PD-L1 Immunohistochemistry Assays for Lung Cancer: Results from Phase 1 of the Blueprint PD-L1 IHC Assay Comparison Project

Immunotherapy Guided by Immunohistochemistry PD-L1 Testing for Patients with NSCLC: A Microsimulation Model-Based Effectiveness and Cost-Effectiveness Analysis

BACKGROUND

On the basis of immunohistochemistry PD-L1 testing results, patients with advanced non-small cell lung cancer (NSCLC) are treated differently. Theoretically, patients with high PD-L1 expression (50% or 1%) should receive PD-1 monotherapy for fewer adverse reactions and cost savings from avoiding chemotherapy; however, there is controversy surrounding the cut-off criteria (1% or 50%) for immunohistochemistry testing and threshold for PD-1 monotherapy.

OBJECTIVE

This study aims to predict the effectiveness and cost-effectiveness of different immunotherapy strategies for patients with NSCLC in China from the healthcare system perspective.

PATIENTS AND METHODS

A microsimulation model was developed to evaluate the effectiveness and cost-effectiveness of three treatment strategies: PD-L1 testing (1%) (PD-1 monotherapy for those with PD-L1 expression at 1% threshold, and combination with chemotherapy for others with immunohistochemistry testing), PD-L1 testing (50%) (PD-1 monotherapy for those with PD-L1 expression at 50% threshold, and combination with chemotherapy for others with immunohistochemistry testing), and No PD-L1 testing (PD-1 combined with chemotherapy without immunohistochemistry testing). The model assumed 1000 patients per strategy, with each patient entering a unique clinical path prior to receiving treatment on the basis of PD-L1 test results. Clinical inputs were derived from clinical trials. Cost and utility parameters were obtained from the database and literature. One-way probabilistic sensitivity analyses (PSA) and six scenario analyses were used to test the model's robustness.

RESULTS

The study revealed a hierarchy of survival benefits across three strategies, with No PD-L1 testing demonstrating the most survival advantage, followed by PD-L1 testing (50%), and finally, PD-L1 testing (1%). The comparative analysis demonstrated that No PD-L1 testing significantly enhanced overall survival (OS) (HR 0.85, 95% CI 0.78-0.93), progression-free survival (HR 0.82, 95% CI 0.75-0.90), and progression-free2 survival (PFS2) (HR 0.91, 95% CI 0.83-0.99) when juxtaposed against PD-L1 testing (1%). However, these improvements were not as pronounced when compared with PD-L1 testing (50%), particularly in relation to PFS, PFS2, and OS. The cost-effectiveness analysis further unveiled incremental cost-utility ratios (ICUR), with No PD-L1 testing versus PD-L1 testing (50%) at $34,003 per quality-adjusted life year (QALY) and No PD-L1 testing versus PD-L1 testing (1%) at $34,804 per QALY. In parallel, the ICUR for PD-L1 testing (50%) versus PD-L1 testing (1%) stood at $35,713 per QALY. Remarkably, the PSA result under a willingness-to-pay (WTP) threshold of $10,144 per QALY, with a 100% probability, demonstrated PD-L1 testing (1%) as the most cost-effective option.

CONCLUSIONS

The survival benefits of PD-1 monotherapy for high expression with PD-L1 immunohistochemistry testing are inferior to those of PD-1 combined with chemotherapy without testing, but it is found to be more cost-effective at the WTP thresholds in China and holds great potential in increasing affordability and reducing the economic burden.

Functional Flow Cytometry to Predict PD-L1 Conformational Changes

The programmed cell death protein 1/programmed cell death protein ligand 1 (PD-1/PD-L1) axis is one of the most widely recognized targets for cancer immunotherapy. Importantly, PD-L1 conformational changes can hinder target binding when living cells are used. Antibody affinity, equilibrium binding, association and dissociation rates, and other affinity-related constants are fundamental to ensure target saturation. Here, PD-L1 changes in conformation and their potential impact on PD-L1 function and mutation are explored. Specifically, we present detailed flow cytometry procedures to analyze PD-L1 reactivity in myeloid-derived suppressor cells (MDSCs). This approach can also be used to study the contribution of protein conformational changes in living cells. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Sample preparation for PD-L1+ myeloid-derived suppressor cells detection by flow cytometry Basic Protocol 2: Protocol preparation, sample acquisition, and gating strategy for flow cytometric screening of PD-L1+ myeloid-derived suppressor cells in patients with lung cancer Support Protocol 1: Bioinformatic tools for the analysis of flow cytometric data.

Tumor mutation burden in the prognosis and response of lung cancer patients to immune-checkpoint inhibition therapies

Immune checkpoint inhibition (ICI) therapies have reshaped the therapeutic landscape in lung cancer management, providing first-time improvements in patient response, prognosis, and overall survival. Despite their clinical effectiveness, variability in treatment responsiveness, as well as drug resistance, have led to a compelling need for predictive biomarkers facilitating the individualized selection of the most efficient therapeutic approach. Significant progress has been made in the identification of such biomarkers, with tumor mutation burden (ΤΜΒ) appearing as the leading and most promising predictive biomarker for the efficacy of ICIs in non-small cell lung cancer (NSCLC) among other tumors. Anti-PD-1/PD-L1 and anti-CTLA-4 antibodies have been extensively studied and clinically utilized. However, the overall efficiency of these drugs remains unsatisfactory, urging for the investigation of novel inhibitors, such as those targeting LAG-3, TIM-3, TIGIT and VISTA, which could be used either as a monotherapy or synergistically with the PD-1/PD-L1 or CTLA-4 blockers. Here, we investigate the role of TMB and cancer neoantigens as predictive biomarkers in the response of lung cancer patients to different ICI therapies, specifically focusing on the most recent immune checkpoint inhibitors, against LAG-3, TIM-3, TIGIT and VISTA. We further discuss the new trends in immunotherapies, including CAR T-cell therapy and personalized tumor vaccines. We also review further potential biomarkers that could be used in lung cancer response to immunotherapy, such as PD-L1+ IHC, MSI/dMMR, tumor infiltrating lymphocytes (TILs), as well as the role of the microbiome and circulating tumor DNA (ctDNA). Finally, we discuss the limitations and challenges of each.

Discordance in PD-L1 expression using 22C3 and SP142 assays between primary and metastatic triple-negative breast cancer

AIMS

SP142 and 22C3 assays are approved companion diagnostic assays for anti-PD-1/PD-L1 therapy selection in metastatic triple-negative breast cancer (TNBC). The discordance in PD-L1 status between primary and metastatic tumors in the same patient has been poorly characterized. Here, we examined the concordance of PD-L1 status between the two assays and between primary tumors and metastases for each assay.

METHODS

We retrospectively evaluated tumor samples from 160 patients with TNBC, including 45 patients with paired primary and metastatic tumors. PD-L1 status was assessed using SP142 and 22C3 assays, to determine the immune cell (IC) score, tumor cell (TC) score (SP142 and 22C3), and combined proportion score (CPS: 22C3).

RESULTS

The concordance of PD-L1 positivity at diagnostic cutoffs for SP142 (IC ≥ 1) and 22C3 (CPS ≥ 10) was substantial (κ = 0.80) in primary tumors and moderate (κ = 0.60) in metastatic tumors. In comparison, between primary and metastatic tumors, the concordance with 22C3 was moderate (κ = 0.50), whereas that with SP142 was poor (κ = -0.03). Among patients who were PD-L1 negative for both assays in primary tumors, 7/30 (23.3%) were PD-L1 positive for both or either 22C3 or SP142 in the metastatic tumors.

CONCLUSIONS

The inter-assay concordance of PD-L1 positivity at diagnostic cutoffs was substantial in primary tumors and moderate in metastatic tumors. Discordance between PD-L1 status in primary and metastatic tumors was frequently observed, especially with SP142. Some patients with a PD-L1-negative status in primary tumors may still be candidates for immunotherapy, depending on the PD-L1 status in their metastatic tumors.

Immunotherapy-related biomarkers: Confirmations and uncertainties

Immunotherapy profoundly changed oncology treatment, becoming one of the main therapeutical strategies. Remarkable improvement has been achieved in survival outcomes, but the percentage of patients who benefit from immunotherapy is still limited. Only one-third of patients receiving immune checkpoint inhibitors (ICIs) achieve long-term response. Several patients are not responsive to treatment or relapse after an initial response. To date, programmed death-ligand 1, microsatellite instability, and tumor mutational burden are the three biomarkers validated to predict the ICIs response, but a single variable seems still insufficient in the patient's selection. Considering the substantial and increasing use of these drugs, the identification of new predictive biomarkers of ICI response is of paramount importance. We summarize the state of the art and the clinical use of immune biomarkers in oncology, highlighting the strength and weaknesses of currently approved biomarkers, describing the emerging tissues and circulating biomarkers, and outlining future perspectives.

Assessing PD-L1 Expression in Head and Neck Squamous Cell Carcinoma: Trials and Tribulations

Immune checkpoint inhibitors have improved the outcome of patients diagnosed with inoperable recurrent or metastatic head and neck squamous cell carcinoma. However, as only a subset of head and neck cancer patients benefit from this treatment, biomarkers predicting treatment response help guide physicians in their clinical decision-making. PD-L1 expression assessed by immunohistochemistry is the single most clinically relevant biomarker predicting response to PD-1-blocking antibodies. Here, we discuss in which clinical context assessment of PD-L1 expression is instrumental for the choice of therapy, how pathologists score it, and how it affects the approval of anti-PD-1 antibodies. Furthermore, we discuss the heterogeneity of PD-L1 expression and review technical aspects of determining this prominent biomarker-knowledge that might influence clinical decision-making.

The clinicopathological features of BRG1-deficient non-small cell lung cancer and its response to immunotherapy: A single-center retrospective study

PURPOSE

BRG1-deficient NSCLCs have been more intriguing recently for its highly aggressive clinical behavior and no effective therapies. This study characterized the clinical and pathological features of BRG1-deficient NSCLCs and investigated their response to immunotherapy.

