Vamsidhar Velcheti

Programmed death ligand-1 expression in non-small cell lung cancer

Recent strategies targeting the interaction of the programmed cell death ligand-1 (PD-L1, B7-H1, CD274) with its receptor, PD-1, resulted in promising activity in early phase clinical trials. In this study, we used various antibodies and in situ mRNA hybridization to measure PD-L1 in non-small cell lung cancer (NSCLC) using a quantitative fluorescence (QIF) approach to determine the frequency of expression and prognostic value in two independent populations. A control tissue microarray (TMA) was constructed using PD-L1-transfected cells, normal human placenta and known PD-L1-positive NSCLC cases. Only one of four antibodies against PD-L1 (5H1) validated for specificity on this TMA. In situ PD-L1 mRNA using the RNAscope method was similarly validated. Two cohorts of NSCLC cases in TMAs including 340 cases from hospitals in Greece and 204 cases from Yale University were assessed. Tumors showed PD-L1 protein expression in 36% (Greek) and 25% (Yale) of the cases. PD-L1 expression was significantly associated with tumor-infiltrating lymphocytes in both cohorts. Patients with PD-L1 (both protein and mRNA) expression above the detection threshold showed statistically significant better outcome in both series (log-rank P=0.036 and P=0.027). Multivariate analysis showed that PD-L1 expression was significantly associated with better outcome independent of histology. Measurement of PD-L1 requires specific conditions and some commercial antibodies show lack of specificity. Expression of PD-L1 protein or mRNA is associated with better outcome. Further studies are required to determine the value of this marker in prognosis and prediction of response to treatments targeting this pathway.

Quantitative Assessment of the Heterogeneity of PD-L1 Expression in Non–Small-Cell Lung Cancer

IMPORTANCE Early-phase trials with monoclonal antibodies targeting PD-1 (programmed cell death protein 1) and PD-L1 (programmed cell death 1 ligand 1) have demonstrated durable clinical responses in patients with non-small-cell lung cancer (NSCLC). However, current assays for the prognostic and/or predictive role of tumor PD-L1 expression are not standardized with respect to either quantity or distribution of expression. OBJECTIVE To demonstrate PD-L1 protein distribution in NSCLC tumors using both conventional immunohistochemistry (IHC) and quantitative immunofluorescence (QIF) and compare results obtained using 2 different PD-L1 antibodies. DESIGN, SETTING, AND PARTICIPANTS PD-L1 was measured using E1L3N and SP142, 2 rabbit monoclonal antibodies, in 49 NSCLC whole-tissue sections and a corresponding tissue microarray with the same 49 cases. Non-small-cell lung cancer biopsy specimens from 2011 to 2012 were collected retrospectively from the Yale Thoracic Oncology Program Tissue Bank. Human melanoma Mel 624 cells stably transfected with PD-L1 as well as Mel 624 parental cells, and human term placenta whole tissue sections were used as controls and for antibody validation. PD-L1 protein expression in tumor and stroma was assessed using chromogenic IHC and the AQUA (Automated Quantitative Analysis) method of QIF. Tumor-infiltrating lymphocytes (TILs) were scored in hematoxylin-eosin slides using current consensus guidelines. The association between PD-L1 protein expression, TILs, and clinicopathological features were determined. MAIN OUTCOMES AND MEASURES PD-L1 expression discordance or heterogeneity using the diaminobenzidine chromogen and QIF was the main outcome measure selected prior to performing the study. RESULTS Using chromogenic IHC, both antibodies showed fair to poor concordance. The PD-L1 antibodies showed poor concordance (Cohen κ range, 0.124-0.340) using conventional chromogenic IHC and showed intra-assay heterogeneity (E1L3N coefficient of variation [CV], 6.75%-75.24%; SP142 CV, 12.17%-109.61%) and significant interassay discordance using QIF (26.6%). Quantitative immunofluorescence showed that PD-L1 expression using both PD-L1 antibodies was heterogeneous. Using QIF, the scores obtained with E1L3N and SP142 for each tumor were significantly different according to nonparametric paired test (P < .001). Assessment of 588 serial section fields of view from whole tissue showed discordant expression at a frequency of 25%. Expression of PD-L1 was correlated with high TILs using both E1L3N (P = .007) and SP142 (P = .02). CONCLUSIONS AND RELEVANCE Objective determination of PD-L1 protein levels in NSCLC reveals heterogeneity within tumors and prominent interassay variability or discordance. This could be due to different antibody affinities, limited specificity, or distinct target epitopes. Efforts to determine the clinical value of these observations are under way.

