Low PD-L1 Expression Research Articles

An immune suppressive tumor microenvironment in primary prostate cancer promotes tumor immune escape.

Immunotherapy has demonstrated limited activity in prostate cancer to date. This likely reflects an immune suppressive tumor microenvironment (TME), with previous studies suggesting low PD-L1 expression and a sparse immune cell infiltrate. We aimed to further characterise the immune TME in primary prostate cancer and correlate immune subset densities with clinical outcomes. Two distinct cohorts of patients treated with radical prostatectomy were identified, based on the development of biochemical recurrence (BCR), one subgroup with high International Society of Urological Pathologists (ISUP) grade group, recurrent disease and a second with low grade, non-recurrent disease. A prostate immunohistochemical (IHC) antibody cocktail was used to differentiate tumor and peritumoral benign tissue. Specific CD8+, CD4+, FoxP3+, CD20+ and CD68+ cell subsets were identified using IHC staining of consecutive slides. PD-L1 and CD8/PD-L1 dual staining were also performed. Cell subset densities were quantified within tumor and peritumoral regions. We used descriptive statistics to report cell subset densities and T-tests to compare groups by age, grade and the development of BCR. Univariable and multivariable logistic regression were used to analyse risk factors for BCR and the development of metastatic disease. A total of 175 patients were included, with a median age of 63 years and median pre-operative PSA of 8.2ng/ml. BCR occurred in 115 patients (66%) and 56 (32%) developed metastatic disease. CD68+ cells were the most abundant (median 648.8/mm2 intratumoral, 247.6/mm2 peritumoral), while PD-L1+ and PD-L1/CD8+ cell density was low overall (PD-L1+ median 162.4/mm2 intratumoral, 141.7/mm2 peritumoral; PD-L1/CD8+ (median 5.52/mm2 intratumoral, 3.41/mm2 peritumoral). Overall, grade group and T-stage were independently associated with BCR and metastatic disease. Higher density of peritumoral PD-L1+ cells was an independent risk factor for BCR (OR 5.33, 95%CI 1.31-21.61, p = 0.019).Although higher densities of CD8+ and CD4+ cells were observed in higher grade group 3-5 tumors, these were not associated with the development of BCR or metastasis. In our cohort of prostate cancer patients who underwent radical prostatectomy, higher grade group and T-stage were independent predictors of BCR and metastasis. Despite higher grade group being associated with higher CD8+ cell density, PD-L1+ and PD-L1/CD8+ cell densities were low overall, suggesting lower T cell receptor recognition of tumor antigens. Further understanding of this phenomenon would influence development of future immunotherapeutic strategies in prostate cancer.

Long-term outcomes among patients who respond within the first year to nivolumab plus ipilimumab or nivolumab monotherapy: A pooled analysis in 935 patients

PurposeTo investigate the predictive value of RECIST response within 3, 6, or 12 months on long-term survival, and explore differences between nivolumab+ipilimumab and nivolumab monotherapy, we analyzed pooled 5-year data of 935 responder and non-responder patients at various time points after treatment initiation in CheckMate 069, 066, and 067 studies. Patients and methodsTreatment-naive advanced melanoma patients received nivolumab+ipilimumab or nivolumab monotherapy. To decrease immortal time bias, 3-, 6-, or 12-month overall survival (OS) and progression-free survival (PFS) landmark analyses were performed. Association between characteristics and response was evaluated by univariate and multivariate analyses. ResultsResponse rates at any time were 58 % (239/409) for nivolumab+ipilimumab and 44 % (230/526) for nivolumab monotherapy. In 12-month landmark analyses, 5-year OS rates for responders versus non-responders were 82 % versus 40 % with nivolumab+ipilimumab (HR=0.23 [95 % CI, 0.15–0.35]) and 76 % versus 32 % with nivolumab monotherapy (HR=0.22 [95 % CI, 0.16–0.31]). PFS rates were 83 % versus 32 % and 69 % versus 46 %, respectively. Similar strong associations between response at 3 and 6 months and 5-year OS and PFS were also observed with more than 70 % of the responses observed in the first 3 months. Response rates correlated with baseline LDH and PD-L1 status by multivariate analysis but the association between response and long-term survival was maintained in landmark analyses even among patients with high LDH and low PD-L1 expression. ConclusionClinical response evaluated in the first months of therapy is a strong predictor of long-term survival, even in patients with poor prognostic biomarkers.

Spatially Resolved Whole-Transcriptomic and Proteomic Profiling of Lung Cancer and Its Immune Microenvironment According to PD-L1 Expression.

The expression of PD-L1 on tumor cells (TC) is used as an immunotherapy biomarker in lung cancer, but heterogeneous intratumoral expression is often observed. To better understand heterogeneity in the lung cancer tumor microenvironment, we performed proteomic and whole-transcriptomic digital spatial profiling analyses of TCs and immune cells (IC) in spatially matched areas based on tumor PD-L1 expression and the status of the immune microenvironment. We validated our findings using IHC, data from The Cancer Genome Atlas, and immunotherapy cohorts. ICs in areas with high PD-L1 expression on TCs showed more features, indicative of immunosuppression and exhaustion, than ICs in areas with low PD-L1 expression on TCs. TCs highly expressing PD-L1 within immune-inflamed areas showed upregulation of proinflammatory processes, whereas TCs highly expressing PD-L1 within immune-deficient areas showed upregulation of various metabolic processes. Using differentially expressed genes of TCs between the immune-inflamed and immune-deficient areas, we identified a prognostic gene signature for lung cancer. In addition, we found that a high ratio of CD8+ cells to M2 macrophages predicted favorable outcomes in patients with PD-L1-expressing lung cancer after immune checkpoint inhibitor therapy. Overall, this study demonstrates that TCs and ICs have distinct spatial features within the lung tumor microenvironment that are related to tumor PD-L1 expression and IC infiltration.

