Comparative analysis of PD-L1 expression between primary and metastatic pulmonary adenocarcinomas

The roles of PD-L1 in the various stages of tumor metastasis

The interaction between tumor programmed death ligand 1 (PD-L1) and T-cell programmed cell death 1 (PD-1) has long been acknowledged as a mechanism for evading immune surveillance. Recent studies, however, have unveiled a more nuanced role of tumor-intrinsic PD-L1 in reprograming tumoral phenotypes. Preclinical models emphasize the synchronized effects of both intracellular and extracellular PD-L1 in promoting metastasis, with intricate interactions with the immune system. This review aims to summarize recent findings to elucidate the spatiotemporal heterogeneity of PD-L1 expression and the pro-metastatic roles of PD-L1 in the entire process of tumor metastasis. For example, PD-L1 regulates the epithelial-to-mesenchymal transition (EMT) process, facilitates the survival of circulating tumor cells, and induces the formation of immunosuppressive environments at pre-metastatic niches and metastatic sites. And the complexed and dynamic regulation process of PD-L1 for tumor metastasis is related to the spatiotemporal heterogeneity of PD-L1 expression and functions from tumor primary sites to various metastatic sites. This review extends the current understandings for the roles of PD-L1 in mediating tumor metastasis and provides new insights into therapeutic decisions in clinical practice.

Early-Stage Non-Small Cell Lung Cancer: Prevalence of Actionable Alterations in a Monocentric Consecutive Cohort

Early-stage (ES) non-small cell lung cancer (NSCLC) is diagnosed in about 30% of cases. The preferred treatment is surgery, but a significant proportion of patients experience recurrence. Neoadjuvant and adjuvant chemotherapy has a limited clinical benefit. EGFR tyrosine kinase inhibitors and immunotherapy have recently opened new therapeutic scenarios. However, only a few data are available about the ES-NSCLC molecular landscape and the impact of oncogene addiction on therapy definition. Here, we determined the prevalence of the main lung cancer driver alterations in a monocentric consecutive cohort. Molecular analysis was performed on 1122 cases, including 368 ES and 754 advanced NSCLC. The prevalence of actionable alterations was similar between early and advanced stages. ES-NSCLC was significantly enriched for MET exon-14 skipping alterations and presented a lower prevalence of BRAF p.(V600E) mutation. PD-L1 expression levels, evaluated according to actionable alterations, were higher in advanced than early tumors harboring EGFR, KRAS, MET alterations and gene fusions. Taken together, these results confirm the value of biomarker testing in ES-NSCLC. Although approved targeted therapies for ES-NSCLC are still limited, the identification of actionable alterations could improve patients' selection for immunotherapy, favoring the enrollment in clinical trials and allowing a faster treatment start at disease recurrence.

PD-L1 assessment in lung cancer biopsies-pitfalls and limitations

The programmed cell death-ligand 1 (PD-L1) protein expression on tumor cells predicts the efficacy of immunotherapy in patients with non-small cell lung cancer. However, the assessment of PD-L1 expression on tumor cells has limited power for selecting patients for immunotherapy due to intra-tumoral heterogeneity and inter-tumoral heterogeneity of PD-L1 expression, the inter-observer variability in scoring PD-L1 staining, and reproducibility. These difficulties and pitfalls in interpreting the PD-L1 assessment are discussed in detail in this review.

Redetermination of PD-L1 expression after chemio-radiation in locally advanced PDL1 negative NSCLC patients: retrospective multicentric analysis

Background

Chemoradiation therapy (CRT) is the treatment of choice for locally advanced non-small cell lung cancer (LA-NSCLC). Several clinical trials that combine programmed cell death 1 (PD1) axis inhibitors with radiotherapy are in development for patients with LA-NSCLC. However, the effect of CRT on tumor cells programmed cell death ligand-1 (PD-L1) expression is unknown.

Methods

In this multicentric retrospective study, we analyzed paired NSCLC specimens that had been obtained pre- and post-CRT. PD-L1 expression on tumor cells was studied by immunohistochemistry. The purpose of this study was to evaluate the feasibility, risk of complications, and clinical relevance of performing re-biopsy after CRT in patients with PD-L1 negative LA-NSCLC.

Results

Overall, 31 patients from 6 centers with PD-L1 negative LA-NSCLC were analyzed. The percentage of tumor cells with PD-L1 expression significantly increased between pre- and post-CRT specimens in 14 patients (45%). Nine patients had unchanged PD-L1 expression after CRT, in five patients the rebiopsy material was insufficient for PD-L1 analysis and in two patients no tumor cells at rebiopsy were found. The post-rebiopsy complication rate was very low (6%). All patients with positive PD-L1 re-biopsy received Durvalumab maintenance after CRT, except one patient who had a long hospitalization for tuberculosis reactivation. Median PFS of patients with unchanged or increased PD-L1 expression was 10 and 16.9 months, respectively.

Conclusion

CRT administration can induce PD-L1 expression in a considerable fraction of PD-L1 negative patients at baseline, allowing them receiving the maintenance Durvalumab in Europe. Hence, after a definitive CRT, PD-L1 redetermination should be considered in patients with LA-NSCLC PD-L1 negative, to have a better selection of maintenance Durvalumab candidates.

Prognostic value of KRAS mutations, TP53 mutations and PD-L1 expression among lung adenocarcinomas treated with immunotherapy

AIMS

The aim of this study was to investigate the association between oncogenic alterations and programmed cell death ligand 1 (PD-L1) expression in lung adenocarcinomas, as well as the prognostic value of KRAS and/or TP53 mutations in patients treated with immunotherapy.

METHODS

This study is a retrospective cohort study of 519 patients with lung adenocarcinomas analysed for mutations and PD-L1 expression. Data were collected from electronic pathology record system, next-generation sequencing system, and clinical databases. Association between mutations and PD-L1 expression was investigated, as well as survival statistics of the 65 patients treated with immunotherapy.

RESULTS

41% of the samples contained a KRAS mutation, predominantly together with mutations in TP53 (41%) or STK11 (10%). Higher expression of PD-L1 was seen among patients with KRAS mutations (p=0.002) and EGFR wild type (p=0.006). For patients treated with immunotherapy, there was no statistically significant difference for overall survival (OS) and progression-free survival (PFS) according to KRAS mutation status, TP53 mutation status or PD-L1 expression. The HR for concomitant mutations in TP53 and KRAS was 0.78 (95% CI 0.62 to 0.99) for OS and 0.43 (0.21 to 0.88) for PFS. Furthermore, concomitant TP53 and KRAS mutations predicted a better PFS (p=0.015) and OS (p=0.029) compared with no mutations or a single mutation in either TP53 or KRAS.

CONCLUSION

Mutations in TP53 together with KRAS may serve as a potential biomarker for survival benefits with immunotherapy.

Correlation of Programmed Death-Ligand 1 Expression With Lung Adenocarcinoma Histologic and Molecular Subgroups in Primary and Metastatic Sites

Programmed death-ligand 1 (PD-L1) expression in terms of the tumor proportion score (TPS) is the main predictive biomarker approved for immunotherapy against lung nonsmall cell carcinoma. Although some studies have explored the associations between histology and PD-L1 expression in pulmonary adenocarcinoma, they have been limited in sample size and/or extent of examined histologic variables, which may have resulted in conflicting information. In this observational retrospective study, we identified primary and metastatic lung adenocarcinoma cases in the span of 5 years and tabulated the detailed histopathologic features, including pathological stage, tumor growth pattern, tumor grade, lymphovascular and pleural invasion, molecular alterations, and the associated PD-L1 expression for each case. Statistical analyses were performed to detect associations between PD-L1 and these features. Among 1658 cases, 643 were primary tumor resections, 751 were primary tumor biopsies, and 264 were metastatic site biopsies or resections. Higher TPS significantly correlated with high-grade growth patterns, grade 3 tumors, higher T and N stage, presence of lymphovascular invasion, and presence of MET and TP53 alterations, whereas lower TPS correlated with lower-grade tumors and presence of EGFR alterations. There was no difference in PD-L1 expression in matched primary and metastases, although higher TPS was observed in metastatic tumors due to the presence of high-grade patterns in these specimens. TPS showed a strong association with a histologic pattern. Higher-grade tumors had higher TPS, which is also associated with more aggressive histologic features. Tumor grade should be kept in mind when selecting cases and blocks for PD-L1 testing.

PD-L1 (22C3) Expression Correlates with Clinical and Molecular Features of Lung Adenocarcinomas in Cytological Samples

INTRODUCTION

PD-L1 expression is the most widely used predictive marker for immune checkpoint inhibitor (ICI) therapy in patients with lung adenocarcinoma. However, the current understanding of the association between PD-L1 expression and treatment response is suboptimal. A significant percentage of patients have only a cytological specimen available for clinical management. Therefore, it is relevant to examine the impact of molecular features on PD-L1 expression in cytological samples and how it might correlate with a therapeutic response.

METHODS

We evaluated patients diagnosed with adenocarcinoma of the lung who had both in-house targeted next-generation sequencing analysis and paired PD-L1 (22C3) immunohistochemical staining performed on the same cell blocks. We explored the association between molecular features and PD-L1 expression. In patients who underwent ICIs therapy, we assessed how a specific gene mutation impacted a therapeutic response.

