Differential Activity of Nivolumab, Pembrolizumab and MPDL3280A according to the Tumor Expression of Programmed Death-Ligand-1 (PD-L1): Sensitivity Analysis of Trials in Melanoma, Lung and Genitourinary Cancers

Anti-PD-1 therapy activates tumoricidic properties of NKT cells and contributes to the overall deceleration of tumor progression in a model of murine mammary carcinoma

Background/Aim. Immune checkpoint therapy is a well-established therapeutic approach in the treatment of malignant diseases and is thought to be mostly based on facilitating the adaptive immune response. However, the cells of the innate immune response, such as natural killer T (NKT) cells, might also be important for a successful anti-programmed cell death protein-1 (anti-PD-1) therapy, as they initiate the antitumor immune response. The aim of this study was to investigate the influence of anti-PD-1 therapy on the immune response against tumors. Methods. For tumor induction, 4T1 cells synergic to BALB/c back-ground were used, after which mice underwent anti-PD-1 treatment. After the mice were sacrificed, NKT cells, dendritic cells (DCs), and macrophages derived from spleen and primary tumor tissue were analyzed using flow cytometry. Results. Anti-PD-1 therapy enhanced the expression of activating molecules CD69, NKp46, and NKG2D in NKT cells of the tumor and spleen. This therapy activated NKT cells directly and indirectly via DCs. Activated NKT cells acquired tumoricidic properties directly, by secreting perforin, and indirectly by stimulating M1 macrophages polarization. Conclusion. Anti-PD-1 therapy activates changes in DCs and macrophages of primary tumor tissue towards protumoricidic activity. Since anti-PD-1 therapy induces significant changes in NKT cells, DCs, and macrophages, the efficacy of the overall antitumor response is increased and has significantly decelerated tumor growth.

Comprehensive analysis of PD-L1 in non-small cell lung cancer with emphasis on survival benefit, impact of driver mutation and histological types, and archival tissue

Background

The aim of the study was to assess programmed death‐ligand‐1 (PD‐L1) expression in different histological types and gene mutation status of patients with non‐small cell lung cancer (NSCLC).

Methods

A total of 4062 pathology‐confirmed lung cancer patients were retrospectively screened at Kaohsiung Chang Gung Memorial Hospital from November 2010 to June 2017. There were 699 NSCLC patients with confirmed PD‐L1 expression level retrospectively enrolled for analysis.

Results

There was a trend of higher PD‐L1 expression in squamous cell carcinoma and adenosquamous cell carcinoma than in adenocarcinoma (p = 063). Significant higher PD‐L1 expression in EGFR wild‐type was noted (p < 0.001). No significant differences in PD‐L1 expression were found between ALK wild‐ and mutant types, but there seem was a trend of high PD‐L1 level noted in ALK mutation patients (p = 0.069). In EGFR mutation patients, a higher time to treatment failure (TTF) duration was observed in no PD‐L1 expression (p = 0.011). Longer tumor tissue storage time correlated with lower PD‐L1 expression in lung cancer (p < 0.001 for linear trend).

Conclusions

There were a trend or significant differences in PD‐L1 expression between different histological types in NSCLC, different EGFR and ALK status, and different tumor tissue storage time. A higher survival benefit was observed in no PD‐L1 expression than with PD‐L1 expression in adenocarcinoma, EGFR and ALK mutation patients. We recommend that PD‐L1 assay should be performed as early as possible if tissue is available.

Early prediction of clinical response to checkpoint inhibitor therapy in human solid tumors through mathematical modeling

Background:

Checkpoint inhibitor therapy of cancer has led to markedly improved survival of a subset of patients in multiple solid malignant tumor types, yet the factors driving these clinical responses or lack thereof are not known. We have developed a mechanistic mathematical model for better understanding these factors and their relations in order to predict treatment outcome and optimize personal treatment strategies.

Methods:

Here, we present a translational mathematical model dependent on three key parameters for describing efficacy of checkpoint inhibitors in human cancer: tumor growth rate (α), tumor-immune infiltration (Λ), and immunotherapy-mediated amplification of anti-tumor response (µ). The model was calibrated by fitting it to a compiled clinical tumor response dataset (n = 189 patients) obtained from published anti-PD-1 and anti-PD-L1 clinical trials, and then validated on an additional validation cohort (n = 64 patients) obtained from our in-house clinical trials.

Results:

The derived parameters Λ and µ were both significantly different between responding versus nonresponding patients. Of note, our model appropriately classified response in 81.4% of patients by using only tumor volume measurements and within 2 months of treatment initiation in a retrospective analysis. The model reliably predicted clinical response to the PD-1/PD-L1 class of checkpoint inhibitors across multiple solid malignant tumor types. Comparison of model parameters to immunohistochemical measurement of PD-L1 and CD8+ T cells confirmed robust relationships between model parameters and their underlying biology.

Conclusions:

These results have demonstrated reliable methods to inform model parameters directly from biopsy samples, which are conveniently obtainable as early as the start of treatment. Together, these suggest that the model parameters may serve as early and robust biomarkers of the efficacy of checkpoint inhibitor therapy on an individualized per-patient basis.

Funding:

We gratefully acknowledge support from the Andrew Sabin Family Fellowship, Center for Radiation Oncology Research, Sheikh Ahmed Center for Pancreatic Cancer Research, GE Healthcare, Philips Healthcare, and institutional funds from the University of Texas M.D. Anderson Cancer Center. We have also received Cancer Center Support Grants from the National Cancer Institute (P30CA016672 to the University of Texas M.D. Anderson Cancer Center and P30CA072720 the Rutgers Cancer Institute of New Jersey). This research has also been supported in part by grants from the National Science Foundation Grant DMS-1930583 (ZW, VC), the National Institutes of Health (NIH) 1R01CA253865 (ZW, VC), 1U01CA196403 (ZW, VC), 1U01CA213759 (ZW, VC), 1R01CA226537 (ZW, RP, WA, VC), 1R01CA222007 (ZW, VC), U54CA210181 (ZW, VC), and the University of Texas System STARS Award (VC). BC acknowledges support through the SER Cymru II Programme, funded by the European Commission through the Horizon 2020 Marie Skłodowska-Curie Actions (MSCA) COFUND scheme and the Welsh European Funding Office (WEFO) under the European Regional Development Fund (ERDF). EK has also received support from the Project Purple, NIH (U54CA210181, U01CA200468, and U01CA196403), and the Pancreatic Cancer Action Network (16-65-SING). MF was supported through NIH/NCI center grant U54CA210181, R01CA222959, DoD Breast Cancer Research Breakthrough Level IV Award W81XWH-17-1-0389, and the Ernest Cockrell Jr. Presidential Distinguished Chair at Houston Methodist Research Institute. RP and WA received serial research awards from AngelWorks, the Gillson-Longenbaugh Foundation, and the Marcus Foundation. This work was also supported in part by grants from the National Cancer Institute to SHC (R01CA109322, R01CA127483, R01CA208703, and U54CA210181 CITO pilot grant) and to PYP (R01CA140243, R01CA188610, and U54CA210181 CITO pilot grant). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

SLAMF8 expression predicts the efficacy of anti-PD1 immunotherapy in gastrointestinal cancers

Objectives

Epstein–Barr virus (EBV) infection is associated with a better response to anti‐PD1 immunotherapy. We hypothesised that genetic alterations induced by EBV infection are responsible for the activation of key immune responses and hence are predictive of anti‐PD1 efficacy.

Methods

With transcriptome data of gastric cancer (GC), we explored differentially expressed genes (DEGs) specific for EBV infection and performed coexpression network analysis using the DEGs to identify the consistent coexpression genes (CCGs) between EBV‐positive and EBV‐negative GC tissues. We selected the tag genes of the CCGs and validated them using RNA sequencing and immunohistochemistry. We established murine models and collected tissues from clinical patients to test the value of SLAMF8 in predicting anti‐PD1 treatment. The location and expression of SLAMF8 were characterised by multiplex immunofluorescence and quantitative PCR. Moreover, exogenous overexpression and RNA‐sequencing analysis were used to test the potential function of SLAMF8.

Results

We identified 290 CCGs and validated the tag gene SLAMF8 in transcriptome data of gastrointestinal cancer (GI). We observed that the T‐cell activation pathway was significantly enriched in high‐expression SLAMF8 GI cancers. Higher SLAMF8 expression was positively associated with CD8 expression and a better response to anti‐PD1 treatment. We further observed dynamically increased expression of SLAMF8 in murine models relatively sensitive to anti‐PD1 treatment. SLAMF8 was mainly expressed on the surface of macrophages. Exogenous overexpression of SLAMF8 in macrophages resulted in enrichment of positive regulation of multiple immune‐related pathways.

Conclusion

Higher SLAMF8 expression may predict better anti‐PD1 immunotherapy efficacy in GI cancer.

The effects of PD-1/PD-L1 checkpoint inhibitors on recurrent/metastatic head and neck squamous cell carcinoma: a critical review of the literature and meta-analysis

INTRODUCTION

50% of patients with locally advanced HNSCC eventually present with disease recurrence or metastasis. Interaction of programmed cell death protein 1 (PD-1) and its ligand, programmed death-ligand 1 (PD-L1), allows tumour cells to evade immune attack by inhibiting T-cell activation. PD-1/PD-L1 checkpoint inhibitors block this immunosuppressive effect. This study aims to investigate the efficacy of anti-PD-1/PD-L1 agents for recurrent/metastatic (R/M) HNSCC in terms of survival, toxicity, and response. It will test the hypothesis that immunotherapy improves treatment outcomes for R/M HNSCC patients.

