Tumor Programmed Death Ligand 1 Expression Research Articles

Contribution of tumour and immune cells to PD-L1 expression as a predictive biomarker in metastatic triple-negative breast cancer: exploratory analysis from KEYNOTE-119.

The efficacy of pembrolizumab monotherapy versus chemotherapy increased with increasing programmed death ligand 1 (PD-L1) expression, as quantified by combined positive score (CPS; PD-L1 expression on both tumour cells and immune cells) in patients with previously treated metastatic triple-negative breast cancer (mTNBC) in the phase 3 KEYNOTE-119 study. This exploratory analysis was conducted to determine whether the expression of PD-L1 on tumour cells contributes to the predictive value of PD-L1 CPS in mTNBC. PD-L1 expression in tumour samples was assessed using PD-L1 IHC 22C3 pharmDx and quantified using both CPS and tumour proportion score (TPS; PD-L1 expression on tumour cells alone). Calculated immune cell density (CID) was defined as CPS minus TPS. The ability of each scoring method (CPS, TPS, and CID) to predict clinical outcomes with pembrolizumab was evaluated. With pembrolizumab, the area under the receiver operating characteristic curve was 0.69 (95% CI = 0.58-0.80) for CPS, 0.55 (95% CI = 0.46-0.64) for TPS, and 0.67 (95% CI = 0.56-0.77) for CID. After correction for cutoff prevalence, CPS performed as well as, if not better than, CID with respect to predicting objective response rate, progression-free survival, and overall survival. Data from this exploratory analysis suggest that, although PD-L1 expression on immune cells alone is predictive of response to programmed death 1 blockade in mTNBC, adding tumour PD-L1 expression assessment (i.e. CPS, which combines immune cell and tumour cell PD-L1 expression) may improve prediction. PD-L1 CPS thus remains an effective and broadly applicable uniform scoring system for enriching response to programmed death 1 blockade with pembrolizumab in mTNBC as well as other tumour types.

Contrasting Roles of Programmed Death-Ligand 1 Expression in Tumor and Stroma in Prognosis of Esophageal Squamous Cell Carcinoma.

The assessment of programmed death-ligand 1 (PD-L1) expression in esophageal squamous cell carcinoma (ESCC) has become increasingly important with the rise of immune checkpoint inhibitors (ICIs). However, challenges persist, including subjective interpretation and the unclear significance of staining intensity, as well as contrasting roles in tumoral and stromal regions. Our study enhances the understanding of PD-L1 in ESCCs by analyzing its expression in tumors and stroma with H-scores, highlighting its distinct clinicopathological impacts. In a retrospective cohort of 194 ESCC specimens from surgical resection, we quantified PD-L1 expression in tumoral and stromal compartments using H-scores, analyzing whole slide images with digital pathology analysis software. Kaplan-Meier analysis demonstrated that higher PD-L1 expression is significantly associated with improved postoperative overall survival (OS) and recurrence-free survival (RFS) in both tumoral and stromal areas. Multivariable analysis identified high tumoral PD-L1 expression as an independent prognostic factor for prolonged OS and RFS (HR = 0.47, p = 0.007; HR = 0.54, p = 0.022, respectively). In a separate analysis, high stromal PD-L1 expression was found to correlate with less advanced pathological stages and a prolonged response to cytotoxic chemotherapy, with no similar correlation found for ICI treatment response. This study reveals PD-L1's contrasting role in the ESCC tumor immune microenvironment, impacting prognosis, tumor stage, and treatment response.

PD-L1 mRNA derived from tumor-educated platelets as a potential immunotherapy biomarker in non-small cell lung cancer.

To date, the role of programmed death ligand-1 (PD-L1) messenger RNA (mRNA) derived from tumor-educated platelets (TEPs) has not been well investigated in patients with advanced non-small cell lung cancer (NSCLC). A few reports have examined whether mRNA in TEPs can predict the clinical responses of patients with advanced NSCLC following immunotherapy. This study aimed to identify novel biomarkers to improve the clinical benefits and outcomes of NSCLC patients. Advanced NSCLC patients receiving a combination of immunotherapy and chemotherapy, or immunotherapy alone as a first- or second-line treatment at the Fudan University Shanghai Cancer Center were enrolled in this study. All the patients had wild-type epidermal growth factor receptor/anaplastic lymphoma kinase. The patients were enrolled in clinical trials for immune checkpoint inhibitors (ICIs), including nivolumab, pembrolizumab, atezolizumab, durvalumab, tremelimumab, and camrelizumab. Tumoral PD-L1 expression was tested by immunohistochemistry (PD-L1 22C3 pharmDx kit, Agilent, Santa Clara, CA, USA) in archived tissue samples, when available, to calculate the tumor proportion scores (TPSs). RNA and exosomal RNA of blood were isolated before immunotherapy using the Yunying RNA extraction kit (Yunying Medicine, Shanghai, China). The concentration and quality of the RNA was determined using a Qubit fluorometer (Life Technologies, Carlsbad, CA, USA). Finally, we analyzed the predictive value of TEP-derived PD-L1 mRNA expression and association with the level of the tumoral PD-L1 expression. In total, 72 patients were enrolled in this study. Most of the patients were male (n=54, 75.0%), had adenocarcinoma (n=49, 68.1%). We found there was no significant correlation between the TEP-derived mRNA of PD-L1 and tumoral PD-L1 expression based on the results of the Pearson Correlation test (r=-0.19, P=0.233). Based on the median of PD-L1 mRNA, 72 patients were divided into a high PD-L1 group and a low PD-L1 group. We found that 19 patients (44.4%) responded to immunotherapy [partial response or progression-free survival (PFS) >6 months] in the high PD-L1 group, but only five patients (13.9%) responded to immunotherapy in the low PD-L1 group (P<0.01). The median PFS of the low PD-L1 group was lower than that of the high PD-L1 group (2.8 vs. 8.3 months, P<0.001). For the patients who were treated with immunotherapy alone (n=64), a similar PFS advantage was observed in the high PD-L1 group (2.8 vs. 8.0 months, P=0.002). This article presented the first data on TEP-derived PD-L1 mRNA in advanced NSCLC patients following immunotherapy and showed the potential advantage of using it as the surrogate biomarker for predicting the PFS and overall survival of patients following immunotherapy.

