Programmed Death-ligand 1 Expression Research Articles

Effect of circulating tumor cells in clinically stable patients on the conundrum of recurrence with cellular residual disease.

e15040 Background: Despite no evidence of disease by radiological imaging, up to 30% breast cancer cases are known to relapse after treatment with a curative intent. The presence of CTCs in stage I-II cancer patients signals the activation of extravasation and invasion process leading to micro-metastasis and may lead to poor outcome. CTCs in blood circulation at any stage of cancer indicate detectable Minimal Cellular Disease (MCD). Thus the longitudinal investigation of patients with such biomarker remains highly implicative to predict the recurrence, therapy escalations, and dose modifications. The expression of Program Death - Ligand 1 (PD-L1) on CTCs is a dynamic biomarker and they may escape the elimination by immune system, indicative of progression of metastatic signature. Methods: Retrospectively, ina cohort of 20 cancer patients (e.g. lung, colon-rectal, breast, stomach, etc.) who recently underwent treatment were investigated for the presence of CTCs using CDSCO approved OncoDiscover platform having multi-components conjugated with anti EpCam antibody on magnetic nanoparticles. All patients represented clinically stable disease from previous radiological findings. CTCs enumeration assay was performed using CD45, EpCAM+, and CK18 and over-expression of PD-L1 in1.5 ml of peripheral blood using automated motorized Zeiss fluorescence microscopy. Results: In spite of 'no radiological' findings with clinically stable disease, out of 20 selected patients, 75% (n=15) showed at least 1 CTC. While, 55% (n=11) patients were detected with 1 CTC, 5% patients (n=1) with 2 CTCs, and 15% patients (n=3) were identified with 3 CTCs. In addition, 50% (n=10) of patients demonstrated with PD-L1 expression on CTCs; 1 patient exhibited a CTC cluster. Conclusions: Patients showed CRD in spite of a stable disease, which is an indication of progression of localized disease transforming from primary to secondary. The longitudinal monitoring of patients for CTCs with PD-L1 expression may reveal ‘real time’ residual disease, progression, regression, and actual response to the treatment. CRD monitoring can improve the curative intent by improving PFS and OS in solid cancers.

PD-L1 regulates tumor proliferation and T-cell function in NF2-associated meningiomas.

Programmed death-ligand 1 (PD-L1) expression is an immune evasion mechanism that has been demonstrated in many tumors and is commonly associated with a poor prognosis. Over the years, anti-PD-L1 agents have gained attention as novel anticancer therapeutics that induce durable tumor regression in numerous malignancies. They may be a new treatment choice for neurofibromatosis type 2 (NF2) patients. The aims of this study were to detect the expression of PD-L1 in NF2-associated meningiomas, explore the effect of PD-L1 downregulation on tumor cell characteristics and T-cell functions, and investigate the possible pathways that regulate PD-L1 expression to further dissect the possible mechanism of immune suppression in NF2 tumors and to provide new treatment options for NF2 patients. PD-L1 is heterogeneously expressed in NF2-associated meningiomas. After PD-L1 knockdown in NF2-associated meningioma cells, tumor cell proliferation was significantly inhibited, and the apoptosis rate was elevated. When T cells were cocultured with siPD-L1-transfected NF2-associated meningioma cells, the expression of CD69 on both CD4+ and CD8+ T cells was partly reversed, and the capacity of CD8+ T cells to kill siPD-L1-transfected tumor cells was partly restored. Results also showed that the PI3K-AKT-mTOR pathway regulates PD-L1 expression, and the mTOR inhibitor rapamycin rapidly and persistently suppresses PD-L1 expression. Invivo experimental results suggested that anti-PD-L1 antibody may have a synergetic effect with the mTOR inhibitor in reducing tumor cell proliferation and that reduced PD-L1 expression could contribute to antitumor efficacy. Targeting PD-L1 could be helpful for restoring the function of tumor-infiltrating lymphocytes and inducing apoptosis to inhibit tumor proliferation in NF2-associated meningiomas. Dissecting the mechanisms of the PD-L1-driven tumorigenesis of NF2-associated meningioma will help to improve our understanding of the mechanisms underlying tumor progression and could facilitate further refinement of current therapies to improve the treatment of NF2 patients.

Association of PD-L1 Expression with Clinicopathologic Characters in Gastric Cancer: A Comprehensive Meta-analysis.

The expression level of programmed death ligand-1(PD-L1) in patients with gastric cancer is the key to determining the use of immune drugs. The relationship between PD-L1 expression level and clinical characteristics is worth exploring. By setting the search terms correlated to PD-L1 and gastric cancer, a nearly comprehensive search was carried out in four major databases, and the deadline for searching was September 1, 2022. The retrieved documents were further screened by strict inclusion and exclusion criteria after removing the duplication. Next, the quality of the included studies was evaluated with the Newcastle-Ottawa Scale (NOS) scale. Finally, the STATA15.1 software was used to process data and draw plots, and the odds ratios (ORs) were adopted to assess the pooled effect size. A total of 85 works of literature were included in this study through screening strictly, and detailed data were extracted after evaluating the quality of the literature. The process of analysis was conducted in the whole population, Asia-Africa population, European and American population, and Asian population with CPS≥1, amd all found that the expression of PD-L1 in gastric cancer was correlated with age, tumor size, EBV infection, Her-2 expression and microsatellite status. However, the subgroup of the region also found some differences in Asian and Western regions, which was interesting and worth studying further. The included research of this study did not have significant publish bias. After careful analysis, this study found that age (>60 years), tumor size (>5cm), EBV infection (+), Her-2 expression (+), microsatellite status (MSI), and mismatch repair status (dMMR) were risk factors for positive expression of PD-L1 in gastric cancer.

