Programmed Death Receptor Ligand 1 Expression Research Articles

Preclinical development of novel PD-L1 tracers and first-in-human study of [68Ga]Ga-NOTA-RW102 in patients with lung cancers

BackgroundThe programmed cell death protein-1 (PD-1)/programmed death receptor ligand 1 (PD-L1) axis critically facilitates cancer cells’ immune evasion. Antibody therapeutics targeting the PD-1/PD-L1 axis have shown remarkable efficacy in various...

Efficacy and influencing factors of immunotherapy combined with chemotherapy and bevacizumab in patients with non-small cell lung cancer after epidermal growth factor receptor tyrosine kinase inhibitors treatment failure

Objective: To investigate the efficacy and influencing factors of immunotherapy combined with chemotherapy and bevacizumab in patients with non-small cell lung cancer (NSCLC) who failed epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) treatment. Methods: A retrospective analysis was made on the clinical data of 60 NSCLC patients who were treated with immunotherapy combined with chemotherapy and bevacizumab after EGFR-TKIs treatment failure in the Affiliated Cancer Hospital of Shandong First Medical University from January 2019 to March 2022. Patients were followed up by telephone or outpatient review up to October 1, 2022, with a median follow-up of 8.2 months (95%CI: 7.1-9.3). All 60 patients were followed up. The response evaluation criteria in solid tumors were used to evaluate the short-term efficacy. The adverse reactions of patients were evaluated according to the common terminology criteria for adverse events. The survival curve was drawn by Kaplan-Meier method. Cox proportional hazard regression models were utilized to analyze the influencing factors of progression-free survival (PFS). Results: Among the 60 NSCLC patients, 22 were males. The age ranged from 41 to 75 years, with a median age of 61 years. Eleven patients had partial response, 19 patients had stable disease and 30 patients had progressive disease. The median PFS was 8.2 months (95%CI: 7.2-9.2). The median PFS of patients with low expression of programmed death receptor-ligand 1 (PD-L1) [Tumor cell Proportion Score (TPS)<1%], moderate expression of PD-L1 (1%≤TPS≤49%), and high expression of PD-L1 (TPS≥50%) were 6.4 (95%CI: 4.8-8.0), 8.3 (95%CI: 7.3-9.3) and 10.6 months (95%CI: 7.2-14.1), respectively, and there were statistically significant differences (χ2=13.58, P<0.001). Multivariate Cox proportional risk regression model analysis showed that age>65 years old (HR=4.017, 95%CI: 1.468-10.992, P=0.007) was a risk factor for PFS in NSCLC patients who received immunotherapy combined with chemotherapy and bevacizumab after EGFR-TKIs treatment failure. Moderate expression of PD-L1 (HR=0.360, 95%CI: 0.139-0.930, P=0.035) and high expression of PD-L1 (HR=0.155, 95%CI: 0.039-0.625, P=0.009) were protective factors for PFS. Most of the treatment-related adverse reactions in the whole group were grade 1-2, including bone marrow suppression (n=24), nausea (n=25), decreased appetite (n=24), fatigue (n=22), vomiting (n=18), abnormal liver function (n=17), blood creatinine increased (n=10), and so on. These were tolerated by the patients. Conclusions: NSCLC patients who failed EGFR-TKIs treatment can tolerate adverse reactions related to immunotherapy combined with chemotherapy and bevacizumab treatment. PFS is significantly prolonged in those aged≤65 years and those with moderate and high expression of PD-L1.

RETRACTED: The heterogeneity of PD-L1 protein in gastric cancer: expression and distribution characteristics

