Differential Expression of PD-L1 between Primary and Metastatic Sites in Clear-Cell Renal Cell Carcinoma

Discrepancy in PD-L1 expression between primary and metastatic tumors in two patients with recurrent cervical cancer

Introduction

Pembrolizumab is an immunotherapy approved for use in patients with a combined positive score (CPS) greater than one with recurrent cervical cancer. In clinical practice, the CPS score is not typically analyzed in both primary and metastatic specimens.

Case descriptions

Case 1A 42-year-old woman with history of an abnormal pap smears who presented with a large pelvic mass with initial biopsy of cervix demonstrating squamous cell carcinoma with negative PDL1 expression and a CPS score of 0. She underwent chemoradiation and presented three months after primary treatment completion with recurrence of squamous cell carcinoma and positive PD-L1 expression with a CPS score of 20. Pembrolizumab was added to cycle three of her systemic chemotherapy regimen of carboplatin/paclitaxel/bevacizumab. She had progression on this regimen and was transitioned to tisotumab vedotin; however, ultimately opted to proceed with hospice secondary to failure to thrive.Case 2A 36-year-old woman with history of an abnormal pap smear in pregnancy and initial biopsy demonstrating endocervical adenocarcinoma, mucinous type. She underwent open radical hysterectomy, bilateral salpingectomy, bilateral oophorepexy, and bilateral pelvic lymph node dissection with subsequent adjuvant chemoradiation. Her initial pathology demonstrated positive PDL1 expression with CPS score of 15. She presented six months after completion of primary treatment with recurrence of endocervical adenocarcinoma, mucinous type and negative PD-L1 expression with a CPS score of < 1. Regardless of this discrepancy, pembrolizumab was added to cycle five of her systemic chemotherapy regimen of carboplatin/paclitaxel/bevacizumab. She initially demonstrated a mixed response; however, ultimately progressed after eight cycles and was transitioned to tisotumab vedotin.

Discussion

To our knowledge, discrepancies in PD-L1 expression in a matched setting between primary and metastatic tumors has only been reported once. This is the first case report describing these inconsistencies. Etiologies of and outcomes related to the discrepant expression of PD-L1 should be further studied.

Trop-2 expression and the tumor immune microenvironment in cervical cancer

OBJECTIVE

Trophoblast Cell Surface Antigen 2 (Trop-2) is a transmembrane glycoprotein that is overexpressed in various cancers, with immunological significance as a target for tumor-reactive T-cells. We aimed to investigate the association between the expression of Trop-2 and the tumor immune microenvironment in cervical cancer.

METHODS

The study included 123 patients with cervical cancer who underwent primary surgery between 2000 and 2020 in our hospital. Trop-2 expression was evaluated using anti-Trop-2 monoclonal antibody clone MAB650. Immune biomarkers, including PD-L1 (22C3), CD3 (PS1), and CD8 (4B11), were also evaluated. Trop-2 and PD-L1 positivity were defined by an H-score ≥ 10 and a combined positive score (CPS) ≥1, respectively. Tumor-infiltrating lymphocytes (TILs) were assessed in the five selected independent areas. The correlation between Trop-2 expression and immune biomarkers was analyzed.

RESULTS

The cohort comprised patients with squamous cell carcinoma (SCC) (54.5%) and non-SCC (45.5%). Trop-2 was positive in 84.6% of samples and more commonly expressed in SCC (SCC vs. non-SCC; 97.0% vs. 69.6%, p < 0.001). Intratumoral CD3+ and CD8 + TILs were significantly more common in Trop-2-positive cases (CD3, Mann-Whitney U = 383, p < 0.0001; CD8, U = 442, p < 0.0001). Additionally, significant positive correlations were found between the Trop-2 H-score and immune markers (CD3 + TILs, r = 0.295, p < 0.001; CD8 + TILs, r = 0.267, p = 0.001; PD-L1 CPS, r = 0.178, p = 0.025). No significant associations were detected between TILs and other clinicopathological features, including prognosis.

CONCLUSION

Expression of Trop-2 in cervical cancer is associated with increased levels of intratumoral TILs, indicating the potential of Trop-2 targeted therapy alone or in combination with immune checkpoint inhibitors.

PD1/PD-L1 blockade in clear cell renal cell carcinoma: mechanistic insights, clinical efficacy, and future perspectives

The advent of PD1/PD-L1 inhibitors has significantly transformed the therapeutic landscape for clear cell renal cell carcinoma (ccRCC). This review provides an in-depth analysis of the biological functions and regulatory mechanisms of PD1 and PD-L1 in ccRCC, emphasizing their role in tumor immune evasion. We comprehensively evaluate the clinical efficacy and safety profiles of PD1/PD-L1 inhibitors, such as Nivolumab and Pembrolizumab, through a critical examination of recent clinical trial data. Furthermore, we discuss the challenges posed by resistance mechanisms to these therapies and potential strategies to overcome them. We also explores the synergistic potential of combination therapies, integrating PD1/PD-L1 inhibitors with other immunotherapies, targeted therapies, and conventional modalities such as chemotherapy and radiotherapy. In addition, we examine emerging predictive biomarkers for response to PD1/PD-L1 blockade and biomarkers indicative of resistance, providing a foundation for personalized therapeutic approaches. Finally, we outline future research directions, highlighting the need for novel therapeutic strategies, deeper mechanistic insights, and the development of individualized treatment regimens. Our work summarizes the latest knowledge and progress in this field, aiming to provide a valuable reference for improving clinical efficacy and guiding future research on the application of PD1/PD-L1 inhibitors in ccRCC.

Immunotherapy and radiotherapy for older patients with invasive bladder cancer unfit for surgery or chemotherapy: practical proposal by the international geriatric radiotherapy group

The standard of care for non-metastatic muscle invasive bladder cancer is either radical cystectomy or bladder preservation therapy, which consists of maximal transurethral bladder resection of the tumor followed by concurrent chemoradiation with a cisplatin-based regimen. However, for older cancer patients who are too frail for surgical resection or have decreased renal function, radiotherapy alone may offer palliation. Recently, immunotherapy with immune checkpoint inhibitors (ICI) has emerged as a promising treatment when combined with radiotherapy due to the synergy of those two modalities. Transitional carcinoma of the bladder is traditionally a model for immunotherapy with an excellent response to Bacille Calmette-Guerin (BCG) in early disease stages, and with avelumab and atezolizumab for metastatic disease. Thus, we propose an algorithm combining immunotherapy and radiotherapy for older patients with locally advanced muscle-invasive bladder cancer who are not candidates for cisplatin-based chemotherapy and surgery.

Neopterin as a potential prognostic and predictive biomarker in metastatic renal cell carcinoma treated with immune checkpoint inhibitors

INTRODUCTION

Immunotherapy represents a significant and essential component of renal carcinoma therapy (RCC), but the selection of an optimal regimen for an individual patient remains unclear. Despite significant improvements in therapeutic options for RCC, predictive biomarkers for immunotherapeutic agents remain elusive. Neopterin is a biomarker of cell-mediated immune response, with concentrations increased in different disorders, including cancer. High neopterin levels herald, in general, a poor prognosis.

AREAS COVERED

This review briefly overviews the contemporary clinical data on biomarkers in metastatic RCC therapy, focusing on neopterin.

EXPERT OPINION

Elevated neopterin levels have been observed in tumors of different primary locations. Research indicates that neopterin may serve as a potential biomarker for assessing the inflammatory status associated with certain cancers. However, it is necessary to interpret neopterin levels in the context of a comprehensive clinical evaluation, as elevated neopterin alone is not specific to cancer and can be influenced by other factors, including comorbid conditions. Neopterin has also been identified as a prognostic biomarker. An increasing neopterin level in serum and urine is associated with advanced cancer, but the role as a potential predictor of response to immunotherapy has yet to be established. A reliable biomarker for optimal therapy selection in metastatic RCC is still putative.

