolic, and nuclear proteins, as well as RNA transcripts, micro-RNAs (miRNAs), and even fragments of DNA. EVs, and their associated cargo, can be transferred to other cancer cells, as well as to normal cell types, causing the recipient cells to undergo phenotypic changes that promote different aspects of cancer progression. These findings, combined with those demonstrating that the amounts and contents of EVs produced by cancer cells can vary depending on their cell of origin, stage of development, or response to therapies, have raised the exciting possibility that EVs can be used for diagnostic purposes. Moreover, the pharmaceutical community is aggressively pursuing the use of EVs as a potential drug delivery platform. Here, in this chapter, we will highlight what is currently known about how EVs are generated, how they impact cancer progression, and the different ways they are being exploited for clinical applications.

From the T-cell receptor to cancer therapy: an interview with Tak W. Mak

This interview is part of a series of articles to mark the 25th anniversary of the launching of Cell Death and Differentiation.

Identification of an Immune-Related Gene Signature to Improve Prognosis Prediction in Colorectal Cancer Patients

BACKGROUND

Despite recent advance in immune therapy, great heterogeneity exists in the outcomes of colorectal cancer (CRC) patients. In this study, we aimed to analyze the immune-related gene (IRG) expression profiles from three independent public databases and develop an effective signature to forecast patient's prognosis.

METHODS

IRGs were collected from the ImmPort database. The CRC dataset from The Cancer Genome Atlas (TCGA) database was used to identify a prognostic gene signature, which was verified in another two CRC datasets from the Gene Expression Omnibus (GEO). Gene function enrichment analysis was conducted. A prognostic nomogram was built incorporating the IRG signature with clinical risk factors.

RESULTS

The three datasets had 487, 579, and 224 patients, respectively. A prognostic six-gene-signature (CCL22, LIMK1, MAPKAPK3, FLOT1, GPRC5B, and IL20RB) was developed through feature selection that showed good differentiation between the low- and high-risk groups in the training set (p < 0.001), which was later confirmed in the two validation groups (log-rank p < 0.05). The signature outperformed tumor TNM staging for survival prediction. GO and KEGG functional annotation analysis suggested that the signature was significantly enriched in metabolic processes and regulation of immunity (p < 0.05). When combined with clinical risk factors, the model showed robust prediction capability.

CONCLUSION

The immune-related six-gene signature is a reliable prognostic indicator for CRC patients and could provide insight for personalized cancer management.

A Prognostic Model Based on Immune-Related Long Non-Coding RNAs for Patients With Cervical Cancer

Objectives: The study is performed to analyze the relationship between immune-related long non-coding RNAs (lncRNAs) and the prognosis of cervical cancer patients. We constructed a prognostic model and explored the immune characteristics of different risk groups.

Methods: We downloaded the gene expression profiles and clinical data of 227 patients from The Cancer Genome Atlas database and extracted immune-related lncRNAs. Cox regression analysis was used to pick out the predictive lncRNAs. The risk score of each patient was calculated based on the expression level of lncRNAs and regression coefficient (β), and a prognostic model was constructed. The overall survival (OS) of different risk groups was analyzed and compared by the Kaplan–Meier method. To analyze the distribution of immune-related genes in each group, principal component analysis and Gene set enrichment analysis were carried out. Estimation of STromal and Immune cells in MAlignant Tumors using Expression data was performed to explore the immune microenvironment.

Results: Patients were divided into training set and validation set. Five immune-related lncRNAs (H1FX-AS1, AL441992.1, USP30-AS1, AP001527.2, and AL031123.2) were selected for the construction of the prognostic model. Patients in the training set were divided into high-risk group with shorter OS and low-risk group with longer OS (p = 0.004); meanwhile, similar result were found in validation set (p = 0.013), combination set (p < 0.001) and patients with different tumor stages. This model was further confirmed in 56 cervical cancer tissues by Q-PCR. The distribution of immune-related genes was significantly different in each group. In addition, the immune score and the programmed death-ligand 1 expression of the low-risk group was higher.

Conclusions: The prognostic model based on immune-related lncRNAs could predict the prognosis and immune status of cervical cancer patients which is conducive to clinical prognosis judgment and individual treatment.

