Baseline sPD-L1 Research Articles

Plasma sPD-L1 and VEGF levels are associated with the prognosis of NSCLC patients treated with combination immunotherapy.

The clinical significance of plasma soluble programmed cell death ligand 1 (sPD-L1) and vascular endothelial growth factor (VEGF) for non-small cell lung cancer (NSCLC) treated with the combination of anti-angiogenic therapy and anti-PD-L1 antibody (Ab) remain unknown. This study aimed to explore the association between plasma sPD-L1 and VEGF levels and the prognosis of NSCLC patients treated with the combination of Envafolimab and Endostar. Peripheral blood samples were collected from 24 NSCLC patients at baseline and after 6 weeks of treatment and were detected for sPD-L1 and VEGF levels. Both baseline and posttreatment sPD-L1 were significantly higher in progressive disease (PD) group than in controlled disease (CD) group (median: 77.5 pg/ml vs. 64.6 pg/ml, P = 0.036, median: 8451 pg/ml vs. 5563 pg/ml, P = 0.012). In multivariate analysis, lower baseline sPD-L1 levels were significantly associated with longer progression-free survival (PFS) (HR = 6.834, 95% CI: 1.350-34.592, P = 0.020). There were significantly higher posttreatment VEGF levels in PD group compared with CD group (median: 323.7 pg/ml vs. 178.5 pg/ml, P = 0.009). Higher posttreatment VEGF levels were significantly associated with shorter PFS in multivariate analysis (HR = 5.911, 95% CI: 1.391-25.122, P = 0.016). Plasma sPD-L1 and VEGF levels are associated with the clinical response and prognosis of NSCLC patients treated with the combination of PD-L1 inhibitors and anti-angiogenetic therapy.

Prognostic significance of soluble PD-L1 in prostate cancer.

The aim of this study was to assess the role of sPD-L1 and sPD-1 as potential biomarkers in prostate cancer (PCa). The association of the values of these soluble proteins were correlated to the clinical data: stage of disease, Gleason score, biochemical recurrence etc. For a comprehensive study, the relationship between sPD-L1 and sPD-1 and circulating immune cells was further investigated. A total of 88 patients with pT2 and pT3 PCa diagnosis and 41 heathy men were enrolled. Soluble sPD-L1 and sPD-1 levels were measured in plasma by ELISA method. Immunophenotyping was performed by flow cytometry analysis. Our study's findings demonstrate that PCa patients had higher levels of circulating sPD-L1 and sPD-1 comparing to healthy controls (p < 0.001). We found a statistically significant (p < 0.05) relationship between improved progression free survival and lower initial sPD-L1 values. Furthermore, patients with a lower sPD-1/sPD-L1 ratio were associated with a higher probability of disease progression (p < 0.05). Additionally, a significant (p < 0.05) association was discovered between higher Gleason scores and elevated preoperative sPD-L1 levels and between sPD-1 and advanced stage of disease (p < 0.05). A strong correlation (p < 0.05), between immunosuppressive CD4+CD25+FoxP3+ regulatory T cells and baseline sPD-L1 was observed in patients with unfavorable postoperative course of the disease, supporting the idea that these elements influence each other in cancer progression. In addition to the postoperative drop in circulating PD-L1, the inverse relationship (p < 0.05), between the percentage of M-MDSC and sPD-L1 in patients with BCR suggests that M-MDSC is not a source of sPD-L1 in PCa patients. Our findings suggest the potential of sPD-L1 as a promising prognostic marker in prostate cancer.

MP28-07 THE ASSOCIATION OF SOLUBLE PD-L1 AND TREATMENT RESPONSE TO NIVOLUMAB IN PATIENTS WITH METASTATIC RENAL CELL CARCINOMA