MATERIAL AND METHODS

Studies were identified through an electronic search of databases EMBASE and Medline. Data on survival, response and toxicity following PD-1/PD-L1 inhibition was extracted from included studies and compared. A subgroup meta-analysis compared these outcomes in PD-1/PD-L1 inhibition versus the standard of care (SOC).

RESULTS

Thirteen studies (n = 1798) were included in this review. Overall survival following PD-1/PD-L1 checkpoint inhibition ranged from 6 to 13 months. The most common treatment-related adverse events (TRAEs) were fatigue, hypothyroidism and nausea; Grade ≥3 TRAEs occurred in 13% of patients. Meta-analysis of RCTs showed that anti-PD-1/PD-L1 agents improved survival and reduced toxicity compared to the SOC. This was demonstrated by a 37% lower risk of death (OR = 0.63, 95% CI = 0.51-0.78, I² = 18%, p ≤ 0.0001) and a 77% lower risk of any-grade TRAEs (OR = 0.23, 95% CI = 0.18-0.29, I² = 90%, p ≤ 0.00001) with immunotherapy versus SOC.

DISCUSSION

Based on the observed safety and efficacy, PD-1/PD-L1 checkpoint inhibition improves treatment outcomes for R/M HNSCC patients. PD-1/PD-L1 inhibitors significantly prolonged survival and reduced toxicity compared to the SOC, however further randomised trials are needed to investigate their role in HNSCC.

Immunohistochemical expression of programmed death-ligand 1 and CD8 in glioblastomas

BACKGROUND

Glioblastoma is the most aggressive primary malignant brain tumor in adults and is characterized by poor prognosis. Immune evasion occurs via programmed death-ligand 1 (PD-L1)/programmed death receptor 1 (PD-1) interaction. Some malignant tumors have responded to PD-L1/PD-1 blockade treatment strategies, and PD-L1 has been described as a potential predictive biomarker. This study discussed the expression of PD-L1 and CD8 in glioblastomas.

METHODS

Thirty cases of glioblastoma were stained immunohistochemically for PD-L1 and CD8, where PD-L1 expression in glioblastoma tumor tissue above 1% is considered positive and CD-8 is expressed in tumor infiltrating lymphocytes. The expression of each marker was correlated with clinicopathologic parameters. Survival analysis was conducted to correlate progression-free survival (PFS) and overall survival (OS) with PD-L1 and CD8 expression.

RESULTS

Diffuse/fibrillary PD-L1 was expressed in all cases (mean expression, 57.6%), whereas membranous PD-L1 was expressed in six of 30 cases. CD8-positive tumor-infiltrating lymphocytes (CD8+ TILs) had a median expression of 10%. PD-L1 and CD8 were positively correlated (p = .001). High PD-L1 expression was associated with worse PFS and OS (p = .026 and p = .001, respectively). Correlation of CD8+ TILs percentage with age, sex, tumor site, laterality, and outcomes were statistically insignificant. Multivariate analysis revealed that PD-L1 was the only independent factor that affected prognosis.

CONCLUSIONS

PD-L1 expression in patients with glioblastoma is robust; higher PD-L1 expression is associated with lower CD8+ TIL expression and worse prognosis.

Abscopal Effects in Metastatic Cancer: Is a Predictive Approach Possible to Improve Individual Outcomes?

Patients with metastatic cancers often require radiotherapy (RT) as a palliative therapy for cancer pain. RT can, however, also induce systemic antitumor effects outside of the irradiated field (abscopal effects) in various cancer entities. The occurrence of the abscopal effect is associated with a specific immunological activation in response to RT-induced cell death, which is mainly seen under concomitant immune checkpoint blockade. Even if the number of reported apscopal effects has increased since the introduction of immune checkpoint inhibition, its occurrence is still considered rare and unpredictable. The cases reported so far may nevertheless allow for identifying first biomarkers and clinical patterns. We here review biomarkers that may be helpful to predict the occurrence of abscopal effects and hence to optimize therapy for patients with metastatic cancers.

Cemiplimab in advanced cutaneous squamous cell carcinoma

Cemiplimab, a high-affinity, highly potent human monoclonal antibody that binds to the programmed death-1 (PD-1)/programmed death ligand-1 (PD-L1) receptor, is the only drug to attain Food and Drug Administration (FDA) approval and marketing authorization from the European Commission for use in patients with metastatic and locally advanced cutaneous squamous cell carcinoma (CSCC) who are not candidates for curative surgery or curative radiation therapy as a first- or later-line treatment. In pivotal phase II clinical testing, cemiplimab showed rapid and substantial antitumor efficacy and acceptable safety. This systematic review was aimed at evaluating the efficacy and safety of cemiplimab in patients with advanced CSCC. To this end, I reviewed EMBASE, MEDLINE, PubMed, and clinical trial registries/databases by using the following keywords alone or in combination: "cemiplimab," "Libtayo," "cutaneous squamous cell carcinoma," "REGN2810," and "SER439684." Cemiplimab showed clinical efficacy and considerable safety and was associated with low rates of treatment discontinuation (7%) and death (3%). However, the current recommendation is primarily based on only phase II clinical testing due to the absence of an approved comparator agent.

Case Report: Pulmonary Metastases From Epithelioid Sarcoma in Extremity Favourably Responding to Immunotherapy With Camrelizumab

Epithelioid sarcoma (ES) is a rare soft tissue sarcoma (STS), with limited therapies available for metastatic disease. Here, we describe a case of a 30-year-old male with ES of the left knee and underwent surgery and radiation therapy for the primary disease. After 2 years, he had local recurrence and underwent extensive resection surgery; however, adjuvant chemotherapies were delayed due to recurrent wound infection. Nine months after the second surgery, progressive disease was confirmed after detection of metastases to the lungs and inguinal lymph nodes. Amputation was performed for the local recurrence, followed by inguinal lymph nodes dissection. Pazopanib was transiently administered but discontinued as a result of wound dehiscence. The tumour specimens were detected with unexpected high level of PD-L1 expression and tumoural infiltrating lymphocytes. Subsequently, he received camrelizumab 2.0 mg/kg every 21 days for 18 cycles with rapid remission of the pulmonary metastases. This promising response to camrelizumab indicates that immunotherapies may be an alternative choice for patients with metastatic ES in lung based on analysing the tumour immune microenvironment.

Soluble PD-L1 is a predictive and prognostic biomarker in advanced cancer patients who receive immune checkpoint blockade treatment

Circulating soluble programmed death-1 ligand (sPD-L1) is measurable in the serum of cancer patients. This study aimed to investigate the significance of sPD-L1 in cancer patients receiving immune checkpoint inhibitor therapy. Blood samples were obtained before and after immune checkpoint inhibitor therapy (January 2015 to January 2019). The study cohort consisted of 128 patients who were diagnosed with non-small cell lung cancer (n = 50), melanoma (n = 31), small cell lung cancer (n = 14), urothelial carcinoma (n = 13), and other cancers (n = 20). Patients with a high level (> 11.0 pg/μL) of sPD-L1 were more likely to exhibit progressive disease compared with those with a low level (41.8% versus 20.7%, p = 0.013). High sPD-L1 was also associated with worse prognosis; the median PFS was 2.9 (95% confidence interval [CI] 2.1-3.7) months versus 6.3 (95% CI 3.0-9.6) months (p = 0.023), and the median OS was 7.4 (95% CI 6.3-8.5) months versus 13.3 (95% CI 9.2-17.4) months (p = 0.005). In the multivariate analyses, high sPD-L1 was an independent prognostic factor for both decreased PFS (HR 1.928, p = 0.038) and OS (HR 1.788, p = 0.004). sPD-L1 levels did not correlate with tissue PD-L1 expression. However, sPD-L1 levels were positively correlated with neutrophil to lymphocyte ratios and negatively correlated with both the proportion and the total number of lymphocytes. We found that high pretreatment sPD-L1 levels were associated with progressive disease and were an independent prognostic factor predicting lower PFS and OS in these patients.

Rapid Response to Pembrolizumab in a Chemo-Refractory Testicular Germ Cell Cancer with Microsatellite Instability-High

Testicular germ cell tumor (TGCT) is highly chemo-sensitive cancer; however, there is no established treatment for TGCT relapsed after multiple chemotherapy. Although pembrolizumab showed durable stable disease in some patients, no reliable biomarker for predicting response is available. High microsatellite instability (MSI) is rare in chemo-naïve TGCT. We report a TGCT patient with a rapid response to pembrolizumab. A 34-year-old Japanese male diagnosed with advanced TGCT underwent PCR-based testing of the primary site; it did not reveal MSI. He relapsed after four chemotherapy regimens: bleomycin, etoposide and cisplatin; paclitaxel, ifosfamide and cisplatin; vinblastine, ifosfamide and cisplatin; and irinotecan+nedaplatin with a total of 20 treatment cycles. Chemotherapy was thus discontinued. Re-examination by a CT-guided needle biopsy for progressing retroperitoneal lymph node (RPLN) metastases showed MSI-high; pembrolizumab was initiated. After only two doses, the human chorionic gonadotropin level decreased from 6500 to <1.0 IU/L. PET-CT showed shrinkage of the RPLN metastases with diminished metabolism. The patient is currently free from disease progression for 6 months from the start of pembrolizumab. This is the first report of refractory TGCT with MSI-high responding to pembrolizumab. We emphasize the utility of a metastatic-site biopsy to check the MSI status for refractory TGCT even when primary site is MSI-negative.