RESULTS

145 patients with lung adenocarcinoma were included in this study. PD-L1-high expression was found to be more common in pleural fluid than in other sample sites. Regional lymph node samples showed a higher proportion of PD-L1-high expression (29%) compared with lung samples (6%). The predictive value of PD-L1 expression was retained in cytological samples. Mutations in KRAS were also associated with a PD-L1-high expression. However, tumors with TP53 or KRAS mutations showed a lower therapy response rate regardless of the PD-L1 expression.

CONCLUSION

Cytological samples maintain a predictive value for PD-L1 expression in patients with lung adenocarcinoma as regards the benefit of ICI treatment. Specific molecular alterations additionally impact PD-L1 expression and its predictive value.

Artificial intelligence and digital biomarker in precision pathology guiding immune therapy selection and precision oncology

BACKGROUND

The currently available immunotherapies already changed the strategy how many cancers are treated from first to last line. Understanding even the most complex heterogeneity in tumor tissue and mapping the spatial cartography of the tumor immunity allows the best and optimized selection of immune modulating agents to (re-)activate the patient's immune system and direct it against the individual cancer in the most effective way.

RECENT FINDINGS

Primary cancer and metastases maintain a high degree of plasticity to escape any immune surveillance and continue to evolve depending on many intrinsic and extrinsic factors In the field of immune-oncology (IO) immune modulating agents are recognized as practice changing therapeutic modalities. Recent studies have shown that an optimal and lasting efficacy of IO therapeutics depends on the understanding of the spatial communication network and functional context of immune and cancer cells within the tumor microenvironment. Artificial intelligence (AI) provides an insight into the immune-cancer-network through the visualization of very complex tumor and immune interactions in cancer tissue specimens and allows the computer-assisted development and clinical validation of such digital biomarker.

CONCLUSIONS

The successful implementation of AI-supported digital biomarker solutions guides the clinical selection of effective immune therapeutics based on the retrieval and visualization of spatial and contextual information from cancer tissue images and standardized data. As such, computational pathology (CP) turns into "precision pathology" delivering individual therapy response prediction. Precision Pathology does not only include digital and computational solutions but also high levels of standardized processes in the routine histopathology workflow and the use of mathematical tools to support clinical and diagnostic decisions as the basic principle of a "precision oncology".

Sintilimab plus docetaxel as second-line therapy of advanced non-small cell lung cancer without targetable mutations: a phase II efficacy and biomarker study

BACKGROUND

Single-agent immunotherapy is currently the recommended second-line therapy for patients with advanced non-small cell lung cancer (NSCLC) without targetable mutations; however, the objective response rate (ORR) remains low. This phase II study evaluated the efficacy of the combination therapy of sintilimab plus docetaxel and explored potential biomarkers for efficacy prediction.

METHODS

Thirty patients with NSCLC without targetable mutations whose disease progressed from first-line platinum-based chemotherapy from October 2019 to December 2020 were enrolled in this single-arm, single-center, phase II trial. Sintilimab (200 mg) and docetaxel (75 mg/m²) were administered every 3 weeks until progression. The primary endpoint was ORR. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Biomarker analyses of blood and tissue samples were also performed.

RESULTS

Among 30 patients, 11 patients had partial response, resulting in an ORR of 36.7%. The median PFS was 5.0 months (95%CI: 3.9-6.1) and OS was 13.4 months (95%CI: 5.6-21.2). The most common immune-related adverse event of any grade was hepatitis, observed in 23.3% (7/30) of patients. Treatment-emergent adverse events were manageable. Patients detected with high PD-L1 expression in circulating tumor cells (cutoff value ≥32.5% based on the median CTC-PD-L1 expression) achieved significantly higher ORR (60% versus 13.3%, p = 0.021) and significantly longer median PFS (6.0 versus 3.5 months, p = 0.011) and median OS (15.8 versus 9.0 months, p = 0.038) than those with low CTC-PD-L1 level. Patients detected with PD-L1 < 1% and CD8 ≥ 1% expression from their baseline tissue samples had significantly higher ORR (83.3% versus 12.5%, p = 0.026) but similar PFS (p = 0.62) and OS (p = 0.15).

CONCLUSION

This study demonstrated the effectiveness and safety of sintilimab plus docetaxel as a second-line treatment of NSCLC without targetable mutations after progression from first-line platinum-based chemotherapy.

TRIAL REGISTRATION

This study was registered in the Clinical trials registry with ClinicalTrials.gov Identifier NCT03798743 (SUCCESS).

Malignant pleural effusion cell blocks are reliable resources for PD-L1 analysis in advanced lung adenocarcinomas: a concordance study with matched histologic samples

INTRODUCTION

In lung cancer patients presenting with malignant pleural effusion (MPE), cytology might represent the only source of tumor tissue for diagnosis and predictive biomarker testing. Programmed death ligand 1 (PD-L1) expression in tumor cells is a predictive biomarker for immunotherapy in non-small cell lung carcinomas and is tested using immunohistochemistry. However, knowledge of the validity of PD-L1 testing on MPE samples is limited. We evaluated the feasibility of immunocytochemistry (ICC) for PD-L1 in MPE cell blocks (CBs) and assessed the concordance in expression with patient-matched histologic samples.

MATERIALS AND METHODS

ICC for PD-L1 was performed on formalin-fixed paraffin-embedded CBs of MPE and patient-matched histologic samples, if available, using the automated Ventana PD-L1 SP263 assay. The tumor proportion score (TPS), based on partial or complete membranous tumor cell staining, was categorized as negative (&lt;1%), low (≥1% to &lt;50%), and high (≥50%). In CBs with any degree of PD-L1 expression, ICC for CD163 highlighting macrophages was performed to exclude nonspecific PD-L1 expression in macrophages. The CB PD-L1 TPS was compared with the TPS obtained from the patient-matched histologic samples.

RESULTS

Of 43 MPE CBs available, 25 were positive for PD-L1 (25 of 42; 59%), and 1 sample was inadequate. Of the 11 patient-matched histologic samples tested, the PD-L1 TPS categories were concordant for 10 of the 11 (91% concordance) cases.

CONCLUSIONS

PD-L1 expression in MPE CBs showed good concordance with expression in histologic samples and is feasible as a source for PD-L1 testing. The concurrent use of CD163 immunostains will aid in the manual assessment of PD-L1 TPS.

Efficacy of nivolumab as second line treatment for recurrent or metastatic head and neck squamous cell carcinoma: a national DAHANCA cohort study

INTRODUCTION

The aim of this study was to investigate phase IV efficacy, of the PD-1 inhibitor nivolumab among an unselected and unbiased national cohort of recurrent/metastatic Head and Neck Squamous Cell Carcinoma (rmHNSCC) patients.

MATERIAL AND METHODS

Inclusion criteria included histologically confirmed rmHNSCC and nivolumab as a second-line palliative treatment. Data were collected from patient files at the five Danish head and neck cancer centers and from the DAHANCA database. The iRECIST criteria were used for treatment evaluation.Endpoints were response rate (RR), overall survival (OS), and progression-free survival (PFS), calculated from the start of treatment to the date of event/censoring by the KM-method. Descriptive statistics were used to describe patients and treatment. Analyses were two-sided, with p < .05 considered significant.

RESULTS

A total of 146 patients were identified in the period 2017-2020. They had a RR of 14%, median OS of 10.2 months [95% CI: 8.2-12.2] and median PFS of 3.1 months [95% CI: 2.3-4.2]. Patient age (≥ 70 years) or comorbidity did not significantly affect outcome. WHO performance status (PS) =1 was associated with an increased risk of death (HR: 2.1 [95% CI: 1.2-4.0], p = .02) and progression (HR: 1.9 [95% CI: 1.2-3.2], p = .01). Concomitant glucocorticoid-treatment during immunotherapy (≥ 50% of treatment time) appeared important for risk of death (HR: 6.4 [95% CI: 2.3-17.8], p < .001) and risk of progression (HR: 4.8 [95% CI: 1.8-12.5], p = .001). PD-L1 expression ≥ 20% was associated with a lowered risk of progression (HR: 0.5 [95% CI: 0.3-0.7], p = .001), but not lowered risk of death.

CONCLUSION

In this unselected national cohort, outcome of second-line treatment reflects data from the registration studies. Furthermore, the results suggest that immunotherapy should be used with great care in treatment of rmHNSCC in patients with poor performance.

Immunotherapy in NSCLC Patients with Brain Metastases

Approximately 40% of unselected non-small cell lung cancer (NSCLC) patients develop brain metastases (BMs) during their disease, with considerable morbidity and mortality. The management of BMs in patients with NSCLC is a clinical challenge and requires a multidisciplinary approach to gain effective intracranial disease control. Over the last decade, immune checkpoint inhibitors (ICIs) have emerged as a game-changer in the treatment landscape of advanced NSCLC, with significant improvements in survival outcomes, although patients with BMs are mostly underrepresented in randomized clinical trials. Moreover, the safety and activity of ICIs and radiotherapy combinations compared with single-agent or sequential modalities is still under evaluation to establish the optimal management of these patients. The aim of this review is to summarize the state-of-the-art of clinical evidence of ICIs intracranial activity and the main challenges of incorporating these agents in the treatment armamentarium of NSCLC patients with BMs.

[Comparative Study of PD-L1 Expression in Different Sites of Non-small Cell Lung Cancer]

BACKGROUND

The expression of programmed cell death ligand 1 (PD-L1) as a biomarker for immunotherapy in non-small cell lung cancer (NSCLC) is routinely detected in clinical pathology department. However, the spatial heterogeneity of PD-L1 expression in intrapulmonary tumors and extrapulmonary metastases is still a challenge for the clinical testing. This study aims to explore the differences of PD-L1 expression in test samples obtaining from different sites of NSCLC. This study may contribute to the detection strategy of PD-L1 in patients with advanced lung cancer.