PD-L1 expression in resected lung adenocarcinoma: prevalence and prognostic significance in relation to the IASLC grading system.

Programmed death-ligand 1 (PD-L1) expression is a predictive biomarker for adjuvant immunotherapy and has been linked to poor differentiation in lung adenocarcinoma. However, its prevalence and prognostic role in the context of the novel histologic grade has not been evaluated. We analysed a cohort of 1233 patients with resected lung adenocarcinoma where PD-L1 immunohistochemistry (22C3 assay) was reflexively tested. Tumour PD-L1 expression was correlated with the new standardized International Association for the Study of Lung Cancer (IASLC) histologic grading system (G1, G2, and G3). Clinicopathologic features including patient outcome were analysed. PD-L1 was positive (≥1%) in 7.0%, 23.5%, and 63.0% of G1, G2, and G3 tumours, respectively. PD-L1 positivity was significantly associated with male sex, smoking, and less sublobar resection among patients with G2 tumours, but this association was less pronounced in those with G3 tumours. PD-L1 was an independent risk factor for recurrence (adjusted hazard ratio [HR] = 3.25, 95% confidence intervals [CI] = 1.93-5.48, P < 0.001) and death (adjusted HR = 2.69, 95% CI = 1.13-6.40, P = 0.026) in the G2 group, but not in the G3 group (adjusted HR for recurrence = 0.94, 95% CI = 0.64-1.40, P = 0.778). PD-L1 expression differs substantially across IASLC grades and identifies aggressive tumours within the G2 subgroup. This knowledge may be used for both prognostication and designing future studies on adjuvant immunotherapy.

Concordance among three programmed death-ligand 1 (PD-L1) scoring methods and their association with clinical outcomes of tislelizumab (TIS) monotherapy in esophageal squamous cell carcinoma (ESCC).

390 Background: Multiple scoring methods and cutoffs have been developed to evaluate tumor PD-L1 expression status in patients with ESCC, and PD-L1 expression level has been associated with the degree of response to anti-programmed cell death protein 1 (PD-1)/PD-L1 therapy. Here, we retrospectively investigated concordance between three PD-L1 scoring methods and their association with clinical outcomes in RATIONALE-302, a phase 3 study of the anti-PD-1 antibody TIS vs investigator-chosen chemotherapy (ICC) as second-line treatment for advanced unresectable/metastatic ESCC (NCT03430843). Methods: Patients enrolled in RATIONALE-302 with evaluable PD-L1 expression by the tumor area positivity (TAP) score (based on visual estimation of positive tumor cells [TCs] and tumor-associated immune cells [ICs]) using the VENTANA PD-L1 (SP263) assay were categorized at a 10% cutoff. Stained slides from those patients were rescored post hoc using both combined positive score (CPS; based on counting positive TCs and ICs) at cutoff 10 and TC (based on counting positive TCs only) score at a 1% cutoff, thresholds currently used in ESCC for anti-PD-(L)1 therapy. Concordance at these thresholds was investigated. Clinical efficacy (overall survival [OS]) for PD-L1 subgroups was assessed. Results: Of 512 pts enrolled, 364 had evaluable TAP scores (TIS, n=180; ICC, n=184), of whom 355 had evaluable post-hoc CPS and TC scores (TIS, n=175; ICC, n=180). TAP score and CPS showed high concordance in terms of overall percentage agreement (OPA; 90% [95% confidence interval (CI): 86, 93]) and Cohen’s Kappa (0.79 [95% CI: 0.72, 0.85]), while TAP and TC scores had lower concordance (OPA: 78% [95% CI: 73, 82]; Cohen’s Kappa: 0.56 [95% CI: 0.47, 0.64]). OS benefit with TIS vs ICC in PD-L1 subgroups defined by TAP, CPS, and TC score cutoffs were generally similar (Table). Conclusions: OS subgroup analysis showed comparable treatment effect by TAP score at 10% cutoff, CPS at cutoff 10, and TC score at 1% cutoff based on SP263 staining. TAP score and CPS at these cutoffs exhibited substantial concordance. The results indicate that the less time-consuming, visually estimated TAP score and CPS may be interchangeable for clinical measurement of PD-L1 expression in patients with ESCC. Clinical trial information: NCT03430843 . [Table: see text]

Meta-Analysis of Circulating Tumor Cell PD-L1 Expression and the Association with Clinical Outcomes in Non-Small Cell Lung Cancer.