METHODS

Forty-seven cases with BRG1-deficient NSCLC were included. Immunohistochemical markers such as BRG1, CK7, TTF-1, NapsinA, P40, HepPar-1, Ki-67, BRM, ARID1A and ARID1B were stained. Additionally, the PD-L1 expression level, overall survival, progression-free survival and disease control rate of patients received immunotherapy were evaluated.

RESULTS

This study revealed that: (1) Patients with BRG1-deficient NSCLC have a male predominance (89.4 %), smoker enrichment (76.6 %) and poor prognosis (median OS: 7.0 months for advanced stage). (2) Histologically, BRG1-deficient NSCLCs presented significant morphological diversity and no lepidic pattern. Inflammatory infiltration and tumor necrosis was a prominent feature. Immunohistochemical analyses showed a distinctive uniform immunophenotype (TTF-1-/NapsinA-/CK7+) in 60.9 % (28/46) of cases and HepPar-1 positive in 46.5 % (20/43) of cases. BRM loss or significant reduction coexisted in 11.8 % (4/34) of cases. No case (0/37) showed loss of ARID1A or ARID1B. (3) Eight patients with advanced tumor stage had received immunotherapy and 4 cases achieved a sustainable clinical response with the disease control rate of 50 %.

CONCLUSION

BRG1-deficient NSCLC showed diverse histopathological patterns and a unique immunohistochemical phenotype. ICIs-based immunotherapy is a promising therapy needs to be investigated further for BRG1- deficient NSCLC.

A phase 2 trial of durvalumab treatment following radiation monotherapy in patients with non-small cell lung cancer ineligible for stage III chemoradiotherapy: The SPIRAL-RT study

BACKGROUND

Although concurrent chemoradiotherapy (CCRT) followed by durvalumab is the standard treatment for patients with stage III non-small cell lung cancer (NSCLC), only half of the patients are allowed to receive CCRT in real-world settings. We evaluated the efficacy and safety of durvalumab after radiation monotherapy for NSCLC patients who are ineligible for chemoradiotherapy.

METHODS

A single-arm, prospective, open-label, multicenter phase II trial was conducted in Japan. The patients received radiation (54-66 Gy) followed by durvalumab (10 mg/kg every 2 weeks for up to 12 months). The primary endpoint was the 1-year progression-free survival (PFS) rate. The secondary endpoints were the objective response rate (ORR), PFS, overall survival (OS), and safety.

RESULTS

Between September 2019 and April 2021, 33 patients were enroled from eight institutions. The median patient age was 79 years, and the majority of patients were male (78.8%). The 1-year PFS rate was 39.1% (90% confidence interval [CI]: 24.7-54.6%). Three patients (9.1%) had a performance status of 2. The ORR was 42.4% (95% CI: 27.2-59.2%). The median PFS and OS were 8.9 (95% CI: 7.4-19.4) and 20.8 (95% CI: 15.8-not estimable) months, respectively. The most common adverse event was radiation pneumonitis (51.5%). The median treatment duration was 6.4 (range: 0.50-12.0) months for durvalumab. At the endpoint, 30.3% (10/33) of the patients had completed 1 year of durvalumab therapy.

CONCLUSIONS

Durvalumab is an effective treatment with tolerable toxicity following radiation monotherapy in stage III NSCLC patients who are ineligible for chemoradiotherapy.

TRIAL REGISTRATION

JMA-IIA00434 (jRCT).

Real-world prevalence of PD-L1 expression in non-small cell lung cancer: an Australia-wide multi-centre retrospective observational study

An investigator-initiated, Australia-wide multi-centre retrospective observational study was undertaken to investigate the real-world prevalence of programmed death ligand-1 (PD-L1) expression in non-small cell lung carcinoma (NSCLC). Multiple centres around Australia performing PD-L1 immunohistochemistry (IHC) were invited to participate. Histologically confirmed NSCLC of any stage with a PD-L1 IHC test performed for persons aged ≥18 years between 1 January 2018 and 1 January 2020, and eligible for review, were identified at each centre, followed by data extraction and de-identification, after which data were submitted to a central site for collation and analysis. In total data from 6690 eligible PD-L1 IHC tests from histologically (75%) or cytologically (24%) confirmed NSCLC of any stage were reviewed from persons with a median age of 70 years, 43% of which were female. The majority (81%) of tests were performed using the PD-L1 IHC SP263 antibody with the Ventana BenchMark Ultra platform and 19% were performed using Dako PD-L1 IHC 22C3 pharmDx assay. Reported PD-L1 tumour proportion score (TPS) was ≥50% for 30% of all tests, with 62% and 38% scoring PD-L1 ≥1% and <1%, respectively. Relative prevalence of clinicopathological features with PD-L1 scores dichotomised to <50% and ≥50%, or to <1% and ≥1%, were examined. Females scored ≥1% slightly more often than males (64% vs 61%, respectively, p=0.013). However, there was no difference between sexes or age groups (<70 or ≥70 years) where PD-L1 scored ≥50%. Specimens from patients with higher stage (III/IV) scored ≥1% or ≥50% marginally more often compared to specimens from patients with lower stage (I/II) (p≤0.002). Proportions of primary and metastatic specimens did not differ where PD-L1 TPS was ≥1%, however more metastatic samples scored TPS ≥50% than primary samples (metastatic vs primary; 34% vs 27%, p<0.001). Cytology and biopsy specimens were equally reported, at 63% of specimens, to score TPS ≥1%, whereas cytology samples scored TPS ≥50% slightly more often than biopsy samples (34% vs 30%, respectively, p=0.004). Resection specimens (16% of samples tested) were reported to score TPS ≥50% or ≥1% less often than either biopsy or cytology samples (p<0.001). There was no difference in the proportion of tests with TPS ≥1% between PD-L1 IHC assays used, however the proportion of tests scored at TPS ≥50% was marginally higher for 22C3 compared to SP263 (34% vs 29%, respectively, p<0.001). These real-world Australian data are comparable to some previously published global real-world data, with some differences noted.

Novel nomogram for predicting survival in advanced non-small cell lung cancer receiving anti-PD-1 plus chemotherapy with or without antiangiogenic therapy

Background

This study aimed to develop and validate a novel nomogram to predict survival in advanced non-small cell lung cancer (NSCLC) receiving programmed cell death 1 (PD-1) inhibitor plus chemotherapy with or without antiangiogenic therapy.

Methods

A total of 271 patients with advanced NSCLC who received anti-PD-1 plus chemotherapy with or without antiangiogenic therapy were enrolled in our center and randomized into the training cohort (n = 133) and the internal validation cohort (n = 138). Forty-five patients from another center were included as an independent external validation cohort. The nomogram was created based on the multivariate Cox regression analysis to predict overall survival (OS) and progression-free survival (PFS). The performance of the nomogram was assessed using the concordance index (C-index), the time-dependent area under the receiver operating (ROC) curves (AUCs), calibration curves, and decision curve analysis (DCA).

Results

Four factors significantly associated with OS were utilized to create a nomogram to predict OS: Eastern Cooperative Oncology Group performance status (ECOG PS), programmed cell death-ligand 1 (PD-L1) expression, chemotherapy cycle, and pretreatment lactate dehydrogenase-albumin ratio (LAR). Six variables significantly associated with PFS were incorporated into the development of a nomogram for predicting PFS: ECOG PS, histology, PD-L1 expression, chemotherapy cycle, pretreatment platelet to lymphocyte (PLR), and pretreatment LAR. The C-indexes of the nomogram for predicting OS and PFS were 0.750 and 0.747, respectively. The AUCs for predicting the 6-month, 12-month, and 18-month OS and PFS were 0.847, 0.791, and 0.776 and 0.810, 0.787, and 0.861, respectively. The calibration curves demonstrated a good agreement between predictions and actual observations. The DCA curves indicated that the nomograms had good net benefits. Furthermore, the nomogram model was well-validated in the internal and external cohorts.

Conclusion

The novel nomogram for predicting the prognosis of advanced NSCLC receiving anti-PD-1 plus chemotherapy with or without antiangiogenic therapy may help guide clinical treatment decisions.

Granzyme B (GZMB)-Positive Tumor-Infiltrating Lymphocytes in Lung Adenocarcinoma: Significance as a Prognostic Factor and Association with Immunosuppressive Proteins

BACKGROUND

Granzyme B (GZMB) is a serine protease produced by cytotoxic lymphocytes that reflects the activity of anti-tumor immune responses in tumor-infiltrating lymphocytes (TILs); however, the prognostic significance of GZMB+ TILs in lung adenocarcinoma is poorly understood.

METHODS

We analyzed 273 patients with pathological stage (pStage) I-IIIA lung adenocarcinoma who underwent surgery at Kyushu University from 2003 to 2012. We evaluated GZMB+ TIL counts by immunohistochemistry. We set the cut-off values at 12 cells/0.04 mm2 for GZMB+ TILs and divided the patients into GZMB-High (n = 171) and GZMB-Low (n = 102) groups. Then, we compared the clinicopathological characteristics of the two groups and clinical outcomes. Programmed cell death ligand-1 (PD-L1) and indoleamine 2,3-dioxygenase 1 (IDO1) expression in tumor cells was also evaluated, and combined prognostic analyses of GZMB+ TILs with PD-L1 or IDO1 were performed.

RESULTS

GZMB-Low was significantly associated with pStage II-III, PD-L1 positivity, and IDO1 positivity. Disease-free survival (DFS) and overall survival (OS) in the GZMB-Low group were significantly worse than in the GZMB-High group. In multivariable analysis, GZMB-Low was an independent prognostic factor for both DFS and OS. Furthermore, combined prognostic analyses of GZMB+ TILs with PD-L1 or IDO1 showed that GZMB-Low with high expression of these immunosuppressive proteins had the worst prognosis.

