B-cell infiltration is associated with survival outcomes following programmed cell death protein 1 inhibition in head and neck squamous cell carcinoma

BACKGROUND

Programmed cell death protein 1 (PD-1) axis blockade has become the mainstay in the treatment of recurrent and/or metastatic (R/M) head and neck squamous cell cancer (HNSCC). Programmed death-ligand 1 (PD-L1) is the only approved biomarker for patient selection; however, response rate is limited even among high expressors. Our primary objective was to investigate the association of immune cell-related biomarkers in the tumor and tumor microenvironment with PD-1 checkpoint inhibitors' outcomes in patients with R/M HNSCC.

PATIENTS AND METHODS

NCT03652142 was a prospective study in nivolumab-treated platinum-refractory R/M HNSCC, aiming to evaluate biomarkers of response to treatment. Tumor biopsies and blood samples were collected from 60 patients at baseline, post-treatment, and at progression. Immune cells in the tumor and stromal compartments were quantified by immunofluorescence using a five-protein panel (CD3, CD8, CD20, FoxP3, cytokeratin). Tertiary lymphoid structures (TLSs), PD-L1 expression, and peripheral blood immune cell composition were also evaluated for associations with outcome. Our findings were validated by gene set enrichment analysis (GSEA) messenger RNA in situ expression data from the same patients, for B-cell- and TLS-associated genes.

RESULTS

High pre-treatment density of stromal B cells was associated with prolonged progression-free survival (PFS) (P = 0.011). This result was validated by GSEA, as stromal enrichment with B-cell-associated genes showed association with response to nivolumab. PD-L1 positivity combined with high B-cell counts in stroma defined a subgroup with significantly longer PFS and overall survival (P = 0.013 and P = 0.0028, respectively).

CONCLUSIONS

Increased B cells in pre-treatment HNSCC biopsy samples correlate with prolonged benefit from PD-1-based immunotherapy and could further enhance the predictive value of PD-L1 expression.

Well-differentiated liposarcomas and dedifferentiated liposarcomas: Systemic treatment options for two sibling neoplasms

Well-differentiated liposarcomas (WDLPS) and dedifferentiated liposarcomas (DDLPS) account for 60 % of all liposarcomas, reflecting the heterogeneity of this type of sarcoma. Genetically, both types of liposarcomas are characterized by the amplification of MDM2 and CDK4 genes, which indicates an important molecular event with diagnostic and therapeutic relevance. In both localized WDLPS and DDLPS of the retroperitoneum and the extremities, between 25 % and 30 % of patients have local or distant recurrence, even when perioperatively treated, with clear margins present. The systemic treatment of WDLPS and DDLPS remains a challenge, with anthracyclines as the gold standard for first-line treatment. Several regimens have been tested with modest results regarding their efficacy. Herein we discuss the systemic treatment options for WDLPS and DDLPS and review their reported clinical efficacy results.

Immune checkpoint inhibitors in sarcomas: a systematic review

Sarcomas are tumors that originate from mesenchymal cells. The variety of sarcomas' response to chemotherapy and the wide range of prognosis reflect their heterogeneity. In order to improve the rates of response, the research has been orientated toward other forms of therapy, such as targeted therapies and immunotherapy or toward combinations of them. Immune checkpoint inhibitors (ICIs) have been the highlight of immunotherapy in the last decade. Although ICIs are already included in the guidelines of different malignancies, their clinical benefit in sarcomas is still under study. Alveolar soft part sarcomas, undifferentiated pleomorphic sarcomas and other subtypes of sarcoma with high presence of tertiary lymphoid structures tend to respond to ICIs, but further investigation is still needed. Furthermore, the search of predictive biomarkers to determine the type of sarcomas that are sensitive to ICIs is still very challenging. This review will focus on the results of clinical trials, which examine the effect of ICIs and their combination with chemotherapy, targeted therapies and other forms of immunotherapy in sarcomas.

Emerging Prognostic and Predictive Significance of Stress Keratin 17 in HPV-Associated and Non HPV-Associated Human Cancers: A Scoping Review

A growing body of literature suggests that the expression of cytokeratin 17 (K17) correlates with inferior clinical outcomes across various cancer types. In this scoping review, we aimed to review and map the available clinical evidence of the prognostic and predictive value of K17 in human cancers. PubMed, Web of Science, Embase (via Scopus), Cochrane Central Register of Controlled Trials, and Google Scholar were searched for studies of K17 expression in human cancers. Eligible studies were peer-reviewed, published in English, presented original data, and directly evaluated the association between K17 and clinical outcomes in human cancers. Of the 1705 studies identified in our search, 58 studies met criteria for inclusion. Studies assessed the prognostic significance (n = 54), predictive significance (n = 2), or both the prognostic and predictive significance (n = 2). Altogether, 11 studies (19.0%) investigated the clinical relevance of K17 in cancers with a known etiologic association to HPV; of those, 8 (13.8%) were focused on head and neck squamous cell carcinoma (HNSCC), and 3 (5.1%) were focused on cervical squamous cell carcinoma (SCC). To date, HNSCC, as well as triple-negative breast cancer (TNBC) and pancreatic cancer, were the most frequently studied cancer types. K17 had prognostic significance in 16/17 investigated cancer types and 43/56 studies. Our analysis suggests that K17 is a negative prognostic factor in the majority of studied cancer types, including HPV-associated types such as HNSCC and cervical cancer (13/17), and a positive prognostic factor in 2/17 studied cancer types (urothelial carcinoma of the upper urinary tract and breast cancer). In three out of four predictive studies, K17 was a negative predictive factor for chemotherapy and immune checkpoint blockade therapy response.

Stress Keratin 17 Is a Predictive Biomarker Inversely Associated with Response to Immune Check-Point Blockade in Head and Neck Squamous Cell Carcinomas and Beyond

Low response rates in immune check-point blockade (ICB)-treated head and neck squamous cell carcinoma (HNSCC) drive a critical need for robust, clinically validated predictive biomarkers. Our group previously showed that stress keratin 17 (CK17) suppresses macrophage-mediated CXCL9/CXCL10 chemokine signaling involved in attracting activated CD8+ T cells into tumors, correlating with decreased response rate to pembrolizumab-based therapy in a pilot cohort of ICB-treated HNSCC (n = 26). Here, we performed an expanded analysis of the predictive value of CK17 in ICB-treated HNSCC according to the REMARK criteria and investigated the gene expression profiles associated with high CK17 expression. Pretreatment samples from pembrolizumab-treated HNSCC patients were stained via immunohistochemistry using a CK17 monoclonal antibody (n = 48) and subjected to spatial transcriptomic profiling (n = 8). Our findings were validated in an independent retrospective cohort (n = 22). CK17 RNA expression in pembrolizumab-treated patients with various cancer types was investigated for predictive significance. Of the 48 patients (60% male, median age of 61.5 years), 21 (44%) were CK17 high, and 27 (56%) were CK17 low. A total of 17 patients (35%, 77% CK17 low) had disease control, while 31 patients (65%, 45% CK17 low) had progressive disease. High CK17 expression was associated with a lack of disease control (p = 0.037), shorter time to treatment failure (p = 0.025), and progression-free survival (PFS, p = 0.004), but not overall survival (OS, p = 0.06). A high CK17 expression was associated with lack of disease control in an independent validation cohort (p = 0.011). PD-L1 expression did not correlate with CK17 expression or clinical outcome. CK17 RNA expression was predictive of PFS and OS in 552 pembrolizumab-treated cancer patients. Our findings indicate that high CK17 expression may predict resistance to ICB in HNSCC patients and beyond.