PD-1 inhibition in advanced myeloproliferative neoplasms

This is the first report demonstrating the safety and lack of efficacy of pembrolizumab treatment in patients with advanced MPNs.

Pembrolizumab was associated with changes in the immune milieu that could potentially support antitumor immunity in patients with advanced MPNs.

Myelofibrosis (MF) is a clonal stem cell neoplasm characterized by abnormal JAK-STAT signaling, chronic inflammation, cytopenias, and risk of transformation to acute leukemia. Despite improvements in the therapeutic options for patients with MF, allogeneic hematopoietic stem cell transplantation remains the only curative treatment. We previously demonstrated multiple immunosuppressive mechanisms in patients with MF, including increased expression of programmed cell death protein 1 (PD-1) on T cells compared with healthy controls. Therefore, we conducted a multicenter, open-label, phase 2, single-arm study of pembrolizumab in patients with Dynamic International Prognostic Scoring System category of intermediate-2 or greater primary, post-essential thrombocythemia or post-polycythemia vera myelofibrosis that were ineligible for or were previously treated with ruxolitinib. The study followed a Simon 2-stage design and enrolled a total of 10 patients, 5 of whom had JAK2^V617mutation, 2 had CALR mutation, and 6 had additional mutations. Most patients were previously treated with ruxolitinib. Pembrolizumab treatment was well tolerated, but there were no objective clinical responses, so the study closed after the first stage was completed. However, immune profiling by flow cytometry, T-cell receptor sequencing, and plasma proteomics demonstrated changes in the immune milieu of patients, which suggested improved T-cell responses that can potentially favor antitumor immunity. The fact that these changes were not reflected in a clinical response strongly suggests that combination immunotherapeutic approaches rather than monotherapy may be necessary to reverse the multifactorial mechanisms of immune suppression in myeloproliferative neoplasms. This trial was registered at www.clinicaltrials.gov as #NCT03065400.

Biomarkers of Targeted Therapy and Immuno-Oncology in Cancers Metastatic to the Breast

The breast is a rare site for metastases, and their molecular characteristics have not been studied yet. Intrinsic molecular genetics, cancer characteristics, and breast tissue immune responses in diverse metastases to the breast have not been previously studied. We identified 64 patients with cancers metastatic to the breast: 51 carcinomas and 13 melanomas. Programmed death ligand 1 (PD-L1), steroid receptors, and HER2/neu expressions were evaluated using immunohistochemistry. Gene sequencing, copy number alterations, microsatellite instability, and tumor mutational burden were performed using next-generation sequencing platforms. The 3 most common primary sites for metastatic carcinomas were lung (37%), ovary (29%), and fallopian tubes/peritoneum (14%). TP53 mutations were commonly (50%) observed among the carcinoma cases, while other mutations were characteristic for the primary cancers (VHL in renal, BRCA1 in the fallopian tube, and BRAF in melanomas). High tumor mutational burden was detected in 5/14 carcinomas and 3/7 melanomas. Tumor cell PD-L1 expression was detected in 6 carcinomas, but not in any of the melanomas, whereas immune cells' expression of PD-L1 was seen in 17 carcinomas and 6 melanomas. Estrogen receptor status was positive in 13/49 carcinomas including 12 adenocarcinomas originating from the ovary and fallopian tube or peritoneum and 1 duodenal neuroendocrine carcinoma. No carcinoma was HER2/neu positive. Intrinsic genetic characteristics of the metastases to the breast followed the pattern commonly seen in primary tumors. Biomarkers of potential benefit to immune checkpoint inhibition therapy were limited to PD-L1-positive non-small cell lung cancer. No common characteristics of the heterogeneous group of tumor metastases to this organ were identified.

Immune Cell Infiltration and the Expression of PD-1 and PD-L1 in Primary PDGFRA-Mutant Gastrointestinal Stromal Tumors

PURPOSE

To characterize the immune cell profile and expression of PD-1, PD-L1, and IDO in PDGFRA-mutant gastrointestinal stromal tumors (GISTs).

METHODS

The clinicopathological data of PDGFRA-mutant GIST patients who received surgical resection in Zhongshan Hospital between January 2013 and August 2019 were reviewed retrospectively. The specimens of tissue chips were detected for immune cell infiltration and the expression of PD-1, PD-L1, and IDO by immunohistochemical staining.

RESULTS

CD3⁺, CD8⁺, and CD68⁺ cells were the main infiltrating immune cells in the 42 patients included in this study. In addition, CD4⁺, CD56⁺, Foxp3⁺, and CD20⁺ cells were also observed. A higher CD8⁺ T cell count was associated with smaller tumor size and PDGFRA D842V mutation (P = 0.047, P = 0.005). A higher CD3⁺ and CD68⁺ cell count was associated with a higher mitotic index (P = 0.022, P = 0.006). CD4⁺ and CD20⁺ cell count was associated with tumor morphology (P = 0.002, P = 0.045). PD-1 expression was present in 37 (88%) samples. Eighteen samples were positive for PD-L1 expression, and it was higher in small vs. large tumors (P = 0.012) and epithelioid and mixed cell type vs. spindle cell type GISTs (P = 0.046). IDO expression was positive in all 42 patients. The number of CD4⁺ cells was significantly greater in the specimens with high IDO expression (P = 0.012).

CONCLUSION

There were abundant infiltrating immune cells in PDGFRA-mutant GISTs. PD-L1 expression was negatively associated with tumor size. The immunotherapy targeting PD-1/PD-L1 checkpoint and IDO may be valuable.

Phytochemicals in Cancer Immune Checkpoint Inhibitor Therapy

The interaction of immune checkpoint molecules in the tumor microenvironment reduces the anti-tumor immune response by suppressing the recognition of T cells to tumor cells. Immune checkpoint inhibitor (ICI) therapy is emerging as a promising therapeutic option for cancer treatment. However, modulating the immune system with ICIs still faces obstacles with severe immunogenic side effects and a lack of response against many cancer types. Plant-derived natural compounds offer regulation on various signaling cascades and have been applied for the treatment of multiple diseases, including cancer. Accumulated evidence provides the possibility of efficacy of phytochemicals in combinational with other therapeutic agents of ICIs, effectively modulating immune checkpoint-related signaling molecules. Recently, several phytochemicals have been reported to show the modulatory effects of immune checkpoints in various cancers in in vivo or in vitro models. This review summarizes druggable immune checkpoints and their regulatory factors. In addition, phytochemicals that are capable of suppressing PD-1/PD-L1 binding, the best-studied target of ICI therapy, were comprehensively summarized and classified according to chemical structure subgroups. It may help extend further research on phytochemicals as candidates of combinational adjuvants. Future clinical trials may validate the synergetic effects of preclinically investigated phytochemicals with ICI therapy.

Neutrophils in the era of immune checkpoint blockade

The immune checkpoint blockade-based immunotherapies are revolutionizing cancer management. Tumor-associated neutrophils (TANs) were recently highlighted to have a pivotal role in modulating the tumor microenvironment and the antitumor immune response. However, these cells were largely ignored during the development of therapies based on programmed cell death receptor or ligand-1 and cytotoxic T lymphocyte antigen-4 immune checkpoint inhibitors (ICIs). Latest evidences of neutrophil functional diversity in tumor raised many questions and suggest that targeting these cells can offer new treatment opportunities in the context of ICI development. Here, we summarized key information on TAN origin, function, and plasticity that should be considered when developing ICIs and provide a detailed review of the ongoing clinical trials that combine ICIs and a second compound that might affect or be affected by TANs. This review article synthetizes important notions from the literature demonstrating that: (1) Cancer development associates with a profound alteration of neutrophil biogenesis and function that can predict and interfere with the response to ICIs, (2) Neutrophil infiltration in tumor is associated with key features of resistance to ICIs, and (3) TANs play an important role in resistance to antiangiogenic drugs reducing their clinical benefit when used in combination with ICIs. Finally, exploring the clinical/translational aspects of neutrophil impact on the response to ICIs offers the opportunity to propose new translational research avenues to better understand TAN biology and treat patients.