Cigarette smoke preparations, not electronic nicotine delivery system preparations, induce features of lung disease in a 3D lung repeat-dose model

Cigarette smoking is a risk factor for several lung diseases, including chronic obstructive pulmonary disease, cardiovascular disease, and lung cancer. The potential health effects of chronic use of electronic nicotine delivery systems (ENDS) is unclear. This study utilized fully differentiated primary normal human bronchial epithelial (NHBE) cultures in a repeat-dose exposure to evaluate and compare the effect of combustible cigarette and ENDS preparations. We show that 1-h daily exposure of NHBE cultures over a 10-day period to combustible cigarette whole smoke-conditioned media (WS-CM) increased expression of oxidative stress markers, cell proliferation, airway remodeling, and cellular transformation markers and decreased mucociliary function including ion channel function and airway surface liquid. Conversely, aerosol conditioned media (ACM) from ENDS with similar nicotine concentration (equivalent-nicotine units) as WS-CM and nicotine alone had no effect on those parameters. In conclusion, primary NHBE cultures in a repeat-dose exposure system represent a good model to assess the features of lung disease. This study also reveals that cigarette and ENDS preparations differentially elicit several key endpoints, some of which are potential biomarkers for lung cancer or chronic obstructive pulmonary disease (COPD).

In Cellulo Evaluation of the Therapeutic Potential of NHC Platinum Compounds in Metastatic Cutaneous Melanoma

We describe here the evaluation of the cytotoxic efficacy of two platinum (II) complexes bearing an N-heterocyclic carbene (NHC) ligand, a pyridine ligand and bromide or iodide ligands on a panel of human metastatic cutaneous melanoma cell lines representing different genetic subsets including BRAF-inhibitor-resistant cell lines, namely A375, SK-MEL-28, MeWo, HMCB, A375-R, SK-MEL-5-R and 501MEL-R. Cisplatin and dacarbazine were also studied for comparison purposes. Remarkably, the iodine-labelled Pt-NHC complex strongly inhibited proliferation of all tested melanoma cells after 1-h exposure, likely due to its rapid uptake by melanoma cells. The mechanism of this inhibitory activity involves the formation of DNA double-strand breaks and apoptosis. Considering the intrinsic chemoresistance of metastatic melanoma cells of current systemic treatments, these findings are promising and could give research opportunities in the future to improve the prognosis of patients suffering from unresectable metastatic melanoma that are not eligible or that do not respond to the most effective drugs available to date, namely BRAF inhibitors and the anti-PD-1 monoclonal antibody (mAb).

Clinicopathological associations and prognostic values of IDH1 gene mutation, MGMT gene promoter methylation, and PD-L1 expressions in high-grade glioma treated with standard treatment

INTRODUCTION

the objective was to evaluate the impact of IDH1 R132H mutation, MGMT methylation and PD-L1 expression in high grade glioma that received standard therapy (surgery, radiation and chemotherapy) to overall survival (OS).

METHODS

this is a retrospective study of 35 high grade glioma cases. Genotyping of IDH1 gene alteration on the mutation hotspot R132 (Sanger sequencing method with Applied Biosystems 3500 Genetic Analyzer), EZ DNA Methylation-Gold kit (Zymo Research) is used to study the methylation, Cell line BT549 (ATCC HTB-122) and HCT-116 (ATCC CCL-247) were used as unmethylated control and partially methylated control respectively. Anti-human PD-L1 antibody clone E1L3N®from Cell Signalling Technology (USA) and Rabbit XP®were used to see PDL-1 expression.

RESULTS

anaplastic astrocytoma cases had more MGMT promoter methylation (50%) than glioblastoma multiforme (GBM) (20%), more IDH1 R132H mutation (42%) than GBM (4.3%). Immunohistochemistry tumor proportion score method (TPS) identified 17% and 8.7% were PD-L1 positive in AA and GBM groups, respectively. Cases with IDH1 R132H mutation and MGMT methylation still showed better OS although with high PD-L1 expression.