The Evolving Landscape of Biomarkers for Immune Checkpoint Blockade in Genitourinary Cancers

In the past decade, immune checkpoint inhibitors (ICI) have been approved for treatment of genitourinary malignancies and have revolutionized the treatment landscape of these tumors. However, despite the remarkable success of these therapies in some GU malignancies, many patients' tumors do not respond to these therapies, and others may experience significant side effects, such as immune-related adverse events (iRAEs). Accordingly, biomarkers and improved prognostic tools are critically needed to help predict which patients will respond to ICI, predict and mitigate risk of developing immune-related adverse events, and inform personalized choice of therapy for each patient. Ongoing clinical and preclinical studies continue to provide an increasingly robust understanding of the mechanisms of the response to immunotherapy, which continue to inform biomarker development and validation. Herein, we provide a comprehensive review of biomarkers of the response to immunotherapy in GU tumors and their role in selection of therapy and disease monitoring.

Molecular analysis of primary and metastatic sites in patients with renal cell carcinoma

BACKGROUNDMetastases are the hallmark of lethal cancer, though underlying mechanisms that drive metastatic spread to specific organs remain poorly understood. Renal cell carcinoma (RCC) is known to have distinct sites of metastases, with lung, bone, liver, and lymph nodes being more common than brain, gastrointestinal tract, and endocrine glands. Previous studies have shown varying clinical behavior and prognosis associated with the site of metastatic spread; however, little is known about the molecular underpinnings that contribute to the differential outcomes observed by the site of metastasis.METHODSWe analyzed primary renal tumors and tumors derived from metastatic sites to comprehensively characterize genomic and transcriptomic features of tumor cells as well as to evaluate the tumor microenvironment at both sites.RESULTSWe included a total of 657 tumor samples (340 from the primary site [kidney] and 317 from various sites of metastasis). We show distinct genomic alterations, transcriptomic signatures, and immune and stromal tumor microenvironments across metastatic sites in a large cohort of patients with RCC.CONCLUSIONWe demonstrate significant heterogeneity among primary tumors and metastatic sites and elucidate the complex interplay between tumor cells and the extrinsic tumor microenvironment that is vital for developing effective anticancer therapies.

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.

The Vanishing Clinical Value of PD-L1 Status as a Predictive Biomarker in the First-Line Treatment of Urothelial Carcinoma of the Bladder

BACKGROUND

Our study endeavors to elucidate the clinical implications of PD-L1 positivity in individuals afflicted with advanced urothelial carcinoma of the bladder (UCB).

METHODS

Patients with advanced UCB were prospectively enrolled following a radical cystectomy (RC) performed within January 2017 to December 2022 at our tertiary referral center. The clinical outcome, defined as the progression-free survival (PFS) and overall survival (OS) on systemic treatment, was analyzed using an χ2-test, Mann-Whitney U-test, the Kaplan-Meier method, and a log-rank test.

RESULTS

A total of 648 patients were included following an RC performed within January 2017 to December 2022. Their PD-L1 status was analyzed with the primary PD-L1-specific antibody (clone SP263, Ventana) and defined both by the CPS and IC-score in 282 patients (43.5%) with a high risk (pT3-pT4 and/or lymph node involvement) or metastatic UCB. While the median PFS was significantly prolonged 5-fold in PD-L1+ patients, we found no difference in OS, regardless of PD-L1 status, or treatment regimen.

CONCLUSIONS

While PD-L1 positivity indicates prolonged PFS, the presence of PD-L1 does not influence OS rates, suggesting its limited usefulness as a prognostic biomarker in bladder cancer. However, the positive correlation between an PD-L1 status and a sustained response to ICI treatments indicates its potential role as a predictive biomarker. Further research is required to understand how the predictive value of PD-L1 positivity may extend to the use of ICIs in combination with antibody-drug conjugates.

Established and emerging biomarkers of immunotherapy in renal cell carcinoma

Immunotherapies, such as immune checkpoint inhibitors, have heralded impressive progress for patient care in renal cell carcinoma (RCC). Despite this success, some patients' disease fails to respond, and other patients experience significant side effects. Thus, development of biomarkers is needed to ensure that patients can be selected to maximize benefit from immunotherapies. Improving clinicians' ability to predict which patients will respond to immunotherapy and which are most at risk of adverse events - namely through clinical biomarkers - is indispensable for patient safety and therapeutic efficacy. Accordingly, an evolving suite of therapeutic biomarkers continues to be investigated. This review discusses biomarkers for immunotherapy in RCC, highlighting current practices and emerging innovations, aiming to contribute to improved outcomes for patients with RCC.

PD-1 Expression on Intratumoral Regulatory T Cells Is Associated with Lack of Benefit from Anti-PD-1 Therapy in Metastatic Clear-Cell Renal Cell Carcinoma Patients

PURPOSE

Programmed cell death protein 1 (PD-1) expression on CD8+TIM-3-LAG-3- tumor-infiltrating cells predicts positive response to PD-1 blockade in metastatic clear-cell renal cell carcinoma (mccRCC). Because inhibition of PD-1 signaling in regulatory T cells (Treg) augments their immunosuppressive function, we hypothesized that PD-1 expression on tumor-infiltrating Tregs would predict resistance to PD-1 inhibitors.

EXPERIMENTAL DESIGN

PD-1+ Tregs were phenotyped using multiparametric immunofluorescence in ccRCC tissues from the CheckMate-025 trial (nivolumab: n = 91; everolimus: n = 90). Expression of CD8, PD-1, TIM-3, and LAG-3 was previously determined (Ficial and colleagues, 2021). Clinical endpoints included progression-free survival (PFS), overall survival (OS), and objective response rate (ORR).

RESULTS

In the nivolumab (but not everolimus) arm, high percentage of PD-1+ Tregs was associated with shorter PFS (3.19 vs. 5.78 months; P = 0.021), shorter OS (18.1 vs. 27.7 months; P = 0.013) and marginally lower ORR (12.5% vs. 31.3%; P = 0.059). An integrated biomarker (PD-1 Treg/CD8 ratio) was developed by calculating the ratio between percentage of PD-1+Tregs (marker of resistance) and percentage of CD8+PD-1+TIM-3-LAG-3- cells (marker of response). In the nivolumab (but not everolimus) arm, patients with high PD-1 Treg/CD8 ratio experienced shorter PFS (3.48 vs. 9.23 months; P < 0.001), shorter OS (18.14 vs. 38.21 months; P < 0.001), and lower ORR (15.69% vs. 40.00%; P = 0.009). Compared with the individual biomarkers, the PD-1 Treg/CD8 ratio showed improved ability to predict outcomes to nivolumab versus everolimus.

CONCLUSIONS

PD-1 expression on Tregs is associated with resistance to PD-1 blockade in mccRCC, suggesting that targeting Tregs may synergize with PD-1 inhibition. A model that integrates PD-1 expression on Tregs and CD8+TIM-3-LAG-3- cells has higher predictive value.

Refining PD-1/PD-L1 assessment for biomarker-guided immunotherapy: A review

Anti-programmed cell death ligand 1 (anti-PD-L1)  immunotherapy is an increasingly crucial in cancer treatment. To date, the Federal Drug Administration (FDA) has approved four PD-L1 immunohistochemistry (IHC) staining protocols, commercially available in the form of "kits", facilitating testing for PD-L1 expression. These kits comprise four PD-L1 antibodies on two separate IHC platforms, each utilizing distinct, non-interchangeable scoring systems. Several factors, including tumor heterogeneity and the size of the tissue specimens assessed, can lead to PD-L1 status misclassification, potentially hindering the initiation of therapy. Therefore, the development of more accurate predictive biomarkers to distinguish between responders and non-responders prior to anti-PD-1/PD-L1 therapy warrants further research. Achieving this goal necessitates refining sampling criteria, enhancing current methods of PD-L1 detection, and deepening our understanding of the impact of additional biomarkers. In this article, we review potential solutions to improve the predictive accuracy of PD-L1 assessment in order to more precisely anticipate patients' responses to anti-PD-1/PD-L1 therapy, monitor disease progression and predict clinical outcomes.

