High Levels Of PD-L1 Expression Research Articles

The average copy number variation (CNVA) of chromosome fragments is a potential surrogate for tumor mutational burden in predicting responses to immunotherapy in non-small-cell lung cancer.

ObjectivesThe tumor mutational burden (TMB) is closely related to immunotherapy outcome. However, the cost of TMB detection is extremely high, which limits its use in clinical practice. A new indicator of genomic instability, the average copy number variation (CNVA), calculates the changes of 0.5‐Mb chromosomal fragments and requires extremely low sequencing depth.MethodsIn this study, 50 samples (23 of which were from patients who received immunotherapy) were subjected to low‐depth (10X) chromosome sequencing on the MGI platform. CNVA was calculated by the formula avg (abs (copy number‐2)). In addition, CNVA and TMB were compared with regard to their ability to predict immune infiltration in 509 patients from TCGA.ResultsThe high‐CNVA group had higher expression levels of PD‐L1, CD39 and CD19 and a higher degree of infiltration of CD8+ T cells and CD3 + T cells. Among the 23 patients treated with immunotherapy, the average CNVA value of the stable disease/partial response group was higher than that of the progressive disease group (P < 0.05). Whole‐genome sequencing data of 509 patients from TCGA and RT‐PCR results of 22 frozen specimens showed that CNVA is more effective than TMB in indicating infiltration of CD8+ T cells and expression of PD‐L1, and CNVA also showed a specific positive correlation with TMB (r = 0.2728, P < 0.0001).ConclusionsCopy number variation can be a good indicator of immune infiltration and immunotherapy efficacy, and with its low cost, it is expected to become a substitute for TMB.

The impact of ARID1A mutation on molecular characteristics in colorectal cancer.

ARID1A is a key subunit of the SWItch/Sucrose Non-Fermentable (SWI/SNF) complex which regulates dynamic repositioning of nucleosomes to repair DNA damage. Only small pilot studies have evaluated the role of ARID1A mutation in colorectal cancer (CRC). The aim of the present study was to explore the potential impact of ARID1A mutation on clinicopathological and molecular characteristics in CRC. We used integrated data sets of 7978 CRC cases (one data set from a clinical laboratory improvement amendments [CLIA]-certified laboratory and three independent published data sets). The associations of ARID1A mutation with molecular characteristics including immune profile (the status of microsatellite instability [MSI], tumour mutational burden [TMB], programmed death ligand 1 [PD-L1] and estimated infiltrating immune cells), clinicopathological featuresand related pathways were analysed using next-generation sequencing, RNA sequencingand immunohistochemistry. ARID1A mutant samples had more genomically unstable tumour features (MSI-high and TMB-high) and exhibited more characteristics of a T-cell-inflamed microenvironment (PD-L1 expressionand high estimated infiltrating cytotoxic T lymphocytes [CTLs]) than ARID1A wild-type samples in the discovery and validation cohorts. Even ARID1A mutant samples without MSI-high status were TMB-high, had high levels of PD-L1 expressionand high estimated infiltrating CTLs. ARID1A mutations were more common with right-sided primary and earlier stage tumours. ARID1A mutant tumours mainly had co-occurring gene mutations related to chromatin modifying, DNA repair, WNT signalling and epidermal growth factor receptor inhibitor resistance pathways, and ARID1A mutations strongly regulated DNA repair pathways. Key genes for chemotherapy/radiotherapy sensitivity were suppressed in ARID1A mutant samples. Our findings may provide novel insights to develop individualised approaches for treatment of CRC based on ARID1A mutation status.

Integrative assessment of clinicopathological parameters and the expression of PD-L1, PD-L2 and PD-1 in tumor cells of retroperitoneal sarcoma.

Evidence is limited regarding the immunologic profile and immune microenvironment of soft tissue sarcoma subtypes. The aim of the present study was to describe the clinical significance and prognostic implications of PD-L1, PD-L2, and PD-1 in patients with retroperitoneal sarcoma (RSar). In this retrospective, multicenter, collaborative study, medical charts were reviewed and the immunohistochemical staining results of resected tissue specimens from 51 patients with RSar were examined. Immunohistochemical staining was performed with primary antibodies against PD-L1, PD-L2, PD-1, and Ki-67. The correlations between the baseline clinical parameters and expression levels of the four molecules in sarcoma cells were evaluated, and their prognostic values after tumor resection were assessed. Dedifferentiated liposarcoma (41%), leiomyosarcoma (20%), and undifferentiated pleomorphic sarcoma (16%) were the three major types identified. Dedifferentiated liposarcoma and leiomyosarcoma showed higher levels of PD-L1 expression than did other sarcomas. The Spearman correlation analysis revealed that baseline serum lactate dehydrogenase levels were moderately and positively correlated with PD-L1 (P=0.02, r=0.41) and PD-L2 (P=0.006, r=0.47) expression. The median recurrence-free and disease-specific survival was 58 and 16 months, respectively, during the 29-month median follow-up after surgery. On univariate analysis, a higher expression level of PD-1 was associated with a higher risk of recurrence, whereas multivariate analyses revealed that independent predictors of recurrence-free and disease-specific survival indicated a high expression of Ki-67 (P=0.03; hazard ratio, 2.29 vs. low expression) and prognostic stage IIIB (P=0.04; hazard ratio, 5.11 vs. stage I–II), respectively. Findings of the current study provide novel insights about the prognostic value of PD-L1, PD-L2, and PD-1 expression in RSar. Serum lactate dehydrogenase levels constitute a potential predictor of PD-L1 and PD-L2 expression levels in RSar. Further investigations are needed to determine the immunologic landscape of RSar and provide a foundation for therapeutic intervention using immune checkpoint inhibitors.

