Programmed Death 1/programmed Death Ligand 1 Research Articles

Beta cell extracellular vesicle PD-L1 as a novel regulator of CD8+ T cell activity and biomarker during the evolution of Type 1 Diabetes.

Surviving beta cells in type 1 diabetes respond to inflammation by upregulating programmed death-ligand 1 (PD-L1) to engage immune cell programmed death-1 (PD-1) and limit destruction by self-reactive immune cells. Extracellular vesicles (EVs) and their cargo can serve as biomarkers of beta cell health and contribute to islet intercellular communication. We hypothesized that the inflammatory milieu of type 1 diabetes increases PD-L1 in beta cell EV cargo and that EV PD-L1 may protect beta cells against immune-mediated cell death. Beta cell lines and human islets were treated with proinflammatory cytokines to model the proinflammatory type 1 diabetes microenvironment. EVs were isolated using ultracentrifugation or size exclusion chromatography and analysed via immunoblot, flow cytometry, and ELISA. EV PD-L1: PD-1 binding was assessed using a competitive binding assay and in vitro functional assays testing the ability of EV PD-L1 to inhibit NOD CD8 T cells. Plasma EV and soluble PD-L1 were assayed in plasma of individuals with islet autoantibody positivity (Ab+) or recent-onset type 1 diabetes and compared to non-diabetic controls. PD-L1 protein colocalized with tetraspanin-associated proteins intracellularly and was detected on the surface of beta cell EVs. 24-h IFN-α or IFN-γ treatment induced a two-fold increase in EV PD-L1 cargo without a corresponding increase in number of EVs. IFN exposure predominantly increased PD-L1 expression on the surface of beta cell EVs and beta cell EV PD-L1 showed a dose-dependent capacity to bind PD-1. Functional experiments demonstrated specific effects of beta cell EV PD-L1 to suppress proliferation and cytotoxicity of murine CD8 T cells. Plasma EV PD-L1 levels were increased in islet Ab+ individuals, particularly in those with single Ab+, Additionally, in from individuals with either Ab+ or type 1 diabetes, but not in controls, plasma EV PD-L1 positively correlated with circulating C-peptide, suggesting that higher EV-PD-L1 could be protective for residual beta cell function. IFN exposure increases PD-L1 on the beta cell EV surface. Beta cell EV PD-L1 binds PD1 and inhibits CD8 T cell proliferation and cytotoxicity. Circulating EV PD-L1 is higher in islet autoantibody positive patients compared to controls. Circulating EV PD-L1 levels correlate with residual C-peptide at different stages in type 1 diabetes progression. These findings suggest that EV PD-L1 could contribute to heterogeneity in type 1 diabetes progression and residual beta cell function and raise the possibility that EV PD-L1 could be exploited as a means to inhibit immune-mediated beta cell death.

Immunotherapy Based on Immune Checkpoint Molecules and Immune Checkpoint Inhibitors in Gastric Cancer-Narrative Review.

Due to its rapid progression to advanced stages and highly metastatic properties, gastric cancer (GC) is one of the most aggressive malignancies and the fourth leading cause of cancer-related deaths worldwide. The metastatic process includes local invasion, metastasis initiation, migration with colonisation at distant sites, and evasion of the immune response. Tumour growth involves the activation of inhibitory signals associated with the immune response, also known as immune checkpoints, including PD-1/PD-L1 (programmed death 1/programmed death ligand 1), CTLA-4 (cytotoxic T cell antigen 4), TIGIT (T cell immunoreceptor with Ig and ITIM domains), and others. Immune checkpoint molecules (ICPMs) are proteins that modulate the innate and adaptive immune responses. While their expression is prominent on immune cells, mainly antigen-presenting cells (APC) and other types of cells, they are also expressed on tumour cells. The engagement of the receptor by the ligand is crucial for inhibiting or stimulating the immune cell, which is an extremely important aspect of cancer immunotherapy. This narrative review explores immunotherapy, focusing on ICPMs and immune checkpoint inhibitors in GC. We also summarise the current clinical trials that are evaluating ICPMs as a target for GC treatment.

Antibody-Drug Conjugates as Novel Therapeutic Agents for Non-Small Cell Lung Carcinoma with or without Alterations in Oncogenic Drivers.