METHODS

One hundred and thirty-one cases of consecutively detected PD-L1 (22c3 assay, Dako) staining in metastatic NSCLC and 972 cases of non-paired intrapulmonary NSCLC were collected. The discrepancies of tumor proportion score (TPS) of PD-L1 expression in intrapulmonary samples and extrapulmonary metastatic samples of different sites were compared.

RESULTS

The positive expression rate of PD-L1 in extrapulmonary metastatic NSCLC (TPS ≥ 1%) was 61.83%, and the TPS was significantly higher than that in intrapulmonary tumors (P=0.03). The PD-L1 scores of the specimens obtained from different sites were significantly different (P=0.007). The positive rates of PD-L1 in liver and adrenal metastases were 85.71% and 77.78% respectively, and their TPS were significantly higher than that of the intrapulmonary samples (P<0.05). The positive rates of PD-L1 in lymph node, bone, brain, soft tissue, and pleural metastases was 40.00%-66.67%, with no significant differences compared to intrapulmonary tumors. The analysis of histological subtype and sample type showed that the PD-L1 score of extrapulmonary samples of adenocarcinoma subtype or surgical specimen was significantly higher than that of intrapulmonary tumors. The analysis of clinicopathological parameters showed that the PD-L1 positive expression or high expression were significantly correlated with male patients, smoking history, and epidermal growth factor receptor (EGFR) wild type.

CONCLUSIONS

The expression of PD-L1 in metastatic NSCLC is generally higher than that in intrapulmonary tumor, and the positive rate of PD-L1 expression was discrepant in different sites of specimen. The differences of PD-L1 score between extrapulmonary metastatic samples and intrapulmonary samples may be associated with different metastatic sites, histological subtype, and specimen type.

Different In Situ Immune Patterns between Primary Tumor and Lymph Node in Non-Small-Cell Lung Cancer: Potential Impact on Neoadjuvant Immunotherapy

Background

Neoadjuvant immunotherapy is promising for locally advanced non-small-cell lung cancer (NSCLC). The in situ immune patterns, as a predictor of PD-1/PD-L1 blockade outcomes, of the primary tumor (PT) and metastatic lymph nodes (mLNs) are unknown.

Methods

Multiplex immunofluorescence staining and multispectral imaging were used to evaluate the in situ immune patterns of T cells (CD3+) and cytotoxic T cells (CD8+) in terms of density, location (center of tumor (CT) and invasive margin (IM)), and the PD-L1 expression status of tumor cells and stromal T cells of paired PTs and mLNs in 38 stage III NSCLCs.

Results

The densities of T cells and cytotoxic T cells were correlated between PTs and mLNs at both CT and IM. Higher densities of stromal T cells (S-CD3+) at CT and both S-CD3+ and cytotoxic T cells (S-CD8+) at IM were observed in mLNs compared to PTs, while in tumor compartment, there were no differences in the densities of T cells (T-CD3+) or cytotoxic T cells (T-CD8+). Only the density of stromal PD-L1-positive T cells (S-PD-L1+CD3+) at CT was correlated between PTs and mLNs, while the densities and frequencies of S-PD-L1+CD3+ at CT and IM of mLNs were higher than PTs. Combining positive score discordance of PD-L1 between PTs and mLNs was greater than tumor proportion score. Conclusions. In situ immune patterns of T cells and cytotoxic T cells were different between PTs and mLNs in NSCLC. The heterogeneity of the in situ immune patterns may result in different immune-mediated responses to neoadjuvant immunotherapy in PT and mLNs.

Suitability of endobronchial ultrasound-guided transbronchial needle aspiration samples for programmed death ligand-1 testing in non-small cell lung cancer, the Bristol experience

Treatment for non-small cell lung cancer (NSCLC) is now personalised using molecular mutation testing. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) biopsy suitability for anaplastic lymphoma kinase (ALK) and epidermal growth factor receptor (EGFR) mutation testing is established. Less is currently known about EBUS-TBNA suitability for PD-L1 (programmed death ligand-1) testing. To assess EBUS-TBNA biopsy adequacy for ALK, EGFR and PD-L1 testing, we conducted a prospective study of 279 consecutive NSCLC patients referred to a tertiary EBUS-TBNA centre in South West England. One hundred eight-four (62.6%) patients were found to have adenocarcinoma, 83 (28.2%) had squamous cell carcinoma, and 27 (9.2%) were identified as NSCLC-not otherwise specified. EGFR testing was successful in 166 of 168 patients (98.8%), ALK testing in all 115 and PD-L1 testing in 43 of 49 patients (88.2%). Previous EGFR and ALK testing did not affect biopsy PD-L1 testing success. PD-L1 testing failures occurred in three of five (60.0%) of 22G needle biopsies, one of five (20.0%) of 21G needle biopsies and two of 39 (5.1%) of 19G needle biopsies, P = .016. EBUS-TBNA biopsies are mostly suitable for PD-L1 testing. Larger needle size may improve PD-L1 (but not EGFR and ALK) testing success but requires further study in a controlled trial.

Preclinical Pharmacokinetics and Dosimetry of an 89Zr Labelled Anti-PDL1 in an Orthotopic Lung Cancer Murine Model

Anti-PDL1 is a monoclonal antibody targeting the programmed death-cell ligand (PD-L1) by blocking the programmed death-cell (PD-1)/PD-L1 axis. It restores the immune system response in several tumours, such as non-small cell lung cancer (NSCLC). Anti-PDL1 or anti-PD1 treatments rely on PD-L1 tumoural expression assessed by immunohistochemistry on biopsy tissue. However, depending on the biopsy extraction site, PD-L1 expression can vary greatly. Non-invasive imaging enables whole-body mapping of PD-L1 sites and could improve the assessment of tumoural PD-L1 expression.

Methods

Pharmacokinetics (PK), biodistribution and dosimetry of a murine anti-PDL1 radiolabelled with zirconium-89, were evaluated in both healthy mice and immunocompetent mice with lung cancer. Preclinical PET (μPET) imaging was used to analyse [89Zr]DFO-Anti-PDL1 distribution in both groups of mice. Non-compartmental (NCA) and compartmental (CA) PK analyses were performed in order to describe PK parameters and assess area under the concentration-time curve (AUC) for dosimetry evaluation in humans.

Results

Organ distribution was correctly estimated using PK modelling in both healthy mice and mice with lung cancer. Tumoural uptake occurred within 24 h post-injection of [89Zr]DFO-Anti-PDL1, and the best imaging time was at 48 h according to the signal-to-noise ratio (SNR) and image quality. An in vivo blocking study confirmed that [89Zr]DFO-anti-PDL1 specifically targeted PD-L1 in CMT167 lung tumours in mice. AUC in organs was estimated using a 1-compartment PK model and extrapolated to human (using allometric scaling) in order to estimate the radiation exposure in human. Human-estimated effective dose was 131 μSv/MBq.

Conclusion

The predicted dosimetry was similar or lower than other antibodies radiolabelled with zirconium-89 for immunoPET imaging.

Study on PD-L1 Expression in NSCLC Patients and Related Influencing Factors in the Real World

PD-L1 is one of the current biomarkers for immune checkpoint inhibitor (ICI) therapy in patients with non-small-cell lung cancer. However, the expression of PD-L1 in the real world and its related influencing factors remain unclear. We want to observe the expression of PD-L1 in the real world and study the related influencing factors through the collection and analysis of clinical data. R software (version 4.0) was used to perform data analysis and the “corplot” package for correlation analysis. A total of 296 individuals (mean [SD] age, 67 [9] years; 23%female) were assessed. According to the expression amount of PD-L1, the cohort was divided into low nonexpression group (PD‐L1 < 1%, 26.7%), low-expression group (1% ≤ PD‐L1 < 50%, 49.3%), and high-expression group (PD‐L1 ≥ 50%, 23.5%). Age, gender, underlying diseases, smoking status, and PD-L1 expression level were not statistically significant. We found that the expression of PD-L1 was correlated with serum albumin (P < 0.05) and pathological type (P < 0.05) and had a negative correlation with EGFR mutation but did not correlate with gender, age, smoking status, combined with underlying diseases, tumor stage, whether it was initially treated or not, sampling site, specimen type, specimen storage time, R-IFN, CD4, CD8, NLR, CRP, and LDH. The present findings indicated that serum albumin, pathological type, and EGFR mutations are associated with PD-L1 expression in patients with NSCLC, which may provide a new basis for individualized immunotherapy and need further study to confirm. The results of this study help to further reveal the actual expression of PD-L1 in non-small-cell lung cancer patients with real events.

