Programmed Death-ligand 1 Expression Research Articles

Correlation of programmed death-ligand 1 expression in tumour cells between diagnostic small biopsies performed by radial EBUS and surgical specimens of peripheral lung cancer

Background and objectiveExpression of programmed death-ligand 1 (PD-L1) in tumour cells (TCs) is predictive of immunotherapy efficacy in non-small cell lung cancer (NSCLC). Small biopsy samples collected by bronchoscopy are...

Association between programmed cell death ligand-1 expression in patients with cervical cancer and apparent diffusion coefficient values: a promising tool for patient´s immunotherapy selection.

To investigate the associations between apparent diffusion coefficient (ADC) values extracted from three different region of interest (ROI) position approaches and programmed cell death ligand-1 (PD-L1) expression, and evaluate the performance of the nomogram established based on ADC values and clinicopathological parameters in predicting PD-L1 expression in cervical cancer (CC) patients. Through retrospective recruitment, a training cohort of 683 CC patients was created, and a validation cohort of 332 CC patients was prospectively recruited. ROIs were delineated using three different methods to measure the mean ADC (ADCmean), single-section ADC (ADCss), and the minimum ADC of tumors (ADCmin). Logistic regression was employed to identify independent factors related to PD-L1 expression. A nomogram was drawn based on ADC values combined with clinicopathological features, its discrimination and calibration performances were estimated using the area under the curve (AUC) of receiver operating characteristic and calibration curve. The clinical benefits were evaluated by decision curve analysis. The ADCmin independently correlated with PD-L1 expression. The nomogram constructed with ADCmin and other independent clinicopathological-related factors: FIGO staging, pathological grade, parametrial invasion, and lymph node status demonstrated excellent diagnostic performance (AUC = 0.912 and 0.903, respectively), good calibration capacities, and greater net benefits compared to the clinicopathological model in both the training and validation cohorts. ADCmin independently correlated PD-L1 expression, and the nomogram established with ADCmin and clinicopathological independent prognostic factors had a strong predictive performance for PD-L1 expression, thereby serving as a promising tool for selecting cases eligible for immunotherapy. The minimum ADC can serve as a reliable imaging biomarker related to PD-L1 expression; the established nomogram combines the minimum ADC and clinicopathological factors that can assist clinical immunotherapy decisions.

Cancer cell-specific PD-L1 expression is a predictor of poor outcome in patients with locally advanced oral cavity squamous cell carcinoma

BackgroundLocally advanced oral cavity squamous cell carcinoma (OCSCC) presents a significant clinical challenge despite being partially responsive to standard treatment modalities. This study investigates the prognostic implications of programmed death-ligand...

Brief Report: Not Created Equal: Survival Differences by KRAS Mutation Subtype in NSCLC Treated With Immunotherapy

IntroductionThe predictive and prognostic implications of different KRAS mutation (KRASm) subtypes in metastatic NSCLC have not been clearly defined. We used a nationwide observational database to investigate whether KRASm subtypes differ in their association with survival in metastatic NSCLC treated with immune checkpoint inhibitor (ICI)-based therapy, across programmed death-ligand 1 (PD-L1) levels. MethodsPatients with advanced nonsquamous NSCLC who initiated first-line ICI-based therapy from 2016 to 2021 and had known PD-L1 expression and comprehensive genomic profiling including KRAS, STK11, KEAP1, and TP53 were included. Within PD-L1 expression subgroups (<1%, 1%–49%, ≥50%), Cox multivariable regression was used to evaluate the association between KRASm subtypes (G12C, G12V, G12D, other KRASm) and overall survival, estimated using Kaplan-Meier methodology. ResultsAmong the 1539 patients, 819 patients were KRAS wild type (KRASwt) and 720 were KRASm (296 KRAS G12C, 143 KRAS G12V, 97 KRAS G12D, 184 other KRASm). In the 50% or higher PD-L1 subgroup, patients with KRAS G12V had worse survival (median overall survival [mOS] = 8.2 mo) compared with KRASwt (mOS = 13.3 mo) and other KRAS subgroups (mOS ranging from 13.4 to 19.9 mo). On adjusted Cox multivariable regression in the 50% or higher PD-L1 subgroup, the hazard ratio for death for KRAS G12V ranged from 1.53 to 1.78 compared with KRASwt and other KRASm subtypes (all p < 0.05). ConclusionsAlthough patients with 50% or higher PD-L1 with KRAS G12C, G12D, and other subtypes exhibited similar survival to KRASwt, KRAS G12V was associated with significantly worse survival than KRASwt and other KRASm subtypes. All KRASm should not be regarded as uniform predictors of ICI responsiveness, even with high PD-L1 expression; KRAS G12V tumors may have worse outcomes with ICI-based therapy and benefit from treatment intensification.