Antibody-drug conjugates (ADCs) are an emerging class of therapeutics for lung cancer, and several are currently in development for this malignancy. The structure of these molecules is based on an antibody that targets a protein on the lung cancer cell surface and a cytotoxic payload attached by a linker. Many protein targets, including TROP2, c-MET, CEACAM5, HER2, and HER3 have been identified. In metastatic non-small cell lung carcinoma (NSCLC) without alterations in oncogenic drivers, platinum-based chemotherapy and immune checkpoint inhibitors (ICIs) targeting the programmed death-1/programmed death-ligand 1 (PD1/PDL1) interaction are the standard first-line treatments. In patients with EGFR-mutated or ALK-rearranged NSCLC, tyrosine kinase inhibitors (TKIs) are recommended. However, although the prognosis of patients with metastatic NSCLC differs between such with and without alterations in oncogenic drivers, most patients eventually experience disease progression. A novel therapeutic class is needed in routine practice to overcome the mechanisms of resistance to ICIs and EGFR/ALK TKIs. Several ADCs have already been approved for other cancers, such as breast cancer and urothelial carcinoma. This review summarizes the knowledge about the efficacy and tolerance profiles of ADCs targeting TROP2, HER2, HER3, CEACAM5 and c-MET in metastatic NSCLC with and without alterations in oncogenic drivers.

Abstract 7528: Coordinated regulation of critical immune checkpoint proteins by the integrated stress response (ISR) pathway in lung cancer

Abstract Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related deaths worldwide. Despite recent advances, high rates of recurrence highlight the need for novel treatment options. Groundbreaking discoveries in identifying and exploiting the PD-1/PD-L1 (Programmed Death 1/Programmed Death Ligand 1) immune checkpoint have resulted in the approval of monoclonal antibodies that disrupt this interaction as a first-line therapy for lung cancer patients. However, only ~20% of NSCLC patients benefit from checkpoint blockade. A critical question remains as to what mechanisms facilitate resistance to PD-1/PD-L1 therapy and whether other immune checkpoints or pathways can be pursued clinically in combination with this therapy. The integrated stress response (ISR) pathway represents an emerging therapeutic vulnerability. The ISR is a generalized response to maintain cellular homeostasis, and is known to be activated by hypoxia, heme deprivation, amino acid starvation, and oncogenic activation. We previously demonstrated that ISR activation potently induces PD-L1 in NSCLC and suppression of anti-tumor immunity (Suresh et al, Nature Cancer, 2020). We discovered that ISR pathway activation enhances PD-L1 translation through the bypass of inhibitory upstream open reading frames (uORFs) in the PD-L1 5' UTR and a mechanistic link to the translation initiation factor eIF5B. Our latest studies demonstrate that the immune checkpoint protein, CD155 (Cluster of Differentiation 155), is induced by ISR activation. We find that both PD-L1 and CD155 are induced by multiple arms of the ISR pathway, and CD155 harbors inhibitory uORFs in its 5' UTR. Importantly, we observed a significant correlation between PD-L1 and CD155 expression in a panel of primary human lung adenocarcinomas. We further demonstrated that ISR activation inhibits T cell function in vitro and promotes tumor growth in the CMT167 syngeneic mouse model. Analysis of immune cell infiltration using mass cytometry in this in vivo model is ongoing. Currently, we are determining the extent to which ISR inhibition suppresses tumorigenesis by promoting anti-tumor immunity and whether this may synergize with existing immune checkpoint therapies. Overall, these studies will set the stage for determining whether inhibition of the ISR pathway alone or in combination with immune checkpoint blockade will benefit lung cancer patients. Our studies may also lead to new therapeutic approaches to trigger anti-cancer immune responses and improve current strategies. Citation Format: Shayna Elizabeth Thomas-Jardin, Shruthy Suresh, Cheryl Lewis, Chul Ahn, Bret M. Evers, John D. Minna, Kathryn A. O'Donnell. Coordinated regulation of critical immune checkpoint proteins by the integrated stress response (ISR) pathway in lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7528.

Assessment of programmed cell death ligand- 1 (PD-L1) expression in oral potentially malignant disorders and oral squamous cell carcinoma - An immunohistochemical study

OSCC is multifactorial and is a multistep process. It may arise de-novo or may be preceded by oral potentially malignant disorders(OPMD). During malignant transformation certain molecular changes are evident at cellular level even in the absence of phenotypic changes in the tissue. With the recent advances in molecular understanding of cancers, immune checkpoint inhibitors have been recognized as perpetrators or supporters in the pathophysiology of various cancers. One of the main immunosuppressive pathways is the programmed death 1 (PD-1)/programmed death-ligand 1 (PD-L1) in which there is an interaction between T-cell PD-1 receptor and PD-L1 on cancer cells. Upregulation of PD-L1 is associated with disease progression.To assess and compare the PD-L1 expression in OPMD and OSCC.64 Paraffin embedded tissue sections of histopathologically diagnosed cases of 32 OSCC and 32 OPMD were immunohistochemically stained with PD-L1 & its membranous expression was evaluated. Descriptive statistical analysis was applied.Thus the study showed 100 % PD-L1 positive expression in OSCC and PD-L1 expression increased with increase in histopathological. In case of OPMD 93.74 % showed positive PD-L1 expression. We found PDL1 expression is significantly higher in OSCC (Mean= 4.59 ± 1.965) compared to OPMD (Mean= 2.03 ± 1.204).Assessment of PD-L1 expression in OPMD patients will help us to screen the subjects with or without risk of malignant transformation as increase in PD-L1 expression signifies the increased risk of malignant change.