Phase II Window Study of Olaparib Alone or with Cisplatin or Durvalumab in Operable Head and Neck Cancer

Purpose

We conducted a phase II randomized noncomparative window of opportunity (WOO) trial to evaluate the inhibition of cellular proliferation and the modulation of immune microenvironment after treatment with olaparib alone or in combination with cisplatin or durvalumab in patients with operable head and neck squamous cell carcinoma (HNSCC).

Experimental Design

Forty-one patients with HNSCC were randomized to cisplatin plus olaparib (arm A), olaparib alone (arm B), no treatment (arm C) or durvalumab plus olaparib (arm D). The primary endpoint was to evaluate the percentage of patients in each arm that achieved a reduction of at least 25% in Ki67. Secondary endpoints included objective response rate (ORR), safety, and pathologic complete response (pCR) rate. Paired baseline and resection tumor biopsies and blood samples were evaluated for prespecified biomarkers.

Results

A decrease in Ki67 of at least 25% was observed in 44.8% of treated patients, as measured by quantitative immunofluorescence. The ORR among treated patients was 12.1%. pCR was observed in 2 patients. Two serious adverse events occurred in 2 patients.Programmed death ligand 1 (PD-L1) levels [combined positive score (CPS)] were significantly higher after treatment in arms A and D. Expression of CD163 and colony-stimulating factor 1 receptor (CSF1R) genes, markers of M2 macrophages, increased significantly posttreatment whereas the expression of CD80, a marker of M1 macrophages, decreased.

Conclusion

Preoperative olaparib with cisplatin or alone or with durvalumab was safe in the preoperative setting and led to decrease in Ki67 of at least 25% in 44.8% of treated patients. Olaparib-based treatment modulates the tumor microenvironment leading to upregulation of PD-L1 and induction of protumor features of macrophages.

Significance

HNSCC is characterized by defective DNA repair pathways and immunosuppressive tumor microenvironment. PARP inhibitors, which promote DNA damage and "reset" the inflammatory tumor microenvironment, can establish an effective antitumor response. This phase II WOO trial in HNSCC demonstrated the immunomodulatory effects of PARP inhibitor-induced DNA damage. In this chemo-naïve population, PARP inhibitor-based treatment, reduced tumor cell proliferation and modulated tumor microenvironment. After olaparib upregulation of PD-L1 and macrophages, suggests that combinatorial treatment might be beneficial.

Synopsis

Our WOO study demonstrates that preoperative olaparib results in a reduction in Ki67, upregulation of PD-L1 CPS, and induction of protumor features of macrophages in HNSCC.

Digital Spatial Profiling Links Beta-2-microglobulin Expression with Immune Checkpoint Blockade Outcomes in Head and Neck Squamous Cell Carcinoma

Programmed cell death protein-1 (PD-1)-targeted immunotherapy is approved for recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) treatment. Although its efficacy correlates with PD-L1 expression, response is limited even among positive cases. We employed digital spatial profiling (DSP) to discover potential biomarkers of immunotherapy outcomes in HNSCC. Fifty prospectively collected, pretreatment biopsy samples from patients with anti-PD-1-treated R/M HNSCC, were assessed using DSP, for 71 proteins in four molecularly defined compartments (tumor, leukocyte, macrophage, and stroma). Markers were evaluated for associations with progression-free (PFS) and overall survival (OS). High beta-2 microglobulin (B2M), LAG-3, CD25, and 4-1BB in tumor; high B2M, CD45, CD4 in stroma, and low fibronectin in the macrophage compartment, correlated with prolonged PFS. Improved PFS and OS were observed for cases with high B2M by quantitative and mRNA. Findings were validated in an independent cohort for PFS (HR, 0.41; 95% confidence interval, 0.19-0.93; P = 0.034). B2M-high tumors showed enrichment with immune cell and immune checkpoint markers. Our study illustrates B2M expression is associated with improved survival for immune checkpoint inhibitor (ICI)-treated HNSCC.

Significance

In the current study, DSP revealed the positive association of B2M expression in the tumor compartment with immunotherapy outcomes in R/M HNSCC.

Spatial characterization and quantification of CD40 expression across cancer types

BACKGROUND

CD40, a TNF receptor family member, is expressed by a variety of immune cells and is involved in the activation of both adaptive and innate immune responses. Here, we used quantitative immunofluorescence (QIF) to evaluate CD40 expression on the tumor epithelium of solid tumors in large patient cohorts of lung, ovarian, and pancreatic cancers.

METHODS

Tissue samples from nine different solid tumors (bladder, breast, colon, gastric, head and neck, non-small cell lung cancer (NSCLC), ovarian, pancreatic and renal cell carcinoma), constructed in tissue microarray format, were initially assessed for CD40 expression by QIF. CD40 expression was then evaluated on the large available patient cohorts for three of the tumor types demonstrating high CD40 positivity rate; NSCLC, ovarian and pancreatic cancer. The prognostic impact of CD40 expression on tumor cells was also investigated.

RESULTS

CD40 expression on tumor cells was found to be common, with 80% of the NSCLC population, 40% of the ovarian cancer population, and 68% of the pancreatic adenocarcinoma population displaying some degree of CD40 expression on cancer cells. All of three of these cancer types displayed considerable intra-tumoral heterogeneity of CD40 expression, as well as partial correlation between expression of CD40 on tumor cells and on surrounding stromal cells. CD40 was not found to be prognostic for overall survival in NSCLC, ovarian cancer, or pancreatic adenocarcinoma.

CONCLUSIONS

The high percentage of tumor cells expressing CD40 in each of these solid tumors should be considered in the development of therapeutic agents designed to target CD40.