The frequency and inter-relationship of PD-L1 expression and tumour mutational burden across multiple types of advanced solid tumours in China

BackgroundPD-L1 expression and tumour mutational burden (TMB) are both associated with the responses of multiple tumours to immune checkpoint inhibitor (ICI) therapy. However, their prevalence and correlations may differ in different types of advanced solid tumours.MethodsPD-L1 expression, TMB, and PD-1+ Tils (tumour-infiltrating lymphocytes) infiltration and their relationships were assessed in 6668 advanced solid tumour specimens across 25 tumour types. CD8+ T cell infiltration was analysed in 347 NSCLC samples. The associations of these biomarkers with the therapeutic effect of PD-1 inhibitor were analysed in a cohort of NSCLC samples.ResultsPD-L1 expression levels and TMB in different tumour types varied widely and their relationship was not significantly correlated in most cancer types, with only a small association across all specimens (Spearman R = 0.059). PD-1+ Tils infiltration was positively correlated with PD-L1 expression across all samples (Spearman R = 0.3056). However, there is no such correlation between PD-1+ Tils infiltration and TMB. In NSCLC samples, CD8+ T cell infiltration was correlated with PD-1+ Tils infiltration and PD-L1 expression but not with TMB (Spearman R = 0.4117, 0.2045, and 0.0007, respectively). Patients in the CR/PR group (anti-PD-1 therapy) had higher levels of PD-L1 expression, TMB, PD-1+ Tils, and CD8+ T cell infiltration, and many patients in this group exhibited concomitantly elevated levels of multiple biomarkers.ConclusionsOur results showed the PD-L1 expression status and TMB in various types of advanced solid tumours in Chinese patients and their relationships with PD-1+ Tils and CD8+ T cell infiltration, which may inform ICI treatment.

A phase II, randomized study of nivolumab (NIVO), NIVO plus linrodostat mesylate, or NIVO plus intravesical bacillus Calmette-Guerin (BCG) in BCG-unresponsive, high-risk, nonmuscle invasive bladder cancer (NMIBC): CheckMate 9UT.

TPS5090 Background: Immune checkpoint inhibitors, including NIVO (anti–PD-1), have demonstrated favorable tolerability and efficacy profiles, ushering in a new treatment (tx) paradigm for advanced bladder cancer (advBC). However, an unmet need exists for new effective tx options in earlier stages of disease, specifically for patients (pts) with BCG-unresponsive, high-risk NMIBC. Increased IDO and PD-L1 expression in NMIBC tumors (Inman, et al. Cancer 2007; Hudolin, et al. Anticancer Res 2017), support the combination of anti–PD-1 and IDO1 inhibition in NMIBC. Linrodostat mesylate, a selective, potent, once-daily IDO1 inhibitor, has demonstrated clinical activity in combination with NIVO in pts with immunotherapy-naive advBC who received ≥ 1 prior line of therapy (objective response rate, 37%; Tabernero, et al. J Clin Oncol 2018;36(suppl) [abstr 4512]). Furthermore, high levels of PD-L1 expression have been reported in patients not responding to BCG tx. These findings provide a rationale for investigation of NIVO ± linrodostat ± intravesical BCG therapy in BCG-unresponsive high-risk NMIBC. Here we describe a phase 2, randomized, open-label study assessing the safety and efficacy of NIVO ± linrodostat ± intravesical BCG in pts with BCG-unresponsive, high-risk NMIBC (NCT03519256). Methods: Pts aged ≥ 18 years with BCG-unresponsive (per February 2018 FDA guidance), high-risk NMIBC, defined as carcinoma-in-situ (CIS) with or without papillary component, any T1, or Ta high-grade lesions, will be enrolled. Pts must have urothelial carcinoma as the predominant histological component ( &gt; 50%). Key exclusion criteria include locally advanced or metastatic BC, upper urinary tract disease within 2 years, prostatic urethral disease within 1 year, and prior immunotherapy. Using a novel adaptive-type design, pts will be randomized to 1 of 4 tx arms with NIVO ± linrodostat ± BCG. Primary endpoints include proportion of pts with CIS with complete response (CR) and duration of CR in pts with CIS. Secondary endpoints are progression-free survival and safety. This global study in 14 countries is underway, with a target enrollment of 436 pts. Clinical trial information: NCT03519256 .

Tumor-targeted oncolytic adenovirus demonstrates high cytotoxicity for human lung and renal cell carcinomas independently of the level of tumor PD-L1 expression.

