Association between serum level soluble programmed cell death ligand 1 and prognosis in patients with non-small cell lung cancer treated with anti-PD-1 antibody

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.

Prospective Observational Study of Ramucirumab Plus Docetaxel After Combined Chemoimmunotherapy in Patients With Non-Small-Cell Lung Cancer

BACKGROUND

A history of pre-administration of immune checkpoint inhibitors has been reported to be associated with good outcomes of ramucirumab (RAM) plus docetaxel (DOC) combination therapy for advanced non-small-cell lung cancer (NSCLC). However, existing knowledge on the clinical significance of RAM and DOC following combined chemoimmunotherapy is limited. Therefore, we evaluated the efficacy and safety of RAM plus DOC therapy after combined chemoimmunotherapy and attempted to identify the predictors of its outcomes.

PATIENTS AND METHODS

This multicenter, prospective study investigated the efficacy and safety of RAM plus DOC after combined chemoimmunotherapy. The primary endpoint was progression-free survival (PFS). Secondary endpoints were the objective response rate (ORR), disease control rate (DCR), overall survival (OS), and incidence of adverse events. An exploratory analysis measured serum cytokine levels at the start of treatment.

RESULTS

Overall, 44 patients were enrolled from 10 Japanese institutions between April 2020 and June 2022. The median PFS and OS were 6.3 and 22.6 months, respectively. Furthermore, the ORR and DCR were 36.4% and 72.7%, respectively. The high vascular endothelial growth factor D (VEGF-D) group had a significantly shorter PFS and OS. A combination of high VEGF-A and low VEGF-D levels was associated with a longer PFS.

CONCLUSION

Our results showed that RAM plus DOC after combined chemoimmunotherapy might be an effective and relatively feasible second-line treatment for patients with advanced NSCLC in a real-world setting.

Soluble programmed death ligand 1 as prognostic biomarker in non-small cell lung cancer patients receiving nivolumab, pembrolizumab or atezolizumab therapy

Many studies have focused on the prognostic role of soluble programmed death ligand 1 (sPD-L1) in non-small cell lung cancer (NSCLC), but outcomes are ambiguous and further investigations are needed. We addressed the matter by studying sPD-L1 in baseline samples and in longitudinal samples taken prior to three subsequent cycles of anti-PD-1/anti-PD-L1 treatments. Eighty patients with NSCLC were enrolled. Median sPD-L1 level at baseline was 52 pg/mL [95% confidence interval (CI) 49-57]. In patients treated with pembrolizumab and nivolumab, the concentration of sPD-L1 remained rather stable throughout treatment. In contrast, sPD-L1 rose by 50-fold following the first cycle of atezolizumab therapy. We found the baseline level of sPD-L1 to be related to overall survival (OS) after two years of follow-up in simple Cox analysis (p = 0.006) and multiple Cox Regression, hazard ratio 1.02 (95% CI 1.00-1.03) (p = 0.033). There was no association between sPD-L1 and tissue PD-L1 expression, overall response rate, or progression free survival. In conclusion, sPD-L1 measured in baseline serum samples may be associated with OS in NSCLC patients receiving anti-PD1/anti-PD-L1 treatment. Importantly, the results signify that further research is warranted to explore the clinical utility of sPD-L1 in patients treated with anti-PD-L1.

[The circulating PD-L1: An emerging predictive biomarker for immune checkpoint inhibitors response]

Immune checkpoint inhibitors (ICI) have recently become the standard of care for many metastatic solid tumors, with considerable improvements in patient prognosis. However, a non-negligible proportion of patients does not respond to this type of treatment, making it essential to identify predictive factors of this response in order to better adapt the therapy. Among the biomarkers that have been most extensively studied in recent years, tumor PD-L1 levels come out on top, with controversial results for predicting response to ICI. The determination of circulating PD-L1 (or soluble PD-L1) in peripheral blood seems to be an interesting emerging biomarker. Indeed, several studies have investigated its prognostic value, and/or its potential predictive value of response to immunotherapy, and it would appear that there is a correlation between the level of soluble PD-L1 and the level of tumor aggressiveness and therefore prognosis. Furthermore, the results suggest that higher PD-L1 levels are associated with a poorer response to immunotherapy, although this remains to be confirmed in large-scale studies.

Missing prognostic value of soluble PD-1, PD-L1 and PD-L2 in lung cancer patients undergoing chemotherapy - A CEPAC-TDM biomarker substudy

BACKGROUND

Programmed cell death receptors and ligands in cancer tissue samples are established companion diagnostics for immune checkpoint inhibitor (ICI) therapies.

OBJECTIVE

To investigate the relevance of soluble PD-1, PD-L1 and PD-L2 for estimating therapy response and prognosis in non-small cell lung cancer patients (NSCLC) undergoing platin-based combination chemotherapies.

METHODS

In a biomarker substudy of a prospective, multicentric clinical trial (CEPAC-TDM) on advanced NSCLC patients, soluble PD-1, PD-L1 and PD-L2 were assessed in serial serum samples by highly sensitive enzyme-linked immunosorbent assays and correlated with radiological response after two cycles of chemotherapy and with overall survival (OS).

RESULTS

Among 243 NSCLC patients, 185 achieved response (partial remission and stable disease) and 58 non-response (progression). The distribution of PD-1, PD-L1 and PD-L2 at baseline (C1), prior to staging (C3) and the relative changes (C3/C1) greatly overlapped between the patient groups with response and non-response, thus hindering the discrimination between the two groups. None of the PD markers had prognostic value regarding OS.