Expert consensus on PD-L1 expression testing in esophageal carcinoma in China

In recent years, immunotherapy represented by immune checkpoint inhibitors programmed death 1 (PD-1) has made great progress in the treatment of esophageal cancer and is rewriting the global paradigm for the treatment of esophageal cancer. According to current data, only a small number of patients with esophageal cancer could benefit from immunotherapy. Therefore, it is a challenge to screen the potential beneficiaries of PD-1 inhibitors. Studies have shown that the expression level of programmed death-ligand 1 (PD-L1) in esophageal cancer is closely associated with the efficacy of PD-1 inhibitors, and PD-L1 is the most important predictive biomarker of the efficacy of PD-1 inhibitors. With the clinical application of different PD-1 inhibitors and PD-L1 protein expression detection platforms, clarifying the clinical significance and timing of detection of PD-L1 protein expression in esophageal cancer, and establishing a standardized PD-L1 testing procedure, are of great significance to improve the accuracy of detection and reduce the difference between laboratories, so as to maximize the therapeutic benefits for patients. This consensus was finally reached, based on the combination of literature, expert experience, and internal discussion and voting of committee members, to provide an accurate and reliable evidence for clinicians to make decisions.

The genetic influence of PD-1/PD-L1 axis single nucleotide polymorphisms on the incidence of type 1 diabetes mellitus in pediatric Egyptian patients

BackgroundThe increasing prevalence of diabetes mellitus (DM) is one of the most challenging public health issues. The destruction of insulin-producing cells in the islets of Langerhans is the hallmark of type 1 diabetes mellitus (T1DM) as an autoimmune disease. In the current case–control study, the role of single nucleotide polymorphisms (SNPs) was investigated within the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) inhibitory axis and their association with T1DM susceptibility in a sample of Egyptian pediatric patients. The study included 80 T1DM pediatric patients and 76 healthy control subjects. The patients were recruited from Beni-Suef University Hospital’s Pediatric Endocrinology Outpatient Clinic. Genotyping of PD-1 SNP (rs 34819629) and PD-L1 SNPs (rs 2297137 and rs 4143815) was performed by TaqMan allelic discrimination technique via real-time polymerase chain reaction (RT-PCR). The patients were subjected to a thorough clinical examination and history taking.ResultGenotyping of PD-1 (rs 34819629) revealed that all of the enrolled patients and the control group inherited the same genotype (GG genotype). With regard to PDL-1 rs4143815 SNP and the risk of T1DM occurrence, our comparison did not reveal the presence of an association between the different genetic models (general, dominant, and recessive) of the SNP and the risk of T1DM (p = 0.078 and p = 0.055; for the general genetic model, p = 0.061 and p = 0.169 for the dominant and the recessive types, respectively). Regarding PDL-1 rs2297137 SNP, the results of this study demonstrated that the risk of T1DM was significantly associated with the recessive genetic model (p = 0.007) as the diabetic group’s predominant G allele was higher compared to the control group.ConclusionThe findings obtained supported the hypothesis that the predominant G allele of PD-L1 rs2297137 is associated with the development of T1DM. Chronic hyperglycemia and long-standing diabetes problems are linked to both PD-L1 SNPs (rs4143815 and rs2297137). Future studies with a more significant number of patients are required to support our results.

Computational Investigations on the Natural Small Molecule as an Inhibitor of Programmed Death Ligand 1 for Cancer Immunotherapy.

Several therapeutic monoclonal antibodies approved by the FDA are available against the PD-1/PD-L1 (programmed death 1/programmed death ligand 1) immune checkpoint axis, which has been an unprecedented success in cancer treatment. However, existing therapeutics against PD-L1, including small molecule inhibitors, have certain drawbacks such as high cost and drug resistance that challenge the currently available anti-PD-L1 therapy. Therefore, this study presents the screening of 32,552 compounds from the Natural Product Atlas database against PD-L1, including three steps of structure-based virtual screening followed by binding free energy to refine the ideal conformation of potent PD-L1 inhibitors. Subsequently, five natural compounds, i.e., Neoenactin B1, Actinofuranone I, Cosmosporin, Ganocapenoid A, and 3-[3-hydroxy-4-(3-methylbut-2-enyl)phenyl]-5-(4-hydroxybenzyl)-4-methyldihydrofuran-2(3H)-one, were collected based on the ADMET (absorption, distribution, metabolism, excretion, and toxicity) profiling and binding free energy (>−60 kcal/mol) for further computational investigation in comparison to co-crystallized ligand, i.e., JQT inhibitor. Based on interaction mapping, explicit 100 ns molecular dynamics simulation, and end-point binding free energy calculations, the selected natural compounds were marked for substantial stability with PD-L1 via intermolecular interactions (hydrogen and hydrophobic) with essential residues in comparison to the JQT inhibitor. Collectively, the calculated results advocate the selected natural compounds as the putative potent inhibitors of PD-L1 and, therefore, can be considered for further development of PD-L1 immune checkpoint inhibitors in cancer immunotherapy.