3596 Background: Immuno-checkpoint (IC) inhibitors targeting PD1-PD-L1 pathway have proven highly effective at extending survival of cancer patients. However, the clinical benefits of IC inhibitors are limited to only about 20% patients who have moderate to high levels of tumor PD1 and/or PD-L1 expression. To develop therapeutics that would provide clinical benefits to a larger proportion of cancer patients, we engineered oncolytic adenovirus for targeted infection of human tumor cells via CD46 and integrins of α3β1 or α6β4 classes, overexpressed on many epithelial human cancers. Methods: Here, we analyzed the infectivity and cytotoxicity of this novel oncolytic virus in a panel of human non-small cell lung cancers (NCSLC) cell lines, primary patient derived NSCLC xenografts, and tumor surgical explants from patients with renal cell carcinoma (RCC). Results: The in vitro analysis of NSCLC cells lines (N = 17) demonstrated that over 60% of them were highly sensitive to virus infection. The genome-wide transcriptional profiling showed that only 3 out of 12 cell lines that were sensitive to oncolytic virus infection, expressed PD-L1 ( &gt; 4.5 Log2 RPMK). Furthermore, although the pre-treatment of these cell lines with IFN-I activated PD-L1 expression, IFN-I treatment did not reduce the efficacy of tumor cell infection by the oncolytic virus. The analysis of virus infectivity on primary human tumor cells from patients with NSCLC (N = 4) and RCC (N-24) demonstrated that primary tumors were highly sensitive to oncolytic virus infection. Specifically, tumor-targeted oncolytic virus demonstrated strong cytotoxicity in 22 out of 24 analyzed primary isolated RCC cell samples. Next, we subcutaneously grafted PD-L1-negative NSCLC A549 cells to NSG mice, treated them with oncolytic virus intravenously, and the kinetics of tumor growth and animal survival was monitored. This analysis showed that after intravenous administration, oncolytic virus was able to infect tumor cells and suppress tumor growth. Whereas the median survival in mock-treated group was 26 days, all mice survived up to 100 days post oncolytic virus therapy (endpoint). Conclusions: Our study showed that tumor-targeted oncolytic adenovirus infects human tumor cell lines independently of their PD-L1 expression status and is not sensitive to IFN-I inhibition. This novel tumor-targeted oncolytic virus has the potential to provide clinical benefits to cancer patients, who do not respond or became resistant to ICI drugs.

PD-1 or PD-L1 co-localizes with immune cells for prediction of prognosis in non-small cell lung cancer.

e21029 Background: A number of studies have shown that tumor cells expressing PD-L1 correlate with a better prognosis of immunotherapy in patients with non-small cell lung cancer(NSCLC). However, there were few studies on the immune cells that expressing PD-1 or PD-L1 affect the clinical outcome of patients with NSCLC. Therefore, further research is needed Methods: A total of 336 tumor tissues from patient with non-small cell lung cancer were collected and divided into two cohorts, discovery cohort (174 patients) and validation cohort (162 patients). We used multiplex IHC to identify and quantify CD8, CD57, CD68, CD163, PD-1 and PD-L1 positive rate in tumor tissues, and analyzed its relationship with clinical prognosis. Results: Both PD-1 and PD-L1 were detected on CD8+, CD57+, CD68+, and CD163+ immune cells, but the positive rate were different. PD-1 was higher on cytotoxic T cells (CD8+PD-1+) and PD-L1 was higher on macrophages and cytotoxic T cells (CD68+PD-L1+ and CD8+PD-L1+). By undifferentiated clustering analysis in discovery cohort, the survival rate of tumors with more immune cells expressing PD-1 or PD-L1 was worse. Univariate analysis using X-tile plots to generate the optimum cut off score for all features revealed that immune cells expressing PD-1 or PD-L1 were adverse factors of clinical prognosis of patients with NSCLC, and this result was also confirmed in the validation cohort. Conclusions: In 336 non-small cell lung cancer cases, the expression characteristics of PD-1 and PD-L1 on tumor-infiltrating immune cells were related to survival of patient. In this study, high level of PD-1 and PD-L1 expression on immune cells were associated with lower survival rate, and biomarker characteristics based on this analysis probably enables us to better guide clinical treatment

Immunofocus-PD-L1 high throughput quantitative next generation sequencing assay.

e13521 Background: Immunohistochemical (IHC) assays are presently used as the gold standard predictive tests for immunotherapy but are compromised due to a number of potential variables. Comparative studies have demonstrated differing levels of PD-L1 staining between assays which appears independent of the antibody binding epitope. Secondly, inter-reader reliability even between expert pathologists is problematic particularly for assessment of PD-L1 positive immune cell populations. Methods: To improve predictive testing for anti PD-L1/PD1 immunotherapies we have developed and validated a Next Generation Sequencing Platform, Immunofocus, able to perform high-throughput quantitative PD-L1 gene expression levels in routine diagnostic PWET biopsies. We applied Immunofocus to a cohort of 130 NSCLCs and compared PD-L1 gene expression levels with PD-L1 IHC scores generated using the VENTANA PD-L1 (SP142) Assay. The PD-L1 IHC assessment was carried out double blinded by an independent laboratory. PD-L1 IHC scores were calculated using an algorithm combining tumour proportion score (TPS) with a PD-L1 positive immune cell (IC) score and immune cell area. Results: An exceptionally high degree of correlation was observed between the NGS PD-L1 levels with the combined PD-L1 IHC scores (P &lt; 0.001). Therapeutic cut points for NGS PD-L1 levels were identified corresponding to PD-L1 IHC defined clinical cut points. Notably, ~20% of patients with negative PD-L1 IHC scores showed high NGS PD-L1 expression levels. We hypothesize that these cases represent false negatives and identify a cohort of patients who have shown significant response rates to anti-PD-L1/PD-directed immunotherapies. Conclusions: The Immunofocus NGS PD-L1 assay has potential to greatly improve patient selection for immunotherapy by removing the IHC assay variables and inter-reader variability which compromise current PD-L1 IHC tests while also providing standardized high throughput in the clinical setting. Immunofocus is able to integrate gene expression with somatic mutation analysis allowing capture of networks regulating the immune-checkpoint including for example adaptive and innate resistance pathways, JAK1/2 pathways, differential MHC expression, TEFF gene signature, neoantigen surrogates such as DDR defects and TMB. The integration of NGS PD-L1 expression with other putative biomarkers of response is presently ongoing to further improve prediction of response.