TROPION-Lung07: Phase III study of Dato-DXd+pembrolizumab±platinum-based chemotherapy as 1L therapy for advanced non-small-cell lung cancer.

For patients with advanced/metastatic non-small-cell lung cancer (NSCLC) without actionable genomic alterations and low (<50%) PD-L1 expression, pembrolizumab plus pemetrexed and platinum chemotherapy is a preferred first-line treatment. These patients have comparatively worse outcomes than those with higher PD-L1 expression, underscoring the need for new combination strategies. Datopotamab deruxtecan (Dato-DXd), a TROP2-directed antibody-drug conjugate, has demonstrated encouraging antitumor activity and safety in this patient population. We describe the rationale and design of TROPION-Lung07, a randomized, open-label Phase III study assessing Dato-DXd in combination with pembrolizumab with/without platinum-based chemotherapy versus pembrolizumab plus pemetrexed and platinum-based chemotherapy in patients with advanced/metastatic non-squamous NSCLC without actionable genomic alterations and <50% PD-L1 expression. Primary study objectives are progression-free survival and overall survival.Clinical Trial Registration: NCT05555732 (ClinicalTrials.gov).

Low PD-L1 expression, MAP2K2 alterations, and enriched HPV gene signatures characterize brain metastases in head and neck squamous cell carcinoma

BackgroundBrain metastasis (BM) is a rare but severe complication of head and neck squamous cell carcinoma (HNSCC), with limited knowledge of molecular characteristics and immunogenicity.MethodsWe analyzed 61 cases of HNSCC-BM from three academic institutions (n = 24) and Foundation Medicine Inc (FMI, n = 37). A subset of cases underwent next-generation sequencing, multiple immunofluorescence, and proximity ligation sequencing. Gene enrichment analysis compared alterations in FMI BM samples (n = 37) with local samples (n = 4082).ResultsDemographics included: median age of 59 years, 75% male, 55% current/former smokers, 75% oropharyngeal primary, and 67% human papillomavirus (HPV) +. ATM (54%), KMT2A (54%), PTEN (46%), RB1 (46%), and TP53 (46%) were frequently altered in BM samples from academic centers (62% HPV/p16+). Structural rearrangements ranged from 9 to 90 variants by proximity ligation sequencing. BMs had low densities of CD8+, PD-1+, PD-L1+, and FOXP3 + cells, and 92% had PD-L1 combined positive scores < 1%. CDKN2A (40.5%), TP53 (37.8%), and PIK3CA (27.0%) alterations were common in the FMI BMs (51% HPV+). MAP2K2 alterations and HPV + signature were enriched in FMI BMs compared to local tumors (11.8% vs. 6.4%, P = 0.005 and 51.25% vs. 26.11%, P = 0.001 respectively), and pathogenic TSC1 inactivating mutations were enriched in local tumors (67.3% vs. 37.8%, P = 0.008). Median overall survival from BM diagnosis was 9 months (range 0–27).ConclusionsHNSCC patients with BM frequently have oropharyngeal primary sites and are HPV+. Common molecular alterations in BM samples, including targetable PIK3CA and ATM, were identified. MAP2K2 alterations were enriched and densities of immune cells were low, highlighting potential targets for further research and immunotherapy considerations.

The prognostic and therapeutic value of the tumor microenvironment and immune checkpoints in pancreatic neuroendocrine neoplasms

Pancreatic neuroendocrine neoplasms (Pan-NEN) represent a group of highly heterogeneous cancers, characterized by complex and diverse biological behavior. The objective of this study was to systematically investigate the immunological features of the tumor microenvironment (TME) in Pan-NEN, aiming to identify prognostic biomarkers and explore the therapeutic potential of immunotherapy for Pan-NEN. Tumor and adjacent normal tissues were collected from 56 patients with Pan-NEN. Immunohistochemical analysis was conducted on tumor tissues using a panel of monoclonal antibodies targeting key immune markers. The expression levels of these markers were quantitatively assessed and correlated with clinicopathological features and overall survival. Low expression of CD3, CD8, CD4, CD68, CD163, Foxp3, CD56, CD69, GZMB, HLA-1, HLA-II, PD-1, and PD-L1 were observed in the majority of Pan-NEN patient samples. PD-1 expression was positively correlated with CD4 and Foxp3 expression, while PD-L1 expression was positively correlated with CD68, CD163, and Foxp3 expression; HLA-II expression was positively correlated with GZMB expression. Infiltration of lymphocytes (CD3 + or CD8+) and macrophages (CD68 + or CD163+) and expression of PD-1/PD-L1 were more pronounced in poorly differentiated neuroendocrine carcinoma (Pan-NEC) compared to well-differentiated neuroendocrine tumors (Pan-NET), while CD68 and PD-L1 correlated with advanced disease stage. Conversely, HLA-I antigen expression was commonly downregulated in Pan-NEC. Univariate Cox proportional hazard analysis demonstrated that tumor grade, stage; CD4+, CD68+, and CD163 + cell count; and expression of PD-1 and PD-L1 were significantly associated with poor survival outcomes, while the positive expression of HLA-I was correlated with a more favorable survival prognosis. Furthermore, multivariate Cox proportional hazard analyses revealed that tumor grade, stage, and PD-1 expression are independent prognostic factors. The immunological landscape of Pan-NEN offers potential prognostic value and therapeutic targets. The findings suggest that immunotherapy, particularly targeting the PD-1/PD-L1 pathway, may serve as a promising strategy for the treatment of Pan-NEN, especially for Pan-NEC patients.