CONCLUSION

IDH1 R132H mutation and MGMT methylation were good prognostic markers. High expression of PD-L1 apparently might not indicate poor overall survival in the presence of IDH1 R132 mutation and MGMT methylation.

Independent Prognostic Value of Intratumoral Heterogeneity and Immune Response Features by Automated Digital Immunohistochemistry Analysis in Early Hormone Receptor-Positive Breast Carcinoma

Immunohistochemistry (IHC) for ER, PR, HER2, and Ki67 is used to predict outcome and therapy response in breast cancer patients. The current IHC assessment, visual or digital, is based mostly on global biomarker expression levels in the tissue sample. In our study, we explored the prognostic value of digital image analysis of conventional breast cancer IHC biomarkers supplemented with their intratumoral heterogeneity and tissue immune response indicators. Surgically excised tumor samples from 101 female patients with hormone receptor-positive breast cancer (HRBC) were stained for ER, PR, HER2, Ki67, SATB1, CD8, and scanned at 20x. Digital image analysis was performed using the HALO™ platform. Subsequently, hexagonal tiling was used to compute intratumoral heterogeneity indicators for ER, PR and Ki67 expression. Multiple Cox regression analysis revealed three independent predictors of the patient's overall survival: Haralick's texture entropy of PR (HR = 0.19, p = 0.0005), Ki67 Ashman's D bimodality (HR = 3.0, p = 0.01), and CD8+SATB1+ cell density in tumor tissue (HR = 0.32, p = 0.02). Remarkably, the PR and Ki67 intratumoral heterogeneity indicators were prognostically more informative than the rates of their expression. In particular, a distinct non-linear relationship between the rate of PR expression and its intratumoral heterogeneity was observed and revealed a non-linear prognostic effect of PR expression. The independent prognostic significance of CD8+SATB1+ cells infiltrating the tumor could indicate their role in anti-tumor immunity. In conclusion, we suggest that prognostic modeling, based entirely on the computational image-based IHC biomarkers, is possible in HRBC patients. The intratumoral heterogeneity and immune response indicators outperformed both conventional breast cancer IHC and clinicopathological variables while markedly increasing the power of the model.

Immune checkpoint expression, microsatellite instability, and mutational burden: Identifying immune biomarker phenotypes in uterine cancer

OBJECTIVES

Increasing grade of endometrioid endometrial cancer (EEC) is associated with aggressive behavior and poor prognosis. The traditional classification system is limited in its ability to guide treatment planning and prognostication. We identify distinct immune biomarker phenotypes using known markers of immunogenicity to identify patients who may benefit from immune therapy (IT).

METHODS

621 tumors were analyzed by multiplatform profiling. NextGen sequencing was performed on 592 genes. Tumor mutational burden (TMB) was defined as high (H) ≥10mutations/megabase. Microsatellite Instability (MSI) by NGS was ≥46 loci. PD-L1 positivity was ≥2+, >5% by IHC. Chi-square tests were used.

RESULTS

Overall, MSI-H was found in 33% of EECs, most frequent in grade 3 (G3), followed by grade 2 (G2) and grade 1 (G1) tumors (G3: 37%, G2: 32%, G1: 22%, p = 0.007). TMB-H was identified in 25% of EECs. TMB-H was most common in G3, followed by G2 and G1 tumors (G3: 34%, G2: 23%, G1: 13%, p = 0.006). Overall, PD-L1 expression was found in 5.5% of EECs. G3 EECs had the most frequent PD-L1 expression, followed by G2 and G1 tumors (G3: 12%, G2: 3.0%, G1: 0.9%, p < 0.0001). We identified POLE mutations in 4.5% (28/618). All POLE mutated tumors harbored TMB-H phenotypes but MSI-H and PD-L1 were only present in 10.7% and 14.8% of tumors respectively, suggesting upregulation of T-cell immune response in only a fraction of POLE mutated EECs. Triple negative (TN) biomarker phenotype (ER-/PR-/Her2-) was evaluated as a potential surrogate marker of tumor immunogenicity. We identified TN phenotype in 4% of G1 EEC compared with 9% in G2 and 33% in G3, suggesting loss of hormone expression and possible greater immunogenicity with increasing tumor grade.