The relationship between sarcopenia and metabolic parameters of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and the prognostic value of sarcopenia in early-stage non-small cell lung cancer.

Patients with lung cancer face a heightened risk of developing sarcopenia. Despite this known risk, the impact of sarcopenia on the long-term prognosis of lung cancer patients, specifically concerning progression-free survival (PFS) and overall survival (OS), remains unclear. The primary objective of our study was to examine the correlation between metabolic parameters derived from 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) and sarcopenia, as well as the prognostic value of sarcopenia in patients with surgically resected early-stage non-small cell lung cancer (NSCLC). In this retrospective cross-sectional study, we analyzed 187 NSCLC patients who underwent 18F-FDG PET/CT at the First Affiliated Hospital of Soochow University between March 2019 and October 2023. Patients were divided into two groups based on the presence (n=46) or absence (n=141) of sarcopenia. The correlation between sarcopenia, metabolic parameters, and patient characteristics was evaluated using chi-square and Mann-Whitney U tests. Survival analyses, including PFS and OS, were conducted using Kaplan-Meier analysis and Cox proportional hazards regression. Based on sarcopenia, metabolic parameters and patient characteristics, patients were classified into high-risk (n=28), intermediate-risk (n=121), and low-risk (n=38) groups. Our analysis identified gender, body mass index (BMI), psoas Hounsfield unit (HU), and maximum standardized uptake value of the psoas major muscle (SUVmax-Muscle) as independent predictors of sarcopenia (P<0.05 for all). A nomogram model, utilizing these parameters, was constructed to predict sarcopenia. Survival analysis further demonstrated that total lesion glycolysis [hazard ratio (HR) =2.499; 95% confidence interval (CI): 2.014-3.267; P=0.016], sarcopenia (HR =3.323; 95% CI: 1.748-6.316; P<0.001), and programmed death ligand-1 (PD-L1) expression (HR =0.093; 95% CI: 0.012-0.698; P=0.021) emerged as independent predictors of OS in early-stage NSCLC. Notably, patients categorized as high-risk, characterized by elevated total lesion glycolysis, presence of sarcopenia, and PD-L1 positivity, exhibited a significantly poorer prognosis compared to the intermediate-risk (P<0.05) and low-risk groups (P<0.05). Our findings indicated an inverse relationship between SUVmax-Muscle or psoas HU with the incidence of sarcopenia in NSCLC patients. Additionally, total lesion glycolysis, sarcopenia, and PD-L1 expression were identified as independent prognostic factors for OS in early-stage NSCLC. The risk stratification model, incorporating total lesion glycolysis, sarcopenia, and PD-L1 expression, assumed a pivotal role in guiding personalized therapy decisions and post-treatment monitoring.

Clinical Outcomes of Maintenance Durvalumab After Definitive Concurrent Chemoradiotherapy in Unresectable Locally Advanced Stage III NSCLC According to EGFR and ALK Status: Korean Cancer Study Group LU-22-18

IntroductionThe role of maintenance durvalumab after definitive concurrent chemoradiotherapy (CCRT) in unresectable locally advanced NSCLC with EGFR mutation or ALK translocation remains unclear. We compared the effectiveness of durvalumab maintenance therapy in groups with EGFR/ALK wild-type versus those with EGFR or ALK mutations. MethodsIn this retrospective multicenter observational study, patients with locally advanced NSCLC without progression after CCRT followed by maintenance durvalumab and available molecular test results (EGFR and ALK) were eligible. The primary objective was to compare progression-free survival (PFS) between EGFR/ALK wild-type and EGFR or ALK mutant NSCLC. Secondary objectives include overall survival according to EGFR or ALK mutation and programmed death-ligand 1 (PD-L1) expression. ResultsAmong 339 patients, 279 had wild-type EGFR/ALK, 41 had EGFR mutations and 19 had ALK translocations. The median age was 68 years with 276 male individuals (81.4%) and 63 female individuals (18.6%), 165 (49.3%) had adenocarcinoma, 149 (44.5%) had squamous cell carcinoma, and 21 (6.3%) had other histologic types, 120 (35.4%) had stage IIIA, 168 (49.6%) stage IIIB, and 51 (15.0%) had stage IIIC. Most of the patients (n = 288, 85%) achieved partial response to CCRT, two (0.6%) had a complete response, and 49 patients (14.4%) had stable disease. Excluding four patients with unknown PD-L1 tumor proportion score (TPS), 16 (4.8%) had a PD-L1 TPS of 0, 168 (50.1%) had 1 to 49, and 151 (45.1%) had 50 or higher. The median PFS was 21.4 months (95% confidence interval [CI]: 17.3–25.3) for the EGFR/ALK wild-type group and 21.0 months (95% CI: 15.7–not available [NA]) for the EGFR or ALK mutant group with no significant difference (p = 0.74). Significant differences occurred in PFS on the basis of PD-L1 expression with values of 13.6 (95% CI: 10.5–NA), 18.7 (95% CI: 15.1–26.9), and 24.7 (95% CI: 20.7–NA) months for TPS of 0, 1–49, and 50 or higher, respectively (p = 0.02). ConclusionsDurvalumab maintenance therapy after definitive CCRT in unresectable locally advanced NSCLC patients with EGFR or ALK mutation demonstrates comparable clinical outcomes to those with wild-type EGFR/ALK when PD-L1 expression is present.