Prognostic and Predictive Capabilities of Tumor-Infiltrating Lymphocytes in Breast Cancer

The aim of the study is to evaluate the prognostic and predictive capabilities of tumorinfiltrating lymphocytes in breast cancer (BC); to study the prognostic value of T-cell (CD8+, CD3+) lymphocyte infiltration of the tumor and the level of T-regulatory (CD4+) lymphocytes; to study the prognostic and predictive value of the expression of proteins Forkhead Box Protein 3, check-point PD-1, PDL1. Materials and methods. The content of tumor-infiltrating lymphocytes and their quantitative ratio and correlation with regulatory genes were assessed. Archival material was used in the work. The study included archival data from the cancer registry of 1240 patients treated at the N.N. Petrov Cancer Research Institute from 2000 to 2009. Histological preparations stained with hematoxylin and eosin were scanned. Ten-year relapse-free and overall survival were assessed. Results. About 80% of patients with BC have low levels of tumor infiltration by CD8+ cytotoxic T lymphocytes and CD3+ lymphocytes. Expression of the PD-L1 gene was detected more often (29.5%) in triple-negative breast cancer, 1.5 times less often (18.2%) in HER2+ BC and extremely rarely (1.5%) in luminal A subtype. Severe (more than 10%) lymphocytic infiltration of CD8+ and CD3+ with low expression of PD-L1 and FOXP3 improves relapse-free and overall survival of patients with BC. Conclusion. The inclusion of lymphocytic infiltration of the tumor as a prognostic biomarker represents an important step in understanding the biology of BC.

Multi-Functional AIE Phototheranostic Agent Enhancing αPD-L1 Response for Oral Squamous Cell Carcinoma Immunotherapy.

Oral squamous cell carcinoma (OSCC) represents a prevalent head and neck malignancy with surgical intervention as the primary clinical option. Immunotherapy, particularly immune checkpoint blockade (ICB) targeting PD-1/PD-L1 shows great promise but is impeded by the immunosuppressive tumor microenvironment and low PD-L1 expression in OSCC. Herein, the "all-in-one" phototherapeutic nanoparticles (TSD NPs) are reported with balanced reactive oxygen species and photothermal conversion capacity for combined photoimmunotherapy and ICB immunotherapy against OSCC. A novel electron acceptor, 3-(dicyanomethylene)-2,3-dihydrobenzothiophene-1,1-dioxide (DTM), is introduced to develop the phototherapeutic agent with aggregation-induced emission (AIE) feature and NIR-II fluorescence centered at 1000nm. Benefiting from the AIE feature and the DTM acceptor, the resultant TSD NPs also exhibit strong type I reactive oxygen species (ROS) generation and high photothermal conversion efficiency (45.3%), which can profoundly induce immunogenic cell death (ICD), activate cytotoxic T lymphocytes, and convert the immunosuppressive tumor microenvironment into an immune-supportive one. Additionally, TSD NPs upregulate the PD-L1 expression on OSCC cells, thus enhancing the efficacy of combined treatment with αPD-L1 ICB immunotherapy. This results show that the synergistic treatment of TSD NPs and αPD-L1 effectively eradicates solid OSCC tumors without adverse effects on normal tissues, proving a novel and promising strategy for OSCC management.

Prognostic Impact of Bone Metastasis in Patients With Metastatic Urothelial Carcinoma Treated With Durvalumab With or Without Tremelimumab in the DANUBE Study

Background and ObjectiveBone metastases (BM) in metastatic urothelial carcinoma (mUC) may impact patient outcomes, but their independent effect with immune checkpoint inhibitors (ICIs) is uncertain. We aimed to assess the impact of BM and PD-L1 status on outcomes in mUC patients treated with ICIs. MethodsThis post hoc analysis of the DANUBE study included 1032 mUC patients treated with durvalumab (D), D + tremelimumab (T), or standard chemotherapy (SoC). Patients were categorized by BM status and assessed for median overall survival (mOS) and median progression-free survival (mPFS) stratified by PD-L1 expression and treatment arm. Key Findings and LimitationsAmong all patients enrolled in the study, those with BM had a lower mOS than those with no BM (8.7 vs. 15.8 months; P < .0001). Patients with BM and high PD-L1 expression, treated with D or D + T, had numerically longer mOS than patients with BM and low PD-L1 expression. In contrast, in the chemotherapy arm, there was no difference in mOS for BM or no BM, based on PD-L1 expression. Patients with BM had shorter mPFS compared to no BM (2.6 vs. 5.4 months; P < .0001). The study is limited by its post hoc nature. Conclusions and Clinical ImplicationsPresence of BM was associated with worse outcomes across treatment arms. Patients with BM and high PD-L1 expression treated with D or D + T had longer mOS, suggesting potential benefits of ICIs in this subgroup. Consideration of BM and PD-L1 status in treatment decisions for mUC patients receiving ICIs may improve clinical outcomes. Plain English SummaryWe investigated the impact of bone metastases in patients with advanced bladder cancer treated with immune therapy. Patients with bone metastases had shorter survival times compared to those without. However, patients with high levels of a specific marker in their tumors had better outcomes with immune therapy. Understanding these factors could help doctors make better treatment decisions for patients with bladder cancer.