CONCLUSIONS

Neither soluble PD-1, PD-L1 nor PD-L2 did provide clinical utility for predicting response to chemotherapy and prognosis. Studies on the relevance of PD markers in ICI therapies are warranted.

The combination of soluble forms of PD-1 and PD-L1 as a predictive marker of PD-1 blockade in patients with advanced cancers: a multicenter retrospective study

Introduction

The clinical relevance of soluble forms of programmed cell death-1 (sPD-1) and programmed cell death-ligand 1 (sPD-L1) remains unclear. We here investigated the relation between the efficacy of PD-1 blockade and pretreatment plasma levels of sPD-1 and sPD-L1 across a broad range of cancer types.

Methods

We retrospectively analyzed clinical data from 171 patients with advanced solid tumors who received nivolumab or pembrolizumab monotherapy regardless of treatment line. The concentrations of sPD-1 and sPD-L1 were measured with a fully automated immunoassay (HISCL system).

Results

The study subjects comprised patients with head and neck cancer (n = 50), urothelial cancer (n = 42), renal cell cancer (n = 37), gastric cancer (n = 20), esophageal cancer (n = 10), malignant pleural mesothelioma (n = 6), or microsatellite instability-high tumors (n = 6). High or low levels of sPD-1 or sPD-L1 were not significantly associated with progression-free survival (PFS) or overall survival (OS) for PD-1 blockade in the entire study population. Comparison of treatment outcomes according to combinations of high or low sPD-1 and sPD-L1 levels, however, revealed that patients with low sPD-1 and high sPD-L1 concentrations had a significantly poorer PFS (HR of 1.79 [95% CI, 1.13-2.83], p = 0.01) and a tendency toward poorer OS (HR of 1.70 [95% CI, 0.99-2.91], p = 0.05) compared with all other patients.

Conclusion

Our findings suggest that the combination of low sPD-1 and high sPD-L1 levels is a potential negative biomarker for PD-1 blockade therapy.

The influence of plasma sPD-L1 concentration on the effectiveness of immunotherapy in advanced NSCLC patients

INTRODUCTION

PD-L1 (Programmed Cell Death Ligand 1) is currently the only recognised marker of response to immunotherapy with anti-PD-1 or anti-PD-L1 antibodies in patients with advanced non-small cell lung cancer (NSCLC). However, this marker is not perfect. Soluble PD-L1 (sPD-L1) may be a novel predictor of immunotherapy efficacy in NSCLC patients.

MATERIAL AND METHODS

We enrolled 120 patients (median age 68 ± 6.81 years, 70 males and 50 females) with locally advanced (stage IIIB; 10 patients) or advanced (stage IV; 110 patients) NSCLC. PD-L1 expression in tumour cells was assessed by immunohistochemistry (IHC) in 117 (97.5%) patients. The soluble PD-L1 concentration in plasma samples was measured using enzyme-linked immunosorbent assay (ELISA). The response to immunotherapy, progression-free survival (PFS), and overall survival (OS), calculated from the start of immunotherapy, were assessed in 119 patients.

RESULTS

Patients with disease control had significantly lower (p = 0.0006) concentrations of sPD-L1 in blood plasma than patients with progression during the first months of immunotherapy or chemoimmunotherapy Patients with ≥ 6 month progression-free survival had a significantly higher (p = 0.013) percentage of tumor cells with PD-L1 expression than patients with shorter PFS. Patients with ≥ 6 months OS had significantly lower (p = 0.0142) plasma sPD-L1 concentrations than those with shorter overall survival. The median PFS was significantly higher in patients with low sPD-L1 concentrations than in those with high concentrations of this protein (5.8 vs. 2.5 months, HR = 0.6021, p = 0.0156). Similarly, patients with low sPD-L1 levels had a significantly higher median overall survival than those with sPD-L1 levels above the median (16.5 vs. 7 months, HR = 0.5354, p = 0.0071). There was no significant correlation between the percentage of tumour cells expressing PD-L1 and the concentration of sPD-L1 in the blood plasma.

CONCLUSION

High sPD-L1 concentration is a negative predictor of immunotherapy efficacy in patients with NSCLC. It is worthwhile to determine sPD-L1 concentration to predict the risk of resistance to anti-PD-1 or anti-PD-L1 antibodies with greater certainty.

Machine learning algorithm predicts fibrosis-related blood diagnosis markers of intervertebral disc degeneration

BACKGROUND

Intervertebral disc cell fibrosis has been established as a contributing factor to intervertebral disc degeneration (IDD). This study aimed to identify fibrosis-related diagnostic genes for patients with IDD.

METHODS

RNA-sequencing data was downloaded from Gene Expression Omnibus (GEO) database. The diagnostic genes was identified using Random forest based on the differentially expressed fibrosis-related genes (DE-FIGs) between IDD and control samples. The immune infiltration states in IDD and the regulatory network as well as potential drugs targeted diagnostic genes were investigated. Quantitative Real-Time PCR was conducted for gene expression valifation.

RESULTS

CEP120 and SPDL1 merged as diagnostic genes. Substantial variations were observed in the proportions of natural killer cells, neutrophils, and myeloid-derived suppressor cells between IDD and control samples. Further experiments indicated that AC144548.1 could regulate the expressions of SPDL1 and CEP120 by combininghsa-miR-5195-3p and hsa-miR-455-3p, respectively. Additionally, transcription factors FOXM1, PPARG, and ATF3 were identified as regulators of SPDL1 and CEP120 transcription. Notably, 56 drugs were predicted to target these genes. The down-regulation of SPDL1 and CEP120 was also validated.

