Tumor PD-L1 Expression Research Articles

Oncolytic vaccinia virus immunotherapy antagonizes image-guided radiotherapy in mouse mammary tumor models.

Ionizing radiation (IR) and oncolytic viruses are both used to treat cancer, and the effectiveness of both agents depends upon stimulating an immune response against the tumor. In this study we tested whether combining image guided ionizing radiation (IG-IR) with an oncolytic vaccinia virus (VACV) could yield a better therapeutic response than either treatment alone. ΔF4LΔJ2R VACV grew well on irradiated human and mouse breast cancer cells, and the virus can be combined with 4 or 8 Gy of IR to kill cells in an additive or weakly synergistic manner. To test efficacy in vivo we used immune competent mice bearing orthotopic TUBO mammary tumors. IG-IR worked well with 10 Gy producing 80% complete responses, but this was halved when the tumors were treated with VACV starting 2 days after IG-IR. VACV monotherapy was ineffective in this model. The antagonism was time dependent as waiting for 21 days after IG-IR eliminated the inhibitory effect but without yielding any further benefits over IR alone. In irradiated tumors, VACV replication was also lower, suggesting that irradiation created an environment that did not support infection as well in vivo as in vitro. A study of how four different treatment regimens affected the immune composition of the tumor microenvironment showed that treating irradiated tumors with VACV altered the immunological profiles in tumors exposed to IR or VACV alone. We detected more PD-1 and PD-L1 expression in tumors exposed to IR+VACV but adding an αPD-1 antibody to the protocol did not change the way VACV interferes with IG-IR therapy. VACV encodes many immunosuppressive gene products that may interfere with the ability of radiotherapy to induce an effective anti-tumor immune response through the release of danger-associated molecular patterns. These data suggest that infecting irradiated tumors with VACV, too soon after exposure, may interfere in the innate and linked adaptive immune responses that are triggered by radiotherapy to achieve a beneficial impact.

A Brief Report of Durvalumab With or Without Tremelimumab in Combination With Chemotherapy as First-Line Therapy for Metastatic Non-Small-Cell Lung Cancer: Outcomes by Tumor PD-L1 Expression in the Phase 3 POSEIDON Study

IntroductionIn the phase 3 POSEIDON study, first-line tremelimumab plus durvalumab and platinum-based chemotherapy (T+D+CT) significantly improved overall survival (OS; hazard ratio [HR] 0.77 [95% confidence interval {CI} 0.65–0.92]; P=.0030) and progression-free survival (PFS) versus chemotherapy alone (CT) in patients with metastatic NSCLC (mNSCLC), leading to approval for this regimen. We report outcomes by programmed cell death ligand-1 (PD-L1) tumor cell (TC) expression level. MethodsPatients with EGFR/ALK wild-type mNSCLC were randomized (1:1:1) to T+D+CT, durvalumab plus chemotherapy (D+CT), or CT with stratification by PD-L1 expression (TC ≥50% vs <50%), disease stage, and histology. In this post-hoc exploratory analysis, OS, PFS, objective response rate, duration of response, and safety were assessed in subgroups with PD-L1 TC ≥1% versus <1%. ResultsAmong 1012/1013 randomized patients with known PD-L1 status, 644 (63.6%) versus 368 (36.4%) had TC ≥1% versus <1%. T+D+CT numerically improved (HR [95% CI]) OS (TC ≥1%, 0.76 [0.61–0.95]; <1%, 0.77 [0.58–1.00]) and PFS (TC ≥1%, 0.68 [0.54–0.85]; <1%, 0.78 [0.59–1.03]) versus CT in both subgroups. D+CT showed numerical OS improvement versus CT in the TC ≥1% subgroup (0.79 [0.64–0.98]) but not the <1% subgroup (0.99 [0.76–1.30]), with similar PFS results. Safety in both subgroups was consistent with the overall population. ConclusionsThis exploratory analysis supports T+D+CT as a first-line treatment option for patients with mNSCLC irrespective of PD-L1 expression, including the harder-to-treat subgroup with PD-L1 TC <1%, consistent with the role of cytotoxic T-lymphocyte-associated antigen 4 and PD-L1 in the immune response.