Programmed death ligand-1 (PD-L1) expression on circulating tumor cells (CTCs) has been suggested to provide prognostic information in non-small cell lung cancer (NSCLC), but consensus relative to treatment outcomes is lacking. We conducted the first comprehensive meta-analysis exploring its potential as a prognostic and predictive marker, and assessed the concordance between PD-L1 + CTCs and paired tumor tissue in NSCLC patients. A comprehensive search was applied to PubMed and EMBASE to identify 26 studies that evaluated PD-L1 + CTCs and their association with survival outcomes in 1236 NSCLC patients. The meta-analysis estimated a mean PD-L1 + CTCs detection rate of 61% (95% CI, 49-72). Subgroup analysis based on treatment showed that PD-L1 + CTCs was not significantly associated with better overall survival (OS) in NSCLC patients treated with immune checkpoint inhibitors (ICIs) (Hazard Ratio (HR) = 0.96, 95% CI, 0.35-2.65, P = 0.944), but was predictive of worse OS in those treated with other therapies (HR = 2.11, 95% CI, 1.32-3.36, P = 0.002). Similarly, PD-L1 + CTCs was not significantly associated with superior progressing free survival (PFS) in NSCLCs treated with ICIs (HR = 0.67, 95% CI, 0.41-1.09, P = 0.121), but was significantly associated with shorter PFS in patients treated with other therapies (HR = 1.91, 95% CI, 1.24-2.94, P = 0.001). The overall estimate for the concordance between PD-L1 expression on CTCs and tumor cells was 63% (95% CI, 44-80). The average detection rate of PD-L1 + CTCs was comparable to the rate of PD-L1 expression in NSCLC tumors. There was a trend towards better PFS in ICI-treated NSCLC patients with PD-L1 + CTCs. Larger longitudinal studies on the association of PD-L1 + CTCs with clinical outcomes in NSCLC patients treated with ICIs are warranted.

Cervical lymphoepithelioma-like carcinoma with deficient mismatch repair and loss of SMARCA4/BRG1: a case report and five related cases

BackgroundWe encountered a cervical lymphoepithelial carcinoma (LEC) possessing a predominantly solid architecture with deficient mismatch repair (dMMR) and loss of expression of the SWI/SNF (SWItch/Sucrose Non-Fermentable) chromatin remodeling complex subunit. This is the first case report of LEC with dMMR and loss of SWI/SNF complex subunit.Case presentationA 34-year-old woman presented at our hospital with menstrual irregularities and abnormal vaginal bleeding. Magnetic resonance imaging revealed an exophytic mass in the posterior uterine cervix. Biopsy specimens confirmed squamous cell carcinoma with a 2018 International Federation of Gynecology and Obstetrics (FIGO) uterine cervical cancer stage of IB2. In a subsequent conization specimen, the tumor appeared exophytic. Microscopically, the tumor cells formed a predominant solid architecture. Abundant lymphocytic infiltration was observed. The pathological diagnosis indicated human papillomavirus (HPV)-associated squamous cell carcinoma with LEC pattern and pT1b2. Immunohistochemically, high programmed death-ligand 1 (PD-L1) expression, dMMR, and loss of the switch/sucrose non-fermentable family-related, matrix-associated, actin-dependent regulator of chromatin subfamily member 4 (SMARCA4)/BRG1, an SWI/SNF complex subunit, were observed. The patient underwent a radical hysterectomy and is alive without disease one year and five months later. Our analysis of five additional LEC cases revealed a consistent association with high-risk HPV and elevated PD-L1 expression. In addition to the present case, another patient exhibited dMMR. The SWI/SNF complex was retained except in the present case. The prognosis was favorable in all cases.ConclusionsThis unique case of LEC with dMMR suggests a distinct clinical entity with potential immunotherapy implications. Analysis of the other five LEC cases revealed that LEC was immune hot, and immune checkpoint inhibitors may be effective. The two dMMR cases showed loss of MLH1 and PMS2 expressions, and prominently high tumor PD-L1 expression. In those cases, dMMR might have contributed to the morphological characteristics of LEC.