Measurement of soluble PD-1 and soluble PD-L1 as well as PD-L1 and PD-1 from perioperative patients with gastric carcinoma.

Till now, no experiment has been performed to detect programmed death ligand 1 (PD-L1)/programmed death 1 (PD-1), soluble PD-L1/soluble PD-1 simultaneously in perioperative patients of gastric carcinoma. Our experiment aims at determining the clinical significance and possible mechanism of soluble PD-L1/soluble PD-1 in gastric carcinoma. Thirty patients undergone gastrectomy were selected as the experimental group. Tissue's programmed death ligand 1 and peripheral programmed death 1 were detected using immunofluorescence and flow cytometry. Soluble PD-L1 and soluble PD-1 were detected using enzyme-linked immunosorbent assay. First, preoperative programmed death 1 was higher than control group and decreased to normal post-operatively. Preoperatively ,elevated levels of programmed death 1 on cluster of differentiation (CD)4 T cells indicated less lymphatic metastasis (P<0.01) and small tumor volume (P<0.01); elevated programmed death 1 of CD8 T cells indicated big tumor volume (P<0.01) and well histological differentiation (P<0.01). Second, preoperative soluble PD-L1 and soluble PD-1 are lower than in control group. Post-operatively, the soluble PD-1 rose to normal, but the soluble PD-L1 showed no change. Third, programmed death ligand 1 can be observed in carcinoma tissue. Fourth, the area under the curve of soluble PD-1 (0.675) for diagnosis was worse than that of soluble PD-L1 (0.885). Kaplan-Meier analysis showed that soluble PD-1<245.26pg/ml in post-operative serum predicted a poor prognosis (overall survival percentage: 60%) at 2 years (P<0.05). Multivariate analysis revealed that carcinoembryonic antigen (>5ng/l) and soluble PD-1 after gastrectomy (>245.26pg/ml) were independent prognostic factors for overall survival (hazard ratio: 20.812, 95% confidence interval: 1.217-355.916, P=0.036; hazard ratio: 0.028, 95% confidence interval: 0.001-0.786, P=0.036, respectively). We propose that soluble PD-1 combined with programmed death ligand 1 are effective not only in protecting T cells from the adhesion by programmed death ligand 1 but also in preventing the occurrence and the development of tumor as well. Through multivariate analysis, we found that soluble PD-1 was an independent protective factor for post-operative prognosis of gastric carcinoma patients, which indirectly verified the vital function of soluble PD-1. Soluble PD-1 might be promising predictive biomarkers for the diagnosis and prognosis of gastric carcinoma patients.

Transarterial chemoembolisation enhances programmed death-1 and programmed death-ligand 1 expression in hepatocellular carcinoma.

Immunotherapies represent a new alternative therapeutic approach for hepatocellular carcinomas (HCCs), and have shown promising results when used in combination therapy. The aim of this study was to evaluate the potential of transarterial chemoembolisation (TACE) to modulate programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) expression profiles in a cohort of surgically treated HCCs. A total of 82 surgically treated HCCs from patients who had undergone (n=32) or not undergone (n=50) preoperative TACE were included in the study. Immunohistochemical expression of PD-1 and of PD-L1 were analysed and compared according to TACE treatment. Pretreatment biopsies, which were available for 30 cases (20 with TACE and 10 without), were similarly analysed. Follow-up data were retrieved from patients' charts. PD-1 expression (≥1%) in intratumoral inflammatory cells (ICs) was observed in 46% of HCCs, and PD-L1 expression (≥1%) in ICs and PD-L1 expression in tumour cells (TCs) were observed in 46% and 16% of HCCs, respectively. A low level of PD-1 expression (<1%) was associated with strong and diffuse glutamine synthetase overexpression (8% versus 27%, P=0.024). HCCs from patients with TACE pretreatment showed significantly higher PD-L1 expression in TCs than those from patients without TACE pretreatment (2% versus 0.4%, P=0.027). PD-1 expression in ICs and PD-L1 expression in both ICs and TCs were higher in TACE-resected tumours than in corresponding pre-TACE biopsies (respectively: 1.8% versus 8.1%, P=0.034; 0.8% versus 7.1%, P=0.032; and 0% versus 2.4%, P=0.043). Our results, showing increases in PD-1 expression and PD-L1 expression in HCCs following TACE, support the use of TACE in combination with immunotherapy in selected cases to optimise tumour response.

Cutaneous immune-related adverse events in patients with melanoma treated with checkpoint inhibitors.