Nab-paclitaxel and atezolizumab for the treatment of PD-L1-positive, metastatic triple-negative breast cancer: review and future directions

ABSTRACTIntroduction: Breast cancer is the most common malignancy in women in the United States and triple-negative breast cancer (TNBC) accounts for 15–20%. The standard of care for metastatic TNBC has been limited to cytotoxic chemotherapy with modest efficacy. TNBC is associated with high levels of tumor-infiltrating lymphocytes and PD-L1 expression, supporting the investigation of immune checkpoint inhibitors in this breast cancer subtype.Areas covered: This review summarizes the clinical data supporting the use of atezolizumab and nab-paclitaxel in the treatment of metastatic PD-L1-positive TNBC. It examines the pharmacology and toxicity profile of the combination in patients with metastatic TNBC.Expert opinion: The addition of atezolizumab to nab-paclitaxel prolonged progression-free survival in both the intention-to-treat and PD-L1-positive subgroups in the first-line setting in patients with metastatic TNBC. The IMpassion 130 trial led to FDA-approval of this combination in patients with PD-L1-positive, metastatic TNBC and represents the first approval of immunotherapy for TNBC. This work supports ongoing investigations of other immunotherapy combinations in TNBC, predictive biomarker development, and immunotherapy in patients with early-stage TNBC. Immunotherapy combinations in TNBC have the potential to lead to improved survival in this group of patients with high-risk disease.

PD-L1 expression, tumor mutational burden, and microsatellite instability status in 746 pancreas ductal adenocarcinomas.

757 Background: Pancreas ductal adenocarcinomas (PDA) has a 5-year survival rate of 6% with a need for new therapeutic options. The approval of pembrolizumab for some gastrointestinal cancers shows the potential of immunotherapy (IMT) in PDA. We evaluated the IMT-associated biomarkers of PD-L1 expression, tumor mutational burden (TMB), microsatellite instability (MSI) and PD-L1 amplification in PDAs. Methods: 746 formalin-fixed paraffin embedded samples were evaluated for PD-L1 IHC using the Dako 22C3 pharmDx assay and scored using tumor proportion score (TPS). The cases had comprehensive genomic profiling (CGP) via DNA sequencing, using a hybrid-capture next-generation sequencing assay (FoundationOne and FoundationOneCDx) for genomic alterations (GAs), TMB, and MSI. Results: PD-L1 was positive (TPS ≥ 1%) in 29% (214/746) and negative in 71% (532/746). 43/214 (20%) of positive cases were high positive (TPS ≥ 50%). TMB (590 cases) had a mean of 3.20, 3.46, and 3.61 mutations/Mb for PD-L1 negative, positive, and high positive groups. 3 hypermutated (TMB ≥ 20) were negative for PD-L1 expression. 3/581 cases were MSI-high with a high TMB score (average 23.53 mutations/Mb). 2 MSI-high cases were negative for PD-L1 and 1 was high positive. PD-L1 amplification was not detected (0/746). Only BCOR was significantly different between PD-L1 high positive and PD-L1 negative tumors (Table). Conclusions: Of 729 PDA cases, 29% were positive (TPS ≥ 1%) for PD-L1 expression while only 6% of all cases showed a high level of PD-L1 expression on tumor cells. TMB high (3/729) and MSI-High (3/729) cases were rare. Only 2 of the TMB high cases were also MSI-high. PD-L1 amplification was not detected. Comparing GAs in PD-L1 high positive vs negative cases was only significantly different for BCOR. Further investigation is needed to see if a combined positive score of PD-L1 expression may identify a subset of patients with PDA who are more likely to respond to IMT. [Table: see text]

Whole transcriptome analysis of gestational trophoblastic neoplasms reveals altered PI3K signaling pathway in epithelioid trophoblastic tumor