CONCLUSIONS

We analyzed GZMB+ TIL counts in lung adenocarcinoma and elucidated its prognostic significance and association with PD-L1 and IDO1. GZMB+ TIL counts might reflect the patient's immunity against cancer cells and could be a useful prognostic marker of lung adenocarcinoma.

Expression Changes in Programmed Death Ligand 1 from Precancerous Lesions to Invasive Adenocarcinoma in Subcentimeter Pulmonary Nodules: A Large Study of 2022 Cases in China

PURPOSE

This large-scale, multicenter, retrospective observational study aimed to evaluate the clinicopathological and molecular profiles associated with programmed death-ligand 1 (PD-L1) expression in precancerous lesions and invasive adenocarcinoma in subcentimeter pulmonary nodules.

PATIENTS AND METHODS

Patients with histologically confirmed atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), and invasive adenocarcinoma (ADC) were included. PD-L1 expression was evaluated at each center using a PD-L1 immunohistochemistry 22C3 pharmDx kit (Agilent, Santa Clara, CA, USA). The tumor proportion score (TPS) cutoff values were set at ≥ 1% and ≥ 50%.

RESULTS

A total of 2022 nodules from 1844 patients were analyzed. Of these, 9 (0.45%) nodules had PD-L1 TPS ≥ 50%, 187 (9.25%) had PD-L1 TPS 1-49%, and 1826 (90.30%) had PD-L1 TPS < 1%. A total of 378 (18.69%), 1016 (50.25%), and 628 (31.06%) nodules were diagnosed as AAH/AIS, MIA, and ADC, respectively, by pathology. A total of 1377 (68.10%), 591 (25.67%), and 54 (2.67%) nodules were diagnosed as pure ground-glass opacity (GGO), mixed GGO, and solid nodules, respectively, by computed tomography. There was a significant difference between PD-L1 expression and anaplastic lymphoma kinase (ALK) mutation status (P < 0.001). PD-L1 expression levels were significantly different from those determined using the International Association for the Study of Lung Cancer (IASLC) grading system (P < 0.001).

CONCLUSIONS

PD-L1 expression was significantly associated with radiological and pathological invasiveness and driver mutation status in subcentimeter pulmonary nodules. The significance of PD-L1 expression in the evolution of early-stage lung adenocarcinoma requires further investigation.

Prognostic significance of tumor microenvironment assessed by machine learning algorithm in surgically resected non-small cell lung cancer

BACKGROUND

A methodology to assess the immune microenvironment (IME) of non-small cell lung cancer (NSCLC) has not been established, and the prognostic impact of IME factors is not yet clear.

AIMS

This study aimed to assess the IME factors and evaluate their prognostic values.

METHODS AND RESULTS

We assessed CD8+ tumor-infiltrating lymphocyte (TIL) density, forkhead box protein P3+ (Foxp3+ ) TIL density, and programmed death receptor ligand-1 (PD-L1) tumor proportion score (TPS) using a machine-learning algorithm in whole-slide imaging (WSI). We dichotomized patients according to TIL density or TPS and compared their clinical outcomes. Between September 2014 and September 2015, 165 patients with NSCLC were enrolled in the study. We assessed IME factors in the epithelium, stroma, and their combination. An improvement in disease-free survival (DFS) was observed in the high CD8+ TIL density group in the epithelium, stroma, and the combination of both. Moreover, the group with high PD-L1 TPS in the epithelium showed better DFS than that with low PD-L1 TPS. In the multivariate analysis, the CD8+ TIL density in the combination of epithelium and stroma and PD-L1 TPS in the epithelium were independent prognostic factors (hazard ratio [HR] = 0.43; 95% confidence interval [CI] = 0.26-0.72; p = .001, HR = 0.49; 95% CI = 0.30-0.81; p = .005, respectively).

CONCLUSION

Our approach demonstrated that the IME factors are related to survival in patients with NSCLC. The quantitative assessment of IME factors enables to discriminate patients with high risk of recurrence, who can be the candidates for adjuvant therapy. Assessing the CD8+ TIL density in the combination of epithelium and stroma might be more useful than their individual assessment because it is a simple and time-saving analysis of TILs in WSI.

Localized Imaging of Programmed Death-Ligand 1 on Individual Tumor-Derived Extracellular Vesicles for Prediction of Immunotherapy Response

Programmed death-ligand 1 (PD-L1) on tumor-derived small extracellular vesicles (EVs) is a biomarker for prediction of the immunotherapy response. However, conventional bulk measurement can hardly analyze the expression of PD-L1 on individual tumor-derived EVs. Herein, a method for localized imaging of tumor-derived individual EVs PD-L1 (LITIE) is developed. In this assay, EVs in plasma were directly captured on a biochip. Then the liposome-mediated membrane fusion strategy was used to image miR-21 in EVs to discriminate miR-21-positive EVs from the whole EVs populations. Subsequently, the primer exchange reaction (PER) is applied to generate localized and amplified fluorescent signals for imaging PD-L1 on identified tumor-derived EVs. When applied in clinical sample tests, the LITIE assay could effectively distinguish breast cancer patients from healthy donors or patients with benign tumors. Interestingly, in a mice melanoma model, the LITIE assay showed the ability to predict immunotherapy response even before drug treatment. Thus, we think the strategy of measuring individual tumor-derived EVs PD-L1 could serve as an alternative way for screening clinical responders suitable for immunotherapy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Development and clinical validation of a microfluidic-based platform for CTC enrichment and downstream molecular analysis

Background

Although many CTC isolation and detection methods can provide information on cancer cell counts, downstream gene and protein analysis remain incomplete. Therefore, it is crucial to develop a technology that can provide comprehensive information on both the number and profile of CTC.

Methods

In this study, we developed a novel microfluidics-based CTC separation and enrichment platform that provided detailed information about CTC.

Results

This platform exhibits exceptional functionality, achieving high rates of CTC recovery (87.1%) and purification (∼4 log depletion of WBCs), as well as accurate detection (95.10%), providing intact and viable CTCs for downstream analysis. This platform enables successful separation and enrichment of CTCs from a 4 mL whole-blood sample within 15 minutes. Additionally, CTC subtypes, selected protein expression levels on the CTC surface, and target mutations in selected genes can be directly analyzed for clinical utility using immunofluorescence and real-time polymerase chain reaction, and the detected PD-L1 expression in CTCs is consistent with immunohistochemical assay results.

Conclusion

The microfluidic-based CTC enrichment platform and downstream molecular analysis together provide a possible alternative to tissue biopsy for precision cancer management, especially for patients whose tissue biopsies are unavailable.

Comparison of SP263 and 22C3 immunohistochemistry PD-L1 assays for clinical efficacy of adjuvant atezolizumab in non-small cell lung cancer: results from the randomized phase III IMpower010 trial

BACKGROUND

Tumor samples from the phase III IMpower010 study were used to compare two programmed death-ligand 1 (PD-L1) immunohistochemistry assays (VENTANA SP263 and Dako 22C3) for identification of PD-L1 patient subgroups (negative, positive, low, and high expression) and their predictive value for adjuvant atezolizumab compared with best supportive care (BSC) in resectable early-stage non-small cell lung cancer (NSCLC).

METHODS

PD-L1 expression was assessed by the SP263 assay, which measured the percentage of tumor cells with any membranous PD-L1 staining, and the 22C3 assay, which scored the percentage of viable tumor cells showing partial or complete membranous PD-L1 staining.

RESULTS

When examining the concordance at the PD-L1-positive threshold (SP263: tumor cell (TC)≥1%; 22C3: tumor proportion score (TPS)≥1%), the results were concordant between assays for 83% of the samples. Similarly, at the PD-L1-high cut-off (SP263: TC≥50%; 22C3: TPS≥50%), the results were concordant between assays for 92% of samples. The disease-free survival benefit of atezolizumab over BSC was comparable between assays for PD-L1-positive (TC≥1% by SP263: HR, 0.58 (95% CI: 0.40 to 0.85) vs TPS≥1% by 22C3: HR, 0.65 (95% CI: 0.45 to 0.95)) and PD-L1-high (TC≥50% by SP263: HR, 0.27 (95% CI: 0.14 to 0.53) vs TPS≥50% by 22C3: HR, 0.31 (95% CI: 0.16 to 0.60)) subgroups.

CONCLUSIONS

The SP263 and 22C3 assays showed high concordance and a comparable clinical predictive value of atezolizumab at validated PD-L1 thresholds, suggesting that both assays can identify patients with early-stage NSCLC most likely to experience benefit from adjuvant atezolizumab.

TRIAL REGISTRATION NUMBER

NCT02486718.

Digital spatial profiling of melanoma shows CD95 expression in immune cells is associated with resistance to immunotherapy

Although immune checkpoint inhibitor (ICI) therapy has dramatically improved outcome for metastatic melanoma patients, many patients do not benefit. Since adverse events may be severe, biomarkers for resistance would be valuable, especially in the adjuvant setting. We performed high-plex digital spatial profiling (DSP) using the NanoString GeoMx® on 53 pre-treatment specimens from ICI-treated metastatic melanoma cases. We interrogated 77 targets simultaneously in four molecular compartments defined by S100B for tumor, CD68 for macrophages, CD45 for leukocytes, and nonimmune stromal cells defined as regions negative for all three compartment markers but positive for SYTO 13. For DSP validation, we confirmed the results obtained for some immune markers, such as CD8, CD4, CD20, CD68, CD45, and PD-L1, by quantitative immunofluorescence (QIF). In the univariable analysis, 38 variables were associated with outcome, 14 of which remained significant after multivariable adjustment. Among them, CD95 was further validated using multiplex immunofluorescence in the Discovery immunotherapy (ITX) Cohort and an independent validation cohort with similar characteristics, showing an association between high levels of CD95 and shorter progression-free survival. We found that CD95 in stroma was associated with resistance to ICI. With further validation, this biomarker could have value to select patients that will not benefit from immunotherapy.