Real-world effectiveness and safety of recombinant human endostatin plus PD-1 inhibitors and chemotherapy as first-line treatment for EGFR/ALK-negative, advanced or metastatic non-small cell lung cancer

BackgroundThis study aimed to evaluate the effectiveness and safety of recombinant human endostatin (Rh-endostatin) plus programmed cell death 1 (PD-1) inhibitors and chemotherapy as first-line treatment for advanced or metastatic non-small cell lung cancer (NSCLC) in a real-world setting.MethodsThis was a retrospective study on patients with EGFR/ALK-negative, advanced or metastatic NSCLC. Patients received Rh-endostatin plus PD-1 inhibitors and chemotherapy every three weeks for 4 to 6 cycles. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), and safety.ResultsA total of 68 patients were included in this retrospective analysis. As of data cutoff (December 13, 2022), the median follow-up of 21.4 months (interquartile range [IQR], 8.3-44.4 months). The median PFS and OS was 22.0 (95% confidence interval [CI]: 16.6-27.4) and 31.0 months (95% CI: 23.4-not evaluable [NE]), respectively. The ORR was 72.06% (95% CI: 59.85-82.27%), and DCR was 95.59% (95% CI: 87.64-99.08%). Patients with stage IIIB/IIIC NSCLC had significantly longer median PFS (23.4 vs. 13.2 months), longer median OS (not reached vs. 18.0 months), and higher ORR (89.2% vs. 51.6%) than those with stage IV NSCLC (all p ≤ 0.001). The ORR was higher in patients with high PD-L1 expression (tumor proportion score [TPS] ≥ 50%) than in those with low PD-L1 expression or positive PD-L1 expression (75% vs. 50%, p = 0.025). All patients experienced treatment-related adverse events (TRAEs), and ≥ grade 3 TRAEs occurred in 16 (23.53%) patients.ConclusionsRh-endostatin combined with PD-1 inhibitors plus chemotherapy as first-line treatment yielded favorable effectiveness with a manageable profile in patients with advanced or metastatic NSCLC, representing a promising treatment modality.

VISTA Emerges as a Promising Target against Immune Evasion Mechanisms in Medulloblastoma.

Relapsed medulloblastoma (MB) poses a significant therapeutic challenge due to its highly immunosuppressive tumor microenvironment. Immune checkpoint inhibitors (ICIs) have struggled to mitigate this challenge, largely due to low T-cell infiltration and minimal PD-L1 expression. Identifying the mechanisms driving low T-cell infiltration is crucial for developing more effective immunotherapies. We utilize a syngeneic mouse model to investigate the tumor immune microenvironment of MB and compare our findings to transcriptomic and proteomic data from human MB. Flow cytometry reveals a notable presence of CD45hi/CD11bhi macrophage-like and CD45int/CD11bint microglia-like tumor-associated macrophages (TAMs), alongside regulatory T-cells (Tregs), expressing high levels of the inhibitory checkpoint molecule VISTA. Compared to sham control mice, the CD45hi/CD11bhi compartment significantly expands in tumor-bearing mice and exhibits a myeloid-specific signature composed of VISTA, CD80, PD-L1, CTLA-4, MHCII, CD40, and CD68. These findings are corroborated by proteomic and transcriptomic analyses of human MB samples. Immunohistochemistry highlights an abundance of VISTA-expressing myeloid cells clustering at the tumor-cerebellar border, while T-cells are scarce and express FOXP3. Additionally, tumor cells exhibit immunosuppressive properties, inhibiting CD4 T-cell proliferation in vitro. Identification of VISTA's binding partner, VSIG8, on tumor cells, and its correlation with increased VISTA expression in human transcriptomic analyses suggests a potential therapeutic target. This study underscores the multifaceted mechanisms of immune evasion in MB and highlights the therapeutic potential of targeting the VISTA-VSIG axis to enhance anti-tumor responses.

Evaluating Safety and Clinical Activity of Front-line Treatment with Cadonilimab plus Chemotherapy in Advanced/Metastatic Nonsmall Cell Lung Cancer Harboring STK11 Genetic Aberration: A Protocol of Phase II Study