ObjectiveGenomic characteristics of gestational trophoblastic neoplasm (GTN) are mostly unknown. This study reveals the molecular features of malignant GTN, including choriocarcinoma (CC), epithelioid trophoblastic tumor (ETT), and placental site trophoblastic tumor (PSTT), by whole transcriptome sequencing analysis. MethodsData obtained from the total RNA sequencing of 2 CC, 4 ETT, and 4 PSTT were evaluated for differential gene expression, pathway alteration, fusion gene, infiltrating immune cell type, PD-L1 and PTEN expression level, and mutation analysis was performed. ResultsThe transcriptome data were correlated with known biomarkers, including HDS3B1, p63, hCG, and hPL for all tumor types. ETT and PSTT were more closely clustered compared with CC in clustering analysis using gene expression; however, ETT showed various altered signaling pathways, including PI3K-Akt-mTOR, with frequent loss of PTEN protein expression. This finding was both well correlated with PIK3CA c.3140A > G pathogenic mutation, detected in 1 ETT, and further confirmed using the MassARRAY method. PSTT showed an overexpressed gene cluster associated with muscle contraction and G protein-coupled receptor activity. No significant fusion gene was seen in all 10 cases. In tumor-infiltrating immune cell profiles, CD4 memory T cell and macrophage signature were relatively high in ETT and PSTT. PD-L1 mRNA expression level was high in all cases, which was significantly correlated with the PD-L1 level by immunohistochemistry (p = 0.03) with positivity in all 10 cases. ConclusionsETT and PSTT were similar at the transcriptome level, with a high level of PD-L1 expression in all tumor types; however, specific pathways, such as PI3K signaling, were altered in ETT.

Retrospective analysis of the prognostic value of PD-L1 expression and 18F-FDG PET/CT metabolic parameters in colorectal cancer.

Background: It has been rarely reported whether 18F-fluorodeoxyglucose (18F-FDG) uptake in colorectal cancer cells is associated with the expression of PD-L1. We performed a clinical pathology study to evaluate PD-L1 expression in patients undergoing surgical resection of colorectal cancer with preoperative 18F-FDG PET/CT imaging, with the aim of predicting the response of CRC patients to immune checkpoint inhibitors.Material and Methods: A retrospective analysis of patients with CRC who underwent FDG-PET imaging before surgery was performed to measure the parameters of FDG-PET imaging: the maximum standardized uptake value (SUVmax), the metabolic tumor volume (MTV), and the total lesion glycolysis (TLG) were evaluated to determine whether each parameter was associated with clinical pathology. Tumor specimens were subjected to PD-L1 staining by immunohistochemistry. Analysis of whether there is a correlation between PD-L1 expression and 18F-FDG uptake parameters in CRC.Results: PD-L1 expression level was significantly correlated with SUVmax, MTV3.0 and TLG3.0. Multivariate analysis showed that PD-L1 and TLG3.0 were independent predictors of poor DFS in patients with CRC (P=0.009; P=0.016), PD-L1 expression is closely related to the patient's lesion (TLG3.0) (P<0.01).Conclusion: The results of this study indicate that there was a significant correlation between PD-L1 expression and TLG3.0 which suggested that FDG-PET could serve as a noninvasive tool to assess the tumor microenvironment and as a predictor of PD-L1 inhibitor activity to determine the optimal therapeutic strategy for CRC. High PD-L1 expression levels and high TLG3.0 are independent risk factors for DFS differences in CRC patients.

Amplification of 9p24.1 in diffuse large B-cell lymphoma identifies a unique subset of cases that resemble primary mediastinal large B-cell lymphoma

Copy number alterations (CNAs) of 9p24.1 occur frequently in Hodgkin lymphoma, primary mediastinal large B-cell lymphoma (PMBCL), primary central nervous system lymphoma, and primary testicular lymphoma, resulting in overexpression of PD-L1 and sensitivity to PD-1 blockade-based immunotherapy. While 9p24.1 CNA was also reported in diffuse large B-cell lymphoma (DLBCL), little is known about its molecular or clinical significance. In this study, we analyzed the prevalence of 9p24.1 CNA in newly diagnosed DLBCL and examined its association with PD-L1, PD-L2, and JAK2 expression, clinical characteristics, and outcome. We found that 10% of DLBCL cases had CNA of 9p24.1, with 6.5% gains, and 3.5% amplifications. Only the cases with a 9p24.1 amplification had high levels of PD-L1, PD-L2, and JAK2 expression. Gains or amplifications of 9p24.1 were associated with a younger age and the ABC/non-GCB subtype. Compared with DLBCL cases without 9p24.1 CNA, the cases with a 9p24.1 amplification had a trend of better event-free survival. Furthermore, the amplification cases had a gene expression and mutation profile similar to those of PMBCL. Our data suggest that amplification of 9p24.1 identifies a unique subset of DLBCL with clinical and molecular features resembling PMBCL that may be amenable to PD-1 blockade-based immunotherapy.