Update in Immunotherapy for Advanced Non-Small Cell Lung Cancer: Optimizing Treatment Sequencing and Identifying the Best Choices

The introduction of immunotherapy has brought about a paradigm shift in the management of advanced non-small cell lung cancer (NSCLC). It has not only significantly improved the prognosis of patients but has also become a cornerstone of treatment, particularly in those without oncogenic driver mutations. Immune checkpoint inhibitors (ICIs) play a crucial role in the treatment of lung cancer and can be classified into two main groups: Anti-cytotoxic T lymphocyte antigen-4 (Anti-CTLA-4) and anti-T-cell receptor programmed cell death-1 or its ligand (Anti-PD-1 and Anti-PD-L1). Certainly, the landscape of approved first line immunotherapeutic approaches has expanded to encompass monotherapy, immunotherapy-exclusive protocols, and combinations with chemotherapy. The complexity of decision-making in this realm arises due to the absence of direct prospective comparisons. However, a thorough analysis of the long-term efficacy and safety data derived from pivotal clinical trials can offer valuable insights into optimizing treatment for different patient subsets. Moreover, ongoing research is investigating emerging biomarkers and innovative therapeutic strategies that could potentially refine the current treatment approach even further. In this comprehensive review, our aim is to highlight the latest advances in immunotherapy for advanced NSCLC, including the mechanisms of action, efficacy, safety profiles, and clinical significance of ICI.

Prognostic implication of PD-L1 in early-stage non-small cell lung cancer: a retrospective single-centre study

BACKGROUND

The prognostic role of programmed death-ligand 1 (PD-L1) expression in patients with localised and locally advanced non-small cell lung cancer has not been fully elucidated. This information could help to better interpret recent and upcoming results of phase III adjuvant or neoadjuvant anti-PD-1/PD-L1 immunotherapy studies.

METHODS

In a cohort of 146 patients with early or locally advanced non-small cell lung cancer treated with curative intent (by surgery or radiotherapy), we investigated the prognostic value of PD-L1 expression and its correlation with other biological and clinical features. PD-L1 expression was stratified by quartiles. Primary endpoints were overall and disease-free survival. We also analysed the prognostic impact of the presence of actionable mutations, implemented treatment modality and completion of the treatment plan. Neither type of patient received neoadjuvant or adjuvant immunotherapy or target therapy.

RESULTS

Of the 146 selected patients, 32 (21.9%) presented disease progression and 15 died (10.3%) at a median follow-up of 20 months. In a univariable analysis, PD-L1 expression ≥25% was associated with significantly lower disease-free survival (hazard ratio [HR]) 1.9, 95% confidence interval [CI] 1.0-3.9, p = 0.049). PD-L1 expression ≥50% did not lead to disease-free survival or overall survival benefits (HR 1.2 and 1.1, respectively; 95% CI 0.6-2.6 and 0.3-3.4, respectively; pnot significant). In a multivariate analysis, a stage >I (HR 2.7, 95% CI 1.2-6, p = 0.012) and having an inoperable tumour (HR 3.2, 95% CI 1.4-7.4, p = 0.005) were associated with lower disease-free survival.

CONCLUSION

The population of patients with early-stage non-small cell lung cancer and PD-L1 expression ≥25% who were treated with curative intent during the pre-immunotherapy era exhibited a worse prognosis. This finding provides justification for the utilisation of adjuvant immunotherapy in this subgroup of patients, based on the current evidence derived from disease-free survival outcomes. However, for patients with PD-L1 expression <25%, opting to wait for the availability of the overall survival results may be a prudent choice.

Monocyte subsets associated with the efficacy of anti‑PD‑1 antibody monotherapy

Immune checkpoint inhibitors (ICIs) are among the most notable advances in cancer immunotherapy; however, reliable biomarkers for the efficacy of ICIs are yet to be reported. Programmed death (PD)-ligand 1 (L1)-expressing CD14+ monocytes are associated with shorter overall survival (OS) time in patients with cancer treated with anti-PD-1 antibodies. The present study focused on the classification of monocytes into three subsets: Classical, intermediate and non-classical. A total of 44 patients with different types of cancer treated with anti-PD-1 monotherapy (pembrolizumab or nivolumab) were enrolled in the present study. The percentage of each monocyte subset was investigated, and the percentage of cells expressing PD-L1 or PD-1 within each of the three subsets was further analyzed. Higher pretreatment classical monocyte percentages were correlated with shorter OS (r=-0.32; P=0.032), whereas higher non-classical monocyte percentages were correlated with a favorable OS (r=0.39; P=0.0083). PD-L1-expressing classical monocytes accounted for a higher percentage of the total monocytes than non-classical monocytes with PD-L1 expression. In patients with non-small cell lung cancer (NSCLC), a higher percentage of PD-L1-expressing classical monocytes was correlated with shorter OS (r=-0.60; P=0.012), which is similar to the observation for the whole patient cohort. Comparatively, higher percentages of non-classical monocytes expressing PD-L1 were significantly associated with better OS, especially in patients with NSCLC (r=0.60; P=0.010). Moreover, a higher percentage of non-classical monocytes contributed to prolonged progression-free survival in patients with NSCLC (r=0.50; P=0.042), with similar results for PD-L1-expressing non-classical monocytes. The results suggested that the percentage of monocyte subsets in patients with cancer before anti-PD-1 monotherapy may predict the treatment efficacy and prognosis. Furthermore, more classical monocytes and fewer non-classical monocytes, especially those expressing PD-L1, are involved in shortening OS time, which may indicate the poor efficiency of anti-PD-1 treatment approaches.

Rapid determination of the presence of EGFR mutations with DNA-based nanocalipers

Selecting 1st-line treatment for lung cancer is currently a binary choice, either chemotherapy or targeted medicine, depending on whether EGFR mutations exist. Next-generation sequencing is fully capable of accurately identifying EGFR mutations and guiding the usage of tyrosine kinase inhibitors, but it is highly expensive. Moreover, as the sequencing is not helpful for patients with wild-type EGFR, the long wait for sequencing may delay the chemotherapy and correspondingly increase the risks of cancer progression. To address this issue, a new method for rapidly determining the presence of EGFR mutations is developed in this study. A series of DNA origami-engineered nanocalipers are designed and constructed to determine the EGFR spatial distribution of either mutated EGFR or wild-type EGFR lung cancer cells. The experimental results on cancer cell lines and 9 clinical tissue samples show that compared with wild-type EGFR cells, mutated EGFR cells have narrower EGFR spacing. Hence, the DNA nanocalipers are demonstrated to be capable of determining the presence of EGFR mutations and shrinking the detection period from weeks to hours, compared with sequencing. For determining EGFR mutation status in 9 clinical samples, DNA nanocalipers show 100% consistency with next-generation sequencing.

Multidimensional immune profiling in Gastric Cancer Multiplex Immunohistochemistry Atlas from Peking University Cancer Hospital project informs PD-1/PD-L1 blockade efficacy

BACKGROUND

Immunotherapy has resulted in impressive objective response rates and durable tumour remission, but only in a subset of gastric cancer (GC) patients. The PD-L1 combined positive score is the most widely used tissue-based biomarker for anti-PD-1/PD-L1 therapy; however, this unidimensional method has limitations. Next-generation exploration of tissue-based biomarkers for GC requires characterisation of various cellular markers and key immunoregulatory molecule expression in situ. Thus, a complete, stepwise solution covering the entire process from staining samples to cross-site utilisation of pathomics data is urgently needed.

METHODS

With the advanced multispectral imaging analysis method, web-based data repository, and interactive sharing technology, we conducted a project entitled Gastric Cancer Multiplex Immunohistochemistry Atlas from Peking University Cancer Hospital (GMAP). We propose a standard pipeline covering sample collection, staining, scanning multispectral images, constructing a spectral library, identifying and phenotyping cells, positioning each element, and quantitatively extracting immune features. We designed an open-access relational database to explore tissue-based biomarkers to determine PD-1/PD-L1 blockade efficacy.

RESULTS

The GMAP project detected the functional status and spatial location of more than 50 million cells using 15 markers in 80 GC patients, based on which billions of cell pairs were recognised, highlighting the rich spatial arrangement information and the fine tumour microenvironment structure. We generated a tumour-immune atlas using the count and spatial features of 65 immune cell types. We eventually selected the indicators and built a comprehensive risk-scoring system. Patients with higher risk score showed superior immunotherapy-related progression-free survival (irPFS) (hazard ratio [HR]: 3.19; P < 0.001; median irPFS: 4.87 versus 19.87months, respectively) and immunotherapy-related overall survival (HR: 3.10; P = 0.001; median irPFS: 10.03 versus 24.87months, respectively) compared with lower risk patients, demonstrating their potential for guiding anti-PD-1/PD-L1-based immunotherapy. Importantly, an easy-to-use and versatile web server was built to promote tissue-based biomarker exploration in GC.

CONCLUSION

The GMAP project highlighted the clinical value of tissue-based immune features as biomarkers for immunotherapeutic decision-making. We present a well-designed, detailed workflow for the orderly generation and use of a high-quality, spatially resolved pathological database.