Cabozantinib enhances CAIX specific CAR-T cells against renal cancer by improving effector functions and augmenting tumor immune microenvironment

Despite demonstrating promising outcomes in treating hematologic malignancies, the efficacy of chimeric antigen receptor-modified T (CAR-T) cell therapy remains limited when applied to solid tumors due to tumor immune microenvironment (TIME). Strategies to augment CAR-T cell efficacy against solid tumors have been investigated by ameliorating TIME to a certain extent. In this study, Cabozantinib was utilized in combination with CAR-T cells targeting carbonic anhydrase IX (CAIX) for the treatment of renal cancer. Our findings indicate that combination therapy with CAIX-CAR-T and Cabozantinib demonstrated synergistic efficacy against an orthotopic xenograft tumor model and a subcutaneous tumor model of renal cell carcinoma in mice. Mechanistically, it was observed that CAR-T cells combined with Cabozantinib led to an increase in the infiltration of tumor-infiltrating T cells, while reducing tumor-associated macrophages and M2 polarization. Additionally, Cabozantinib blocked the programmed cell death-1 (PD-1)/programmed death-ligand 1 (PD-L1) axis by decreasing the expression of PD-L1 in tumor cells and PD-1 in T cells. Furthermore, Cabozantinib promoted CAR-T cell effector function and reduced T cell exhaustion. This combination therapy represents a novel approach to enhancing CAR-T cell efficacy against solid tumors and holds significant promise for advancing CAR-T cell therapy in clinical settings.

Bempegaldesleukin plus nivolumab in first-line advanced/metastatic urothelial carcinoma: Results from a phase II single-arm study (PIVOT-10)

BackgroundIn PIVOT-02, bempegaldesleukin (BEMPEG), a pegylated interleukin-2 cytokine prodrug, in combination with nivolumab (NIVO), a Programmed cell death protein 1 inhibitor, demonstrated the potential to provide additional benefits over immune checkpoint inhibitor monotherapy in patients with urothelial carcinoma, warranting further investigation. We evaluated BEMPEG plus NIVO in cisplatin-ineligible patients with previously untreated locally advanced or metastatic urothelial carcinoma. MethodsThis open-label, multicenter, single-arm, phase II study enrolled patients with locally advanced/surgically unresectable or metastatic urothelial carcinoma and who were ineligible for cisplatin-based treatment. Patients received BEMPEG plus NIVO were administered intravenously every 3 weeks for ≤2 years or until progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by blinded independent central review (BICR) in patients with low programmed death ligand-1 (PD-L1) expression. Secondary endpoints included ORR and duration of response in the overall population. Progression-free survival (PFS) and overall survival (OS) were exploratory endpoints. ResultsOne hundred and eighty-eight patients were enrolled; 123 patients were PD-L1 low (combined positive score [CPS] <10; 65.4%), 59 were PD-L1 high (31.4%; CPS ≥10), and 6 had PD-L1 status unknown (3.2%). ORR per blinded independent central review in patients with PD-L1-low tumors was 17.9% (95% confidence interval [CI] 11.6–25.8) while in all treated patients was 19.7% (95% CI 14.3–26.1). Median PFS and OS in the overall population were 3.0 months and 12.6 months, respectively. BEMPEG plus NIVO combination was well tolerated, with a safety profile similar to previously reported trials; no new or unexpected safety signals were reported. ConclusionsBEMPEG plus NIVO did not meet the efficacy threshold for ORR in patients with previously untreated locally advanced or metastatic urothelial carcinoma and low PD-L1 expression.

PD-L1 as a Biomarker for the Efficacy of Durvalumab in Stage III EGFR Mutant NSCLC.