Next-generation sequencing (NGS) profiling of matched tumor and circulating tumor DNA (ctDNA) in head and neck squamous cell carcinoma (HNSCC)

OBJECTIVES

The aim of this pilot study was to evaluate the presence of somatic mutations in matched tumor and circulating DNA (ctDNA) samples from patients with primary head and neck squamous cell carcinoma (HNSCC) and assess the association of changes in ctDNA levels with survival.

MATERIALS AND METHODS

Our study included 62 patients with stage I-IVB HNSCC treated with surgery or radical chemoradiotherapy with curative intent. Plasma samples were obtained at baseline, at the end of treatment (EOT), and at disease progression. Tumor DNA was extracted from plasma (ctDNA) and tumor tissue (tDNA). The Safe Sequencing System was used assess the presence of pathogenic variants in four genes (TP53, CDKN2A, HRAS and PI3KCA) in both ctDNA and tDNA.

RESULTS

Forty-five patients had available tissue and plasma samples. Concordance of genotyping results between tDNA and ctDNA at baseline was 53.3%. TP53 mutations were most commonly identified at baseline in both ctDNA (32.6%) and tDNA (40%). The presence of mutations in this restricted set of 4 genes in tissue samples at baseline was associated with decreased overall survival (OS) [median 58.3 months for patients with mutations vs. 89 months for patients without mutations, p < 0.013]. Similarly, patients presenting with mutations in ctDNA had shorter OS [median 53.8 vs. 78.6 months, p < 0.037]. CtDNA clearance at EOT did not show any association with PFS or OS.

CONCLUSIONS

Liquid biopsy enables real-time molecular characterization of HNSCC and might predict survival. Larger studies are needed to validate the utility of ctDNA as a biomarker in HNSCC.

Quantitative, Spatially Defined Expression of Leukocyte-associated Immunoglobulin-like Receptor in Non-small Cell Lung Cancer

Targeting the interaction of leukocyte-associated immunoglobulin-like receptor-1 (LAIR-1) and its ligands has been shown to reinstate antitumor immunity. In addition, the introduction of the LAIR-1 decoy protein, LAIR-2, sensitizes previously resistant lung tumors to programmed death-1 (PD-1) blockade, indicating the potential of LAIR-1 as an alternative marker for anti-PD-1 resistance in lung cancer. Here, we assessed LAIR-1 as compared with programmed death-ligand 1 (PD-L1) expression in various tumors, with a focus on non-small cell lung cancer (NSCLC) and its histologic subtypes using multiplexed quantitative immunofluorescence (mQIF) in 287 (discovery cohort) and 144 (validation cohort) patients with NSCLC. In addition, using multispectral imaging technology on mQIF images, we evaluated the localization of LAIR-1 on various cell types. We observed that CD14+, CD68+, and CD163+ monocytes and CK+ tumor cells predominantly expressed LAIR-1 more than other cell types. Furthermore, LAIR-1 expression in the tumor compartment was significantly higher in patients with lung adenocarcinoma (LUAD) than those with lung squamous cell carcinoma subtype (**, P = 0.003). Our results indicated that high tumor LAIR-1 expression in patients with LUAD is negatively associated with OS (overall survival, HR = 2.4; *, P = 0.02) highlighting its prognostic value in LUAD but not in other subtypes. The Pearson correlation between LAIR-1 and PD-L1 is 0.31; however, mutual exclusive staining pattern (i.e., several cases were positive for LAIR-1 and negative for PD-L1) was observed. Altogether, our data suggest that the combination therapy of anti-PD-1/PD-L1 with anti-LAIR-1 or the anti-LAIR-1 monotherapy alone may be promising cancer immunotherapeutic strategies.

Significance

The spatial, quantitative assessment of LAIR-1 in NSCLC shows positive association of OS with high LAIR-1+/CD68+ cell densities and negative association of OS with high LAIR-1 expression in LUAD tumor subtype.

Baseline gene expression profiling determines long-term benefit to programmed cell death protein 1 axis blockade

Treatment with immune checkpoint inhibitors has altered the course of malignant melanoma, with approximately half of the patients with advanced disease surviving for more than 5 years after diagnosis. Currently, there are no biomarker methods for predicting outcome from immunotherapy. Here, we obtained transcriptomic information from a total of 105 baseline tumor samples comprising two cohorts of patients with advanced melanoma treated with programmed cell death protein 1 (PD-1)-based immunotherapies. Gene expression profiles were correlated with progression-free survival (PFS) within consecutive clinical benefit intervals (i.e., 6, 12, 18, and 24 months). Elastic net binomial regression models with cross validation were utilized to compare the predictive value of distinct genes across time. Lasso regression was used to generate a signature predicting long-term benefit (LTB), defined as patients who remain alive and free of disease progression at 24 months post treatment initiation. We show that baseline gene expression profiles were consistently able to predict long-term immunotherapy outcomes with high accuracy. The predictive value of different genes fluctuated across consecutive clinical benefit intervals, with a distinct set of genes defining benefit at 24 months compared to earlier outcomes. A 12-gene signature was able to predict LTB following anti-PD-1 therapy with an area under the curve (AUC) equal to 0.92 and 0.74 in the training and validation set, respectively. Evaluation of LTB, via a unique signature may complement objective response classification and characterize the logistics of sustained antitumor immune responses.

Programmed Cell Death Protein 1 Axis Inhibition in Viral Infections: Clinical Data and Therapeutic Opportunities

A vital function of the immune system is the modulation of an evolving immune response. It is responsible for guarding against a wide variety of pathogens as well as the establishment of memory responses to some future hostile encounters. Simultaneously, it maintains self-tolerance and minimizes collateral tissue damage at sites of inflammation. In recent years, the regulation of T-cell responses to foreign or self-protein antigens and maintenance of balance between T-cell subsets have been linked to a distinct class of cell surface and extracellular components, the immune checkpoint molecules. The fact that both cancer and viral infections exploit similar, if not the same, immune checkpoint molecules to escape the host immune response highlights the need to study the impact of immune checkpoint blockade on viral infections. More importantly, the process through which immune checkpoint blockade completely changed the way we approach cancer could be the key to decipher the potential role of immunotherapy in the therapeutic algorithm of viral infections. This review focuses on the effect of programmed cell death protein 1/programmed death-ligand 1 blockade on the outcome of viral infections in cancer patients as well as the potential benefit from the incorporation of immune checkpoint inhibitors (ICIs) in treatment of viral infections.

