Negative PD-L1 Expression Research Articles

Prognostic value of proliferation, PD-L1 and nuclear size in patients with superior sulcus tumours treated with chemoradiotherapy and surgery

AimsThe aim of this study was to determine the relationship between proliferative activity, PD-L1 status and nuclear size changes after preoperative chemoradiotherapy (CRT) and the clinical outcome in patients with...

Prevalence and Prognostic Implications of PD-L1 Expression in Soft Tissue Sarcomas.

Background: PD-L1 expression differs from 19 to 92% in various cancer subtypes. Its expression carries a worse prognostic value in various malignancies and could also be used as a predictive marker for immune checkpoint inhibitor response. This study aimed to explore the prevalence of PD-L1 expression in soft tissue sarcomas and the correlation of PD-L1 expression with clinicopathological features. Patients and Methods: The tissue samples of 50 patients with STS were tested for PD-L1 expression using immunohistochemistry (IHC). We followed a 6-step proportional scoring system. The patients were treated at Ain Shams University Hospital from 2011 to 2017. We also explored the correlation of PD-L1 expression with different clinical features of the patients. The chi-square test was used to calculate the differences among variables. Results: Twelve cases (24%) showed positive PD-L1 expression with the highest prevalence in rhabdomyosarcoma and desmoid tumors (2/2 and 2/3 cases, respectively), followed by GIST in 2/4 cases and liposarcoma in 3/11 cases. Patients with positive PD-L1 expression showed a trend for worse survival, with a median overall survival of 11 months vs. 19 months for patients with negative PD-L1 expression (p-value = 0.1) and a mean PFS of 6 months vs. 11 months for patients with negative PD-L1 expression (p-value = 0.1). However, these findings did not reach statistical significance. Conclusion: Although the results did not reach statistical significance due to the small number of cases, PD-L1 expression could represent a prognostic factor for poor outcome. Larger clinical trials are recommended for the validation of PD-L1 as a poor prognostic biomarker.

ICI plus chemotherapy prolonged survival over ICI alone in patients with previously treated advanced NSCLC.

Immune checkpoint inhibitors (ICI) monotherapy was standard of care in second-line treatment of patients with advance non-small cell lung cancer (NSCLC). This study aims to investigate the efficacy of ICI plus chemotherapy in patients with previously treated advanced NSCLC. An investigator-initiated trial (IIT) aiming to evaluate the efficacy and safety of ICI in combination with chemotherapy as second line and beyond for patients with advanced NSCLC was undergone at Shanghai Pulmonary Hospital (ChiCTR1900026203). Patients who received ICI monotherapy as second or later line setting during the same period were also collected as a comparator. From April 2018 to June 2019, 31 patients were included into this IIT study, simultaneously 51 patients treated with ICI monotherapy were selected as a comparator. ICI plus chemotherapy showed a significantly higher ORR (35.5% vs. 15.7%, p=0.039), prolonged PFS (median: 5.6 vs. 2.5 months, p = 0.013) and OS (median: NE vs. 12.6 months, p = 0.038) compared with ICI alone. In the subgroup of negative PD-L1 expression (9 patients in combination group and 12 patients in monotherapy group), ICI plus chemotherapy also had a favorable ORR (44.4% vs. 8.3%, p = 0.119), longer PFS (median: 6.5 vs 3.0 months, p < 0.05) and OS (median: NE vs. 8.2 months, p = 0.117). Meanwhile, the addition of chemotherapy did not increase immune-related adverse events. ICI plus chemotherapy showed superior ORR, PFS and OS than ICI alone patients with previous treated advanced NSCLC. These findings warrant further investigation.

Clinical significance of next-generation sequencing in Chinese patients with relapsed/refractory Wilm’s tumor.