Clinicopathological and prognostic values of PD-L1 expression in oesophageal squamous cell carcinoma: a meta-analysis of 31 studies with 5368 patients

Several immune checkpoint inhibitors targeting programmed death ligand 1 (PD-L1)/programmed death 1 have successfully improved the prognosis of oesophageal squamous cell carcinoma (ESCC) with approval in certain countries. However, whether the expression of PD-L1 is associated with the degree of benefit is unclear yet and a unified standard of antibody and cut-off value of PD-L1 detection is also lacking. The current meta-analysis then aimed to explore the association between PD-L1 expression and clinicopathological features as well as prognosis in ESCC.A systematic search on PubMed, Embase, Cochrane Library and Web of Science databases was performed up to 30 March 2021. The correlation between PD-L1 expression and clinicopathological features, as well as prognosis in ESCC, was estimated with the random-effects model.A total of 5368 patients from 31 retrospective studies were enrolled. The overexpression of PD-L1 was significantly associated with lymph node metastasis (OR 1.342, 95% CI 0.995 to 1.809, p=0.050) and distant metastasis (OR 1.516, 95% CI 1.001 to 2.294, p=0.050). The pooled HR showed that PD-L1 overexpression was significantly correlated with poor overall survival (OS) of patients with ESCC (HR 1.306, 95% CI 1.108 to 1.539, p<0.010) but not disease-free survival (DFS) (HR 1.180, 95% CI 0.937 to 1.487, p=0.160). Heterogeneity decreased significantly in subgroup analyses. The overexpression of PD-L1 was associated with poor DFS at the cut-off point of ≥1% (HR 1.642, 95% CI 1.367 to 1.973, p<0.010; I²=0%) and worse OS at the cut-off point of ≥10% (HR 1.575, 95% CI 1.175 to 2.111, p<0.010; I²=0%).The overexpression of PD-L1 was correlated with lymph node and distant metastasis as well as poor survival of ESCC.

Immune-related biomarkers in triple-negative breast cancer

Breast cancer is a commonly diagnosed female cancer in the world. Triple-negative breast cancer (TNBC) is the most dangerous and biologically aggressive subtype in breast cancer which has a high mortality, high rates of relapse and poor prognosis, representing approximately 15-20% of breast cancers. TNBC has unique and special biological molecular characteristics and higher immunogenicity than other breast cancer types. On the basis of molecular features, TNBC is divided into different subtypes and gets various treatments. Especially, immunotherapy becomes a promising and effective treatment to TNBC. However, not all of the TNBC patients are sensitive to immunotherapy, the need of selecting the patients suitable for immunotherapy is imperative. In this review, we discussed recent discoveries about the immune-related factors of TNBC, including tumor-infiltrating lymphocytes (TILs), programmed death-ligand protein-1 (PD-L1), immune gene signatures, some other emerging biomarkers for immunotherapy effectivity and promising biomarkers for immunotherapy resistance. In addition, we summarized the features of these biomarkers contributing to predict the prognosis and effect of immunotherapy. We hope we can provide some helps or evidences to clinical immunotherapy and combined treatment for TNBC patients.

Modern Challenges for Early-Phase Clinical Trial Design and Biomarker Discovery in Metastatic Non-Small-Cell Lung Cancer

Oncology research has changed extensively due to the possibility to categorize each cancer type into smaller subgroups based on histology and particularly on different genetic alterations due to their heterogeneity. The consequences of this heterogeneity are particularly evident in the management of metastatic non-small-cell lung cancer (NSCLC). This review will discuss the benefits and challenges of incorporating precision medicine into early- through late-phase metastatic NSCLC clinical trials, discussing examples of drug development programs in oncogene- and non-oncogene-addicted NSCLC. The experiences of clinical development of crizotinib, gefitinib and osimertinib are depicted showing that when a targeted drug is administrated in a study population not selected by any biomarker, trials could produce negative results. However, the early detection of biomarker-driven biology helps to obtain a greater benefit for a selected population and can reduce the required time for drug approval. Early clinical development programs involving nivolumab, pembrolizumab and avelumab, immune checkpoint inhibitors, taught us that, beyond safety and activity, the optimal selection of patients should be based on pre-specified biomarkers. Overall, the identification of predictive biomarkers is one of the greatest challenges of NSCLC research that should be optimized with solid methodological trial designs to maximize the clinical outcomes.

Preclinical development and characterisation of 99mTc-NM-01 for SPECT/CT imaging of human PD-L1

The level of expression of programmed cell death-1 (PD-1)/programmed death ligand-1 (PD-L1) is a predictive biomarker for cancer immunotherapy, however, its detection remains challenging due to tumour heterogeneity and the influence from the binding of therapeutic agents. We recently developed [^99mTc]-NM-01 as a companion diagnostic imaging agent for non-invasive molecular imaging of PD-L1 by single-photon emission computed tomography (SPECT). The aim of the study was to evaluate the [^99mTc] radiolabelling of GMP graded NM-01 and its pharmacology, pharmacokinetics and toxicology. NM-01 bound specifically to human PD-L1 (K_d=0.8 nM) and did not interfere with the binding of the anti-PD-L1 antibody atezolizumab. NM-01 can bind various PD-L1-positive cancer cell lines and only interact with PD-L1 expressed on the cell surface. In SPECT/CT imaging, high [^99mTc]-NM-01 accumulation was observed in the HCC827 mouse xenografted tumour model (30-min: 1.50 ± 0.27 %ID/g; 90-min: 1.23 ± 0.18 %ID/g), demonstrated a predominantly renal elimination (high uptake in bladder and kidney), while activity in the blood pool and other major organs remained low. The tumour-to-muscle and tumour-to-blood ratios were comparable with/without atezolizumab (P<0.04) but were significantly lowered when co-injected with excess NM-01 (P=0.04 and P=0.01, respectively.) The blood clearance of [^99mTc]-NM-01 is bi-phasic; consisting of an initial fast washout phase with half-life of 2.1 min and a slower clearance phase with half-life of 25.4 min. In an intravenous extended single-dose toxicity study, no treatment-related changes were observed and the maximum tolerated dose of [^99mTc]-NM-01 was 2.58 mg/kg. [^99mTc]-NM-01 has suitable properties as a potential candidate for SPECT/CT imaging of PD-L1 assessment in cancer patients.

Phase II and biomarker study of programmed cell death protein 1 inhibitor nivolumab and metronomic cyclophosphamide in paediatric relapsed/refractory solid tumours: Arm G of AcSé-ESMART, a trial of the European Innovative Therapies for Children With Cancer Consortium

PURPOSE

AcSé-ESMART is a European multicentre, proof-of-concept multiarm phase I/II platform trial in paediatric patients with relapsed/refractory cancer. Arm G assessed the activity and safety of nivolumab in combination with metronomic cyclophosphamide +/- irradiation.

EXPERIMENTAL DESIGN

Following a Phase II Simon two-stage design, nivolumab was administered intravenously at 3 mg/kg every 2 weeks of a 28-day cycle, oral cyclophosphamide at 25 mg/m2 twice a day, 1 week on/1 week off. The primary endpoint was objective response rate. Irradiation/radioablation of primary tumour or metastasis could be administered as per physician's choice. Biomarker evaluation was performed by tumour immunohistochemistry, whole exome and RNA sequencing, and immunophenotyping of peripheral blood by flow cytometry.

RESULTS

Thirteen patients were treated with a median age of 15 years (range: 5.5-19.4). The main histologies were high-grade glioma, neuroblastoma, and desmoplastic small round cell tumour (DSRCT). The safety profile was similar to those of single-agent nivolumab, albeit haematologic toxicity, mainly lymphocytopenia, was commonly reported with the addition of cyclophosphamide +/- irradiation. Two patients with DSRCT and ependymoma presented unconfirmed partial response and prolonged disease stabilisation. Low mutational load with modest intratumour CD3+ T-cell infiltration and immunosuppressive tumour microenvironment were observed in the tumour samples. Under combined treatment, no positive modulation of circulating T cells was displayed, while derived neutrophil-to-lymphocyte ratio increased.

CONCLUSIONS

Nivolumab in combination with cyclophosphamide was well tolerated but had limited activity in this paediatric setting. Metronomic cyclophosphamide did not modulate systemic immune response that could compensate limited T-cell infiltration and the immunosuppressive tumour microenvironment. CLINICALTRIALS.

GOV IDENTIFIER

NCT2813135.

Immunotherapy in Treating EGFR-Mutant Lung Cancer: Current Challenges and New Strategies

Lung cancer is the leading cause of cancer-related deaths worldwide. Immune checkpoint inhibitors, including monoclonal antibodies against programmed death-1 (PD-1) and programmed death ligand-1 (PD-L1), have dramatically improved the survival and quality of life of a subset of non-small cell lung cancer (NSCLC) patients. Multiple predictive biomarkers have been proposed to select the patients who may benefit from the immune checkpoint inhibitors. EGFR-mutant NSCLC is the most prevalent molecular subtype in Asian lung cancer patients. However, patients with EGFR-mutant NSCLC show poor response to anti-PD-1/PD-L1 treatment. While small-molecule EGFR tyrosine kinase inhibitors (TKIs) are the preferred initial treatment for EGFR-mutant NSCLC, acquired drug resistance is severely limiting the long-term efficacy. However, there is currently no further effective treatment option for TKIs-refractory EGFR-mutant NSCLC patients. The reasons mediating the poor response of EGFR-mutated NSCLC patients to immunotherapy are not clear. Initial investigations revealed that EGFR-mutated NSCLC has lower PD-L1 expression and a low tumor mutational burden, thus leading to weak immunogenicity. Moreover, the use of PD-1/PD-L1 blockade prior to or concurrent with osimertinib has been reported to increase the risk of pulmonary toxicity. Furthermore, emerging evidence shows that PD-1/PD-L1 blockade in NSCLC patients can lead to hyperprogressive disease associated with dismal prognosis. However, it is difficult to predict the treatment toxicity. New biomarkers are urgently needed to predict response and toxicity associated with the use of PD-1/PD-L1 immunotherapy in EGFR-mutated NSCLC. Recently, promising data have emerged to suggest the potentiation of PD-1/PD-L1 blockade therapy by anti-angiogenic agents and a few other novel therapeutic agents. This article reviews the current investigations about the poor response of EGFR-mutated NSCLC to anti-PD-1/PD-L1 therapy, and discusses the new strategies that may be adopted in the future.