Discrepancies in therapeutic indications for the same oncology drugs among FDA, EMA, and Brazilian agency.

e23035 Background: Divergent marketing approvals for oncology drugs among prominent agencies can prompt questions, especially when they are grounded in the same evidence. The aim of this study was to evaluate and compare the assessment and approval processes for novel products and indications by the FDA, EMA, and the Brazilian Health Regulatory Agency (ANVISA). Methods: Therapeutic indications for FDA-approved anticancer drugs from January 2019 to December 2023 were identified. Data, including approval dates, details on authorization procedures and evidence presented, were extracted from the databases of the FDA, EMA, and ANVISA. Only approvals for non-hematologic solid tumors were considered. All data were publicly available, and ethical approval was not required. No patient involvement occurred in this study. Results: Between 2019 and 2023, the FDA granted approval for 154 therapeutic indications for marketing authorization, resulting from 148 pivotal trials. The predominant cancer types during this period were non-small cell lung cancer (31 approvals [20.1%]). Most trials were in phase III (66.8%) and randomized (68.1%). Additionally, 41 (26.6%) received accelerated approvals, with 6 subsequently obtaining regular approvals. Among the therapies, 66 trials (42.8%) involved active comparators, while 53 (34.4%) and 35 (22.7%) were single-arm and placebo-controlled trials, respectively. Approximately half (74 [48%]) of the therapies were approved for metastatic first-line treatment, 54 (35%) for second-line treatment, and the rest for neoadjuvant and/or adjuvant treatment. Regarding endpoint characteristics supporting approval, the most prevalent was a combination of objective response rate (ORR) + duration of response (DoR) (38 [24.6%]), followed by progression-free survival (PFS) + overall survival (OS) (31 [20.1%]). When comparing the 154 FDA-approved indications, 50 (32.4%) were not approved by EMA, and 60 (38.9%) were not approved by ANVISA. Furthermore, in 33 cases (21.4%), there were disparities in clinical indications between the FDA and EMA, primarily related to the target population specification, with 10 cases (6.4%) attributed to programmed death ligand-1 (PD-L1) expression. Notably, in these instances, the FDA approved the drug regardless of PD-L1 expression, while the EMA required a percentage of cells with PD-L1 expression. In all these cases, ANVISA aligned with the FDA's assessment. Conclusions: Significant clinical disparities were identified in the outcomes of the approval process for oncology products among the FDA, EMA, and ANVISA. Additional efforts are needed to standardize decision-making across regulatory systems.

Envafolimab plus chemotherapy as neoadjuvant therapy for resectable esophageal squamous cell carcinoma (ESCC): A prospective, single-arm, phase II study.

e14633 Background: Currently, chemotherapy plus PD-1 inhibitor immunotherapy has become a promising option in the neoadjuvant setting of resectable ESCC, nevertheless, the PD-ligand 1 (PD-L1) blockade-based combination has rarely been investigated to date. Envafolimab is the first and only globally approved subcutaneous (SC) PD-L1 inhibitor, which has shown satisfactory efficacy and safety profile in tumors. This Simon’s two-stage, phase II study explored the safety and feasibility of SC administration of envafolimab as an alternative to intravenous (IV) administration of PD-1/PD-L1 inhibitors in the neoadjuvant therapy of resectable ESCC. Here, we reported the results of the stage 1. Methods: In this Simon’s two-stage, phase II study, patients initially treated with locally advanced and resectable (stage II-IVA) ESCC were enrolled and received envafolimab (300mg, SC, day 1), albumin-bound paclitaxel (130mg/m2, IV, days 1 and 8), and carboplatin (AUC = 5, day 1) every 3 weeks for 3 cycles. The primary endpoints were safety and pathological complete response (pCR). A Simon’s two-stage design was utilized with following assumptions. Target accrual was 13 patients in the first stage (If 3 or more patients had pCR in stage 1, study could continue in stage 2), total 34 patients were enrolled in the stage 2. Secondary endpoints were major pathological response (MPR). Safety was assessed by adverse events (AEs) and postoperative complications. Results: Between October 2022 and April 2023, 13 (81.3%) of 16 enrolled patients completed neoadjuvant therapy and underwent surgery. All 13 (100%) surgical patients underwent successful R0 resection; of whom, 8 (61.5%) achieved pCR and 9 (69.2%) achieved MPR, respectively. Downstaging occurred in 10 (76.9%) of 13 patients. pCR and MPR were identified to be associated with tumor downstaging but not with PD-L1 expression. CPS levels in MPR and pCR group were significantly higher than that in Non- MPR and Non-pCR group. Grade 3-4 treatment-related AEs (TRAEs) and immune-related AEs (IrAEs) occurred in 12.5% and 37.5% of 16 patients, respectively. 10 (76.9%) of 13 patients reported postoperative complications. No treatment-related surgical delay or death occurred. Conclusions: Envafolimab plus chemotherapy as neoadjuvant therapy demonstrated promising antitumor activity for resectable ESCC with high rates of pCR, MPR and R0 resection, as well as acceptable tolerability. Based on the encouraging efficacy of our regimen in the first stage, we will continue the enrollment of patients in stage 2. Keywords: Esophageal squamous cell carcinoma; Envafolimab; Neoadjuvant therapy; Chemotherapy Clinical trial information: NCT05552651 .