e22003 Background: Medical advances have been greatly improved in the survival rate for Wilms’ tumor, but the survival is still dismal for relapsed/refractory (R/R) patients. In the present study, we aimed to investigated the genomic profiling and the incidence of germline cancer susceptibility mutations of Chinese patients with R/R WT. Methods: From Jun 18, 2020 to Dec 22, 2020, the tumor specimens with matched blood samples obtained from R/R pediatric WT in Sun Yat-Sen University Cancer Center were performed next-generation sequencing (NGS) using a 539 cancer-related gene panel in a CAP-certified laboratory (Simcere Diagnostic Co, Ltd). Clinical information including age, gender and tumor histology were collected. Somatic and germline variations including single nucleotide variants (SNV), insertion-deletion variants (Indels), copy number variations (CNVs) and fusion, as well as tumor mutational burden (TMB)/microsatellite instability (MSI) were analyzed. IHC staining for PD-L1 expression was performed by FDA-approved VENTANA PD-L1(SP263) assay. Results: Eight patients with R/R WT were enrolled in this study, including 5 males and 3 females, with a median age of 6 years old (range, 3-14). All of the pathology was identified as favorable histology WT (FHWT). Of the specimens, 8 were from pulmonary and 1from peritoneum. We identified 152 reportable molecular aberrations, with a median of 19 (0-24). CNVs accounted for the majority of the total somatic aberrations, followed by SNVs, the percentage was 77% and 22%, respectively. Genes with either CNVs or SNVs were detected in FGFR1 (n=4), ERBB2(n=3), MYCN(n=4), MET(n=2), CDK4/6(n=2), TP53(n=2), CTNNB1(n=2), MYC(n=2), NF1(n=2), MDM4(n=2), CHEK2(n=1), FBXW7(n=1), EGFR(n=1). Notable cancer driver mutations were also characterized, such as the amplifications of ERBB2/MET/EGFR/FGFR1, and the point variations of CHEK2/FBXW7/NF1. Besides, a novel ASB12 intergenic region- AMER1 fusion was identified. Both of the patients available for PD-L1 evaluation showed negative PD-L1 expression on tumor cells. The median TMB was 1.47 (range, 0-7.8). All patients were microsatellite stabilization (MSS). A 4-year-old patient suffering peritoneal relapse harbored a germline pathogenic mutation in FANCA (c.1777-1G&gt;C, intron 19), this locus has never been reported in WT before. Conclusions: We discovered some driver genes mutations which potentially sensitive to the corresponding targeted drugs in Chinese R/R WT patients. Large sample size was needed to provide a better understanding of molecular features in R/R WT patients to achieve precision medicine.

Tumor mutational burden assessment in non-small-cell lung cancer samples: results from the TMB2 harmonization project comparing three NGS panels

BackgroundTumor mutational burden (TMB) is a recently proposed predictive biomarker for immunotherapy in solid tumors, including non-small cell lung cancer (NSCLC). Available assays for TMB determination differ in horizontal coverage,...

Malignant pleural mesothelioma: clinical experience and prognostic value of derived neutrophil-to-lymphocyte ratio and PD-L1 expression.

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor, with a poor prognosis. MPM needs to find prognostic factors of survival. We provided the management of patients with MPM and sought to determine whether pre-treatment levels of derived neutrophil-to-lymphocyte ratio (dNLR) as well as PD-L1 expression were reliable prognostic factors of survival. We conducted a single-institution retrospective study, including all patients with MPM treated at La Paz University Hospital between December 2009 and March 2018. Baseline disease, demographics, clinical data, treatment characteristics and complete blood cell counts were collected. We examined dNLR at baseline and data for PD-L1 expression were analyzed in tumor cells by immunohistochemistry. We included 25 patients. The median overall survival (OS) was 15.7months (95% CI 11.3-20.0). 5 patients had a dNLR greater than 3 (20%). Patients with a dNLR greater than 3 had shorter median OS (8.5months), than patients with a dNLR less than 3 (17.0months), with statistically significant differences (p = 0.038). Ten patients (40%) had positive PD-L1 expression (≥ 1%). Patients with positive PD-L1 expression had shorter median OS (8.5months) than patients with negative PDL1 expression (15.7months), but without statistically significant association (p = 0.319). The survival data obtained in our sample are consistent with those previously reported. Pretreatment levels of dNLR greater than 3 and positive PD-L1 expression could be significant prognostic factors for poor survival in patients with MPM. Further and prospective studies are needed to explore this relationship and to derive definitive conclusions.

Undifferentiated colonic neoplasm with SMARCA4 germline gene mutation and loss of SMARCA4 protein expression: a case report and literature review