Atezolizumab with bevacizumab, paclitaxel and carboplatin was effective for patients with SMARCA4-deficient thoracic sarcoma

SMARCA4-deficient thoracic sarcoma (DTS) is a recently noted progressive thoracic malignancy. We recently experienced three cases of SMARCA4-DTS who were treated with atezolizumab in combination with bevacizumab, paclitaxel and carboplatin (ABCP) as the first-line therapy. Immunohistopathological analysis revealed absent expression of SMARCA4 in all cases. The tumor mutational burden was over 11/Mb and mutations in SMARCA4 and TP53 were detected in all three cases. Partial response to ABCP treatment was observed in all three cases, with a progression-free survival of approximately 6 months or longer and a continuous response of 1 year or longer in one case. The first-line ABCP treatment demonstrated durable efficacy in SMARCA4-DTS regardless of the degree of PD-L1 expression.

Intertumoral Genetic Heterogeneity Generates Distinct Tumor Microenvironments in a Novel Murine Synchronous Melanoma Model

Simple Summary

Metastatic melanoma patients may present with multiple, simultaneous metastases that are genetically different. This intertumoral heterogeneity can cause these tumors to respond differently to the same systemic therapy. Progression of any one tumor, even when others regress, eventually leads to therapy termination. The mechanism underlying these mixed responses remains unknown due to a lack of clinically representative animal models. In a novel murine model of synchronous melanoma that recapitulates human intertumoral heterogeneity, we show that intertumoral genetic heterogeneity leads to the simultaneous generation of distinct tumor immune microenvironments within the same mouse. Furthermore, each tumor can independently regulate local PD-1 (programmed cell death protein 1) and PD-L1 (PD-1 ligand) expressions, an immunosuppressive axis targeted by popular checkpoint immunotherapies. This model is useful for furthering the study of intertumoral heterogeneity and of lesion-specific therapeutic responses.

Abstract

Metastatic melanoma portends a poor prognosis and patients may present with multiple, simultaneous tumors. Despite recent advances in systemic immunotherapy, a majority of patients fail to respond, or exhibit lesion-specific responses wherein some metastases respond as others progress within the same patient. While intertumoral heterogeneity has been clinically associated with these mixed lesion-specific therapeutic responses, no clear mechanism has been identified, largely due to the scarcity of preclinical models. We developed a novel murine synchronous melanoma model that recapitulates this intertumoral genetic and microenvironmental heterogeneity. We show that genetic differences between tumors are sufficient to generate distinct tumor immune microenvironments (TIME) simultaneously in the same mouse. Furthermore, these TIMEs lead to the independent regulation of PD-1/PD-L1 (programmed cell death protein 1/PD-1 ligand), a popular axis targeted by immune checkpoint therapy, in response to ongoing anti-tumor immunity and the presence of interferon-gamma. Currently, therapeutic selection for metastatic melanoma patients is guided by a single biopsy, which may not represent the immune status of all tumors. As a result, patients can display heterogeneous lesion-specific responses. Further investigations into this synchronous melanoma model will provide mechanistic insight into the effects of intertumoral heterogeneity and guide therapeutic selection in this challenging patient population.

Immune Checkpoint Inhibitors in Prostate Cancer

Simple Summary

Metastatic prostate cancer is an incurable disease with limited treatment options. Immunotherapy has demonstrated significant success in multiple cancer types but efforts to harness its benefit in prostate cancer have so far largely been unsuccessful. In this review, we analyze the preclinical rationale for the use of immunotherapy and underlying barriers preventing responses to it. We summarize clinical studies evaluating checkpoint inhibitors in prostate cancer. In the end, we review ongoing trials exploring combination immune checkpoint inhibitors in combination with other agents with the intent to modulate the immune system to improve treatment outcomes.

Abstract

Metastatic prostate cancer is a lethal disease with limited treatment options. Immune checkpoint inhibitors have dramatically changed the treatment landscape of multiple cancer types but have met with limited success in prostate cancer. In this review, we discuss the preclinical studies providing the rationale for the use of immunotherapy in prostate cancer and underlying biological barriers inhibiting their activity. We discuss the predictors of response to immunotherapy in prostate cancer. We summarize studies evaluating immune checkpoint inhibitors either as a single agent or in combination with other checkpoint inhibitors or with other agents such as inhibitors of androgen axis, poly ADP-ribose polymerase (PARP), radium-223, radiotherapy, cryotherapy, tumor vaccines, chemotherapy, tyrosine kinase inhibitors, and granulocyte-macrophage colony-stimulating factor. We thereafter review future directions including the combination of immune checkpoint blockade with inhibitors of adenosine axis, bispecific T cell engagers, PSMA directed therapies, adoptive T-cell therapy, and multiple other miscellaneous agents.

Lymphoepithelioma-like Intrahepatic Cholangiocarcinoma Is a Distinct Entity With Frequent pTERT/TP53 Mutations and Comprises 2 Subgroups Based on Epstein-Barr Virus Infection

The molecular characteristics of lymphoepithelioma-like intrahepatic cholangiocarcinoma (LELCC) remain elusive. We examined 27 LELCC cases through next-generation sequencing using a panel of genes commonly mutated in primary liver cancers. Alterations in BAP1, ARID1A, ARID2, and PBRM1 were detected through immunohistochemistry. Fluorescence in situ hybridization was performed to analyze FGFR2 fusions and CCND1 amplification. LELCC is histologically classified as predominantly undifferentiated or glandular. Epstein-Barr virus-encoded small RNA (EBER) expression was found in 16 LELCCs. Approximately 50% of LELCCs expressed programmed death-ligand 1 strongly. Notably, recurrent pTERT and TP53 mutations were detected in 9 (38%) and 8 (33%) tumors, respectively. Only 2 LELCCs exhibited loss of expression for PBRM1. Alterations in genes typically involved in intrahepatic cholangiocarcinoma, including IDH1, IDH2, ARID1A, ARID2, and BAP1, and FGFR2 fusions, were not identified. The 2-step clustering analysis showed 2 distinct subgroups in LELCC, which were separated by EBER expression. A meta-analysis of all reported cases (n=85) has shown that EBER+ LELCC is strongly associated with the female sex, younger age, and exhibited predominantly glandular differentiation (P=0.001, 0.012, and <0.001, respectively). Patients with EBER- LELCC were more likely to have viral hepatitis and cirrhosis (P=0.003 and 0.005, respectively). Genetic analysis demonstrated that EBER- LELCC was significantly associated with pTERT and TP53 mutations (P=0.033 and 0.008, respectively). In conclusion, LELCC is genetically distinct from intrahepatic cholangiocarcinoma. EBER- LELCC may exhibit a different pathogenesis from EBER+ LELCC. High programmed death-ligand 1 expression in LELCC has implications for potential immunotherapeutic strategies.

Find the Flame: Predictive Biomarkers for Immunotherapy in Melanoma

Immunotherapy has revolutionized the therapeutic landscape of melanoma. In particular, checkpoint inhibition has shown to increase long-term outcome, and, in some cases, it can be virtually curative. However, the absence of clinically validated predictive biomarkers is one of the major causes of unpredictable efficacy of immunotherapy. Indeed, the availability of predictive biomarkers could allow a better stratification of patients, suggesting which type of drugs should be used in a certain clinical context and guiding clinicians in escalating or de-escalating therapy. However, the difficulty in obtaining clinically useful predictive biomarkers reflects the deep complexity of tumor biology. Biomarkers can be classified as tumor-intrinsic biomarkers, microenvironment biomarkers, and systemic biomarkers. Herein we review the available literature to classify and describe predictive biomarkers for checkpoint inhibition in melanoma with the aim of helping clinicians in the decision-making process. We also performed a meta-analysis on the predictive value of PDL-1.

Mismatch repair deficiency is rare in bone and soft tissue tumors

Introduction

There has been an increased demand for mismatch repair (MMR) status testing in sarcoma patients after the success of immune checkpoint inhibition (ICI) in MMR deficient tumors. However, data on MMR deficiency in bone and soft tissue tumors is sparse, rendering it unclear if routine screening should be applied. Hence, we aimed to study the frequency of MMR deficiency in bone and soft tissue tumors after we were prompted by two (potential) Lynch syndrome patients developing sarcomas.

Methods

Immunohistochemical expression of MLH1, PMS2, MSH2 and MSH6 was assessed on tissue micro arrays (TMAs), and included 353 bone and 539 soft tissue tumors. Molecular data was either retrieved from reports or microsatellite instability (MSI) analysis was performed. In MLH1 negative cases, additional MLH1 promoter hypermethylation analysis followed. Furthermore, a systematic literature review on MMR deficiency in bone and soft tissue tumors was conducted.

Results

Eight MMR deficient tumors were identified (1%), which included four leiomyosarcoma, two rhabdomyosarcoma, one malignant peripheral nerve sheath tumor and one radiation‐associated sarcoma. Three patients were suspected for Lynch syndrome. Literature review revealed 30 MMR deficient sarcomas, of which 33% were undifferentiated/unclassifiable sarcomas. 57% of the patients were genetically predisposed.