Programmed death receptor ligand 1 (PD-L1) is expressed at different levels in tumour tissues and tumour-infiltrating monocytes (TIMCs). The interpretation of PD-L1 expression in gastric cancer (GC) is more difficult because of its heterogeneity. The PD-L1 immunohistochemistry (IHC) by E1L3N assay was performed in GC tissues. The level and distributed characteristics of PD-L1 expression were observed to illustrate its heterogeneity both in the cancer tissues and TIMCs. The relationship between PD-L1 level and necrotic features of tumor cells, the number of TIMCs, the distribution of tertiary lymphoid tissue (TLS) in the stroma, and other clinicopathological factors were analysed. A Cox regression model was used to assess the prognostic value of PD-L1 expression. Of the 110 GC samples, not only more cases (51/110 cases) could be detected by combined positive score (CPS) for PD-L1 expression compared the other two, tumour positive score (TPS), and mononuclear immune-cell density score (MIDS), but also there were more cases with the high level of PD-L1 expression by CPS, even if with good consistency among them (P < 0.05). The tumour cells with high expression of PD-L1 was prone to show a diffuse distributing, whereas mottled type in the low level. It was noteworthy that the strongly colored tumor cells tended to exhibit a mossy pattern which were distributed along the border between cancer nests and stroma, and the same pattern happened to occur in the positive mesenchymal cells contacting the tumor border, essentially lymphocytes and macrophages. The substantial necrosis in the tumour and the number of TIMCs was analyzed statistically significant correlated with CPS (P < 0.05), while other clinicopathological factors such as histological type, tumour size, invasion depth, TNM stage were uncorrelated. The number and distribution of TLS in the tumour and para-tumoural stroma indirectly affected PD-L1 in GC by associating with the quantity and pattern of TIMCs. Cox regression analysis revealed that the prognosis was poor when PD-L1 was positive. CPS is the best indicator for PD-L1 expression in GC, which tend to be increased expression following a large number of TIMCs and substantial tumour necrosis appeared. Heterogeneity was reflected in the different distributed pattern of PD-L1 expression, especially the mossy-like pantten of the staining tumor cell in the interface between tumour nests and stroma, regardless of the amount and intensity of PD-L1 expression. TLS is valuable for observing microscopic images to influence the quantity and pattern of TIMCs. CPS can be used as an independent prognostic factor for GC.

Molecular and clinicopathological analysis revealed an immuno-checkpoint inhibitor as a potential therapeutic target in a subset of high-grade myxofibrosarcoma.

This study aimed to identify differences in genetic alterations between low- and high-grade lesions in myxofibrosarcoma (MFS) and to examine the efficacy of immune checkpoint inhibitors in 45 patients with MFS. First, genetic differences between low- and high-grade components within the same tumor were analyzed in 11 cases using next-generation sequencing. Based on the obtained data, Sanger sequencing was performed for TP53 mutations in the remaining 34 patients. Loss of heterozygosity (LOH) analysis was performed at the TP53 and RB1 loci. Immunohistochemistry was performed for FGFR3, KIT, MET, programmed death receptor ligand 1 (PD-L1), CD8, FOXP3, and mismatch repair proteins. The microsatellite instability status was also evaluated in all cases. TP53 deleterious mutations and LOH at TP53 and RB1 loci were detected significantly more frequently in high-grade than in low-grade MFS (P = 0.0423, 0.0455, and 0.0455, respectively). LOH at the RB1 locus was significantly associated with shorter recurrence-free survival in both univariate and multivariate analyses. TP53 alterations, such as mutation and LOH, were more frequently observed in low-grade areas within high-grade MFS than in pure low-grade MFS. The positive PD-L1 expression rate was 35.6% (16/45), and all these 16 cases were high-grade. A high density of both CD8+ and FOXP3+ tumor-infiltrating lymphocytes was associated with PD-L1 positivity. LOH at the RB1 locus was identified an independent adverse prognostic factor for recurrence-free survival in patients with MFS. Immune checkpoint inhibitors may be a therapeutic option for a subset of high-grade MFS.

Correlation of PD-L1 expression with toxicities and response in oropharyngeal cancers treated with definitive chemoradiotherapy.

The programmed death receptor ligand 1 (PD-L1) is a cell-surface glycoprotein expressed in tumour cells (TCs) and is also upregulated in tumour infiltrating lymphocytes. The effect of PD-L1 expression on TCs and tumour-infiltrating lymphocytes (TILs) on acute radiation toxicity and response in oropharyngeal squamous cell carcinoma treated with concurrent chemoradiotherapy is less known. Squamous cell carcinoma of oropharynx with stage II-IVA (AJCC 8th) were recruited in this prospective observational study. Definitive radiation therapy (RT) of 70 Gray in 35 fractions at 2 Gray per fraction, 5 fractions a week in 2 phases was delivered with concurrent chemotherapy (cisplatin 40 mg/m2 weekly). Patients were assessed weekly for acute toxicities with Radiation Therapy Oncology Group criteria. Response assessment was done at 3 months post RT according to World Health Organization response assessment criteria. The programmed death receptor ligand 1 expression in TCs and TILs was correlated with acute toxicity and survival. Of 51 patients, 20 (39.2%) had PD-L1 expression in TCs and 18 (35.3%) in TILs. Patients with PD-L1 expression in TCs had fewer grade ≥ 3 oral mucositis (25% vs. 58%; p = 0.02) and grade ≥ 3 dysphagia (25% vs. 55%; p = 0.046). The programmed death receptor ligand 1-tumour infiltrating lymphocytes positives had lower ≥ 3 grade oral mucositis (22% vs. 58%; p = 0.02) and ≥ 3 grade dysphagia (17% vs. 58%; p = 0.007). Two-year overall and progression-free survival rate for the PD-L1-tumour-positive vs. PD-L1-tumour-negative group was not different (p > 0.5). Positive PD-L1 expression is associated with fewer acute radiation toxicities, and this could be used as a potential biomarker.