BackgroundNonsense mutation or inactivation of SMARCA4 (BRG1) is associated with a monomorphic undifferentiated histological appearance in tumors at different sites. The association between SMARCA4 alteration and undifferentiated colonic carcinoma needs to be further elucidated.MethodsA 61-year-old male patient presented to the hospital with intermittent epigastric pain in the right upper abdomen and abdominal distension. The enhanced computed tomography detected a mass in the hepatic flexure of the colon and multiple liver metastases.ResultsThe right hemicolectomy contained a 4.5-cm undifferentiated malignancy with cells arranged in sheets, abundant necrosis, and areas showing rhabdoid morphology. The immunohistochemistry result showed that these tumor cells were focally positive for cytokeratin (CK), CK8, and CK18; however, diffusely positive for vimentin, P53, Fli-1, and SALL-4. Notably, tumor cells showed a heterogeneous loss of SMARCA4 expression pattern and intact SMARCB1 expression. Next-generation sequencing showed a germline SMARCA4 c.3277C>T(p.R1093*)mutation, somatic APC mutation, and no abnormal SMARCB1 gene. The tumor exhibited microsatellite stability, negative PD-L1 expression, and few infiltrating CD8 + T cells. The patient died a month later after surgery.ConclusionsWe presented a rare case of undifferentiated colonic neoplasm with loss of SMARCA4 protein expression and germline SMARCA4 mutation. Moreover, the role of SMARCA4 alterations in tumor diagnosis and treatment was also summarized.

Abstract PS4-38: Association of tumor infiltrating lymphocytes (TILs) density and PD-L1 expression with pembrolizumab (P) plus gemcitabine (Gem) efficacy in patients with HER2-negative advanced breast cancer (ABC) from the GEICAM/2015-04 (PANGEA-Breast) study

Abstract Background Immune cells (ICs) infiltration and immune checkpoints have been shown to be important for BC patients’ (pts) prognosis and response to immunotherapy. We aimed to analyze the relation between TILs prevalence and PD-L1 expression with efficacy to an immunostimulatory combination with P and Gem in ABC HER2-negative pts previously treated with ≤4 chemotherapy and/or ≥2 hormone therapy lines from the PANGEA-Breast trial (NCT03025880). Methods Pre-treatment (ttm) metastatic BC samples were assessed for TILs density [% of occupied stromal area upon H&amp;E staining] and for PD-L1 immunohistochemistry expression using monoclonal anti-PD-L1 antibody clone 22C3 (Merck) by calculating ICs score (% of positive infiltrated ICs) and combined positive score [CPS; PD-L1 stained cells (tumor cells, lymphocytes, macrophages) divided by total viable tumor cells, multiplied by 100]. Cut-offs ≥5%, ≥10%, ≥30% were explored for TILs. PD-L1 scores were considered positive if ≥1%. Cut-offs (≥5%, ≥20%, ≥50%) were additionally assessed for PD-L1 as CPS. Logistic regression models were used to evaluate association between TILs density and PD-L1 expression with ttm efficacy in terms of Objective Response Rate [ORR; Complete + Partial Response (CR + PR)], Clinical Benefit Rate [CBR; CR + PR + Stable Disease ≥24 weeks] and Progression Free Survival (PFS), according to RECIST v1.1. Results Thirty-six pts were included, 58% had triple negative BC and 98% ECOG score ≤1. Median number of prior ttm lines was 4. ORR and CBR were 15.2% and 17%, respectively; median PFS was 3.1 months. TILs and PD-L1 were evaluated in 30 and 29 pts, respectively. No association was found between TILs density and ttm efficacy in terms of ORR, CBR and PFS. Analysis of PD-L1 ICs score did not reveal any significant association with ORR, CBR or PFS. However, pts with negative PD-L1 expression by CPS (&amp;lt;1%) had a significantly prolonged PFS [p-value=0.031; HR 0.39 (95%CI 0.16; 0.95)], not maintained at CPS &amp;lt;20% cut-off [p-value=0.062; HR 0.42 (95%CI 0.17; 1.08)]. Conclusions Our findings support that: 1) P plus Gem ttm in heavily pre-treated HER2-negative ABC pts obtains a modest ORR of 15.2%; 2) TILs density and PD-L1 expression in ICs does not predict its benefit; 3) PD-L1 in tumor cells scored as CPS impacts in worse outcome (PFS) but not in ORR, suggesting an eventual prognostic role in this population; 4) no long-term responders were observed with P plus Gem in this trial. Citation Format: Luis De la Cruz, María Gion, Josefina Cruz, Jose Luis Alonso, Vanesa Quiroga, Fernando Moreno, Marta Santisteban, Raquel Andrés, Esther Holgado, Natalia Palazón, Luz Milva Rodríguez, Asunción Soto, Javier Cortés, Alfonso Cortés, Manuel Ramos, Maribel Casas, Massimo Chiesa, Susana Bezares, Rosalía Caballero, Federico Rojo. Association of tumor infiltrating lymphocytes (TILs) density and PD-L1 expression with pembrolizumab (P) plus gemcitabine (Gem) efficacy in patients with HER2-negative advanced breast cancer (ABC) from the GEICAM/2015-04 (PANGEA-Breast) study [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS4-38.