Durvalumab consolidation is less effective in patients with epidermal growth factor receptor mutant (EGFR M+) NSCLC. Studies of durvalumab on EGFR M+ NSCLC as an expression of programmed death-ligand 1 (PD-L1) expression are limited. The purpose of this study was to determine the effect of durvalumab on PD-L1 expression in EGFR M+ patients. This study included 249 unresectable stage III NSCLC patients treated with durvalumab. The primary outcome was progression-free survival (PFS). Cox multivariate analysis was performed based on EGFR and PD-L1 statuses: EGFR M-, PD-L1 ≥50% (cohort A); EGFR M-, PD-L1 <50% (cohort B); EGFR M+, PD-L1 ≥50% (cohort C); and EGFR M+, PD-L1 <50% (cohort D). Overall, 31 of 249 (12.4%) and 218 of the 249 (87.6%) patients had EGFR M+ and EGFR M- NSCLC, respectively. Median PFSs and OSs did not differ (PFS: 16.6 vs. 18.7 months, p=0.591; OS: 37.4 vs. 35.7 months, p=0.271). Median PFS of cohort A did not significantly differ from the median PFSs of cohorts B and C, but it was significantly longer than the median PFS of cohort D (23.7 vs. 15.2 months, p=0.045). Cox multivariate analysis revealed that cohort D exhibited a worse PFS (adjusted hazard ratio=2.27, 95% confidence interval=1.11-4.66, p=0.025) compared with cohort A. Median OSs were not different between the four cohorts. Durvalumab consolidation provided similar benefit in EGFR M+ patients with PD-L1 ≥50% compared with EGFR M- patients. A therapeutic role of durvalumab in patients with EGFR M+, high PD-L1 unresectable stage III NSCLC should be considered.

MiR-140-3p Improves Sensitivity to Docetaxel by Suppressing PD-L1/ABCG2/MVP Expression in Lung Adenocarcinoma.

Lung adenocarcinoma (LUAD) or lung squamous cell carcinoma (LUSC) accounts for the majority of non-small cell lung cancer (NSCLC), and overexpression of programmed death ligand 1 (PD-L1) in these cells is known to induce tumor immune evasion or drug resistance. However, detailed studies are needed to determine whether microRNAs (miRNAs) that reduce PD-L1 expression can suppress drug resistance in NSCLC. Kaplan Meier plotter and Receiver Operating Characteristic plotter were used to determine the effect of specific miRNAs on survival and chemotherapy response in NSCLC patients. Cell viability, colony formation and invasion assays, and qPCR analyses were also performed. The expression of miRNA-140-3p (miR-140-3p) was lower in LUAD patients, compared to the normal group, and low expression of miR-140-3p was associated with poor survival of LUAD patients, but not in LUSC. The miR-140-3p mimic inhibited proliferation, colony formation, and invasion of LUAD cells. Interestingly, the expression of miR-140-3p was significantly lower in the group of LUAD patients who did not respond to docetaxel. In LUAD cells, combined treatment with miR-140-3p and docetaxel significantly reduced cell viability as well as the expression of ABCG2 and MVP, genes associated with drug resistance, compared to either treatment alone. Additionally, combined injection of miR-140-3p mimic and docetaxel significantly inhibited tumor growth compared to treatment with docetaxel alone. These results suggest that the high expression of miR-140-3p in LUAD is correlated with good patient prognosis and may contribute to the treatment of LUAD, especially by increasing responsiveness to docetaxel.

Transforming Lung Cancer Management: A Promising Case Study of Immune Checkpoint Inhibitor Success Following a Multidisciplinary Approach

A 54-year-old female patient diagnosed with Stage IIIb squamous cell carcinoma (cT2aN3M0) initially received chemoradiotherapy. Two years after initial treatment, cancer relapse led to the administration of nivolumab, which was halted due to the development of drug-induced pneumonitis. Subsequent management with prednisolone and eight different cytotoxic agents failed to prevent metastasis to the cervical lymph nodes. The tumor’s programmed death-ligand 1 (PD-L1) expression rate was recorded at 10%. Four years after her diagnosis, the patient received a ninth-line therapy combining cisplatin, gemcitabine, and necitumumab, followed by palliative neck radiation due to increasing lymph node size. Remarkable tumor regression occurred three months after introducing atezolizumab as the tenth-line treatment, suggesting that previous treatments, particularly radiotherapy and cisplatin, might have enhanced PD-L1 expression, aligning with the existing literature. This case highlights the urgent need for further research to elucidate the intricate interplay between treatment history and PD-L1 expression in squamous cell carcinoma, emphasizing the importance of accumulating case studies to inform therapeutic strategies.

Expression of Programmed Death Ligand 1 and Indoleamine 2,3-Dioxygenase in Oral Lichen Planus and Oral Lichenoid Lesions.