Mitochondrial metabolism blockade nanoadjuvant reversed immune-resistance microenvironment to sensitize albumin-bound paclitaxel-based chemo-immunotherapy

Currently, the efficacy of albumin-bound paclitaxel (PTX@Alb) is still limited due to the impaired PTX@Alb accumulation in tumors partly mediated by the dense collagen distribution. Meanwhile, acquired immune resistance always occurs due to the enhanced programmed cell death-ligand 1 (PD-L1) expression after PTX@Alb treatment, which then leads to immune tolerance. To fill these gaps, we newly revealed that tamoxifen (TAM), a clinically widely used adjuvant therapy for breast cancer with mitochondrial metabolism blockade capacity, could also be used as a novel effective PD-L1 and TGF-β dual-inhibitor via inducing the phosphorylation of adenosine 5ʹ-monophosphate-activated protein kinase (AMPK) protein. Following this, to obtain a more significant effect, TPP-TAM was prepared by conjugating mitochondria-targeted triphenylphosphine (TPP) with TAM, which then further self-assembled with albumin (Alb) to form TPP-TAM@Alb nanoparticles. By doing this, TPP-TAM@Alb nanoparticles effectively decreased the expression of collagen in vitro, which then led to the enhanced accumulation of PTX@Alb in 4T1 tumors. Besides, TPP-TAM@Alb also effectively decreased the expression of PD-L1 and TGF-β in tumors to better sensitize PTX@Alb-mediated chemo-immunotherapy by enhancing T cell infiltration. All in all, we newly put forward a novel mitochondrial metabolism blockade strategy to inhibit PTX@Alb-resistant tumors, further supporting its better clinical application.

The clinical application of circulating tumor cells (CTCs) for immunotherapy in advanced pancreatic cancer.

e14541 Background: Circulating tumor cell (CTCs) has the potential utility for screening, prognostic and predictive assessment, and offers the potential for personalized management. This trial aimed to evaluate the prognostic and predictive impact of programmed cell death ligand 1 (PD-L1) positive CTCs in patients with pancreatic ductal adenocarcinoma (PDAC). Methods: Twenty-three heavily treated advanced PDAC patients were randomized to receive camrelizumab combined with apatinib or capecitabine, or placebo plus capecitabine until disease progression or unacceptable toxicity, and peripheral blood CTCs samples were collected at baseline and after treatment. Forty-nine CTCs samples from 23 recruited advanced PDAC patients were detected by subtraction enrichment and immunostaining-FISH (SE-iFISH). PD-L1 expression level also was evaluated in tumor tissue samples by Immunohistochemistry (IHC). Investigator-assessed 6-month overall survival (OS) rate and 3-month progression-free survival (PFS) rate was evaluated. Results: The positive detection rate of CTCs in 23 PDAC patients was 95.7%. The cell sub-types of sizes of CTC analysis showed that 58.6% CTCs was the small CTCs (Diameter < 5μm). CTCs karyotypes analysis exhibited that triploid small CTCs were the main karyotype (41.2%) in small CTC, and pentaploid large CTCs was the major karyotype (74.7%) in large CTCs. PD-L1+ CTCs were detected in 43.5% of PDAC patients. Tissue PD-L1 positive detection rate was 50% (CPS > 1%) in available tissue samples(n=10). The presence of PD-L1+ CTCs cohort exhibited a significant increase in 6-month OS rate (80% versus 38.5%, P < 0.05) and 3-month PFS rate (70% versus 23.1%, P < 0.05) compared to PD-L1- CTCs cohort. Compared with the PD-L1- CTCs patients, the combination therapy camrelizumab markedly improved the 6-month OS rates (75% versus 50%) and 3-month PFS rate (62.5% versus 25%) in PD-L1+ CTC patients. Conclusions: PD-L1+ CTCs could be considered as a favorable prognostic marker in advanced PDAC. These results suggest that PD-L1+ CTCs might be used as a predictor of the efficacy of cancer immunotherapy in advanced PDAC, and provide a new monitoring method for the precise treatment of advanced PDAC. The expanding sample size test is now ongoing. Clinical trial information: ChiCTR1900024095 .