Comparison of PD-L1 expression and MMR status between primary and matched metastatic lesions in patients with cervical cancer

PURPOSE

Programmed death-ligand 1 (PD-L1) and DNA mismatch repair (MMR) are considered predictive biomarkers for immunotherapy in cervical cancer. However, their expression in primary tumors and metastases does not always match affecting the course of treatment. We investigated the consistency of their expression in primary and matched recurrent/metastatic lesions from patients with cervical cancer.

METHODS

Primary and matched recurrent/metastatic specimens from patients with recurrent cervical cancer (n = 194) were stained for PD-L1 and MMR (MLHI, MSH6, MSH2, and PMS2) using immunohistochemistry. The degree of consistency of PD-L1 and MMR expression in these lesions was analyzed.

RESULTS

The inconsistency rate of PD-L1 expression in primary and recurrent/metastatic lesions was 33.0%, and it varied between the recurrence sites. Positive PD-L1 rate in primary lesions was lower (15.4%) than that in recurrent/metastatic lesions (30.4%). The discordance rate of MMR expression between primary and recurrent/metastatic lesions was 4.1%.

CONCLUSION

We conclude that to use PD-L1 as a predictive biomarker for immunotherapy, analysis of both metastatic and primary lesions may be required. High consistency rate of MMR expression between primary and metastatic lesions suggests that testing primary lesions alone can be sufficient for guiding the course of therapy, thereby solving the difficulty of obtaining recurrent/metastatic specimens in clinic.

A robust gene prognostic index composed of GZMB, IRF1, and TP63 can stratify the risk of two metastatic urothelial carcinoma cohorts based on immune checkpoint blockade therapy

BACKGROUND

Immune checkpoint blockade (ICB) therapy has become a first-line treatment option for metastatic urothelial carcinoma (mUC) patients who do not meet the criteria of cisplatin. Still, only a few people can benefit from it, so useful predictive markers are needed.

METHODS

Download the ICB-based mUC and chemotherapy-based bladder cancer cohorts, and extract the expression data of pyroptosis-related genes (PRG). The LASSO algorithm was used to construct the PRG prognostic index (PRGPI) in the mUC cohort, and we verified the prognostic ability of PRGPI in two mUC and two bladder cancer cohorts.

RESULTS

Most of the PRG in the mUC cohort were immune-activated genes, and a few were immunosuppressive genes. The PRGPI composed of GZMB, IRF1, and TP63 can stratify the risk of mUC. In IMvigor210 and GSE176307 cohorts, the P-values of Kaplan Meier analysis was < 0.01 and 0.002, respectively. PRGPI could also predict ICB response, and the chi-square test of the two cohorts had P-values of 0.002 and 0.046, respectively. In addition, PRGPI can also predict the prognosis of two bladder cancer cohorts without ICB therapy. The PRGPI and the expression of PDCD1/CD274 had a high degree of synergistic correlation. The Low PRGPI group showed prominent characteristics of immune infiltration and was enriched in the immune signal activation pathway.

CONCLUSION

The PRGPI we constructed can effectively predict the treatment response and overall survival rate of mUC patients treated with ICB. The PRGPI can help mUC patients achieve individualized and accurate treatment in the future.

Current Landscape of Genomic Biomarkers in Clear Cell Renal Cell Carcinoma

CONTEXT

Dramatic gains in our understanding of the molecular biology of clear cell renal cell carcinoma (ccRCC) have created a foundation for clinical translation to improve patient care.

OBJECTIVE

To review and contextualize clinically impactful data surrounding genomic biomarkers in ccRCC.

EVIDENCE ACQUISITION

A systematic literature search was conducted focusing on genomic-based biomarkers with an emphasis on studies assessing clinical outcomes.

EVIDENCE SYNTHESIS

The advancement of tumor sequencing techniques has led to a rapid increase in the knowledge of the molecular underpinnings of ccRCC and with that the discovery of multiple candidate genomic biomarkers. These include somatic gene mutations such as VHL, PBRM1, SETD2, and BAP1; copy number variations; transcriptomic multigene signatures; and specific immune cell populations. Many of these biomarkers have been assessed for their association with survival and a smaller number as potential predictors of a response to systemic therapy. In this scoping review, we discuss many of these biomarkers in detail. Further studies are needed to continue to refine and validate these molecular tools for risk stratification, with the ultimate goal of improving clinical decision-making and patient outcomes.

CONCLUSIONS

While no tissue or blood-based biomarkers for ccRCC have been incorporated into routine clinical practice to date, the field continues to expand rapidly. There remains a critical need to develop and validate these tools in order to improve the care for patients with kidney cancer.

PATIENT SUMMARY

Genomic biomarkers have the potential to better predict outcome and select the most appropriate treatment for patients with kidney cancer; however, further research is needed before any of these currently developed biomarkers are adopted into clinical practice.

Phase II trial of neoadjuvant sitravatinib plus nivolumab in patients undergoing nephrectomy for locally advanced clear cell renal cell carcinoma

Sitravatinib is an immunomodulatory tyrosine kinase inhibitor that can augment responses when combined with programmed death-1 inhibitors such as nivolumab. We report a single-arm, interventional, phase 2 study of neoadjuvant sitravatinib in combination with nivolumab in patients with locally advanced clear cell renal cell carcinoma (ccRCC) prior to curative nephrectomy (NCT03680521). The primary endpoint was objective response rate (ORR) prior to surgery with a null hypothesis ORR = 5% and the alternative hypothesis set at ORR = 30%. Secondary endpoints were safety; pharmacokinetics (PK) of sitravatinib; immune effects, including changes in programmed cell death-ligand 1 expression; time-to-surgery; and disease-free survival (DFS). Twenty patients were evaluable for safety and 17 for efficacy. The ORR was 11.8%, and 24-month DFS probability was 88·0% (95% CI 61.0 to 97.0). There were no grade 4/5 treatment-related adverse events. Sitravatinib PK did not change following the addition of nivolumab. Correlative blood and tissue analyses showed changes in the tumour microenvironment resulting in an immunologically active tumour by the time of surgery (median time-to-surgery: 50 days). The primary endpoint of this study was not met as short-term neoadjuvant sitravatinib and nivolumab did not substantially increase ORR.

Biomarkers for Early Detection, Prognosis, and Therapeutics of Esophageal Cancers

Esophageal cancer (EC) is the deadliest cancer worldwide, with a 92% annual mortality rate per incidence. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two major types of ECs, with EAC having one of the worst prognoses in oncology. Limited screening techniques and a lack of molecular analysis of diseased tissues have led to late-stage presentation and very low survival durations. The five-year survival rate of EC is less than 20%. Thus, early diagnosis of EC may prolong survival and improve clinical outcomes. Cellular and molecular biomarkers are used for diagnosis. At present, esophageal biopsy during upper endoscopy and histopathological analysis is the standard screening modality for both ESCC and EAC. However, this is an invasive method that fails to yield a molecular profile of the diseased compartment. To decrease the invasiveness of the procedures for diagnosis, researchers are proposing non-invasive biomarkers for early diagnosis and point-of-care screening options. Liquid biopsy involves the collection of body fluids (blood, urine, and saliva) non-invasively or with minimal invasiveness. In this review, we have critically discussed various biomarkers and specimen retrieval techniques for ESCC and EAC.

Heterogeneity of PD-L1 expression and CD8 lymphocyte infiltration in metastatic colorectal cancer and their prognostic significance

Purpose

In recent years, immune checkpoint inhibitors have become a major therapeutic method for the treatment of metastatic colorectal cancer (mCRC). Growing evidence indicates that tumour-infiltrating lymphocytes (TILs) in the tumour microenvironment are a prerequisite for the effectiveness of PD-1/PD-L1 blockade therapy. In this study, we aimed to compare PD-L1 expression and cluster of differentiation 4 (CD4) and CD8 TIL infiltration in primary tumours and paired metastases.

Patients and methods

Altogether, 111 patients with mCRC who underwent surgery at our hospital were included. PD-L1, CD4, and CD8 expression were detected by immunohistochemistry in a tissue microarray. PD-L1 expression was assessed using the combined positivity score (CPS), and a score ≥1 was judged as positive. The area proportion of TILs with positive staining ≥10% was classified as "high", while <10% was classified as "low".