Oral lichen planus (OLP) and oral lichenoid lesions (OLL) are inflammatory T-cell mediated disorders of the oral mucosa (OM). Both are associated with an increased risk of oral squamous cell carcinoma, with OLL possibly having a higher rate of malignant transformation than OLP. Programmed death ligand 1 (PD-L1) and indoleamine 2,3-dioxygenase (IDO) are immunosuppressive molecules possessing inhibitory effect on T-cells and have been implicated in carcinogenesis. The aim of this study was to examine the expression of PD-L1 and IDO in OLP and OLL. Sixty-eight formalin-fixed, paraffin-embedded tissue samples diagnosed as OLP, compatible with OLP, or OLL were divided into OLP (n = 39) or OLL (n = 29) groups based on both clinical and histopathological diagnostic criteria. Samples of healthy OM (n = 9) served as controls. Samples were immunohistochemically stained for PD-L1 and IDO, and staining distribution and intensity were evaluated. Immunohistochemical expression of PD-L1 was increased in the basal and intermediate layers of epithelium in OLP and in lamina propria in both OLP and OLL compared to controls. OLP and OLL showed increased expression of IDO in epithelium and lamina propria compared to controls. PD-L1 staining intensity in the basal epithelial layer, and IDO staining intensity in lamina propria were increased in OLP compared to OLL. The results indicate that the expression of PD-L1 and IDO increases in OLP and OLL, suggesting that these molecules may play a role in the pathogenesis of both disorders.

Gamabufotalin loaded micro-nanocomposites for multimodal therapy of metastatic TNBC by efficiently inducing ICD

Gamabufotalin (CS-6), a main active compound derived from Chinese medicine Chansu, exhibits a robust inhibitory effect on programmed death-ligand 1 (PD-L1) in triple-negative breast cancer (TNBC) cells. Despite its potential for tumor therapy, the medical application of CS-6 is constrained by its hydrophobic nature, lack of targeting capability, and weak immunogenic cell death (ICD) effect. To address these limitations and improve the therapeutic efficiency of this drug against metastatic TNBC, we designed a new kind of CS-6@CPB-S.lux that integrates carboxy-Prussian blue nanoparticles (CPB NPs), CS-6, and attenuated Salmonella typhimurium (S.lux) for TNBC therapy. In vitro and in vivo results have confirmed that CS-6@CPB NPs were efficiently delivered to neoplastic tissue by the tumor hypoxic chemotaxis property of S.lux, wherein the nanomedicine induced significant tumor cell necroptosis and apoptosis via photothermal therapy (PTT) of CPB NPs and chemotherapy of CS-6, which elicited ICD and inhibited PD-L1 expression, resulting in dendritic cells (DCs) maturation and effector T cells activation to comprehensively eliminate tumors. Additionally, the CS-6@CPB-S.lux + Laser treatment significantly transformed the immunosuppressive tumor microenvironment (TME), enhancing antitumor immunity through promoting the polarization of tumor-associated macrophages into antitumorigenic M1 and reducing Tregs recruitment. Consequently, this comprehensive therapy not only inhibited primary and abscopal tumor progression but also prevented TNBC metastasis, which significantly prolonged survival time in animal models. In summary, these findings indicated an alternative approach for metastatic TNBC therapy.

Abstract C149: Relationship between PD-L1 expression and clinicopathological characteristics in Hispanic/ Latino women with breast cancer

Abstract Background: Programmed death ligand 1 (PD-L1) expression in breast cancer serves as a prognostic marker, particularly in aggressive subtypes like triple-negative breast cancer (TNBC), where it helps in predicting response to immune checkpoint inhibitors and guides immunotherapy use. Although several studies have assessed the prevalence of PD-L1 expression in breast cancer, data from the Hispanic population, especially in Latin American countries, is lacking. This study evaluates PD-L1 expression and its correlation with pathological features in Colombian women. Methods: Women with breast cancer tested for PD-L1 were selected from the archives of the Oncologic Pathology Department at the National Cancer Institute of Colombia from September 2021 to May 2024. Information from their pathology reports was extracted, and correlation analyses were carried out using Fisher's exact test Results: A total of 60 reports were screened, comprising 56 cases of ductal invasive breast carcinoma and 1 case of lobular invasive breast carcinoma. 48 individuals were tested using the PD-L1 22C3 antibody, with 41.67% of them being positive for PD-L1 expression. Among the 48 tumors tested with 22C3, 35 cases were classified as TNBC, and 13 cases corresponded to luminal B subtype with a low positive expression (1-10%) of estrogen receptors. The percentage of positive PD-L1 cases was 37.14% for TNBC and 53.85% for the luminal B subtype. Furthermore, 5 HER2-low cases were identified with 2 of them being positive for PD-L1 expression. In the correlation analyses, PD-L1 positive expression was significantly associated with a more aggressive histologic grade compared to PD-L1 negative tumors (p = 0.007). No significant association was found between PD-L1 expression and HR, HER2, or KI67 status, nor with age, necrosis, lymphovascular involvement, perineural invasion, desmoplastic response, or immune cell infiltration. Among the 12 individuals tested for PD-L1 with the SP142 antibody, none showed positive expression, precluding correlation analyses. Conclusion: This study highlights a significant association between PD-L1 expression and aggressive histologic grade in Colombian women with breast cancer. The findings underscore the potential of PD-L1 as a prognostic marker and its relevance in guiding immunotherapy in this population. Further research is needed to explore PD-L1 expression in broader Hispanic groups to better understand its clinical implications. Citation Format: Daniel Mendivelso-González, Patricia López- Correa, Nicolás Prada-Aceros, Alfredo E Romero-Rojas, Rafael Parra-Medina. Relationship between PD-L1 expression and clinicopathological characteristics in Hispanic/ Latino women with breast cancer [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C149.