CONCLUSION

This study identified two diagnostic genes associated with fibrosis in patients with IDD. Additionally, we elucidated their potential regulatory networks and identified target drugs, which offer a theoretical basis and reference for further study into fibrosis-related genes involved in IDD.

Prognostic impact of soluble PD-L1 derived from tumor-associated macrophages in non-small-cell lung cancer

Programmed cell death-ligand 1 (PD-L1) on tumor cells can be degraded to soluble form (sPD-L1) and enter circulation, however, the clinical significances of sPD-L1 in peripheral blood remains to be elucidated in non-small-cell lung cancer (NSCLC). We monitored plasma sPD-L1 levels during perioperative periods and evaluated PD-L1-positive cells in tumor tissues in patients with operable NSCLC. Then the correlation between preoperative plasma sPD-L1 levels and relapse-free survival (RFS) was analyzed retrospectively. In patients who underwent radical surgery (n = 61), plasma sPD-L1 levels (median; 63.5 pg/mL) significantly increased 1 month after surgery (72.2 pg/mL, P < 0.001). The combined score of PD-L1-positive cells including tumor cells and tumor-associated macrophages (TAMs) was significantly associated with preoperative plasma sPD-L1 levels. In patients with high levels of preoperative plasma sPD-L1, the probability of 5-year RFS was significantly poor for patients with low PD-L1 expression intensity of tumor cells (tcPD-L1) compared with those with high tcPD-L1 (33.3% vs. 87.5%, respectively, P = 0.016; 95% CI, 0.013-0.964). In former group, PD-L1-positive TAMs were markedly infiltrating compared with those from latter group (246.4 vs. 76.6 counts/mm2, respectively, P = 0.003). In NSCLC, plasma sPD-L1 can reflect the accumulation of PD-L1-posotive TAMs, not just PD-L1-positive tumor cells. In patients with high levels of preoperative plasma sPD-L1, the prognoses after surgery depends on which PD-L1-positive cells, tumor cells or TAMs, are the primary source of the sPD-L1. Thus, measuring both plasma sPD-L1 levels and PD-L1 expression status of tumor cells and TAMs is of benefit for assessment of postoperative prognosis in operable NSCLC.

Prognostic significance of blood-based PD-L1 analysis in patients with non-small cell lung cancer undergoing immune checkpoint inhibitor therapy: a systematic review and meta-analysis

BACKGROUND

The main types of PD-L1 in the blood include soluble PD-L1 (sPD-L1), exosomal PD-L1 (exoPD-L1), and PD-L1 in circulating tumor cells (CTCs). However, the predictive and prognostic values of these three indicators in patients with non-small cell lung cancer (NSCLC) undergoing immune checkpoint inhibitor (ICI) therapy are unclear, warranting a systematic meta-analysis.

METHODS

A systematic literature search was performed in the PubMed, Cochrane Library, and Embase databases. The pooled hazard ratio (HR) and 95% confidence interval (CI) values were extracted from the included studies to investigate the correlation between the three PD-L1 indicators and overall survival (OS) or progression-free survival (PFS). The Newcastle-Ottawa Scale (NOS) was used to examine the quality of the included studies. Subgroup analyses were employed to investigate the heterogeneity. The publication bias of the included studies was assessed using Begg's and Egger's tests. P < 0.05 was regarded as significantly different.

RESULTS

The pooled results revealed that high pre-treatment sPD-L1 levels were significantly associated with inferior OS (HR = 2.32, 95% CI = 1.68-3.18, P < 0.001) and PFS (HR = 2.52, 95% CI = 1.72-3.68, P < 0.001). However, dynamic changes in sPD-L1 after immunotherapy were not statistically significant for OS (HR = 1.46, 95% CI = 0.65-3.26, P > 0.05) or PFS (HR = 1.62, 95% CI = 0.92-2.86, P > 0.05). Meanwhile, the upregulated pre-treatment exoPD-L1 levels were significantly associated with poor PFS (HR = 4.44, 95% CI = 2.87-6.89, P < 0.001), whereas the post-treatment dynamic upregulation of exoPD-L1 was significantly correlated with superior PFS (HR = 0.36, 95% CI = 0.24-0.54, P < 0.001) and OS (HR = 0.20, 95% CI = 0.07-0.53, P < 0.001). For PD-L1 in CTCs, the pooled results indicated that PD-L1 expression in CTCs was not significantly correlated with OS (HR = 0.75, 95% CI = 0.49-1.13, P = 0.170) and PFS (HR = 0.79, 95% CI = 0.59-1.06, P = 0.12).

CONCLUSIONS

Blood-based PD-L1 analysis is a potential strategy for predicting treatment efficacy and prognosis in patients with cancer.

Meta-analysis of the prognostic value of soluble programmed death ligand-1 (sPD-L1) in cancers

BACKGROUND

The soluble programmed death ligand-1 (sPD-L1) and its prognostic role in cancers have been investigated in numerous studies. However, due to the inconsistency on some findings, this meta-analysis was performed to assess the prognostic value of sPD-L1 in patients with cancer.

METHODS

We searched the PubMed, Web of Science, MEDLINE, Wiley Online Library and ScienceDirect, and screened the studies for eligibility. Recurrence-free survival (RFS), progression-free survival (PFS) and disease-free survival (DFS) were for short term survival. The overall survival (OS) was for long term survival.