In Situ Tumor PD-L1 mRNA Expression Is Associated with Increased TILs and Better Outcome in Breast Carcinomas

Purpose: Blockade of the PD-1/PD-L1 axis emerged as a promising new therapeutic option for cancer that has resulted in lasting responses in metastatic renal, lung carcinomas, and melanomas. Tumor PD-L1 protein expression may predict response to drugs targeting this pathway. Measurement of PD-L1 protein is limited by the lack of standardized immunohistochemical methods and variable performance of antibodies. Our goal was to correlate PD-L1 mRNA expression with clinical variables in primary breast carcinomas. Experimental Design: The fluorescent RNAscope paired-primer assay was used to quantify in situ PD-L1 mRNA levels in 636 stage I–III breast carcinomas on two sets of tissue microarrays [YTMA128 (n = 238) and YTMA201 (n = 398)]. Tumor-infiltrating lymphocytes (TIL) were assessed by hematoxylin/eosin stain and quantitative fluorescence. Results: On YTMA128 and YTMA201, 55.7% and 59.5% of cases showed PD-L1 mRNA expression, respectively. Higher PD-L1 mRNA expression was significantly associated with increased TILs (P = 0.04) but not with other clinical variables. Elevated TILs (scores 2 and 3+) occurred in 16.5% on YTMA128 and 14.8% on YTMA201 and was associated with estrogen receptor–negative status (P = 0.01 on YTMA128 and 0.0001 on YTMA201). PD-L1 mRNA expression was associated with longer recurrence-free survival (log-rank P = 0.01), which remained significant in multivariate analysis including age, tumor size, histologic grade, nodal metastasis, hormone receptor, HER2 status, and the extent of TILs (HR, 0.268; CI, 0.099–0.721; P = 0.009). Conclusions: PD-L1 mRNA expression is identified in nearly 60% of breast tumors and it is associated with increased TILs and improved recurrence-free survival. These observations support the evaluation of PD-1/PD-L1–targeted therapies in breast cancer. Clin Cancer Res; 20(10); 2773–82. ©2014 AACR.

Sarcomatoid Lung Carcinomas Show High Levels of Programmed Death Ligand-1 (PD-L1)

Programmed death-1 (PD-1) is a coinhibitory inducible receptor present on T-cells and macrophages. Tumor cells with increased programmed death ligand-1 (PD-L1) are believed to escape immunity through activation of PD-1/PD-L1 pathway and suppression of effector-immune responses. Recent strategies targeting the PD-1/PD-L1 axis have shown promising results in patients with several tumors types, including lung carcinomas. Preliminary data suggest that PD-L1 protein expression might have predictive response to such therapies. Sarcomatoid carcinomas (SCs) of the lung include rare subtypes of poorly differentiated non–small-cell lung carcinomas of high grade and aggressive behavior. The biology of these neoplasms is poorly understood and they frequently show increased local inflammatory and lymphocytic infiltration. Here, we report the expression of PD-L1 in 13 SCs from two large retrospective lung cancer cohorts. Using automated quantitative immunofloresence and a mouse monoclonal antibody directed against the extracellular domain of PD-L1, we show that 9 of 13 patients (69.2%) with SCs are positive for PD-L1 and their levels are higher than in conventional non–small-cell lung carcinoma. These results provide rationale for the potential use of targeted immunotherapy in lung SCs.