Actionable Molecular Alterations Are Revealed in Majority of Advanced Non-Small Cell Lung Cancer Patients by Genomic Tumor Profiling at Progression after First Line Treatment

Background: Genomic profiling in advanced Non-Small Cell Lung cancer (NSCLC) can reveal Actionable Molecular Alterations (AMAs). Our study aims to investigate clinical relevance of re-biopsy after first line treatment, by reporting on acquired and persistent AMAs and potential targeted treatments in a real-time cohort of NSCLC patients. Methods: Patients with advanced NSCLC receiving first-line treatment were prospectively included in an observational study (NCT03512847). Genomic profiling was performed by TruSight Oncology 500 HT gene panel on tumor tissue collected at diagnosis and at time of progression. Results: The 92 patients re-biopsied at progression had received immunotherapy (n = 44), chemotherapy (n = 44), or combination treatment (n = 4). In 87 of these patients (95%), successful genomic profiling was performed at both the diagnostic biopsy and the re-biopsy. In 74 patients (85%), ≥1 AMA were found. The AMAs were acquired in 28%. The most frequent AMAs were observed in TP53 (45%), KRAS (24%), PIK3CA (6%), and FGFR1 (6%). Only five patients (5%) received targeted treatment mainly due to deterioration in performance status. Conclusions: Re-biopsy at progression revealed acquired AMAs in approximately one third of patients, and 85% had at least one AMA with the potential of receiving targeted treatment, thus strengthening the clinical relevance of re-biopsy.

PD-L1 and PD-L2 expression status in relation to chemotherapy in primary and metastatic esophageal squamous cell carcinoma

Immune checkpoint inhibitors have shown efficacy in various cancers. Although programmed death ligand 1/2 (PD‐L1/L2) expressions have been demonstrated as predictive biomarkers of response to immune checkpoint inhibitors and prognostic markers, whether PD‐L1/L2 expression is altered in esophageal squamous cell carcinoma during the therapeutic course is unclear. Whether PD‐L1/L2 expression in metastatic or recurrent lesions is consistent with that in primary tumors is also unknown. This study included 561 surgically resected esophageal squamous cell carcinomas and PD‐L1/L2 expression was evaluated by immunohistochemistry. We investigated the influence of chemotherapeutic drugs (cisplatin and fluorouracil) on PD‐L1/L2 expression and PD‐L1/L2‐related pathways in vitro. We also examined PD‐L1/L2 expression in 18 surgically resected lymph node metastases and 10 recurrent lesions compared with primary lesions. The positive rate of PD‐L1 was significantly higher in patients with preoperative chemotherapy than in those without preoperative therapy. The positive rate of PD‐L2 expression showed no significant difference between patient groups. Cisplatin increased PD‐L1 expression in cancer cell lines in vitro, but decreased PD‐L2 in some cell lines. The effects of cisplatin on phosphorylated signal transducer and activator of transcription 1/3 (pSTAT1/3) also differed depending on cell lines. Fluorouracil increased PD‐L1 and PD‐L2 expression. PD‐L1/L2 expression in lymph node metastases and recurrent lesions did not always match expression in primary lesions. PD‐L1/L2 expression may be altered by preoperative chemotherapy, and PD‐L1 /L2 expression in primary lesions does not always match that of metastatic/recurrent lesions. Thus, one‐time evaluation is not sufficient to evaluate PD‐L1/L2 expression as a biomarker in esophageal cancer.

Comparison of Tumor Microenvironments Between Primary Tumors and Brain Metastases in Patients With NSCLC

Introduction

This study investigates the immune profile of the primary lung tumors and the corresponding brain metastasis from patients with NSCLC using multiplex fluorescence immunohistochemistry.

Methods

The study evaluated 34 patients who underwent autopsy or surgical resection for brain metastasis and autopsy, surgical resection, or core biopsy for primary lung cancer. We compared the densities of various immune cells in the primary tumors and the brain metastases by multiplex fluorescence immunohistochemical analysis.

Results

The density of CD4-positive (CD4⁺) T-cells, CD8-positive T-cells, and CD4⁺ Foxp3-positive T-cells were statistically higher in both tumor and stromal areas in primary lung cancer specimens when compared with brain metastases samples (p < 0.0001). Only CD204-positive cells were statistically higher in the tumor areas of the brain metastases (p = 0.0118). Tumor-infiltrating lymphocytes associated with brain metastases positively correlated with overall survival, but primary lung tumor-infiltrating lymphocytes did not. The density of CD4⁺ and CD4⁺ Foxp3-positive T-cells in brain metastases with radiation was statistically higher in the carcinoma and stromal areas compared with those without radiation (p = 0.0343, p = 0.0173).

Conclusions

Our findings that CD204-positive cells were higher in brain metastases may have broader implications for treatment as these macrophages may be immunosuppressive and make the immune environment less reactive. Furthermore, the finding that the density of CD4⁺ T-cells was higher in cancer and stroma areas of brain metastases after radiotherapy supports the addition of immunotherapy to radiation therapy in the treatment of brain metastases in NSCLC.

Prognostic significance of programmed cell death-ligand 1 expression on circulating tumor cells in various cancers: A systematic review and meta-analysis

Background

The prognostic significance of programmed cell death‐ligand 1 (PD‐L1) expression on circulating tumor cells (CTCs) has been explored but is still in controversy. We performed, for the first time, a meta‐analysis to systematically evaluate its prognostic value in human cancers.

Methods

Literature databases were searched for eligible studies prior to June 30, 2021. The pooled hazard ratios (HRs) and 95% confidence intervals (95% CIs) were calculated for the associations of pre‐treatment and post‐treatment PD‐L1⁺ CTCs with progression‐free survival (PFS) and overall survival (OS). Subgroup analyses with regards to cancer type, treatment, CTC enrichment method, PD‐L1 detection method, cut‐off, and specifically the comparison model were performed.

Results

We included 30 eligible studies (32 cohorts, 1419 cancer patients) in our analysis. Pre‐treatment PD‐L1⁺ CTCs detected by immunofluorescence (IF) tended to predict better PFS (HR = 0.55, 95% CI 0.28–1.08, p = 0.084) and OS (HR = 0.61, 95% CI 0.36–1.04, p = 0.067) for immune checkpoint inhibitor (ICI) treatment, but were significantly associated with unfavorable survival for non‐ICI therapies (PFS: HR = 1.85, 95% CI 1.21–2.85, p = 0.005; OS: HR = 2.44, 95% CI 1.69–3.51, p < 0.001). Post‐treatment PD‐L1⁺ CTCs predicted markedly worse PFS and OS. The prognostic value was obviously modulated by comparison models. Among patients with detectable CTCs, PD‐L1⁺ individuals had comparable survival to PD‐L1⁻ individuals, except ICI treatment for which PD‐L1⁺ may predict better PFS (HR = 0.42, 95% CI 0.17–1.06, p = 0.067). Patients with PD‐L1⁺ CTCs had worse survival prognosis compared to those without PD‐L1⁺ CTCs in overall analysis (PFS: HR = 2.10, 95% CI 1.59–2.77, p < 0.001; OS: HR = 2.55, 95% CI 1.70–3.81, p < 0.001) and in most subgroups.

Conclusions

Our analysis demonstrated that PD‐L1 positive expression on CTCs predicted better survival prognosis for ICI treatment but worse survival for other therapies, which thus can be potentially used as a prognostic marker of malignant tumor treatment. However, the prognostic value of PD‐L1⁺ CTCs for ICI treatment needs validation by more large‐scale studies in the future.

PD-L1 Expression in Non-Small Cell Lung Cancer: Data from a Referral Center in Spain

Anti-programmed cell death (PD1)/ligand-1 (PD-L1) checkpoint inhibitors have improved the survival of non-small cell lung cancer (NSCLC) patients. Additionally, PD-L1 has emerged as a predictive biomarker of response. Our goal was to examine the histological features of all PD-L1 cases of NSCLC analyzed in our center between 2017 and 2020, as well as to correlate the expression values of the same patient in different tested samples. PD-L1 immunohistochemistry (IHC) was carried out on 1279 external and internal samples: 482 negative (tumor proportion score, TPS < 1%; 37.7%), 444 low-expression (TPS 1–49%; 34.7%) and 353 high-expression (TPS ≥ 50%; 27.6%). Similar results were observed with samples from our institution (N = 816). Significant differences were observed with respect to tumor histological type (p = 0.004); squamous carcinoma was positive in a higher proportion of cases than other histological types. There were also differences between PD-L1 expression and the type of sample analyzed (surgical, biopsy, cytology; p < 0.001), with a higher frequency of negative cytology. In addition, there were cases with more than one PD-L1 determination, showing heterogeneity. Our results show strong correlation with the literature data and reveal heterogeneity between tumors and samples from the same patient, which could affect eligibility for treatment with immunotherapy.

Feasibility and reliability of evaluate PD-L1 expression determination using small biopsy specimens in non-small cell lung cancer

BACKGROUND

Programmed cell death ligand-1 (PD-L1) is a useful biomarker in non-small cell lung cancer (NSCLC) patients who would probably benefit from immunotherapy. In most patients with advanced stage NSCLC, only small biopsy specimens were available for the evaluation of PD-L1 expression. In this study, we evaluated the feasibility and reliability of PD-L1 testing on small biopsy samples.

METHODS

Small specimens of advanced NSCLC patients obtained via endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA), endobronchial biopsy (EBB), or computed tomography (CT)-guided core-needle biopsy were collected. Tumor cell count and tissue sufficiency for PD-L1 immunohistochemistry (IHC) were evaluated and compared. The clinical course of patients who received immunotherapy in the study population was also examined.

RESULTS

Tissue acquisitions for PD-L1 testing in three groups were all above 90%, with no statistically significant differences. The PD-L1 expressions levels were concordant in most patients with more than one sample (8/11). In the EBB group, PD-L1-positive patients had higher objective response rate (ORR) (53.2% vs. 26.9%, p = 0.048) and longer progression-free survival (PFS) (312 vs. 179 days, p = 0.035) than PD-L1 negative patients. In the core needle biopsy group, patients with positive PD-L1 expression also trended to have higher ORR and longer PFS. However, in the EBUS-TBNA group, both ORR and PFS were similar between patients with positive or negative PD-L1 expression.