Nivolumab plus chemotherapy in first-line metastatic non-small-cell lung cancer: results of the phase III CheckMate 227 Part 2 trial

In CheckMate 227 Part 1, first-line nivolumab plus ipilimumab prolonged overall survival (OS) in patients with metastatic non-small-cell lung cancer (NSCLC) and tumor programmed death-ligand 1 (PD-L1) expression ≥1% versus chemotherapy. We report results from CheckMate 227 Part 2, which evaluated nivolumab plus chemotherapy versus chemotherapy in patients with metastatic NSCLC regardless of tumor PD-L1 expression. Seven hundred and fifty-five patients with systemic therapy-naive, stage IV/recurrent NSCLC without EGFR mutations or ALK alterations were randomized 1 : 1 to nivolumab 360 mg every 3 weeks plus chemotherapy or chemotherapy. Primary endpoint was OS with nivolumab plus chemotherapy versus chemotherapy in patients with nonsquamous NSCLC. OS in all randomized patients was a hierarchically tested secondary endpoint. At 19.5 months' minimum follow-up, no significant improvement in OS was seen with nivolumab plus chemotherapy versus chemotherapy in patients with nonsquamous NSCLC [median OS 18.8 versus 15.6 months, hazard ratio (HR) 0.86, 95.62% confidence interval (CI) 0.69-1.08, P= 0.1859]. Descriptive analyses showed OS improvement with nivolumab plus chemotherapy versus chemotherapy in all randomized patients (median OS 18.3 versus 14.7 months, HR 0.81, 95.62% CI 0.67-0.97) and in an exploratory analysis in squamous NSCLC (median OS 18.3 versus 12.0 months, HR 0.69, 95% CI 0.50-0.97). A trend toward improved OS was seen with nivolumab plus chemotherapy versus chemotherapy, regardless of the tumor mutation status of STK11 or TP53, regardless of tumor mutational burden, and in patients with intermediate/poor Lung Immune Prognostic Index scores. Safety with nivolumab plus chemotherapy was consistent with previous reports of first-line settings. CheckMate 227 Part 2 did not meet the primary endpoint of OS with nivolumab plus chemotherapy versus chemotherapy in patients with metastatic nonsquamous NSCLC. Descriptive analyses showed prolonged OS with nivolumab plus chemotherapy in all-randomized and squamous NSCLC populations, suggesting that this combination may benefit patients with untreated metastatic NSCLC.

Development and Preclinical Evaluation of [68Ga]BMSH as a New Potent Positron Emission Tomography Tracer for Imaging Programmed Death-Ligand 1 Expression.

Immunotherapy targeting the programmed death-ligand 1 (PD-L1)/programmed cell death protein 1 (PD-1) pathway has shown remarkable efficacy against various cancers, but the overall response rate (ORR) is still low. PD-L1 expression in tumors may predict treatment response to immunotherapy. Indeed, ongoing clinical studies utilize a few PD-L1 radiotracers to assess PD-L1 expression as a predictive biomarker for immunotherapy. Here, we present a novel positron emission tomography (PET) radiotracer called [68Ga]BMSH, which is derived from a small molecule inhibitor specifically targeting the binding site of PD-L1. The inhibitor was modified to optimize its in vivo pharmacokinetic properties and enable chelation of 68Ga. In vitro evaluation revealed [68Ga]BMSH possessed a strong binding affinity, high specificity, and rapid internalization in PD-L1 overexpressing cells. Biodistribution studies showed that PD-L1 overexpressing tumors had an uptake of [68Ga]BMSH at 4.22 ± 0.65%ID/g in mice, while the number was 2.23 ± 0.41%ID/g in PD-L1 low-expressing tumors. Micro-PET/CT imaging of tumor-bearing mice further confirmed that, compared to [18F]FDG, [68Ga]BMSH can specifically identify tumors with varying levels of PD-L1 expression. Our findings suggest that the [68Ga]BMSH is a PD-L1 radioligand with ideal imaging properties, and its further application in the clinical screening of PD-L1 overexpressing tumors may improve ORR for immunotherapy.

Non-invasive PD-L1 quantification using [18F]DK222-PET imaging in cancer immunotherapy

BackgroundCombination therapies that aim to improve the clinical efficacy to immune checkpoint inhibitors have led to the need for non-invasive and early pharmacodynamic biomarkers. Positron emission tomography (PET) is a...

A novel 68Ga-labeled cyclic peptide molecular probe based on the computer-aided design for noninvasive imaging of PD-L1 expression in tumors

Programmed death-ligand 1 (PD-L1) serves as a crucial biomarker for guiding the screening of cancer patients and the stratification of immunotherapy. However, due to the high heterogeneity of tumors, the current gold standard for detecting PD-L1 expression (immunohistochemistry) fails to comprehensively evaluate the overall PD-L1 expression levels in the body. Fortunately, the use of PD-L1 targeted radiotracers enables quantitative, real-time, and noninvasive assessment of PD-L1 expression levels and dynamics in tumors. Notably, analyzing the binding mode between the precursor and the target protein to find linker binding sites that do not affect the activity of the target molecule can greatly enhance the successful development of molecular probes. This study introduced a groundbreaking cyclic peptide molecular probe called 68Ga-DOTA-PG1. It was derived from the BMS-71 cyclic peptide and was specifically designed to evaluate the expression of PD-L1 in tumors. The radiolabeling yield of 68Ga-DOTA-PG1 surpassed 97% while maintaining a radiochemical purity of over 99%. In vitro experiments demonstrated the effective targeting of PD-L1 in tumor cells by 68Ga-DOTA-PG1, with significantly higher cellular uptake observed in A375-hPD-L1 cells (PD-L1 + ) compared to A375 cells (PD-L1-). Biodistribution and PET imaging studies consistently showed specific accumulation of 68Ga-DOTA-PG1 in A375-hPD-L1 tumors, with a maximum uptake of 11.06 ± 1.70% ID/g at 2 h, significantly higher than the tumor uptake in A375 cells (1.70 ± 0.17% ID/g). These results strongly indicated that 68Ga-DOTA-PG1 held great promise as a PET radiotracer for imaging PD-L1-positive tumors.