Integrating molecular subtype and CD8+ T cells infiltration to predict treatment response and survival in muscle-invasive bladder cancer

BackgroundLuminal and Basal are the primary intrinsic subtypes of muscle-invasive bladder cancer (MIBC). The presence of CD8+ T cells infiltration holds significant immunological relevance, potentially influencing the efficacy of antitumor responses. This study aims to synergize the influence of molecular subtypes and CD8+ T cells infiltration in MIBC.MethodsThis study included 889 patients with MIBC from Zhongshan Hospital, The Cancer Genome Atlas, IMvigor210 and NCT03179943 cohorts. We classified the patients into four distinct groups, based on the interplay of molecular subtypes and CD8+ T cells and probed into the clinical implications of these subgroups in MIBC.ResultsAmong patients with Luminal-CD8+Thigh tumors, the confluence of elevated tumor mutational burden and PD-L1 expression correlated with a heightened potential for positive responses to immunotherapy. In contrast, patients featured by Luminal-CD8+Tlow displayed a proclivity for deriving clinical advantages from innovative targeted interventions. The Basal-CD8+Tlow subgroup exhibited the least favorable three-year overall survival outcome, whereas their Basal-CD8+Thigh counterparts exhibited a heightened responsiveness to chemotherapy.ConclusionsWe emphasized the significant role of immune-molecular subtypes in shaping therapeutic approaches for MIBC. This insight establishes a foundation to refine the process of selecting subtype-specific treatments, thereby advancing personalized interventions for patients.

Tumor immune microenvironment in odontogenic carcinomas: Evaluation of the therapeutic potential of immune checkpoint blockade.

Despite recent advances in the use of immune checkpoint blockade (ICB) across various cancer types, its efficacy in odontogenic carcinomas remains unexplored. This study aims to investigate PD-L1 expression and the tumor immune microenvironment (TIME) in odontogenic carcinomas to determine the therapeutic potential of ICB and the significance of immune markers. The expressions of PD-L1 and T cell markers (CD3, CD8, and FOXP3) were visualized by immunohistochemistry in 21 tissue samples of odontogenic carcinomas. Tumoral PD-L1 expression and the density and spatial distribution of T cell subsets were evaluated, from which TIME was determined. The associations of the variables with clinicopathological and prognostic factors were statistically analyzed. PD-L1 was positively expressed in 52.4% (11/21) of the cases studied. Among tumor types, ameloblastic carcinoma showed significantly higher PD-L1 expression (p = 0.016). TIME based on the intratumoral and stromal T cell distribution was immune-inflamed in 61.9% (13/21) and immune-excluded in 38.1% (8/21), with no immune-desert cases. PD-L1 expression was associated with the densities of all intratumoral T cell subsets (p = 0.03 for CD3, p = 0.03 for CD8, and p = 0.008 for FOXP3) but not with those of stromal T cells. High PD-L1 expression was associated with larger tumor size (p = 0.021), while the intratumoral CD8/CD3 ratio was inversely correlated with tumor size (p = 0.048). These findings indicate the involvement of adaptive immune resistance in a subset of odontogenic carcinomas and support the therapeutic potential of ICB in patients with these rare malignancies.

Efficacy and safety of cadonilimab in previously treated recurrent or metastatic nasopharyngeal carcinoma(COMPASSION-06): A phase II multicenter study

ObjectiveThis study was designed to assess the efficacy and safety of cadonilimab monotherapy, a first-in-class, bi-specific PD-1/CTLA-4 antibody, in patients with previously treated recurrent or metastatic nasopharyngeal carcinoma (R/M−NPC). Patients and MethodsThis multicenter, open-label, single-arm, phase II clinical trial enrolled patients with R/M−NPC who had failed first-line platinum-based chemotherapy and second-line single agent or combined chemotherapy, and immunotherapy-naive. Patients received cadonilimab for 6 mg/kg once every 2 weeks (Q2W). The primary endpoint was objective response rate (ORR) in full analysis set (FAS) assessed by investigators according to RECIST v.1.1. The secondary endpoint included progression-free survival (PFS), overall survival (OS), duration of response (DoR), time to response (TTR) and safety. ResultsA total of 23 patients were assessed. The median time from first dose to data cutoff was 16.56 (range, 0.8–25.2) months. ORR was 26.1 % (95 %CI:10.2–48.4). The ORR were 44.4 % (95 %CI: 13.7–78.8) and 14.3 % (95 %CI:1.8–42.8) in patients with tumor PD-L1 expression ≥50 % and <50 %, respectively. ORR was achieved in 40.0 % (95 %CI:12.2–73.8) of patients with EBV-DNA level <4000 IU/ml (n = 10) and 15.4 % (95 %CI:1.9–45.4) of those with ≥4000 IU/ml. The median PFS was 3.71 months (95 %CI: 1.84–9.30). respectively. Median OS was not reached, and the 12-month OS rate was 79.7 % (95 % CI:54.5–91.9). Only two patients (8.3 %) experienced Grade ≥3 treatment-related adverse events (TRAEs) with hypothyroidism (30.4 %), rash (21.7 %) and pruritus (21.7 %) being the most prevalent TRAEs. ConclusionCadonilimab monotherapy demonstrated a promising efficacy and manageable toxicity in patients with previously treated R-M/NPC and provide an efficacious salvage treatment option.