Immune Biomarkers in Triple-Negative Breast Cancer: Improving the Predictivity of Current Testing Methods

Triple-negative breast cancer (TNBC) poses a significant challenge in terms of prognosis and disease recurrence. The limited treatment options and the development of resistance to chemotherapy make it particularly difficult to manage these patients. However, recent research has been shifting its focus towards biomarker-based approaches for TNBC, with a particular emphasis on the tumor immune landscape. Immune biomarkers in TNBC are now a subject of great interest due to the presence of tumor-infiltrating lymphocytes (TILs) in these tumors. This characteristic often coincides with the presence of PD-L1 expression on both neoplastic cells and immune cells within the tumor microenvironment. Furthermore, a subset of TNBC harbor mismatch repair deficient (dMMR) TNBC, which is frequently accompanied by microsatellite instability (MSI). All of these immune biomarkers hold actionable potential for guiding patient selection in immunotherapy. To fully capitalize on these opportunities, the identification of additional or complementary biomarkers and the implementation of highly customized testing strategies are of paramount importance in TNBC. In this regard, this article aims to provide an overview of the current state of the art in immune-related biomarkers for TNBC. Specifically, it focuses on the various testing methodologies available and sheds light on the immediate future perspectives for patient selection. By delving into the advancements made in understanding the immune landscape of TNBC, this study aims to contribute to the growing body of knowledge in the field. The ultimate goal is to pave the way for the development of more personalized testing strategies, ultimately improving outcomes for TNBC patients.

Common driver mutations and programmed death-ligand 1 expression in advanced non-small cell lung cancer in smokers and never smokers

BACKGROUND

In non-small cell lung cancer (NSCLC), there may be a relationship between programmed death-ligand 1 (PD-L1) expression, driver mutations and cigarette smoking.

METHODS

In this single-center retrospective study, the relationship between common driver mutations (EGFR mutation and ALK rearrangement) and PD-L1 expression in advanced NSCLC according to the patients' smoking history was examined. Light, moderate and heavy smokers had smoked < 20, 20-39, and ≥ 40 pack-years, respectively. The level of PD-L1 expression, assessed using Ventana SP263 monoclonal antibody assay, was defined by the tumor proportion score (TPS) as high expression (TPS ≥ 50%), low expression (TPS 1%-49%) and no expression (TPS < 1%).

RESULTS

101 (52.9%) of 191 advanced NSCLC patients were never smokers. EGFR mutations were more common in never smokers (64.4%) than in smokers (17.8%) with advanced NSCLC (P < 0.0001). A higher proportion of smokers (26.7%) had high PD-L1 expression compared to never smokers (13.9%) (P = 0.042). There was a trend for a higher proportion of male NSCLC patients [28 of 115 (24.3%)] than female patients [10 of 76 (13.2%)] to have high PD-L1 expression (P = 0.087]. High PD-L1 expression was seen in 32 of 110 (29.1%) patients with EGFR wild-type NSCLC but only in 6 of 81 (7.4%) patients with EGFR-mutant tumors (P < 0.0001). Among the 90 smokers with NSCLC, a higher proportion of heavy smokers (35.8%) than non-heavy smokers (13.5%) had high PD-L1 expression (P = 0.034). In patients with adenocarcinoma, high PD-L1 expression was seen in 25 of 77 (32.5%) patients with EGFR wild-type tumors but only in 4 of 70 (5.7%) patients with EGFR-mutant tumors (P < 0.0001). Among patients with adenocarcinoma, a significantly higher proportion of ever smokers (29.3%) than never smokers (13.5%) had high PD-L1 expression (P = 0.032). Among smokers with adenocarcinoma, a significantly higher proportion of heavy smokers (44.1%) than non-heavy smokers (8.3%) had high PD-L1 expression (P = 0.004). On multivariate analysis, after adjusting for gender and smoking status, heavy smoking and EGFR wild-type tumors remained significantly associated with high PD-L1 expression in NSCLCs and also in adenocarcinoma.

CONCLUSIONS

Heavy smoking and EGFR wild-type tumors were significantly associated with high PD-L1 expression in NSCLCs and also in adenocarcinoma.

Multiplex Immunohistochemistry and Immunofluorescence: A Practical Update for Pathologists

Our understanding of the biology and management of human disease has undergone a remarkable evolution in recent decades. Improved understanding of the roles of complex immune populations in the tumor microenvironment has advanced our knowledge of antitumor immunity, and immunotherapy has radically improved outcomes for many advanced cancers. Digital pathology has unlocked new possibilities for the assessment and discovery of the tumor microenvironment, such as quantitative and spatial image analysis. Despite these advances, tissue-based evaluations for diagnosis and prognosis continue to rely on traditional practices, such as hematoxylin and eosin staining, supplemented by the assessment of single biomarkers largely using chromogenic immunohistochemistry (IHC). Such approaches are poorly suited to complex quantitative analyses and the simultaneous evaluation of multiple biomarkers. Thus, multiplex staining techniques have significant potential to improve diagnostic practice and immuno-oncology research. The different approaches to achieve multiplexed IHC and immunofluorescence are described in this study. Alternatives to multiplex immunofluorescence/IHC include epitope-based tissue mass spectrometry and digital spatial profiling (DSP), which require specialized platforms not available to most clinical laboratories. Virtual multiplexing, which involves digitally coregistering singleplex IHC stains performed on serial sections, is another alternative to multiplex staining. Regardless of the approach, analysis of multiplexed stains sequentially or simultaneously will benefit from standardized protocols and digital pathology workflows. Although this is a complex and rapidly advancing field, multiplex staining is now technically feasible for most clinical laboratories and may soon be leveraged for routine diagnostic use. This review provides an update on the current state of the art for tissue multiplexing, including the capabilities and limitations of different techniques, with an emphasis on potential relevance to clinical diagnostic practice.

Validation of Immunotherapy Response Score as Predictive of Pan-solid Tumor Anti-PD-1/PD-L1 Benefit

Immunotherapy response score (IRS) integrates tumor mutation burden (TMB) and quantitative expression biomarkers to predict anti-PD-1/PD-L1 [PD-(L)1] monotherapy benefit. Here, we evaluated IRS in additional cohorts. Patients from an observational trial (NCT03061305) treated with anti-PD-(L)1 monotherapy were included and assigned to IRS-High (-H) versus -Low (-L) groups. Associations with real-world progression-free survival (rwPFS) and overall survival (OS) were determined by Cox proportional hazards (CPH) modeling. Those with available PD-L1 IHC treated with anti-PD-(L)1 with or without chemotherapy were separately assessed. Patients treated with PD-(L)1 and/or chemotherapy (five relevant tumor types) were assigned to three IRS groups [IRS-L divided into IRS-Ultra-Low (-UL) and Intermediate-Low (-IL), and similarly assessed]. In the 352 patient anti-PD-(L)1 monotherapy validation cohort (31 tumor types), IRS-H versus IRS-L patients had significantly longer rwPFS and OS. IRS significantly improved CPH associations with rwPFS and OS beyond microsatellite instability (MSI)/TMB alone. In a 189 patient (10 tumor types) PD-L1 IHC comparison cohort, IRS, but not PD-L1 IHC nor TMB, was significantly associated with anti-PD-L1 rwPFS. In a 1,103-patient cohort (from five relevant tumor types), rwPFS did not significantly differ in IRS-UL patients treated with chemotherapy versus chemotherapy plus anti-PD-(L)1, nor in IRS-H patients treated with anti-PD-(L)1 versus anti-PD-(L)1 + chemotherapy. IRS associations were consistent across subgroups, including both Europeans and non-Europeans. These results confirm the utility of IRS utility for predicting pan-solid tumor PD-(L)1 monotherapy benefit beyond available biomarkers and demonstrate utility for informing on anti-PD-(L)1 and/or chemotherapy treatment.

Significance

This study confirms the utility of the integrative IRS biomarker for predicting anti-PD-L1/PD-1 benefit. IRS significantly improved upon currently available biomarkers, including PD-L1 IHC, TMB, and MSI status. Additional utility for informing on chemotherapy, anti-PD-L1/PD-1, and anti-PD-L1/PD-1 plus chemotherapy treatments decisions is shown.

Tissue Age Affects Antigenicity and Scoring for the 22C3 Immunohistochemistry Companion Diagnostic Test

Programmed death-ligand 1 (PD-L1) antibody 22C3 is the approved companion diagnostic immunohistochemistry test for treatment with pembrolizumab and cemiplimab in multiple cancer types. The 22C3 and 28-8 antibodies target the extracellular domain (ECD) of PD-L1, which is known to contain N-glycosylation sites. We hypothesize that antigenicity could be affected by the degradation of the glycan part of the epitope and thus change the scoring of the assay over time. Here, we test samples over time and assess the effects of time and deglycosylation on PD-L1 signal by comparing an antibody with an ECD antigen to an antibody with an intracellular domain (ICD) antigen. Ten whole-tissue sections of non-small-cell lung cancer (NSCLC) from 2018 were selected for testing. Fresh-cut serial sections for each case were stained on DAKO Link48 for 22C3 according to the label. In parallel, a previously described laboratory-developed test using E1L3N (an ICD antibody) was performed on the Leica BondRX. Tumor proportion scores for 22C3 and E1L3N were read by a pathologist and compared to the previous clinical diagnoses. To determine the effect using a quantitative approach, a tissue microarray (TMA) cohort with 90 NSCLC cases was similarly assessed. Finally, to determine whether the possible effect of epitope glycosylation, antibodies were tested before and after enzymatic deglycosylation of specimens. We found that 6 of 7 archival positive samples showed a significant reduction in positive staining with 22C3 compared to the original diagnostic sample assessed 3 years earlier. In an older archival TMA cohort, a quantitative significant difference in signal intensity was noted when staining with 22C3 was compared to E1L3N. This loss of signal was not noted in the fresh cell line TMA consistent with a time-dependent degradation of staining. Finally, quantitative assessment of the fresh TMA showed a significant loss of signal after a deglycosylation procedure when stained with 22C3, which was not seen when stained with E1L3N. We believe that these data show that the glycan part of the 22C3 epitope is not stable over time, and that this issue should be considered when assessing archival tissue for diagnostic or research purposes.