CONCLUSIONS

This study showed that EBUS-TBNA, EBB, and core needle biopsy provides adequate samples for PD-L1 testing. The predictive value of PD-L1 expression on different small samples still warrants further studies.

Immunotherapy in Non-Small Cell Lung Cancer Patients with Brain Metastases: Clinical Challenges and Future Directions

Immune checkpoint inhibitors have revolutionized the treatment landscape for patients with non-small cell lung cancers. Existing treatment paradigms for brain metastases in lung cancer patients leave patients with adverse neurocognitive function, poor quality of life, and dismal prognosis, thus highlighting the need to develop more effective systemic therapies. Although data are limited, emerging knowledge suggests promising activity and safety of immune checkpoint inhibitors in brain metastases in non-small cell lung cancer patients. This review aims to summarize the current data, highlight the challenges of incorporating immune checkpoint inhibitors in treating these patients, and identify areas for future research.

Immune checkpoint inhibitors for brain metastases in non-small-cell lung cancer: from rationale to clinical application

Brain metastases (BM) is common in non-small-cell lung cancer (NSCLC) patients. Immune checkpoint inhibitors (ICIs) have gradually become a routine treatment for NSCLC BM patients. Currently, three PD-1 inhibitors (pembrolizumab, nivolumab and cemiplimab), one PD-L1 inhibitor (atezolizumab) and one CTLA-4 inhibitor (ipilimumab) have been approved for the first-line treatment of metastatic NSCLC. It is still controversial whether PD-L1, tumor infiltrating lymphocytes, and tumor mutation burden can be used as predictive biomarkers for immune checkpoint inhibitors in NSCLC patients with BM. In addition, clinical data on NSCLC BM were inadequate. Here, we review the theoretical basis and clinical data for the application of ICIs in the therapy of NSCLC BM.

Temporal evolution of programmed death-ligand 1 expression in patients with non-small cell lung cancer

BACKGROUND/AIMS

Programmed death-ligand 1 (PD-L1) expression, a validated predictive biomarker for anti-PD-1/PD-L1 inhibitors, is reported to change over time. This poses challenges during clinical application in non-small cell lung cancer.

METHODS

This study included patients with non-small cell lung cancer who underwent surgery or biopsy and evaluation of PD-L1 expression in tumor cells via immunohistochemistry more than twice. We set the threshold of PD-L1 positivity to 10% and categorized patients into four groups according to changes in PD-L1 expression. Clinicopathologic information was collected from medical records. Statistical analyses, including Fisher's exact test and log-rank test, were performed.

RESULTS

Of 109 patients, 38 (34.9%) and 45 (41.3%) had PD-L1 positivity in archival and recent samples, respectively. PD-L1 status was maintained in 78 (71.6%) patients, but changed in 31 (28.4%), with 19 (17.4%) from negative to positive. There were no significant differences in characteristics between patients who maintained PD-L1 negativity and whose PD-L1 status changed from negative to positive. Patients harboring PD-L1 positivity in either archival or recent samples achieved better responses (p = 0.129) and showed longer overall survival than those who maintained PD-L1 negativity when they received immune checkpoint inhibitors after platinum failure (median overall survival 14.4 months vs. 4.93 months; hazard ratio, 0.43; 95% confidence interval, 0.20 to 0.93).

CONCLUSION

PD-L1 status changed in about one-fourth of patients. PD-L1 positivity in either archival or recent samples was predictive of better responses to immune checkpoint inhibitors. Therefore, archival samples could be used for assessment of PD-L1 status. The need for new biopsies should be decided individually.

Selecting the optimal immunotherapy regimen in driver-negative metastatic NSCLC

The treatment landscape of driver-negative non-small-cell lung cancer (NSCLC) is rapidly evolving. Immune-checkpoint inhibitors, specifically those targeting PD-1 or PD-L1, have demonstrated durable efficacy in a subset of patients with NSCLC, and these agents have become the cornerstone of first-line therapy. Approved immunotherapeutic strategies for treatment-naive patients now include monotherapy, immunotherapy-exclusive regimens or chemotherapy-immunotherapy combinations. Decision making in this space is complex given the absence of head-to-head prospective comparisons, although a thorough analysis of long-term efficacy and safety data from pivotal clinical trials can provide insight into the optimal management of each subset of patients. Indeed, histological subtype and the extent of tumour cell PD-L1 expression are paramount to regimen selection, although other clinicopathological factors and patient preferences might also be relevant in certain scenarios. Finally, several emerging biomarkers and novel therapeutic strategies are currently under investigation, and these might further refine the current treatment paradigm. In this Review, we discuss the current treatment landscape and detail our approach to first-line immunotherapy regimen selection for patients with advanced-stage, driver-negative NSCLC.

PD-L1 expression and its clinicopathologic and genomic correlation in the non-small cell lung carcinoma patients: An Indian perspective

BACKGROUND

Immunotherapy with checkpoint inhibitor programmed death-1 (PD-1) and programmed death-ligand 1 (PD-L1) antibodies targeting the cellular immune checkpoints is the present area of interest showing promising results in patients with advanced non-small cell lung cancer (NSCLC). As there is paucity of PD-L1 expression data from the Indian perspective, we studied the correlation of clinicopathologic profile and oncogenic driver mutations in these patients.

MATERIALS AND METHODS

Samples from 252 advanced NSCLCs patients were studied for PD-L1 expression through immunohistochemistry using rabbit anti-human PD-L1 monoclonal antibody (clone SP263) on Ventana BenchMark ULTRA autostainer. Simultaneously, genetic mutations were studied by next generation sequencing (for EGFR, ALK, ROS, MET, and BRAF). PD-L1 expression was analyzed for association with clinicopathologic features and various mutations.

RESULTS

PD-L1 positivity was seen in 134 patients (53.2 %). It was twice more prevalent in males than females. No significant correlation was observed between PD-L1 expression with age, gender, site of testing (primary vs. metastatic tumors), smoking status, tumor laterality, stage, or histologic type; however, there was significant difference among solid and acinar types of adenocarcinoma combined together vs. other adenocarcinoma subtypes (p = 0.013), and well and moderately differentiated vs. poorly differentiated tumors (p = 0.022). When types/extent of PD-L1 positivity (≥25 %) were compared with demographics, clinical, and pathologic variables, significant differences were observed across the tumor grades (high-grade vs. low-grade) (p = 0.009) and stages (p = 0.039). The PD-L1 expression failed to demonstrate any statistical significance with oncogenic drivers. High PD-L1 expression (TPS ≥ 50) was observed in 27.6 % patients, and it was more prevalent in female patients (32.4 %), aged ≥60 years (33.8 %), smokers (27.3 %), poorly differentiated (36.8 %) and stage IV tumors (28.2 %). Exon 19 deletion was more prevalent in PD-L1 negative tumors whereas exon 21 substitution (L858R) was seen more in PD-L1 positive tumors.

CONCLUSIONS

This is the largest Indian study demonstrating PD-L1 expression in NSCLC patients comparing with clinicopathologic and genomic parameters. PD-L1 expression was significantly associated with high-grade, solid, and acinar types of adenocarcinoma and advanced tumors. High PD-L1 expression was more prevalent in female patients, aged ≥60 years, smokers, and poorly differentiated and stage IV tumors (28.2 %). Exon 19 deletion was more in PD-L1 negative tumors whereas exon 21 substitution (L858R) was more in PD-L1 positive tumors. PD-L1 is a potential predictive marker stratifying patients who benefit from PD-1 pathway-targeted therapy.

Prevalence and Heterogeneity of PD-L1 Expression by 22C3 Assay in Routine Population-Based and Reflexive Clinical Testing in Lung Cancer

INTRODUCTION

Programmed death-ligand 1 (PD-L1) is used as a biomarker for anti-programmed cell death protein-1 (PD-1) or anti-PD-L1 immunotherapies in NSCLC. We report here the results of population-based PD-L1 testing using the 22C3 IHC pharmDx Assay (Agilent Technologies) in a large Canadian regional reference pathology laboratory.

METHODS

Testing was conducted reflexively on biopsies and resections for NSCLC during an 8-month period. Tumor proportion score (TPS) cutoffs for low and high expression were 1% and 50%, respectively.

RESULTS

Altogether, 2031 PD-L1 tests were performed on specimens from 1795 patients, with 107 inconclusive results (5.3%). Excluding cases with inconclusive/missing data, proportions for the remaining 1713 patients were 41.6% for TPS less than 1%, 28.6% for TPS 1% to 49%, and 29.8% for TPS greater than or equal to 50%. Higher PD-L1 expression rates were noted in EGFR wild-type versus mutant tumors (p < 0.001), squamous versus adenocarcinoma (p < 0.001), and metastatic versus primary tumors (p < 0.001). PD-L1 among 103 patients with paired biopsy and resection specimens revealed moderate concordance (κ = 0.67). A total of 52% (25 of 48) of biopsies with TPS less than 1% had TPS greater than 1% in resection, whereas 84.6% (22 of 26) of biopsies with TPS greater than or equal to 50% were concordant in resected tumors. Discordance rates between biopsy and resection were 71.4% for biopsies with less than 8 mm² total area, compared with 33.3% for biopsies with greater than or equal to 8 mm² area (p < 0.026). Concordance among 27 patients with paired primary lung and metastatic tumor biopsies revealed only weak concordance (κ = 0.48).