Abstract CT164: A Phase II clinical trial of GVAX pancreas vaccine (with Cyclophosphamide) in combination with Nivolumab and Stereotactic Body Radiation Therapy (SBRT) followed by definitive resection for patients with borderline resectable pancreatic adenocarcinoma (BR-PDAC)

Abstract Background: A strong rationale exists for the use of preoperative therapy in BR-PDAC, because upfront surgery in these patients results in a high probability of incomplete resection. Recently, the Alliance A021101 trial, which utilized neoadjuvant FOLFIRINOX and chemoradiation, demonstrated the safety and clinical activity of neoadjuvant therapy in BR-PDAC. The present clinical trial will evaluate the safety and clinical activity of neoadjuvant Stereotactic Body Radiation Therapy (SBRT) in combination with neoadjuvant cyclophosphamide (Cy)/GVAX pancreas vaccine/nivolumab immunotherapy after completion of standard chemotherapy in patients with BR- PDAC. GVAX is an allogeneic, whole-cell, GM-CSF-secreting vaccine that induces T-cell immunity against tumor-associated antigens. GVAX has previously been studied in combination with low-dose Cy to inhibit regulatory T cells. In prior studies, neoadjuvant Cy/GVAX induced high levels of PD-L1 expression and the formation of novel vaccine-induced, immunologically active, tertiary lymphoid aggregates. Methods: In this multi-center, open label, phase II clinical trial, patients with BR-PDAC will receive a total of four 28-day cycles of FOLFIRINOX. Subsequently they will undergo EUS-guided fiducial placement along with SBRT simulation and core biopsy. Within 2-6 weeks after chemotherapy, patients will receive their first dose of combination immunotherapy, consisting of Cy 200 mg/m2 IV and nivolumab 240mg IV on day 1 followed by 5 x 108 GVAX vaccine cells, administered as six intradermal injections, on day 2. Approximately three weeks later, patients will receive their second dose of combined immunotherapy on the same day as initiation of SBRT (6.6 Gy x 5 days). Following completion of immunotherapy and SBRT, patients will undergo repeat imaging, surgical re-evaluation and if resectable, proceed to definitive surgical resection. This study will recruit 50 patients to achieve 45 evaluable patients receiving immunotherapy. The primary endpoint is pCR rate. Secondary endpoints include: rate of R0 resections, ORR, OS, distant metastasis free survival, adverse events (graded by NCI CTCAE). Additionally, exploratory objectives include evaluating: 1. intratumoral immune infiltrates in pre- and post-treatment biopsy specimens utilizing immunohistochemistry and transcriptional analysis, 2. circulating biomarkers including plasma tumor DNA and circulating tumor cells. Key inclusion criteria for this study include: having BR- PDAC, no more than 1 month or 1 cycle (28 days) of systemic therapy for PDAC, and ECOG performance status of ≤ 1. This clinical trial is open, actively recruiting and is supported by BMS and the Skip Viragh Foundation. Clinical trial information: NCT03161379. Citation Format: Arsen Osipov, Elizabeth Sugar, Anna Ferguson, Jennifer Durham, Christina Rodriguez, Rose Parkinson, Laura Sena, Lei Zheng, Christopher Wolfgang, Richard Burkhart, Jin He, Matthew Weiss, Amol Narang, Daniel Laheru, Nilofer Azad, Elizabeth Jaffee, Colin Weekes, Mark Yarchoan. A Phase II clinical trial of GVAX pancreas vaccine (with Cyclophosphamide) in combination with Nivolumab and Stereotactic Body Radiation Therapy (SBRT) followed by definitive resection for patients with borderline resectable pancreatic adenocarcinoma (BR-PDAC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT164.

Epigenetic alternate promoter utilization and association with PD-L1 expression in Epstein–Barr virus positive gastric cancer.

e15509 Background: We recently elicited the role of epigenetic promoter alterations as a mechanism of immune-evasion and primary resistance to immune checkpoint inhibition in gastric cancer. High prevalence of epigenetic modifications are known to occur in Epstein-Barr virus associated gastric cancer (EBVaGC). EBVaGC has high response rates to anti-PD-1 immune checkpoint inhibitors and is associated with high levels of PD-L1 expression. However, not all EBVaGC express PD-L1 and mechanisms that mediate these phenomena are unknown. Methods: We performed NanoString profiling and PD-L1 immunohistochemistry (using Dako PD-L1 IHC 22C3) on tissue from gastric cancer patients undergoing primary tumor resections at Samsung Medical Centre, South Korea. NanoString panel was designed for 90 recurrent somatic alternate promoter-related genes, and immune-related genes including PD-L1. EBV status was determined using EBV-encoded RNA in situ hybridization and categorized as EBVaGC and EBV-negative. Samples in the top-quartile of alternate promoter utilization were classified as APhigh and the remaining APlow. Results: A total of 272 samples (EBVaGC n = 79; EBV-negative n = 193) were included in this study. EBVaGC had significantly higher PD-L1 expression (p &lt; 0.001) compared to EBV-negative samples. APhigh group (n = 67) consisted of 61 EBV-negative and 6 EBVaGC samples. EBVaGC APhigh tumors had significantly lower PD-L1 transcript expression compared to EBVaGC APlow tumors (p = 0.011, Wilcoxon-rank sum). Similar correlation was also found with PD-L1 IHC combined positive score (CPS)(median CPS score 1 vs 8, p = 0.047). There was a trend towards poorer survival for EBVaGC APhigh tumors (vs EBVaGC APlow; HR 0.23, 95% CI: 0.046 – 1.23, p = 0.087). EBV-negative APhigh tumors also had lower PD-L1 expression (vs EBV-negative APlow; p = 0.046, Wilcoxon-rank sum). Conclusions: Increased utilization of epigenetic alternate promoter isoforms correlates with lower transcriptomic and protein expression of PD-L1 in EBVaGC. Here we describe a potential mechanism of immune-evasion to explain low immune-infiltration and PD-L1 expression that occurs in a group of EBVaGC that is traditionally considered highly immunogenic.