Hyaluronic acid hydrogel to modulate tumor cell clustering and programmed death ligand 1 signaling in cancer stem cells.

e14584 Background: The root of malignancy lies in the extracellular matrix (ECM) surrounding the stromal cells. Thus, current therapeutic targets manipulate abnormal tumor microenvironments (TME), which nourish cancer stem cells (CSC) and induce tumor cell clustering (TCC). Notably, despite the first line of clinical therapy with surgery and chemotherapy, uncontrolled self-renewal of CSCs, conversion of non-CSCs to CSCs, and TCC trigger cancer recurrence. The transmembrane glycoprotein CD44 is thought to be a potential master regulator in cancer recurrence as it interacts with hyaluronic acid (HA) in TME, expresses aberrantly on CSCs, induces TCC by homophilic interactions like Plakoglobin despite less understanding on their crosstalk, and promotes expression of pro-tumorigenic factor programmed death ligand 1 (PD-L1). Notably, CD44 is expressed in multiple isoforms, and splice isoform switching of CD44 dictates the properties of CSC, which still needs to be clarified. Hence, we aimed to characterize CSCs based on CD44 isoform expression, investigate the crosstalk between CD44 and Plakoglobin, and then design a novel injectable HA hydrogel that can disguise TME and suppress PD-L1 to combat cancer recurrence. Methods: To characterize CSCs, we prepared different scaffolds of HA of varied molecular weights and other ECM proteins, cultured cancer cells (MDA-MB-231, HeLa), and determined the expression of CD44 isoforms. We sorted CD44+/CD24- expressing CSC by flow cytometry. We implemented immunoprecipitation to detect the interaction between CD44 and Plakoglobin. We created a novel HA hydrogel composed of low and very high molecular weight HA, thiolated gelatin, and other components crosslinked with PEGDA. Using a torsional rheometer, we measured matrix stiffness. We assessed the cell proliferation efficiency of CSC by a colony-forming assay. Results: The study disclosed that CD44 isoforms expressed differently based on ECM properties. Matrix stiffness dictated CD44 isoform expression. We observed that CD44 interacted with Plakoglobin. CD44 ablation upregulated Plakoglobin significantly. Tumor suppressor p53 played a significant role in CD44-Plakoglobin crosstalk. We observed that the injectable hydrogel modulated CD44-Plakoglobin signaling and inhibited TCC, likely promoting anoikis. The hydrogel affected CD44 splicing and modified the activity of the CD44 intracellular domain, which interacts with PD-L1 and thus suppressed PD-L1 expression significantly in CSC. Conclusions: Currently, antibodies targeting PD-1/PD-L1 signaling have been clinically approved for various cancers. However, this regimen of treatment is expensive. We report a novel injectable hydrogel that can disguise TME, modulate CSCs and PD-L1, and may advance an alternative cost-effective avenue for cancer immunotherapy.

Impact of the tumor proportion score (TPS) and the combined positive score (CPS) on the use of immunotherapy in patients with metastatic non-small cell lung cancer.

e14611 Background: Expression of programmed cell death ligand 1 (PD-L1) in non-small cell lung cancer (NSCLC) has often been measured by the Tumor Proportion Score (TPS) (1). Recently, the Combined Positive Score (CPS), which evaluates PD-L1 expression in tumor and inflammatory cells and applies to other types of cancer including gastric and head and neck cancers, was found to be equally predictive of the response to immunotherapy in NSCLC (1). In this study, we aimed to conduct a single center retrospective analysis to evaluate the clinical use and impact of using TPS and CPS data in patients with metastatic NSCLC. Methods: Patients with NSCLC who had TPS and CPS scores and received PD-1/PD-L1 inhibitors between 2021-2022 as a monotherapy or in combination with chemotherapy were included. Patients’ data was retrieved from the electronic medical record data and analysis included histopathological data, lung cancer surgical history, presence of EGFR mutation, ALK mutation, Ki67, use of adjuvant chemotherapy, type of immunotherapy used, and development of immune checkpoint inhibitor- related toxicity and treatment as applicable. TPS and CPS positivity was defined as >1 % and >1 respectively. Statistical methods employed included descriptive approaches such as calculated means as well as the Kaplan-Meier estimate. Results: 40 patients with NSCLC were included. Patients’ age ranged from 19 to 82 years old with an average age of 64.3 years old. Most patients had adenocarcinoma (65 %) and were at stage IV (72.5 %). TPS positivity was identified in 29 patients (72.5 %) and CPS positivity was identified in 35 patients (87.5 %). Patients received immunotherapy mostly as first or second line of treatment (90 %). Immune checkpoint inhibitors received by patients were pembrolizumab (50 %), nivolumab (35 %), atezolizumab (12.5 %), and durvalumab (2.5 %). The median overall survival was 16, 12, and 17 months in the <1 %, 1-49 % and > 49 % TPS groups respectively (p= 0.354); while the median overall survival was 11, 16 and 17 months in the <1, 1-49, and > 49 CPS groups respectively (p= 0.417). It is critical to highlight that there were 7 patients (17.5 %) with TPS of zero who had CPS positivity (score range: 1-10). Most of these patients had adenocarcinoma (71.4 %), received pembrolizumab or atezolizumab (85.7 %) and had a median survival of 16 months. Conclusions: The Combined Positive Score (CPS) has proven to be an effective method in evaluating the level of expression of PD-L1 in NSCLC (1,2). Similar to TPS, CPS provides critical information that can be applied to guide the use of immunotherapy, and which can greatly impact patients with NSCLC. 1. De Marchi et al., 2021. 2. Ulas et al., 2023.