You have accessJournal of UrologyCME1 Apr 2023MP28-07 THE ASSOCIATION OF SOLUBLE PD-L1 AND TREATMENT RESPONSE TO NIVOLUMAB IN PATIENTS WITH METASTATIC RENAL CELL CARCINOMA Naoto Wakita, Yukari Bando, Junya Furukawa, Nobuyuki Hinata, Yuzo Nakano, and Masato Fujisawa Naoto WakitaNaoto Wakita More articles by this author , Yukari BandoYukari Bando More articles by this author , Junya FurukawaJunya Furukawa More articles by this author , Nobuyuki HinataNobuyuki Hinata More articles by this author , Yuzo NakanoYuzo Nakano More articles by this author , and Masato FujisawaMasato Fujisawa More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003256.07AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Effective treatment options for metastatic renal cell carcinoma (mRCC) have been increasing. Therefore, predictors of treatment response are important. PD-L1 expression in renal cancer has been reported as a predictor of treatment response and prognosis. However, PD-L1 expression by immunohistochemistry is invasive and difficult to assess repeatedly. Recently, it has been shown that soluble PD-L1 (sPD-L1) is useful as a predictor in several tumors. Therefore, we evaluated sPD-L1 in mRCC patients treated with nivolumab and investigated the association between sPD-L1 and treatment response. METHODS: This study was a prospective single-arm study. Patients with mRCC treated with nivolumab as second line or later were included. We measured serum sPD-L1 in patients before and during treatment. The patients were classified based on baseline sPD-L1 (sPDL1 ≥0.23 ng/ml vs <0.23 ng/ml). We compared outcomes between the two groups. RESULTS: A total of 43 patients with mRCC were included in this study, with 17 (39.5%) low sPD-L1 patients and 26 (60.5%) high sPD-L1 patients. The International Metastatic RCC Database Consortium risk score was significantly poorer in the high sPD-L1 group. The objective response rate was significantly higher (41.2% vs 7.7%) and overall survival significantly longer (p=0.03) in the low group compared with the high group. There were no significant differences in progression-free survival between the two groups. CONCLUSIONS: The present study indicated that sPD-L1 might be a predictor of treatment response to nivolumab for mRCC patients. Source of Funding: This work was supported by Ono Pharmaceutical Co., Ltd. and Bristol-Myers Squibb, Co © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e372 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Naoto Wakita More articles by this author Yukari Bando More articles by this author Junya Furukawa More articles by this author Nobuyuki Hinata More articles by this author Yuzo Nakano More articles by this author Masato Fujisawa More articles by this author Expand All Advertisement PDF downloadLoading ...

Association between response to anti-PD-1 treatment and blood soluble PD-L1 and IL-8 changes in patients with NSCLC

In this study, we explored the dynamic changes in blood sPD-L1 and its clinical value during anti-PD-1 immunotherapy in non-small cell lung cancer (NSCLC) patients. First, we established a sandwich ELISA for functional sPD-L1 that can bind to PD-1 and has biological functions. By monitoring functional sPD-L1 in 39 NSCLC patients treated with anti-PD-1 antibodies, we found a positive correlation between baseline sPD-L1 and tissue PD-L1 (P = 0.0376, r = 0.3581), with patients with lymph node metastasis having higher sPD-L1 levels (P = 0.0037) than those without lymph node metastasis. Although baseline functional sPD-L1 and PFS did not correlate significantly in this study, changes in sPD-L1 in patients with different clinical responses showed different trends. Blood sPD-L1 increased in 93% of patients after two cycles of anti-PD-1 treatment (P = 0.0054); sPD-L1 in nonresponsive patients continued to increase (P = 0.0181), but sPD-L1 started to decline in responsive patients. Blood IL-8 levels were associated with tumor load, and when combined with IL-8, the evaluation accuracy of sPD-L1 improved to 86.4%. This study preliminarily shows that the combination of sPD-L1 and IL-8 is a convenient and effective method for monitoring and evaluating the effectiveness of anti-PD-1 immunotherapy in NSCLC patients.

Rescuing Cancer Immunity by Plasma Exchange in Metastatic Melanoma (ReCIPE-M1): protocol for a single-institution, open-label safety trial of plasma exchange to clear sPD-L1 for immunotherapy

BackgroundPatients with metastatic melanoma rely on PD-(L)1 immunotherapy, but only one-third of patients experience treatment response and all initial responders eventually develop resistance. Tumour-derived extracellular vesicles expressing Programmed death ligand...

Soluble PD-L1 as an early marker of progressive disease on nivolumab

BackgroundSoluble PD-L1 (sPD-L1) has been associated with worse prognosis in numerous solid tumors. We determined sPD-L1 levels before and during nivolumab treatment in two prospective clinical trials of metastatic clear...

Biomarkers for Locally Advanced Hepatocellular Carcinoma Patients Treated with Liver-Directed Combined Radiotherapy