CONCLUSIONS

High grade tumors appear to be more immunogenic than low grade tumors and may preferentially benefit from IT.

Polyoxidonium® Activates Cytotoxic Lymphocyte Responses Through Dendritic Cell Maturation: Clinical Effects in Breast Cancer

Immunotherapy, which is seen as a major tool for cancer treatment, requires, in some cases, the presence of several agents to maximize its effects. Adjuvants can enhance the effect of other agents. However, despite their long-time use, only a few adjuvants are licensed today, and their use in cancer treatment is rare. Azoximer bromide, marketed under the trade name Polyoxidonium® (PO), is a copolymer of N-oxidized 1,4-ethylenepiperazine and (N-carboxyethyl)-1,4-ethylene piperazinium bromide. It has been described as an immune adjuvant and immunomodulator that is clinically used with excellent tolerance. PO is used in the treatment and prophylaxis of diseases connected with damage to the immune system, and there is interest in testing it in antitumor therapy. We show here that PO treatment for 1 week induced positive pathological changes in 6 out of 20 patients with breast cancer, including complete response in a triple-negative patient. This correlated with an increased tumor CD4⁺ T-lymphocyte infiltration. The immune effects of PO are associated with myeloid cell activation, and little is known about the action of PO on lymphocyte lineages, such as natural killer (NK) and T cells. We reveal that PO increases T-cell proliferation in vitro without negative effects on any activation marker. PO does not affect dendritic cell (DC) viability and increases the expansion of immature DC (iDC) and mature DC (mDC) at 100 μg/ml, and it stimulates expression of several DC co-stimulatory molecules, inducing the proliferation of allogeneic T cells. In contrast, PO decreases DC viability when added at day 5 post-expansion. PO is not toxic for NK cells at doses up to 100 μM and does not affect their activation, maturation, and cytotoxicity but tends to increase degranulation. This could be beneficial against target cells that show low sensitivity to NK cells, e.g., solid tumor cells. Finally, we have found great variability in PO response between donors. In summary, our in vitro results show that PO increases the number of costimulatory molecules on DC that prime T cells, favoring the production of effector T cells. This may support the future clinical development of PO in cancer treatment.

Domatinostat favors the immunotherapy response by modulating the tumor immune microenvironment (TIME)

Background

The efficacy of PD-(L)1 blockade depends on the composition of the tumor immune microenvironment (TIME) and is generally higher in tumors with pre-existing cytotoxic T cells (CTL) than in those with low CTL numbers. Nonetheless, a significant proportion of patients with pre-existing immunity fail to respond, indicating a therapeutic potential for combining PD-(L)1 blockade with additional immunomodulatory agents in both CTL-high and -low immune phenotypes. Here, we evaluated domatinostat (4SC-202), a class I-selective histone deacetylase (HDAC) inhibitor, for its effect on the TIME and its antitumoral efficacy using syngeneic mouse models with CTL-high or CTL-low tumors.

Methods

Domatinostat was evaluated in PD-1 blockade-insensitive CTL-low (CT26) and CTL-high (C38) syngeneic models alone and in combination with different immune-inhibitory and -stimulatory approaches. Effects on the immunophenotype were assessed via flow cytometry and RNA-seq analyses. The changes in RNA-seq-based immune signatures determined in a murine setting were investigated in patient samples from the first-dose cohort of the SENSITIZE trial (NCT03278665) evaluating domatinostat combined with pembrolizumab in advanced-stage melanoma patients refractory/nonresponding to PD-1 blockade.

Results

Domatinostat increased the expression of antigen-presenting machinery (APM) genes and MHC class I and II molecules, along with CTL infiltration, in tumors of both immune phenotypes. In combination with PD-(L)1 blockade, domatinostat augmented antitumor effects substantially above the effects of single-agent therapies, displaying greater benefit in tumors with pre-existing CTLs. In this setting, the combination of domatinostat with agonistic anti-4-1BB or both PD-1 and LAG3 blockade further increased the antitumor efficacy.

In CTL-low tumors, domatinostat enhanced the expression of genes known to reinforce immune responses against tumors. Specifically, domatinostat increased the expression of Ifng and genes associated with responses to pembrolizumab and nivolumab.