BackgroundCadonilimab is a first-in-class bispecific PD-1/CTLA-4 antibody. Serine/threonine kinase (STK11) mutation was shown to be related to low PD-L1 expression and objective response rate (ORR) in nonsmall cell lung cancer (NSCLC), resulting in poor progression-free survival (PFS) and overall survival (OS). Herein, we hypothesized that combining cadonilimab with chemotherapy could enhance antitumor immunity and extend survival in these patients. Consequently, we designed this study to explore the clinical activity and safety of cadonilimab combined with chemotherapy in patients with advanced/metastatic NSCLC harboring STK11 alteration. Trial designThis single-center, open-label, single-arm phase II trial is conducted at the first affiliated hospital of Guangzhou Medical University. Treatment-naïve advanced/metastatic NSCLC patients harboring STK11 mutation will be enrolled in this study. Eligible patients will receive either cadonilimab (10mg/kg on Day 1) plus pemetrexed (500 mg/m2) and carboplatin (AUC = 5) for nonsquamous NSCLC or abraxane (100 mg/m2) and carboplatin (AUC = 5) for squamous NSCLC for 4 cycles, followed by maintenance therapy (cadonilimab plus pemetrexed or abraxane). The treatment will be discontinued when disease progression, intolerability to cadonilimab, and/or chemotherapy occurs. Measurable lesions were assessed according to the Response Evaluation Criteria in Solid Tumors (1.1). The main endpoint is ORR and safety. Subordinate endpoints include PFS, disease control rate, and duration of response. ResultsThe study commenced enrolment in September 2023, with preliminary findings regarding the primary endpoint anticipated by January 2025.

Evolving Precision First-Line Systemic Treatment for Patients with Unresectable Non-Small Cell Lung Cancer.

First-line systemic therapy for patients with advanced or metastatic non-small cell lung cancer (NSCLC) has rapidly evolved over the past two decades. First, molecularly targeted therapy for a growing number of gain-of-function molecular targets has been shown to improve progression-free survival (PFS) and overall survival (OS) with favorable toxicity profiles compared to platinum-containing chemotherapy and can be given as first-line systemic therapy in ~25% of patients with NSCLC. Actionable genetic alterations include EGFR, BRAF V600E, and MET exon 14 splicing site-sensitizing mutations, as well as ALK-, ROS1-, RET-, and NTRK-gene fusions. Secondly, inhibitors of programmed cell death protein 1 or its ligand 1 (PD-1/L1) such as pembrolizumab, atezolizumab, or cemiplimab monotherapy have become a standard of care for ~25% of patients with NSCLC whose tumors have high PD-L1 expression (total proportion score (TPS) ≥50%) and no sensitizing EGFR/ALK alterations. Lastly, for the remaining ~50% of patients who are fit and whose tumors have no or low PD-L1 expression (TPS of 0-49%) and no sensitizing EGFR/ALK aberrations, platinum-containing chemotherapy with the addition of a PD-1/L1 inhibitor alone or in combination of a cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) inhibitor improves PFS and OS compared to chemotherapy alone. The objectives of this review are to summarize the current data and perspectives on first-line systemic treatment in patients with unresectable NSCLC and propose a practical algorithm for implementing precision biomarker testing at diagnosis.

PD-L1 and PD-L2 Expression in Different Tumor Stages and Types of Malignant Salivary Gland Neoplasms: A Single-center Experience.

There is a limited amount of data on the role of programmed cell death ligand (PD-L) -1 and PD-L2 in salivary gland carcinomas. We aimed to evaluate the prognostic value of PD-L1 and PD-L2 expressions, which are closely related to immune mechanisms, with respect to salivary gland tumor types and stages. Data from patients with salivary gland masses surgically removed between 2006 and 2021, diagnosed with a malignant salivary gland neoplasm, were retrospectively analyzed. Immunoreactivity for PD-L1 and PD-L2 was performed on resection materials. The mean age of 90 patients was 52.1±18.8 and 46.7% were male. Overall, 55.6% of patients were diagnosed with adenoid cystic carcinoma (ACC), 23.3% with mucoepidermoid carcinoma (MEC), 16.7% with acinic cell carcinoma (AciCC), 3.3% with ductal carcinoma (DC), and 1 patient with pleomorphic adenoma ex carcinoma (PA-ex-CA). In all, 52% of ACC, 12% of AciCC, 24% of MEC, and 12% of DC cases were at stage IV. The tumor diameter, frequencies of lymphovascular invasion, metastasis, positive surgical margin, recurrence, and mortality rates of patients at stages III and IV were significantly larger than those at stages I and II ( P <0.05). The percentages of tumor cell score (TCS) and immune cell score (ICS) for PD-L1 were significantly higher among patients with MEC compared with those with other types of tumors ( P =0.0011). However, the percentages of combined score (CS) for PD-L1 and tumor cell score for PD-L2 were comparable among tumor types ( P >0.05). No significant difference was found in these scores for PD-L1 between tumor stages ( P >0.05), but for PD-L2, all patients at stage I had TCS <1% for PD-L2, while all patients at stages II and III, and 92% of patients at stage IV had TCS ≥1% ( P <0.0001). High expression of PD-L1 was mostly observed in MEC cases ( P =0.0016), while all patients with AciCC had a low PD-L1 expression level ( P =0.0206). The mean tumor diameter, rate of lymphovascular invasion, perineural invasion, metastasis, positive surgical margin, recurrence, type of treatment, mortality, and TILs ratio did not differ significantly according to PD-L1 expression level ( P >0.05). The percentage of tumor-infiltrating lymphocytes was comparable among negative and positive PD-L1 scores according to both 1% and 5% threshold values ( P >0.05). High PD-L1 expression is rare in AciCC, while PD-L1 expression is high in MEC. Our findings underline the importance of future screening for PD-L1 and PD-L2 before patients undergoing immunotherapies in all salivary gland tumors.