Relationship between immune-inflammatory markers and clinical features and deepness of tumor response and prognosis of patients with PD-L1 ≥50% metastatic NSCLC receiving first-line immunotherapy.

e14547 Background: Patients with programmed cell death-ligand 1 (PD-L1) ≥50% metastatic non-small cell lung cancer (NSCLC) treated with first-line immunotherapy have heterogeneous clinical assessment and outcomes. In this study, we sought to identify features of patients with metastatic NSCLC who achieved high deepness of response (HDPR) to first-line immunotherapy, and how these might differ from features predictive of non-high deepness of response (NHDPR). The influence of clinical features on prognosis of patients with PD-L1 ≥50% were further clarified. Methods: This retrospective study analyzed patients with PD-L1≥50% metastatic NSCLC treated with first-line immunotherapy at Beijing Tiantan Hospital between July 2020 and December 2023. All the patients had at least one measurable lesion in lung according to the Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. HDPR was defined as deepness of lung tumor response ≥50%, while NHDPR was defined as deepness of lung tumor response <50% or tumor enlargement. Tumor PD-L1 expression, target mutation, neutrophil-to-lymphocyte ratio (NLR), lactic dehydrogenase (LDH) level, and other prognostic variables were analyzed to identify characteristics enriched in patients achieving HDPR compared to NHDPR. We also investigated the effects of these variables on first-line progression-free survival (PFS) and overall survival (OS) of the patients. Results: A total of 17 patients were included in our retrospective analysis. Seven (41.2%) patients achieved HDPR (range: -50%, -72%) and ten (58.8%) patients achieved NHDPR (range: -13%, -45%). Seven (41.2%) patients had central nervous system (CNS) metastases at the first diagnosis of lung malignancy, and their CNS target lesions shrinkages were observed after therapy (range: -32%, -100%). Lower Th/Ts ratio ( P=0.01) and drug resistance mutations (TP53/KRAS/EGFR) ( P=0.001) were found enriched for NHDPR compared to HDPR. However, no differences were found in tumor PD-L1 expression, NLR, LDH, B lymphocyte subset, NK cell subset, pathological type, T-stage, smoking index, ECOG score, immunotherapeutic schemes, or CNS metastases between the two groups ( P>0.05). With a median follow-up of 26.0 months (range: 17.2-34.8 months), the median first-line PFS and OS were 9.0 months (95% CI: 5.0-13.0) and not reached (NR), respectively. The NLR was identified as an independent prognostic factor on first-line PFS. Patients with an NLR≥4 exhibited a worse median PFS (7.0 months vs. NR; P=0.033; 95%CI: 1.2-80.2) than those with an NLR<4 following first-line immunotherapy. Conclusions: Among patients with PD-L1≥50% metastatic NSCLC who received first-line immunotherapy, lower Th/Ts ratio and drug resistance mutations showed a diminished tumor response and higher NLR ratio exhibited a worse median PFS.

Tislelizumab combined with chemotherapy in advanced thymic tumors.

e20139 Background: Thymic tumors refer to tumors derived from thymic epithelial cells, including thymoma and thymic carcinoma. Most cases in advanced stages when detected, and treatment is still controversial. Since 2018, immunotherapy has gradually been used for a variety of solid tumors and the curative efficacy has been notable. The efficacy of immunotherapy is increasingly improved with the increased expression of programmed death-ligand 1 (PD-L1) by tumor cells. The thymus is an immune-rich organ. PD-L1 expression ranges from 23% to 92% in thymoma, and from 36% to 100% in thymic carcinoma. Thus, immunotherapy has been implicated as having broad prospects in the treatment of thymic tumors. Tislelizumab is an inhibitor of PD-1, which has shown preliminary anti-tumor effects in various solid tumors. The combination of immunotherapy and chemotherapy has produced excellent anti-tumor activity for various types of tumors. However, there is a lack of clinical trial data to support the application of tislelizumab for the treatment of advanced thymic tumors. In this article, the efficacy and safety of tislelizumab combined with chemotherapy were analyzed in eight patients with advanced thymic tumors to provide data for the use of this monoclonal antibody as first-line treatment of advanced thymic tumors. Methods: Here, after obtaining fully informed consent, we report cases involving eight patients with advanced thymic tumors treated with tislelizumab combined with chemotherapy. The clinical characteristics, lesion changes, treatment process, drugs used, drug efficacy, complications or adverse reactions were recorded and followed up to evaluate the efficacy and safety of tislelizumab combined with chemotherapy in the treatment of advanced thymic tumors. Results: This article reports eight cases of advanced thymic tumor treated with tislelizumab combined with chemotherapy. Two patients received tislelizumab combined with chemotherapy as first-line treatment, and the remaining six patients were treated with tislelizumab after poor response to chemotherapy. Five patients achieved a partial response to the combined treatment. Of these, the partial response was retained in three patients after switching to tislelizumab monotherapy. The remaining three patients displayed stable disease after the combined treatment. There were no serious immune-related adverse events during treatment. The side effects of tislelizumab combined with chemotherapy were well tolerated. Conclusions: No clinical study of immunotherapy combined with standard chemotherapy as first-line treatment for advanced unresectable or metastatic thymic epithelial tumors has been described. This article provides strong evidence for the early application or even first-line use of tislelizumab combined with chemotherapy for advanced thymic epithelial tumors. More clinical studies are needed to evaluate the efficacy and safety of tislelizumab in thymic tumors.