PD-L1 Expression in colorectal carcinoma and its correlation with clinicopathological parameters, microsatellite instability and BRAF mutation.

: Programmed cell death ligand-1 (PD-L1) is the key inhibitor of the cytotoxic immune response thus causing progression of tumors and adverse prognosis in many malignancies. The current study investigates PD-L1 expression in colorectal carcinoma and its correlation with clinicopathological parameters, microsatellite instability, and BRAF mutation. 110 cases of colorectal carcinoma were evaluated for PD-L1 expression using SP263 clone in tissue microarray. Clinico-pathological characteristics and survival data were correlated with PD-L1 expression analyzed at different cut-offs of ≥1%, ≥10% and ≥50% in tumor cells and tumor infiltrating lymphocytes along with its correlation with BRAF expression and microsatellite instability status in these cases. Mean age was 49 years with male to female ratio of 1.5:1. 52.7% cases presented with stage 3/4 disease and 14.7% with >10 cm tumor size. Tumor cells expressed PD-L1 in 40% and TILs in 45.4% cases at a cut off of ≥1% was 17.3%, at ≥10% was 15.5% and at ≥50% was 7.3%. Significant association was seen between tumor proportion score (TPS) and increasing age, histological type, histological grade, tumor size, higher T stage (p = 0.03), TILs (p = 0.04), lymph vascular invasion, and perineural invasion. PDL-1 correlated with BRAF expression and microsatellite instability (MLH-1/PMS-2 expression loss). The overall survival was significantly higher (p < 0.001) with negative PDL1 expression in cases of colorectal carcinoma. Immunotherapy may be used as potential therapeutic option in colorectal carcinoma cases showing microsatellite instability and BRAF mutations which show poor response to conventional chemotherapy regimen and anti-EGFR therapy.

Tumor-Infiltrating Immune Cells and PD-L1 as Prognostic Biomarkers in Primary Esophageal Small Cell Carcinoma.

Primary esophageal small cell carcinoma (PESCC) is a weakly prevalent but lethal malignancy with early metastasis and a poor prognosis. Currently, neither effective prognostic indicators nor curative therapies are available for PESCC. Immunotherapy has now evolved into one of the most promising therapies for cancer patients. Tumor-infiltrating immune cells which are integral to the tumor immune microenvironment (TIME) are recognized as highly important for prognosis prediction, while the responsiveness to immune checkpoint blockade may be subject to the features of TIME. In this study, we aim to identify the TIME and provide indication for the applicability of immune checkpoint therapy in PESCC. We found that PD-L1 expression was detected in 33.33% (27/81) of all the patients, mostly exhibiting a stroma-only pattern and that it was positively associated with tumor-infiltrating immune cells (CD4+, CD8+, and CD163+). In 74.07% of PD-L1-positive specimens, PD-L1+CD163+ cells were colocalized more with CD4+ than CD8+ T cells. 83.95% (68/81) of all the specimens were infiltrated with more CD4+ than CD8+ T cells. Further analysis showed FoxP3+ Tregs constituted 13-27% of the total CD4+ T cell population. The Kaplan-–Meier analysis indicated several factors that contribute to poor survival, including negative PD-L1 expression, rich CD4 expression, rich FoxP3 expression, a low CD8/CD4 ratio, and a high FoxP3/CD8 ratio. A nomogram model was constructed and showed good performance for survival prediction. These results highlight that a suppressive TIME contributes to poor survival of patients with PESCC. TIME analyses might be a promising approach to evaluate the possibility and effect of immune checkpoint-based immunotherapeutics in PESCC patients.

Immunotherapy in advanced Non-Small Cell Lung Cancer patients with poor performance status: The role of clinical-pathological variables and inflammatory biomarkers