PD-L1 expression downregulation by RNF43 in gastric carcinoma enhances antitumour activity of T cells

Ring finger protein 43 (RNF43), a transmembrane E3 ubiquitin ligase, has been indicated to be a potential biomarker for gastric cancer treatment, as this protein increases tumour cell apoptosis and suppresses cellular proliferation. The role of RNF43 in cellular immunotherapy remains unclear. Herein, we aimed to explore the expression level of RNF43 in gastric cancer cell lines and its role in cellular immunotherapy. The expression level of RNF43 and PD-L1 and their correlation in gastric cancer cell lines were analysed. The expression of PD-L1 was negatively correlated with that of RNF43 in gastric cancer cell lines. RNF43 interacted with PD-L1 to augment both K48- and K63-linked ubiquitination of PD-L1 in gastric cancer cell lines. In addition, RNF43 expression in gastric cancer cell lines could enhance the antitumour activity of T cells. In conclusion, this study reveals that RNF43 can inhibit PD-L1 expression to enhance the antitumour activity of cellular immunotherapy.

Combination of AFP vaccine and immune checkpoint inhibitors slows hepatocellular carcinoma progression in preclinical models

Many patients with hepatocellular carcinoma (HCC) do not respond to the first-line immune checkpoint inhibitor treatment. Immunization with effective cancer vaccines is an attractive alternative approach to immunotherapy. However, its efficacy remains insufficiently evaluated in preclinical studies. Here, we investigated HCC-associated self/tumor antigen, α-fetoprotein-based (AFP-based) vaccine immunization for treating AFP (+) HCC mouse models. We found that AFP immunization effectively induced AFP-specific CD8+ T cells in vivo. However, these CD8+ T cells expressed exhaustion markers, including PD1, LAG3, and Tim3. Furthermore, the AFP vaccine effectively prevented c-MYC/Mcl1 HCC initiation when administered before tumor formation, while it was ineffective against full-blown c-MYC/Mcl1 tumors. Similarly, anti-PD1 and anti-PD-L1 monotherapy showed no efficacy in this murine HCC model. In striking contrast, AFP immunization combined with anti-PD-L1 treatment triggered significant inhibition of HCC progression in most liver tumor nodules, while in combination with anti-PD1, it induced slower tumor progression. Mechanistically, we demonstrated that HCC-intrinsic PD-L1 expression was the primary target of anti-PD-L1 in this combination therapy. Notably, the combination therapy had a similar therapeutic effect in the cMet/β-catenin mouse HCC model. These findings suggest that combining the AFP vaccine and immune checkpoint inhibitors may be effective for AFP (+) HCC treatment.

The current advances and future directions of PD-1/PD-L1 blockade in head and neck squamous cell carcinoma (HNSCC) in the era of immunotherapy

Immune checkpoint inhibitors (ICIs) have previously demonstrated their efficacy and safety in various solid tumors, and with the growing interest in the application of ICIs in head and neck squamous cell carcinoma (HNSCC), various data have been reported. Mechanistically, HNSCC cells express programmed death ligand 1 (PD-L1), which binds to its receptor programmed death 1 (PD-1). Immune escape plays a key role in disease initiation and progression. Studying the abnormal activation of related pathways of PD-1/PD-L1 will help to understand the way of immunotherapy and find the advantageous population of immunotherapy. How to reduce HNSCC-related mortality and morbidity in this process has promoted the search for new therapeutic strategies, especially in the era of immunotherapy. PD-1 inhibitors have demonstrated significant prolongation of survival in recurrent/metastatic (R/M) HNSCC with a favorable safety profile. It also holds great promise in locally advanced (LA) HNSCC, where numerous studies are underway. Although immunotherapy has made great progress in HNSCC research, there are still many challenges. Therefore, in the review, we conducted an in-depth study on the expression of PD-L1 and the regulatory, immunosuppressive mechanisms caused by PD-L1, especially in head and neck squamous cell carcinoma, which is different from other tumors. And further summarize the situation, challenges and development trends of PD-1 and PD-L1 blockade in clinical practice.

Role of Surgical Pathologist for Detection of Predictive Immuno-oncological Factors in Breast Cancer

Immune checkpoint inhibitors (ICIs) have changed therapy strategies in breast cancer (BC) patients suffering from triple-negative breast cancer (TNBC). For example, in Europe the anti-programmed cell death 1 ligand 1 (PD-L1) ICI Azetolizumab is approved for adult patients with locally advanced or metastasized TNBC (mTNBC), depending on the immunohistochemical (IHC) PD-L1 expression of immune cells in the tumor area [immune cell (IC) score ≥1%); the anti-programmed cell death 1 (PD-1) ICI pembrolizumab is approved for mTNBC if PD-L1 Combined Positive Score (CPS), that is PD-L1 expression on tumor and/or immune cells, is ≥10. For early TNBC, in contrast, neoadjuvant use of pembrolizumab is approved in the United States and Europe independent from PD-L1 IHC expression. The determination of PD-L1 expression in tumor tissue to predict response to ICI therapy requires sensitive immunostaining with appropriate primary antibodies and staining protocols and a standardized and meticulous assessment of PD-L1 IHC stained breast cancer tissue slides. For the selection of the test material and continuous quality control of the dyeing, high standards must be applied. The evaluation is carried out according to various evaluation algorithms (scores). Here, the role of PD-L1 in BC and the currently most relevant PD-L1 assays and scores for TNBC will be explained. Furthermore, other tissue-based biomarkers potentially predictive for ICI therapy response in BC, for example, tumor mutational burden (TMB), will be presented in this review.

Disease-free Survival Analysis for Patients with High-risk Muscle-invasive Urothelial Carcinoma from the Randomized CheckMate 274 Trial by PD-L1 Combined Positive Score and Tumor Cell Score

BACKGROUND

The CheckMate 274 trial demonstrated improved disease-free survival (DFS) with adjuvant nivolumab versus placebo in patients with muscle-invasive urothelial carcinoma at high risk of recurrence after radical surgery in both the intent-to-treat population and the subset with tumor programmed death ligand 1 (PD-L1) expression ≥1%.

OBJECTIVE

To analyze DFS by combined positive score (CPS), which is based on PD-L1 expression in both tumor and immune cells.

DESIGN, SETTING, AND PARTICIPANTS

We randomized a total of 709 patients 1:1 to nivolumab 240 mg or placebo every 2 wk intravenously for ≤1 yr of adjuvant treatment.

INTERVENTION

Nivolumab 240 mg.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Primary endpoints were DFS in the intent-to-treat population and patients with tumor PD-L1 expression ≥1% using the tumor cell (TC) score. CPS was determined retrospectively from previously stained slides. Tumor samples with both quantifiable CPS and TC were analyzed.

RESULTS AND LIMITATIONS

Of 629 patients evaluable for CPS and TC, 557 (89%) had CPS ≥1, 72 (11%) had CPS <1, 249 (40%) had TC ≥1%, and 380 (60%) had TC <1%. Among patients with TC <1%, 81% (n = 309) had CPS ≥1. DFS was improved with nivolumab versus placebo for patients with TC ≥1% (hazard ratio [HR] 0.50, 95% confidence interval [CI] 0.35-0.71), those with CPS ≥1 (HR 0.62, 95% CI 0.49-0.78), and patients with both TC <1% and CPS ≥1 (HR 0.73, 95% CI 0.54-0.99).

CONCLUSION

More patients had CPS ≥1 than TC ≥1%, and most patients who had TC <1% had CPS ≥1. In addition, patients with CPS ≥1 experienced improved DFS with nivolumab. These results may, in part, explain the mechanisms underlying a benefit with adjuvant nivolumab even in patients who had both TC <1% and CPS ≥1.

PATIENT SUMMARY

We studied survival time without cancer recurrence (disease-free survival; DFS) for patients treated with nivolumab versus placebo after surgery to remove the bladder or components of the urinary tract for bladder cancer in the CheckMate 274 trial. We assessed the impact of levels of the protein PD-L1 expressed either on tumor cells (tumor cell score; TC) or on both tumor cells and immune cells surrounding the tumor (combined positive score; CPS). DFS was impoved with nivolumab versus placebo for patients with TC ≥1%, CPS ≥1, and for patients with both TC <1% and CPS ≥1. This analysis may help physicians understand which patients would benefit most from treatment with nivolumab.

Clinicopathologic features, tumor immune microenvironment and genomic landscape of EBV-related and EBV-unrelated poorly differentiated nonkeratinizing squamous cell carcinoma of the thymus

OBJECTIVES

Knowledge regarding thymic EBV-related poorly differentiated nonkeratinizing squamous cell carcinoma (PDNKSCC), also known as lymphoepithelial carcinoma (LEC), is extremely limited due to its rarity.

MATERIALS AND METHODS

This multi-institutional study enrolled 85 patients with thymic PDNKSCC. DNA in situ hybridization was performed to evaluate the EBV status of all 85 cases. Immunohistochemistry and next generation sequencing were performed to compare the differences in the clinicopathological and molecular features between EBV-related and EBV-unrelated PDNKSCC. Tumor-infiltrating lymphocytes (TILs) were also analyzed by these methods.

RESULTS

The 85 cases were classified into 27 EBV-related PDNKSCCs (31.8 %) and 58 EBV-unrelated PDNKSCCs (68.2 %) according to the EBV status, and 35 Lymphoepithelioma pattern (LP) (41.2 %) and 50 desmoplastic pattern (DP) (58.8 %) according to the histological characteristics. Compared to the EBV-unrelated PDNKSCC, EBV-related PDNKSCC showed a younger patient predominance and more commonly displayed a LP subtype. Additionally, LP-type cases were divided into two groups: Group 1 (EBV-related, 20/85) and Group 2 (EBV-unrelated, 15/85); the DP-type cases were divided into Group 3 (EBV-unrelated, 43/85) and Group 4 (EBV-related, 7/85). The four Groups showed a significant association with patients' OS and PFS. EBV-related PDNKSCC had significantly higher PD-L1 + tumor cells (TCs) and PD-L1 + and CD8 + immune cells (ICs) than EBV-unrelated PDNKSCC. The tumor microenvironment immune type (TMIT) I (PDL1-Tumor+/CD8-High) was more common in EBV-related PDNKSCC, especially in Group 1(LP and EBV related) with more than 90 % cases belonged to TMIT I. Molecular analysis demonstrated that EBV-related PDNKSCC had a significantly higher tumour mutational burden and frequency of somatic mutations than EBV-unrelated cases.