First-line nivolumab plus ipilimumab in metastatic non-small cell lung cancer: 5-year outcomes in Japanese patients from CheckMate 227 Part 1

BackgroundIn CheckMate 227 Part 1 (NCT02477826), first-line nivolumab plus ipilimumab demonstrated long-term durable overall survival (OS) benefit versus chemotherapy in patients with metastatic non-small cell lung cancer (NSCLC), regardless of tumor programmed death ligand 1 (PD-L1) expression. We report results in Japanese patients with ≥ 5-year follow-up.MethodsAdults with stage IV/recurrent NSCLC without EGFR/ALK aberrations were randomized 1:1:1 to nivolumab plus ipilimumab, nivolumab alone, or chemotherapy (patients with tumor PD-L1 ≥ 1%), or nivolumab plus ipilimumab, nivolumab plus chemotherapy, or chemotherapy (patients with tumor PD-L1 < 1%). Five-year efficacy and safety were assessed in Japanese patients.ResultsAt 62.1 months’ minimum follow-up, 143 Japanese patients with PD-L1 ≥ 1% or < 1% were randomized to nivolumab plus ipilimumab (n = 66) or chemotherapy (n = 77). Five-year OS rates were 46% with nivolumab plus ipilimumab versus 34% with chemotherapy (PD-L1 ≥ 1%) and 36% versus 19% (PD-L1 < 1%). Median duration of response was 59.1 versus 7.1 months (PD-L1 ≥ 1%) and 17.3 versus 3.0 months (PD-L1 < 1%). Among 5-year survivors treated with nivolumab plus ipilimumab (PD-L1 ≥ 1% and < 1%; n = 27), 59% (95% CI, 39%–75%) were off treatment for ≥ 3 years without receiving subsequent therapy. No new safety signals were observed.ConclusionsAt 5-year follow-up, nivolumab plus ipilimumab continued to show long-term durable clinical benefit versus chemotherapy, regardless of tumor PD-L1 expression. Consistent with findings for the global population, these data support the use of nivolumab plus ipilimumab as first-line treatment in Japanese patients with metastatic NSCLC.

Common clinicopathological and immunological features of sarcomatoid carcinoma across organs: A histomorphology-based cross-organ study.

Sarcomatoid carcinoma (SC), which can occur in any organ, is a rare disease. To elucidate common characteristics of SC beyond organs, we evaluated clinicopathological and immunological features of SC defined by the single histological criterion beyond organs compared to randomly matched conventional carcinoma (non-SC) adjusted for the disease stage. Immunological features were assessed by multiplex immunohistochemistry, comparing immune cell density in tumor tissues and tumor programmed death-ligand 1 (PD-L1) expression. A total of 101 patients with SC or non-SC (31 lung, 19 esophagus, 22 pancreas, 15 liver, 4 bile duct, 6 kidney, 2 uterus and 2 ovary) were identified among 7197 patients who underwent surgery at our institute (1997-2020). SC was significantly associated with worse survival (HR: 1.571; 95% CI: 1.084-2.277; P = .017). The frequency of postoperative progression within 6 months was significantly higher for SC patients (54% vs 28%; P = .002). The immune profiling revealed the densities of CD8+ T cells (130 vs 72 cells/mm2 ; P = .004) and tumor-associated macrophages (566 vs 413 cells/mm2 ; P < .0001) and the tumor PD-L1 expression score (40% vs 5%; P < .0001) were significantly higher in SCs than in non-SCs. Among 73 SC patients with postoperative progression, multivariate Cox regression analysis showed that immunotherapy tended to be associated with favorable survival (HR: 0.256; 95% CI: 0.062-1.057; P = .060). Collectively, SCs shared clinicopathological and immunological features across organs. Our study can initiate to standardize the pathological definition of SC and provide a rationale for the investigation and development for this rare disease in a cross-organ manner.

Preparation and Application of a Bioorganic Nanoparticle-Enhanced PDL1-Targeted Small-Molecule Probe.