BackgroundThe introduction of immunotherapy has improved the prognosis of patients with Non-Small Cell Lung Cancer (NSCLC). However, data in poor ECOG Performance Status (PS) patients remain scant due to their exclusion from randomized trials. Material and methodsWe analyzed data of patients with advanced NSCLC treated with immunotherapy in two Italian Centers, to evaluate the impact of PS (0-1 vs 2) on disease control rate (DCR), progression free survival (PFS) and overall survival (OS). Chi-square test was used to compare clinical-pathological variables, their impact on survival was evaluated through Cox proportional hazard models. ResultsAmong 404 patients included, PS was 0 in 137 (33.9 %), 1 in 208 (51.5 %) and 2 in 59 (14.6 %) patients; 143 were female and 90 had squamous NSCLC. Clinical-pathological variables were uniformly distributed except for higher prevalence of liver metastases in patients with poor PS. We found that PS2 patients showed worse outcomes in terms of DCR (21.8 % vs 50.3 %, p = 0.001), PFS [2.0 (95 % CI 1.6–3.0) vs 3.0 (95 % CI 2.7–4.0) months, p < 0.0001] and OS [4.0 (95 % CI 2.8–5.7) vs 13.2 (95 % CI 11.0−15.8) months, p < 0.0001]. PS2 status, negative PDL1 expression and early corticosteroids exposure as well as higher Neutrophil to Lymphocyte Ratio and LDH at baseline were associated with worse outcomes at univariate and multivariable analysis. Subgroup analysis confirmed poor outcomes in PS2 patients with high LDH and concomitant corticosteroid therapies. The incidence of Grade 3/4 adverse events was 11.3 % in PS 0−1 and 10.2 % in PS 2 patients (p = 0.81). ConclusionOur data confirm reduced efficacy of immunotherapy in patients with poor PS even though a good safety. Despite PS remains the most powerful independent prognostic factor for NSCLC, LDH levels and steroids exposure could support the decision making in PS2 patients.

Expression of PD-L1 for predicting response to immune checkpoint inhibitors in metastatic urothelial carcinoma: a systematic review and meta-analysis.

We conducted this meta-analysis and systematic literature review to study the ability of PD-L1 to predict objective response in patients with urothelial cancer treated with PD-1/PD-L1 inhibitors. Relevant studies of PD-1 or PD-L1 inhibitors in urothelial cancer that reported objective response rate (orr) based on PD-L1 expression status in PubMed, embase, and the Cochrane Library were retrieved. Efficacy of PD-L1 expression status in predicting orr and the efficacy, safety of PD-1 and PD-L1 drugs were analyzed. Studies were divided into ≥1%, ≥5%, and ≥25% based on PD-L1 positivity threshold, and the patients were grouped into PD-L1 positive and negative. In all 3 expression thresholds, patients with positive PD-L1 expression were more likely to experience an objective response [≥1% threshold odds ratio (or): 1.74; 95% confidence interval (ci): 1.20 to 2.53; ≥5% threshold or: 2.74; 95% ci: 2.01 to 3.724; ≥25% threshold or: 7.13; 95% ci: 2.38 to 21.40] in comparison with patients with negative PD-L1 expression. Of the 3 thresholds, the ≥25% threshold was better in predicting orr (1.74 vs. 2.93 vs. 7.13; p < 0.0001). The ≥1% PD-L1 threshold had a relatively high sensitivity in predicting orr; the ≥5% PD-L1 threshold was better for specificity. Sensitivity was higher at the ≥25% threshold than at the other two thresholds, but specificity was lower. Further, we found that there is no statistically significant difference in efficacy between PD-1 and PD-L1 drugs. Urothelial cancer patients with PD-L1 positive expression responded better than PD-L1 negative patients did, and a threshold of ≥5% or greater for PD-L1 expression might predict positive clinical response.

PDL1 high expression without TP53, KEAP1 and EPHA5 mutations could better predict survival for patients with NSCLC receiving atezolizumab

BackgroundNon-small cell lung cancer (NSCLC) patients with high expression of PDL1 are more likely to benefit from atezolizumab. There are no relevant research focusing on the relationship between the PDL1 expression and clinical variables and gene mutation types among NSCLC patients. MethodsNSCLC patients with confirmed PDL1 expression and gene mutation information from OAK study were included in our study. Logistic regression proportional model was applied to analyze the risk factors on PDL1 high expression. The biomarker evaluable population (BEP) was screened to analyze the gene mutation informaion among these patients. High frequency gene mutations were screened based on different PDL1 expressions. Moreover, the log rank test was applied to analyze the overall survival (OS) difference based on different gene mutation types. ResultsA total of 838 patients with NSCLC were included in our study. White patients are more likely to have PDL1 ≥ 1% (P = 0.004). ERBB4, EP300, PREX2, SLIT2, EPHB1 and IGF2R mutations were high frequency mutations in patients with high PDL1 expression, and the patients with EGFR, SMARCA4, EPHA5, FAT1, STK11, TET2 mutations were more likely to be seen in negative PDL1 expression group. Worse survival could be found in patients with KEAP1 (P < 0.001), TP53 (P = 0.004) and EPHA5 (P = 0.013) mutations who received atezolizumab compared with those who had none of these gene mutations. Importantly, for PDL1 high patients without KEAP1, EPHA5, TP53 mutations receiving atezolizumab, they all showed relatively longer median survival with 22.47, 22.18 and 23.33 months, respectively (all, P < 0.01). ConclusionsDifferent high frequency gene mutations could be found between the patients with high and negative PDL1. PDL1 expression combined with specific gene mutation may better predict the survival for patients receiving atezolizumab.