Conclusion

MMR deficiency is rare in bone and soft tissue tumors. Screening focusing on tumors with myogenic differentiation, undifferentiated/unclassifiable sarcomas and in patients with a genetic predisposition / co‐occurrence of other malignancies can be helpful in identifying patients potentially eligible for ICI.

PD-L1 expression in recurrent head and neck squamous cell carcinoma

PURPOSE

To evaluate the Programmed Cell Death Ligand (PD-L1) expression at diagnosis and relapse in patients with head and neck carcinoma (HNSCC) treated with radio(chemo)therapy.

METHODS

PD-L1 immunohistochemistry was performed in tumor cells (TC) and immune cells (IC) in 44 patients and scored as 0 = 0%, 1 =  < 5%, 2 = 6-49% or 3 =  ≥ 50% cells.

RESULTS

PD-L1 expression on TC before RT was scored as 0, 1, 2 and 3 in 28, 4, 8 and 4 patients, respectively. In 10 patients, IC did not show any PD-L1 expression; while in 8, 16, and 10 patients, PD-L1 expression was scored 1, 2 and 3, respectively. At relapse, 7/36 patients had a PD-L1 expression positivation in TC, while the opposite was observed in 6 patients. Overall, survival at 2 years was higher in patients with PD-L1 expression (90% versus 62.5%, p = 0.032).

CONCLUSION

PD-L1 expression may vary throughout the course of the disease. A re-evaluation of PD-L1 expression on biopsies at the time of recurrence should be recommended.

Nanomedicine-based cancer immunotherapies developed by reprogramming tumor-associated macrophages

Tumor microenvironment is a complex ecosystem composed of tumor extracellular matrix, fibroblasts, blood vessels, and immune cells, promoting tumor development by secreting various growth factors, hydrolase, and inflammatory factors. Tumor-associated macrophages (TAMs) constitute the largest number of immune cells in the TME, and they have a "double-edged sword" effect on tumor growth, invasion, metastasis, angiogenesis, and immunosuppression. Under the regulation of different cytokines in the TME, the bidirectional TAMs can switch their phenotypes between tumoricidal M1-like and pro-tumorigenic M2-like macrophages. TAM polarization suggests that scientists can use this property to design drugs targeting this regulation as a promising immunotherapy strategy to enhance tumor therapy efficiency. In this review, we summarize a brief introduction of TAMs and their implications for tumorigenesis. Next, we review recent advances in designing various functionalized nanomedicines and their applications in nanomedicine-based cancer therapies that target TAMs by killing them, inhibiting macrophage recruitment, and repolarizing them from pro-tumorigenic M2-like to tumoricidal M1-like macrophages. Simultaneously, the regulation of nanomedicines on the signaling pathways accounting for these effects is also summarized. This review will not only provide background scientific information for the understanding of TAMs and their roles in cancer treatment but also help scientists design nanomedicines based on tumor TAMs, which can help achieve better clinical treatment outcomes for tumors.

If small molecules immunotherapy comes, can the prime be far behind?

Anti-cancer immunotherapy, which includes cellular immunotherapy, immune checkpoint inhibitors and cancer vaccines, has transformed the treatment strategies of several malignancies in the past decades. Immune checkpoints blockade (ICB) is the most commonly tested therapy and has the potential to induce a durable immune response in different types of cancers. However, all approved immune checkpoint inhibitors (ICIs) are monoclonal antibodies (mAbs), which are fraught with disadvantages including lack of oral bioavailability, prolonged tissue retention and poor membrane permeability. Therefore, the research focus has shifted to developing small molecule inhibitors to obviate the limitations of mAbs. Given the complexity of the tumor micro-environment (TME), the combination of ICIs with various small molecule agonists/inhibitors are currently being tested in clinical trials to improve treatment outcomes and prevent tumor recurrence. In this review, we have summarized the mechanisms and therapeutic potential of several molecular targets, along with the current status of small molecule inhibitors.

The Mechanisms Leading to Distinct Responses to PD-1/PD-L1 Blockades in Colorectal Cancers With Different MSI Statuses

Current clinical studies showed distinct therapeutic outcomes, in which CRC patients with mismatch repair-deficient (dMMR)/microsatellite instability high (MSI-H) seem to be relatively more "sensitive" in response to anti-programmed death-1 receptor (PD-1)/programmed death-1 receptor ligand 1 (PD-L1) therapy than those with mismatch repair-proficient (pMMR)/microsatellite instability-low (MSI-L). The mechanisms by which the same PD-1/PD-L1 blockades lead to two distinct therapeutic responses in CRC patients with different MSI statuses remain poorly understood and become a topic of great interest in both basic research and clinical practice. In this review of the potential mechanisms for the distinct response to PD-1/PD-L1 blockades between dMMR/MSI-H CRCs and pMMR/MSI-L CRCs, relevant references were electronically searched and collected from databases PubMed, MEDLINE, and Google scholar. Sixty-eight articles with full text and 10 articles by reference-cross search were included for final analysis after eligibility selection according to the guidelines of PRISMA. Analysis revealed that multiple factors e.g. tumor mutation burden, immune cell densities and types in the tumor microenvironment, expression levels of PD-1/PD-L1 and cytokines are potential determinants of such distinct response to PD-1/PD-L1 blockades in CRC patients with different MSI statuses which might help clinicians to select candidates for anti-PD-1/PD-L1 therapy and improve therapeutic response in patients with CRC.

Comparing programmed death ligand 1 scores for predicting pembrolizumab efficacy in head and neck cancer

Tumor proportion score (TPS) and combined positive score ([CPS] includes immune cells), 2 methods for scoring programmed death ligand 1 (PD-L1) expression, have been used in clinical trials investigating the immune checkpoint inhibitor pembrolizumab in head and neck squamous cell carcinoma (HNSCC). These trials resulted in regulatory approval for pembrolizumab in the first- and second-line setting outside the United States. We performed a post hoc analysis of the KEYNOTE-040 study (NCT02252042) to determine whether CPS is a practical and suitable alternative scoring method to TPS. In KEYNOTE-040, patients with metastatic HNSCC received pembrolizumab or investigator choice of standard of care (SOC). The relative utility and equivalence of CPS ≥ 50 and TPS ≥ 50% for defining PD-L1 expression status in patients with HNSCC and comparability of scoring methods by tandem receiver operating characteristic (ROC) analysis were analyzed. The cutoff for each method was also evaluated. CPS ≥ 50 appeared equivalent to TPS ≥ 50% for predicting objective response rate (ORR), overall survival, and progression-free survival. ORR for pembrolizumab versus SOC was 26.2 versus 8.5% for TPS ≥ 50%, 28.1 versus 7.7% for CPS ≥ 50, 10.6 versus 11.6% for TPS < 50%, and 10.0 versus 12.0% for CPS < 50. Tandem ROC analysis showed that TPS 50% and CPS 50 maximized delta Youden index and suggested that CPS is more sensitive than TPS at lower cutoffs (i.e., CPS ≥ 1). In conclusion, CPS 50 can be used interchangeably with TPS 50% to determine PD-L1 status in patients with HNSCC. CPS may be more sensitive than TPS at lower cutoffs.

Considerations when treating high-grade pediatric glioma patients with immunotherapy

INTRODUCTION

Children with high-grade gliomas (pHGGs) represent a clinical population in substantial need of new therapeutic options given the inefficacy and toxicity of current standard-of-care modalities. Although immunotherapy has emerged as a promising modality, it has yet to elicit a significant survival benefit for pHGG patients. While preclinical studies address a variety of underlying challenges, translational clinical trial design and management also need to reflect the most updated progress and lessons from the field.

AREAS COVERED

The authors will focus our discussion on the design of clinical trials, the management of potential toxicities, immune monitoring, and novel biomarkers. Clinical trial design should integrate appropriate patient populations, novel, and preclinically optimized trial design, and logical treatment combinations, particularly those which synergize with standard of care modalities. However, there are caveats due to the nature of immunotherapy trials, such as patient selection bias, evidenced by the frequent exclusion of patients on high-dose corticosteroids. Robust immune-modulating effects of modern immunotherapy can have toxicities. As such, it is important to understand and manage these, especially in pHGG patients.

EXPERT OPINION

Adequate integration of these considerations should allow us to effectively gain insights on biological activity, safety, and biomarkers associated with benefits for patients.

The Sarcoma Immune Landscape: Emerging Challenges, Prognostic Significance and Prospective Impact for Immunotherapy Approaches

Simple Summary

Sarcomas are a rare disease with high rates of recurrence and poor prognosis. Important discoveries about the biology of sarcomas have been done during the last decades, without a substantial improvement of systemic treatments. With the agnostic effectivity of immuno-oncological agents in different cancer indications, it is expected that sarcomas can also benefit from these treatments. This article gathers the available data on the specific immune tumor microenvironment of sarcoma and the immunotherapeutic strategies currently under investigation.

Abstract

Despite significant advances in multidisciplinary treatment strategies including surgery, radiotherapy, targeted therapy and chemotherapy there are yet no substantial improvements in the clinical benefit of patients with sarcomas. Current understanding of the underlying cellular and molecular pathways which govern the dynamic interactions between the tumor stroma, tumor cells and immune infiltrates in sarcoma tissues, led to the clinical development of new therapeutic options based on immunotherapies. Moreover, progress of the treatment of sarcomas also depends on the identification of biomarkers with prognostic and predictive values for selecting patients most likely to benefit from these new therapeutic treatments and also serving as potent therapeutic targets. Novel combinations with radiotherapy, chemotherapy, targeted therapy, vaccines, CAR-T cells and treatments targeting other immune components of the tumor microenvironment are underway aiming to bypass known resistance mechanisms. This review focuses on the role of tumor microenvironment in sarcoma, prognosis and response to novel immunotherapies.