Introduction: In the era of biomarker-driven cancer therapy, robust biomarkers for hepatocellular carcinoma (HCC) have not been well-defined. In this hypothesis-generating study, we investigated biomarkers that can be incorporated to predict treatment outcomes in patients with locally advanced HCC who are administered liver-directed combined radiotherapy (LDCRT). Methods: Ninety-nine patients with HCC who were treated with conventional fractionation LDCRT between July 2016 and October 2018 were enrolled in this prospective single-arm study. Clinical outcomes and possible serum biomarkers, including soluble programmed cell death ligand-1 (sPD-L1), interleukin (IL)-10, IL-6, cell-free DNA (cfDNA), inter-alpha inhibitor H4, and interferon-gamma, were analyzed. The primary endpoint was disease progression, and additional endpoints were local failure-free rate, intrahepatic failure-free rate, and lung metastasis-free rate. Results: The median follow-up period was 18.7 months. The 1-year progression-free rate was 38.2%. Increasing baseline sPD-L1 per pg/mL, previous treatment history, protein induced by vitamin K absence-II >1,629 mAU/mL, and multiple tumors were the adverse factors for progression based on multivariate analysis. Survival tree analysis revealed three prognostic groups for progression, in which patients with multiple lesions and baseline sPD-L1 ≥41.07 pg/mL showed the worst outcomes. For dynamic changes in biomarker levels, sPD-L1 fold change and cfDNA fold-change values were unfavorable factors for progression. Conclusion: Baseline sPD-L1, sPD-L1 fold change, and cfDNA fold-change values showed the highest potential as biomarkers for predicting post-treatment progression after LDCRT in HCC patients. By incorporating clinical factors, these biomarkers may be useful for devising a biomarker-driven treatment paradigm in locally advanced HCC.

The Association Between the Change of Soluble Programmed Cell Death Ligand-1 (sPD-L1) and the Radiosensitivity in Patients With Hypopharyngeal Squamous Cell Carcinoma

The aim of this study was to evaluate the change of sPD-L1 in the plasma of hypopharyngeal squamous cell carcinoma (HSCC) patients before and after radiotherapy (RT) and to explore their relationship with the sensitivity to radiotherapy.A total of 50 patients and 12 healthy individuals were enrolled. All blood samples were collected before RT and 38 blood samples were obtained after RT. Twenty-three matched formalin-fixed, paraffin-embedded (FFPE) specimen from patient tumor biopsies were examined PD-L1 immunohistochemistry, and the sPD-L1 levels were quantified by enzyme-linked immunosorbent assay (ELISA).The level of plasma sPD-L1 in patients were higher than healthy individuals. Plasma sPD-L1 levels at diagnosis correlated positively with T stage, but no association and difference between baseline sPD-L1 levels and other factors, including gender, age, N stage, prognostic stage and blood cell counts. The level of sPD-L1 in plasma had moderate correlations with PD-L1 expression on tumor cells. Notably, it is classified into decreased or increased groups depending on change of the concentration of sPD-L1 after RT, and the study found the sensitivity to radiotherapy of decreased group were higher than increased group.The study reported that sPD-L1 can be detectable in the plasma of HSCC. Besides, the change of plasma sPD-L1 following radiotherapy might be of guided significance for predicting the sensitivity to radiotherapy.

High Serum PD-L1 Levels Are Associated with Poor Survival in Urothelial Cancer Patients Treated with Chemotherapy and Immune Checkpoint Inhibitor Therapy.

Simple SummaryAdvanced urothelial bladder cancer (BC) shows a heterogeneous response to both platinum and immune checkpoint inhibitor (ICI) therapies. The PD-1/PD-L1 signaling pathway represents an immune escape mechanism and tissue PD-L1 expression was shown to be associated with patients’ prognosis and therapy response in various solid tumors. In the present study, we found for the first time that higher pretreatment serum PD-L1 levels are associated with shorter survival in platinum- and ICI-treated BC patients.Serum PD-L1 (sPD-L1) levels are associated with prognosis in various tumors but has not yet been investigated in advanced bladder cancer. We assessed pretreatment serum samples from 83 BC patients who received platinum chemotherapy and from 12 patients who underwent immune checkpoint inhibitor (ICI) therapy. In addition, on-treatment samples from further therapy cycles were collected during chemotherapy (n = 58) and ICI therapy (n = 11). Serum PD-L1 levels were determined using ELISA. High baseline sPD-L1 levels were associated with worse ECOG status (p = 0.007) and shorter overall survival for both chemotherapy- and ICI-treated patients (p = 0.002 and p = 0.040, respectively). Multivariate analysis revealed high baseline sPD-L1 level as an independent predictor of poor survival for platinum-treated patients (p = 0.002). A correlation analysis between serum concentrations of PD-L1 and matrix metalloprotease-7 (MMP-7)—a protease which was recently found to cleave PD-L1—revealed a positive correlation (p = 0.001). No significant sPD-L1 changes were detected during chemotherapy, while in contrast we found a strong, 25-fold increase in sPD-L1 levels during atezolizumab treatment. In conclusion, our work demonstrates that pretreatment sPD-L1 levels are associated with a poor prognosis of BC patients undergoing platinum and ICI therapy. Future research should prospectively address the value of sPD-L1 in predicting treatment response.

The Change of Soluble Programmed Cell Death-Ligand 1 in Glioma Patients Receiving Radiotherapy and Its Impact on Clinical Outcomes.