RESULTS

Forty studies with 4441 patients were included in this meta-analysis. Elevated sPD-L1 was associated with short OS [HR = 2.44 (2.03-2.94), p = 0.000]. Moreover, a high sPD-L1 was predictive of worse DFS/RFS/PFS [HR = 2.52 (1.83-3.44), p = 0.000]. In addition, high sPD-L1 was consistently correlated with poor OS in irrespective of study type, univariate and multivariate analysis, ethnicity, cut-off value of sPD-L1, sample and treatment. In the subgroup analysis, high sPD-L1 was correlated with poor OS in gastrointestinal cancer, lung cancer, hepatic cancer, oesophageal cancer and clear cell renal cell carcinoma.

CONCLUSIONS

The present meta-analysis showed that a high level of sPD-L1 was associated with worse prognosis in some types of cancer.

The predictive role of soluble programmed death ligand 1 in digestive system cancers

Introduction

The prognostic role of soluble programmed death ligand 1 (sPD-L1) in digestive system cancers (DSCs) remains inconclusive. This study aimed to explore the predictive value of sPD-L1 expression in DSCs.

Methods

Comprehensive searches were run on the electronic databases (PubMed, Web of Science, EMBASE, and the Cochrane Library) to identify studies that assessed the prognostic role of sPD-L1 in DSCs. Review Manager software (version 5.3) was used for all analyses. Pooled data for survival outcomes were measured as hazard ratios (HRs), 95% confidence intervals (CIs), and odds ratios and their 95% CIs.

Results

The search identified 18 studies involving 2,070 patients with DSCs. The meta-outcome revealed that a high level of sPD-L1 was related to poorer overall survival (HR, 3.06; 95% CI: 2.22-4.22, p<0.001) and disease-free survival (HR, 2.53; 95% CI: 1.67-3.83, p<0.001) in DSCs. Individually, the prognostic significance of high level of sPD-L1 expression was the highest in hepatic cell carcinoma (HR, 4.76; p<0.001) followed by gastric cancer (HR=3.55, p<0.001).

Conclusion

sPD-L1 may be a prognostic factor in DSCs for overall survival and disease-free survival. Inflammatory cytokines, treatment approaches, and other factors may affect the expression of sPD-L1. Therefore, the prognostic value of sPD-L1 for recurrence and metastasis should be further investigated. sPD-L1 may also predict response to treatment. Well-designed prospective studies with standard assessment methods should be conducted to determine the prognostic value of sPD-L1 in DSCs.

Soluble biomarkers to predict clinical outcomes in non-small cell lung cancer treated by immune checkpoints inhibitors

Lung cancer remains the first cause of cancer-related death despite many therapeutic innovations, including immune checkpoint inhibitors (ICI). ICI are now well used in daily practice at late metastatic stages and locally advanced stages after a chemo-radiation. ICI are also emerging in the peri-operative context. However, all patients do not benefit from ICI and even suffer from additional immune side effects. A current challenge remains to identify patients eligible for ICI and benefiting from these drugs. Currently, the prediction of ICI response is only supported by Programmed death-ligand 1 (PD-L1) tumor expression with perfectible results and limitations inherent to tumor-biopsy specimen analysis. Here, we reviewed alternative markers based on liquid biopsy and focused on the most promising biomarkers to modify clinical practice, including non-tumoral blood cell count such as absolute neutrophil counts, platelet to lymphocyte ratio, neutrophil to lymphocyte ratio, and derived neutrophil to lymphocyte ratio. We also discussed soluble-derived immune checkpoint-related products such as sPD-L1, circulating tumor cells (detection, count, and marker expression), and circulating tumor DNA-related products. Finally, we explored perspectives for liquid biopsies in the immune landscape and discussed how they could be implemented into lung cancer management with a potential biological-driven decision.

Clinical roles of soluble PD-1 and PD-L1 in plasma of NSCLC patients treated with immune checkpoint inhibitors

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have significantly improved the prognosis of non-small cell lung cancer (NSCLC). However, only a limited proportion of patients can benefit from this therapy, and clinically useful predictive biomarkers remain to be elucidated.

METHODS

Blood was collected from 189 patients with NSCLC before and six weeks after the initiation of ICI treatment (anti-PD-1 or anti-PD-L1 antibody). Soluble PD-1 (sPD-1) and PD-L1 (sPD-L1) in plasma before and after treatment were analyzed to evaluate their clinical significance.

RESULTS

Cox regression analysis demonstrated that higher sPD-L1 levels before treatment significantly predicted unfavorable progression-free survival (PFS; HR 15.4, 95% CI 1.10-86.7, P = 0.009) and overall survival (OS; HR 11.4, 95% CI 1.19-52.3, P = 0.007) in NSCLC patients treated with ICI monotherapy (n = 122) but not in those treated with ICIs combined with chemotherapy (n = 67: P = 0.729 and P = 0.155, respectively). In addition, higher sPD-1 levels after treatment were significantly associated with better OS (HR 0.24, 95% CI 0.06-0.91, P = 0.037) in patients treated with anti-PD-1 monotherapy, whereas higher sPD-L1 levels after treatment were significantly associated with worse PFS (HR 6.09, 95% CI 1.42-21.0, P = 0.008) and OS (HR 42.6, 95% CI 6.83-226, P < 0.001). The levels of sPD-L1 at baseline closely correlated with those of other soluble factors, such as sCD30, IL-2Ra, sTNF-R1, and sTNF-R2, which are known to be released from the cell surface by zinc-binding proteases ADAM10/17.

CONCLUSIONS

These findings suggest the clinical significance of pretreatment sPD-L1 as well as posttreatment sPD-1 and sPD-L1 in NSCLC patients treated with ICI monotherapy.