Response to first-line therapies in metastatic lung adenocarcinoma with low PD-L1 expression: A multi-center retrospective study.

e20574 Background: For metastatic lung adenocarcinoma with low PD-L1 expression (tumor proportion score:1-49%), chemotherapy in combination with immune checkpoint inhibitors (IC), with bevacizumab (BC), or with both (IBC) have been established as standard first-line options. However, the optimal scheme is still undetermined. Methods: This retrospective study enrolled 125 metastatic lung adenocarcinoma patients with low PD-L1 expression from four cancer centers. All the patients received IC, BC, or IBC as the first-line therapies. Propensity score matching (PSM) with a ratio of 1:1:1 was used to balance the inter-group clinical characteristics. Efficacy, including objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS) and overall survival (OS), as well as safety were evaluated. Results: 35 of the 125 patients received IBC, 37 received BC, and 53 received IC. After PSM, a total of 35 pairs of patients were enrolled in the analysis. Patients receiving IBC (ORR: 57.1%, DCR:100%) or IC (ORR: 57.1%, DCR: 91.4%) obtained superior ORR and DCR in relative to those receiving BC (ORR: 45.7%, DCR: 82.9%). However, only IBC (median PFS: 20.47m; median OS: not research) rather than IC (median PFS: 10.0m; median OS: 21.36m) treatment generated significantly prolonged PFS and OS compared with BC (median PFS: 9.43m, P = 0.007; median OS: 23.2m, P = 0.048). We further analyzed the survival benefit based on different clinical and molecular features. We found patients with female gender had more significant OS benefit from IBC treatment over IC or BC treatment. In addition, non-smokers benefit more from IBC compared with IC. The occurrence of adverse events (AEs) was more frequent in IBC (74.3%) and IC (85.7%) group in relative to BC group (42.8%). Meanwhile, ≥ grade 3 AEs (22.9%) was markedly higher in IBC group compared with that in BC group (5.7%). However, leukopenia and neutropenia represent the most common ≥ grade 3 AEs, which are easy to be clinically managed. Conclusions: For metastatic lung adenocarcinoma patients with low PD-L1 expression, IBC is the preferred first-line therapy in terms of survival. However, the AEs should be carefully concerned.

Abstract B008: High expression of the exhaustion markers PD1 and PD-L1 in non-muscle invasive bladder cancer is associated with poor outcome following Bacillus Calmette-Guérin immunotherapy

Abstract Introduction: The recommended treatment for high-risk non-muscle invasive bladder cancer (NMIBC) is intravesical instillations of Bacillus Calmette-Guérin (BCG). However, 40 % experience recurrence within 5 years despite completing BCG treatment. T cell exhaustion has been associated with poor outcome following treatment with BCG. Here we investigated if T cell exhaustion, characterized by protein expression of PD1 and PD-L1 measured in paired samples obtained before and after BCG treatment could further explain BCG response and help predict outcome in patients with NMIBC. Methods: We included 111 patients with NMIBC, from which we had 183 TURB-T samples obtained before and after BCG treatment. Using immunohistochemistry (IHC) staining of sections from tissue microarrays (TMAs) with triplicate core biopsies, we investigated the protein expression of the exhaustion markers PD1 (clone EP239) and PD-L1 (clone 22c3). Data was analyzed using digital pathology software (Visiopharm®), where tissue areas were defined as either carcinoma or stroma based on PanCK staining. Cells were scored as positive when detection of a nucleus was combined with a positive PD1 or PD-L1 stain, which was based on visually defined thresholds to differentiate between positive and unspecific staining. In total, 167 samples from 105 patients were considered suitable for further analysis (cell count &amp;gt; 200 in carcinoma and stromal areas) with 2-3 cores per sample, resulting in a total of 441 tissue cores. The average cell count was 5732 per core (defined by positive nuclei stain). Stratification of samples into high or low expression was based on a median split of the positive cell fraction. Results: When investigating the number of PD1 and PD-L1 positive cells in the tumors (carcinoma and stroma combined), we observed that PD-1 expression significantly increased with tumor stage in pre- (p=0.002) and post-BCG (p=0.006) tumor samples. PD1 expression was also increased in high-grade tumors compared to low-grade tumors in pre-BCG samples (p = 0.001). Furthermore, we observed a significant association between tumors of higher stage and high PD-L1 expression in the pre-BCG samples (p = 0.007). Patients with low expression of PD1 and PD-L1 in the pre-BCG tumor samples had a superior high-grade recurrence-free survival (HG-RFS) compared to patients with high PD1 (p=0.002) and PD-L1 (p=0.021) expression. In addition, low expression of PD-L1 in pre-BCG tumors was correlated with a better progression-free survival compared to the patients with high PD-L1 expression (p = 0.013). Conclusion: Protein expression of PD1 and PD-L1 in pre-BCG tumor samples were correlated to higher stage and grade as well as worse HGFRS, indicating that T cell exhaustion plays an important role in resistance to BCG treatment. Citation Format: Tine G. Andreasen, Trine Strandgaard, Jørgen B. Jensen, Lars Dyrskjøt. High expression of the exhaustion markers PD1 and PD-L1 in non-muscle invasive bladder cancer is associated with poor outcome following Bacillus Calmette-Guérin immunotherapy [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B008.