CONCLUSIONS

Intratumoral heterogeneity of PD-L1 expression may result in misclassification of PD-L1 status in a substantial proportion of PD-L1-negative small biopsy samples. Biopsy of metastatic site may increase proportion of patients with high PD-L1 expression.

PD-L1 as a biomarker of response to immune-checkpoint inhibitors

Immune-checkpoint inhibitors targeting PD-1 or PD-L1 have already substantially improved the outcomes of patients with many types of cancer, although only 20-40% of patients derive benefit from these new therapies. PD-L1, quantified using immunohistochemistry assays, is currently the most widely validated, used and accepted biomarker to guide the selection of patients to receive anti-PD-1 or anti-PD-L1 antibodies. However, many challenges remain in the clinical use of these assays, including the necessity of using different companion diagnostic assays for specific agents, high levels of inter-assay variability in terms of both performance and cut-off points, and a lack of prospective comparisons of how PD-L1⁺ disease diagnosed using each assay relates to clinical outcomes. In this Review, we describe the current role of PD-L1 immunohistochemistry assays used to inform the selection of patients to receive anti-PD-1 or anti-PD-L1 antibodies, we discuss the various technical and clinical challenges associated with these assays, including regulatory issues, and we provide some perspective on how to optimize PD-L1 as a selection biomarker for the future treatment of patients with solid tumours.

PD-L1 versus tumor mutation burden: Which is the better immunotherapy biomarker in advanced non-small cell lung cancer?

PD-L1 and tumor mutation burden (TMB) are the most widely used immunotherapy biomarkers to identify populations who would attain clinical benefit, with the higher values predicting better therapeutic efficacy. This review addresses the predictive values and unresolved challenges of these two biomarkers. PD-1 and PD-L1 inhibitors have induced durable and effective responses in patients with advanced non-small cell lung cancer, confirmed by multiple clinical trials and real-world studies. Different clinical trials, involving both PD-1/PD-L1 inhibitors alone and combination regimens, adopted either PD-L1 or TMB to stratify the patients, although the predictive capabilities of these two biomarkers are different. In the first-line setting, PD-L1 of 50% or more as a cut-off value can help select candidates for pembrolizumab or atezolizumab monotherapy; however, these two biomarkers poorly predict the efficacy of immunotherapy combination regimens as first-line treatments. In the second-line setting, although patients can benefit from nivolumab regardless of PD-L1 expression, both PD-L1 and blood TMB can be used as biomarkers to find patients suitable for atezolizumab. Except for inaccurate predictiveness, there are many unresolved problems with regard to the two biomarkers, such as the lack of standard detection methods, and their susceptibilities to other dynamic changes. The predictive values of TMB and PD-L1 were low in most circumstances; however, PD-L1 expression greater than ≥ 50% can help select appropriate patients for pembrolizumab and atezolizumab, respectively, as first-line monotherapies. Higher PD-L1 or TMB was associated with greater efficacy for atezolizumab as a second-line monotherapy.

Predictive Biomarkers for Immune Checkpoint Inhibitors in Advanced Non-Small Cell Lung Cancer: Current Status and Future Directions

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment paradigm for advanced non-small cell lung cancer (NSCLC). Although certain patients achieve significant, long-lasting responses from checkpoint blockade, the majority of patients with NSCLC do not and may be unnecessarily exposed to inadequate therapies and immune-related toxicities. Therefore, there is a critical need to identify biomarkers predictive of immunotherapy response. While tumor and immune cell expression of programmed death ligand-1 and, more recently, tumor mutational burden are used in clinical practice and may correlate with immunotherapy response in selected circumstances, neither consistently predicts an individual patient's likelihood of clinical benefit from ICI therapy. More recently, innovative approaches such as blood-based assays and combination biomarker strategies are under active investigation. This review will focus on the current role and challenges of programmed death ligand-1 and tumor mutational burden as predictive biomarkers for immunotherapy response in advanced NSCLC and explore promising novel biomarker strategies.

Discordance of immunotherapy response predictive biomarkers between primary lesions and paired metastases in tumours: A systematic review and meta-analysis

Background

Several biomarkers predict the efficacy of immunotherapy, which is essential for selecting patients who would potentially benefit. Discordant status of these biomarkers between primary tumours and paired metastases has been increasingly revealed. We aimed to comprehensively summarize the incidence of this phenomenon.

Methods

Databases were searched to identify studies reporting primary-to-metastatic conversion of biomarkers, including programmed death ligand-1 (PD-L1), programmed cell death protein-1 (PD-1), PD-L2, tumour-infiltrating lymphocyte (TIL), tumour mutational burden (TMB), and microsatellite instability (MSI).

Findings

56 studies with 2739 patients were included. The pooled discordance rate of PD-L1 was 22%. The percentage of PD-L1 changed from positive to negative was 41%, whereas that from negative to positive was 16%. The discordance rate for PD-1 and PD-L2 was 26% and 22%, respectively. TIL level was found with a discordance rate of 39%, and changes from high to low (50%) occurred more than that from low to high (16%). No significant difference in TMB was observed between two sites in most studies. MSI status discordance was found in 6% patients, with a percentage of 9% from MSI-high to microsatellite instable (MSS) and 0% from MSS to MSI-high.

Interpretation

Our study demonstrates that PD-L1, PD-1, PD-L2, and TIL level had high frequency of discordance, while TMB and MSI status were less likely to change between primary tumours and paired metastases. Therefore, evaluating those frequently altered biomarkers of both primary and metastatic tumours is strongly recommended for precise clinical decision of immune checkpoint treatment.

Fund

The National Natural Science Foundation of China (81872152).

Clinical outcomes of immune checkpoint blockades and the underlying immune escape mechanisms in squamous and adenocarcinoma NSCLC

Immune checkpoint blockades (ICBs) have changed the standard of care of squamous and adenocarcinoma non‐small cell lung cancer (NSCLC). Whereas detailed researches regarding ICBs in the two major histological subtypes are rare. In order to uncover the clinical efficacy differences between squamous and adenocarcinoma NSCLC and better understand the underlying immune‐regulatory mechanisms, we compared the survival benefits of ICBs between the two subtypes by revealing phase 3 randomized trials and attempted to uncover the immune‐regulatory discrepancy. Generally, compared with nonsquamous NSCLC, squamous NSCLC benefited more from ICBs in Keynote 024, CheckMate 026, CheckMate 227 and CheckMate 017 and similar in OAK, but less in Keynote 010 and PACIFIC. We revealed that the tumor mutation burden (TMB) level, the programmed cell death ligand 1 (PD‐L1) expression, tumor infiltrating lymphocytes (TILs) in the tumor microenvironment (TME), chemokines, and oncogenic driver alterations within the two subtypes may contributed to the clinical outcomes of ICBs. We prospected that the combinations of ICBs with chemotherapy, radiation therapy, and antiangiogenic therapy could be promising strategies to re‐immunize the less immunogenic tumors and further enhance the efficacy of ICBs.

From clinical trials to clinical use of checkpoint inhibitors for patients with metastatic urothelial cancer

Monoclonal antibodies targeting the checkpoint inhibitors (CPIs), programmed cell death protein-1 or programmed cell death ligand-1, are changing the landscape of urothelial carcinoma therapeutics. Overall, clinical studies in metastatic or advanced urothelial cancer showed that CPIs provided a slight improvement in survival and a relevant advantage in safety, compared with chemotherapy. After reviewing published and ongoing trials, the authors discuss expected answers to unmet needs, with a special attention to the research of biological markers for patients with urothelial cancer eligible for treatment with CPIs in this article.

Re-biopsy after first line treatment in advanced NSCLC can reveal changes in PD-L1 expression

OBJECTIVES

Re-biopsy in progressive advanced Non-Small-Cell Lung Cancer (NSCLC) after first line treatment may reveal information about evolving tumor biology during treatment. Our study aims to investigate the feasibility, risk of complications, and clinical relevance of performing re-biopsy systematically.

MATERIALS AND METHODS

NSCLC patients with advanced, non-targetable disease, receiving first line systemic treatment, were included in a prospective single-centre study (NCT03512847). A diagnostic biopsy was performed at baseline and repeated at time of progression, preferentially from the progressive lesions as determined by CT or PET/CT. The primary endpoint was feasibility, including complication rate to re-biopsy. Secondary endpoints were clinical relevance, defined as a potential of changing treatment or follow-up, due to new histological evidence, specifically a change in PD-L1 Tumor Proportion Score (TPS).

RESULTS

Fifty-one patients with progressive advanced NSCLC had re-biopsy performed. Median time from patients' acceptance to biopsy was seven days (range: 0-31). Complication rate was 6% (n = 3) represented by pneumothorax, hydro-pneumothorax and pneumonia, respectively. No severe or chronic complications occurred. Sufficient material for PD-L1 analyses was obtained in 46 of 51 patients: the remaining five cases had insufficient tissue for analyses, no malignant cells/only suspected malignant cells, questioning whether progression was real. PD-L1 TPS change was observed in 33% of patients (n = 15) and 17% (n = 8) had potentially clinically relevant changes. A significantly higher chance of PD-L1 TPS change was observed in chemotherapy-treated patients.

CONCLUSION

Our study showed that re-biopsy is feasible, with low risk of complications, and can be clinically relevant in patients with suspected progression in advanced NSCLC.