BackgroundThe programmed cell death ligand 1 (PD-L1) plays a key role in glioma development. However, due to the specificity of glioma’s anatomical position, the role of its expression as a tumor biomarker is limited. It has been proven that the levels of soluble programmed death-ligand 1 (sPD-L1) are associated with prognosis in many malignancies including glioma. However, the expression of sPD-L1 in glioma patients receiving radiotherapy (RT) remains unclear. The purpose of this study was to evaluate the concentration of sPD-L1 in the plasma of glioma patients before and after RT and to explore its relationship with clinical outcomes.MethodsBetween October 2017 and September 2018, glioma patients treated with RT (30 ± 10 Gy, 2 Gy/f) were enrolled, and blood samples were collected before and after RT. We quantified the sPD-L1 levels by enzyme-linked immunosorbent assay (ELISA). The isocitrate dehydrogenase-1 (IDH-1) mutational status and Ki-67 expression of tumors were evaluated by immunohistochemistry. Glioma murine model were used to address whether circulating sPD-L1 molecules are directly targeted by an anti-PD-L1 antibody. The associations between sPD-L1 and clinical features were assessed with Pearson’s or Spearman’s correlation analysis. The progression-free survival (PFS) and overall survival (OS) were determined by the Kaplan-Meier method.ResultsSixty glioma patients were included, with a median age of 52 years. The proportions of grade I, II, III, and IV gliomas were 6.7%, 23.3%, 28.4%, and 41.6%, respectively. The baseline sPD-L1 levels were significantly associated with tumor grade, IDH-1 mutation status and Ki-67 expression. Using 14.35 pg/ml as the cutoff, significantly worse PFS and OS were both observed in patients with higher baseline levels of sPD-L1 (P = 0.027 and 0.008, respectively). RT significantly increased the mean level of sPD-L1 (P < 0.001). Further analysis showed that the level of sPD-L1 in IDH-1 mutation patients was higher than that in wild-type patients. Furthermore, an analysis of glioma murine model indicated that anti-PD-L1 antibody combine with RT can be a potentially powerful cancer therapy.ConclusionThis study reported that sPD-L1 might be a potential biomarker to predict the outcome in glioma patients receiving RT. The elevated level of sPD-L1 after RT suggested that the strategy of a combination of immune checkpoint inhibitors and RT might be promising for glioma patients, especially for those with IDH-1 mutations.

Prognostic Value of Serum Soluble Programmed Death-Ligand 1 and Dynamics During Chemotherapy in Advanced Gastric Cancer Patients.

PurposeThe soluble form programmed death-ligand 1 (sPDL1) has immunosuppressive properties and is being studied as a candidate biomarker for immuno-oncology drug development. We measured the serum sPDL1 at pre-and post-chemotherapy and evaluated its prognostic implication and dynamics during chemotherapy in advanced gastric cancer (GC).Materials and MethodsWe prospectively enrolled 68 GC patients who were candidates for palliative standard first-line chemotherapy, and serially collected blood at baseline and after one cycle of chemotherapy, at the best response and after disease progression. sPDL1 was measured using an enzyme-linked immunosorbent assay. Response to chemotherapy, overall survival (OS), progression-free survival (PFS) and other prognostic factors including neutrophil-lymphocyte ratio (NLR) were obtained. The cut-off value of sPDL1 levels for survival analysis was found using C-statistics.ResultsThe median baseline sPDL1 was 0.8 ng/mL (range, 0.06 to 6.06 ng/mL). The median OS and PFS were 14.9 months and 8.0 months, respectively. sPDL1 and NLR showed a weak positive correlation (Spearman’s rho=0.301, p=0.013). Patients with low levels of sPDL1 at diagnosis (< 1.92 ng/mL) showed a better OS and PFS than patients with a high sPDL1. The baseline sPDL1 before treatment was higher in the progressive disease group than in the stable disease and partial response groups. Patients whose sPDL1 increased after the first cycle of chemotherapy showed worse PFS and OS. Following disease progression, sPDL1 increased compared with the baseline.ConclusionsPDL1 at prechemotherapy confers a prognostic value for PFS and OS in GC patients under palliative first-line chemotherapy. Dynamics of sPDL1 during chemotherapy correlates with disease progression.

Soluble PD-L1 as a Predictor of the Response to EGFR-TKIs in Non-small Cell Lung Cancer Patients With EGFR Mutations.