Quantitative assessment of Siglec-15 expression in lung, breast, head, and neck squamous cell carcinoma and bladder cancer

Immune checkpoint blockade with programmed cell death (PD-1)/programmed death-ligand 1 (PD-L1) inhibitors has resulted in significant progress in the treatment of various cancer types. However, not all patients respond to PD-1/PD-L1 blockade, underscoring the importance of identifying new potential targets for immunotherapy. One promising target is the immune system modulator Siglec-15. In this study, we assess Siglec-15 expression in solid tumors, with a focus on lung, breast, head and neck squamous and bladder cancers. Using quantitative immunofluorescence (QIF) with a previously validated antibody, we found increased Siglec-15 expression in both tumor and immune cells in all the four cancer types. Siglec-15 was seen to be predominantly expressed by the stromal immune cells (83% in lung, 70.1% in breast, 95.2% in head and neck squamous cell and 89% in bladder cancers). Considerable intra-tumoral heterogeneity was noted across cancer types. As previously described for non-small cell lung cancer (NSCLC), Siglec-15 expression was seen to be mutually exclusive to PD-L1 in all the four cancer types, although this differential expression was maintained but somewhat diminished in head and neck squamous cell carcinoma (HNSCC). Siglec-15 was not prognostic either for overall survival (OS) or progression-free survival (PFS). In summary, we show broad expression of this potential immune modulatory target in a wide range of cancer types. These data suggest potential future clinical trials in these tumor types.

Spatially resolved proteomic profiling identifies tumor cell CD44 as a biomarker associated with sensitivity to PD-1 axis blockade in advanced non-small-cell lung cancer

BACKGROUND

Most patients with advanced non-small-cell lung cancer (NSCLC) fail to derive significant benefit from programmed cell death protein-1 (PD-1) axis blockade, and new biomarkers of response are needed. In this study, we aimed to discover and validate spatially resolved protein markers associated with sensitivity to PD-1 axis inhibition in NSCLC.

METHODS

We initially assessed a discovery cohort of 56 patients with NSCLC treated with PD-1 axis inhibitors at Yale Cancer Center. Using the GeoMx Digital Spatial Profiling (DSP) system, 71 proteins were measured in spatial context on each spot in a tissue microarray. We used the AQUA method of quantitative immunofluorescence (QIF) to orthogonally validate candidate biomarkers. For external independent validation, we assessed whole tissue sections derived from 128 patients with NSCLC treated with single-agent PD-1 axis inhibitors at the 12 de Octubre Hospital (Madrid) using DSP. We further analyzed two immunotherapy untreated cohorts to address prognostic significance (n=252 from Yale Cancer Center; n=124 from University Clinic of Navarra) using QIF and DSP, respectively.

RESULTS

Using continuous log-scaled data, we identified CD44 expression in the tumor compartment (pan-cytokeratin (CK)+) as a novel predictor of prolonged progression-free survival (PFS) (multivariate HR=0.68, p=0.043) in the discovery set. We validated by QIF that tumor CD44 levels assessed as continuous QIF scores were associated with longer PFS (multivariate HR=0.31, p=0.022) and overall survival (multivariate HR=0.29, p=0.038). Using DSP in an independent immunotherapy treated cohort, we validated that CD44 levels in the tumor compartment, but not in the immune compartment (panCK-/CD45+), were associated with clinical benefit (OR=1.22, p=0.018) and extended PFS under PD-1 axis inhibition using the highest tertile cutpoint (multivariate HR=0.62, p=0.03). The effect of tumor cell CD44 in predicting PFS remained significant after correcting for programmed death-ligand 1 (PD-L1) Tumor Proportion Score (TPS) in both cohorts. High tumor cell CD44 was not prognostic in the absence of immunotherapy. Using DSP data, intratumoral regions with elevated tumor cell CD44 expression showed prominent (fold change>1.5, adjusted p<0.05) upregulation of PD-L1, TIM-3, ICOS, and CD40 in two independent cohorts.

CONCLUSIONS

This work highlights CD44 as a novel indicative biomarker of sensitivity to PD-1 axis blockade that might help to improve immunotherapy strategies for NSCLC.

Discovery of Biomarkers of Resistance to Immune Checkpoint Blockade in NSCLC Using High-Plex Digital Spatial Profiling

INTRODUCTION

Despite the clinical efficacy of immune checkpoint inhibitors (ICIs) in NSCLC, only approximately 20% of patients remain disease-free at 5 years. Here, we use digital spatial profiling to find candidate biomarker proteins associated with ICI resistance.

METHODS

Pretreatment samples from 56 patients with NSCLC treated with ICI were analyzed using the NanoString GeoMx digital spatial profiling method. A panel of 71 photocleavable oligonucleotide-labeled primary antibodies was used for protein detection in four molecular compartments (tumor, leukocytes, macrophages, and immune stroma). Promising candidates were orthogonally validated with quantitative immunofluorescence. Available pretreatment samples from 39 additional patients with NSCLC who received ICI and 236 non-ICI-treated patients with operable NSCLC were analyzed to provide independent cohort validation.

RESULTS

Biomarker discovery using the protein-based molecular compartmentalization strategy allows 284 protein variables to be assessed for association with ICI resistance by univariate analysis using continuous log-scaled data. Of the 71 candidate protein biomarkers, CD66b in the CD45+CD68 molecular compartment (immune stroma) predicted significantly shorter overall survival (OS) (hazard ratio [HR] 1.31, p = 0.016) and was chosen for validation. Orthogonal validation by quantitative immunofluorescence illustrated that CD66b was associated with resistance to ICI therapy but not prognostic for poor outcomes in untreated NSCLC (discovery cohort [OS HR 2.49, p = 0.026], validation cohort [OS HR 2.05, p = 0.046], non-ICI-treated cohort [OS HR 1.67, p = 0.06]).

CONCLUSIONS

Using the technique, we have discovered that CD66b expression is indicative of resistance to ICI therapy in NSCLC. Given that CD66b identifies neutrophils, further studies are warranted to characterize the role of neutrophils in ICI resistance.

Objective assessment of tumor infiltrating lymphocytes as a prognostic marker in melanoma using machine learning algorithms

BACKGROUND

The prognostic value of tumor-infiltrating lymphocytes (TILs) assessed by machine learning algorithms in melanoma patients has been previously demonstrated but has not been widely adopted in the clinic. We evaluated the prognostic value of objective automated electronic TILs (eTILs) quantification to define a subset of melanoma patients with a low risk of relapse after surgical treatment.

METHODS

We analyzed data for 785 patients from 5 independent cohorts from multiple institutions to validate our previous finding that automated TIL score is prognostic in clinically-localized primary melanoma patients. Using serial tissue sections of the Yale TMA-76 melanoma cohort, both immunofluorescence and Hematoxylin-and-Eosin (H&E) staining were performed to understand the molecular characteristics of each TIL phenotype and their associations with survival outcomes.