Heterogeneity of molecular subtyping and therapy-related marker expression in primary tumors and paired lymph node metastases of small cell lung cancer.

The classification of molecular subtypes and the identification of targetable molecules have been proposed for small cell lung cancer (SCLC) patients. Our aim was to investigate whether the expression of these markers evaluated using lymph node (LN) metastases represents that of primary tumors. We enrolled 46 surgically resected SCLC patients' primary tumors and paired mediastinal LN metastases. The protein expression of subtype-defining markers (ASCL1, NEUROD1, POU2F3, and YAP1) and therapeutic markers (DLL3, MYC, PD-L1, and MHC I) was examined by immunohistochemistry and was correlated with clinicopathological parameters and prognoses. In primary and metastatic tumors, the expression of these markers was 78.3% and 87.0%, 50.0% and 63.0%, 13.0% and 6.5%, 17.4% and 15.2%, 84.8% and 87.0%, 17.4% and 6.5%, 50.0% and 34.8%, and 60.9% and 37.0%, respectively. Positive tumor PD-L1 expression was less present in LN metastases (p = 0.015), and the same was true for MHC I expression (p = 0.036). NEUROD1 and DLL3 expression levels in metastatic tumors were stronger (p < 0.001 and p = 0.002, respectively); conversely, POU2F3, MYC, PD-L1, and MHC I expression levels were weaker (p = 0.018, p = 0.019, p = 0.001, and p < 0.001, respectively). In 15 (32.6%) patients, we observed a change in the molecular subtyping pattern, and a higher number of neuroendocrine (NE)-high phenotype patients were diagnosed when using the LN specimens (91.3% vs. 84.8%). TNM stage and postoperative chemotherapy were independent prognostic factors in surgically resected SCLC patients, and no prognostic differences were found among molecular subtypes. This study highlights the discordance of subtype-specific proteins and therapeutic markers between SCLC primary tumors and LN metastases. Additionally, our findings have therapeutic and prognostic implications and warrant further clinical investigation.

Momordicine-I Suppresses Head and Neck Cancer Growth by Reprogrammimg Immunosuppressive Effect of the Tumor-Infiltrating Macrophages and B Lymphocytes.

Head and neck cancer (HNC) is prevalent worldwide, and treatment options are limited. Momordicine-I (M-I), a natural component from bitter melon, shows antitumor activity against these cancers, but its mechanism of action, especially in the tumor microenvironment (TME), remains unclear. In this study, we establish that M-I reduces HNC tumor growth in two different immunocompetent mouse models using MOC2 and SCC VII cells. We demonstrate that the anticancer activity results from modulating several molecules in the monocyte/macrophage clusters in CD45+ populations in MOC2 tumors by single-cell RNA sequencing. Tumor-associated macrophages (TAM) often pose a barrier to antitumor effects, but following M-I treatment, we observe a significant reduction in the expression of Sfln4, a myeloid cell differentiation factor, and Cxcl3, a neutrophil chemoattractant, in the monocyte/macrophage populations. We further find that the macrophages must be in close contact with the tumor cells to inhibit Sfln4 and Cxcl3, suggesting that these TAMs are impacted by M-I treatment. Coculturing macrophages with tumor cells shows inhibition of Agr1 expression following M-I treatment, which is indicative of switching from M2 to M1 phenotype. Furthermore, the total B-cell population in M-I-treated tumors is significantly lower, whereas spleen cells also show similar results when cocultured with MOC2 cells. M-I treatment also inhibits PD1, PD-L1, and FoxP3 expression in tumors. Collectively, these results uncover the potential mechanism of M-I by modulating immune cells, and this new insight can help to develop M-I as a promising candidate to treat HNCs, either alone or as adjuvant therapy.

Estimating the impact of adjuvant treatment with nivolumab on long-term survivorship rates compared with surveillance: Analyses of disease-free survival (DFS) from the phase 3 CheckMate-274 trial.