Serum immune mediators as novel predictors of response to anti-PD-1/PD-L1 therapy in non-small cell lung cancer patients with high tissue-PD-L1 expression

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related morbidity and mortality worldwide. Immune checkpoint inhibitors (ICIs) including anti-PD-1 and anti-PD-L1 antibodies, have significantly changed the treatment outcomes with better overall survival, but only 15-40% of the patients respond to ICIs therapy. The search for predictive biomarkers of responses is warranted for better clinical outcomes. We aim here to identify pre-treatment soluble immune molecules as surrogate biomarkers for tissue PD-L1 (TPD-L1) status and as predictors of response to anti-PD-1/PD-L1 therapy in NSCLC patients. Sera from 31 metastatic NSCLC patients, eligible for anti-PD-1/PD-L1 or combined chemoimmunotherapy, were collected prior to treatment. Analysis of soluble biomarkers with TPD-L1 status showed significant up/down regulation of the immune inhibitory checkpoint markers (sSiglec7, sSiglec9, sULBP4 and sPD-L2) in patients with higher TPD-L1 (TPD-L1 >50%) expression. Moreover, correlation analysis showed significant positive linear correlation of soluble PD-L1 (sPD-L1) with higher TPD-L1 expression. Interestingly, only responders in the TPD-L1 >50% group showed significant down regulation of the immune inhibitory markers (sPD-L2, sTIMD4, sNectin2 and CEA). When responders vs. non-responders were compared, significant down regulation of other immune inhibitory biomarkers (sCD80, sTIMD4 and CEA) was recorded only in responding patients. In this, the optimal cut-off values of CD80 <91.7 pg/ml and CEA <1614 pg/ml were found to be significantly associated with better progression free survival (PFS). Indeed, multivariate analysis identified the cutoff-value of CEA <1614 pg/ml as an independent predictor of response in our patients. We identified here novel immune inhibitory/stimulatory soluble mediators as potential surrogate/predictive biomarkers for TPD-L1 status, treatment response and PFS in NSCLC patients treated with anti-PD-1/PD-L1 therapy.

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.

Soluble programmed cell death ligand 1 predicts prognosis for gastric cancer patients treated with nivolumab: Blood-based biomarker analysis for the DELIVER trial

BACKGROUND

The clinical value of soluble forms of programmed cell death-1 (sPD-1), PD ligand 1 (sPD-L1) and cytotoxic T lymphocyte-associated protein-4 (sCTLA-4) for gastric cancer (GC) patients treated with nivolumab monotherapy has remained unknown.

METHODS

Blood samples collected before nivolumab treatment from 439 GC patients enrolled in the DELIVER (Japan Clinical Cancer Research Organisation GC-08) trial were analysed for sPD-1, sPD-L1 and sCTLA-4. Corresponding baseline clinical data were also retrieved.

RESULTS

Higher plasma levels of sPD-1 (hazard ratio [HR] = 1.27, p = 0.020), sPD-L1 (HR = 1.86, p < 0.001) and sCTLA-4 (HR = 1.33, p = 0.008) were significantly associated with shorter overall survival (OS), whereas only higher sPD-L1 levels was significantly associated with shorter progression-free survival (HR = 1.30, p = 0.008). The sPD-L1 concentration was significantly associated with the Glasgow prognostic score (GPS) (p < 0.001), but both sPD-L1 (HR = 1.67, p < 0.001) and GPS (HR = 1.39, p = 0.009 for GPS 0 versus 1; HR = 1.95, p < 0.001 for GPS 0 versus 2) were independently associated with OS. Patients with a GPS of 0 and low sPD-L1 thus showed the longest OS (median, 12.0 months) and those with a GPS of 2 and high sPD-L1 showed the shortest OS (median, 3.1 months), yielding a HR of 3.69 (p < 0.001).

CONCLUSION

Baseline sPD-L1 levels have the potential to predict survival for advanced GC patients treated with nivolumab, with the prognostic accuracy of sPD-L1 being improved by its combination with GPS.

Study of the clinicopathological features of soluble PD-L1 in lung cancer patients

Objective: In recent years, an association between serum soluble immune checkpoint molecules (sICMs) and malignant tumors has been reported, which may become important biomarkers in the future. Although several reports have suggested a correlation between sICMs and prognosis, their origin is unclear. In this study, changes in serum soluble PD-L1 (sPD-L1) during the perioperative period and its origin were analyzed in patients with lung cancer. Patients and Methods: Patients with lung tumors (n=39) were included. Samples for sPD-L1 measurements were collected at five time points before and after surgery, and their changes over time were analyzed. ELISA was used to measure sPD-L1 levels. Results: Thirty-nine patients with lung tumors (31, males; 8, females; age, 74 (years) ± 7.7 (range: 51-89) years; malignancy/benign, 33/6) were enrolled. Eight cases of driver gene mutation-positive tumors were included. Twenty-eight (72%) patients were smokers, and their performance status was 0-1 in all 39 patients. PD-L1 TPS was ≥50%/1-49%/<1% in 8/10/14 patients. Stage I/II/III/IV/postoperative recurrence of lung cancer was observed in 21/0/6/5/1 patients, respectively. There were no significant correlations between sPD-L1 levels and clinicopathological features and no correlation with PD-L1 TPS. Comparing localized lesions (stages I-III) with advanced lesions (stage IV and postoperative recurrence), the distribution of sPD-L1 was slightly higher in advanced lesions, although the difference was not significant. No obvious changes in sPD-L1 expression were observed before and after surgery. Conclusion: sPD-L1 levels tended to be high in stage III and above lung cancer. There was no change in sPD-L1 levels before and after surgery. sPD-L1 levels did not correlate with the PD-L1 TPS.