Checkpoint inhibitor (CPI) therapy has vastly improved long-term outcomes in metastatic malignant melanoma (MMM). Therapy takes the form of monoclonal antibody infusions that target immune cell checkpoint proteins, such as cytotoxic T-lymphocyte-associated protein 4 (CTLA4) and programmed death 1/programmed death ligand 1 (PD1/PDL1). Cutaneous immune-related adverse effects (IrAEs) are frequent in patients with MMM treated with CPIs. Our aim was to review the clinical presentations of cutaneous IrAEs associated with CPI therapy in adult patients with MMM. We carried out a literature review of clinical trials, case series and case reports of patients with melanoma and those with other cancers treated with anti-CTLA4, anti-PD1/PDL1, or a combination of these therapies. Diverse clinical presentations of cutaneous IrAEs are recognized. Anti-CTLA4 therapy has a higher associated rate of cutaneous IrAEs than anti-PD1/PDL1 therapies. Low-grade cutaneous IrAEs are common and are usually managed supportively while continuing CPI therapy. Delayed presentations arising after established use of CPIs can make therapy-associated cutaneous IrAEs difficult to distinguish from coincidental dermatological disease. Vitiligo-like depigmentation is a good prognostic indicator of outcome in patients with melanoma. Life-threatening adverse events including toxic epidermal necrolysis are rare. The identification of predictive biomarkers that highlight patients at risk of life-threatening IrAEs remains an unmet need. The involvement of dermatologists in the multidisciplinary assessment of cutaneous IrAEs is increasingly pertinent in the management and care of CPI-treated patients with melanoma.

Microenvironment Remodeling and Subsequent Clinical Implications in Diffuse Large B-Cell Histologic Variant of Richter Syndrome.

IntroductionRichter Syndrome (RS) is defined as the development of an aggressive lymphoma in the context of Chronic Lymphocytic Leukemia (CLL), with a Diffuse Large B-Cell Lymphoma (DLBCL) histology in 95% cases. RS genomic landscape shares only a few features with de novo DLBCLs and is marked by a wide spectrum of cytogenetic abnormalities. Little is known about RS microenvironment. Therapeutic options and efficacy are limited, leading to a 12 months median overall survival. The new targeted treatments usually effective in CLL fail to obtain long-term remissions in RS.MethodsWe reviewed available PubMed literature about RS genomics, PD-1/PD-L1 (Programmed Death 1/Programmed Death Ligand 1) pathway triggering and subsequent new therapeutic options.ResultsData from about 207 patients from four landmark papers were compiled to build an overview of RS genomic lesions and point mutations. A number of these abnormalities may be involved in tumor microenvironment reshaping. T lymphocyte exhaustion through PD-L1 overexpression by tumor cells and subsequent PD-1/PD-L1 pathway triggering is frequently reported in solid cancers. This immune checkpoint inhibitor is also described in B lymphoid malignancies, particularly CLL: PD-1 expression is reported in a subset of prolymphocytes from the CLL lymph node proliferation centers. However, there is only few data about PD-1/PD-L1 pathway in RS. In RS, PD-1 expression is a hallmark of recently described « Regulatory B-cells », which interact with tumor microenvironment by producing inhibiting cytokines such as TGF-β and IL-10, impairing T lymphocytes anti-tumoral function. Based upon the discovery of high PD-1 expression on tumoral B lymphocyte from RS, immune checkpoint blockade therapies such as anti-PD-1 antibodies have been tested on small RS cohorts and provided heterogeneous but encouraging results.ConclusionRS genetic landscape and immune evasion mechanisms are being progressively unraveled. New protocols using targeted treatments such as checkpoint inhibitors as single agents or in combination with immunochemotherapy are currently being evaluated.

Incidence and Risk of Colitis With Programmed Death 1 Versus Programmed Death Ligand 1 Inhibitors for the Treatment of Cancer

Colitis is a major immune-related adverse event associated with programmed death 1 (PD-1) and programmed death-ligand 1 (PD-L1) inhibitors, but the risk of colitis with PD-1 versus PD-L1 inhibitors is not well characterized. We performed a meta-analysis for the incidence of all grade and grade 3-4 colitis with PD-1 inhibitor (nivolumab, pembrolizumab, and cemiplimab) or PD-L1 inhibitor (atezolizumab, avelumab, and durvalumab) monotherapy using a fixed effects model. We also conducted subgroup meta-analyses of non-small cell lung cancer (NSCLC) or urothelial carcinoma (UC) trials, and a network meta-analysis of randomized trials comparing PD-1 or PD-L1 inhibitors with docetaxel for NSCLC. We also analyzed the Food and Drug Administration Adverse Event Reporting System database to estimate the reporting odds ratio of each medication. PD-1 inhibitors were associated with a higher incidence of all grade and grade 3-4 colitis compared with PD-L1 inhibitors in the analysis of all cancer types [1.49% vs. 0.83%, relative risk; 1.80, 95% confidence interval (CI); 1.22-2.67 for all grade colitis, and 0.85% vs. 0.34%, relative risk; 2.52, 95% CI; 1.46-4.37 for grade 3-4 colitis]. The meta-analyses of NSCLC and UC trials, and the network meta-analysis of NSCLC trials were also suggestive of a higher risk of colitis with PD-1 versus PD-L1 inhibitors. The reporting odds ratio of colitis with PD-1 versus PD-L1 inhibitors was 1.80 (95% CI; 1.53-2.14). In this meta-analysis of clinical trials exploring PD-1 and PD-L1 inhibitors in solid tumors, PD-1 inhibitors were associated with a higher risk of colitis.