Emerging role of immune checkpoint inhibitors and predictive biomarkers in head and neck cancers

Head and neck cancers are a group of diverse and heterogeneous tumors, among which squamous cell carcinoma of the head and neck (SCCHN) is the most prevalent. Current treatment modalities have limited efficacy; therefore, new therapies are being actively developed and evaluated. The introduction of immune checkpoint inhibitors (ICIs) has led to a paradigm shift in the management of difficult-to-treat malignancies. In this review, we summarize recent advances in the development of immunotherapies, which are aimed at the functional restoration of the immune system to counteract immune-evasion strategies of cancer cells, and related biomarkers. Monotherapies with ICIs, which primarily target the programmed cell death-1 (PD-1) pathway, have shown promising results in clinical trials of patients with recurrent and metastatic SCCHN. Combinations of ICIs with conventional or virus therapies often have synergistic therapeutic effects, without increased toxicity. As only a small subset of patients respond to immunotherapy, biomarkers are essential for the prediction of treatment response and better selection of patients for ICIs. PD-1 ligand (PD-L1) expression is correlated with response but has several limitations as a predictive marker, as its expression is dynamic and heterogeneous, and the cut-off needs further confirmation. Therefore, tumor mutation burden, gene expression signatures, microsatellite instability, tumor-infiltrating lymphocytes, viral antigens, and the oral microbiota are being investigated as predictive biomarkers. Finally, we delineate other challenges and future prospects for improving patient outcomes, including the major challenge of identifying and validating predictive biomarkers that need to be addressed in future studies.

Concordance of PD-L1 expression and CD8+ TIL intensity between NSCLC and synchronous brain metastases

Programmed death-ligand 1 (PD-L1) is suggested to be a predictive biomarker in non-small-cell lung carcinoma (NSCLC). However, the differential expression of PD-L1 in primary lung tumor vs. synchronous metastases, especially brain metastasis (BM), remains unclear. This study assessed the concordance of PD-L1 expression on tumor cells and tumor-infiltrating lymphocytes (TILs) and CD8⁺ TIL intensity between primary lung tumors and synchronous BMs from 24 NSCLC patients. PD-L1, CD3, and CD8 positivity was determined by immunohistochemistry (IHC). PD-L1 scoring was based on the proportion of tumor cells with membranous expression of PD-L1 and the cutoff values <1%, 1–49%, and ≥50%. CD3 and CD8 positivity in TILs was evaluated semi-quantitatively and the proportion of CD3⁺/CD8⁺ TILs was determined. PD-L1 expression on tumor cells and TILs was evaluated in relation to CD3⁺/CD8⁺ TIL proportions and the intensity of CD8⁺ TILs between the paired primary lung and BM tissues. In the primary lung tumors, PD-L1 positivity was observed in 25%, 37.5%, and 37.5% cases for the cutoff values <1%, 1–49%, and ≥50%, respectively. PD-L1 expression on tumor cells was strongly correlated between the paired primary lung and BM tissues, in all cutoff groups. However, PD-L1 expression on TILs and the proportion of CD3⁺/CD8⁺ TILs were not strongly correlated in all three groups between the paired primary lung tumors and BMs. The intensity of CD8⁺ TILs was concordant in only 54.16% of the paired primary lung tumors and BMs. This study showed a high concordance of PD-L1 expression in neoplastic cells between primary NSCLC and synchronous BMs.

Fit-For-Purpose PD-L1 Biomarker Testing For Patient Selection in Immuno-Oncology: Guidelines For Clinical Laboratories From the Canadian Association of Pathologists-Association Canadienne Des Pathologistes (CAP-ACP)

Supplemental Digital Content is available in the text.

Since 2014, programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) checkpoint inhibitors have been approved by various regulatory agencies for the treatment of multiple cancers including melanoma, lung cancer, urothelial carcinoma, renal cell carcinoma, head and neck cancer, classical Hodgkin lymphoma, colorectal cancer, gastroesophageal cancer, hepatocellular cancer, and other solid tumors. Of these approved drug/disease combinations, a subset also has regulatory agency-approved, commercially available companion/complementary diagnostic assays that were clinically validated using data from their corresponding clinical trials. The objective of this document is to provide evidence-based guidance to assist clinical laboratories in establishing fit-for-purpose PD-L1 biomarker assays that can accurately identify patients with specific tumor types who may respond to specific approved immuno-oncology therapies targeting the PD-1/PD-L1 checkpoint. These recommendations are issued as 38 Guideline Statements that address (i) assay development for surgical pathology and cytopathology specimens, (ii) reporting elements, and (iii) quality assurance (including validation/verification, internal quality assurance, and external quality assurance). The intent of this work is to provide recommendations that are relevant to any tumor type, are universally applicable and can be implemented by any clinical immunohistochemistry laboratory performing predictive PD-L1 immunohistochemistry testing.

Frequency of discordance in programmed death-ligand 1 (PD-L1) expression between primary tumors and paired distant metastases in advanced cancers: a systematic review and meta-analysis

Background: To determine the frequency of discordance in programmed death-ligand 1(PD-L1) expression between primary tumors and paired distant metastases in advanced cancers.Methods: We searched MEDLINE and EMBASE for eligible studies and assessed their methodologic quality using QUADAS-2 tool. We estimated the discordant rates (positive to negative or vice versa) of PD-L1 expression in primary tumors and paired distant metastases using logistic-normal random effects model. We performed subgroup analyses based on the PD-L1 status of primary tumors (positive or negative), location of primary tumors (lung or others) and distant metastases (central nervous system or others), timing of distant metastases (synchronous or metachronous), positivity thresholds of PD-L1 expression (1% or 5%) and types of antibody clones used (E1L3N or SP142).Results: Thirteen eligible studies including 451 cases were identified. The included studies were judged to have low to unclear risk of bias. The pooled estimate of discordant rates in PD-L1 expression was 31% (95% CI= 19-47%), with high heterogeneity across the studies (I² = 75%). There was no significant effect modification in the discordant rates according to the predefined subgroups.Conclusion: Approximately one-third of advanced cancer cases have discordance in PD-L1 expression between primary tumors and paired distant metastases. A more liberal testing of PD-L1 expression in both primary and metastatic tumors is recommended in order to identify patients who may benefit from immune checkpoint blockade treatment. Further research exploring the mechanisms and its impact are warranted.

PD-L1 expression correlation with metabolic parameters of FDG PET/CT and clinicopathological characteristics in non-small cell lung cancer

BACKGROUND

Immunotherapy targeting programmed cell death 1 (PD-1) or its ligand 1 (PD-L1) has shown promising results in non-small cell lung cancer (NSCLC) patients. Exploring PD-L1 expression could help to select NSCLC candidates for immunotherapy. Fluorine-18 fluorodeoxyglucose (FDG) PET/CT could provide phenotypic information on malignant tumors. Thus, this study investigated PD-L1 expression correlation with metabolic parameters of FDG PET/CT and clinicopathological characteristics in NSCLC.

METHODS

FDG PET/CT metabolic parameters including maximum standard uptake (SUVmax), metabolic tumor volume and total lesion glycolysis of primary lesion (MTV-P, TLG-P), and combination of primary lesion and metastases (MTV-C, TLG-C) were compared with PD-L1-positive expression in patients with NSCLC. Moreover, clinicopathological characteristics, including age, gender, smoking history, serum tumor markers, tumor location, size, TNM stage, and genetic mutation were also reviewed.

RESULTS

All 374 patients (215 men; 159 women; age 63 ± 9 years) included 283 adenocarcinomas (ACs) and 91 squamous cell carcinomas (SCCs). PD-L1 expression was positive in 27.8% (104/374) cases. SUVmax, TLG-P, and TLG-C of PD-L1 positivity were significantly higher than PD-L1 negativity. Moreover, PD-L1 expression was obviously correlated with man, smoking, and central NSCLC. If ACs and SCCs were separately analyzed, PD-L1 positivity in ACs and SCCs was 21.6% (61/283) and 47.5% (43/91), respectively, and only SUVmax was obviously associated with PD-L1 expression. Furthermore, multivariate analysis revealed that only SUVmax was an independent predictor of PD-L1 positive expression in overall NSCLC, AC, and SCC. Using a SUVmax cut-off value of 12.5, PD-L1 status of NSCLC was predicted by FDG PET/CT with sensitivity, specificity, and accuracy of 65.4%, 86.7%, and 80.7%, respectively.

CONCLUSIONS

PD-L1 expression of NSCLC was related to SUVmax, TLG, man, smoking, and central location. However, only SUVmax was an independent predictor of PD-L1 positivity, which could help to explore the existence of immune checkpoints.

Precision Medicine for NSCLC in the Era of Immunotherapy: New Biomarkers to Select the Most Suitable Treatment or the Most Suitable Patient

In recent years, the evolution of treatments has made it possible to significantly improve the outcomes of patients with non-small cell lung cancer (NSCLC). In particular, while molecular targeted therapies are effective in specific patient sub-groups, immune checkpoint inhibitors (ICIs) have greatly influenced the outcomes of a large proportion of NSCLC patients. While nivolumab activity was initially assessed irrespective of predictive biomarkers, subsequent pivotal studies involving other PD-1/PD-L1 inhibitors in pre-treated advanced NSCLC (atezolizumab within the OAK study and pembrolizumab in the Keynote 010 study) reported the first correlations between clinical outcomes and PD-L1 expression. However, PD-L1 could not be sufficient on its own to select patients who may benefit from immunotherapy. Many studies have tried to discover more precise markers that are derived from tumor tissue or from peripheral blood. This review aims to analyze any characteristics of the immunogram that could be used as a predictive biomarker for response to ICIs. Furthermore, we describe the most important genetic alteration that might predict the activity of immunotherapy.