FINDINGS

Five previously-described TIL variables were each significantly associated with overall survival (p<0.0001). Assessing the receiver operating characteristic (ROC) curves by comparing the clinical impact of two models suggests that etTILs (electronic total TILs) (AUC: 0.793, specificity: 0.627, sensitivity: 0.938) outperformed eTILs (AUC: 0.77, specificity: 0.51, sensitivity: 0.938). We also found that the specific molecular subtype of cells representing TILs includes predominantly cells that are CD3+ and CD8+ or CD4+ T cells.

INTERPRETATION

eTIL% and etTILs scores are robust prognostic markers in patients with primary melanoma and may identify a subgroup of stage II patients at high risk of recurrence who may benefit from adjuvant therapy. We also show the molecular correlates behind these scores. Our data support the need for prospective testing of this algorithm in a clinical trial.

FUNDING

This work was also supported by a sponsored research agreements from Navigate Biopharma and NextCure and by grants from the NIH including the Yale SPORE in in Skin Cancer, P50 CA121974, the Yale SPORE in Lung Cancer, P50 CA196530, NYU SPORE in Skin Cancer P50CA225450 and the Yale Cancer Center Support Grant, P30CA016359.

Immune Checkpoint Blockade in Hormone Receptor-Positive Breast Cancer: Resistance Mechanisms and Future Perspectives

Anti-programmed cell death protein 1 immunotherapy has been incorporated in the treatment algorithm of triple-negative breast cancer (TNBC). However, clinical trial results for patients with hormone receptor (HR)-positive disease appear less compelling. HR-positive tumors exhibit lower levels of programmed death-ligand 1 expression in comparison with their triple-negative counterparts. Moreover, signaling through estrogen receptor alters the immune microenvironment, rendering such tumors immunologically "cold." To explain differential responses to immune checkpoint blockade, this review interrogates differences between HR-positive and TNBC. Starting from distinct genomic features, we further present disparities concerning the tumor microenvironment and finally, we summarize early-phase clinical trial results on promising novel immunotherapy combinations.

Development of an immunohistochemical assay for Siglec-15

Siglec-15, a member of sialic-acid binding immunoglobulin type lectins, is normally expressed by myeloid cells and upregulated in some human cancers and represents a promising new target for immunotherapy. While PD-L1 blockade is an important strategy for immunotherapy, its effectiveness is limited. The expression of Siglec-15 has been demonstrated to be predominantly mutually exclusive to PD-L1 in certain cancer histologies. Thus, there is significant opportunity for Siglec-15 as an immunotherapeutic target for patients that do not respond to PD-1/PD-L1 inhibition. The aim of this study was to prospectively develop an immunohistochemical (IHC) assay for Siglec-15 to be used as a companion diagnostic for future clinical trials. Here, we create and validate an IHC assay with a novel recombinant antibody to the cytoplasmic domain of Siglec-15. To find an enriched target, this antibody was first used in a quantitative fluorescence (QIF) assay to screen a broad range of tumor histologies to determine tumor types where Siglec-15 demonstrated high expression. Based on this and previous data, we focused on development of a chromogenic IHC assay for lung cancer. Then we developed a scoring system for this assay that has high concordance amongst pathologist readers. We then use this chromogenic IHC assay to test the expression of Siglec-15 in two cohorts of NSCLC. We found that this assay shows a higher level of staining in both tumor and immune cells compared to previous QIF assays utilizing a polyclonal antibody. However, similar to that study, only a small percentage of positive Siglec-15 cases showed high expression for PD-L1. This validated assay for Siglec-15 expression may support development of a companion diagnostic assay to enrich for patients expressing the Siglec-15 target for therapy.

PD-L1 and PD-L2 mRNA measured using closed system qRT-PCR are associated with outcome and high negative predictive value in immunotherapy-treated non-small cell lung cancer

INTRODUCTION

Immune checkpoint inhibitors (ICIs) have become standard of care in lung cancer management, but only a relatively small percentage of patients treated respond. Current predictive biomarkers, including immunohistochemical (IHC) detection of PD-L1, are insufficient for determining who will respond or, more importantly in the adjuvant setting, who will not respond to ICI therapy. Here, we investigate an alternative method of assessment of PD-L1 to predict non-response.

METHODS

This study utilizes a research use only quantitative real-time reverse transcription polymerase chain reaction assay on the GeneXpert® (GX) system, to test for the association between 4 target immune genes, CD274 (PD-L1), PDCD1LG2 (PD-L2), CD8A, and IRF1, and response to ICI therapy. Tissues were collected from 122 patients with advanced non-small cell lung cancer prior to ICI therapy in a retrospective cohort, macro-dissected, and analyzed using the GX.

RESULTS

Both high PD-L1 and PD-L2 mRNA expression levels were associated with improved long-term benefit at 24 months (p=0.047 for both PD-L1 and PD-L2) and overall survival (PD-L1, p= 0.048; PD-L2 p= 0.049). Both PD-L1 and PD-L2 mRNA levels were higher in patients with KRAS mutations. Most importantly, low PD-L1 mRNA showed a high negative predictive value of 0.92 for absence of long-term benefit.

CONCLUSIONS

With further validation this assay in low stage patients, assessment of PD-L1 mRNA rather than protein, could be a method to determine which low stage patients should not be treated with ICIs in the adjuvant setting. This approach may also be a useful objective method for selecting patients for treatment in the advanced setting.

Abstract 2028: Spatially resolved proteomic profiling identifies tumor cell CD44 as a novel indicative biomarker of sensitivity to PD-1 axis blockade in advanced non-small cell lung cancer (NSCLC)

Introduction: Most patients with advanced NSCLC fail to develop durable responses from PD-1 axis blockade, and more robust predictive biomarkers are needed. In this study, we aimed to discover and validate spatially resolved protein markers associated with sensitivity to PD-1 axis inhibition across multiple NSCLC cohorts.

Methods: We first used the GeoMx Digital Spatial Profiling (DSP) system in a discovery cohort of 56 NSCLC patients treated with PD-1 axis inhibitors at Yale (USA). Pre-treatment tumors were represented in a tissue microarray (YTMA471) and analyzed using a 71-plex primary antibody panel. Proteins were measured from three molecularly defined tissue compartments: tumor (CK+), leukocytes (CD45+/CD68-), and macrophages (CD68+). We used quantitative immunofluorescence (QIF) to orthogonally validate candidate biomarkers. For external validation of identified predictors, we assessed pre-treatment whole tissue sections from a cohort of 128 NSCLC patients treated with single-agent PD-1 axis inhibitors at the Hospital 12 de Octubre (Madrid, Spain) using DSP (39-plex protein panel, measured from CK+ and CD45+ compartments). In addition, we analyzed two immunotherapy untreated cohorts to address prognostic significance: YTMA423 (Yale, USA; n = 252) and CIMA-CUN (UNAV, Spain; n = 124), using QIF and DSP respectively.