Incidence and risk of colitis with programmed death-1 versus programmed death-ligand 1 inhibitors for the treatment of cancer.

e15087 Background: Programmed death 1 (PD-1) inhibitors and Programmed Death-Ligand 1 (PD-L1) inhibitors are immune checkpoint inhibitors (ICIs) approved for treatment of several different cancers. Colitis is a major immune-related adverse event associated with ICIs, but the risk of colitis with PD-1 versus PD-L1 inhibitors is not well characterized. Methods: We performed a meta-analysis for the incidence of all grade and grade 3-4 colitis with PD-1 inhibitor (nivolumab, pembrolizumab, and cemiplimab) or PD-L1 inhibitor (atezolizumab, avelumab, and durvalumab) monotherapy using a fixed effects model. We also conducted subgroup meta-analyses of non-small cell lung cancer (NSCLC) or urothelial carcinoma (UC) trials, and a network meta-analysis of randomized trials comparing PD-1 or PD-L1 inhibitors with docetaxel for NSCLC. We analyzed Food and Drug Administration Adverse Event Reporting System (FAERS) database to estimate the reporting odds ratio (ROR) of each medication, which provides the estimated relative risk most valid in spontaneous report database. Results: We identified 88 studies that met inclusion for the analysis. PD-1 inhibitors were associated with higher incidence of all grade and grade 3-4 colitis compared to PD-L1 inhibitors in the analysis of all cancer types (1.49% vs 0.83%, relative risk (RR); 1.80, 95% confidence interval (CI); 1.22-2.67 for all grade colitis, and 0.85% vs 0.34%, RR; 2.52, 95% CI; 1.46-4.37 for grade 3-4 colitis). The meta-analyses on NSCLC and UC, and the network meta-analysis on NSCLC also showed the tendency that PD-1 inhibitors are associated with higher risk of all grade and grade 3-4 colitis, though only the analysis on UC for all grade colitis showed a significant difference. (1.95% vs 0.64%, RR; 3.05, 95% CI; 1.18 - 7.88) Retrospective analysis showed ROR of 16.78 (95% CI; 15.8-17.8) for PD-1 inhibitors, and 12.93 (95% CI; 10.74-15.42) for PD-L1 inhibitors. We found that ROR of PD-1inhibitors was 1.17 (95% CI; 0.97-1.43) compared to PD-L1 inhibitors. Conclusions: Our study showed that PD-1 inhibitors have higher risk of colitis than PD-L1 inhibitors.

Review of Indications of FDA-Approved Immune Checkpoint Inhibitors per NCCN Guidelines with the Level of Evidence.

Cancer is associated with higher morbidity and mortality and is the second leading cause of death in the US. Further, in some nations, cancer has overtaken heart disease as the leading cause of mortality. Identification of molecular mechanisms by which cancerous cells evade T cell-mediated cytotoxic damage has led to the modern era of immunotherapy in cancer treatment. Agents that release these immune brakes have shown activity to recover dysfunctional T cells and regress various cancer. Both cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) and Programmed Death-1 (PD-1) play their role as physiologic brakes on unrestrained cytotoxic T effector function. CTLA-4 (CD 152) is a B7/CD28 family; it mediates immunosuppression by indirectly diminishing signaling through the co-stimulatory receptor CD28. Ipilimumab is the first and only FDA-approved CTLA-4 inhibitor; PD-1 is an inhibitory transmembrane protein expressed on T cells, B cells, Natural Killer cells (NKs), and Myeloid-Derived Suppressor Cells (MDSCs). Programmed Death-Ligand 1 (PD-L1) is expressed on the surface of multiple tissue types, including many tumor cells and hematopoietic cells. PD-L2 is more restricted to hematopoietic cells. Blockade of the PD-1 /PDL-1 pathway can enhance anti-tumor T cell reactivity and promotes immune control over the cancerous cells. Since the FDA approval of ipilimumab (human IgG1 k anti-CTLA-4 monoclonal antibody) in 2011, six more immune checkpoint inhibitors (ICIs) have been approved for cancer therapy. PD-1 inhibitors nivolumab, pembrolizumab, cemiplimab and PD-L1 inhibitors atezolizumab, avelumab, and durvalumab are in the current list of the approved agents in addition to ipilimumab. In this review paper, we discuss the role of each immune checkpoint inhibitor (ICI), the landmark trials which led to their FDA approval, and the strength of the evidence per National Comprehensive Cancer Network (NCCN), which is broadly utilized by medical oncologists and hematologists in their daily practice.