Overexpression of DAPK1-mediated inhibition of IKKβ/CSN5/PD-L1 axis enhances natural killer cell killing ability and inhibits tumor immune evasion in gastric cancer

Gastric cancer (GC) originates from the stomach and is a prevalent human malignancy. Dysfunction of death associated protein kinase 1 (DAPK1) has been identified as a major regulator involved in the development and progression of GC. However, there’s limited data regarding the regulatory mechanism of GC. Herein, we investigated role of DAPK1 in natural killer (NK) cell killing ability and immune evasion of GC cells and mediated pathway. Samples from GC-related gene expression profile and clinical samples from 67 patients with GC were collected to determine the expression of DAPK1, IκB kinase β (IKKβ), programmed death receptor-ligand 1 (PD-L1), and photomorphogenesis 9 (COP9) signalosome 5 (CSN5). The binding affinity among DAPK1, IKKβ, CSN5, and PD-L1 was characterized to verify the underlying mechanism. GC lines were transfected with overexpressed plasmid or siRNA to determine the effect of DAPK1/IKKβ/CSN5/PD-L1 axis on NK cell killing ability and immune evasion of GC cells. GC cells and tissues presented low expression of DAPK1 and high expression of IKKβ, CSN5 and PD-L1. IKKβ, negatively regulated by DAPK1, was capable of activating CSN5 and upregulating PD-L1 expression. Overexpression of DAPK1 promoted NK cell killing ability and reduced immune evasion, coupled with reduction of NK cell apoptosis and increases in levels of TNF-α, IFN-γ, CD107a, and Granzyme B cytokines. The tumor-suppressing properties of DAPK1 through downregulation of IKKβ/CSN5/PD-L1 axis in GC were further confirmed in vivo. In summary, overexpression of DAPK1 promoted the NK cell killing ability and restrained immune evasion of GC cells, providing a potential therapeutic strategy for GC treatment by modulating immune evasion.

PD-L1 heterogeneity in patients with non-small cell lung cancer.

Programmed death receptor ligand-1 (PD-L1) expression has been identified as the main predictor of responsiveness to programmed death receptor-1 (PD-1)-targeted immunotherapy in patients with advanced non-small cell lung cancer (NSCLC). In this retrospective study, we explored the inter- and intratumoral PD-L1 heterogeneity in patients who received two separate pathologically verified NSCLC diagnoses at Shandong Provincial Hospital Affiliated to Shandong First Medical University and Linyi People's Hospital. Patients were classified into four groups according to the type of intra- and intertumoral heterogeneity: Group 1 included patients in whom primary tumor heterogeneity was observed between biopsy and surgical specimens; in Group 2, heterogeneity was observed between primary tumors and paired dissected regional lymph nodes; in Group 3, heterogeneity was observed between resected primary tumors and distant metastases or recurrent disease; in Group 4, heterogeneity was observed before and after microwave ablation. Of the 221 enrolled patients, 97, 36, 57, and 31 were allocated to groups 1, 2, 3, and 4, respectively. Significant heterogeneity was observed among all patients (P=0.026) and within Group 1 (P=0.022) when using a PD-L1 tumor proportion score (TPS) cut-off of 5%. However, no heterogeneity was observed in the other groups or with a PD-L1 TPS cut-off value of 1%. Intratumoral PD-L1 expression heterogeneity between the biopsy and surgical specimens of primary tumors was more frequently detected than intertumoral heterogeneity in advanced NSCLC.

Correlation Study on Expression of PD-1 and PD-L1 in Non-small Cell Lung Cancer and Epidermal Growth Factor Receptor Mutations