Results: Using continuous log-scaled data, we found 5 markers independently associated with progression-free survival (PFS) in the tumor compartment (including PD-L1, p = 0.002). Among the novel candidate predictors, tumor cell CD44, a marker of pluripotency and stemness, was associated with longer PFS (multivariate HR = 0.63, p= 0.002). Using QIF, we orthogonally validated that CD44 expression in the tumor compartment was associated with longer PFS (p &lt;0.001) and overall survival (OS) (p = 0.03). In the external validation cohort, CD44 expressed in the tumor compartment, but not in the immune compartment, was predictive of clinical benefit (OR 1.22, p = 0.018), and was significantly associated with longer PFS (first tertile cutpoint: HR 0.62, p = 0.03). In contrast, high CD44 expression was not associated with survival in the two untreated cohorts. Using DSP data from two cohorts, regions of interest with elevated expression of CD44 in tumor cells consistently showed prominent (Fold Change&gt;1.5, p&lt;0.05) upregulation of TIM-3, and PD-L1 and multiple co-stimulatory molecules (including CD40, ICOS, CD27).

Conclusion: This work highlights CD44 as a novel indicative biomarker of sensitivity to PD-1 axis blockade in NSCLC. NSCLCs with high CD44 expression in epithelial cells may be associated with an immune contexture primed for higher response to immune checkpoint blockade. Further studies are needed to understand the interplay between CD44+ cancer stem cell phenotype and mechanisms of immune evasion.

Citation Format: Myrto Moutafi, Magdalena Molero, Sandra Martinez-Morilla, Javier Baena, Ioannis Vathiotis, Niki Gavrielatou, Laura Castro, Gorka Ruiz de Garibay, Vera Adradas, Daniel Orive, Karmele Valencia, Alfonso Galvo, Luis M. Montuenga, Santiago Ponce, Kurt Schalper, Luis Paz-Ares, David L. Rimm, Jon Zugazagoitia. Spatially resolved proteomic profiling identifies tumor cell CD44 as a novel indicative biomarker of sensitivity to PD-1 axis blockade in advanced non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2028.

Abstract 2027: Spatial omics and multiplexed imaging to discover new biomarkers of response or resistance to immune checkpoint inhibitors (ICI) in advanced non-small cell lung cancer (NSCLC)

Introduction: Despite the impressive outcomes with ICI in NSCLC, only a minority of the patients show long-term benefit from ICI. While PD-L1 immunohistochemistry is an approved companion diagnostic test, it is neither sensitive nor specific. Here, we describe the use of spatial transcriptomics using the GeoMx Digital Spatial Profiler (DSP) as a discovery platform to find biomarkers for ICI response or resistance.

Methods: Pre-treatment samples from 56 patients with NSCLC treated with ICI were collected and analyzed in a tissue microarray (TMA) format in two-fold redundancy. The human whole transcriptome, represented by 18000 genes assessed by oligonucleotide-tagged in situ hybridization, was sequenced on the NovaSeq platform to quantify the mRNAs present in each region of interest. Three molecularly defined tissue compartments, defined by fluorescence co-localization (tumor [panCK+], leukocytes [CD45+/CD68-], macrophages [CD68+]) were generated to assess mRNA. All statistical testing was performed using a two-sided significance level of α=0.05.

Result: 54000 gene variables were generated per case, from them about 27000 were analyzed after removing targets with expression lower than a prespecified frequency. Expression distribution of EPCAM in tumor, PTPRC in leukocytes and CD68 in macrophages confirmed that DSP successfully profiled the molecular compartments. Differential gene expression (DEG) analysis was performed for 6-month clinical benefit across two distinct tumor TMA spots per patient. This resulted in a DEG list of about 250, 125 and 122 genes in CK, CD45 and CD68 compartment respectively. When we used the intersection of significantly associated with benefit genes the candidate list was reduced dramatically to 5, 10 and 10 distinct genes in CK (CYBA, ESD, SH3BGRL3, TOP2B, UFM1), CD45 (ATRN, DGAT1, DNAAF9, GMPS, IFT20, MPHOSPH6, PKP4, SOCS2, TFAP4, TGFB3) and CD68 (ANKS3, ARFRP1, CTSD, DPYD, GTF3C5, HS2ST1, KIAA0895L, PIGR, SFTPA2, YEATS4) compartment respectively. From them, using the Cox Proportional-Hazards Model we further identified CYBA, ESD and UFM1 in CK, DGAT1 and IFT20 in CD45 and ANKS3 and DPYD in CD68 to predict survival as well.

Conclusions: Using DSP technology allows rapid, patient-specific assessment of the transcriptome in TMAs by in situ hybridization in spatially defined molecular compartments. Here we show a small set of candidate genes that are associated with outcome in this ICI-treated cohort. By intersecting two non-adjacent cores of the same patient tissue sample, we have begun to dissect tumor heterogeneity and pilot biomarker candidate information with unique molecularly defined compartments for tumor cells, lymphocytes, and macrophages. Results from this cohort may lead to a novel, spatially defined, transcriptomic approach for developing new biomarkers for immunotherapy.

Citation Format: Myrto Moutafi, Sandra Martinez-Morilla, Rolando Garcia-Milian, Thazin Nwe Aung, Ioannis Vathiotis, Niki Gavrielatou, Vasiliki Xirou, Leonidas Salichos, David L. Rimm. Spatial omics and multiplexed imaging to discover new biomarkers of response or resistance to immune checkpoint inhibitors (ICI) in advanced non-small cell lung cancer (NSCLC) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2027.

Abstract 1242: PD-L1 and PD-L2 mRNA are associated with outcome and high negative predictive value in immunotherapy-treated non-small cell lung cancer

Background: Immune checkpoint inhibitors (ICIs) are a class of immunotherapy that enhance a patient’s anti-cancer immune response, but only a small percentage of patients who are treated respond. This means patients who do not respond undergo costly and side effect-inducing treatment for no benefit indicating a need for improved selection criteria. Current predictive biomarkers include immunohistochemical (IHC) detection of PD-L1 but are insufficient for determining who will respond or, more importantly in the adjuvant setting, who will not respond.

Methods: This study utilizes a research use only (RUO*) quantitative real-time reverse transcription polymerase chain reaction assay, the GeneXpert® (GX) PD-L1 panel prototype assay, to test for the association between 4 target immune genes, CD274 (PD-L1), PDCD1LG2 (PD-L2), CD8A, and IRF1, and response to ICI therapy. Tissues were collected from 122 patients with advanced non-small cell lung cancer prior to ICI therapy in a retrospective cohort, macro-dissected, and analyzed using the PD-L1 prototype assay. Lysates were run on the GX instrument using the PD-L1 prototype assay. Individual transcripts were quantitated for each sample and the association with response was assessed. Median mRNA expression was used as a cutpoint to look at survival, clinical response and positive and negative predictive value (PPV, NPV). Optimal cutpoint was determined using Rstudio to also assess PPV and NPV. This study was approved by Yale Human Investigation IRB protocol ID 9505008219.