Evaluation of PD-L1 Expression and Associated Tumor-Infiltrating Lymphocytes in Laryngeal Squamous Cell Carcinoma

Purpose: Programmed death-ligand 1 (PD-L1; also known as CD274 or B7-H1) expression represents a mechanism of immune escape for cancer. Our purpose was to characterize tumor PD-L1 expression and associated T-cell infiltration in primary laryngeal squamous cell carcinomas (SCC). Experimental Design: A well-annotated cohort of 260 operable primary laryngeal SCCs [formalin-fixed paraffin-embedded (FFPE) specimens] was morphologically characterized for stromal tumor-infiltrating lymphocytes (TIL), on hematoxylin/eosin-stained whole sections and for PD-L1 mRNA expression by qRT-PCR in FFPE specimens. For PD-L1 protein expression, automated quantitative protein analysis (AQUA) was applied on tissue microarrays consisting of two cores from these tumors. In addition, PD-L1 mRNA expression in fresh-frozen tumors and normal adjacent tissue specimens was assessed in a second independent cohort of 89 patients with primary laryngeal SCC. Results: PD-L1 mRNA levels were upregulated in tumors compared with surrounding normal tissue (P = 0.009). TILs density correlated with tumor PD-L1 AQUA levels (P = 0.021). Both high TILs density and high PD-L1 AQUA levels were significantly associated with superior disease-free survival (DFS; TILs: P = 0.009 and PD-L1: P = 0.044) and overall survival (OS; TILs: P = 0.015 and PD-L1: P = 0.059) of the patients and retained significance in multivariate analysis. Conclusions: Increased TILs density and PD-L1 levels are associated with better outcome in laryngeal squamous cell cancer. Assessment of TILs and PD-L1 expression could be useful to predict response to immune checkpoint inhibitors. Clin Cancer Res; 22(3); 704–13. ©2015 AACR.

Targeting RET in Patients With RET-Rearranged Lung Cancers: Results From the Global, Multicenter RET Registry

Purpose In addition to prospective trials for non-small-cell lung cancers (NSCLCs) that are driven by less common genomic alterations, registries provide complementary information on patient response to targeted therapies. Here, we present the results of an international registry of patients with RET-rearranged NSCLCs, providing the largest data set, to our knowledge, on outcomes of RET-directed therapy thus far. Methods A global, multicenter network of thoracic oncologists identified patients with pathologically confirmed NSCLC that harbored a RET rearrangement. Molecular profiling was performed locally by reverse transcriptase polymerase chain reaction, fluorescence in situ hybridization, or next-generation sequencing. Anonymized data-clinical, pathologic, and molecular features-were collected centrally and analyzed by an independent statistician. Best response to RET tyrosine kinase inhibition administered outside of a clinical trial was determined by RECIST v1.1. Results By April 2016, 165 patients with RET-rearranged NSCLC from 29 centers across Europe, Asia, and the United States were accrued. Median age was 61 years (range, 29 to 89 years). The majority of patients were never smokers (63%) with lung adenocarcinomas (98%) and advanced disease (91%). The most frequent rearrangement was KIF5B-RET (72%). Of those patients, 53 received one or more RET tyrosine kinase inhibitors in sequence: cabozantinib (21 patients), vandetanib (11 patients), sunitinib (10 patients), sorafenib (two patients), alectinib (two patients), lenvatinib (two patients), nintedanib (two patients), ponatinib (two patients), and regorafenib (one patient). The rate of any complete or partial response to cabozantinib, vandetanib, and sunitinib was 37%, 18%, and 22%, respectively. Further responses were observed with lenvantinib and nintedanib. Median progression-free survival was 2.3 months (95% CI, 1.6 to 5.0 months), and median overall survival was 6.8 months (95% CI, 3.9 to 14.3 months). Conclusion Available multikinase inhibitors had limited activity in patients with RET-rearranged NSCLC in this retrospective study. Further investigation of the biology of RET-rearranged lung cancers and identification of new targeted therapeutics will be required to improve outcomes for these patients.