Prognostic Impact of Programmed Death-ligand 1 and Surrounding Immune Status on Stage I Lung Cancer

BackgroundThe programmed death 1/programmed death-ligand 1 (PD-L1) pathway reportedly is as an important factor determining effects of immunotherapy; however, its prognostic impact is controversial, and its association with the surrounding immune microenvironment has not yet been elucidated. Patients and MethodsWe retrospectively analyzed 126 patients with pathologic stage I non–small-cell lung cancer. Patients with lepidic-dominant adenocarcinoma were excluded. PD-L1 expression was evaluated with immunohistochemistry correlated with clinicopathologic features and surrounding immune microenvironment status, including CD4, CD8, regulatory T cells, and human leukocyte antigen class I. Factors affecting prognosis were assessed by Kaplan-Meier and Cox regression analyses. ResultsTwenty-three (18.3%) patients were positive for PD-L1 expression. No significant correlation was observed between PD-L1 expression and the surrounding immune microenvironment status. The PD-L1–positive group had a worse prognosis than the PD-L1–negative group (5-year recurrence-free survival rates, 63.4% vs. 81.0%; P = .061). Among surrounding immune cells, intratumoral CD8 status had the strongest impact on prognosis (P = .12). In the intratumoral CD8–high group, PD-L1 expression demonstrated no significant prognostic impact, whereas in the intratumoral CD8–low group, patients positive for PD-L1 demonstrated a significantly worse prognosis than those negative for PD-L1 (5-year recurrence-free survival rates, 41.7% vs. 78.6%; P = .034). Multivariable Cox regression analysis revealed that ‘PD-L1–positive and intratumoral CD8–low’ status was an independent prognostic factor (hazard ratio, 3.80; 95% confidence interval, 1.22-10.5; P = .023). ConclusionsThe prognostic impact of the PD-1/PD-L1 pathway may be distinct according to concurrent intratumoral CD8 status.

Manipulation of the immune system by non-small cell lung cancer and possible therapeutic interference.

Pulmonary carcinomas have developed mechanisms by which they escape the attack of immune cells. Immune checkpoint molecules programmed death 1 - programmed death ligand 1 (PD1-PDL1) and the cytotoxic T-lymphocyte antigen 4 system have gained attention. The expression of PDL1 by tumor cells causes immune tolerance, and further influences the microenvironment via orchestration by cytokines. Therapy with PDL1 antibodies could restore the cytotoxicity of T-lymphocytes towards tumor cells. Many patients will respond to this treatment. However, resistance mechanisms will counteract this therapy. New investigations have identified additional immune checkpoint inhibitors such as lymphocyte activation gene 3 and T cell immunoglobulin and mucin-domain containing-3. Tumor cells also induce tolerance by manipulating cells of the innate immune system. Macrophages are polarized to tumor-friendly M2, neutrophils into N2 types, and dendritic cells and myeloid suppressor cells are switched to assist tumor cells. Regulatory T cells enter the tumor microenvironment and signal tolerance to cytotoxic cells, inhibiting the influx of NK cells. Soluble mediators either released by tumor cells or cells of the tumor stroma induce immune tolerance, examples including tryptophan and indolamine dioxygenases, arginine and adenosine. Treatment options to counteract these molecules are currently being tested. The tumor stroma has been classified as immune-inflamed, immune-excluded, and immune-desert types. The latter might be switched to an inflamed type by induction of tertiary lymph follicles. Dendritic cells and macrophages normally phagocytose tumor antigens, but inhibitors of phagocytosis can block this. Interference with these molecules is another option for re-establishing the cytotoxic action of the immune system against tumor cells. In this review we will discuss these aspects with a special emphasis on non-small cell lung cancer.

PD-L1 expression in tumor infiltrated lymphocytes predicts survival in triple-negative breast cancer

ObjectiveTriple-negative breast cancer (TNBC), a complex and highly aggressive subtype of breast cancer, generally has the poorest clinical outcome, there is a pressing need for more effective therapeutic strategies. Immune checkpoint inhibitors against programmed death 1/programmed death ligand 1 (PD1/PDL1) have revolutionized treatment of several solid tumours, such as non-small cell lung carcinoma (NSCLC), renal, malignant melanoma. However, no checkpoint inhibitors were previously approved for the treatment of TNBC. So far, very limited data have reported PDL1 (SP142) expression and its relationship with clinicopathological behaviors and survival in TNBC. MethodsPD-L1(SP142) immunohistochemistry was performed on 223 TNBC cases and assessed in tumour cells(TC) as well as tumor-infiltrating lymphocytes(TILs).The relationships between PD-L1 expression and clinicopathological characteristic both in TC and TILs. Futhermore,we also explored the effect of PD-L1 expression on prognosis as illustrated by overall survival(OS). ResultsPD-L1 expression was detected in both tumor cells and TILs at a ratio of 8.5 % and 25.1 % respectively. PD-L1 expression in TILs was related to histological grade and abundance of TILs. Tumor cell expression of PD-L1 was not associated with outcome. While PD-L1 expression in TILs and lymphnode transfer were associated with a poor outcome, and PD-L1 expression was an independently prognostic of overall survival (OS) (HR = 0.867, P = 0.029). ConclusionPD-L1 expression in TILs, but not in tumor cells, was a poor prognostic factor in TNBC. These data provide further impetus for assessing immunotherapy in TNBC, in view of the clinical significance of the expression of PD-L1 (SP142) in TNBC.