Results

We observed the discordance of PD-L1 expression between primary tumours and paired metastases in 35/111 (31.5%) patients (κ = 0.137, P = 0.142). This heterogeneity was significantly correlated with discordance of CD8 TIL infiltration between primary tumours and paired metastases (P = 0.003). Compared with corresponding colorectal cancer tumours, lung metastases showed more CD8 TIL infiltration (P = 0.022, median: 8.5% vs. 5.0%), whereas liver metastases exhibited less CD8 TIL infiltration (P = 0.028, median: 3.0% vs. 5.0%). Area proportion of CD4⁺ and CD8⁺ TIL infiltration in lung metastases were all higher than those in liver metastases (P = 0.005, median: 15.0% vs. 9.0%; P = 0.001, median: 8.5% vs. 3.0%). Compared with p MMR (MSI-L/MS-S) subgroup, area proportion of CD8 TIL infiltration in primary tumours and CD4, CD8 TIL infiltration in paired metastases were all higher in d MMR (MSI-H) group (P = 0.026, median: 15.0% vs 5.0%; P = 0.039, median: 15.0% vs 9.0%; P = 0.015, median: 15.0% vs 5.0%). Preoperative chemo/radiotherapy may increase CD8 TIL infiltration in primary tumours (P = 0.045, median: 10.0% vs. 5.0%). CD8 TIL infiltration in primary tumours was an independent predictive factor for overall survival (HR 0.28, 95% CI 0.09-0.93, P = 0.038).

Conclusion

Heterogeneity in PD-L1 expression and CD8 TIL infiltration was found between primary tumours and paired metastases in mCRC. CD8 TIL infiltration in primary tumours could independently forecast the overall survival of patients with mCRC.

Expression of Programmed Death-1 Ligand in Renal Cell Carcinoma and Its Relationship with Pathologic Findings and Disease-Free Survival

Background: Renal cell carcinoma (RCC) is an invasive malignancy of kidney origin. The programmed death-1 ligand (PD-L1) with its receptor (PD-1) on T-cells can inactivate antitumor response and possibly lead to poor outcomes in patients with RCC. Methods: Our study assessed the expression of PD-L1 by immunohistochemical staining on 86 radical or partial nephrectomy samples with RCC diagnoses with diverse types, tumor grades, and stages. Tumor specimens were collected from the pathology archive of 2014 - 2017 in Sina Hospital, Tehran, Iran. Results: Out of 86 studied RCC samples, 68 cases (79.1%) were clear cell types. PD-L1 expression was observed more in non-clear cell carcinoma samples than in clear cell carcinoma (P = 0.008). PD-L1 expression had significant relationships with nuclear grade and tumor necrosis (P = 0.025 and 0.010, respectively). However, PD-L1 expression was not correlated with tumor size, lymphovascular invasion, and sarcomatoid differentiation. The disease-free survival rate in patients with PD-L1 expression was significantly less than in patients with PD-L1 negative staining (P = 0.032). Conclusions: According to our findings, PD-L1 could be regarded as an important biomarker with worse prognosis and aggressive clinicopathologic findings in patients with RCC.

Transcriptomic Correlates of Tumor Cell PD-L1 Expression and Response to Nivolumab Monotherapy in Metastatic Clear Cell Renal Cell Carcinoma

PURPOSE

PD-L1 expression on tumor cells (TC) is associated with response to anti-PD-1-based therapies in some tumor types, but its significance in clear cell renal cell carcinoma (ccRCC) is uncertain. We leveraged tumor heterogeneity to identify molecular correlates of TC PD-L1 expression in ccRCC and assessed their role in predicting response to anti-PD-1 monotherapy.

EXPERIMENTAL DESIGN

RNA sequencing was performed on paired TC PD-L1 positive and negative areas isolated from eight ccRCC tumors and transcriptomic features associated with PD-L1 status were identified. A cohort of 232 patients with metastatic ccRCC from the randomized CheckMate-025 (CM-025) trial was used to confirm the findings and correlate transcriptomic profiles with clinical outcomes.

RESULTS

In both the paired samples and the CM-025 cohort, TC PD-L1 expression was associated with combined overexpression of immune- and cell proliferation-related pathways, upregulation of T-cell activation signatures, and increased tumor-infiltrating immune cells. In the CM-025 cohort, TC PD-L1 expression was not associated with clinical outcomes. A molecular RCC subtype characterized by combined overexpression of immune- and cell proliferation-related pathways (previously defined by unsupervised clustering of transcriptomic data) was enriched in TC PD-L1 positive tumors and displayed longer progression-free survival (HR, 0.32; 95% confidence interval, 0.13-0.83) and higher objective response rate (30% vs. 0%, P = 0.04) on nivolumab compared with everolimus.

CONCLUSIONS

Both TC-extrinsic (immune-related) and TC-intrinsic (cell proliferation-related) mechanisms are likely intertwined in the regulation of TC PD-L1 expression in ccRCC. The quantitation of these transcriptional programs may better predict benefit from anti-PD-1-based therapy compared with TC PD-L1 expression alone in ccRCC.

Identification of immune subtypes to guide immunotherapy and targeted therapy in clear cell renal cell carcinoma

Accumulating pieces of evidence suggested that immunotypes may indicate the overall immune landscape in the tumor microenvironment, which were closely related to therapeutic response. The purpose of this study was to classify and define the immune subtypes of clear cell renal cell carcinoma (ccRCC), so as to authenticate the potential immune subtypes that respond to immunotherapy. Transcriptome expression profile and mutation profile data of ccRCC, as well as clinical characteristics used in this study were obtained from TCGA database. There were significant differences in the infiltration of immune cells, immune checkpoints, and antigens between ccRCC and para-cancerous tissues. According to immune components, patients with ccRCC were divided into three immune subtypes, with different clinical and molecular characteristics. Compared with other subtypes, IS2 showed cold immune phenotype, and was associated with better survival. IS1 represented complex immune populations and was associated with poor overall survival (OS) and progression free survival (PFS). Further analysis indicated that expression of immune checkpoints also differed among the three subtypes, and was abnormally up-regulated in IS3. Pathway enrichment analysis indicated that the mTOR signaling pathway was abnormally enriched in IS3, while the TGF_BETA, ANGIOGENESIS and receptor tyrosine kinase signaling pathways were abnormally enriched in IS2. Furthermore, there was an abnormal enrichment of the epithelial-to-mesenchymal transition (EMT) signaling pathway in IS1, which may be associated with a higher rate of metastasis. Finally, SCG2 was screened as a specific antigen of ccRCC, which was not only related to poor prognosis, but also significantly associated with immune cells and immune checkpoints. In conclusion, the immune subtypes of ccRCC may provide new insights into the tumor biology and the precise clinical management of this disease.

Prognostic value of tumor immune biomarkers in biopsies from patients with refractory solid cancers

PD-L1 and tumor-infiltrating lymphocytes play a key role in the immune escape of cancer, although their prognostic value remains unknown in patients with refractory solid cancer compared to other known prognostic estimation methods. In this ancillary study, we assessed the prognostic value of previously-defined prognostic scores (such as the Royal Marsden Hospital (RMH) score) and of PD-L1, CD3, CD8 and FOXP3 expressions based on immunohistochemistry (IHC) and RNA sequencing (RNAseq) of tumor samples from patients included in the personalized-medicine MOSCATO-02 trial. We collected biopsies with successful IHC analysis from 266 patients treated between April 2016 and September 2017, among whom 170 (63.9%) also had a matched RNAseq. We used a Random Forest model to identify the best prognostic factor, and a Lasso-penalized Cox model to validate the findings. We found that the RMH score was the strongest prognostic factor, with high scores associated with a higher risk of death (Hazard Ratio (HR)=1.29; CI95%[1.19-1.21]). The PD-L1 expression score obtained from IHC analyses was the second-best performing predictor, with the 1+ score (low expression) linked to a lower risk of death (HR=0.564; CI95%[0.539-0.580]). Other tested variables, including primary tumor type and subsequent treatments received following biopsy, were not found significantly linked to prognosis. We found modest correlation between IHC and RNAseq expressions of immune genes, but RNAseq related better to prognosis. Overall, our study supports the use of the RMH score and the assessment of PD-L1 expression in IHC to estimate prognosis in patients with advanced cancer.