Abstract C067: Immune thrombocytopenia induced by PD-1/PD-L1 inhibitors in a patient with non-small cell lung adenocarcinoma: A case report and literature review

Abstract Introduction: The introduction of immunotherapy, particularly programmed cell death protein 1 (PD-1) and programmed cell death-ligand 1 (PD-L1) inhibitors, has transformed the treatment paradigm for non-small cell lung adenocarcinoma (NSCLC), significantly improving patient survival rates. However, alongside their immune-activating effects, these agents can also lead to immune-related adverse events (irAEs), affecting various organ systems. Among these, immune thrombocytopenia (ITP) is a rare but potentially life-threatening complication characterized by the destruction of platelets by autoantibodies, resulting in decreased platelet counts and an increased risk of bleeding. While ITP has been identified as a complication of immunotherapy, particularly PD-1 or PD-L1 inhibitors, its incidence, clinical presentation, and management remain poorly understood. Case Presentation: The 73-year-old female with stage IIIA poorly differentiated NSCLC who received chemotherapy with Taxol/Carboplatin and concurrent radiation therapy followed by a right upper lobectomy, initiated on immunotherapy with durvalumab, a PD-L1 inhibitor, developed severe thrombocytopenia (grade 4) after receiving two cycles of durvalumab. Despite steroid treatment, her condition persisted, indicating immune-related adverse events (irAEs). After confirming the diagnosis through further investigation, including molecular analysis, the patient was treated with intravenous immunoglobulin (IVIG), which significantly increased her platelet counts. Durvalumab was discontinued, and fostamatinib, a spleen tyrosine kinase (SYK) inhibitor, was initiated to manage the irAEs effectively. Discussion: ITP is recognized as an immune-related adverse event (irAE) associated with PD-1 or PD-L1 inhibitors, although it remains rare and poorly understood. Several case reports have highlighted the occurrence of ITP induced by these inhibitors, demonstrating varied clinical presentations and responses to treatment. Mechanisms underlying ITP induction by PD-1/PD-L1 inhibitors are not fully elucidated but may involve immune dysregulation, including CD4+ and CD8+ T cell activation, production of antiplatelet antibodies, and increased expression of PD-L1 on platelets. Management strategies for ITP induced by PD-1/PD-L1 inhibitors include steroids, intravenous immunoglobulin (IVIG) therapy, recombinant human thrombopoietin (TPO), interleukin-6 (IL-6) receptor antagonists, and immunosuppressive agents. However, the effectiveness of these treatments varies among patients, highlighting the need for individualized approaches and further research to optimize management strategies. Conclusion: The prompt recognition and management of ITP induced by PD-1/PD-L1 inhibitors are essential for ensuring favorable patient outcomes. Further research is needed to understand the underlying mechanisms and develop effective prevention and management strategies for this rare but serious immune-related adverse event. Citation Format: Aliya M Khan, Richa Dawar. Immune thrombocytopenia induced by PD-1/PD-L1 inhibitors in a patient with non-small cell lung adenocarcinoma: A case report and literature review [abstract]. In: Proceedings of the 17th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2024 Sep 21-24; Los Angeles, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2024;33(9 Suppl):Abstract nr C067.

Concordance of PD-L1 Expression in Metastatic Triple-negative Breast Cancer Between the 22C3 and E1L3N Antibodies Using Combined Positive Scoring.