Prognostic significance of PD-L1 in advanced non-small cell lung carcinoma.

This study aimed to investigate the prognostic value of PD-L1 in Chinese patients with non-small cell lung carcinoma (NSCLC).In this retrospective study, 97 patients with NSCLC were consecutively recruited. The expression profiling of PD-1, PD-L1, p53 and Ki-67 was detected by immunohistochemistry. Median survival time was estimated by Kaplan–Meier survival curve with log-rank test. Risk factors were evaluated by Cox Proportional Hazards regression models.The median tumor size was larger (3.5 cm) among patients with positive PD-L1 expression, compared to those with negative expression (2.0 cm; P < .01). Compared to those with negative PD-L1 expression, patients with positive PD-L1 expression had significantly higher rates of nerve invasion (26.3% vs 5.0%; P < .01), blood vessel invasion (47.4% vs 20.0%; P < .01) and lymph node metastasis (64.9% vs 27.5%; P < .01), more advanced tumor stage (P < .01) and Ki-67 index (P < .01). PD-L1 expression status was not significantly associated with disease-free (DFS) or overall survival (OS). However, for patients with advanced disease, PD-L1 positive expression was related to worse outcome (HR: 4.13; 95% CI: 1.06–16.12).Positive PD-L1 expression is associated with more aggressive pathological features and poorer prognosis in advanced stage NSCLC.

PD-L1 Expression is Highly Associated with Tumor-Associated Macrophage Infiltration in Nasopharyngeal Carcinoma.

PurposeTumour-associated macrophages (TAMs) are the most abundant immune cells in the tumor microenvironment and provide a barrier against the cytotoxic effector functions of T cells and natural killer (NK) cells. Recently, TAMs have become increasingly recognised as an attractive target in combination therapy with PD-1/PD-L1 immuno-checkpoint blockades (ICBs). However, the relationship between PD-L1 expression and TAMs remains unknown in nasopharyngeal carcinoma (NPC).Patients and MethodsA total of 212 NPC patients from Nanfang hospital were collected in this study. We evaluated the expression of PD-L1 in tumor cells, CD68 (pan-macrophages), and CD163 (M2-like macrophage) in NPC tissues using immunohistochemical (IHC) staining.ResultsThe positivity of PD-L1 on tumor cells was 61.3% (130/212). The infiltration densities of CD68+ cells and CD163+ cells in PD-L1-positive NPC tissues were significantly higher than those in PD-L1-negative NPC tissues (P=0.0012 for CD68; P<0.0001 for CD163). Logistic regression analysis showed that high densities of CD68+ macrophages and CD163+ TAMs were significantly associated with increased PD-L1 expression. Subgroup analyses demonstrated that a positive PD-L1 expression on tumor cells in combination with lower CD163+ TAMs density was significantly associated with favorable prognosis, whereas negative PD-L1 expression on tumor cells with higher CD163+ TAMs density was associated with worse prognosis.ConclusionThe PD-L1 expression in tumor cells was positively correlated with TAMs density in tumor microenvironment of NPC, suggesting TAMs as a new target for combination therapy to improve the response rate of ICBs in NPC treatment.

Predictive value of CD8/FOXP3 ratio combined with PD-L1 expression for radiosensitivity in patients with squamous cell carcinoma of the larynx receiving definitive radiation therapy.

Little is known about immune-related radiosensitivity in patients with squamous cell carcinoma of the larynx (SCC-L) treated with radiation therapy (RT). We retrospectively reviewed 91 patients with SCC-L treated with RT or chemoradiation therapy and performed immunohistochemical examination to analyze PD-L1 level on tumor cells, CD4+ tumor-infiltrating lymphocytes (TILs), CD8+ TIL, and FOXP3+ TIL using pretreated biopsy specimens. The association between these immune-related parameters and radiosensitivity was evaluated. Multivariate analyses showed that high CD8/FOXP3 ratio combined with negative PD-L1 expression was an independent and significant favorable predictive factor for local control, compared with the other groups. We showed that high CD8/FOXP3 ratio combined with negative PD-L1 expression might be a useful biomarker of radiosensitivity in patients with SCC-L receiving definitive RT. We propose that coassessment of CD8/FOXP3 ratio and PD-L1 expression level in tumor cells can help predict potential radiosensitivity in patients with SCC-L.