Prevalence of PD-L1 expression in matched recurrent and/or metastatic sarcoma samples and in a range of selected sarcomas subtypes

We assessed the frequency of programmed death-ligand 1 (PD-L1) expression by immunohistochemistry (IHC) in a cohort of 522 sarcomas from 457 patients, incuding a subset of 46 patients with 63 matched samples from local recurrence or metastases with primary tumours and/or metachronous metastases. We also investigated the correlation of PD-L1 with the presence and degree of tumour-infiltrating lymphocytes (TILs) in a subset of cases. IHC was performed using the PD-L1 SP263 companion kit (VENTANA) on tissue microarrays from an archival cohort. Evaluation of PD-L1 and TILs was performed on full sections for a subset of 23 cases. Fisher’s exact and Mann Whitney test were used to establish significance (P <0.05). PD-L1 positive expression (≥1%) was identified in 31% of undifferentiated pleomorphic sarcomas, 29% of angiosarcomas, 26% of rhabdomyosarcomas, 18% of myxofibrosarcomas, 11% of leiomyosarcomas and 10% of dedifferentiated liposarcomas. Negative expression was present in all atypical lipomatous tumous/well-differentiated lipoasarcomas, myxoid liposarcomas, synovial sarcomas, pleomorphic liposarcomas, and Ewing sarcomas. PD-L1 IHC was concordant in 81% (38 of 47) of matched/paired samples. PD-L1 IHC was discordant in 19% (9 of 47 matched/paired samples), displaying differences in the proportion of cells expressing PD-L1 amongst paired samples with the percentage of PD-L1-positive cells increasing in the metastatic/recurrent site compared to the primary in 6 of 9 cases (67%). Significant correlation between PD-L1 expression and the degree of TILs was exclusively identified in the general cohort of leiomyosarcomas, but not in other sarcoma subtypes or in metastatic/recurrent samples. We conclude that the prevalence of PD-L1 expression in selected sarcomas is variable and likely to be clone dependent. Importantly, we demonstrated that PD-L1 can objectively increase in a small proportion of metastases/recurrent sarcomas, offering the potential of treatment benefit to immune checkpoint inhibitors in this metastatic setting.

Dissociated responses at initial computed tomography evaluation is a good prognostic factor in non-small cell lung cancer patients treated with anti-programmed cell death-1/ligand 1 inhibitors

Background

Dissociated responses (DR) are phenomena in which some tumors shrink, whereas others progress during treatment of patients with cancer. The purpose of the present study was to evaluate the frequency and prognosis of DR in non-small cell lung cancer (NSCLC) patients treated with anti-programmed cell death-1/ligand 1 (anti-PD-1/L1) inhibitors.

Methods

This retrospective study included NSCLC patients who received anti-PD-1/L1 inhibitor as second- or later-line treatment. We excluded patients without radiological evaluation.

In patients who showed progressive disease (PD) according to the RECIST 1.1 at the initial CT evaluation, we evaluated all measurable lesions in each organ to identify DR independently of RECIST 1.1. We defined DR as a disease with some shrinking lesions as well as growing or emerging new lesions. Cases not classified as DR were defined as ‘true PD’. Overall survival was compared between patients with DR and those with true PD using Cox proportional hazards models.

Results

The present study included 62 NSCLC patients aged 27–82 years (median: 65 years). DR and true PD were observed in 11 and 51 patients, respectively. The frequency of DR in NSCLC patients who showed PD to anti-PD-1/L1 was 17.7%. Median overall survival was significantly longer in patients with DR versus true PD (14.0 vs. 6.6 months, respectively; hazard ratio for death: 0.40; 95% confidence interval: 0.17–0.94).

Conclusions

Patients with DR exhibited a relatively favorable prognosis.

Clinical and molecular correlates of PD-L1 expression in patients with lung adenocarcinomas

BACKGROUND

Programmed death-ligand 1 (PD-L1) expression is the only FDA-approved biomarker for immune checkpoint inhibitors (ICIs) in patients with lung adenocarcinoma, but sensitivity is modest. Understanding the impact of molecular phenotype, clinical characteristics, and tumor features on PD-L1 expression is largely unknown and may improve prediction of response to ICI.

PATIENTS AND METHODS

We evaluated patients with lung adenocarcinoma for whom PD-L1 testing and targeted next-generation sequencing (using MSK-IMPACT) was performed on the same tissue sample. Clinical and molecular features were compared across PD-L1 subgroups to examine how molecular phenotype associated with tumor PD-L1 expression. In patients treated with anti-PD-(L)1 blockade, we assessed how these interactions impacted efficacy.

RESULTS

A total of 1586 patients with lung adenocarcinoma had paired PD-L1 testing and targeted next-generation sequencing. PD-L1 negativity was more common in primary compared to metastatic samples (P < 0.001). The distribution of PD-L1 expression (lymph nodes enriched for PD-L1 high; bones predominantly PD-L1 negative) and predictiveness of PD-L1 expression on ICI response varied by organ. Mutations in KRAS, TP53, and MET significantly associated with PD-L1 high expression (each P < 0.001, Q < 0.001) and EGFR and STK11 mutations associated with PD-L1 negativity (P < 0.001, Q = 0.01; P = 0.001, Q < 0.001, respectively). WNT pathway alterations also associated with PD-L1 negativity (P = 0.005). EGFR and STK11 mutants abrogated the predictive value of PD-L1 expression on ICI response.

CONCLUSION

PD-L1 expression and association with ICI response vary across tissue sample sites. Specific molecular features are associated with differential expression of PD-L1 and may impact the predictive capacity of PD-L1 for response to ICIs.

Use of Programmed Death Receptor-1 and/or Programmed Death Ligand 1 Inhibitors for the Treatment of Brain Metastasis of Lung Cancer

The central nervous system (CNS) is regarded as an immune privileged environment; however, changes in the neuroimmunology paradigm have led to an increased interest in systematic immunotherapy in lung cancer therapy. The presence of the lymphatic system in the CNS as well as the physiological and biochemical changes in the blood–brain barrier in the tumor microenvironment suggests that immunocytes are fully capable of entering and exiting the CNS. Emerging clinical data suggest that inhibitors of programmed death receptor-1/programmed death ligand 1 (PD-1/PD-L1) can stimulate surrounding T cells and thus have antitumor effects in the CNS. For example, PD-1 antibody (pembrolizumab) monotherapy has displayed a 20–30% encephalic response rate in patients with brain metastases from malignant melanoma or non-small cell lung cancer. Combined application of nivolumab and ipilimumab anti-PD-1 and anti-cytotoxic T-lymphocyte-associated protein 4 showed an encephalic response rate of 55% in patients with brain metastases of melanoma. Further evidence is required to verify these response rates and identify the mechanisms of curative effects and drug tolerance. While regional treatments such as whole-brain radiosurgery, stereotactic radiosurgery, and brain surgery remain the mainstream, PD-1/PD-L1 inhibitors display potential decreased neurotoxic effects. To date, five drugs have been approved for use in patients with encephalic metastases of lung carcinoma: the anti-PD-1 drugs, pembrolizumab and nivolumab, and the anti-PD-L1 agents, atezolizumab, durvalumab, and avelumab. In recent years, clinical trials of inhibitors in combination with other drugs to treat brain metastasis have also emerged. This review summarizes the biological principles of PD-1/PD-L1 immunotherapy for brain metastasis of lung cancer, as well as ongoing clinical trials to explore unmet needs.

Impact of EGFR-TKI Treatment on the Tumor Immune Microenvironment in EGFR Mutation-Positive Non-Small Cell Lung Cancer

PURPOSE

The impact of EGFR tyrosine kinase inhibitors (TKI) on the tumor immune microenvironment (TME) in non-small cell lung cancer (NSCLC) is unclear.

EXPERIMENTAL DESIGN

We retrospectively identified 138 patients with EGFR-mutated NSCLC who underwent rebiopsy after progression during EGFR-TKI treatment. PD-L1 and CD73 expression in tumor cells and tumor-infiltrating lymphocyte (TIL) density at baseline and after progression were determined by IHC. Tumor mutation burden (TMB) was determined by next-generation sequencing.

RESULTS

The proportion of patients with a PD-L1 expression level of ≥50% (high) increased from 14% before to 28% after EGFR-TKI (P = 0.0010). Whereas CD8⁺ and FOXP3⁺ TIL densities were significantly lower after EGFR-TKI treatment than before, CD8⁺ TIL density was maintained in tumors with a high PD-L1 expression level. Expression of CD73 in tumor cells after EGFR-TKI treatment was higher than that before in patients with a high PD-L1 expression level. TMB tended to be higher after EGFR-TKI treatment than before (3.3→4.1 mutations/Mbp, P = 0.0508). Median progression-free survival for subsequent treatment with antibodies to PD-1 was longer for patients with a high than for those with a low PD-L1 expression after EGFR-TKI (7.1 vs. 1.7 months, P = 0.0033), and two of five patients whose PD-L1 expression level changed from low to high after EGFR-TKI treatment achieved a PFS of >6 months.

CONCLUSIONS

EGFR-TKI treatment was associated with changes in the TME of EGFR-mutated NSCLC, and such changes may provide clues for optimization of subsequent PD-1 inhibitor treatment.