背景与目的肺癌的治疗模式以表皮生长因子受体酪氨酸激酶抑制剂（epidermal growth factor receptor-tyrosine kinase inhibitors, EGFR-TKIs）作为EGFR突变的非小细胞肺癌（non-small cell lung cancer, NSCLC）患者一线治疗；同时以程序性死亡受体1（programmed death receptor 1, PD-1）及其配体（programmed death receptor ligand 1, PD-L1）抑制剂为代表的免疫检查点抑制剂（immune checkpoint inhibitors, ICIs）的免疫治疗在肺癌治疗中疗效显著。本研究旨在探讨PD-1和PD-L1在NSCLC中的表达及其与临床病理特征、EGFR突变之间的关系。方法采用免疫组化方法检测127例NSCLC PD-1和PD-L1蛋白表达，同时用定量聚合酶链反应（quantitative polymerase chain reaction, qPCR）检测EGFR基因突变，分析其与临床病理特征之间的关系，研究PD-1、PD-L1表达之间以及其与EGFR突变的关系。结果NSCLC肿瘤细胞及肿瘤浸润免疫细胞PD-1阳性表达53.5%（68/127），肿瘤细胞PD-L1表达57.5%（73/127），PD-1和PD-L1的表达在低分化癌、临床分期Ⅰ期+Ⅱ期明显高于高中分化癌、Ⅲ期+Ⅳ期（均P < 0.05）；EGFR突变率为46.5%（59/127），EGFR突变的患者中女性、无吸烟史、腺癌、高中分化组分别高于男性、吸烟史、鳞癌、低分化组患者（均P < 0.05）；NSCLC患者PD-L1与PD-1蛋白表达存在一致性（kappa=0.107, 5, P=0.487），EGFR突变与PD-1、PD-L1表达存在负相关关系（Φ=-0.209，Φ=-0.221，均P < 0.05）；对NSCLC患者随访，在 < 65岁、腺癌、高中分化癌、PD-L1表达的患者中位总生存期分别高于≥65岁、鳞癌、低分化癌、PD-L1不表达患者（均P < 0.05）。PD-L1低表达患者中位生存期明显高于高表达患者（P=0.04）。结论参照《非小细胞肺癌PD-L1免疫组织化学检测规范中国专家共识》检测非小细胞肺癌PD-L1表达，筛选出抗PD-1/PD-L1治疗的优势人群；同时检测出EGFR突变的患者，并且EGFR突变与PD-1、PD-L1表达存在负相关关系，依据PD-L1表达和EGFR突变状态，可能使NSCLC患者在的个体化治疗中获益，同时65岁以下、腺癌、高中分化、PD-L1低表达的患者有相对好的预后，为NSCLC预后评估提供参考。

Predictive biomarkers of inhibitors immune checkpoints therapy in malignant tumors

Immune checkpoint inhibitors (ICT) therapy is a successful immunotherapy (IT) strategy that is quite effective in a number of patients with non-small cell lung cancer, melanoma, bladder cancer, breast cancer and others. Nevertheless, there is a need in predictive markers for ICT therapy for personalized IT as far as there is a large group of patients, the proportion of which varies depending on the tumor, who do not have a clinical response to such therapy. The review summarizes the theoretical aspects and results of clinical trials dedicated to various clinical efficiency predictor using modern databases. As a result of the analysis it is established that the main candidates for the role of such markers are tumor infiltrating lymphocytes and their subpopulations, peripheral blood lymphocytes (PBL) and their subpopulations. PD1 (programmed death receptor 1) and PDL1 (programmed death receptor ligand 1) expression in tumor tissue can also be important for predicting IT efficiency. The most promising predictive biomarker meaning the most clinically relevant is a combination of the PBL subpopulations study and PD1 and PDL1 expression on the tumor cells.PubMed, Scopus, Web of Science, eLibrary, Russian Science Citation Index databases were searched for the available appropriate literature reports. The authors included 82 in the given review.

WDR5-H3K4me3 epigenetic axis regulates OPN expression to compensate PD-L1 function to promote pancreatic cancer immune escape

BackgroundDespite PD-L1 (Programmed death receptor ligand-1) expression on tumor cells and cytotoxic T lymphocytes tumor infiltration in the tumor microenvironment, human pancreatic cancer stands out as one of the human...

Histopathological Subtypes and PD-L1 Expression in Primary Urethral Adenocarcinoma: A Series of 5 Cases

Urethral adenocarcinoma is a rare disease with poor prognosis that can display multiple histologic patterns and has an unclear histogenesis. Radical surgery with extensive periurethral resection is the preferred therapeutic approach. Both chemotherapy and radiotherapy have been used as complementary treatment options. Due to the tendency of these tumors to recur, treatment-associated complications, and the limited choice of therapeutic options, patient management can be difficult. Given the lack of literature regarding immunotherapy in urethral adenocarcinoma, our objective was to explore the expression of programmed death receptor-ligand 1 (PD-L1) throughout the different histological subtypes of primary urethral adenocarcinoma. We reviewed all primary urethral adenocarcinomas diagnosed at our hospital between 1965 and 2019, performed immunohistochemical assays on the tissue blocks, classified them according to their histology and origin, and performed PD-L1 (22C3) immunohistochemistry assays in all cases. We found a total of 5 cases of primary urethral adenocarcinoma. All of the patients were women. One of the cases was a cribriform adenocarcinoma, 2 were columnar-mucinous adenocarcinomas, and 2 were clear cell adenocarcinomas. One of the clear cell adenocarcinomas strongly expressed PD-L1. In addition, a profuse inflammatory infiltration constituted by CD3-positive and CD8-positive T lymphocytes within tumor cells was observed in this case. None of the other cases showed PD-L1 expression. In conclusion, some urethral adenocarcinomas may strongly express PD-L1 and thus could potentially allow the use of immunotherapy in selected cases of advanced or recurrent adenocarcinoma.