Abstract 3272: Is PD-L1 expression a decision-making biomarker for immunotherapy: a meta-analysis and cross-sectional study

Abstract Background: PD-L1 expression has been approved by FDA as a diagnosis for anti-PD-(L)1 therapy in several types of cancer, however, there were still discrepancies of the predictive value of PD-L1 expression. Here we aimed to systematically assess the value of PD-L1 expression in determining cancer patients who should be offered anti-PD-(L)1 therapy and to characterize PD-L1 expression in Chinese cancer population. Methods: Cochrane library, PubMed and Embase databases were systematically searched to include relevant studies published between January 2000 and June 2019. We also reviewed the reports from all major conference proceedings. All randomized controlled trials investigating anti-PD-(L)1 efficacy in solid tumors were initially included if overall survival (OS) data were stratified by PD-L1 expression. Differences in OS benefits between PD-L1-positive and PD-L1-negative patients were analyzed. Effect size derived from each study was pooled using a random-effects model. Data regarding PD-L1 expression in Chinese patients were obtained from a CAP-accredited and CLIA-certified laboratory. Results: Twenty-five RCTs involving 14,471 patients were included. OS benefit was observed in patients with either positive (HR=0.68 [0.63-0.73], P&amp;lt;0.00001) or negative (HR=0.86 [0.78-0.95], P=0.003) PD-L1 expression, though significant longer OS was achieved in patients that are PD-L1 positive (P interaction=0.0001). Superior PFS were observed in patients with positive PD-L1 expression (HR=0.69 [0.57-0.82]) while not with negative PD-L1 expression (HR=1.00 [0.85-1.19]). PD-L1-positive patients exhibited significantly improved ORR than those who tested negative for PD-L1 when treated with immunotherapy (OR=0.50 [0.39-0.65], P&amp;lt;0.00001), while no differences were observed among patients given SOC (OR=1.02 [0.86-1.21], P=0.81). Analysis of Chinese patients PD-L1 status revealed that thymoma and small cell lung cancer expressed the highest and the lowest levels of PD-L1, respectively. Conclusion: PD-L1 expression alone is not determinative in patient selection for anti-PD-(L)1 treatment. Multiple modality biomarkers should be considered for cancer patients especially for those with PD-L1-negative tumors. Citation Format: Zhijie Wang, Jianchun Duan, Longgang Cui, Shangli Cai, Jie Wang. Is PD-L1 expression a decision-making biomarker for immunotherapy: a meta-analysis and cross-sectional study [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3272.

Abstract CT191: Interim results from CLASSICAL-Lung, phase 1b/2 study of pepinemab (VX15/2503) in combination with avelumab in advanced NSCLC

Abstract Despite progress of immune checkpoint therapies, many cases of non-small cell lung cancer (NSCLC) are refractory or acquire resistance to current therapies. Antibody blockade of semaphorin 4D (SEMA4D, CD100) can overcome resistance mechanisms of immune exclusion and myeloid suppression. Importantly, combinations of anti-SEMA4D with various immunotherapies enhanced T cell infiltration and activity, leading to durable tumor regression in preclinical models. Pepinemab (VX15/2503) is a first-in-class humanized monoclonal antibody targeting SEMA4D. The CLASSICAL-Lung clinical trial tests the combination of pepinemab with avelumab to couple immune activation via checkpoint inhibition with beneficial modifications of the tumor immune microenvironment via pepinemab. Here, we present interim results of the Phase 2 portion of the CLASSICAL-Lung study. This phase 1b/2, open label, single arm, first-in-human combination study is designed to evaluate the safety, tolerability and efficacy of pepinemab in combination with avelumab in 62 subjects with advanced stage (IIIB/IV) NSCLC, including immunotherapy-naïve (ION) patients and patients whose tumors progressed during or following immunotherapy (IOF). Dose escalation was successfully completed, presented previously, and no concerning safety signals have been identified to date. Among 29 evaluable IOF patients, 2 experienced confirmed partial response (PR) with 66% and 52% tumor reduction following acquired resistance to prior treatment with pembrolizumab, 15 additional patients experienced stable disease (SD), and at least 7 patients had durable clinical benefit of ≥ 23 weeks. Among 21 evaluable ION patients, 5 experienced PR, and 3 patients had clinical benefit ≥ 1 year. The disease control rate was 81%. Analysis of pre- and on-treatment biopsies demonstrated increased CD8+ T cell density correlating with response, with reduction or elimination of tumor in 10/11 biopsies from subjects with PR or SD. It was notable that 79% of patients who experienced PR or SD were reported to have tumors with negative or low PD-L1 expression. Enrollment is complete and this interim analysis suggest the combination of pepinemab plus avelumab is well tolerated and shows initial clinical signals of antitumor activity. Updated clinical response data, as well as additional immunophenotyping of both inflammatory and suppressive myeloid cells will be presented. Citation Format: Jonathan W. Goldman, Terrence L. Fisher, Elizabeth Evans, John E. Leonard, Desa Rae Pastore, Crystal Mallow, Ernest Smith, Andreas Schröeder, Kevin Chin, Michael Shafique, Thaddeus Beck, Megan A. Baumgart, Ramaswamy Govindan, Nashat Gabrail, Rachel E. Sanborn, Alexander I. Spira, Nagashree Seetharamu, Yanyan Lou, Aaron S. Mansfield, Maurice Zauderer. Interim results from CLASSICAL-Lung, phase 1b/2 study of pepinemab (VX15/2503) in combination with avelumab in advanced NSCLC [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT191.