Emerging role of SWI/SNF complex deficiency as a target of immune checkpoint blockade in human cancers

Mammalian SWI/SNF complex is a key chromatin remodeler that reshapes nucleosomes and regulates DNA accessibility. Mutations in SWI/SNF subunits are found in a broad spectrum of human cancers; however, the mechanisms of how these aberrations of SWI/SNF complex would impact tumorigenesis and cancer therapeutics remain to be elucidated. Studies have demonstrated that immune checkpoint blockade (ICB) therapy is promising in cancer treatment. Nevertheless, suitable biomarkers that reliably predict the clinical response to ICB are still lacking. Emerging evidence has suggested that SWI/SNF components play novel roles in the regulation of anti-tumor immunity, and SWI/SNF deficiency can be therapeutically targeted by ICB. These findings manifest the prominence of the SWI/SNF complex as a stratification biomarker that predicts treatment (therapeutic) response to ICB. In this review, we summarize the recent advances in ICB therapy by harnessing the cancer-specific vulnerability elicited by SWI/SNF deficiency. We provide novel insights into a comprehensive understanding of the underlying mechanisms by which SWI/SNF functions as a modulator of anti-tumor immunity.

The Role of Immunotherapy in Hepatocellular Carcinoma: A Systematic Review and Pooled Analysis of 2,402 Patients

BACKGROUND

Immune checkpoints inhibitors (ICIs) have emerged as a treatment option for several malignancies. Nivolumab, pembrolizumab, nivolumab plus ipilimumab, and atezolizumab plus bevacizumab have been approved for the management of advanced-stage hepatocellular carcinoma (HCC). We aimed to systematically review the literature and summarize the characteristics and outcomes of patients with HCC treated with ICIs.

METHODS

A systematic literature search of PubMed, the Cochrane Library, and ClinicalTrials.gov was performed according to the PRISMA statement (end of search date: November 7, 2020). Quality of evidence assessment was also performed.

RESULTS

Sixty-three articles including 2,402 patients were analyzed, 2,376 of whom received ICIs for unresectable HCC. Response to ICIs could be evaluated in 2,116 patients; the overall objective response rate (ORR) and disease control rate (DCR) were 22.7% and 60.7%, respectively, and the mean overall survival (OS) was 15.8 months. The ORR, DCR, and OS for nivolumab (n = 846) were 19.7%, 51.1%, and 18.7 months, respectively; for pembrolizumab (n = 435) they were 20.7%, 64.6% and 13.3 months, respectively. The combination of atezolizumab/bevacizumab (n = 460) demonstrated an ORR and DCR of 30% and 77%, respectively. The overall rate of treatment discontinuation because of adverse events was 14.9%. Fifteen patients received ICIs in the liver transplant (LT) setting (one pre-LT for bridging, 14 for post-LT recurrence); fatal graft rejection was reported in 40.0% (n = 6/15) and mortality in 80.0% (n = 12/15).

CONCLUSION

ICIs are safe and effective against unresectable HCC, but caution is warranted regarding their use in the LT setting because of the high graft rejection rate.

IMPLICATIONS FOR PRACTICE

This systematic review pooled the outcomes from studies reporting on the use of immune checkpoint inhibitors (ICIs) for the management of 2,402 patients with advanced-stage hepatocellular carcinoma (HCC), 2,376 of whom had unresectable HCC. The objective response rate and disease control rate were 22.7% and 60.7%, respectively, and the mean overall survival was 15.8 months. The overall rate of treatment discontinuation because of adverse events was 14.9%. Fifteen patients received ICIs in the liver transplant (LT) setting (one pre-LT for bridging, 14 for post-LT recurrence). Six of these patients experienced graft rejection (40.0%).

Nivolumab for the salvage treatment of desperate germ cell tumor: A case report

INTRODUCTION

Testicular germ cell tumors (GCT) are the most common tumor in young men. Their distinctive feature is the exceptional response to platin based combination chemotherapy.Since the prognosis is poor in relapsed and refractory patients, the immune checkpoint inhibitors are candidate agents in these patients although clinical trials are mostly lacking. Herein, we describe a patient with a refractory nonseminomatous GCT using nivolumab as a last resort therapy and provided long term response without any significant toxicity.

CASE REPORT

A 41-year-old male presented with the complaint of flank pain eleven years ago. The patient underwent a retroperitoneal lymph node excision and pathology reported as the mixed germ cell tumor. There were no mass in the testicles and the patient was diagnosed with a primary retroperitoneal GCT. Since the disease has progressed under multiple lines of chemotherapy and autologous stem cell transplantation, treatment was started with nivolumab.

MANAGEMENT AND OUTCOME

The patient started to treatment with nivolumab 3 mg/kg two weekly as a last resort treatment. The nivolumab was continued and the patient's response to this treatment is ongoing and has been stable for 13 months.

DISCUSSION

There are limited treatment options in platinum-refractory germ cell tumors. Recently, immune checkpoint inhibitors tried in this setting with some success in especially non-seminomatous GCTs. We see a good response and prolonged benefit with the use of nivolumab in our patient. Further research including prospective studies on the use of immune checkpoint inhibitors in platinum-resistant testicular cancer can further delineate the role of immunotherapy.

PD-L1 Expression in 65 Conjunctival Melanomas and Its Association with Clinical Outcome

Conjunctival melanoma (CM) iss a rare and aggressive tumour that is increasing in frequency. The prognostic value of PD-L1 expression, alone or in combination with CD8 and PD-1 expression and the BRAF and NRAS status, has not been determined in CM to date. We evaluated the expression of PD-L1, CD8, PD-1 in CM and investigated whether there was an association between the expression of these markers and the BRAF and NRAS molecular profile as well as some clinico-pathological criteria. A total of sixty-five CM were assessed for PD-L1, PD-1, and CD8 expression by immunohistochemistry (IHC) and for BRAF and NRAS genomic alterations using molecular biology techniques and anti-BRAF and anti-NRAS antibodies. PD-L1 expression in tumour cells (TC) was very low or absent but detected in tumour-infiltrating immune cells (IC). A correlation was observed between the expression of PD-L1, CD8, and PD-1 in IC. No correlation between PD-L1 expression (in tumour and/or immune cells) and BRAF or NRAS mutations was observed. PD-L1 expression in IC correlated with a higher pTNM stage and PD-L1 expression in TC with worse disease-specific survival. PD-L1 expression is a potential prognostic biomarker that correlates with poor prognosis in CM patients.

Prognostic value of PD-L1 expression in patients with unresectable stage III non-small cell lung cancer treated with chemoradiotherapy

Background

Expression of PD-L1 is the most investigated predictor of benefit from immune checkpoint blockade in advanced NSCLC but little is known about the association of PD-L1 expression and clinicopathological parameters of patients with unresectable stage III NSCLC.

Methods

National registry data was searched for medical records of consecutive inoperable stage III NSCLC patients treated with ChT and RT from January 2012 to December 2017. Totally 249 patients were identified that met inclusion criteria and of those 117 patients had sufficient tissue for PD-L1 immunohistochemical staining.

Results

Eighty patients (68.4%) expressed PD-L1 of ≥ 1% and 29.9% of more than 50%. Median PFS was 15.9 months in PD-L1 negative patients and 16.1 months in patients with PD-L1 expression ≥ 1% (p = 0.696). Median OS in PD-L1 negative patients was 29.9 months compared to 28.5 months in patients with PD-L1 expression ≥ % (p = 0.888). There was no difference in median OS in patients with high PD-L1 expression (≥ 50%) with 29.8 months compared to 29.9 months in those with low (1–49%) or no PD-L1 expression (p = 0.694). We found that patients who received a total dose of 60 Gy or more had significantly better median OS (32 months vs. 17.5 months, p < 0.001) as well as patients with PS 0 (33.2 vs. 20.3 months, p = 0.005).

Conclusions

In our patients PD-L1 expression had no prognostic value regarding PFS and OS. Patients with good performance status and those who received a total radiation dose of more than 60 Gy had significantly better mOS.

Severe delayed pulmonary toxicity following PD-L1-specific CAR-T cell therapy for non-small cell lung cancer

Objectives

This phase I study aimed to evaluate the antitumor effect and safety of programmed death‐ligand‐1 (PD‐L1)–targeting autologous chimeric antigen receptor T (CAR‐T) cells for patients with non‐small cell lung cancer (NSCLC).

Methods

Programmed death‐ligand‐1–specific CAR‐T cells were generated using lentiviral transduction. Four patients with NSCLC were recruited, but only one patient was finally involved. CAR‐T cells were infused on three different days (total dose during therapy, 1 × 10⁶ CAR‐T cells kg⁻¹ body weight). The date on which the patient received the first CAR‐T cell infusion was designated as Day 0.