Programmed death ligand 1 (PDL1) is a specific molecular target for the diagnosis and immunotherapy of solid tumors. PET imaging can be used for noninvasive assessments of PDL1 expression in tumors to aid in therapy selection. The most frequently reported small-molecule radiotracer of PDL1 is limited by low imaging specificity, short residence time, and singular functionality. Here, we combined a biocompatible melanin nanoprobe with the PDL1-binding peptide WL12 to construct a novel radiotracer, 124I-WPMN, to enhance PDL1 targeting. The radiochemical purity of 124I-WPMN was >95%, and uptake in A549PDL1 cells was 1.49 ± 0.08% at 2 h. The uptake was blocked by WL12 (0.39 ± 0.03%, P < 0.0001). This novel radiotracer showed a higher affinity for PDL1 (Kd = 18.5 nM) than 68Ga-NOTA-WL12 (Kd = 24.0 nM). Micro-PET/CT imaging demonstrated specific uptake and a high signal-to-noise ratio in an A549PDL1 xenograft mouse model with a tumor-to-muscle ratio of 27.31 ± 7.03 at 2 h. The levels increased or remained steady for more than 72 h, and tumor uptake was significantly higher than 68Ga-NOTA-WL12, at 6.08 ± 0.62 at 2 h. Prolonged retention of 124I-WPMN makes it possible to conduct PET/MRI imaging over long periods and to perform various imaging techniques. A clear advantage of 124I-WPMN over 68Ga-NOTA-WL12 was observed for PDL1-targeted PET imaging after nanoparticle modification, supporting the utility of 124I-WPMN PET imaging as an effective diagnostic tool for optimizing PDL1-targeted therapies.

Therapeutic blocking of VEGF binding to neuropilin-2 diminishes PD-L1 expression to activate antitumor immunity in prostate cancer.

Prostate cancers are largely unresponsive to immune checkpoint inhibitors (ICIs), and there is strong evidence that programmed death-ligand 1 (PD-L1) expression itself must be inhibited to activate antitumor immunity. Here, we report that neuropilin-2 (NRP2), which functions as a vascular endothelial growth factor (VEGF) receptor on tumor cells, is an attractive target to activate antitumor immunity in prostate cancer because VEGF-NRP2 signaling sustains PD-L1 expression. NRP2 depletion increased T cell activation in vitro. In a syngeneic model of prostate cancer that is resistant to ICI, inhibition of the binding of VEGF to NRP2 using a mouse-specific anti-NRP2 monoclonal antibody (mAb) resulted in necrosis and tumor regression compared with both an anti-PD-L1 mAb and control immunoglobulin G.This therapy also decreased tumor PD-L1 expression and increased immune cell infiltration. We observed that the NRP2, VEGFA, and VEGFC genes are amplified in metastatic castration-resistant and neuroendocrine prostate cancer. We also found that individuals with NRP2High PD-L1High metastatic tumors had lower androgen receptor expression and higher neuroendocrine prostate cancer scores than other individuals with prostate cancer. In organoids derived from patients with neuroendocrine prostate cancer, therapeutic inhibition of VEGF binding to NRP2 using a high-affinity humanized mAb suitable for clinical use also diminished PD-L1 expression and caused a substantial increase in immune-mediated tumor cell killing, consistent with the animal studies. These findings provide justification for the initiation of clinical trials using this function-blocking NRP2 mAb in prostate cancer, especially for patients with aggressive disease.

Abstract 5151: Enzalutamide resistance results in immunosuppressive alterations in prostate tumor immune microenvironment

Abstract Background: Emerging data suggested that enzalutamide-treated prostate cancer patients with increased programmed death-ligand 1 (PD-L1) expression may benefit from anti-PD-L1 treatment. Unfortunately, the Phase III IMbassador250 trial revealed that the combination of atezolizumab (PD-L1 inhibitor) and enzalutamide failed to extend overall survival in patients with castration-resistant prostate cancer (CRPC). The mechanisms underlying treatment failure remain unknown. In this study, we investigated the regulation of immunosuppressive signaling in enzalutamide resistant prostate cancer and characterized the immune infiltrating cells in murine prostate tumors. Methods: The expression of interferon gamma-related genes was determined using qRT-PCR and/or western blotting. Androgen receptor (AR) and AR-V7 levels were downregulated using specific siRNA. Myc-CaP cells were chronically exposed to increasing concentrations of enzalutamide (5-50 μM) for &amp;gt;12 months, and the cells resistant to enzalutamide were referred to as Myc-CaP MDVR. The gene-regulating mechanisms in drug-resistant prostate cancer cells were determined by RNA sequencing analyses. Myc-CaP and Myc-CaP MDVR xenograft tumors were established in FVB mice, and tumor-infiltrating lymphocytes were isolated using Ficoll. The stained immune cells were determined by flow cytometry, and the data were analyzed using Flowjo. Results: Immune-related signaling pathways (interferon alpha/gamma response, T cell activation, and cell chemotaxis pathways) were suppressed in C4-2B MDVR cells. However, PD-L1 expression was highly upregulated and negatively regulated by AR in C4-2B MDVR cells. Enzalutamide treatment decreased CD8+ T cell but increased monocytic myeloid-derived suppressor cell (M-MDSC) population and PD-L1 expression in murine Myc-CaP tumors. Consistently, chemotaxis and immune response-regulating signaling pathways were suppressed, and PD-L1 expression was increased in enzalutamide-resistant Myc-CaP MDVR cells. Notably, MDSC populations were significantly increased in Myc-CaP MDVR orthotopic tumors compared with those in Myc-CaP parental tumors. Co-culturing bone marrow cells with Myc-CaP MDVR cells significantly promoted MDSC differentiation and polarized macrophages from the M1 to M2 phase. Conclusions: Immunosuppressive signaling is activated in enzalutamide resistant prostate cancer cells. The activated immune-related signatures involved in T cells, MDSC, and macrophages may reduce the efficacy of immune checkpoint inhibitors in enzalutamide-resistant prostate cancer. Grant Support: This work was supported in part by grants NIH/NCI R37CA249108 (C, Liu) and R01CA251253 (C, Liu). Citation Format: Pengfei Xu, Joy C. Yang, Bo Chen, Christopher Nip, Jonathan E. Van Dyke, Christopher P. Evans, William J. Murphy, Chengfei Liu. Enzalutamide resistance results in immunosuppressive alterations in prostate tumor immune microenvironment. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 5151.