Soluble PD-L1 as a Prognostic Factor for Immunotherapy Treatment in Solid Tumors: Systematic Review and Meta-Analysis

Blocking the Programmed Cell Death Protein 1 (PD-1)/programmed death ligand-1 (PD-L1) axis has demonstrated great efficacy in cancer immunotherapy treatment and remains the central modality of immune targeting. To support the rational and tailored use of these drugs, it is important to identify reliable biomarkers related to survival. The role of the soluble form of the PD-L1 (sPD-L1) as a prognostic biomarker related to survival in solid cancer patients treated with immunotherapy has not yet been consistently evaluated. A systematic literature search of original articles in PubMed, MEDLINE and Scopus was conducted. Studies reporting hazard ratios (HRs) with a 95% confidence interval (CI) or Kaplan−Meier curves or individual patient data for overall survival (OS) or progression-free survival (PFS) associated with baseline levels of sPD-L1 in cancer patients undergoing immunotherapy treatment were considered eligible. Twelve studies involving 1076 patients and different tumor types treated with immunotherapy were included in the analysis. High blood levels of sPD-L1 correlated with poorer OS and PFS in cancer patients treated with immunotherapy (HR = 1.49, 95%CI: 1.15, 1.93, p < 0.01, I2 = 77% for OS; HR = 1.59, 95%CI: 1.20, 2.12, p < 0.01, I2 = 82% for PFS). A subgroup analysis highlighted that high levels of sPD-L1 were associated with worse survival in patients affected by NSCLC (HR = 1.81 95%CI: 1.09−3.00, p = 0.02, I2 = 83% for OS; HR = 2.18, 95%CI: 1.27−3.76, p < 0.01, I2 = 88% for PFS). An HR > 1 indicated that patients with low levels of sPD-L1 have the highest rates of OS/PFS. In this meta-analysis, we clarified the role of sPD-L1 in different solid cancers treated exclusively with Immune checkpoint inhibitors (ICIs). sPD-L1 could represent a non-invasive biomarker that is easily dosable in the blood of patients. The pooled data from the selected studies showed that a high circulating concentration of sPD-L1 in cancer patients correlates with worse survival, suggesting that it may be a helpful prognostic biomarker for the selection of cancer patients before immunotherapy, thus improving the efficacy of ICIs and avoiding unnecessary treatment.

Pre-treatment soluble PD-L1 as a predictor of overall survival for immune checkpoint inhibitor therapy: a systematic review and meta-analysis

Introduction

Immune checkpoint inhibitors (ICI) such as anti-PD-L1 and anti-PD-1 agents have been proven to be effective in various cancers. However, the rate of non-responders is still high in all cancer entities. Therefore, the identification of biomarkers that could help to optimize therapeutic decision-making is of great clinical importance. Soluble PD-L1 (sPD-L1) and PD-1 (sPD-1) are emerging blood-based biomarkers and were previously shown to be prognostic in various clinical studies.

Objective

We aimed to evaluate the prognostic relevance of sPD-L1 and sPD-1 in patients with different tumor entities who underwent ICI therapy.

Methods

We searched for articles in PubMed via Medline, Embase, Scopus, and Cochrane databases. The primary outcome was overall survival (OS) and progression-free survival (PFS); furthermore, we analyzed on-treatment serum level changes of sPD-L1 and sPD-1 during ICI therapy.

Results

We synthesized the data of 1,054 patients with different cancer types from 15 articles. Pooled univariate analysis showed that elevated levels of sPD-L1 were significantly associated with inferior OS (HR = 1.67; CI:1.26–2.23, I2 = 79%, p < 0.001). The strongest association was found in non-small cell lung cancer, whereas weaker or no association was observed in melanoma as well as in renal cell and esophageal cancers. Pooled multivariate analysis also showed that elevated levels of sPD-L1 correlated with worse OS (HR = 1.62; CI: 1.00–2.62, I2 = 84%, p = 0.05) and PFS (HR = 1.71; CI:1.00–2.94, I2 = 82%, p = 0.051). Furthermore, we observed that one or three months of anti-PD-L1 treatment caused a strong (27.67-fold) elevation of sPD-L1 levels in malignant mesothelioma and urothelial cancer.

Conclusions

We found significantly inferior OS in ICI-treated cancer patients with elevated pre-treatment sPD-L1 levels, but this association seems to be tumor type dependent. In addition, sPD-L1 increases during anti-PD-L1 therapy seems to be therapy specific.

Prognostic value of soluble programmed cell death ligand-1 in patients with non-small-cell lung cancer: a meta-analysis

Background: Previously published data was collected and a meta-analysis was conducted to precisely identify the prognostic and clinicopathological significance of soluble programmed cell death ligand-1 (sPD-L1) in patients with non-small-cell lung cancer (NSCLC). Materials & methods: Combined hazard ratios (HRs), odds ratios and 95% confidence intervals were used to assess the correlation between sPD-L1 expression and prognosis in patients with NSCLC. Results: A total of 11 studies with 976 patients were included in this meta-analysis. High levels of sPD-L1 were associated with poor overall and progression-free survival (HR: 2.65, 95% CI: 2.32-3.02; p < 0.001 vs HR: 2.02, 95% CI: 1.24-3.29; p = 0.005). sPD-L1 level was not significantly correlated with sex, smoking status, age, Eastern Cooperative Oncology Group performance status, subtype or EGFR mutation. Conclusion: High levels of sPD-L1 are a prognostic marker for poor survival in patients with NSCLC.