Clinically, these findings were confirmed in patients with advanced melanoma treated with domatinostat for 14 days, who demonstrated elevated expression of APM and MHC genes, the IFNG gene, and the IFN-γ and pembrolizumab response signatures in individual tumor samples.

Conclusion

In summary, these data suggest a promising potential of domatinostat in combination with immunotherapy to improve the outcome of refractory cancer patients.

Classical Hodgkin's Lymphoma in the Era of Immune Checkpoint Inhibition

The ligation of programmed cell death 1 (PD-1) with programmed cell death ligand PD-L activates the immune checkpoint leading to T-cell dysfunction, exhaustion, and tolerance, especially in Hodgkin lymphoma (HL) where the PD-L/ Janus kinase (Jak) signaling was frequently found altered. Anti-PD-1 or anti-PD-L1 monoclonal antibodies can reverse this immune checkpoint, releasing the brake on T-cell responses. The characterization of the mechanisms regulating both the expression of PD-1 and PD-L and their function(s) in HL is ongoing. We provide in this review the recent findings focused on this aim with special attention on the major research topics, such as adverse events and resistance to PD-1–PD-L1 inhibitor treatment, together with a part about angiogenesis, extracellular vesicles, and microbiome in HL pathogenesis.

Different Expression Characteristics of LAG3 and PD-1 in Sepsis and Their Synergistic Effect on T Cell Exhaustion: A New Strategy for Immune Checkpoint Blockade

The impairment of immunity characterized by T cell exhaustion is the main cause of death in patients with sepsis after the acute phase. Although PD-1 blockade is highly touted as a promising treatment for improving prognosis, the role of PD-1 plays in sepsis and particularly its different roles in different periods are still very limited. A recent study revealed LAG3 can resist the therapeutic effect of PD-1 blockade in tumor, which inspired us to understand their role in sepsis. We enrolled 26 patients with acute sepsis from 422 candidates using strict inclusion criteria. Follow-up analysis revealed that the expression levels of PD-1 were rapidly increased in the early stage of sepsis but did not change significantly as infection continued (P < 0.05). However, the expression of LAG3 was contrary to that of PD-1. Compared with LAG3 or PD-1 single-positive T cells, T cells coexpressing LAG3 and PD-1 were significantly exhausted (P < 0.05). The proportion of coexpressing T cells was negatively correlated with the total number of lymphocytes (r = −0.653, P = 0.0003) and positively correlated with the SOFA score (r = 0.712, P < 0.0001). In addition, the higher the proportion of coexpressing T cells was, the longer the hospital stay and the higher the mortality. These results showed that LAG3 and PD-1 had a potential synergistic effect in regulating the gradual exhaustion of T cells in sepsis, which seriously affected the clinical prognosis of patients. Therefore, LAG3 and PD-1 double-positive T cells are an important indicator for immunity detection and prognostic evaluation. In the future, precision therapy may pay more attention to the different expression patterns of these two molecules.

PD-L1/PD-1 Expression in Endometrial Clear Cell Carcinoma: A Potential Surrogate Marker for Clinical Trials

Background. Endometrial clear cell carcinoma (ECCC) represents a rare subtype of endometrial cancer. Recently, immunotherapeutic drugs targeting programmed cell death protein 1 (PD-1)/programmed death ligand-1 (PD-L1) was associated with improved survival in several types of cancer (especially in patients with mismatch-repair (MMR)-deficient status). The aim of this study is to evaluate the correlation between the PD-L1/PD-1 axis and clinical and pathological features in strictly defined ECCC diagnosed at our institution. Design. Review of ECCC (diagnosed in the period of 2000 to 2017) identified 23 cases (n = 23) in our institution. The cases were reviewed by 2 gynecological pathologists. Estrogen receptor, progesterone receptor, napsin A, p16, and p53 were also performed so that only pure CCC cases were included. PD-L1 (SP142), PD-1, and MMR antibodies were performed. PD-L1 and PD-1 were scored in both the tumor and the peritumoral lymphocyte infiltration. Clinical and pathological features were recorded to correlate with the expression of the 2 markers. Results. Among the 23 cases, 20 cases were qualified for pure CCC by histology and immunohistochemistry patterns. Regarding PD-1 expression, 6/20 (30%) patients had positive expression in peritumoral lymphocyte infiltration. While 3/20 (15%) cases had PD-L1 either tumoral or peritumoral lymphocytes expression. Loss of MMR expression was present in 1 (5%) of 20 patients. PD-1 and/or PD-L1 expression cases tended to have deeper myometrial invasion and higher stage at presentation. Conclusions. Our results are suggestive of the roles of both PD-1 and PD-L1 in ECCCs as useful therapeutic biomarkers for immunotherapy.