Immune checkpoint inhibitor-based therapy for advanced clear cell renal cell carcinoma: A narrative review

The prognosis for advanced clear cell renal cell carcinoma (ccRCC) is not satisfactory, even though its treatment has evolved rapidly over the past 20 years. Systemic ccRCC treatment options mainly involve antiangiogenic therapy, immune checkpoint blockade, or a combination of these therapies, and as more clinical evidence becomes available, immune checkpoint inhibitors (ICIs) are increasingly dominant. Conventional ICIs lead to the restoration of T-cell activation and a reduction in T-cell depletion by specifically blocking programmed cell death 1 (PD-1), programmed cell death 1 ligand 1 (PD-L1) or cytotoxic T lymphocyte antigen 4 (CTLA-4), ultimately enhancing the antitumor immune response. There is no doubt that these therapies have achieved some clinical efficacy in the overall ccRCC population, but response rates and durability remain a great challenge. Therefore, novel immune checkpoints or new combination therapeutic strategies based on ICIs continue to be sought and developed. This review will provide a comprehensive overview of ICI-based therapeutic strategies in advanced ccRCC, including their mechanisms of action and the latest clinical evidence.

Adjuvant therapy for patients with renal cell carcinoma following surgery: a focus on pembrolizumab

INTRODUCTION

Many patients with renal cell carcinoma (RCC) who undergo surgery with curative intent have a high risk of disease recurrence and until recently no palatable adjuvant systemic therapy options. Blocking the programmed death ligand (PD-1) immune checkpoint pathway with pembrolizumab has robust clinical efficacy in patients with metastatic RCC. Results from the KEYNOTE 564 trial demonstrate that adjuvant pembrolizumab significantly improves disease- free survival after nephrectomy or metastatectomy.

AREAS COVERED

We provide an overview of efforts to develop an adjuvant therapy in patients with high-risk RCC. This includes a critical review of efficacy, toxicity, and clinical implications from a large phase III trial leading to the FDA and EMA approvals of adjuvant pembrolizumab.

EXPERT OPINION

Pembrolizumab offers an effective and well-tolerated adjuvant therapy for patients with surgically resected RCC at high-risk of disease recurrence. Future research will focus on optimal patient selection and biomarkers that predict benefit and/or toxicity from therapy.

Near-Infrared Responsive Membrane Nanovesicles Amplify Homologous Targeting Delivery of Anti-PD Immunotherapy against Metastatic Tumors

The major obstacles of anti-PD therapy in metastatic tumors are limited drug delivery in primary tumors and metastatic foci, and the lack of tumor-infiltrating lymphocytes (TILs). Here, the authors constructed a novel cellular membrane nanovesicles platform (M/IR NPs) based on homologous targeting and near-infrared (NIR) responsive release strategy to potentiate PD-1/PD-L1 blockade therapy against metastatic tumors. In tumor-bearing mice, biomimetic M/IR NPs targeted both primary tumors and their lung metastases. Upon laser irradiation, M/IR NPs reduced cancer-associated fibroblasts (CAFs) in tumor microenvironment, thus increasing the penetration of TILs. When shed from homologous tumor cell membranes, positively charged nanoparticles (IR NPs) core can capture released tumor-associated antigens, thereby enhancing the antigen-presenting ability of DCs to activate cytotoxic T lymphocytes. When the photothermal conversion temperature under NIR-laser is higher than 42 °C, M/IR NPs initiated the rupture of cell membranes and the responsive release of PD-1/PD-L1 inhibitor BMS, which significantly attenuated tumor-associated immunosuppression and synergistically induced T cellular immunity to inhibit the tumor growth and metastasis. Overall, biomimetic M/IR NPs can improve the targeting and therapeutic efficacy of anti-PD therapy in primary tumors and metastases, opening up a new avenue for the diagnosis and treatment of metastatic tumors in the future.

Biomarkers of response to PD-1 pathway blockade

The binding of T cell immune checkpoint proteins programmed death 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) to their ligands allows immune evasion by tumours. The development of therapeutic antibodies, termed checkpoint inhibitors, that bind these molecules or their ligands, has provided a means to release this brake on the host anti-tumour immune response. However, these drugs are costly, are associated with potentially severe side effects, and only benefit a small subset of patients. It is therefore important to identify biomarkers that discriminate between responders and non-responders. This review discusses the determinants for a successful response to antibodies that bind PD-1 or its ligand PD-L1, dividing them into markers found in the tumour biopsy and those in non-tumour samples. It provides an update on the established predictive biomarkers (tumour PD-L1 expression, tumour mismatch repair deficiency and tumour mutational burden) and assesses the evidence for new potential biomarkers.

Immune Checkpoint Blockade in Lung Carcinoids with Aggressive Behaviour: One More Arrow in Our Quiver?

Lung carcinoids are well-differentiated and low-/intermediate-grade neuroendocrine neoplasms of the lung. Given their relative rarity, and the paucity of data available from prospective studies, no global consensus exists on the systemic treatment of these tumours. In recent years, immune checkpoint inhibitors have revolutionized cancer management and are under evaluation in patients with diverse types of neuroendocrine neoplasms. The aim of this narrative review is to analyse all available data for the use of approved immune checkpoint inhibitors in patients with lung carcinoids. We performed an extensive search for relevant data sources and found five published articles, one meeting abstract, and nine registered clinical trials indicating a growing interest of researchers in this field, and providing preliminary evidence of efficacy for combined nivolumab plus ipilimumab and durvalumab plus tremelimumab regimens in the treatment of advanced and/or metastatic lung carcinoids.

Determining programmed cell death ligand 1 expression in circulating tumor cells of patients with clear cell renal cell carcinoma and its correlation with response to programmed cell death protein 1 inhibitors

OBJECTIVE

There is a great interest in determining whether the expression of the programmed cell death ligand 1 is correlated with the efficacy of immune checkpoint inhibitors in patients with clear cell renal cell carcinoma; however, primary tumor biopsies can only provide limited information. Therefore, we explored the expression of programmed cell death ligand 1 on circulating tumor cells, which is a potential predictor of therapeutic response.

METHODS

Circulating tumor cells were isolated from 20 clear cell renal cell carcinoma patients based on cell surface markers targeting clear cell renal cell carcinoma using IsoFlux device, followed by identification according to cell morphology and immunofluorescence studies. Programmed cell death ligand 1 expression status and clinical correlations were also analyzed.

RESULTS

Before treatment with programmed cell death protein 1 inhibitors, circulating tumor cells were detected in all patients, ranging from 1 to 22 (median 7), with 75% (15/20) of the patients having programmed cell death ligand 1 + circulating tumor cells. Circulating tumor cell programmed cell death ligand 1 expression did not correlate with the immunohistochemical staining of programmed cell death ligand 1 in primary tumors. During treatment with programmed cell death protein 1 inhibitors, the disease control rate was much higher in the patients harboring programmed cell death ligand 1 + circulating tumor cells (73%, 11/15) than others (20%, 1/5). We also found that changes in total circulating tumor cell numbers and programmed cell death ligand 1 + circulating tumor cell counts correlated well with the disease outcome.

CONCLUSION

We showed that the presence of programmed cell death ligand 1 + circulating tumor cells before programmed cell death protein 1 inhibition treatment could be a prognosis predictive factor and that the dynamic changes in circulating tumor cell numbers may be used to monitor the therapeutic response. Our study confirms the possibility of programmed cell death ligand 1 + circulating tumor cell detection in clear cell renal cell carcinoma patients' blood samples, which can potentially be used as an individualized immunotherapy molecular biomarker for real-time exploration.