Abstract 3294: Development and validation of an AI-based PD-L1 scoring algorithm in NSCLC samples

Abstract Introduction: Lung cancer is the leading cause of cancer-related mortality worldwide, with non-small cell lung cancer (NSCLC) accounting for over 80% of all cases (1). The survival rate of patients with NSCLC is poor, with an overall 5-year survival rate of less than 30% (2). Programmed death-ligand 1 (PD-L1) expression on tumor cells is a response predictor to immune checkpoint inhibitor therapy and has become a cornerstone of first-line therapy for patients with advanced NSCLC without targetable alterations (3). However, poor inter- and intra-observer concordance when reporting PD-L1 expression might imply patients receive suboptimal treatment (4). Here, we present an AI-based algorithm for the clinical scoring of tumor PD-L1 expression in NSCLC samples to support pathologists and increase scoring consistency. Methods: HALO PD-L1 AI was developed and validated on a subset of routine diagnostic cases stained with the SP263 PD-L1 clone. To obtain the whole slide percentage of PD-L1 tumor positive cells and report the tumor proportion score (TPS), a ResNet 18-based network was trained with 141354 expert annotations to classify cells as ‘PD-L1 tumor positive’, ‘PD-L1 tumor negative’, or as ‘other’. Prior to PD-L1 cell classification, the algorithm automatically removes artifacts and segments the tissue into tumor and benign regions. The algorithm was validated by comparing the TPS score from three pathologists with the TPS score obtained from HALO PD-L1 AI on 203 whole slide images. Results: The three pathologists were in complete agreement in 64.0% of the cases. In pairwise comparisons, percent agreement ranged from 74.9% to 77.3%. Agreement of HALO PD-L1 AI with the pathologists’ mode was 73.4% overall, with specific agreement at the clinically relevant cut-offs ranging from 0.71 to 0.78. Intraclass correlation coefficient (ICC) between HALO PD-L1 AI and pathologists’ TPS scores was 0.95 (95% confidence interval 0.93 - 0.97). Conclusions: HALO PD-L1 AI is in agreement with pathologist TPS scores in routine diagnostic cases. Usage of HALO PD-L1 AI in a diagnostic setting has the potential to support pathologists scoring PD-L1, saving pathologists’ time and ensuring consistency in the reported results.

Evaluation of Programmed Death - Ligand 1 (Pd-L1) Expression in Head and Neck Squamous Cell Carcinoma.

Head and Neck Squamous Cell Carcinoma (HNSCC) is a highly frequent malignancy worldwide and is also the leading cause of death. The prognosis for individuals with HNSCC remains dismal, with a five-year survival rate of less than 50%. The novel anti-PD-L1 immunotherapy is found to be promising, and immunohistochemistry (IHC) has been established as a reliable method for patient stratification. We intend to evaluate the prognostic significance of the expression of programmed death ligand-1 (PD-L1) in HNSCC and determine its association with clinicopathological variables. A total of 50 cases of biopsy-confirmed HNSCC were studied in a tertiary hospital between Dec 2020 and June 2022. The specimens were tested for PD-L1 IHC expression with antibody clone CAL-10 (Biocare) and scored by Combined Positive Score (CPS). The association between PD-L1 expression and clinicopathological variables was evaluated. PD-L1 was positive in 92% of the cases, and a significant association (P= 0.024) was seen between PD-L1 expression and tumor-infiltrating lymphocytes (TILs). PD-L1 did not show any significant association with patient demographics, tumor site, grade, or stage. In the present study, evaluation of the immunohistochemical expression of PD-L1 on the tumor cells and TILs in HNSCC revealed a high prevalence of PD-L1 expression. PD-L1 IHC studies for patient selection for immunotherapy would be a promising technique. Frequent PD-L1 expression in tumors with significant TILs may be useful in identifying patients who may benefit from anti-PD-1/PD-L1 therapy.