528 Background: Durable DFS and cure are the ultimate goals for the treatment of muscle invasive urothelial carcinoma (MIUC) with radical cystectomy. This analysis employed mixture cure models (MCMs) to estimate the underlying cure fraction among high-risk MIUC patients following radical resection in the Phase 3 CheckMate-274 study. Methods: MCMs were applied to patient-level DFS data from the trial (minimum follow-up: 31.6 months). Intention-to-treat (ITT) population and the subpopulation with tumor PD-L1 expression ≥1% were analyzed separately for nivolumab (NIVO) and placebo (PBO) arms. In MCMs, the patient populations were assumed to consist of two exclusive subgroups as cured and uncured. Cured subgroup was assumed to be free of disease recurrence and disease-related mortality risks. The uncured subgroup was at the risk of both disease recurrence and all-cause mortality. DFS for the cured subgroup was estimated using background mortality rates published by WHO matched to the trial’s demographic characteristics. DFS for the uncured subgroup was modelled using parametric distributions, which were characterized along with the cure fraction by maximum likelihood methods. Model selection was primarily based on clinical plausibility of estimated DFS for the uncured subgroup. Visual comparison of the fits from the MCMs to the reported DFS data from the trial and goodness-of-fit statistics also assisted model selection. Results: In the trial, 353 patients were treated with NIVO (mean age: 65.3; male: 75.1%; PD-L1≥1%: 39.7%) and 356 patients were in PBO control (mean age: 65.9; male: 77.2%; PD-L1≥1%: 39.9%). Selected models estimated almost all uncured patients to experience recurrence within 5 years. The estimated cure fraction in the ITT population ranged from 43.1%-45.1% in the NIVO arm (95% CI: 36.7%-51.6%), and 36.4%-37.0% in the PBO arm, (95% CI: 30.9%-43.0%) for clinically plausible models. Projected range of 10-year mean DFS for the ITT patients was 4.38-4.47 years in the NIVO arm and 3.61-3.64 years in the PBO arm. Estimated cure fractions in the PD-L1≥1% subpopulation ranged from 59.1%-61.0% in the NIVO arm (95% CI: 48.9%-72.0%), and 35.9%-36.9% in the PBO arm, (95% CI: 27.5%-45.9%). Projected range of 10-year mean DFS for the PD-L1≥1% subpopulation was 5.54-5.65 years in the NIVO arm and 3.54-3.57 years in the PBO arm. Conclusions: In the adjuvant treatment of MIUC, relative to radical resection only, systemic therapy with NIVO is associated with a 6-9 percentage points higher cure fraction in the ITT population. Tumor PD-L1≥1% expression was associated with higher cure fractions in the NIVO arm but had only negligible impact on the underlying cure fraction in the PBO arm. Clinical trial information: NCT02632409 .

Four-year clinical update and treatment switching-adjusted outcomes with first-line nivolumab plus ipilimumab with chemotherapy for metastatic non-small cell lung cancer in the CheckMate 9LA randomized trial

BackgroundIn CheckMate 9LA, nivolumab plus ipilimumab with chemotherapy prolonged overall survival (OS) versus chemotherapy regardless of tumor PD-L1 expression or histology. We report updated efficacy and safety in all randomized...

HHLA2 is more significantly associated with poor prognosis in TSCC than PD-L1.

The incidence and mortality of tongue squamous cell carcinoma have shown an alarming increase in recent years. This study aimed to investigate the potential of HHLA2 as an immune checkpoint in comparison to PD-L1. We obtained RNA-seq data from TCGA to study HHLA2 and PD-L1 expression across various tissues. Using the CIBERSORT package, we estimated cell type abundances within mixed populations based on gene expression profiles. Immunohistochemistry was performed to analyze HHLA2 and PD-L1 expression in Tongue squamous cell carcinoma. Prognostic evaluation was carried out with Kaplan-Meier curves and the log-rank test. To explore factors affecting HHLA2, univariate and multivariate Cox regression analyses were conducted with the COX regression model. Additionally, we used single-cell RNA sequencing data from the GEO database for gene set enrichment analysis with genes strongly correlated with HHLA2. Our analysis of RNA-seq data unveiled a significant upregulation of HHLA2 and PD-L1 expression in primary tumors when compared with normal tissue. HHLA2 exhibited a positive expression rate of 36.9%, while PD-L1 had a positive expression rate of 24.6%. HHLA2 emerged as a noteworthy independent risk factor impacting the overall survival of Tongue squamous cell carcinoma patients. The analysis of scRNA-seq data shed light on the involvement of HHLA2 in key pathways related to cell cycle regulation and interferon alpha/beta signaling. This study suggests that in the context of Tongue squamous cell carcinoma, HHLA2 may represent a more promising target for immunotherapy when compared with PD-L1.

HER2 and PD-L1 immunohistochemistry (IHC) expression, and HER2 genomic alterations: Associations and clinical outcomes for advanced bladder cancer.