Abstract PO2-15-10: Identifying new immune-related biomarkers in TNBC with a look at PD-L1 cell-autonomous role

Abstract Background The programmed death ligand 1 (PD-L1) has recently emerged as a target immunotherapy in Triple-negative breast cancer (TNBC). However, the tumor-intrinsic role of PD-L1 and its pathway still needs to be fully clarified. Recently, a close association between CD73, PD-L1, cancer cell steaminess and epithelial-to-mesenchymal transition phenotypes is emerging. In addition, we have previously demonstrated that miR-320a and miR-145 target PD-L1, whereas miR-30 family is known to target CD73. In this study, we aimed at investigating the role of these miRNAs as prognostic and predictive dynamic biomarkers for immunotherapy in TNBC. Additionally, we investigated whether PD-L1 exerts cellular autonomic functions in TNBC beyond its role in the immune checkpoint. Results CD73 and PD-L1 expression was assessed in a panel of breast cancer lines and the non-malignant breast cells MCF-10. We showed a significantly higher CD73 and PD-L1 expression in MDA-MB-231 (TNBC, Basal B) than in MCF-10. Conversely, in MCF-7 cells (HR +, Luminal A), CD73 and PD-L1 expression is lower than in MCF-10. Furthermore, we showed that low PDL1 expression is correlated with high levels of miR-320a and miR-145, and CD73 expression is inversely related to miR-30 expression. These putative biomarkers were also validated in two patients with different PD-L1 status. From the analysis of the data obtained by real-time qRT-PCR, we found high plasma level of CD73 and low plasma level of miR-320a, miR-145 and miR-30 in the patient with PD-L1 positive BC. On contrary, in the patient with PD-L1-negative BC, we found low plasma level of CD73 and high plasma level of miR-320a, miR-145 and miR-30. Furthermore, to explore whether PD-L1 could also have an intrinsic role in tumor development and invasiveness, we used stably MDA–MB-231 PD-L1-silenced cells. We found that cell growth, colony formation, migration rate and the ability to form spheres are consistently reduced upon shRNA-mediated PDL1 silencing. In particular, we observed a reduction in the number, diameter and volume of the 3D spheres compared to the control cells. To further demonstrate the role of PD-L1, we treated the PDL1-high expression cells MDA-MB-231, PD-L1 silenced MDA-MB-231 clones, and PD-L1 low expression cells MCF-7 with Durvalumab, an anti-PD-L1. Interestingly, we observed that in PD-L1 silenced clones and MCF-7 cells, the sphere-forming ability was increased in presence of Durvalumab treatment. On the contrary, in MDA-MB-231, Durvalumab inhibited the sphere-forming ability. Conclusion Our data confirm that PD-L1 and CD73 are targets of miR-320a/miR-145 and miR-30 respectively. These could be potential predictive dynamic biomarkers for chemotherapy, ICIs and anti-CD73 therapeutic approach. Future validations of these biomarkers in an extensive series of TNBC patients are needed to support their use in clinical practice. Here, we further characterized the cellular autonomic role of PD-L1 in breast cancer and showed a differential role of basal PD-L1 expression in PD-L1 checkpoint inhibitors treatment efficacy. This suggests a potential role in monitoring PD-L1 expression indirect biomarkers (i.e. miR-320a, miR-145 and CD73) during ICIs treatment.

Abstract PO4-03-13: High B7-H3 expression with low PD-L1 expression identifies armored-cold tumors suggesting potential anti-B7-H3 therapy in triple-negative breast cancer

Abstract Background: Triple-negative breast cancer (TNBC) is generally regarded as the most aggressive subtype among breast cancer. B7 homolog 3 protein (B7-H3), also known as CD276, is an emerging immune checkpoint molecule, which plays a dual role in the immune system. Multiple anti-B7-H3 therapies has been raised, such as DS-7300, MGA271, MGD009, and B7-H3 chimeric antigen receptor T-cell immunotherapy (CAR-T). However, the expression of B7-H3 in TNBC and its value as a biomarker identifying therapeutic options has not been elucidated Methods: A total of 165 samples (83 non-TNBC and 82 TNBC) were included in this study, and 6 samples included paired para-tumor samples. In addition, 30 TNBC patients receiving standardized neoadjuvant chemotherapy (NAT) were recruited. After 8 cycles of NAT, the response to NAT was assessed by RECIST1.1 criterion before surgical operation. Moreover, multiple public cohorts of breast cancer and TNBC were obtained, including the TCGA dataset, the METABRIC dataset, the GSE176307 (durvalumab-based therapy) dataset, the PRJNA558949 (durvalumab-based therapy) dataset, the GSE194040 (paclitaxel-based therapy) dataset, and the GSE34138 (anthracycline-based therapy) dataset. Based on multiple in-house and public cohorts, we investigated the expression features of B7-H3 in breast cancer and checked the anti-tumor effect of the B7-H3 monoclonal antibody in mouse model. We also developed a novel classifier combined B7-H3 and PD-L1 expression in TNBC. Results: B7-H3 was highly expressed in tumor tissues in the in-house and the TCGA cohorts. B7-H3 expression did not differ significantly between non-TNBC and TNBC samples in the in-house and the TCGA cohorts, excepting for the METABIRC cohort. There was no notable difference in CD8+ cells infiltration between B7-H3 low and high expressed non-TNBC samples, but CD8+ cells was notably higher in the B7-H3 low expressed TNBC samples. The similar findings were also observed in the TCGA and the METABIRC cohorts. In addition, enrichment analysis of transcriptome data and analysis of in-house samples showed that B7-H3 was positively related to most collagens. Moreover, anti-B7-H3 therapy significantly inhibited tumor growth in mouse TNBC model, notably increased immune cells infiltration, and also reduced collagen deposition within the tumor. Given the notable value of PD-L1 in predicting immunotherapy responses, we also combined B7-H3 and PD-L1 expression to establish a novel subtyping strategy. TNBC patients with B7-H3highPDL1low feature exhibited the lowest anti-tumor immune infiltration and higher collagen deposition level. In the durvalumab-dependent cohort, paclitaxel-dependent cohort, anthracycline-dependent cohort, and our recruited NAT cohort, the B7-H3highPDL1low subgroup exhibited the lowest therapeutic response. Conclusions: Overall, this research provides a novel subtyping strategy based on the combination of B7-H3/PD-L1 expression that could potentially be applied to predict the therapeutic responses in TNBC, and suggests a potential biomarker-guided anti-B7-H3 therapy. Based on the classifier, we can select potential beneficiaries to deliver personalized medical services. Citation Format: Jie Mei, Yun Cai, Ziyi Fu, Yongmei Yin. High B7-H3 expression with low PD-L1 expression identifies armored-cold tumors suggesting potential anti-B7-H3 therapy in triple-negative breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-03-13.