PD-L1 immunohistochemistry in gastric cancer: Comparison of combined positive score and tumor area positivity across 28-8, 22C3, and SP263 assays.

2625 Background: The clinical application of programmed death-ligand 1 (PD-L1) immunohistochemistry is complicated by multiple available assays and different testing platforms, scoring algorithms, and cut-offs applied. This study assessed the analytical comparability of three commercially available PD-L1 assays (28-8, 22C3, and SP263) and two scoring algorithms used in gastric cancer (GC). Methods: Serial sections of 100 commercially procured GC samples, selected by the 28-8 assay to represent the dynamic range of PD-L1 expression, were stained with the three in vitrodiagnostic (IVD)-grade PD-L1 assays. Stained slides were blindly and independently evaluated by three trained pathologists for intra- and inter-reader assessment. Scoring was performed using the combined positive score (CPS) and tumor area positivity (TAP) methods, followed by statistical analysis. Digital image analysis (DIA) was used to objectively assess the technical performance of each assay by simulating CPS and TAP scoring methods using the HALO platform. Results: Comparable, specific, staining patterns were observed with the three PD-L1 assays. Pathologist assessment of PD-L1 positivity was reproducible in GC sample cohorts despite discernible variability in the observed staining intensity. When the same PD-L1 cut-offs were applied, inter- and intra-assay assessments of all three assays, using either CPS or TAP scoring methods, demonstrated moderate to almost-perfect (inter-assay Cohen’s kappa [κ] ranged from 0.47 to 0.83) and substantial to almost-perfect (intra-assay κ ranged from 0.77 to 1.00) agreement, respectively. Moreover, inter-pathologist evaluation showed a significant level of reproducibility (intraclass correlation coefficient (ICC) ≥0.92). DIA confirmed no difference in technical performance when specific digital algorithms were applied. Conclusions: This GC study highlights analytical concordance in PD-L1 testing among three major PD-L1 assays when TAP and CPS scoring algorithms are prospectively applied. Independently, DIA further supports the comparability of the technical performance of the assays. These observations support flexibility in cross-application of the different PD-L1 assays and scoring algorithms currently used to characterize PD-L1–positive GC samples.

Clinical outcomes and prognostic factors of concurrent chemoradiotherapy for anal squamous cell carcinoma in Japan.

Concurrent chemoradiotherapy (CCRT) is the standard treatment for locoregional anal squamous cell carcinoma (ASCC) in western countries. However, there have been few reports on the clinical outcomes of CCRT in Japan. This study aimed to evaluate the clinical outcomes of CCRT, prognostic factors, and the clinical impact of programmed cell death-ligand 1 (PD-L1) expression of ASCC in Japan. Patients with locoregional ASCC were enrolled between 2007 and 2017. All patients received CCRT consisting of ≥ 45Gy of radiation, 5-fluorouracil, and mitomycin C. Disease-free survival (DFS), overall survival (OS), and adverse events (AEs) were estimated. Expression of p16 and PD-L1 were assessed by immunohistochemical staining (IHC). This study included 36 patients, of whom 30 (83.3%) were female. Among the participants, 32 (88.9%) achieved complete clinical remission, while six (16.7%) experienced recurrence. The five-year DFS and five-year OS were 72.2% and 84.7%, respectively. Grades ≥ 3 serious AEs included neutropenia in 10 (27.7%) and perianal dermatitis in eight (22.2%). In a univariate analysis, male sex, lymph node metastasis, and large tumor size were significantly associated with worse outcome. In a multivariate analysis, tumor size was an independent factor associated with short DFS. Of the 30 patients whose biopsy specimens were available for IHC, 29 (96.7%) were positive for p16, and 13 (43.3%) were positive for PD-L1. However, PD-L1 expression did not show any clinical impact. The comparative etiology, clinical outcomes, and prognostic factors of CCRT observed in Japanese patients with locoregional ASCC were consistent with western data.

Molecular classification and biomarkers of outcome with immunotherapy in extensive-stage small-cell lung cancer: analyses of the CASPIAN phase 3 study

BackgroundWe explored potential predictive biomarkers of immunotherapy response in patients with extensive-stage small-cell lung cancer (ES-SCLC) treated with durvalumab (D) + tremelimumab (T) + etoposide-platinum (EP), D + EP, or EP in the randomized phase 3 CASPIAN trial.Methods805 treatment-naïve patients with ES-SCLC were randomized (1:1:1) to receive D + T + EP, D + EP, or EP. The primary endpoint was overall survival (OS). Patients were required to provide an archived tumor tissue block (or ≥ 15 newly cut unstained slides) at screening, if these samples existed. After assessment for programmed cell death ligand-1 expression and tissue tumor mutational burden, residual tissue was used for additional molecular profiling including by RNA sequencing and immunohistochemistry.ResultsIn 182 patients with transcriptional molecular subtyping, OS with D ± T + EP was numerically highest in the SCLC-inflamed subtype (n = 10, median 24.0 months). Patients derived benefit from immunotherapy across subtypes; thus, additional biomarkers were investigated. OS benefit with D ± T + EP versus EP was greater with high versus low CD8A expression/CD8 cell density by immunohistochemistry, but with no additional benefit with D + T + EP versus D + EP. OS benefit with D + T + EP versus D + EP was associated with high expression of CD4 (median 25.9 vs. 11.4 months) and antigen-presenting and processing machinery (25.9 vs. 14.6 months) and MHC I and II (23.6 vs. 17.3 months) gene signatures, and with higher MHC I expression by immunohistochemistry.ConclusionsThese findings demonstrate the tumor microenvironment is important in mediating better outcomes with D ± T + EP in ES-SCLC, with canonical immune markers associated with hypothesized immunotherapy mechanisms of action defining patient subsets that respond to D ± T.Trial registrationClinicalTrials.gov, NCT03043872.