Programmed cell death ligand 1 (PD-L1) expressed on tumor tissues is a vital molecule for immune suppression and its impact on the response to epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) has been reported. The significance of soluble PD-L1 (sPD-L1) for lung cancer patients remains unknown. This study investigated whether sPD-L1 could predict the response of EGFR-mutated non-small cell lung cancer (NSCLC) to EGFR-targeted therapy. We retrospectively evaluated patients who received first-line treatment with EGFR-TKIs for advanced NSCLC with EGFR mutations. Pre-treatment plasma concentrations of PD-L1 and on-treatment (1 month after treatment initiation) plasma concentrations of PD-L1 were measured using the R-plex Human PD-L1 assay. The association between the sPD-L1 level and the clinical outcome was analyzed. Among 66 patients who were eligible for the study, patients with high pre-treatment or on-treatment sPD-L1 levels had decreased objective response rate (ORR) compared with that of patients with low sPD-L1 levels (39.4 vs. 66.7%, p = 0.026 for pre-treatment sPD-L1 level, and 43.5 vs. 73.9%, p = 0.025 for on-treatment sPD-L1 level). A high baseline sPD-L1 level was associated with a shortened progression-free survival (PFS) rate (9.9 vs. 16.1 months, p = 0.005). Both univariate and multivariate analyses showed that a high baseline sPD-L1 level was an independent factor associated with the PFS (hazard ratio [HR] 2.56, p = 0.011). Our study revealed that the sPD-L1 level was strongly related to the outcome of EGFR-TKIs in NSCLC patients harboring EGFR mutations.

Soluble PD-L1 as a marker of progressive disease on nivolumab in kidney cancer.

746 Background: Higher levels of soluble PD-L1 (sPD-L1) are associated with poor prognosis in patients with solid tumors including in renal cell carcinoma (RCC). Here we have tested whether in patients with advanced RCC, sPD-L1 levels are associated with PD-L1 expression on tumor tissue or with clinical outcomes on PD-1 blockade. Methods: Serum from 91 patients with advanced clear-cell RCC on a biomarker study of nivolumab (NCT01358721) obtained at baseline (Day 1), Day 29 and Day 63, was tested by SiMoa™ for sPD-L1 (capture mAb 298.12B1, detection mAb 339.4C10; Freeman laboratory and Quanterix). Tumor PD-L1 (tPD-L1) was assessed on pretreatment biopsies (Dako). Association of sPDL1 and tPD-L1 with clinical outcomes was analyzed, including best overall response by RECIST (BOR), objective response of &gt;20% (OR), progression free survival (PFS), and overall survival (OS). Results quote Wilcoxon Rank Sum test or paired t-test with significance at P &lt; 0.05. Results: Median sPD-L1 was highest in patients with progressive disease (PD) at all timepoints (Table). Compared to baseline, sPD-L1 levels significantly increased in patients with PD on Day 29 and Day 63, while sPD-L1 levels significantly decreased in patients with CR/PR on Day 63. In addition, we found significantly higher baseline sPD-L1 in patients with prior therapy compared to those who were treatment-naïve. High tPD-L1 was weakly associated with favorable OR, but also weakly associated with high baseline sPD-L1. Conclusions: Unlike tPD-L1, sPD-L1 levels may show promise for association with clinical response to nivolumab in RCC. In this exploratory study, sPD-L1 increase on-treatment was significantly associated with lack of OR, and may be of utility as an early marker for PD worthy of future validation. Analysis of RNASeq from patients’ tumor specimen is underway to assess whether high sPD-L1 with PD is associated with immune suppressive signatures.[Table: see text]

Determining and Incorporating the Optimal Predictive Biomarkers in Hepatocellular Carcinoma Patients Treated with Radiotherapy