Biological Characteristics and Clinical Significance of Soluble PD-1/PD-L1 and Exosomal PD-L1 in Cancer

The immune checkpoint pathway consisting of the cell membrane-bound molecule programmed death protein 1 (PD-1) and its ligand PD-L1 has been found to mediate negative regulatory signals that effectively inhibit T-cell proliferation and function and impair antitumor immune responses. Considerable evidence suggests that the PD-1/PD-L1 pathway is responsible for tumor immune tolerance and immune escape. Blockage of this pathway has been found to reverse T lymphocyte depletion and restore antitumor immunity. Antagonists targeting this pathway have shown significant clinical activity in specific cancer types. Although originally identified as membrane-type molecules, several other forms of PD-1/PD-L1 have been detected in the blood of cancer patients, including soluble PD-1/PD-L1 (sPD-1/sPD-L1) and exosomal PD-L1 (exoPD-L1), increasing the composition and functional complications of the PD-1/PD-L1 signaling pathway. For example, sPD-1 has been shown to block the PD-1/PD-L immunosuppressive pathway by binding to PD-L1 and PD-L2, whereas the role of sPD-L1 and its mechanism of action in cancer remain unclear. In addition, many studies have investigated the roles of exoPD-L1 in immunosuppression, as a biomarker for tumor progression and as a predictive biomarker for response to immunotherapy. This review describes the molecular mechanisms underlying the generation of sPD-1/sPD-L1 and exoPD-L1, along with their biological activities and methods of detection. In addition, this review discusses the clinical importance of sPD-1/sPD-L1 and exoPD-L1 in cancer, including their predictive and prognostic roles and the effects of treatments that target these molecules.

A Dual-Channel Intelligent Point-of-Care Testing System for Soluble Programmed Death-1 and Programmed Death-Ligand 1 Detection Based on Folding Paper-Based Immunosensors

Both programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) are important proteins in cancer immunotherapy. Soluble forms (sPD-1 and sPD-L1) have potential for determining treatment and prognosis monitoring. However, there is a lack of detection methods for point-of-care testing (POCT) of these two proteins, so a low-cost rapid detection platform is urgently needed. To solve this problem, a dual-channel electrochemical platform, including a folding paper-based immunosensor and a POCT system for rapid simultaneous detection of these two proteins was designed and fabricated. The immunosensor consists of a three-electrode system and a reaction cell. The surface of the working electrode was modified with nanocomposites synthesized from amine-functionalized single-walled carbon nanotubes, new methylene blue, and gold nanoparticles. Antibodies to sPD-1 and sPD-L1 were also immobilized on the working electrode surface. A differential pulse voltammetry electrochemical method was adopted. The immunosensor was able to detect sPD-1 and sPD-L1 in the ranges of 50 pg/mL to 50 ng/mL and 5 pg/mL to 5 ng/mL, respectively. The limits of detection were 10 and 5 pg/mL. Using this detection platform, sPD-1 and sPD-L1 in plasma were detected by both enzyme-linked immunosorbent assay and the immunosensor, which has good application potential.

[Research Progress of Immunotherapy Biomarkers for Non-small Cell Lung Cancer]

Lung cancer is one of the most prevalent malignancies with the highest morbidity and mortality rates worldwide. In recent years, with the development of immune-oncology research and several therapeutic antibodies have reach the clinic, many breakthroughs have been made in immunotherapy. The advent of immunotherapy has revolutionized the treatment of NSCLC, but the response and durable clinical benefit are only observed in a small subset of patients. Therefore, strategies to screen the potential beneficial population and improve the efficacy of immunotherapy remain an essential topic. In the current article, the author review the biomarkers that have potential to better predict responders to immunotherapy and to provide ideas for the clinical application of immunotherapy.
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Prognostic Role of Soluble Programmed Death Ligand 1 in Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

OBJECTIVE

The objective of this study was to explore whether soluble programmed death ligand 1 (sPD-L1) is a potential prognostic biomarker in patients with non-small cell lung cancer (NSCLC).

METHODS

A comprehensive search of electronic databases was carried out. Original studies with inclusion of sPD-L1, progression-free survival, and overall survival in NSCLC were eligible. The primary endpoints were overall survival and progression-free survival. Hazard ratios (HRs) and 95% confidence intervals (CIs) were applied for data analysis.

RESULTS

Eight studies involving 710 patients with NSCLC were included in the analysis. A pooled data analysis revealed that high levels of sPD-L1 were correlated with poorer overall survival (HR = 2.34; 95% CI = 1.82-3.00; P < 0.001) and progression-free survival (HR = 2.35; 95% CI = 1.62-3.40, P < 0.001). A subgroup analysis revealed that high levels of sPD-L1 were correlated with poor overall survival in patients treated with immunotherapy (HR = 2.40; 95% CI = 1.79-3.22; P < 0.001).

CONCLUSION

This pooled analysis of published data suggests that sPD-L1 may serve as a readily available biomarker for survival in NSCLC patients treated with ICI based treatment. Prospective studies with well-designed standard assessment methods should be conducted to validate the prognostic role of sPD-L1 in NSCLC.

SYSTEMATIC REVIEW REGISTRATION

https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021283177.