Glucose metabolism involved in PD-L1-mediated immune escape in the malignant kidney tumour microenvironment

Programmed death receptor-ligand 1 (PD-L1) plays a crucial role in immune evasion by tumour cells. Most tumour cells exhibit energy dependency and acquire energy from glycolysis. However, the relationship between glucose metabolism and PD-L1 expression remains unclear. In this study, changes in PD-L1 expression in renal carcinoma cells were evaluated during glucose deficiency and recovery, and PD-L1 could inversely regulate glycolysis. In addition, the possible signalling pathways activated by a low level of glucose to regulate PD-L1 were tested experimentally. The results showed that glucose deficiency could upregulate PD-L1 expression in two renal cancer cell lines, 786-O and OS-RC-2. Although the native levels of PD-L1 differed in the two cell lines, the upregulated PD-L1 expression was repristinated after glucose recovery. Moreover, epidermal growth factor receptor (EGFR) expression was upregulated in both cell lines with glucose deficiency. The use of an EGFR inhibitor reversed the upregulation of PD-L1 expression induced by glucose deficiency and inhibited the phosphorylation of extracellular regulated protein kinases 1 and 2 (ERK1/2). EGFR activated by epidermal growth factor (EGF) induced PD-L1 expression and ERK1/2 phosphorylation. Furthermore, an ERK1/2 inhibitor inhibited the phosphorylation of c-Jun and decreased the elevated PD-L1 expression induced by glucose deficiency. In addition, this study also showed that 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFK-2/FBPase 3 or PFKFB3) mediated upregulation of the level of glycolysis to improve the adverse environment through PD-L1 induction. Therefore, glucose metabolism can regulate the expression of PD-L1 through the EGFR/ERK/c-Jun pathway in renal cancer, and elevated PD-L1 can also regulate glycolysis by improving the expression of PFKFB3. The findings of this study could provide a new multiple target treatment for renal cell carcinoma (RCC) therapy.

Research on the effect of PD-L1 overexpression on CLL-1 CAR-T anti-acute myeloid leukemia

目的探讨程序性死亡受体配体1（PD-L1）对CLL-1 CAR-T细胞抗急性髓系白血病（AML）作用的影响。方法通过构建PD-L1表达载体、制备慢病毒、转导、单克隆筛选技术获得稳定表达PD-L1的THP-1单克隆细胞株（THP1-PDL1），然后以前期制备的CLL-1 CAR-T细胞为效应细胞，以THP-1、THP1-PDL1单克隆细胞株作为靶细胞，分别通过LDH检测、CBA法、CFSE法评价PD-L1过表达对CLL-1 CAR-T细胞裂解功能、炎性因子释放、细胞增殖等功能的影响。结果①成功制备了PD-L1慢病毒，并筛选获得了稳定表达PD-L1的THP1-PDL1单克隆细胞株，流式细胞术及PCR验证成功。②PD-L1过表达抑制了CLL-1 CAR-T细胞裂解THP-1细胞的能力；效靶比为10∶1时，CLL-1CAR-T细胞对THP1-PDL1细胞的杀伤效率明显低于对THP-1细胞的杀伤效率［（15.70±9.90）％对（51.95±2.52）％，P<0.05］。③PD-L1过表达减弱了CLL-1 CAR-T细胞释放细胞因子的能力［与THP1-PDL1细胞共培养时对与THP-1细胞共培养时：IFN-γ（115.66±3.13）pg/ml对（1708.16±26.76）pg/ml，P<0.05；IL-6（17.37±0.72）pg/ml对（124.92±4.26）pg/ml，P<0.05；IL-10（5.69±0.13）pg/ml对（124.12±3.02）pg/ml，P<0.05］；同时抑制了CLL-1 CAR-T细胞的增殖能力。结论成功构建了表达PD-L1的THP1-PDL1单克隆细胞株，同时证实了PD-L1过表达对CLL-1 CAR-T细胞抗AML的不利的影响，为通过PD-1/PD-L1通路调控CLL-1 CAR-T细胞功能提供了一定的理论基础。

PD-L1 Expression in Small Cell and Large Cell Neuroendocrine Carcinomas of Lung: an Immunohistochemical Study with Review of Literature.