Radiotherapy (RT) is one of the treatment options for treating hepatocellular carcinoma (HCC) patients. However, treatment responses to RT are heterogeneous and no robust predictive biomarker has been found. Previously, our institution reported the possibility of soluble programmed cell death ligand-1 (sPD-L1), plasma cell-free DNA (cfDNA), inter-alpha inhibitor H4 (ITIH4), interleukin (IL)-6, and IL-10 as predictive biomarkers after RT. However, using a single biomarker to predict treatment outcomes has limitations since the heterogeneity of the tumor and the host-immune system both affect tumor response and oncologic outcomes. Thus, we investigated the optimal biomarkers and incorporated them to predict treatment outcomes in HCC patients treated with RT. Hundred-four HCC patients treated with RT between July 2016 and October 2018 were prospectively enrolled. Conventional RT was performed in all patients, with a median RT dose of 100 Gy (range, 60–100 Gy) for GTV and a median RT dose of 60 Gy (range, 45–60 Gy) for PTV. Peripheral blood was collected at baseline and after RT. A total of six biomarkers, sPD-L1, IL-10, IL-6, cfDNA, ITIH4 and IFN-γ, were analyzed. Median follow up period was 14.7 months (range, 2.3–28.9 months). Median age was 61 (range, 33–80), 44 patients (44.4%) had single tumor and the median tumor size was 6.5 cm (range, 1.3–21.0 cm). Nine patients had node-positive disease and 52 patients had portal vein tumor thrombosis or invasion. One-year overall survival rates and progression-free rates were 85.1% and 38.6%, respectively. The most common first pattern of failure was regional only failure, followed by distant only failure. Recursive partitioning analysis revealed four prognostic groups for regional failure based on sPD-L1, IL-10, and number of hepatic lesions: group 1, sPD-L1 < 8.17 pg/mL; group 2, sPD-L1 ≥ 8.17 pg/mL, single tumor; group 3, sPD-L1 ≥ 8.17 pg/mL, multiple tumors, IL-10 < 3.64 pg/mL; group 4, sPD-L1 ≥ 8.17 pg/mL, multiple tumors, IL-10 ≥ 3.64 pg/mL. Regional failure rate was highest in group 4 and lowest in group 1 (p < 0.001). Also, three prognostic groups for progression using post-RT biomarker values were defined based on cfDNA and sPD-L1: group 1, cfDNA < 4.47 μg/mL, sPD-L1 < 19.38 pg/mL; group 2, cfDNA < 4.47 μg/mL, sPD-L1 ≥ 19.38 pg/mL; group 3, cfDNA ≥ 4.47 μg/mL. Progression rate was highest in group 3 and lowest in group 1 (p < 0.001). This is the first study to incorporate multiple blood-based biomarkers to predict treatment outcomes in HCC patients who received RT. Baseline sPD-L1 and IL-10 level for regional recurrence and post-RT cfDNA and sPD-L1 level for progression showed potential as predictive biomarkers. However, the potential to predict survival or overall progression remains limited and further validation in a larger cohort is needed.

Prognostic value of serum soluble programmed death-ligand 1 (sPDL1) and dynamics during chemotherapy in advanced gastric cancer patients.

4034 Background: The soluble form Programmed Death-Ligand 1(sPDL1) is suggested to have immunosuppressive activity and under investigation as candidate biomarker for immuno-oncology drug development. In this study, we measured the serum sPDL1 at pre-and post-chemotherapy and evaluated its prognostic implication and dynamics during chemotherapy in advanced gastric cancer (GC). Methods: We prospectively enrolled 68 GC patients who were candidates for palliative standard 1st-line chemotherapy, and blood was serially collected at pre-and post-one cycle of chemotherapy, at best response and disease progression. sPDL1 was measured using an enzyme-linked immunosorbent assay. Response to chemotherapy, overall survival (OS), progression-free survival (PFS) and other prognostic factors including neutrophil-lymphocyte ratio (NLR) were obtained. The cut-off values of sPDL1 levels and changes for survivals were found using C-statistics. Results: The median baseline sPDL1 was 0.8ng/mL(range, 0.06 - 6.06ng/mL). The median OS and PFS were 14.9 months (95% CI: 7.33-22.47) and 8.0 months (95% CI: 5.96-10.0), respectively. sPDL1 and NLR showed a positive correlation. Patients with low levels of sPD-L1 at diagnosis ( &lt; 1.92 ng/mL) showed a better OS and PFS than the patients with a high sPDL1 (OS: 18.3 vs. 95 months, P = 0.057, PFS: 8.9 vs. 6.0 months, P = 0.04). The baseline sPDL1 before treatment were higher in the PD group than in the SD and PR groups (mean:2.91, 1.17, 1.19, P = 0.019). Patients whose sPDL1 increased after 1st cycle of chemotherapy showed the tendency of worse PFS and OS. When disease progressed, sPDL1 increased compared with baseline (mean:1.31, 1.45, P = 0.029). Conclusions: sPDL1 at pre-chemotherapy confers the prognostic value for PFS and OS in GC patients under palliative 1st-line chemotherapy. The dynamics of sPDL1 during chemotherapy correlates with disease courses.

The prognostic role of soluble transforming growth factor-β (sTGFb) and soluble programmed death-ligand 1 (sPDL1) in biliary tract cancer patients treated with binimetinib and capecitabine.