538 Background: Bladder cancer (BC) has a relatively high rate of human epidermal growth factor receptor 2 (HER2) alterations. The association between HER2 mutation/amplification, HER2, and PD-L1 immunohistochemistry (IHC) expression and associations with clinical outcomes for advanced bladder cancer (BC) has not been studied. Methods: We retrospectively analyzed BC samples for PD-L1 and HER2 IHC expression and compared HER2 alterations from genomic profiling with the MSK IMPACT platform. HER2 IHC expression was defined as 0, 1+, 2+, 3+, and PD-L1 IHC was the combined tumor and immune cell PD-L1 expression score (CPS). HER2 alteration was defined as either pathogenic mutation and/or amplification. We studied pairwise associations between HER2 alteration, PD-L1, and HER2 IHC expression in all patients and their associations with progression-free survival (PFS) and overall survival (OS) for muscle-invasive bladder cancer (MIBC) pts. Association analyses were performed using the Wilcoxon rank-sum test or Fisher’s exact test. Kaplan-Meier method and Cox proportional hazard models were used for time-to-event analyses. Results: Among 202 pts with HER2 IHC, 188 had MSK IMPACT, and 168 had PD-L1 CPS. The overall incidence of HER2 alteration was 22.3%; 48.2% had CPS ³10, and HER2 IHC distribution was 0:18.8%, 1+:29.7%, 2+:33.7%, and 3+:17.8%. The CPS score was inversely associated with HER2 IHC expression (p&lt;0.001). No association was noted between CPS score and HER2 alteration (p=0.735). HER2 altered tumors were strongly correlated with high-level HER2 IHC expression (p&lt;0.001). However, 41% (n=14/34) of HER2 IHC 3+ samples did not have HER2 alterations, and 17% (n=7/36) of HER2 altered samples had HER2 IHC expression of 0. In patients with MIBC, HER2 alteration and HER2 IHC expression (0/1+ vs. 2+/3+) were not associated with PFS (p=0.5 and p=0.4, respectively) or OS for MIBC pts (p=0.84 and p=0.94, respectively). A higher PD-L1 CPS score (&gt;=10 vs &lt;10) was associated with improved PFS for MIBC pts (p=0.03). Conclusions: Our study is the first to describe an inverse correlation between HER2 IHC expression and PD-L1 CPS score. Furthermore, HER2 IHC overexpression is strongly associated with HER2 amplification, but a subset of patients with high HER2 protein expression are potentially missed by genomic profiling alone. HER2 expression by IHC or HER2 genomic alteration is not a prognostic marker for MIBC pts in this cohort. This data provides the foundation for further HER2-directed advanced BC studies. [Table: see text]

Comparison of Tumor Non-specific and PD-L1 Specific Imaging by Near-Infrared Fluorescence/Cerenkov Luminescence Dual-Modality In-situ Imaging.

Labeled antibodies are excellent imaging agents in oncology to non-invasively visualize cancer-related antigens expression levels. However, tumor tracer uptake (TTU) of specific antibodies in-vivo may be inferior to non-specific IgG in some cases. To explore factors affecting labeled antibody visualization by PD-L1 specific and non-specific imaging of nude mouse tumors. TTU was observed in RKO model on Cerenkov luminescence (CL) and near-infrared fluorescence (NIRF) imaging of radionuclide 131I or NIRF dyes labeled Atezolizumab and IgG. A mixture of NIRF dyes labeled Atezolizumab and 131I-labeled IgG was injected, and TTU was observed in the RKO and HCT8 model by NIRF/CL dual-modality in-situ imaging. TTU were observed by 131I-labeled Atezolizumab and IgG in-vitro distribution. Labeled IgG concentrated more in tumors than Atezolizumab. NIRF/CL imaging in 24 to 168 h showed that TTU gradually decreased over time, which decreased more slowly on CL imaging compared to NIRF imaging. The distribution data in-vitro showed that TTU of 131I-labeled IgG was higher than that of 131I-labeled Atezolizumab at any time point. Non-specific IgG may not be suitable as a control for Atezolizumab in comparing tumor PD-L1 expression in nude mice via labeled antibody optical imaging under certain circumstances.