Biomarkers for Predicting Response to Immunotherapy with Immune Checkpoint Inhibitors in Cancer Patients

BACKGROUND

Immunotherapy, especially the use of immune checkpoint inhibitors, has revolutionized the management of several different cancer types in recent years. However, for most types of cancer, only a minority of patients experience a durable response. Furthermore, administration of immunotherapy can result in serious adverse reactions. Thus, for the most efficient and effective use of immunotherapy, accurate predictive biomarkers that have undergone analytical and clinical validation are necessary.

CONTENT

Among the most widely investigated predictive biomarkers for immunotherapy are programmed death-ligand 1 (PD-L1), microsatellite instability/defective mismatch repair (MSI/dMMR), and tumor mutational burden (TMB). MSI/dMMR is approved for clinical use irrespective of the tumor type, whereas PD-L1 is approved only for use in certain cancer types (e.g., for predicting response to first-line pembrolizumab monotherapy in non-small cell lung cancer). Although not yet approved for clinical use, TMB has been shown to predict response to several different forms of immunotherapy and across multiple cancer types. Less widely investigated predictive biomarkers for immunotherapy include tumor-infiltrating CD8⁺ lymphocytes and specific gene signatures. Despite being widely investigated, assays for MSI/dMMR, PD-L1, and TMB lack standardization and are still evolving. An urgent focus of future research should be the optimization and standardization of method for determining these biomarkers.

SUMMARY

Biomarkers for predicting response to immunotherapy are paving the way for personalized treatment for patients with diverse cancer types. However, standardization of the available biomarker assays is an urgent requirement.

Role of tumor gene mutations in treatment response to immune checkpoint blockades

Early studies shed light on the immune suppression of immune checkpoint molecules in the cancer microenvironment, with later studies applying immune checkpoint blockade (ICB) in treatment of various malignancies. Despite the encouraging efficacy of ICBs in a substantial subset of cancer patients, the treatment response varies. Gene mutations of both tumor cells and immune cells in the tumor microenvironment have recently been identified as potential predictors of the ICB response. Recent developments in gene expression profiling of tumors have allowed identification of a panel of mutated genes that may affect tumor cell response to ICB treatment. In this review, we discuss the association of the ICB response with gene expression and mutation profiles in tumor cells, which it is hoped will help to optimize the clinical application of ICBs in cancer patients.

Liquid biopsy for lung cancer immunotherapy

The recent successful use of the immune checkpoint inhibitors (CPIs) anti-programmed death receptor-1 (PD-1)/PD-1 ligand 1 in clinical trials indicates their crucial role in obtaining an effective cancer immune therapy. These CPIs have been identified to have an effective therapeutic response, particularly in tumors with high tumor mutation burden. Targeting private somatic mutations encoding immunogenic neoantigens (neo-Ags) has been developed as an autologous gene therapy. T-cell receptor-engineered T cells targeting neo-Ags are a novel option for adoptive cell therapy used for the treatment of lung cancer. However, not all patients experience an effective response from immunotherapy. Although the resistance mechanism of CPIs has been reported, its association with other treatment methods during systemic anticancer therapy remains unclear, particularly the treatment options following the emergence of drug resistance in lung cancer. The potential biomarkers used for liquid biopsy may assist in the identification of patients who would benefit the most from immunotherapy. Attempts to identify potential biomarkers for predicting clinical response to immunotherapy are underway. With regard to liquid biopsy, the present review summarizes and discusses the lung cancer management of immunotherapy for precision medicine by reviewing recent literature and associated clinical trials.