Results: Both high PD-L1 and PD-L2 mRNA, defined by median, were associated with improved long-term benefit at 24-months (PD-L1, p=0.0416; PD-L2, p=0.0435) and overall survival (PD-L1, p=0.047; PD-L2, p=0.047). Furthermore, low PD-L1 mRNA, defined by optimal cutpoint, showed a negative predictive value of 0.92.

Conclusions: High PD-L1 and PD-L2 mRNA, measured by GX, are associated with improved long-term benefit and overall survival. Importantly, low PD-L1 mRNA has a high negative predictive value. Given the simplicity and reproducibility of the GX system, with further validation this assay could be an improved method for selecting patients for treatment in the advanced setting, or more importantly, to determine which low stage patients should not be treated in the adjuvant setting. *For research use only. Not for use in diagnostic procedures.

Citation Format: Aileen I. Fernandez, Niki Gavrielatou, Leena McCann, Saba Shafi, Myrto K. Moutafi, Sandra Martinez-Morilla, Ioannis Vathiotis, Thazin Nwe Aung, Vesal Yaghoobi, Yalai Bai, Jodi Weidler, Michael Bates, David L. Rimm. PD-L1 and PD-L2 mRNA are associated with outcome and high negative predictive value in immunotherapy-treated non-small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 1242.

Digital spatial profiling to uncover biomarkers of immunotherapy outcomes in head and neck squamous cell carcinoma

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Background: Immunotherapy (ITx) has become the standard of care in the treatment of recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC). However, response rate is limited to 13-18% of patients, underlining the need to identify mechanisms implicated in response or resistance. This study aims to uncover novel biomarkers of ITx outcomes in R/M HNSCC using digital spatial profiling (DSP) technology. Methods: Pre-treatment biopsy samples of 50 ITx-treated R/M HNSCC patients, constructed in the form of tissue microarray (YTMA496), were included in our discovery cohort. Cases underwent DSP with the Human Immuno-Oncology protein panel (NanoString Technologies), comprising 71 photocleavable oligonucleotide-labeled primary antibodies, used for target-protein quantification in 4 distinct molecularly defined compartments: tumor (CK+), leukocyte (CD45+), macrophage (CD68+) and immune stroma (CD45+/CD68+). All markers were explored for associations with progression-free (PFS) and overall survival (OS) using a univariate Cox regression model. Significant markers were validated using an alternative quantitative immunofluorescence method as well as in an independent validation cohort of 29 ITx-treated R/M HNSCC cases (YTMA523). Results: Univariate DSP data analysis revealed high beta2-microglobulin (B2M), LAG-3, CD25 and 4-1BB in tumor, high B2M, CD45 and CD4 in stroma, and low fibronectin in the macrophage compartment, as markers associated with improved PFS. Increased levels of B2M and CD25 in tumor and CD11c in stroma were also correlated with prolonged OS. Focusing on B2M, cases at the top tertile of tumor B2M expression were associated with improved PFS and OS [HR, 0.43; 95% confidence interval (CI), 0.21-0.9; p = 0.034 and HR, 0.41; 95% CI, 0.18-0.90; p = 0.047, respectively], by an orthogonal QIF method. Findings were replicated in our validation cohort for PFS [HR, 0.41; 95% CI, 0.19-0.93; p = 0.034] and showed a similar trend for OS [HR, 0.44; 95% CI, 0.19-1.0; p = 0.074]. B2M-high tumors also had significant enrichment with immune-cell markers (CD3, CD4, CD8, CD11c, CD68 and CD163) and increased immune checkpoint expression (PD-L1, ICOS, TIM-3, LAG-3, IDO1, B7-H3), predominantly in the tumor compartment. Conclusions: Our study indicates that intact, highly functional antigen presentation, sustained by high B2M expression in tumor, confers survival benefit in ITx treated R/M HNSCC patients, an effect driven by increased intra-tumoral immunogenicity.

HER2 Aberrations in Non-Small Cell Lung Cancer: From Pathophysiology to Targeted Therapy

While human epidermal growth factor receptor 2 (HER2) aberrations have long been described in patients with non-small cell lung cancer (NSCLC), they have only recently been effectively targeted. Unlike patients with breast cancer, NSCLC patients can harbor either HER2-activating mutations or HER2 amplification coupled with protein overexpression. The latter has also been the case for patients with acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs). As preclinical data continue to accumulate, clinical trials evaluating novel agents that target HER2 have produced promising preliminary results. Here, we review existing data on HER2 aberrations in NSCLC. Starting from HER2 biology in normal and disease processes, we summarize discrepancies in HER2 diagnostic assays between breast cancer and NSCLC. Finally, to dissect the therapeutic implications of HER2-activating mutations versus gene amplification and/or protein overexpression, we present data from prospective clinical trials that have employed distinct classes of agents to target HER2 in patients with NSCLC.

240 Discovery of biomarkers of resistance to immune checkpoint blockade in non-small-cell lung cancer (NSCLC) using high-plex digital spatial profiling

Background

Despite the clinical effectiveness of Immune Checkpoint Inhibitors (ICI) in lung cancer, only around 20% remain disease free at 5 years. Predictive biomarkers for ICIs are neither sensitive nor specific. Here, we used the GeoMx Digital Spatial Profiler (DSP) (NanoString, Inc.) to analyze high-plex protein in a quantitative and spatially resolved manner from single formalin-fixed paraffin embedded tissue sections toward the goal of identification of new biomarkers with better predictive value.

Methods

Pre-treatment samples from 56 patients with NSCLC treated with ICI were collected, represented in Yale tissue microarray 471 (YTMA471), and analyzed. A panel of 71 photocleavable oligonucleotide-labeled primary antibodies (NanoString Human IO panel) was used for protein detection. Protein expression was measured in 4 molecularly defined tissue compartments, defined by fluorescence co-localization (tumor [panCK+], leukocytes [CD45+/CD68-], macrophages [CD68+] and an aggregate stromal immune cell compartment, defined as the sum of leukocyte and macrophage expression [panCK-/CD45+/CD68+]) generating 284 variables representing potential predictive biomarkers. Promising candidates were orthogonally validated with Quantitative Immunofluorescence (QIF). Pre-treatment samples from 40 patients with NSCLC (YTMA404) that received ICI, and 174 non-ICI treated operable NSCLC patients (YTMA423) were analyzed to provide independent cohort validation. All statistical testing was performed using a two-sided significance level of α=0.05 and multiple testing correction (Benjamini-Hochberg method, FDR < 0.1).