Comparing Three Different Anti–Programmed Death-Ligand 1 Antibodies in Immunohistochemical Evaluation of Combined Chemoimmunotherapy Response in Patients With NSCLC: A Prospective Study

IntroductionMultiple programmed death-ligand 1 (PD-L1) immunohistochemistry assays performed using different antibodies including DAKO 22C3, DAKO 28-8, and Ventana SP142 PD-L1—predictive markers for response to various immune checkpoint inhibitors in NSCLC—have been approved in several countries. The differences in multiple PD-L1 immunohistochemistry assay results in predicting the therapeutic response to combined chemoimmunotherapy in patients with NSCLC remain unclear. MethodsIn this multicenter prospective observational study, we monitored 70 patients with advanced NSCLC treated with combined chemoimmunotherapy at 10 institutions in Japan. The expression of PD-L1 in pretreatment tumors was evaluated using the 22C3, 28-8, and SP142 assays in all patients. ResultsThe PD-L1 level in tumor cells determined using the 22C3 assay was the highest among the three assays performed with different antibodies. According to the 22C3 assay results, the PD-L1 tumor proportion score greater than or equal to 50% group had a significantly longer progression-free survival period than the PD-L1 tumor proportion score less than 50% group. Nevertheless, the other assays did not reveal remarkable differences in the objective response rate or progression-free survival. ConclusionsIn our study, PD-L1 expression determined using the 22C3 assay was more correlated with the therapeutic response of patients with NSCLC treated with combined chemoimmunotherapy than that determined using the 28-8 and SP142 assays. Therefore, the 22C3 assay may be useful for clinical decision-making for patients with NSCLC treated with combined chemoimmunotherapy. Trial registration number: UMIN 000043958.

Tumor characteristics of dissociated response to immune checkpoint inhibition in advanced melanoma

IntroductionImmune checkpoint inhibition (ICI) has improved patients’ outcomes in advanced melanoma, often resulting in durable response. However, not all patients have durable responses and the patients with dissociated response are a valuable subgroup to identify mechanisms of ICI resistance.MethodsStage IV melanoma patients treated with ICI and dissociated response were retrospectively screened for available samples containing sufficient tumor at least at two time-points. Included were one patient with metachronous regressive and progressive lesions at the same site, two patients with regressive and novel lesion at different sites, and three patients with regressive and progressive lesions at different sites. In addition, four patients with acquired resistant tumor samples without a matched second sample were included.ResultsIn the majority of patients, the progressive tumor lesion contained higher CD8+ T cell counts/mm2 and interferon-gamma (IFNγ) signature level, but similar tumor PD-L1 expression. The tumor mutational burden levels were in 2 out 3 lesions higher compared to the corresponding regressive tumors lesion.In the acquired tumor lesions, high CD8+/mm2 and relatively high IFNγ signature levels were observed. In one patient in both the B2M and PTEN gene a stop gaining mutation and in another patient a pathogenic POLE mutation were found.ConclusionIntrapatient comparison of progressive versus regressive lesions indicates no defect in tumor T cell infiltration, and in general no tumor immune exclusion were observed.

Correlation between stromal Th and Tc lymphocytes and PD-L1 expression in early breast cancer tumors.

Prognostic and predictive value of PD-L1 as a biomarker in breast cancer remains controversial. While some studies suggest its association with negative prognostic parameters, others reported a highly significant association between PD-L1 expression and tumor-infiltrating lymphocytes, which are known to be an independent favorable prognostic factor. The aim of present study is to examine the relationship between immune response markers and PD-L1 expression in early breast cancer. Immunohistochemical expression of PD-L1, along with density and composition of stromal lymphocytic infiltrate and peritumoral lymphoid aggregates was analyzed in 95 samples of invasive breast cancer. A strong positive correlation between PD-L1 expression and the density of stromal lymphocytic infiltrate and peritumoral lymphoid aggregates was identified and a cut-off value of 53% coverage of tumor stroma by lymphocytes, with which PD-L1 positivity can be predicted with excellent diagnostic accuracy, was determined for the first time using statistical methods. Additionally, PD-L1 positivity was observed significantly more often in tumors with higher absolute number of both CD4 and CD8 T-lymphocytes in the stromal infiltrate. No significant correlation with molecular subtype of breast cancer was found. Our results indicate that the density of stromal lymphocytic infiltrate might be a better predictor of PD-L1 positivity in early breast cancer than the molecular subtype and that the key to the optimization of PD-L1 as a biomarker in breast cancer lies in its interpretation in the context of other immune response markers.

Circ_0007422 Knockdown Inhibits Tumor Property and Immune Escape of Colorectal Cancer by Decreasing PDL1 Expression in a miR-1256-Dependent Manner.