Integrated Analysis Of Immunotherapy Treated Clear Cell Renal Cell Carcinomas: An Exploratory Study

Molecular or immunological differences between responders and nonresponders to immune checkpoint inhibitors (ICIs) of clear cell renal cell carcinomas (ccRCCs) remain incompletely understood. To address this question, we performed next-generation sequencing, methylation analysis, genome wide copy number analysis, targeted RNA sequencing and T-cell receptor sequencing, and we studied frequencies of tumor-infiltrating CD8+ T cells, presence of tertiary lymphoid structures (TLS) and PD-L1 expression in 8 treatment-naive ccRCC patients subsequently treated with ICI (3 responders, 5 nonresponders). Unexpectedly, we identified decreased frequencies of CD8+ tumor-infiltrating T cells and TLS, and a decreased expression of PD-L1 in ICI responders when compared with nonresponders. However, neither tumor-specific genetic alterations nor gene expression profiles correlated with response to ICI or the observed immune features. Our results underline the challenge to stratify ccRCC patients for immunotherapy based on routinely available pathologic primary tumor material, even with advanced technologies. Our findings emphasize the analysis of pretreated metastatic tissue in line with recent observations describing treatment effects on the tumor microenvironment. In addition, our data call for further investigation of additional parameters in a larger ccRCC cohort to understand the mechanistic implications of the observed differences in tumor-infiltrating CD8+ T cells, TLS, and PD-L1 expression.

Comparative Analysis of Predictive Biomarkers for PD-1/PD-L1 Inhibitors in Cancers: Developments and Challenges

Simple Summary

The development of immune checkpoint inhibitors (ICIs) has greatly changed the treatment landscape of multiple malignancies. However, the wide administration of ICIs is mainly obstructed by the low response rate and several life-threatening adverse events. Thus, there is an urgent need to identify sets of biomarkers to predict which patients will respond to ICIs. In this review, we discuss the recently investigated molecular and clinical determinants of ICI response, from the aspects of tumor features, clinical features, as well as tumor microenvironment.

Abstract

Immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1)/programmed death-ligand 1 (PD-L1) have dramatically changed the landscape of cancer therapy. Both remarkable and durable responses have been observed in patients with melanoma, non-small-cell lung cancer (NSCLC), and other malignancies. However, the PD-1/PD-L1 blockade has demonstrated meaningful clinical responses and benefits in only a subset of patients. In addition, several severe and life-threatening adverse events were observed in these patients. Therefore, the identification of predictive biomarkers is urgently needed to select patients who are more likely to benefit from ICI therapy. PD-L1 expression level is the most commonly used biomarker in clinical practice for PD-1/PD-L1 inhibitors. However, negative PD-L1 expression cannot reliably exclude a response to a PD-1/PD-L1 blockade. Other factors, such as tumor microenvironment and other tumor genomic signatures, appear to impact the response to ICIs. In this review, we examine emerging data for novel biomarkers that may have a predictive value for optimizing the benefit from anti-PD-1/PD-L1 immunotherapy.

Immune Checkpoint Inhibitor Therapy for Bone Metastases: Specific Microenvironment and Current Situation

The treatment of bone metastases is a thorny issue. Immunotherapy may be one of the few hopes for patients with unresectable bone metastases. Immune checkpoint inhibitors are the most commonly used immunotherapy drugs currently. In this review, the characteristics and interaction of bone metastases and their immune microenvironment were systematically discussed, and the relevant research progress of the immunological mechanism of tumor bone metastasis was reviewed. On this basis, we expounded the clinical application of immune checkpoint inhibitors for bone metastasis of common tumors, including non-small-cell lung cancer, renal cell carcinoma, prostate cancer, melanoma, and breast cancer. Then, the deficiencies and limitations in current researches were summarized. In-depth basic research on bone metastases and optimization of clinical treatment is needed.

Tumor cell PD-L1 expression is a strong predictor of unfavorable prognosis in immune checkpoint therapy-naive clear cell renal cell cancer

BACKGROUND

PD-L1 expression predicts response to immune checkpoint inhibitors in renal cell carcinomas (RCC), but has also been suggested to be linked to poor patient outcome.

METHODS

We analyzed PD-L1 in > 1400 RCC in a tissue microarray format by immunohistochemistry. Results were compared with histological tumor type, parameters of cancer aggressiveness, and intratumoral CD8+ cytotoxic cells.

RESULT

At a cut-off level of 5% PD-L1 positive tumor cells, PD-L1 positivity was seen in 6.3% of 633 clear cell RCC (ccRCC), 18.2% of 165 papillary RCC, 18.8% of 64 chromophobe RCC, and 41.7% of 103 oncocytomas. In ccRCC, PD-L1 positivity was significantly linked to high ISUP (p < 0.0001), Fuhrman (p < 0.0001), Thoenes grade (p < 0.0001), distant metastasis (p = 0.0042), short recurrence-free (p < 0.0001), and overall survival (p = 0.0002). Intratumoral CD8+ lymphocytes were more frequent in PD-L1 positive (1055 ± 109) than in PD-L1 negative ccRCC (407 ± 28; p < 0.0001). PD-L positive immune cells were seen in 8.2% of all RCC and 13.9% of papillary RCC. In ccRCC, PD-L1 positive immune cells were linked to high numbers of tumor-infiltrating CD8+ cells (p < 0.0001), high ISUP (p < 0.0001), Fuhrman (p = 0.0027), and Thoenes grade (p < 0.0001), and poor tumor-specific survival (p = 0.0280).

CONCLUSIONS

These data suggest that PD-L1 expression in highly immunogenic RCCs facilitates immune evasion and contributes to cancer aggressiveness.

From Bench to Bedside: How the Tumor Microenvironment Is Impacting the Future of Immunotherapy for Renal Cell Carcinoma

Immunotherapy has revolutionized the treatment landscape for many cancer types. The treatment for renal cell carcinoma (RCC) has especially evolved in recent years, from cytokine-based immunotherapies to immune checkpoint inhibitors. Although clinical benefit from immunotherapy is limited to a subset of patients, many combination-based approaches have led to improved outcomes. The success of such approaches is a direct result of the tumor immunology knowledge accrued regarding the RCC microenvironment, which, while highly immunogenic, demonstrates many unique characteristics. Ongoing translational work has elucidated some of the mechanisms of response, as well as primary and secondary resistance, to immunotherapy. Here, we provide a comprehensive review of the RCC immunophenotype with a specific focus on how preclinical and clinical data are shaping the future of immunotherapy.

Biomarkers in renal cell carcinoma: Are we there yet?

Management of kidney cancer has undergone a paradigm shift with the approval of new therapies over the last two decades. Although these drugs have improved clinical outcomes in patients with kidney cancer, there are still a large number of patients who do not show objective responses. A multitude of investigators, including those for The Cancer Genome Atlas have biologically characterized and sub-classified kidney cancer. However, we have not been able to identify molecular targets to effectively treat patients with kidney cancer. As we familiarize ourselves with newer drugs for patients with kidney cancer, it is important to understand that these drugs may not work in every patient and instead may expose patients to unnecessary toxic effects along with burdening society with the financial impact. As we head toward the era of "precision medicine", validated biomarkers are being utilized to guide treatment choices and help identify pathways of resistance in other tumor types. The current review aims at evaluating the progress made so far in this realm for patients with kidney cancer.

Multifunctional Nanocarriers-Mediated Synergistic Combination of Immune Checkpoint Inhibitor Cancer Immunotherapy and Interventional Oncology Therapy

Immune checkpoint inhibitor (ICI) cancer immunotherapies are becoming one of the standard therapies for cancer patients. However, ICI cancer immunotherapy's overall response rate is still moderate and even combinational ICI cancer immunotherapies are not showing significant improvement in therapeutic outcomes. Only a subset of patients responds to the therapy due to the resistance and ignorance to the ICI cancer immunotherapy. Following immune-related adverse events (irAEs) are also limiting the whole therapeutic regimens. New approaches that can increase the immunotherapeutic efficacy and reduce systemic irAEs are required. Recently, multifunctional nanocarriers, which can extend the half-life of ICIs and modulate tumor microenvironment (TME), have shown a substantial opportunity to enhance ICI cancer immunotherapies. Interventional oncology (IO) allowing simultaneous diagnosis, immunogenic loco-regional therapeutic delivery, and real-time monitoring of the treatment efficacy have advanced to demonstrate the effective conversion of TME. The use of multifunctional nanocarriers with the IO therapies amplify the image guidance capability and immunogenic therapeutic localization for the potential combinational ICI cancer immunotherapy. This article will discuss the emerging opportunity of multifunctional nanocarriers mediated synergistic combination of ICI cancer immunotherapy and IO local therapy.