Randomized open-label study of M7824 versus pembrolizumab as first-line (1L) treatment in patients with PD-L1 expressing advanced non-small cell lung cancer (NSCLC).

TPS9114 Background: Transforming growth factor β (TGF- β) promotes tumor progression via immune- and non–immune-related processes. M7824 is an innovative first-in-class bifunctional fusion protein composed of 2 extracellular domains of TGF-βRII (a TGF-β “trap”) fused to a human IgG1 monoclonal antibody against PD-L1. Targeting these independent and complementary pathways may restore and enhance antitumor responses. An expansion cohort of the NCT02517398 study of patients with advanced NSCLC (n = 80) treated with M7824 in the second-line setting presented at ESMO 2018 showed an objective response rate of 86% in the subgroup with high PD-L1 tumor expression at the recommended phase 2 dose (1200 mg intravenously [IV] every 2 weeks [Q2W]). Observed data support the hypothesis that M7824 may be superior to other PD-(L)1 inhibitors, including pembrolizumab, for the treatment of NSCLC. Based on the promising antitumor activity and manageable safety profile, this study will evaluate M7824 treatment in patients with advanced NSCLC in the 1L setting. Methods: Here we present a global, randomized trial comparing M7824 vs pembrolizumab in the 1L treatment of patients with metastatic NSCLC with high PD-L1 expression levels. Patients in this study must have a histologically confirmed diagnosis of advanced NSCLC with high PD-L1 expression on tumor cells (defined as either ≥80% by the Dako 73-10 pharmDx kit or ≥50% by the Dako 22C3 pharmDx kit since both assays are expected to select a similar patient population at their respective cut-offs). ECOG performance status must be 0 or 1. Patients must not have received prior systemic treatment for advanced NSCLC. Patients with tumors with actionable mutations (for which targeted therapy is locally approved) are not eligible. Patients will receive 1200 mg Q2W or pembrolizumab 200 mg Q3W as an IV infusion until confirmed disease progression, unacceptable toxicity, or trial withdrawal. Dual primary endpoints are progression-free survival and best overall response; key secondary endpoints include overall survival, duration of response, and safety. Estimated enrollment is 300 patients. Clinical trial information: NCT03631706.

B cells produce IL-27 to upregulate PD-L1 expression and promote breast cancer development

Abstract The host immune response can be corrupted by cancer cells during tumor progression. Here we showed that B lymphocytes played an important role in promoting murine breast cancer (BCa) development, as B cell-deficient mMT mice displayed virtually abrogated tumor growth from transplanted syngeneic ERa+ breast adenocarcinoma cells, concomitant with reduced PD-L1 expression and increased BCa cell death. In murine BCa tumors and tumor-associated lymph nodes, B cells were the major source of IL-27, a pleotropic cytokine with both pro- and anti-inflammatory functions. Deficiency in IL-27 expression specifically in B cells abolished the BCa tumor growth, showing that the effect of B cells in BCa development was mainly through IL-27 production, as likely induced by TLR ligands in the tumor microenvironment together with CD154 and IL-21 expressed by tumor-infiltrating CD4+ T cells. IL-27 treatment of BCa cells resulted in STAT1 and STAT3 phosphorylation, upregulated PD-L1 gene expression and enhanced cell growth. In addition, IL-27 induced activated B cells to express PD-L1 in vitro, consistent with high levels of PD-L1 expression by B cells in tumors. In humans, IL-27 receptor genes were highly expressed in the breast tissue, at levels comparable to those in lymphoid organs, and high IL-27 gene expression was associated with reduced survival in BCa patients, who displayed increased circulating IL-27 levels. Finally, IL-27 supported human BCa cell growth in the presence of tamoxifen, suggesting a role of IL-27 in the drug resistance. Thus, TLR-fueled IL-27 induction in B cells reinforces PD-L1 expression in the tumor environment to drive BCa cell growth and to promote generation of PD-L1hi B regulatory cells, leading to BCa tumor progression.

Advanced Non-Small Cell Lung Cancer: Sequencing Agents in the EGFR-Mutated/ALK-Rearranged Populations.