CONCLUSIONS

EBV-related PDNKSCC, especially the Group 1, could be a candidate for immunotherapy and EBV positivity may provide an indication for the selection of targeted therapy due to their high tumour mutational burden.

Precision Medicine in Bladder Cancer: Present Challenges and Future Directions

Bladder cancer (BC) is characterized by significant histopathologic and molecular heterogeneity. The discovery of molecular pathways and knowledge of cellular mechanisms have grown exponentially and may allow for better disease classification, prognostication, and development of novel and more efficacious noninvasive detection and surveillance strategies, as well as selection of therapeutic targets, which can be used in BC, particularly in a neoadjuvant or adjuvant setting. This article outlines recent advances in the molecular pathology of BC with a better understanding and deeper focus on the development and deployment of promising biomarkers and therapeutic avenues that may soon make a transition into the domain of precision medicine and clinical management for patients with BC.

Using chitosan-stabilized, hyaluronic acid-modified selenium nanoparticles to deliver CD44-targeted PLK1 siRNAs for treating bladder cancer

Aims: Achieving an effective biocompatible system for siRNAs delivery to the tumor site remains a significant challenge. Materials & methods: Selenium nanoparticles (SeNPs) modified by chitosan (CS) and hyaluronic acid (HA) were fabricated for PLK1 siRNAs (siPLK1) delivery to the bladder cancer cells. The HA-CS-SeNP@siPLK1 efficacy was evaluated using in vitro and in vivo models. Results: HA-CS-SeNP@siPLK1 was selectively internalized into T24 cells through clathrin-mediated endocytosis. Treatment with HA-CS-SeNP@siPLK1 successfully silenced the PLK1 gene, inhibited cell proliferation and induced cell cycle arrest in vitro. HA-CS-SeNP@siPLK1 could also inhibit tumor growth in vivo without causing systemic toxicity. Conclusion: Our results suggest that HA-CS-SeNPs may provide a good vehicle for delivering siPLK1 to the bladder tumor site.

[New update to the guidelines on testing predictive biomarkers in non-small-cell lung cancer: a National Consensus of the Spanish Society of Pathology and the Spanish Society of Medical Oncology]

Non-small cell lung cancer (NSCLC) presents the greatest number of identified therapeutic targets, some of which have therapeutic utility. Currently, detecting EGFR, BRAF, KRAS and MET mutations, ALK, ROS1, NTRK and RET translocations, and PD-L1 expression in these patients is considered essential. The use of next-generation sequencing (NGS) facilitates precise molecular diagnosis and allows the detection of other emerging mutations, such as the HER2 mutation and predictive biomarkers for immunotherapy responses. In this consensus, a group of experts in the diagnosis and treatment of NSCLC selected by the Spanish Society of Pathology (SEAP) and the Spanish Society of Medical Oncology (SEOM) have evaluated currently available information and propose a series of recommendations to optimize the detection and use of biomarkers in daily clinical practice.

State of the Art of Pathologic and Molecular Testing

Advances in the treatment of non-small cell lung carcinoma have resulted in improved histologic classification and the implementation of molecular testing for predictive biomarkers into the routine diagnostic workflow. Over the past decade, molecular testing has evolved from single-gene assays to high-thoroughput comprehensive next-generation sequencing. Economic barriers, suboptimal turnaround time to obtain the results, and limited tissue available for molecular assays resulted in adoption of liquid biopsies (ctDNA) into clinical practice. Multiplex immunohistochemical/immunofluorescence assays evaluating tumor microenvironment together with the AI approaches are anticipated to translate from research into clinical care.

Clinical Benefit of First-Line Programmed Death-1 Antibody Plus Chemotherapy in Low Programmed Cell Death Ligand 1-Expressing Esophageal Squamous Cell Carcinoma: A Post Hoc Analysis of JUPITER-06 and Meta-Analysis

PURPOSE

Pembrolizumab or nivolumab plus chemotherapy was approved as a first-line treatment for high programmed cell death ligand 1 (PD-L1)-expressing esophageal squamous cell carcinoma (ESCC) by the European Medicines Agency, whereas the US Food and Drug Administration approved this regimen regardless of PD-L1 expression. The superiority of programmed death-1 (PD-1) antibody plus chemotherapy over chemotherapy alone in patients with low PD-L1-expressing ESCC remains debatable.

METHODS

Post hoc analysis of the Chinese JUPITER-06 study focusing on efficacy stratified by PD-L1 tumor proportion score (TPS; using JS311 antibody) was conducted. Electronic databases were searched to identify eligible randomized controlled trials for meta-analysis. Study-level pooled analyses of hazard ratios (HRs) for overall survival and progression-free survival and odds ratios for objective response rate according to PD-L1 expression were performed.

RESULTS

The post hoc analysis of JUPITER-06 showed more prominent clinical benefit with PD-1 antibody plus chemotherapy than with chemotherapy alone in both the high and low PD-L1-expressing subgroups. Five randomized controlled trials were included in the meta-analysis, and two PD-L1 expression scoring criteria, TPS (≥ 1%/< 1%) and combined positive score (CPS, ≥ 10/< 10), were analyzed. Significant overall survival benefit by adding PD-1 antibody to chemotherapy was observed in both the TPS < 1% (HR, 0.74; 95% CI, 0.56 to 0.97) and CPS < 10 (HR, 0.77; 95% CI, 0.66 to 0.89) subgroups. Similarly, significantly prolonged progression-free survival was observed in both the TPS < 1% (HR, 0.66; 95% CI, 0.50 to 0.86) and CPS < 10 (HR, 0.63; 95% CI, 0.47 to 0.84) subgroups. In addition, the objective response rate of the TPS < 1% subgroup was significantly improved (odds ratio, 1.71; 95% CI, 1.27 to 2.29). In all high PD-L1-expressing subgroups, the pooled benefit of PD-1 antibody plus chemotherapy was significantly better than that of chemotherapy.

CONCLUSION

This study provided novel evidence supporting the superiority of PD-1 antibody plus chemotherapy to chemotherapy alone in patients with advanced ESCC with low PD-L1 expression. Further studies of predictive biomarkers are warranted.

Safety of Nivolumab Added to Chemoradiation Therapy Platforms for Intermediate and High-Risk Locoregionally Advanced Head and Neck Squamous Cell Carcinoma: RTOG Foundation 3504

PURPOSE

Programmed death-1 immune checkpoint blockade improves survival of patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC), but the benefits of addition to (chemo)radiation for newly diagnosed patients with HNSCC remain unknown.

METHODS AND MATERIALS

We evaluated the safety of nivolumab concomitant with 70 Gy intensity modulated radiation therapy and weekly cisplatin (arm 1), every 3-week cisplatin (arm 2), cetuximab (arm 3), or alone for platinum-ineligible patients (arm 4) in newly diagnosed intermediate- or high-risk locoregionally advanced HNSCC. Patients received nivolumab from 2 weeks prior to radiation therapy until 3 months post-radiation therapy. The primary endpoint was dose-limiting toxicity (DLT). If ≤2 of the first 8 evaluable patients experienced a DLT, an arm was considered safe. Secondary endpoints included toxicity and feasibility of adjuvant nivolumab to 1 year, defined as all 7 additional doses received by ≥4 of the first 8 evaluable patients across arms.

RESULTS

Of 39 patients (10 in arms 1, 3, 4 and 9 in arm 2), 72% had T3-4 tumors, 85% had N2-3 nodal disease, and 67% had >10 pack-years of smoking. There were no DLTs in arms 1 and 2, 1 in arm 3 (mucositis), and 2 in arm 4 (lipase elevation and mucositis in 1 and fatigue in another). The most common grade ≥3 nivolumab-related adverse events were lipase increase, mucositis, diarrhea, lymphopenia, hyponatremia, leukopenia, fatigue, and serum amylase increase. Adjuvant nivolumab was feasible as defined in the protocol.

CONCLUSIONS

Concomitant nivolumab with the 4 tested regimens was safe for patients with intermediate- and high-risk HNSCC, and subsequent adjuvant nivolumab was feasible as defined (NCT02764593).

High Interobserver Variability among Pathologists Using Combined Positive Score to Evaluate PD-L1 Expression in Gastric, Gastroesophageal Junction and Esophageal Adenocarcinoma

Reliable, reproducible methods to interpret programmed death ligand-1 (PD-L1) expression on tumor cells (TC) and immune cells (IC) are needed for pathologists to inform decisions associated with checkpoint inhibitor therapies. Our international study compared interpathologist agreement of PD-L1 expression using combined positive score (CPS) under standardized conditions on samples from patients with gastric/gastroesophageal junction/esophageal adenocarcinoma. Tissue sections from 100 adenocarcinoma pre-treatment biopsies were stained in a single laboratory using the PD-L1 IHC 28-8 and 22C3(Agilent) pharmDx immunohistochemical assays. PD-L1 CPS was evaluated by 12 pathologists on scanned whole slide images of these biopsies before and after a 2-hour CPS training session by Agilent. Additionally, pathologists determined PD-L1 positive TC, IC, and total viable TC on a single tissue fragment from 35 of 100 biopsy samples. Scoring agreement among pathologists was assessed using the intraclass correlation coefficient (ICC). Interobserver variability for CPS for 100 biopsies was high with only fair agreement among pathologists both pre- (range 0.45 to 0.55) and post-training (range 0.56 to 0.57) for both assays. For the 35 single biopsy samples, poor/fair agreement was also observed for the total number viable TC (ICC 0.09), number of PD-L1 positive IC (ICC 0.19), number of PD-L1 positive TC (ICC 0.54), and calculated CPS (ICC 0.14), while calculated TC score (positive TC/Total TC) showed excellent agreement (ICC 0.82). Retrospective histologic review of samples with the poorest interpathologist agreement revealed (1) ambiguous identification of positively staining stromal cells, (2) faint or variable intensity of staining, (3) difficulty in distinguishing membranous from cytoplasmic tumor staining, and (4) cautery and crush artifact, as possible confounding factors. These results emphasize the need for objective techniques to standardize the interpretation of PD-L1 expression when using the CPS methodology on gastric/gastroesophageal junction cancer biopsies to accurately identify patients most likely to benefit from immune checkpoint inhibitor therapy.