Incidence of Pneumonitis With Use of Programmed Death 1 and Programmed Death-Ligand 1 Inhibitors in Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis of Trials

Background Programmed death 1 (PD‐1) programmed death‐ligand 1 (PD‐L1) inhibitors show significant clinical activity in non‐small cell lung carcinoma (NSCLC). However, they are often associated with potentially fatal immune‐mediated pneumonitis. Preliminary reports of trials suggest a difference in the rate of pneumonitis with PD‐1 and PD‐L1 inhibitors. We sought to determine the overall incidence of pneumonitis and differences according to type of inhibitors and prior chemotherapy use. Methods MEDLINE, Embase, and Scopus databases were searched up to November 2016. Rates of pneumonitis of any grade and grade ≥ 3 from all clinical trials investigating nivolumab, pembrolizumab, atezolizumab, durvalumab, and avelumab as single agents in NSCLC were collected. The incidence of pneumonitis across trials was calculated using DerSimonian‐Laird random effects models. We compared incidences between PD‐1 and PD‐L1 inhibitors and between treatment naive and previously treated patients. Results Nineteen trials (12 with PD‐1 inhibitors [n = 3,232] and 7 with PD‐L1 inhibitors [n = 1,806]) were identified. PD‐1 inhibitors were found to have statistically significant higher incidence of any grade pneumonitis compared with PD‐L1 inhibitors (3.6%; 95% CI, 2.4%‐4.9% vs 1.3%; 95% CI, 0.8%‐1.9%, respectively; P = .001). PD‐1 inhibitors were also associated with higher incidence of grade 3 or 4 pneumonitis (1.1%; 95% CI, 0.6%‐1.7% vs 0.4%; 95% CI, 0%‐0.8%; P = .02). Treatment naive patients had higher incidence of grade 1 through 4 pneumonitis compared with previously treated patients (4.3%; 95% CI, 2.4%‐6.3% vs 2.8%; 95% CI, 1.7%‐ 4%; P = .03). Conclusions There was a higher incidence of pneumonitis with use of PD‐1 inhibitors compared with PD‐L1 inhibitors. Higher rate of pneumonitis was more common in treatment naive patients.

High SOX2 Levels Predict Better Outcome in Non-Small Cell Lung Carcinomas

Background SOX2 is an embryonic developmental transcription factor, which is important in the development of the respiratory tract. SOX2 overexpression is associated with aggressive disease in several tumor types. However, SOX2 overexpression and gene amplification associates with favorable outcome in lung squamous cell carcinomas (SCC) and dissimilar results have been reported in lung adenocarcinomas (ADC). The aim of the present study was to evaluate SOX2 expression in NSCLC and determine the relationship with clinico-pathological variables and outcome. Methods SOX2 protein levels were measured in tissue microarrays (TMAs) containing FFPE samples from two independent lung cancer cohorts (n = 340 & 307) using automated quantitative immunofluorescence (QIF). Assay validation was performed using FFPE preparations of cell lines with known SOX2 expression. Associations of SOX2 levels with main clinico-pathological characteristics and with overall survival were studied using uni-and multivariate analysis. Results SOX2 levels were higher in patients with SCC than in ADC in both cohorts (p value<0.0001). In the training cohort, NSCLC patients whose tumors showed high SOX2 (n = 245) had longer survival than those with low SOX2 levels (log rank p = 0.0002). Comparable results were observed in the second independent validation cohort, log rank p = 0.0113. SOX2 positive cases showed a 58% reduction in risk of death in Cox univariate analysis (hazards ratio-HR = 0.42 confidence interval-CI (0.36,0.73), p = 0.0002). SOX2 was associated with significantly longer survival independent of histology in multivariate analysis (hazards ratio-HR = 0.429 confidence interval-CI (0.295, 0.663), p = <0.001). Conclusions SOX2 is an independent positive prognostic marker in NSCLC. Increased SOX2 levels are more frequent in SCC than in ADC, but the association with better survival is independent from the histological subtype.