Personalized therapy based on actionable molecular markers has completely transformed the therapeutic landscape in advanced non-small cell lung cancer (NSCLC). In less than 15 years, multiple molecular targets, led by EGFR and anaplastic lymphoma kinase (ALK), have been identified, and myriad oral tyrosine kinase inhibitors (TKIs) are now available to target these oncogenic drivers, with the expectation that the majority of patients will respond to treatment and that progression-free survival (PFS) will exceed 10 to 30 months, far better than we observed historically with chemotherapy alone. As a result, prognosis has improved dramatically in this subset of patients. Osimertinib has largely displaced first- and second-generation EGFR TKIs, including gefitinib, erlotinib, and afatinib, in the management of EGFR-mutated NSCLC. PFS now exceeds 18 months, and central nervous system penetrance is enhanced. Dacomitinib has the distinction of being the first EGFR TKI to demonstrate a survival advantage compared with older TKIs. Recent data suggest therapeutic additivity, if not synergy, for the concurrent use of chemotherapy, as well as monoclonal antibodies targeting angiogenesis, with EGFR TKIs. Alectinib and brigatinib, very specific ALK inhibitors, have proven superior to the erstwhile standard crizotinib in treatment-naive ALK+ NSCLC; PFS now routinely exceeds 2 to 3 years. In addition, these newer agents have far superior central nervous system penetration. As a result, many patients with ALK+ advanced NSCLC with brain metastases, even some who are symptomatic, can defer or indefinitely avoid brain irradiation. Mechanisms of resistance in ALK are complicated, with multiple new agents being developed in this arena. Although many patients with molecular targets can reasonably expect to live 5 years or more, the emergence of molecular resistance is virtually inevitable. In this regard, systemic platinum-based chemotherapy is the final common therapeutic pathway for virtually all patients with oncogenic drivers. Standard regimens include pemetrexed and carboplatin, as well as the E4599 regimen, combination solvent-based paclitaxel, carboplatin, and bevacizumab. Checkpoint inhibitors, as single agents, have not yielded much benefit, even in those with high levels of PD-L1 expression. However, in a subanalysis of patients with ALK and EGFR mutations enrolled in IMpower150, the addition of atezolizumab to the E4599 regimen led to a major overall survival benefit (hazard ratio < 0.40). In the absence of systemic chemotherapy, combining checkpoint inhibitors with TKIs in this setting remains investigational; several studies have demonstrated untoward pulmonary and hepatic toxicity.

Successful treatment of recurrent unresectable squamous cell carcinoma of the head and neck using pembrolizumab

The study objective is to report a case of successful treatment of recurrent unresectable squamous cell carcinoma of the head and neck using pembrolizumab (selective inhibitor, preventing the interaction between the programmed death receptor 1 (PD1) and its ligands PD-L1 and PD-L2). Materials and metho ds. A 72-year-old male patient was admitted to the Clinic of Head and Neck Tumors, N.N. Blokhin Russian Cancer Research Center with the following diagnosis: primary metachronous malignant tumors: 1) oropharyngeal cancer T2N3M0 (after chemoradiotherapy, no relapse or metastases), 2) skin cancer of the left ear (T2N0M0, stage II, after combination treatment); relapse. After multiple surgeries for repeated relapses and external beam radiotherapy in March 2017, the patient was found to have new metastatic lesions in the retropharyngeal lymph nodes and paravertebral soft tissues of the neck (left side). The tumor was considered unresectable. The patient had high level of PD-L1 expression in the tumor (50 %), therefore, it was decided to initiate treatment with PD-1 inhibitors. The patient received pembrolizumab (keytruda) 200 mg once every three weeks (7 courses). Results . Positron emission tomography performed in February 2018 demonstrated no increased uptake of radiopharmaceutical in the retropharyngeal lymph nodes and paravertebral soft tissues of the neck, which were earlier affected. Since that time, the patient demonstrates sustained remission without any therapy. Conclusion . This case not only shows high efficacy of PD-1 inhibitors for aggressive recurrent head and neck squamous cell carcinoma, but also opens new opportunities for the treatment of weakened patients after chemotherapy and radiation exposure.

Randomized open-label study of M7824 versus pembrolizumab as first-line (1L) treatment in patients with PD-L1 expressing advanced non-small cell lung cancer (NSCLC).

TPS127 Background: Transforming growth factor β (TGF- β) promotes tumor progression via immune- and non–immune-related processes. M7824 is an innovative first-in-class bifunctional fusion protein composed of 2 extracellular domains of TGF-βRII (a TGF-β “trap”) fused to a human IgG1 monoclonal antibody against PD-L1. Targeting these independent and complementary pathways may restore and enhance antitumor responses. An expansion cohort of the study of patients with advanced NSCLC (n=80) treated with M7824 in the second-line setting presented at ESMO 2018 showed an objective response rate of 86% in the subgroup with high PD-L1 tumor expression at the recommended phase 2 dose (1200 mg intravenously [IV] every 2 weeks [Q2W]). Observed data support the hypothesis that M7824 may be superior to other PD-(L)1 inhibitors, including pembrolizumab, for the treatment of NSCLC. Based on the promising antitumor activity and manageable safety profile, this study will evaluate M7824 treatment in patients with advanced NSCLC in the 1L setting. Methods: Here we present a global, randomized trial comparing M7824 vs pembrolizumab in the 1L treatment of patients with metastatic NSCLC with high PD-L1 expression levels. Patients in this study must have a histologically confirmed diagnosis of advanced NSCLC with high PD-L1 expression on tumor cells (defined as either ≥80% by the Dako 73-10 pharmDx kit or ≥50% by the Dako 22C3 pharmDx kit since both assays are expected to select a similar patient population at their respective cut-offs). ECOG performance status must be 0 or 1. Patients must not have received prior systemic treatment for advanced NSCLC. Patients with tumors with actionable mutations (for which targeted therapy is locally approved) are not eligible. Patients will receive 1200 mg Q2W or pembrolizumab 200 mg Q3W as an IV infusion until confirmed disease progression, unacceptable toxicity, or trial withdrawal. Dual primary endpoints are progression-free survival and best overall response; key secondary endpoints include overall survival, duration of response, and safety. Estimated enrollment is 300 patients. Clinical trial information: NCT02517398, NCT03631706 .