High-grade neuroendocrine tumors (HGNET) have distinctive tumor biology/behaviour. Newer modalities of treatment (immunotherapy) for them have been included in recent NCCN guidelines. Detection of programmed death receptor-ligand 1 (PD-L1) expression by immunohistochemistry have made easy identification of patients eligible for immunotherapy. We aimed to ascertain expression of PD-L1 on small cell and large cell neuroendocrine carcinomas of lung and review existing literature. Eighty-five cases of HGNET lung (primary/metastatic), were retrieved and reviewed. Immunostaining for PD-L1 using clone SP263 was done. Any amount/intensity of membranous staining of > = 1% tumor cells was cut-off for positivity. Previously published studies using Google and/Pubmed search engines were reviewed. Of 85 cases, 70 were small-cell lung cancer (SCLC), 11 large-cell neuroendocrine carcinoma (LCNEC) and 4 combined SCLC. Median age was 46.5 years with male preponderance. No PD-L1 expression was seen in 91.6% cases. The 7 positive cases were 4 LCNEC, 2 SCLC and 1 combined SCLC. The percentage positivity varied from 1-100%; lower percentage positivity was seen in SCLC. PD-L1 expression on immune cells was seen in 31.3% cases. Sixteen studies evaluating 1992 NET were found; E1L3N PD-L1 clone was commonly used clone. PD-L1 positivity was associated with better prognosis in most studies. There are only a few studies available in literature related to PDL1 expression in high grade neuroendocrine carcinomas of lung. In general, PD-L1 positivity is highly variable and seen in lower percentage of these tumors. With the recent approval of immunotherapy, biomarkers other than PD-L1 should also be investigated in these tumors.

Abstract B27: Longitudinal evaluation of PD-L1 expression on circulating tumor cells (CTCs) in non-small cell lung cancer (NSCLC) patients treated with nivolumab

Abstract Purpose: Though programmed death receptor-ligand 1 (PD-L1) expression on tumor tissue is a validated predictive biomarker for PD-1 pathway blockade in NSCLC, its longitudinal change during the treatment remains elusive. We have previously reported that PD-L1-positive rate on CTCs at baseline was correlated with response to nivolumab. Here, we conducted a longitudinal investigation of PD-L1 expression on CTCs in NSCLC patients treated with nivolumab and its association with clinical outcome. Methods: For CTC detection, 3mL of peripheral blood was collected from advanced NSCLC patients treated with nivolumab at baseline and week 4, 8, 12, and 24 or until progressive disease (PD). The samples were enriched using the microcavity array system based on the difference in size. CTCs were defined as DAPI-positive, CK-positive, and CD45-negative cells and evaluated for PD-L1 expression by additional immunostaining. Results: Forty-five patients were enrolled between January 2016 and January 2018 at Wakayama Medical University. The patient characteristics were as follows: median age 68 years (range, 49-86); male 75%; stage III/IV, 25/75%; adenocarcinoma/ squamous cell carcinoma/other, 68/25/7%; partial response/stable disease/PD/not evaluable, 20/25/45/9%. At baseline, CTCs were evaluated in 44 patients (median, 13; range, 1-104) and PD-L1 positive CTCs were detected in 82% of patients (median 29%; range, 0-100%); at week 4, evaluated in 31 patients (median, 4; range, 0-115) and detected in 58% of patients (median, 13%; range, 0-100%); at week 8, evaluated in 16 patients (median, 11; range, 1-276) and detected in 56% of patients (median, 7%; range, 0-60%); at week 12, evaluated in 13 patients (median, 11; range, 0-449) and detected in 62% of patients (median, 15%; range, 0-88%); and at week 24, evaluated in 11 patients (median, 8; range, 0-35) and detected in 55% of patients (median, 26%; range, 0-92%). Cutoff value of PD-L1-positivity rates in CTCs to segregate durable clinical benefit (DCB) from non-DCB was calculated to be 7% at week 8 according to receiver operating characteristic curve. Progression-free survival was significantly longer in the patients with less than 7% of PD-L1 positivity rates (n = 8) than in those with 7% or more (n = 8) (p &amp;lt; 0.01) at week 8, suggesting the predictive significance of early evaluation of PD-L1 expression on CTCs after nivolumab treatment. It, however, did not translate into the predictive significance in overall survival. The change in CTC count at PD did not significantly differ between PD and last evaluation point before PD compared to that in non-PD patients at each evaluation point, suggesting the change in CTC count may not be predictive of disease progression upon nivolumab treatment. Conclusion: Longitudinal evaluation of PD-L1-expressing CTCs may have a predictive potential in NSCLC patients treated with nivolumab. Evaluation in a larger cohort is warranted to confirm the results. Citation Format: Mio Ikeda, Yasuhiro Koh, Shunsuke Teraoka, Koichi Sato, Nahomi Tokudome, Atsushi Hayata, Hiroaki Akamatsu, Yuichi Ozawa, Keiichiro Akamatsu, Katsuya Endo, Masayuki Higuchi, Masanori Nakanishi, Hiroki Ueda, Nobuyuki Yamamoto. Longitudinal evaluation of PD-L1 expression on circulating tumor cells (CTCs) in non-small cell lung cancer (NSCLC) patients treated with nivolumab [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B27.