Results

Circulating CAR‐T cells accounted for 3.30% of the patient’s peripheral blood T cells detected by FACS analysis during the first follow‐up (Day +29). The chest CT scan showed subtle tumor shrinkage (stable disease). On Day +43, the patient developed pyrexia without any known causes and dyspnoea that rapidly deteriorated to respiratory failure in 3 days. The chest X‐ray and CT scan showed bilateral extensive pulmonary infiltration in addition to the tumor silhouette on the left upper lung. The interleukin (IL)‐6 levels in serum dramatically increased (> 100‐fold). The patient was immediately transferred to the ICU where he received oxygen and intravenous infusions of tocilizumab and methylprednisolone. His symptoms rapidly improved and the pulmonary inflammation gradually resolved.

Conclusion

The clinical manifestations and test findings for this patient with NSCLC might represent unique clinical manifestations of solitary organ damage secondary to PD‐L1–specific CAR‐T cell therapy. The differential diagnosis, underlying mechanism and prevention and treatment strategies for such complications have also been discussed.

PD-L1 Expression and CD8+ Tumor-infiltrating Lymphocytes in Different Types of Tubo-ovarian Carcinoma and Their Prognostic Value in High-grade Serous Carcinoma

The prevalence and significance of programmed death-1 ligand (PD-L1) expression in different types of tubo-ovarian carcinoma have not been well defined. We evaluated PD-L1 expression and CD8 tumor-infiltrating lymphocyte (TIL) density in whole tissue sections of 189 cases of tubo-ovarian carcinoma, including high-grade serous carcinoma (HGSC, n=100), clear cell carcinoma (CCC, n=24), endometrioid carcinoma (EmC, n=40), and mucinous carcinomas (MC, n=25). Using the tumor proportion score (TPS) with a 1% cutoff, PD-L1 expression was present in 21% of HGSC, 16.7% of CCC, 2.5% of EmC, and 4% of MC. Using the combined positive score (CPS) with a cutoff of 1, PD-L1 expression was present in 48% of HGSC, 25% of CCC, 20% of EmC, and 24% of MC. HGSC demonstrated significantly higher CD8 TIL density than CCC (P=0.013238), EmC (P=0.01341), or MC (P=0.004556). In HGSC, CD8 TIL density was directly correlated with PD-L1 positivity using either TPS (P=0.0008) or CPS (P=0.00011). Survival analysis of patients with high stage (stage III to IV) HGSC revealed PD-L1 positivity by TPS to be associated with improved progression-free survival (adjusted hazard ratio: 0.4912 vs. 2.036, P=0.0378). Although not statistically significant, a similar trend was observed in overall survival (adjusted hazard ratio: 0.3387 vs. 2.953, P=0.0548). In contrast, with CPS, no significant difference was identified between PD-L1-positive and negative groups in either progression-free survival (P=0.5086) or overall survival (P=0.7823). Neoadjuvant chemotherapy was associated with higher PD-L1 expression by TPS (P=0.00407) but not CPS. No significant difference in PD-L1 expression was detected in tumors from patients with germline BRCA1/2 mutations compared with germline mutation-negative tumors by either TPS or CPS. In conclusion, the prevalence of PD-L1 expression is variable in different types of tubo-ovarian carcinoma and is highest in HGSC. In high-stage HGSC, PD-L1 positivity in tumor cells is associated with an increased immune response and improved survival.

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.

Immune Expression in Children With Vesicoureteral Reflux: A Pilot Study

OBJECTIVE

To perform an exploratory, descriptive pilot study of the systemic and local immune environment in patients with vesicoureteral reflux (VUR) and bladder-bowel dysfunction (BBD).

METHODS

Consecutive children with VUR undergoing intravesical ureteral reimplantation were enrolled. Patients were assessed for presence of BBD by reported patient history and validated questionnaire. Fresh blood and bladder tissue, collected at the time of surgery, were immediately processed for analysis. Immune cell compositions were determined via flow cytometry. Immune cell activation was also defined at the time of analysis. LegendPlex assay analysis was utilized to define levels of circulating chemokines and cytokines.

RESULTS

A total of 7 patients were enrolled. Although percentages of circulating immune cells in the blood of those with VUR/BBD and VUR alone were similar, within bladder tissue, VUR/BBD demonstrated increased immune infiltrates compared to VUR alone. Bladder sample analysis showed that B cells, and Effector Memory and Naïve T cell percentages were significantly increased in VUR/BBD patients compared to VUR patients. T cell expression of PD1 was increased in bladder tissues of BBD/VUR. Additionally, analysis of circulating neutrophils displayed significantly increased upregulation of PDL-1 in patients with VUR/BBD vs those with VUR only.

CONCLUSION

These pilot data suggest an immune-rich microenvironment is present within VUR. Severity of inflammation appeared to correlate with presence of BBD. This implies that targeting pelvic inflammation may be a novel therapy for children with VUR- or non-VUR-related BBD. Follow-up studies are currently underway.

Immunotherapy Treatment Patterns and Outcomes Among ALK-Positive Patients With Non-Small-Cell Lung Cancer

INTRODUCTION

The treatment landscape for anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC) primarily involves ALK-directed tyrosine kinase inhibitors (TKIs). Although therapy with immune checkpoint inhibitors (ICIs) is a treatment option in NSCLC, the efficacy of ICI is inconclusive in ALK-positive NSCLC as a result of limited data. This retrospective real-world study sought to describe the characteristics of ALK-positive NSCLC patients treated with ICI and to assesses treatment outcomes in US oncology practices.

PATIENTS AND METHODS

This analysis used the Flatiron Health electronic health record-derived deidentified database and included adult (18 years and older) ALK-positive advanced NSCLC patients with receipt of one or more ICIs after January 1, 2015. Median time to ICI discontinuation and real-world progression-free survival (rwPFS) were estimated by Kaplan-Meier methods.

RESULTS

Of 83 patients with ALK-positive NSCLC treated with ICIs, 50.6% (n = 42) received ICI without a prior ALK TKI. Median time to ICI discontinuation was 2.17 months (95% confidence interval, 1.41, 3.32). The median rwPFS was 2.34 months (95% confidence interval, 1.55, 3.09); in patients who received an ICI without prior ALK TKI, it was 3.9 months, and in patients who received ICI therapy after an ALK TKI, it was 1.5 months.

CONCLUSIONS

Real-world effectiveness (rwPFS) of ICIs in ALK-positive NSCLC patients, whether provided before or after TKIs, was limited, underscoring the relative lack of efficacy of ICI in this patient population, particularly compared to approved ALK TKIs.

Assessment for prognostic value of differentially expressed genes in immune microenvironment of clear cell renal cell carcinoma

Tumor-infiltrating immune cells have been recognized to be associated with prognosis and response to immunotherapy; however, genes related to immune microenvironment of clear cell renal cell carcinoma (ccRCC) remains unclear. To better understand the effects of genes involved in immune and stromal cells on prognosis, we used Cancer Genome Atlas Kidney Renal Clear Cell Carcinoma (TCGA-KIRC), DAVID database and ESTMATE algorithm, and divided the patients into low and high groups according to immune (median: 1038.45) and stromal scores (median: 667.945), respectively. We found the immune scores were significantly correlated with clinicopathological parameters and overall survival (OS). Based on immune scores, 890 DEGs were significantly associated with OS among the 1433 up-regulated genes. Based on top 10 DEGs (IL10RA, FCER1G, SASH3, TIGIT, RHOH, IL12RB1, AIF1, LPXN, LAPTM5 and SP140), cases with number of up-regulated genes ≥ 5 were associated poor OS (P = 0.002). In addition, the mean differences of percentages of CD8 T cells (11.32%), CD4 memory resting T cells (-4.52%) and mast resting cells (-3.55%) between low and high immune scores were the most significant. Thus, combination of these genes might use to predict the efficacy of immunotherapy. Further analyses of these genes were warrant to explore their potential association with the prognosis of ccRCC.

Biomarkers for immune checkpoint therapy targeting programmed death 1 and programmed death ligand 1

Rapidly increasing usages of immune checkpoint therapy for cancer treatment, particularly monoclonal antibodies that target programmed cell death-1 (PD-1) and its ligand PD-L1, have been achieved due to startling durable therapeutic efficacy with limited toxicity. The therapeutics significantly prolonged the overall survival and progression free survival of patients across multiple cancer types. However, the objective response rate of patients receiving this kind of treatment is substantially low. Therefore, it is of great importance to exploit reliable biomarkers that can robustly predict the therapeutic effects. Several biomarkers have been characterized for the selection of patients, which is mainly based on immunological and genetic criteria. Herein, we focus on the current progress regarding the biomarkers for anti-PD-1/PD-L1 therapy.

Association of programmed death ligand 1 expression with prognosis among patients with ten uncommon advanced cancers

AIM

PD-L1 expression and high levels of microsatellite instability (MSI-H) may predict response to checkpoint inhibitors, but their prevalence and prognostic value are unknown in many cancers.

METHODS

We retrospectively evaluated PD-L1 combined positive score (CPS) and MSI-H and their association with clinical outcomes among patients with ten advanced uncommon cancers.

RESULTS

398 of 426 patients (93%) had a valid PD-L1 result; most (242; 61%) had CPS ≥1. Prevalence of MSI-H tumors was 8/360. Median overall survival was shorter among patients with PD-L1 CPS ≥1 tumors after first-line treatment (23.0 vs 39.7 months, p = 0.014).

CONCLUSION

PD-L1 was commonly expressed in solid tumors, and CPS ≥1 was associated with shorter overall survival. Prevalence of MSI-H was low.