For patients with metastatic triple-negative breast cancer (TNBC), treatment with pembrolizumab is dependent on the accurate determination of programmed death ligand 1 (PD-L1) expression using immunohistochemistry (IHC). This study evaluated the interobserver concordance in assessing PD-L1 expression on TNBC samples using the commercial 22C3 IHC assay and an in-house assay based on the E1L3N antibody. Concordance between the 22C3 and the E1L3N IHC assays was evaluated on TNBC samples read by a commercial laboratory and a Brigham and Women's Hospital breast pathologist (BWH reader). Each slide was given a PD-L1 combined positive score (CPS) and was considered PD-L1 positive or negative based on the CPS cutoff of 10. Interobserver concordance for the assays was also evaluated on a subset of samples between 2 and 3 independent readers. On 71 samples, 2 independent readers (1 BWH reader and commercial laboratory) using E1L3N and 22C3, respectively, reached agreement on PD-L1 status (positive/negative) on 64 samples (90.1%). Using 22C3, 2 independent readers reached agreement on PD-L1 status on 30 of 36 samples (83.3%), and 3 independent readers reached agreement on 16 of 27 samples (59.3%). Using E1L3N, 2 BWH readers reached agreement on PD-L1 status on 18 of 27 samples (66.7%). Three BWH readers reached an agreement on 2 of 12 of the most challenging samples (16.7%). In conclusion, concordance between E1L3N and 22C3 testing using CPS for PD-L1 in metastatic TNBC was >90%. However, certain cases were challenging to agree upon using current threshold criteria, highlighting the need for more standardized evidence-based methods to assess PD-L1 expression.

CD38 symmetric dimethyl site R58 promotes malignant tumor cell immune escape by regulating the cAMP-GSK3β-PD-L1 axis

In recent years, immunotherapy has emerged as an effective approach for treating tumors, with programmed cell death ligand 1 (PD-L1)/programmed cell death protein-1 (PD-1) immune checkpoint blockade (ICB) being a promising strategy. However, suboptimal therapeutic efficacy limits its clinical benefit. Understanding the regulation mechanism of PD-L1 expression is crucial for improving anti-PD-L1/PD-1 therapy and developing more effective tumor immunotherapy. Previous studies have revealed that resistance to PD-L1/PD-1 blockade therapy arises from the upregulation of CD38 on tumor cells induced by ATRA and IFN-β, which mediates the inhibition of CD8+ T cell function through adenosine receptor signaling, thereby promoting immune evasion.Yet, the precise role of CD38 in regulating PD-L1 on malignant tumor cells and its impact on CD8+ T cells through PD-L1 remain unclear. Here, we demonstrate that CD38 is highly expressed in malignant tumors (lung cancer, nasopharyngeal carcinoma, cervical cancer) and upregulates PD-L1 protein expression, impairing CD8+ T cell function. Mechanistically, CD38 phosphorylates GSK3β via the adenosine-activated cAMP-PKA signaling pathway, leading to GSK3β inactivation and enhanced PD-L1 stability and expression, facilitating tumor immune escape. Furthermore, we identify PRMT5 as a novel CD38-interacting molecule that symmetrically dimethylates CD38 arginine position 58, augmenting PD-L1 stability and expression through the ADO-cAMP-GSK3β signaling axis. This inhibits CD8+ T cell-mediated tumor cell killing, enabling tumor cells to evade immune surveillance. Our findings suggest that targeting the CD38 R58 site offers a new avenue for enhancing anti-PD-L1/PD-1 therapy efficacy in tumor treatment.

Beta cell extracellular vesicle PD-L1 as a novel regulator of CD8+ T cell activity and biomarker during the evolution of Type 1 Diabetes.

Surviving beta cells in type 1 diabetes respond to inflammation by upregulating programmed death-ligand 1 (PD-L1) to engage immune cell programmed death-1 (PD-1) and limit destruction by self-reactive immune cells. Extracellular vesicles (EVs) and their cargo can serve as biomarkers of beta cell health and contribute to islet intercellular communication. We hypothesized that the inflammatory milieu of type 1 diabetes increases PD-L1 in beta cell EV cargo and that EV PD-L1 may protect beta cells against immune-mediated cell death. Beta cell lines and human islets were treated with proinflammatory cytokines to model the proinflammatory type 1 diabetes microenvironment. EVs were isolated using ultracentrifugation or size exclusion chromatography and analysed via immunoblot, flow cytometry, and ELISA. EV PD-L1: PD-1 binding was assessed using a competitive binding assay and in vitro functional assays testing the ability of EV PD-L1 to inhibit NOD CD8 T cells. Plasma EV and soluble PD-L1 were assayed in plasma of individuals with islet autoantibody positivity (Ab+) or recent-onset type 1 diabetes and compared to non-diabetic controls. PD-L1 protein colocalized with tetraspanin-associated proteins intracellularly and was detected on the surface of beta cell EVs. 24-h IFN-α or IFN-γ treatment induced a two-fold increase in EV PD-L1 cargo without a corresponding increase in number of EVs. IFN exposure predominantly increased PD-L1 expression on the surface of beta cell EVs and beta cell EV PD-L1 showed a dose-dependent capacity to bind PD-1. Functional experiments demonstrated specific effects of beta cell EV PD-L1 to suppress proliferation and cytotoxicity of murine CD8 T cells. Plasma EV PD-L1 levels were increased in islet Ab+ individuals, particularly in those with single Ab+, Additionally, in from individuals with either Ab+ or type 1 diabetes, but not in controls, plasma EV PD-L1 positively correlated with circulating C-peptide, suggesting that higher EV-PD-L1 could be protective for residual beta cell function. IFN exposure increases PD-L1 on the beta cell EV surface. Beta cell EV PD-L1 binds PD1 and inhibits CD8 T cell proliferation and cytotoxicity. Circulating EV PD-L1 is higher in islet autoantibody positive patients compared to controls. Circulating EV PD-L1 levels correlate with residual C-peptide at different stages in type 1 diabetes progression. These findings suggest that EV PD-L1 could contribute to heterogeneity in type 1 diabetes progression and residual beta cell function and raise the possibility that EV PD-L1 could be exploited as a means to inhibit immune-mediated beta cell death.