257 Background: Transforming growth factor (TGF) -β signaling is important for tumor growth and metastasis in biliary tract cancer (BTC). TGF-β attenuates tumor response to programmed death-ligand 1 (PD-L1) blockade. This study aimed to evaluate a correlation between soluble TGF-β (s TGF-β) and soluble PD-L1 (sPD-L1) and its prognostic role in BTC. Methods: Study population consisted of 34 patients enrolled in phase Ib clinical trial of binimetinib (MEK inhibitor) with capecitabine in gemcitabine-pretreated BTC (ClinicalTrials.gov: NCT02773459). Blood samples at screening, after first cycle, after second cycle, and at disease progression were prospectively collected. Plasma sTGF-β and sPD-L1 values were measured by using an enzyme-linked immunosorbent assay. Results: In total 34 patients, 25 (73.5%) and 9 patients (26.5%) were second-line and third-line setting, respectively. Median progression-free survival (PFS) and overall survival (OS) were 4.1 and 7.8 months. The mean baseline sTGF-β and sPD-L1 were 18.7 ng/ml and 3.1 ng/ml. There was a positive correlation between sTGF-β and sPD-L1 value (pearson correlation = 0.596, p &lt; 0.001). Mean baseline value was likely to be higher in best response of progressive disease, followed by stable disease and partial response. Similarly, higher baseline sTGF-β showed significantly shorter PFS (3.4 vs 5.1 months (m), p = 0.047) and OS (5.4 vs 9.7 m, p = 0.042). Higher baseline sPD-L1 also had a trend for poor PFS and OS (PFS: 3.0 vs 4.3 m, p = 0.220; OS: 6.4 vs 9.7 m, p = 0.140). Regarding changes from baseline to after first cycle, sTGF-β change of &gt; 3.6 ng/ml demonstrated significantly shorter OS (5.9 vs 10.8 m, p = 0.020), although PFS did not differ according to sTGF-β change (p = 0.210). In contrast, OS did not differ according to sPD-L1 change (p = 0.190). sPD-L1 change &gt; -1.7 ng/ml even had longer PFS (5.1 vs 2.2 m, p = 0.005). Conclusions: In BTC patients with binimetinib and capecitabine, there is a positive correlation between sTGF-β and sPD-L1 value and higher baseline sTGF-β and sPD-L1 indicate a worse prognosis. The early change of sTGF-β and sPD-L1 during treatment could predict the survival.

Abstract A38: Blood-based T cell biomarkers and soluble PD-L1 predict responses and immune-related toxicity to PD-1 blockade in melanoma and lung cancer

Abstract Despite unprecedented successes with immune checkpoint blockade in advanced cancers, these agents provide durable clinical benefit in only a subset of patients. In addition, the clinical management of patients receiving immune checkpoint blockade remains quite challenging due to the unpredictable and kinetically heterogeneous responses which can manifest as late responses, pseudoprogression, or hyperprogression in subsets of patients. The dynamics and heterogeneity of programmed cell death protein ligand 1 (PD-L1, aka B7-H1) expression confound its use as a predictive biomarker in cancer immunotherapy, but blood-based biomarkers have the potential to predict responders and detect mechanisms of resistance to immunotherapy. We previously reported that Bim (BH3-only protein) is a downstream signaling molecule of the PD-1 pathway, and that Bim levels in circulating tumor-reactive T-cells reflected patient responses to anti-PD-1 therapy in melanoma. We also discovered the existence of soluble PD-L1 (sPD-L1) in the plasma of cancer patients and showed a correlation of sPD-L1 with cancer stages in renal cell carcinoma and with prognosis in metastatic melanoma. Here we evaluated the frequency of tumor-reactive T cells with Bim expression along with effector memory profile and sPD-L1 as biomarkers of response in a new cohort of patients with metastatic melanoma and lung cancer undergoing anti-PD-1 therapy. We recruited 100 cancer patients treated with anti-PD-1 therapy who had peripheral blood collected at baseline and at each subsequent radiographic tumor evaluation. Frequencies of Bim+ and effector memory CD8+ T cells were measured by flow cytometry in gated tumor-reactive CD11a high PD1+ CD8+ T cells. We also measured levels of sPD-L1 in plasma at baseline and serially during treatment with ELISA. Baseline T cell markers and sPD-L1 levels and their percent changes in patients who had a radiographic response were compared to those who had progressive disease (PD). We found that patients with objective response after 4 cycles of anti-PD-1 therapy had higher frequency of Bim+ CD8+ T cells at baseline compared to patients with PD (mean 43% vs. 30%, P=0.0484). The frequencies of Bim+ T cells decreased significantly after the first 3 months of treatment in responders compared with progressors (mean -16% vs. + 40% P=0.0111). The frequency of effector memory CD8+ T cells also dramatically increased in responders in 3-6 months after anti-PD-1 therapy (mean 89% vs. 9.56%, p=0.002). High baseline sPD-L1 was associated with progression on anti-PD-1 therapy (mean 2.8 ng/mL vs. 0.7 ng/mL, p=0.07) or development of immune-related toxicities and the levels increased by 12 weeks in patients progressing on therapy. Conclusion: Measurements of T cell biomarkers (Bim and effector memory) and sPD-L1 levels provide a new noninvasive way to predict and monitor patient responses to anti-PD-1 monotherapy in melanoma and lung cancers. Note: This abstract was not presented at the conference. Citation Format: Roxana S. Dronca, Aaron Mansfield, Xin Liu, Susan Harrington, Elizabeth Enninga, Svetomir Markovic, Lisa Kottschade, Rob Mcwilliams, Matthew Block, Wendy Nevala, Michael Thompson, Haidong Dong. Blood-based T cell biomarkers and soluble PD-L1 predict responses and immune-related toxicity to PD-1 blockade in melanoma and lung cancer [abstract]. In: Proceedings of the AACR Special Conference on Tumor Immunology and Immunotherapy; 2017 Oct 1-4; Boston, MA. Philadelphia (PA): AACR; Cancer Immunol Res 2018;6(9 Suppl):Abstract nr A38.