Circular RNAs (circRNAs) are a group of important molecules involved in the progression of various cancers, including colorectal cancer (CRC). Here, we aim to investigate the role and molecular mechanism of circ_0007422 in regulating CRC malignant progression. The expression levels of circ_0007422, miR-1256, and PDL1 were detected by qRT-PCR. Cell viability, proliferation, apoptosis, invasion, and self-replication ability were analyzed by CCK-8, EdU, flow cytometry, transwell, and spheroid formation experiments, respectively. Protein levels were determined by western blotting assay. CRC cells were co-cultured with CD8 + T cells, phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMCs), or cytokine-induced killer (CIK) cells in vitro, and CD8 + T-cell apoptosis, IFN-γ and TNF-α levels, and survival rate of CRC cells were analyzed to reveal the role of circ_0007422 in antitumor immunity. The relationship between miR-1256 and circ_0007422 or PDL1 was identified by a dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay. A xenograft tumor model was established to verify the function of circ_0007422 in tumor growth in vivo. Immunohistochemistry (IHC) assay was used to detect positive expression rates of Ki67, E-cadherin, N-cadherin, and PDL1 expression in primary tumors from CRC cells. Circ_0007422 was upregulated in CRC tissues and cells and its knockdown inhibited proliferation, invasion, self-replication ability, and immune escape and promoted apoptosis of CRC cells. Additionally, circ_0007422 bound to miR-1256, which was identified to target PDL1. MiR-1256 inhibition reversed the effects of circ_0007422 knockdown on the tumor properties and immune escape of CRC cells. Moreover, miR-1256 introduction interacted with PDL1 to suppress proliferation, invasion, self-replication ability, and immune escape and promote apoptosis of CRC cells. Further, circ_0007422 knockdown hampered tumorigenesis of CRC cells in vivo. Circ_0007422 knockdown inhibited tumor property and immune escape of colorectal cancer through the miR-1256/PDL1 pathway, providing a potential novel therapeutic target for CRC.

Exploratory analysis of biomarkers of response to durvalumab in advanced HER2-negative oesophago-gastric adenocarcinoma within a phase 2 clinical trial.

384 Background: Advanced oesophago-gastric cancers have showcased varied responses to immunotherapy based on biomarkers such as tumour mutational burden, microsatellite instability, and PD-L1 expression. However, these markers may not fully capture tumour heterogeneity and evolutionary dynamics. Hence, understanding the intricate relationship between immune selection, specifically immune dN/dS,1 and tumour evolution is vital for devising personalized therapeutic strategies. Methods: In our phase 2 open label, multicentre, randomised PLATFORM trial (NCT02678182), patients received maintenance durvalumab post first-line chemotherapy. A survival advantage was not seen with maintenance durvalumab compared to surveillance and exploratory analysis of PD-L1 expression was not associated with improved survival outcomes.2 However, a subset of patients treated with durvalumab experienced durable responses and some experienced incremental radiological responses. A pilot substudy on a selected cohort (n=24) of these patients was designed to explore the potential of immunogenomics evolutionary-based metrics, notably dN/dS, as predictive biomarkers. DNA and RNA from FFPE baseline tumour samples underwent analysis, examining genomic factors including tumour mutational burden, indel signatures, PDL1 status, and immune evasion mechanisms. Furthermore, the evolutionary metric, immune dN/dS, which has implications in tumour immunoediting and its response to immunotherapies, was scrutinized. Results: A dominant indel mutational signature emerged from the analysis. The majority of patients displayed a significantly higher number of indel variants, compared to non-synonymous and synonymous single-nucleotide variants. A recurring observation was dN/dS values consistently above 1, indicating positive selection for non-synonymous somatic variants. Additionally, hypermutation in driver genes, notably TP53 and XIRP2, was detected. One patient, with a unique dN/dS &lt; 1, showcased survival beyond four years without liver metastases. Immune dN/dS &gt; 1 and no evidence of liver metastases displayed the best prognosis after treatment in contrast with those that have immune dN/dS &lt; 1 with or without liver metastases. Conclusions: Immune dN/dS emerges as a promising tool to decode tumour evolutionary mechanisms, providing profound insights into the dynamics of tumour evolution in advanced HER2 negative oesophago-gastric cancer patients receiving durvalumab immunotherapy. This pilot study underscores the potential of this novel immunogenomic approach in improving patient stratification and tailoring therapeutic strategies in cancer immunotherapy. 1. Zapata et al, Nature Genetics, 2023. 2. Fong et al, J Clin Oncol, 2021. Clinical trial information: NCT02678182 .