Soluble PD-L1 as a predictive biomarker in lung cancer: a systematic review and meta-analysis

Background: We performed a meta-analysis to evaluate the association between soluble PD-L1 (sPD-L1) and survival outcomes and treatment response in lung cancer. Methods & methods: Eligible studies were obtained by searching PubMed, EMBASE and Web of Science. Pooled effect estimates were calculated for overall survival (OS), progression-free survival (PFS) and objective response rate (ORR). Results: Twelve eligible studies with 1188 lung cancer patients were included. High sPD-L1 was significantly associated with worse OS (hazard ratio [HR] = 2.20; 95% CI: 1.59-3.05; p < 0.001) and PFS (HR = 2.42; 95% CI: 1.72-3.42; p < 0.001) in patients treated with immune checkpoint inhibitors (ICIs). Meanwhile, high sPD-L1 predicted worse OS (HR = 1.60; 95% CI: 1.31-1.96; p < 0.001) and lower ORR (odds ratio = 0.52; 95% CI: 0.35-0.80; p = 0.002) in patients treated with non-ICI therapies. Conclusion: sPD-L1 is a potential predictive biomarker of lung cancer.

Soluble Programmed Death Ligand-1 (sPD-L1): A Pool of Circulating Proteins Implicated in Health and Diseases

Upon T-cell receptor stimulation, the Programmed cell Death-1 receptor (PD-1) expressed on T-cells can interact with its ligand PD-L1 expressed at the surface of cancer cells or antigen-presenting cells. Monoclonal antibodies targeting PD-1 or PD-L1 are routinely used for the treatment of cancers, but their clinical efficacy varies largely across the variety of tumor types. A part of the variability is linked to the existence of several forms of PD-L1, either expressed on the plasma membrane (mPD-L1), at the surface of secreted cellular exosomes (exoPD-L1), in cell nuclei (nPD-L1), or as a circulating, soluble protein (sPD-L1). Here, we have reviewed the different origins and roles of sPD-L1 in humans to highlight the biochemical and functional heterogeneity of the soluble protein. sPD-L1 isoforms can be generated essentially by two non-exclusive processes: (i) proteolysis of m/exoPD-L1 by metalloproteases, such as metalloproteinases (MMP) and A disintegrin and metalloproteases (ADAM), which are capable of shedding membrane PD-L1 to release an active soluble form, and (ii) the alternative splicing of PD-L1 pre-mRNA, leading in some cases to the release of sPD-L1 protein isoforms lacking the transmembrane domain. The expression and secretion of sPD-L1 have been observed in a large variety of pathologies, well beyond cancer, notably in different pulmonary diseases, chronic inflammatory and autoimmune disorders, and viral diseases. The expression and role of sPD-L1 during pregnancy are also evoked. The structural heterogeneity of sPD-L1 proteins, and associated functional/cellular plurality, should be kept in mind when considering sPD-L1 as a biomarker or as a drug target. The membrane, exosomal and soluble forms of PD-L1 are all integral parts of the highly dynamic PD-1/PD-L1 signaling pathway, essential for immune-tolerance or immune-escape.

Kynurenine/Tryptophan Ratio as a Potential Blood-Based Biomarker in Non-Small Cell Lung Cancer

The enzyme indoleamine 2,3-dioxygenase 1 (IDO1) degrade tryptophan (Trp) into kynurenine (Kyn) at the initial step of an enzymatic pathway affecting T cell proliferation. IDO1 is highly expressed in various cancer types and associated with poor prognosis. Nevertheless, the serum Kyn/Trp concentration ratio has been suggested as a marker of cancer-associated immune suppression. We measured Kyn and Trp in blood samples of a wide cohort of non-small-cell lung cancer (NSCLC) patients, before they underwent surgery, and analyzed possible correlations of the Kyn/Trp ratio with either IDO1 expression or clinical–pathological parameters. Low Kyn/Trp significantly correlated with low IDO1 expression and never-smoker patients; while high Kyn/Trp was significantly associated with older (≥68 years) patients, advanced tumor stage, and squamous cell carcinoma (Sqcc), rather than the adenocarcinoma (Adc) histotype. Moreover, high Kyn/Trp was associated, among the Adc group, with higher tumor stages (II and III), and, among the Sqcc group, with a high density of tumor-infiltrating lymphocytes. A trend correlating the high Kyn/Trp ratio with the probability of recurrences from NSCLC was also found. In conclusion, high serum Kyn/Trp ratio, associated with clinical and histopathological parameters, may serve as a serum biomarker to optimize risk stratification and therapy of NSCLC patients.

Epstein-Barr Virus LMP1 Induces Soluble PD-L1 in Nasopharyngeal Carcinoma

Nasopharyngeal carcinoma (NPC) is an Epstein–Barr virus (EBV)-associated malignancy. The principal oncogene of EBV, latent membrane protein 1 (LMP1), induces the expression of programmed death-ligand 1 (PD-L1), which is an immunosuppressive transmembrane protein and a promising therapeutic target for various malignancies. Recent studies have revealed an association between the level of soluble PD-L1 (sPD-L1) and disease progression. However, the role of sPD-L1 in NPC or its relevance to LMP1 has not been elucidated. This study aimed to examine whether LMP1 induces sPD-L1 in vitro and analyze the clinical relevance of LMP1, PD-L1, and sPD-L1 in NPC patients. Analysis of nasopharyngeal cell lines revealed that LMP1 induces both cellular PD-L1 and sPD-L1. Analysis of biopsy specimens from 32 NPC patients revealed that LMP1 expression was significantly correlated with PD-L1 expression. Finally, the serum sPD-L1 level in NPC patients was higher than that in the controls. Moreover, the sPD-L1 level in the advanced stage was higher than that in the early stage. However, LMP1 expression, PD-L1 expression, and sPD-L1 levels were not associated with prognosis. These results suggest that LMP1 induces both sPD-L1 and PD-L1, which are associated with NPC progression.