Incidence of pneumonitis with use of PD-1 and PD-L1 inhibitors in non-small cell lung cancer: A Systematic Review and Meta-analysis of trials

Background Programmed death 1 (PD‐1) programmed death‐ligand 1 (PD‐L1) inhibitors show significant clinical activity in non‐small cell lung carcinoma (NSCLC). However, they are often associated with potentially fatal immune‐mediated pneumonitis. Preliminary reports of trials suggest a difference in the rate of pneumonitis with PD‐1 and PD‐L1 inhibitors. We sought to determine the overall incidence of pneumonitis and differences according to type of inhibitors and prior chemotherapy use. Methods MEDLINE, Embase, and Scopus databases were searched up to November 2016. Rates of pneumonitis of any grade and grade ≥ 3 from all clinical trials investigating nivolumab, pembrolizumab, atezolizumab, durvalumab, and avelumab as single agents in NSCLC were collected. The incidence of pneumonitis across trials was calculated using DerSimonian‐Laird random effects models. We compared incidences between PD‐1 and PD‐L1 inhibitors and between treatment naive and previously treated patients. Results Nineteen trials (12 with PD‐1 inhibitors [n = 3,232] and 7 with PD‐L1 inhibitors [n = 1,806]) were identified. PD‐1 inhibitors were found to have statistically significant higher incidence of any grade pneumonitis compared with PD‐L1 inhibitors (3.6%; 95% CI, 2.4%‐4.9% vs 1.3%; 95% CI, 0.8%‐1.9%, respectively; P = .001). PD‐1 inhibitors were also associated with higher incidence of grade 3 or 4 pneumonitis (1.1%; 95% CI, 0.6%‐1.7% vs 0.4%; 95% CI, 0%‐0.8%; P = .02). Treatment naive patients had higher incidence of grade 1 through 4 pneumonitis compared with previously treated patients (4.3%; 95% CI, 2.4%‐6.3% vs 2.8%; 95% CI, 1.7%‐ 4%; P = .03). Conclusions There was a higher incidence of pneumonitis with use of PD‐1 inhibitors compared with PD‐L1 inhibitors. Higher rate of pneumonitis was more common in treatment naive patients.

Checkpoint immunotherapy: good for cancer therapy, bad for rheumatic diseases

The goal of harnessing the immune system to fight cancer is not new; it dates back 125 years to when William Coley advocated that the bodys response to infection could have anti-tumoural effects.1 However, decades of efforts using vaccines and immune stimulant therapies to harness the immune system to fight tumours have had limited success and at times have been fraught with serious adverse outcomes. Recently, drugs blocking negative immune checkpoint pathways have shown remarkable clinical activity in various solid tumours.2 Several agents targeting two such negative checkpoints, the programmed death-1 (PD-1) pathway (pembrolizumab, nivolumab and atezolizumab) and the cytotoxic T-lymphocyte-associated protein 4 (CTLA4) (ipilimumab) are currently Food and Drug Administration and European Medicines Agency approved. These negative checkpoint pathways play a role in immune tolerance in normal tissues and the activation of these pathways is largely contextual. While these therapies have added immeasurably to the longevity of many patients with malignancies, they have come at a cost with the development of numerous untoward autoimmune inflammatory conditions. The anti-tumour mechanism for checkpoint inhibitor therapies is incompletely understood but clearly relates to the manipulation of T-cell pathways involved in cellular activation and deactivation.2 T-cell homeostasis is a tightly choreographed process whereby naive T cells rapidly proliferate in a logarithmic fashion when effectively activated and then contract following successful defeat of the challenge. CD4 T-cell activation canonically requires two signals: a primary signal ( signal 1 ), mediated by recognition of cognate antigen by the T-cell receptor via presentation by self-major histocompatibility complex class II molecules on the antigen-presenting cell, and a secondary signal ( signal 2 ), mediated by CD28 on the T-cell, binding its ligand partner of the B7 family on the antigen-presenting cell.3 Of vital importance to the host is the integration of deactivating pathways or checkpoints leading to contraction …