Systematic Review of PD-1/PD-L1 Inhibitors in Oncology: From Personalized Medicine to Public Health

BACKGROUND

To review and summarize all U.S. Food and Drug Administration (FDA) approvals of programmed death (PD)-1 and PD-ligand 1 blocking antibodies (collectively referred to as PD-[L]1 inhibitors) over a 6-year period and corresponding companion/complementary diagnostic assays.

MATERIALS AND METHODS

To determine the indications and pivotal trials eligible for inclusion, approval letters and package inserts available on Drugs@FDA were evaluated for approved PD-[L]1 inhibitors to identify all new indications granted from the first approval of a PD-[L]1 inhibitor on September 4, 2014, through September 3, 2020. The corresponding FDA drug and device reviews from the marketing applications for the approved indications were identified through FDA internal records. Two reviewers independently extracted information for the endpoints, efficacy data, basis for approval, type of regulatory approval, and corresponding in vitro diagnostic device test. The results were organized by organ system and tumor type.

RESULTS

Of 70 Biologic Licensing Application or supplement approvals that resulted in new indications, 32 (46%) were granted based on response rate (ORR) and durability of response, 26 (37%) on overall survival, 9 (13%) on progression-free survival, 2 (3%) on recurrence-free survival, and 1 (1%) on complete response rate. Most ORR-based approvals were granted under the accelerated approval provisions and were supported with prolonged duration of response. Overall, 21% of approvals were granted with a companion diagnostic. Efficacy results according to tumor type are discussed.

CONCLUSION

PD-[L]1 inhibitors are an effective anticancer therapy in a subset of patients. This class of drugs has provided new treatment options for patients with unmet need across a wide variety of cancer types. Yet, the modest response rates in several tumor types signal a lack of understanding of the biology of these diseases. Further preclinical and clinical investigation may be required to identify a more appropriate patient population, particularly as drug development continues and additional treatment alternatives become available.

IMPLICATIONS FOR PRACTICE

The number of PD-[L]1 inhibitors in drug development and the associated companion and complementary diagnostics have led to regulatory challenges and questions regarding generalizability of trial results. The interchangeability of PD-L1 immunohistochemical assays between PD-1/PD-L1 drugs is unclear. Furthermore, robust responses in some patients with low levels of PD-L1 expression have limited the use of PD-L1 as a predictive biomarker across all cancers, particularly in the setting of diseases with few alternative treatment options. This review summarizes the biomarker thresholds and assays approved as complementary and companion diagnostics and provides regulatory perspective on the role of biomarkers in oncology drug development.

Eosinophilic features in clear cell renal cell carcinoma correlate with outcomes of immune checkpoint and angiogenesis blockade

BACKGROUND

Clear cell renal cell carcinoma (ccRCC) displays heterogeneity in appearance-a distinctive pale clear to eosinophilic cytoplasm; however, little is known about the underlying mechanisms and clinical implications. We investigated the role of these eosinophilic features in ccRCC on oncological outcomes and response to tyrosine kinase inhibitors (TKIs) and immune checkpoint inhibitors (ICIs).

METHODS

One-hundred and thirty-eight ccRCC cases undergoing radical surgery (cohort 1) and 54 metastatic ccRCC cases receiving either TKIs or ICIs (cohort 2) were included. After histological evaluation, all cases were divided into three phenotypes based on the eosinophilic features at the highest-grade area: clear, mixed, or eosinophilic type. Gene expression and immunohistochemical analyses were performed to explore the potential mechanisms of these phenotypes in cohort 1. Further, the association of the three phenotypes with the best objective response to TKI or ICI, clinical benefit (complete/partial response or stable disease), and overall survival (OS) was assessed in cohort 2.

RESULTS

The clear type was significantly associated with increased hypoxia as well as angiogenesis gene signatures compared with the eosinophilic type. Gene signatures and protein expression related to effector T cell and immune checkpoint molecules were elevated to a greater extent in the eosinophilic type, followed by the mixed and clear types. The mixed and eosinophilic types exhibited greater PBRM1-negativity and increased prevalence of the epithelial-mesenchymal transition gene signature than the clear type. In the mixed/eosinophilic types of cohort 2, significant clinical benefit was observed in the ICI therapy group versus the TKI therapy group (p=0.035), and TKI therapy vs ICI therapy was an independent factor for worse prognosis of OS (HR 3.236; p=0.012).

CONCLUSION

The histological phenotype based on the eosinophilic features, which are linked to major immunological mechanisms of ccRCC, was significantly correlated with therapeutic efficacy.

PD-1/PD-L1 inhibitors-based treatment for advanced renal cell carcinoma: Mechanisms affecting efficacy and combination therapies

With the widespread use of PD-1/PD-L1 monoclonal antibodies (mAbs) in the treatment of multiple malignant tumors, they were also gradually applied to advanced renal cell carcinoma (aRCC). Nowadays, multiple PD-1/PD-L1 mAbs, such as nivolumab, avelumab, and pembrolizumab, have achieved considerable efficacy in clinical trials. However, due to the primary, adaptive, and acquired resistance to these mAbs, the efficacy of this immunotherapy is not satisfactory. Theories also vary as to why the difference in efficacy occurs. The alterations of PD-L1 expression and the interference of cellular immunity may affect the efficacy. These mechanisms demand to be revealed to achieve a sustained and complete objective response in patients with aRCC. Tyrosine kinase inhibitors have been proven to have synergistic mechanisms with PD-1/PD-L1 mAb in the treatment of aRCC, and CTLA-4 mAb has been shown to have a non-redundant effect with PD-1/PD-L1 mAb to enhance efficacy. Although combinations with targeted agents or other checkpoint mAbs have yielded enhanced clinical outcomes in multiple clinical trials nowadays, the potential of PD-1/PD-L1 mAbs still has a large development space. More potential mechanisms that affect the efficacy demand to be developed and transformed into the clinical treatment of aRCC to search for possible combination regimens. We elucidate these mechanisms in RCC and present existing combination therapies applied in clinical trials. This may help physicians' select treatment options for patients with refractory kidney cancer.

[Biomarkers for renal cell tumours]

During the last three decades, renal tumours have become increasingly well differentiated on the basis of their histopathological and molecular features. This subtyping has increasingly impacted clinical practice because more therapeutic options are available in organ-confined and metastatic renal cell tumours. The knowledge of the underlying molecular alterations is essential to develop molecular targeted therapies and to select the most effective systemic therapy for each patient. This manuscript gives an overview of the molecular differentiation on the one hand, and on diagnostic, prognostic and predictive biomarkers on the other hand.

Characterization of tumor mutation burden, PD-L1 and DNA repair genes to assess relationship to immune checkpoint inhibitors response in metastatic renal cell carcinoma

Background

Immune checkpoint inhibitors (ICIs) have expanded treatment options for metastatic renal cell carcinoma (mRCC); however, there are limited predictive biomarkers for response to ICIs in this indication, with programmed death-ligand 1 (PD-L1) status demonstrating little predictive utility in mRCC. While predictive of ICI response in other tumor types, the utility of tumor mutation burden (TMB) in mRCC is unclear. Here, we assess TMB, loss of antigen presentation genes and PD-L1 status correlated with outcomes to ICI treatment in mRCC.