Bim and soluble PD-L1 (sPD-L1) as predictive biomarkers of response to anti-PD-1 therapy in patients with melanoma and lung carcinoma.

11534 Background: To date, there are no validated blood-based biomarkers of predicting response to PD-1 blockade. We previously reported that Bim is a downstream signaling molecule of the PD-1 pathway, and that measurement of Bim levels in circulating T-cells may predict and monitor responses to anti–PD-1 therapy in melanoma. We have identified the existence of sPD-L1 in cancer patients and showed that the sPD-L1 is biologically active and capable of triggering apoptosis in activated T-cells. Here we evaluated T cell Bim and sPD-L1 in the peripheral blood (PB) as biomarkers of response in a cohort of patients with metastatic melanoma and lung cancer undergoing anti-PD1 therapy. Methods: 60 pts treated with anti-PD-1 had PB collected at baseline and at radiographic tumor evaluation. Frequencies of Bim+ T cells and Bim median fluorescence intensity (MFI) were measured by flow cytometry in gated tumor-reactive CD11ahighPD1+ CD8+ T cells. We also measured levels of sPD-L1 at baseline and serially during treatment with sPD-L1 ELISA. Baseline Bim and sPD-L1 levels and percent change in Bim levels in patients (pts) who had a radiographic response (CR/PR) were compared to those who had progressive disease (PD) at 12 wks. Results: Similarly to previously reported preliminary data, pts with objective response (CR/PR, 15/60) after 4 cycles of anti-PD1 therapy had higher frequency of Bim T cells at baseline compared to pts with PD (16/60) (mean 43% vs. 30%, P = 0.0484). The frequencies of Bim+ T cells decreased significantly after the first 3 months of treatment in responders compared with progressors (mean -16% vs. + 40% P = 0.0111). High baseline sPD-L1 were associated with progression on anti-PD1 therapy (mean 2.8 ng/mL vs. 0.7 ng/mL, p = 0.07, n = 13) and the levels increased by the first tumor assessment in patients resistant to anti-PD-1. Conclusions: Measurements of Bim and sPD-L1 levels may help to select patients who are likely to benefit from anti-PD1 monotherapy versus combinatorial strategies, and provide a new non-invasive way to monitor response to anti-PD-1 blockade. A larger validation study is underway.

Plasma levels of soluble programmed death ligand-1 may be associated with overall survival in nonsmall cell lung cancer patients receiving thoracic radiotherapy.

Immune-checkpoint signaling plays an important role in immunosuppression of tumors. We aimed to investigate the association of soluble programmed death-ligand 1 (sPD-L1) level in plasma with overall survival (OS) in locally advanced or inoperable nonsmall-cell lung cancer (NSCLC) patients treated with thoracic radiotherapy (TRT). We used ELISA to evaluate the sPD-L1 levels at diagnosis and during TRT in 126 clinically inoperable NSCLC patients. OS rates were followed up and recorded. SPSS software and GraphPad Prism 5 were used for statistics. In this study, the average sPD-L1 levels at baseline, week 2, and week 4 during TRT and post-TRT were 107.2, 51.3, 65.4, and 111.1 pg/mL, respectively. Levels of sPD-L1 at week 2 and week 4 were significantly less than at baseline, with both P values < 0.001. Using 96.5 pg/mL as the cutoff, patients with lower baseline sPD-L1 level had longer OS than those with higher sPD-L1 level (27.8 months vs 15.5 months, P = 0.005). Using multivariate analysis, the following factors were significantly associated with longer OS: female, adenocarcinoma, higher TRT dose, and lower baseline sPD-L1 level. Patients with both characteristics of lower baseline sPD-L1 level and higher TRT dose (BED10 ≥84 Gy) had the longest OS. To conclude, the lower baseline sPD-L1 level was significantly associated with longer OS in NSCLC patients treated with TRT, which may serve as an independent biomarker and needs further clinical study.