DNA mismatch repair system regulates the expression of PD-L1 through DNMTs in cervical cancer

BackgroundCervical cancer (CC) is a potential clinical application of PD-1/PD-L1 inhibitor. We aimed to study the mechanism of DNA mismatch repair (MMR) system regulating the expression of PD-L1 in CC through DNA methyltransferase (DNMTs).MethodsWe collected pathological specimens from 118 cases of CC to analyze the relationship between PD-L1 expression and DNMTs in different MMR states. RNA interference (RNAi) technique was used to simulate the formation of CC cell line with MMR deficiency (dMMR) state, and subcutaneous tumor formation experiment was carried out in nude mice to verify the relationship between PD-L1 expression and DNMTs in MMR state.ResultsThe PD-L1 positive rate in 118 cases of CC was 58.47%, while the microsatellite instability (MSI) status accounted for 5.93%. There was a significant difference in the expression of PD-L1 between patients within the dMMR and MMR proficient (pMMR) groups (χ2 = 21.405, P < 0.001). Subcutaneous inoculation after infection of Siha cells led to successful tumorigenesis in nude mice, accompanied by a significant increase in the level of PD-L1 expression in the mouse tumors, while the expression level of MLH1 and MSH2 protein decreased significantly. We also found that PD-L1 expression was closely related to the expression of DNMTs.ConclusionPD-L1 is universal expressed on the surface of CC cells, dMMR status enhances the expression of PD-L1 on the surface of CC cells, dMMR states of CC are related to the demethylation status of the PD-L1 gene promoter region.

Molecular epidemiology study of programmed death ligand 1 and ligand 2 protein expression assessed by immunohistochemistry in extensive-stage small-cell lung cancer.

Prevalence of tumor PD-L1 expression in extensive-stage small-cell lung cancer (ES-SCLC) is variable, and data on PD-L2 expression are limited. The prognostic values of these biomarkers are not well understood. The current study was conducted to address these data gaps. A retrospective cohort study of Danish patients with histologically confirmed ES-SCLC and evaluable tumor samples who were receiving usual care before the introduction of immunotherapy was conducted. Protein expression of PD-L1 and PD-L2 was determined by immunohistochemistry (IHC) using the PD-L1 IHC 22C3 pharmDx assay and a PD-L2 IHC assay using a propriety mouse monoclonal antibody. A combined positive score (CPS) of ≥1 was used to define biomarker positivity. Kaplan-Meier plots and Cox proportional hazard models were employed to assess the relationship between PD-L1 and PD-L2 protein expression and OS. Among 80 patients, 31% (n=25) and 36% (n=29) had disease positive for PD-L1 and PD-L2, respectively. Overall, 85% (n=68) of patients had concordant PD-L1/PD-L2 status; 26% (n=21) had double positive disease (both PD-L1 and PD-L2 CPS ≥1) and 59% (n=47) had double negative disease (both PD-L1 and PD-L2 CPS <1). PD-L1 and PD-L2 positivity were each associated with longer OS (unadjusted hazard ratios [HRs], 0.35 [95% CI, 0.21-0.61] and 0.50 [95% CI, 0.31-0.82]); the associations persisted after adjustment for several known prognostic factors (HRs, 0.41 [95% CI, 0.22-0.75] and 0.44 [95% CI, 0.25-0.79] for PD-L1 and PD-L2 positivity, respectively). When evaluating OS in patients with double positive disease, unadjusted and adjusted HRs for double positive compared with double negative were similar to those with only PD-L1 or PD-L2 positivity (unadjusted HR, 0.36 [95% CI, 0.20-0.64]; adjusted HR, 0.36 [0.18-0.73]). PD-L1 and PD-L2 positivity were observed in approximately one-third of assessed ES-SCLC tumor samples and were highly congruent. Patients with PD-L1 and PD-L2 positivity, alone or combined, were associated with longer OS, independent of other prognostic factors.

Characterization of immunomodulating agents from Staphylococcus aureus for priming immunotherapy in triple-negative breast cancers

Immunotherapy, specifically immune checkpoint blockade (ICB), has revolutionized the treatment paradigm of triple-negative breast cancers (TNBCs). However, a subset of TNBCs devoid of tumor-infiltrating T cells (TILs) or PD-L1 expression generally has a poor response to immunotherapy. In this study, we aimed to sensitize TNBCs to ICB by harnessing the immunomodulating potential of S. aureus, a breast-resident bacterium. We show that intratumoral injection of spent culture media from S. aureus recruits TILs and suppresses tumor growth in a preclinical TNBC model. We further demonstrate that α-hemolysin (HLA), an S. aureus-produced molecule, increases the levels of CD8+ T cells and PD-L1 expression in tumors, delays tumor growth, and triggers tumor necrosis. Mechanistically, while tumor cells treated with HLA display Gasdermin E (GSDME) cleavage and a cellular phenotype resembling pyroptosis, splenic T cells incubated with HLA lead to selective expansion of CD8+ T cells. Notably, intratumoral HLA injection prior to ICB augments the therapeutic efficacy compared to ICB alone. This study uncovers novel immunomodulatory properties of HLA and suggests that intratumoral administration of HLA could be a potential priming strategy to expand the population of TNBC patients who may respond to ICB.