Abstract CT142: A phase I trial of surufatinib plus toripalimab in patients with advanced solid tumor

Abstract Background: Surufatinib is a novel small-molecule inhibitor targeting vascular endothelial growth factor receptors 1, 2 and 3, fibroblast growth factor receptor 1 and colony stimulating factor 1 receptor. Toripalimab (JS001) is a monoclonal humanized IgG4 PD-1 antibody. The potential synergistic antitumor activity of surufatinib and anti-PD-L1 combination regimen had been demonstrated in preclinical study (presented at 2017 AACR). Here, we report the safety and preliminary efficacy results from a phase I trial of surufatinib plus toripalimab in patients with advanced solid tumor (NCT03879057). Methods: This study is an open-label, dose escalation and expansion study in solid tumor patients who had failed standard therapies or had no effective treatment. In dose escalation stage, 3 dose levels of surufatinib (200, 300 and 250 mg once daily) were evaluated in combination with a fixed dose of toripalimab 240 mg every 3 weeks until the maximum tolerated dose (MTD) or recommended phase II dose (RP2D) was reached, which ever occurred first. Additional patients were enrolled at dose expansion phase to further assess the efficacy, safety and pharmacokinetic (PK) profile. Results: As of 2020-1-20, a total of 30 patients were enrolled. Tumor types include neuroendocrine tumor (NET) Grade (G) 1/2 (4), NET G3 (4), neuroendocrine carcinoma (NEC) (13), colorectal carcinoma (CRC) (4), gastric adenocarcinoma (GC) (2), esophageal squamous cell carcinoma (ESCC) (2) and metastatic squamous cell carcinoma with unknown primary (1). The RP2D was determined at surufatinib 250 mg daily plus toripalimab. One patient at 300 mg experienced dose-limiting toxicity, grade 3 hyperthyroidism. The most common grade 3/4 treatment emergent adverse events (TEAE, ≥5%) were transaminase elevation, bilirubin elevation, fatigue, hyponatremia, and vomit, with higher frequencies in the 300 mg cohort compared with lower dose cohorts. There was no treatment-related fatal serious adverse event. Preliminary PK analysis showed surufatinib exposure at steady state increased dose-proportionally. Individual PK profiles was comparable to those of surufatinib or toripalimab from previous monotherapy trials. By 2020-1-10, 25/30 patients across 3 cohorts were evaluable for tumor response: 1 complete response, 6 partial response (ORR=28%); in NET G1/2 (3), NEC (2), ESCC (1), and CRC (1). Twelve patients experienced stable disease for at least 6 weeks (DCR=76%). Most patients with negative or low PD-L1 expression achieved PR or CR. Of 21 evaluable neuroendocrine neoplasms (NENs) patients, the ORR and DCR were 23.8% and 81.0%, respectively. Four of 8 evaluable patients at RP2D achieved PR, and the ORR and DCR were 50% and 100%, respectively. Conclusions: Surufatinib plus toripalimab were well tolerated with no unexpected safety signals observed, and showed encouraging antitumor activity in patients with advanced solid tumor, especially in NENs patients. The phase II trial (NCT04169672) has been initiated. Citation Format: Ming Lu, Yanshuo Cao, Jifang Gong, Yu Sun, Jie Li, Lin Shen. A phase I trial of surufatinib plus toripalimab in patients with advanced solid tumor [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr CT142.

947 - A combination of positive tumor HLA-I and negative PD-L1 expression provides an immune rejection mechanism in bladder cancer

947 - A combination of positive tumor HLA-I and negative PD-L1 expression provides an immune rejection mechanism in bladder cancer