MP20-11 ENZALUTAMIDE RESISTANCE RESULTS IN IMMUNOSUPPRESSIVE ALTERATIONS IN PROSTATE TUMOR IMMUNE MICROENVIRONMENT

You have accessJournal of UrologyCME1 Apr 2023MP20-11 ENZALUTAMIDE RESISTANCE RESULTS IN IMMUNOSUPPRESSIVE ALTERATIONS IN PROSTATE TUMOR IMMUNE MICROENVIRONMENT Pengfei Xu, Joy C. Yang, Bo Chen, Christopher Nip, Jonathan E Van Dyke, Christopher P. Evans, William J. Murphy, and Chengfei Liu Pengfei XuPengfei Xu More articles by this author , Joy C. YangJoy C. Yang More articles by this author , Bo ChenBo Chen More articles by this author , Christopher NipChristopher Nip More articles by this author , Jonathan E Van DykeJonathan E Van Dyke More articles by this author , Christopher P. EvansChristopher P. Evans More articles by this author , William J. MurphyWilliam J. Murphy More articles by this author , and Chengfei LiuChengfei Liu More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003245.11AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Emerging data suggested that enzalutamide-treated prostate cancer patients with increased programmed death-ligand 1 (PD-L1) expression may benefit from anti-PD-L1 treatment. Unfortunately, the Phase III IMbassador250 trial revealed that the combination of atezolizumab (PD-L1 inhibitor) and enzalutamide failed to extend overall survival in patients with castration-resistant prostate cancer (CRPC). The mechanisms underlying treatment failure remain unknown. In this study, we investigated the regulation of immunosuppressive signaling in enzalutamide resistant prostate cancer and characterized the immune infiltrating cells in murine prostate tumors. METHODS: The expression of interferon gamma-related genes was determined using qRT-PCR and/or western blotting. Androgen receptor (AR) and AR-V7 levels were downregulated using specific siRNA. Myc-CaP cells were chronically exposed to increasing concentrations of enzalutamide (5-50 μM) for >12 months, and the cells resistant to enzalutamide were referred to as Myc-CaP MDVR. The gene-regulating mechanisms in drug-resistant prostate cancer cells were determined by RNA sequencing analyses. Myc-CaP and Myc-CaP MDVR xenograft tumors were established in FVB mice, and tumor-infiltrating lymphocytes were isolated using Ficoll. The stained immune cells were determined by flow cytometry, and the data were analyzed using Flowjo. RESULTS: Immune-related signaling pathways (interferon alpha/gamma response, T cell activation, and cell chemotaxis pathways) were suppressed in C4-2B MDVR cells (p<0.001). However, PD-L1 expression was highly upregulated and negatively regulated by AR in C4-2B MDVR cells. Enzalutamide treatment decreased CD8+ T cell (14.8% vs. 10.3%, p<0.05) but increased monocytic myeloid-derived suppressor cell (M-MDSC) population (23.0% vs. 34.2%, p<0.05) and PD-L1 expression in murine Myc-CaP tumors. Consistently, chemotaxis and immune response-regulating signaling pathways were suppressed, and PD-L1 expression was increased in enzalutamide-resistant Myc-CaP MDVR cells. Notably, MDSC populations were significantly increased in Myc-CaP MDVR orthotopic tumors compared with those in Myc-CaP parental tumors (4.0% vs. 1.6%, p<0.01). Co-culturing bone marrow cells with Myc-CaP MDVR cells significantly promoted MDSC differentiation and polarized macrophages from the M1 to M2 phase. CONCLUSIONS: Immunosuppressive signaling is activated in enzalutamide resistant prostate cancer cells. The activated immune-related signatures involved in T cells, MDSC, and macrophages may reduce the efficacy of immune checkpoint inhibitors in enzalutamide-resistant prostate cancer. Source of Funding: This work was supported in part by grants NIH/NCI R37CA249108 (C, Liu) and R01CA251253 (C, Liu) © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e279 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Pengfei Xu More articles by this author Joy C. Yang More articles by this author Bo Chen More articles by this author Christopher Nip More articles by this author Jonathan E Van Dyke More articles by this author Christopher P. Evans More articles by this author William J. Murphy More articles by this author Chengfei Liu More articles by this author Expand All Advertisement PDF downloadLoading ...

Remodeling Tumor Immunogenicity with Dual-Activatable Binary CRISPR Nanomedicine for Cancer Immunotherapy.

The specific recognition of cancer cells by the body's immune system is an essential step in initiating antitumor immunity. However, the decreased expression of major histocompatibility complex class I (MHC-1) and overexpression of programmed death ligand 1 (PD-L1) causes insufficient tumor-associated antigens presentation and inactivation of T cells, which accounts for poor immunogenicity. To remodel tumor immunogenicity, herein, a dual-activatable binary CRISPR nanomedicine (DBCN) that can efficiently deliver a CRISPR system into tumor tissues and specifically control its activation is reported. This DBCN is made of a thioketal-cross-linked polyplex core and an acid-detachable polymer shell, which can maintain stability during blood circulation, while detaching a polymer shell to facilitate the cellular internalization of the CRISPR system after entering tumor tissues and ultimately activating gene editing under exogenous laser irradiation, thereby maximizing the therapeutic benefits and reducing potential safety concerns. With the collaborative application of multiple CRISPR systems, DBCN efficiently corrects both dysregulation of MHC-1 and PD-L1 expression in tumors, thus initiating robust T cell-dependent antitumor immune responses to inhibit malignant tumor growth, metastasis, and recurrence. Given the increasing abundance of CRISPR toolkits, this research provides an appealing therapeutic strategy and a universal delivery platform to develop more advanced CRISPR-based cancer treatments.