Immune cell infiltration and inflammatory landscape in primary brain tumours

BackgroundPrimary malignant brain tumours are more than one-third of all brain tumours and despite the molecular investigation to identify cancer driver mutations, the current therapeutic options available are challenging due to high intratumour heterogeneity. In addition, an immunosuppressive and inflammatory tumour microenvironment strengthens cancer progression. Therefore, we defined an immune and inflammatory profiling of meningioma and glial tumours to elucidate the role of the immune infiltration in these cancer types.MethodsUsing tissue microarrays of 158 brain tumour samples, we assessed CD3, CD4, CD8, CD20, CD138, Granzyme B (GzmB), 5-Lipoxygenase (5-LOX), Programmed Death-Ligand 1 (PD-L1), O-6-Methylguanine-DNA Methyltransferase (MGMT) and Transglutaminase 2 (TG2) expression by immunohistochemistry (IHC). IHC results were correlated using a Spearman correlation matrix. Transcript expression, correlation, and overall survival (OS) analyses were evaluated using public datasets available on GEPIA2 in Glioblastoma (GBM) and Lower Grade Glioma (LGG) cohorts.ResultsSeven out of ten markers showed a significantly different IHC expression in at least one of the evaluated cohorts whereas CD3, CD4 and 5-LOX were differentially expressed between GBMs and astrocytomas. Correlation matrix analysis revealed that 5-LOX and GzmB expression were associated in both meningiomas and GBMs, whereas 5-LOX expression was significantly and positively correlated to TG2 in both meningioma and astrocytoma cohorts. These findings were confirmed with the correlation analysis of TCGA-GBM and LGG datasets. Profiling of mRNA levels indicated a significant increase in CD3 (CD3D, CD3E), and CD138 (SDC1) expression in GBM compared to control tissues. CD4 and 5-LOX (ALOX5) mRNA levels were significantly more expressed in tumour samples than in normal tissues in both GBM and LGG. In GBM cohort, GzmB (GZMB), SDC1 and MGMT gene expression predicted a poor overall survival (OS). Moreover, in LGG cohort, an increased expression of CD3 (CD3D, CD3E, CD3G), CD8 (CD8A), GZMB, CD20 (MS4A1), SDC1, PD-L1, ALOX5, and TG2 (TGM2) genes was associated with worse OS.ConclusionsOur data have revealed that there is a positive and significant correlation between the expression of 5-LOX and GzmB, both at RNA and protein level. Further evaluation is needed to understand the interplay of 5-LOX and immune infiltration in glioma progression.

Expression of PD-L1 (DAKO 28-8) in Urothelial Carcinoma of Urinary Bladder

Introduction: Around 90% of bladder cancers are urothelial carcinoma. Recent advancements in treatment have shifted towards targeted therapies, particularly immunotherapies targeting PD-L1 (Programmed Cell Death Ligand 1). PD-L1, a ligand for PD-1 receptors, helps cancer cells evade the immune system. Various factors, including genetic alterations, lead to its upregulation in cancer cells. Immunotherapies aim to block this pathway, making cancer cells more susceptible to the immune response. Objective: The study was designed to assess the frequency of PD-L1 expression by immunohistochemistry in urothelial carcinoma of urinary bladder and its association with histological grades. Methodology: This study was conducted at Department of Pathology, Pakistan Institute of Medical Sciences Islamabad. Fifty-six cases of urothelial carcinoma were included. Immunohistochemistry using PD-L1 Dako 28-8 clone was applied to prepared tissue sections. PD-L1 positivity was determined by brown membrane staining in tumor cells, scored using the Tumor Proportion Score (TPS). Results: The median patient age was 63±7 years, with the highest frequency (58.9%) of PD-L1 expression occurring in the age range of 56 to 65 years. However, there was no significant association between PD-L1 expression and age groups. Out of 56 cases, 64.3% had a TPS (Tumor Proportion Score) of ≥5%. Among the 76.7% high-grade cases, 72% had a TPS ≥5%, whereas 28% had a TPS <5%. Among the 23.2% low-grade cases, 61.5% had a TPS <5%, and 38.5% had a TPS ≥5%. Conclusion: Sixty-four percent urothelial carcinoma cases showed PD-L1 expression. Significant association (p value = 0.02) between PD-L1 expression and high-grade urothelial carcinoma was found using Pearson’s Chi-square test.