High-resolution spiral microfluidic channel integrated electrochemical device for isolation and detection of extracellular vesicles without lipoprotein contamination

Recent studies have indicated significant correlation between the concentration of immune checkpoint markers borne by extracellular vesicles (EVs) and the efficacy of immunotherapy. This study introduces a high-resolution spiral microfluidic channel-integrated electrochemical device (HiMEc), which is designed to isolate and detect EVs carrying the immune checkpoint markers programmed death ligand 1 (PD-L1) and programmed death protein 1 (PD-1), devoid of plasma-abundant lipoprotein contamination. Antigen-antibody reactions were applied to immobilize the lipoproteins on bead surfaces within the plasma, establishing a size differential with EVs. A plasma sample was then introduced into the spiral microfluidic channel, which facilitated the acquisition of nanometer-sized EVs and the elimination of micrometer-sized lipoprotein-bead complexes, along with the isolation and quantification of EVs using HiMEc. PD-L1 and PD-1 expression on EVs was evaluated in 30 plasma samples (10 from healthy donors, 20 from lung cancer patients) using HiMEc and compared to the results obtained from standard tissue-based PD-L1 testing, noting that HiMEc could be utilized to select further potential candidates. The obtained results are expected to contribute positively to the clinical assessment of potential immunotherapy beneficiaries.

The efficacy and safety of neoadjuvant immunochemotherapy in resectable stage I-III non-small cell lung cancer: a systematic review and network meta-analysis.

Neoadjuvant immunochemotherapy (NICT) is a new treatment method for resectable non-small-cell lung cancer (NSCLC). Network meta-analysis assessed efficacy, safety, and optimal treatment. We searched for randomized controlled trials (RCTs) comparing NICT with neoadjuvant chemotherapy (NCT) in PubMed, Embase, Web of Science, Cochrane Library, and international conferences. Outcomes were surgical resection rate, pathological complete response(pCR),event-free survival (EFS), and Grade 3-5 treatment-related adverse events (TRAEs). RCTs of 3,387 patients, six treatment combinations, and two modalities were included. Meta-analysis showed that NICT yielded higher pCR and EFS rates than NCT. The toripalimab-chemotherapy combination had the highest surgical resection rate (OR = 1.68, 95% CI: 1.05-2.73), pCR (OR = 38.84, 95% CI: 11.05-268.19) and EFS (HR = 0.40, 95% CI: 0.28-0.58).This regimen worked well for patients with low programmed death-ligand 1 (PD-L1) expression or squamous cell pathology. For high PD-L1 expression and patients with NSCLC, neoadjuvant nivolumab with chemotherapy had the most efficacy. The incidence of treatment-related adverse events increased with longer treatment cycles, with perioperative nivolumab combined with chemotherapy showing the worst safety profile (RR = 1.32, 95% CI: 1.00-1.76), while neoadjuvant nivolumab combined with chemotherapy alone had the best safety profile (RR = 0.91, 95% CI: 0.68-1.21). Indirect comparison showed no survival benefit for neoadjuvant-adjuvant immunotherapy (HR = 0.93, 95% CI: 0.65-1.35). In the indirect comparison between the two immune checkpoint inhibitors(ICIs), although there was no significant difference in EFS (HR = 0.81, 95% CI: 0.61-1.08), PD-1 inhibitors may still be the most effective treatment option. NICT effectively and safely treats resectable NSCLC. The optimal treatment combination is typically toripalimab and chemotherapy. Treatment based on PD-L1 expression and pathological type is recommended.