Programmed Death Receptor Ligand One Expression May Independently Predict Survival in Patients With Non-Small Cell Lung Carcinoma Brain Metastases Receiving Immunotherapy

Programmed death receptor ligand 1 (PD-L1) expression is known to predict response to PD-1/PD-L1 inhibitors in non-small cell lung cancer (NSCLC). However, the predictive role of this biomarker in brain metastases (BMs) is unknown. The aim of this study was to assess whether PD-L1 expression predicts survival in patients with NSCLC BMs treated with PD-1/PD-L1 inhibitors, after adjusting for established prognostic models. In this multi-institutional retrospective cohort study, we identified patients with NSCLC-BM treated with PD-1/PD-L1 inhibitors after local BM treatment (radiation therapy or neurosurgery) but before intracranial progression. Cox proportional hazards models were used to assess the predictive value of PD-L1 expression for overall survival (OS) and intracranial progression-free survival (IC-PFS). Forty-eight patients with BM with available PD-L1 expression were identified. PD-L1 expression was positive in 33 patients (69%). Median survival was 26 months. In univariable analysis, PD-L1 predicted favorable OS (hazard ratio [HR], 0.44; 95% confidence interval [CI], 0.19-1.02; P = .055). This effect persisted after correcting for lung-graded prognostic assessment and other identified potential confounders (HR, 0.24; 95% CI, 0.10-0.61; P = .002). Moreover, when modeled as a continuous variable, there appeared to be a proportional relationship between percentage of PD-L1 expression and survival (HR, 0.86 per 10% expression; 95% CI, 0.77-0.98; P = .02). In contrast, PD-L1 expression did not predict IC-PFS in uni- or multivariable analysis (adjusted HR, 0.54; 95% CI, 0.26-1.14; P = .11). In patients with NSCLC-BMs treated with PD-1/PD-L1 checkpoint inhibitors and local treatment, PD-L1 expression may predict OS independent of lung-graded prognostic assessment. IC-PFS did not show association with PD-L1 expression, although the present analysis may lack power to assess this. Larger studies are required to validate these findings.

PD1 and PD-L1 Inhibitors for the Treatment of Kidney Cancer: The Role of PD-L1 Assay.

Immune checkpoint inhibitors targeting the programmed death receptor ligand 1 (PD-L1)/programmed death receptor 1 (PD-1) pathway represent a drastic change in the treatment landscape of RCC resulting in a dynamic and evolving scenario. There is an urgent need for predictive biomarkers of response to provide a personalized therapeutic strategy for individual patients. In this review, we focused on trials that investigated the administration of a PD-1 and PDL1 inhibitor alone or in combination with another agent and compared the different assays applied in each trial to evaluate the role of PD-L1 as a prognostic and predictive biomarker. So far, the use of PD-L1 expression alone is not sufficient to predict treatment response and present many limitations: the lack of consensus between different methodologies on biomarker assessment, the heterogeneity of PD-L1 between primary tumors and metastatic sites, different criteria of response to therapy (RECIST vs. irRECIST), the complex interplay with inflammatory components, previous treatments, administration of antibiotic therapy. Combinations of different biomarkers and biological features, such as gene expression associated with angiogenesis, immune response and myeloid inflammation are promising biological variables that need to be validated in the context of prospective clinical trials.

Relationship Between Programmed Death Receptor-Ligand 1 Expression and Response to Checkpoint Inhibitor Immunotherapy in Pulmonary Sarcomatoid Carcinoma: A Pooled Analysis