Brief Report on Global Clinician Practices in the First-Line Management of Metastatic Non-Small Cell Lung Cancer

IntroductionIn the dynamic landscape of metastatic NSCLC (mNSCLC) management, marked by several frontline options and the integration of next generation sequencing (NGS) for informed decision-making, barriers persist despite advancements. This includes challenges in clinical trial recruitment. To gain global insights into clinicians’ practices, we conducted a survey on their testing and management approaches for patients with mNSCLC. MethodsThe survey, conducted from July 12 to August 20, 2023, utilized multiple-choice questions and qualitative research questions, employing the Likert Scale for comprehensive insights. ResultsA total of 127 individuals responded, with 72% affiliated with academic health systems, and 55% practicing in the USA. Regarding testing practices, 93% consistently ordered NGS for non-squamous histology, while 54% did so for squamous cell histology. Concurrent tissue and liquid biopsies were routinely ordered by 28%, while 39% reported ordering both testing platforms concurrently for select cases only. Respondents cited logistical barriers, such as insufficient tissue and lack of infrastructure, as the most common hindrance to molecular testing (76%), followed by reimbursement challenges (56%) and concerns about delayed turnaround time (50%). While most respondents were confident in interpreting NGS results, 22% lacked confidence. Concerning treatment decisions, 72% preferred awaiting molecular testing results before initiating systemic therapy. Less than 50% routinely referred patients for clinical trials in the frontline setting for mNSCLC. For patients with disease expressing high PD-L1 levels, most oncologists preferred pembrolizumab monotherapy. For disease with low PD-L1 expression, a platinum doublet chemotherapy regimen combined with pembrolizumab was favored. In disease cases with negative PD-L1 expression, a platinum doublet chemotherapy regimen with pembrolizumab was preferred. Key factors influencing oncologists' preferred immune checkpoint inhibitor (ICI) included experience with one ICI over another, preferred status per national guidelines, availability of trial data with a significant follow-up period, and consideration of drug cost. ConclusionAlthough this study demonstrates an improved awareness and adoption of ordering NGS for the management of mNSCLC, it underscores the persistence of various barriers that must be addressed to improve upon the quality of care for patients diagnosed with mNSCLC.

Effect of the STK11 mutation on therapeutic efficacy and prognosis in patients with non-small cell lung cancer: a comprehensive study based on meta-analyses and bioinformatics analyses

BackgroundThis study aimed to systematically analyze the effect of a serine/threonine kinase (STK11) mutation (STK11mut) on therapeutic efficacy and prognosis in patients with non-small cell lung cancer (NSCLC).MethodsCandidate articles were identified through a search of relevant literature published on or before April 1, 2023, in PubMed, Embase, Cochrane Library, CNKI and Wanfang databases. The extracted and analyzed data included the hazard ratios (HRs) of PFS and OS, the objective response rate (ORR) of immune checkpoint inhibitors (ICIs), and the positive rates of PD-L1 expression. The HR of PFS and OS and the merged ratios were calculated using a meta-analysis. The correlation between STK11mut and clinical characteristics was further analyzed in NSCLC datasets from public databases.ResultsFourteen retrospective studies including 4317 patients with NSCLC of whom 605 had STK11mut were included. The meta-analysis revealed that the ORR of ICIs in patients with STK11mut was 10.1% (95%CI 0.9–25.2), and the positive rate of PD-L1 expression was 41.1% (95%CI 25.3–57.0). STK11mut was associated with poor PFS (HR = 1.49, 95%CI 1.28–1.74) and poor OS (HR = 1.44, 95%CI 1.24–1.67). In the bioinformatics analysis, PFS and OS in patients with STK11 alterations were worse than those in patients without alterations (p < 0.001, p = 0.002). Nutlin-3a, 5-fluorouracil, and vinorelbine may have better sensitivity in patients with STK11mut than in those with STK11wt.ConclusionsPatients with STK11-mutant NSCLC had low PD-L1 expression and ORR to ICIs, and their PFS and OS were worse than patients with STK11wt after comprehensive treatment. In the future, more reasonable systematic treatments should be explored for this subgroup of patients with STK11-mutant NSCLC.