Methods

Tumor samples from 34 patients with mRCC treated with ICI therapy at Duke Cancer Institute were retrospectively evaluated using Personal Genome Diagnostics elio tissue complete (RUO version), a tumor genomic profiling assay for somatic variants, TMB, microsatellite status and genomic status of antigen presentation genes. Tumor samples were also analyzed with the Dako 28-8 PD-L1 immunohistochemistry assay. Deidentified clinical information was extracted from the medical record, and tumor response was evaluated based on the Response Evaluation Criteria In Solid Tumors (RECIST) V.1.1 criteria.

Results

Patients were stratified by overall response following ICI therapy and designated as progressive disease (PD; n=18) or disease control groups (DC; n=16). TMB scores ranged from 0.36 to 12.24 mutations/Mb (mean 2.83 mutations/Mb) with no significant difference between the PD and DC groups (3.01 vs 2.63 mutations/Mb, respectively; p=0.7682). Interestingly, 33% of PD patients displayed loss of heterozygosity of major histocompatibility complex class I genes (LOH-MHC) vs 6% of DC patients. Nine of 34 samples were PD-L1-positive (4 in the PD group; 5 in the DC group), suggesting no correlation between PD-L1 expression and response to ICI therapy. Notably, the DC group displayed an enrichment of mutations in DNA repair genes (p=0.04), with 68.8% exhibiting at least one mutated homologous recombination repair (HRR)-related gene compared with only 38.9% of the PD group (p=0.03).

Conclusions

Overall, neither TMB nor PD-L1 correlated with ICI response and TMB was not significantly associated with PD-L1 expression. The higher incidence of LOH-MHC in PD group suggests that loss of antigen presentation may restrict response to ICIs. Separately, enrichment of HRR gene mutations in the DC group suggests potential utility in predicting ICI response and a potential therapeutic target, warranting future studies.

PD-L1 expression in bladder cancer: Which scoring algorithm in what tissue?

INTRODUCTION

For cisplatin-ineligible patients, approval of first-line immune-checkpoint inhibitor therapy relies on the programmed death ligand 1 (PD-L1) expression assay employed, namely, the combined positive score (CPS) or immune cell (IC) score. This study compares PD-L1 diagnostic scores and positivity in primary and matched metastatic bladder cancer tissue.

METHODS

A total of 108 patients undergoing radical cystectomy for urothelial bladder cancer and lymphatic spread (pN+) were included. PD-L1 expression was compared by immunohistochemistry (IHC) between the primary bladder tumor and associated lymph node metastases using Ventana SP263 anti-PD-L1 antibody. In a subset of cases further IHC was performed with Ventana SP142 and Dako 22C3 antibodies. Second, the PD-L1 scoring algorithms for the CPS and IC score were compared. Correlation of PD-L1 positivity with clinical parameters and tumor stage was assessed. Intra- and intertissue analyses were performed with Pearson's chi square test, McNemar test and Spearman correlation employing IBM SPSS 25.

RESULTS

PD-L1 expression did not correlate with clinicopathological parameters. The CPS (43.5% vs. 35.6%; P=0.006) and the IC score (28.7% vs. 21.2%; P=0.002) yielded PD-L1 positivity significantly more often in primary BC than in matched lymph node metastasis. Both the CPS (r=0.775; P<0.001) and the IC score (r=0.711; P<0.001) correlated between primary and metastatic bladder cancer tissue. Employing CPS vs. IC led to significantly more PD-L1-positive classified cases in primary BC (CPS vs. IC; 43.5% vs. 28.7%; P<0.001) and lymph node metastasis (CPS vs. IC; 35.6% vs. 21.2%, P<0.001).

CONCLUSION

Compared to lymph node analysis, bladder tissue yields more PD-L1 positivity assessed with the CPS and IC scores. This is particularly evident when employing the CPS. The findings highlight that employing both PD-L1 assays may maximize eligibility for first-line checkpoint-inhibitors to treat bladder cancer patients unfit for cisplatin-based chemotherapy.

Cancer-specific immune evasion and substantial heterogeneity within cancer types provide evidence for personalized immunotherapy

The immune response against cancer is orchestrated by various parameters and site-dependent specificities have been poorly investigated. In our analyses of ten different cancer types, we describe elevated infiltration by regulatory T cells as the most common feature, while other lymphocyte subsets and also expression of immune-regulatory molecules on tumor-infiltrating lymphocytes showed site-specific variation. Multiparametric analyses of these data identified similarities of renal and liver or lung with head and neck cancer. Co-expression of immune-inhibitory ligands on tumor cells was most frequent in colorectal, lung and ovarian cancer. Genes related to antigen presentation were frequently dysregulated in liver and lung cancer. Expression of co-inhibitory molecules on tumor-infiltrating T cells accumulated in advanced stages while T-cell abundance was related to enhanced expression of genes related to antigen presentation. Our results promote evaluation of cancer-specific or even personalized immunotherapeutic combinations to overcome primary or secondary resistance as major limitation of immune-checkpoint inhibition.

Comparison of PD-L1 Scores in Primary Kidney Tumors Versus Accompanying Venous Tumor Thrombi: Retrospective, Comparative, Monocentric Study in Treatment-Naive Patients

Introduction

Renal cell carcinoma (RCC), an immunogenic tumor, is the most common form of kidney cancer worldwide. Immune checkpoint inhibitors (ICIs) play an important role in the treatment of metastatic RCC. Programmed death-ligand (PD-L1) has already been proposed as a possible prognosticator for ICIs effectiveness. To elucidate the feasible role of ICIs in neoadjuvant settings, we have assessed the most common PD-L1 expression modalities [tumor proportion score (TPS), combined positivity score (CPS) and inflammatory cell (IC) score] in primary tumors (PTs) and venous tumor thrombi (VTT) in first diagnosed, previously untreated RCC patients with accompanying VTT.

Methods

Between January 1999 and December 2016, 71 patients with a first diagnosed, untreated, locally advanced RCC (aRCC) (≥ pT3a) underwent surgery in Hanover Medical School (MHH). PD-L1 expression was examined separately in PTs and VTT using the CPS, IC score and TPS. We also considered the age at the time of the initial surgery and gender as probable influencing factors. By using a cutoff value of 1 (1%), PD-L1 expression levels in PTs and VTT were assessed to enable the determination of any frequency differences.

Results

Positive scores for PTs were shown by 54 (CPS), 53 (IC score) and 34 (TPS) patients, whereas in VTT, positive scores were evaluated for a total of 50 (CPS), 47 (IC-score) and 36 (TPS) patients. No statistically significant differences were obtained between the PD-L1 expression immunoscores for PTs and VTT. The covariates age at the time of the initial surgery and gender could not be statistically proven to influence the differences in PD-L1 expression between the VTT and PTs.

Conclusion

To the best of our knowledge, this research is the largest study to investigate PD-L1 expression in PTs and VTT in 71 cases. It could have relevance for the future development of neoadjuvant immunotherapy options, particularly in aRCC with VTT.

Checkpoint inhibitors in metastatic papillary renal cell carcinoma

Papillary Renal Cell Carcinoma (pRCC) is the most common non-clear cell RCC (nccRCC) and a distinct entity, although heterogenous, associated with poor outcomes. The treatment landscape of metastatic pRCC (mpRCC) relied so far on targeted therapies, mimicking previous developments in metastatic clear-cell renal cell carcinoma. However, antiangiogenics as well as mTOR inhibitors retain only limited activity in mpRCC. As development of immune checkpoint inhibitors (ICI) is now underway in patients with mpRCC, we aimed at discussing early activity data and potential for future therapeutic strategies in monotherapy or combination. Expression of immune checkpoints such as PD-L1 and infiltrative immune cells in pRCC could provide insights into their potential immunogenicity, although this is currently poorly described. Based on retrospective and prospective data, efficacy of ICI as single agent remains limited. Combinations with tyrosine-kinase inhibitors, notably with anti-MET inhibitors, harbor promising response rates and may enter the standard of care in untreated patients. Collaborative work is needed to refine the molecular and immune landscape of pRCC, and pursue efforts to set up predictive biomarker-driven clinical trials in these rare tumors.