PD-1 and PD-L1 Expression in Male Breast Cancer in Comparison with Female Breast Cancer.

BackgroundMale breast cancer is rare, as it represents less than 1% of all breast cancer cases. In addition, male breast cancer appears to have a different biology than female breast cancer. Programmed death-1 (PD-1) and its ligand, programmed death-ligand 1 (PD-L1), seem to have prognostic and predictive values in a variety of cancers, including female breast cancer. However, the role of PD-1 and PD-L1 expression in male breast cancer has not yet been studied.ObjectivesTo compare PD-1 and PD-L1 expression in male breast cancer to female breast cancer and to evaluate prognostic values in both groups.Patients and MethodsTissue microarrays from formalin-fixed paraffin-embedded resection material of 247 female and 164 male breast cancer patients were stained for PD-1 and PD-L1 by immunohistochemistry.ResultsPD-1 expression on tumor-infiltrating lymphocytes was significantly less frequent in male than in female cancers (48.9 vs. 65.3%, p = 0.002). In contrast, PD-L1 expression on tumor and immune cells did not differ between the two groups. In male breast cancer, PD-1 and tumor PD-L1 were associated with grade 3 tumors. In female breast cancer, PD-1 and PD-L1 were associated with comparably worse clinicopathological variables. In a survival analysis, no prognostic value was observed for PD-1 and PD-L1 in either male and female breast cancer. In a subgroup analysis, female patients with grade 3/tumor PD-L1-negative or ER-negative/immune PD-L1-negative tumors had worse overall survival.ConclusionsPD-1 seems to be less often expressed in male breast cancer compared to female breast cancer. Although PD-1 and PD-L1 are not definite indicators for good or bad responses, male breast cancer patients may therefore respond differently to checkpoint immunotherapy with PD-1 inhibitors than female patients.

Evaluation of rare but severe immune related adverse effects in PD-1 and PD-L1 inhibitors in non-small cell lung cancer: a meta-analysis.

Programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1) inhibitor therapy is showing marked efficacy in advanced non-small cell lung cancer (NSCLC). Meanwhile, it is concomitant with distinctive immune-related adverse effects. We aim to describe the incidence of pneumonitis and other rare but severe immune-related adverse effects (IRAEs), as well as treatment related deaths. In addition, we analyze the differences in incidence of pneumonitis between PD-1 and PD-L1 inhibitors and standard-of-care chemotherapy. PubMed was searched up to 24 March 2017 for clinical trials of PD-1 inhibitors (nivolumab and pembrolizumab) and PD-L1 inhibitors (atezolizumab, avelumab and durvalumab) in treatment of NSCLC. Besides, references of relevant articles were screened. Finally, 22 trials were included in our study, 14 with data of pneumonitis, 19 with other severe IRAEs or treatment related deaths and 5 with control groups. Incidence of all-grade pneumonitis was 2.9% (95% CI, 2.0-4.8%) and grade 3 or higher pneumonitis 2.0% (95% CI, 1.0-2.0%). Incidence of all-grade pneumonitis in PD-1 and PD-L1 inhibitor therapy (n=1,313) was significantly higher than that in chemotherapy (n=918) (OR=2.35, 95% CI, 1.32-4.20, P=0.004), but had no significance in grade 3-5 pneumonitis. Incidence of cardiorespiratory arrest (n=537) was 1.0% (95% CI, 0-2.0%), cardiac failure (n=214) 2.0% (95% CI, 1.0-5.7%), myocardial infarction (n=402) 1.0% (95% CI, 0-3.8%), stroke (n=135) 2.0% (95% CI, 0-13.0%), disease progression (n=391) 1.0% (95% CI, 0-2.9%), pancreatitis (n=700) 1.0% (95% CI, 0-2.0%) and severe skin reactions (n=836) 2.0% (95% CI, 1.0-3.8%). Incidence of treatment related deaths was 0.7%. Immune related adverse effects can on occasion be life-threatening even though usually rare. Incidence of pneumonitis in PD-1 and PD-L1 inhibitors was significantly higher than that in chemotherapy. More studies should be conducted to investigate the incidence of these rare but life-threatening IRAEs.