TKIs in combination with immunotherapy for hepatocellular carcinoma

INTRODUCTION

The treatment landscape of hepatocellular carcinoma (HCC) has significantly changed over the last 5 years with multiple options in the frontline, second line, and beyond. Tyrosine kinase inhibitors (TKIs) were the first approved systemic treatments for the advanced stage of HCC; however, thanks to the increasing knowledge and characterization of the immunological features of the tumor microenvironment, the systemic treatment of HCC has been further expanded with the immune checkpoint inhibitor (ICI) approach and the following evidence of the higher efficacy obtained with combined treatment with atezolizumab plus bevacizumab over sorafenib.

AREAS COVERED

In this review, we look at rationale, efficacy, and safety profiles of current and emerging ICI/TKI combination treatments and discuss the available results from other clinical trials using similar combinatorial therapeutic approaches.

EXPERT OPINION

Angiogenesis and immune evasion are the two key pathogenic hallmarks of HCC. While the pioneering regimen of atezolizumab/bevacizumab is consolidating as the first-line treatment of advanced HCC, it will be essential, in the near future, to determine the best second-line treatment options and how to optimize the selection of the most effective therapies. These points still need to be addressed by future studies that are largely warranted to enhance the treatment's effectiveness and ultimately to tackle down HCC lethality.

Tissue- and liquid biopsy-based biomarkers for immunotherapy in breast cancer

Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy and now represent the mainstay of treatment for many tumor types, including triple-negative breast cancer and two agnostic registrations. However, despite impressive durable responses suggestive of an even curative potential in some cases, most patients receiving ICIs do not derive a substantial benefit, highlighting the need for more precise patient selection and stratification. The identification of predictive biomarkers of response to ICIs may play a pivotal role in optimizing the therapeutic use of such compounds. In this Review, we describe the current landscape of tissue and blood biomarkers that could serve as predictive factors for ICI treatment in breast cancer. The integration of these biomarkers in a "holistic" perspective aimed at developing comprehensive panels of multiple predictive factors will be a major step forward towards precision immune-oncology.

Baseline extracellular vesicle TGF-β is a predictive biomarker for response to immune checkpoint inhibitors and survival in non-small cell lung cancer

BACKGROUND

Immune-checkpoint inhibitors (ICIs) are an effective therapeutic strategy, improving the survival of patients with lung cancer compared with conventional treatments. However, novel predictive biomarkers are needed to stratify which patients derive clinical benefit because the currently used and highly heterogenic histological PD-L1 has shown low accuracy. Liquid biopsy is the analysis of biomarkers in body fluids and represents a minimally invasive tool that can be used to monitor tumor evolution and treatment effects, potentially reducing biases associated with tumor heterogeneity associated with tissue biopsies. In this context, cytokines, such as transforming growth factor-β (TGF-β), can be found free in circulation in the blood and packaged into extracellular vesicles (EVs), which have a specific delivery tropism and can affect in tumor/immune system interaction. TGF-β is an immunosuppressive cytokine that plays a crucial role in tumor immune escape, treatment resistance, and metastasis. Thus, we aimed to evaluate the predictive value of circulating and EV TGF-β in patients with non-small-cell lung cancer receiving ICIs.

METHODS

Plasma samples were collected in 33 patients with advanced non-small-cell lung cancer before and during treatment with ICIs. EV were isolated from plasma by serial ultracentrifugation methods and circulating and EV TGF-β expression levels were evaluated by enzyme-linked immunosorbent assay.

RESULTS

Baseline high expression of TGF-β in EVs was associated with nonresponse to ICIs as well as shorter progression-free survival and overall survival, outperforming circulating TGF-β levels and tissue PD-L1 as a predictive biomarker.

CONCLUSION

If validated, EV TGF-β could be used to improve patient stratification, increasing the effectiveness of treatment with ICIs and potentially informing combinatory treatments with TGF-β blockade.

PLAIN LANGUAGE SUMMARY

Treatment with immune-checkpoint inhibitors (ICIs) has improved the survival of some patients with lung cancer. However, the majority of patients do not benefit from this treatment, making it essential to develop more reliable biomarkers to identify patients most likely to benefit. In this pilot study, the expression of transforming growth factor-β (TGF-β) in blood circulation and in extracellular vesicles was analyzed. The levels of extracellular vesicle TGF-β before treatment were able to determine which patients would benefit from treatment with ICIs and have a longer survival with higher accuracy than circulating TGF-β and tissue PD-L1, which is the currently used biomarker in clinical practice.

Development and validation of an integrative pan-solid tumor predictor of PD-1/PD-L1 blockade benefit

BACKGROUND

Anti-PD-1 and PD-L1 (collectively PD-[L]1) therapies are approved for many advanced solid tumors. Biomarkers beyond PD-L1 immunohistochemistry, microsatellite instability, and tumor mutation burden (TMB) may improve benefit prediction.

METHODS

Using treatment data and genomic and transcriptomic tumor tissue profiling from an observational trial (NCT03061305), we developed Immunotherapy Response Score (IRS), a pan-tumor predictive model of PD-(L)1 benefit. IRS real-world progression free survival (rwPFS) and overall survival (OS) prediction was validated in an independent cohort of trial patients.

RESULTS

Here, by Cox modeling, we develop IRS-which combines TMB with CD274, PDCD1, ADAM12 and TOP2A quantitative expression-to predict pembrolizumab rwPFS (648 patients; 26 tumor types; IRS-High or -Low groups). In the 248 patient validation cohort (248 patients; 24 tumor types; non-pembrolizumab PD-[L]1 monotherapy treatment), median rwPFS and OS are significantly longer in IRS-High vs. IRS-Low patients (rwPFS adjusted hazard ratio [aHR] 0.52, p = 0.003; OS aHR 0.49, p = 0.005); TMB alone does not significantly predict PD-(L)1 rwPFS nor OS. In 146 patients treated with systemic therapy prior to pembrolizumab monotherapy, pembrolizumab rwPFS is only significantly longer than immediately preceding therapy rwPFS in IRS-High patients (interaction test p = 0.001). In propensity matched lung cancer patients treated with first-line pembrolizumab monotherapy or pembrolizumab+chemotherapy, monotherapy rwPFS is significantly shorter in IRS-Low patients, but is not significantly different in IRS-High patients. Across 24,463 molecularly-evaluable trial patients, 7.6% of patients outside of monotherapy PD-(L)1 approved tumor types are IRS-High/TMB-Low.

CONCLUSIONS

The validated, predictive, pan-tumor IRS model can expand PD-(L)1 monotherapy benefit outside currently approved indications.

Immunotherapeutic targets in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is one of the most common types of cancer in the world and has a 5-year survival rate of ~20%. Immunotherapies have shown promising results leading to durable responses, however, they are only effective for a subset of patients. To determine the best therapeutic approach, a thorough and in-depth profiling of the tumour microenvironment (TME) is required. The TME is a complex network of cell types that form an interconnected network, promoting tumour cell initiation, growth and dissemination. The stroma, immune cells and endothelial cells that comprise the TME generate a plethora of cytotoxic or cytoprotective signalling pathways. In this review, we discuss immunotherapeutic targets in NSCLC tumours and how the TME may influence patients' response to immunotherapy.

The Ring Study: an international comparison of PD-L1 diagnostic assays and their interpretation in non-small cell lung cancer, head and neck squamous cell cancer and urothelial cancer

PD-L1 immunohistochemistry has been approved as a diagnostic assay for immunotherapy. However, an international comparison across multiple cancers is lacking. This study aimed to assess the performance of PD-L1 diagnostic assays in non-small cell lung cancer (NSCLC), head and neck squamous cell cancer (HNSCC) and urothelial cancer (UC). The excisional specimens of NSCLC, HNSCC and UC were assayed by Ventana SP263 and scored at three sites in each country, including Australia, Brazil, Korea, Mexico, Russia and Taiwan. All slides were rotated to two other sites for interobserver scoring. The same cohort of NSCLC was assessed with Dako 22C3 pharmDx PD-L1 for comparison. The PD-L1 immunopositivity was scored according to the approved PD-L1 scoring algorithms which were the percentage of PD-L1-expressing tumour cell (TC) and tumour proportion score (TPS) by Ventana SP263 and Dako 22C3 staining, respectively. In NSCLC, the comparison demonstrated the comparability of the SP263 and 22C3 assays (cut-off of 1%, κ=0.71; 25%, κ=0.75; 50%, κ=0.81). The interobserver comparisons showed moderate to almost perfect agreement for SP263 in TC staining at 25% cut-off (NSCLC, κ=0.72 to 0.86; HNSCC, κ=0.60 to 0.82; UC, κ=0.68 to 0.91) and at 50% cut-off for NSCLC (κ=0.64 to 0.90). Regarding the immune cell (IC) scoring in UC, there was a lower correlation (concordance correlation coefficient=0.10 to 0.68) and poor to substantial agreements at the 1%, 5%, 10% and 25% cut-offs (κ= -0.04 to 0.76). The interchangeability of SP263 and 22C3 in NSCLC might be acceptable, especially at the 50% cut-off. In HNSCC, the performance of SP263 is comparable across five countries. In UC, there was low concordance of IC staining, which may affect treatment decisions. Overall, the study showed the reliability and reproducibility of SP263 in NSCLC, HNSCC and UC.