BackgroundPulmonary sarcomatoid carcinoma (PSC) or pleomorphic carcinoma is a rare subtype of non-small cell lung cancer. Some reports have suggested the efficacy of checkpoint inhibitor immunotherapy for PSC. However, owing to the small number of patients in each report, it remains unclear whether programmed death receptor-ligand 1 (PD-L1) expression is predictive of tumor response or survival. Patients and MethodsThe English literature was systematically searched for articles published from 2015 to 2019 and reported on tumor response or progression-free survival (PFS) after immunotherapy for advanced PSC. In addition, our institutional electronic medical records were searched for eligible cases to be included. Pooled analyses were performed. ResultsAnalyses included 90 patients. Best tumor response was partial or complete response in 54.5%, stable disease 15.9%, and progressive disease in 29.6%. The median PFS was 7.0 months. Among 66 patients with reported PD-L1 expression, the level was <1% in 7 patients (10.6%), 1%-49% in 10 patients (15.2%), and ≥50% in 49 patients (74.2%). A positive relationship between PD-L1 level and tumor response was observed. Among 47 patients with a PD-L1 of ≥50%, 33 patients (70.2%) achieved response, compared with 5 of 10 patients (50%) with a PD-L1 of 1%-49% and 2 of 7 patients (28.6%) with a PD-L1 of <1% (P = .026). PFS was superior among patients with a PD-L1 of ≥1% compared with those with a PD-L1 of <1% (14.4 months vs. 2.7 months respectively; P = .04). ConclusionsAmong patients with advanced PSC, PD-L1 expression is significantly associated with increased tumor responses and improved PFS after checkpoint inhibitor immunotherapy.

High PD-L1 expression in gastric cancer (GC) patients and correlation with molecular features

BackgroundThe programmed death receptor ligand 1 (PD-L1) immunohistochemistry (IHC) 22C3 pharmDx assay is a widely used selection method for pembrolizumab treatment in gastric cancer (GC) patients, especially in the U.S. The present study investigated the relationship between PD-L1 expression and the clinical features, molecular markers, and molecular subtypes of GC. MethodsPD-L1 expression was assessed based on combined positive score (CPS) using PD-L1 IHC 22C3 pharmDx in the Asian Cancer Research Group (ACRG) GC cohort (N = 300), which has been previously genomically profiled. PD-L1 positivity was defined as PD-L1 CPS ≥ 1. The association between PD-L1 expression and clinical features, tumor burden, and molecular subtypes (ACRG and The Cancer Genome Atlas [TCGA]) was analyzed. ResultsOf the 300 tumors, 178 (59.3 %) had PD-L1 CPS ≥ 1 and 122 (40.7 %) had PD-L1 CPS < 1. PD-L1 CPS ≥ 1 was significantly associated with stage I tumor (P = 0.022), high microsatellite instability (MSI-H) (P < 0.001), Epstein-Barr virus (EBV) positivity (P = 0.008), and positive Helicobacter pylori status (P = 0.001). PD-L1 CPS ≥ 1 was observed in 96/193 (49.7 %) EBV-negative/microsatellite stable (MSS) tumors. In gene expression profiling, PD-L1 CPS was highly correlated with mutational load (P < 0.001) as well as EBV (P < 0.001) and MSI subtypes (P < 0.001); 27/300 (9%) GC patients had a very high PD-L1 (≥ 20) score (MSI-H, n = 10; EBV, n = 6; and non-EBV/MSS, n = 11). OS was longer in patients with PD-L1 CPS ≥ 1 tumors than in those with PD-L1 CPS < 1 tumors (median OS not reached vs. 40 months; P = 0.008; log-rank test). ConclusionsPD-L1 is expressed in 59.3 % of GC patients and is associated with MSI and EBV positivity. These results provide a basis for identifying GC patients who may benefit from anti-PD-1/PD-L1 therapy.

PD-L1 expression and deficient mismatch repair in ductal adenocarcinoma of the prostate.

This study aimed to investigate the expression of programmed death receptor ligand 1 (PD-L1) and deficient mismatch repair (dMMR) in ductal adenocarcinoma of the prostate. A tissue microarray of 32 ductal and 42 grade-matched acinar adenocarcinomas was used. Slides were stained for PD-L1, PD-L2, MMR proteins, CD4 and CD8. PD-L1 expression in tumor cells was only seen in 3% (1/34) of ductal and 5% (2/42) of acinar adenocarcinomas (p=1.0), while PD-L1 expression in tumor-infiltrating immune cells was seen in 29% (10/34) of ductal and 14% (6/42) of acinar adenocarcinomas (p=0.16). dMMR, as defined by loss of one or more of the MMR proteins, was identified in 5% (4/73) of cases, including 1 ductal and 3 acinar adenocarcinomas. There was a suggested association between infiltration of CD8+ lymphocytes and ductal subtype (p=0.04) but not between CD4+ lymphocytes and tumor type (p=0.28). The study shows that both dMMR and PD-L1 expression is uncommon in tumor cells of both ductal and acinar adenocarcinoma of the prostate, while PD-L1 expression in tumor-infiltrating immune cells is a more common finding.