Expression of PD-L1 (DAKO 28-8) in Urothelial Carcinoma of Urinary Bladder

Introduction: Around 90% of bladder cancers are urothelial carcinoma. Recent advancements in treatment have shifted towards targeted therapies, particularly immunotherapies targeting PD-L1 (Programmed Cell Death Ligand 1). PD-L1, a ligand for PD-1 receptors, helps cancer cells evade the immune system. Various factors, including genetic alterations, lead to its upregulation in cancer cells. Immunotherapies aim to block this pathway, making cancer cells more susceptible to the immune response. Objective: The study was designed to assess the frequency of PD-L1 expression by immunohistochemistry in urothelial carcinoma of urinary bladder and its association with histological grades. Methodology: This study was conducted at Department of Pathology, Pakistan Institute of Medical Sciences Islamabad. Fifty-six cases of urothelial carcinoma were included. Immunohistochemistry using PD-L1 Dako 28-8 clone was applied to prepared tissue sections. PD-L1 positivity was determined by brown membrane staining in tumor cells, scored using the Tumor Proportion Score (TPS). Results: The median patient age was 63±7 years, with the highest frequency (58.9%) of PD-L1 expression occurring in the age range of 56 to 65 years. However, there was no significant association between PD-L1 expression and age groups. Out of 56 cases, 64.3% had a TPS (Tumor Proportion Score) of ≥5%. Among the 76.7% high-grade cases, 72% had a TPS ≥5%, whereas 28% had a TPS <5%. Among the 23.2% low-grade cases, 61.5% had a TPS <5%, and 38.5% had a TPS ≥5%. Conclusion: Sixty-four percent urothelial carcinoma cases showed PD-L1 expression. Significant association (p value = 0.02) between PD-L1 expression and high-grade urothelial carcinoma was found using Pearson’s Chi-square test.

Tislelizumab plus chemotherapy versus placebo plus chemotherapy as first line treatment for advanced gastric or gastro-oesophageal junction adenocarcinoma: RATIONALE-305 randomised, double blind, phase 3 trial

ObjectiveTo evaluate the efficacy and safety of tislelizumab added to chemotherapy as first line (primary) treatment for advanced gastric or gastro-oesophageal junction adenocarcinoma compared with placebo plus chemotherapy.DesignRandomised, double blind,...

STAT3 Expression and Its Correlation with PD-L1 Expression in Non-Hodgkin's Lymphoma and Hodgkin's Lymphoma at Dr. Saiful Anwar Regional Public Hospital in Malang, Indonesian Population.

Lymphomas are malignant lymphocyte neoplasms that globally account for 10% of cancers in individuals aged <20 years. Malignant lymphomas are divided into Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL). Despite the availability of many therapeutic modalities for lymphoma, such as Brentuximab vedotin, Nivolumab, and Pembrolizumab, it is still necessary to identify appropriate strategies with minimal side effects. Immunotherapy is a promising approach, exemplified by targeting JAK/STAT3 signaling, which can inhibit tumor growth and enhance antitumor immune responses. Hence, STAT3 (signal transducer and activator of transcription 3) is a promising therapeutic target. PD-L1 (programmed death-ligand 1), an immune checkpoint molecule, is used as a frontline treatment for various cancers. This study aims to determine STAT3 expression and its correlation with PD-L1 expression in NHL and HL to serve as a basis for further research on anti-STAT3 and its combination with other therapy targets. Samples were obtained from paraffin blocks of patients with confirmed diagnoses of NHL and HL, and then immunohistochemical staining was carried out with PD-L1 and STAT3 antibodies. The collected data were then analyzed using SPSS. Among the 10 HL patients, no patients (0%) expressed STAT3, while nine patients (90%) expressed PD-L1. Among the 10 NHL patients, 1 patient (10%) expressed STAT3, while six patients (60%) expressed PD-L1. There were no significant differences in STAT3 expression and PD-L1 expression between HL patients and NHL patients. There was no correlation between STAT3 and PD-L1 expression in HL and NHL because almost all STAT3 expressions were negative. Although this study revealed no differences between STAT3 and PD-L1 expression in HL and NHL and no significant correlation between STAT3 and PD-L1 expression in HL and NHL, this may serve as the basis for understanding the role of STAT3 and PD-L1 in the regulation of HL and NHL, which may be useful for further research targeting STAT3 and PD-L1 immunotherapy in HL and NHL.

Sulforaphane impaired immune checkpoint blockade therapy through activating ΔNP63α/PD-L1 axis in gastric cancer.

Sulforaphane (SFN) exerts anticancer effect on various cancers including gastric cancer. However, the regulatory effect of SFN on programmed death-ligand 1 (PD-L1) and checkpoint blockade therapy in gastric cancer have not been elucidated. Here we demonstrated that SFN suppressed gastric cancer cell growth both in vitro and in vivo study. SFN upregulated PD-L1 expression through activating ΔNP63α in gastric cancer cells. Further, we found that SFN impaired the anticancer effect of anti-PD-L1 monoclonal antibody (α-PD-L1 mab) on gastric cancer cells. These results uncover a novel PD-L1 regulatory mechanism and the double-edged role of SFN in gastric cancer intervention.