Results

Initial biomarker discovery on 284 protein variables were generated by univariate analysis using continuous log-scaled data. High PD-L1 expression in tumor cells predicted longer survival (PFS; HR 0.67, p=0.017) and validated the training cohort. We found 4 markers associated with PFS, and 3 with OS in the stromal compartment. Of these, expression of CD66b in stromal immune cells predicted significantly shorter OS (HR 1.31, p=0.016) and shorter PFS (HR 1.24, p = 0.04). Tertile analysis using QIF on all three tissue cohorts for CD66b expression, assessed by QIF, showed that CD66b was indicative but not prognostic for survival [discovery cohort, YTMA471 (OS; HR 3.02, p=0.013, PFS; HR 2.38, p=0.023), validation cohort; YTMA404 (OS; HR 2.97, p=0.018, PFS; HR 1.85, p=0.1), non-ICI treated cohort YTMA423 (OS; HR 1.02, p>0.9, PFS; HR 0.72, p=0.4)].

Conclusions

Using the DSP technique, we have discovered that CD66b expressed in the stromal immune [panCK-/CD45+/CD68+] molecular compartment is associated with resistance to ICI therapy in NSCLC. This observation was validated by an orthogonal approach in an independent ICI treated NSCLC cohort. Since CD66b identifies neutrophils, further studies are warranted to characterize the role of neutrophils in ICI resistance.

Acknowledgements

Dr Moutafi is supported by a scholarship from the Hellenic Society of Medical Oncologists (HESMO)

Ethics Approval

All tissue samples were collected and used under the approval from the Yale Human Investigation Committee protocol #9505008219 with an assurance filed with and approved by the U.S. Department of Health and Human Services

The Role of B Cells in Head and Neck Cancer

Simple Summary

Host immunity has established its role in deciding the course of cancer evolution. As cellular and molecular components in the tumor microenvironment peripherally appear to be at a constant interplay, favoring either tumor control or progression, it is vital to decrypt the immunity elements, which demonstrate the potential to be harnessed towards cancer elimination. Head and neck cancer has been characterized as densely immune infiltrated but at the same time a highly immunosuppressive malignancy due to a negative equilibrium between active and dysfunctional immune cell populations. B-cells constitute the cornerstone of humoral immunity; however, their role in cancer has been vastly overlooked in comparison to other immune subtypes and reports from multiple studies fail to show agreement on their prognostic impact. This review focuses on the role of B-cells on head and neck cancer with the aim to highlight their effect on anti-cancer immunity, as well as their possible impact on immunotherapy outcomes.

Abstract

Head and neck cancer comprises a heterogenous, highly immune infiltrated malignancy, defined by a predominantly immunosuppressive tumor microenvironment (TME). In recent years, PD-1/PD-L1 immune checkpoint inhibitors have become the standard of care treatment, either as monotherapy or in combination with chemotherapy agents, thus revolutionizing the therapeutic landscape of recurrent/metastatic disease. As a result, preclinical research is increasingly focusing on TME composition and pathophysiology, aiming to comprehensively characterize the specific elements and interactions affecting anti-tumor immunity, as well as to unveil novel predictive biomarkers of immunotherapy outcomes. While T lymphocytic populations have been vastly explored regarding their effect on cancer development, B-cells constitute a far less investigated, yet possibly equally important, aspect of cancer immunity. B-cell presence, either as single cells or as part of tertiary lymphoid structures within the TME, has been associated with several anti-tumor defense mechanisms, such as antigen presentation, antibody production and participation in antibody-dependent cellular cytotoxicity, and has demonstrated prognostic significance for multiple types of malignancies. However, immunoregulatory B-cell phenotypes have also been identified both peripherally and within malignant tissue, bearing inhibitory effects on numerous immune response processes. Consequently, B-cells and their subsets demonstrate the potential to become valuable cancer biomarkers and acquire a leading role in future therapeutic strategies.

Association of PD-1/PD-L1 Co-location with Immunotherapy Outcomes in Non-Small Cell Lung Cancer

PURPOSE

Programmed cell death protein 1(PD-1)/programmed death-ligand 1 (PD-L1) interaction suppresses local T cell responses and promotes peripheral tolerance. In the present study, we focus on PD-1/PD-L1 co-location as a surrogate for this interaction and assess its association with immunotherapy outcomes in patients with non-small cell lung cancer (NSCLC).

EXPERIMENTAL DESIGN

Pre-treatment biopsies from a retrospective cohort of 154 immunotherapy-treated patients with advanced NSCLC were analysed. Expression of PD-1 and PD-L1 was assessed by multiplexed quantitative immunofluorescence (QIF) and PD-1 expression in the same pixels as PD-L1 (called a co-location score) was measured using an algorithm to define overlapping expression areas. Co-location scores were correlated with immunotherapy outcomes and PD-L1 tumor proportion score.

RESULTS

PD-1/PD-L1 co-location score was associated with best overall response (p=0.0012), progression free survival (p=0.0341) and overall survival after immunotherapy (p=0.0249). The association was driven by patients receiving immune checkpoint inhibitors in the second or subsequent line of treatment. PD-L1 TPS by IHC was also correlated with best overall response and progression-free survival. PD-L1 measured within the tumor compartment by QIF did not show any significant association with either best overall response or overall survival. Finally, co-location score was not associated with PD-L1 expression by either method.

CONCLUSIONS

Based on our findings, co-location score shows promise as a biomarker associated with outcome after immunotherapy. With further validation, it could have value as a predictive biomarker for the selection of NSCLC patients receiving treatment with immune checkpoint inhibitors.

Quantitative immunofluorescence and mRNA analysis of immune-related biomarker groups in matched paired tumor samples from OPHELIA window study in head and neck squamous cell carcinoma (HNSCC)

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Background: Preclinical models suggest that PARP inhibitor-induced DNA damage can promote immune priming through a range of mechanisms including STING pathway activation. PARP inhibition also leads to adaptive upregulation of PD-L1 expression in preclinical models. To understand the distinct effects that different forms of DDR defects may have on tumor immunogenicity we decided to integrate genomic profiling with gene expression profiling and immunohistochemistry (IHC)/fluorescent assessments of PD-L1 expression, CD8 T-cell infiltration, and broad immune infiltrate, in order to define the overlap between DDR and immune-related biomarker groups and to build a deeper understanding of how DNA damage interfaces with antitumor immunity. Methods: 39 patients were enrolled in OPHELIA phase II trial in which pts were randomized 3:3:3:1 to Cisplatin (C) 60 mg/m2 on d1 followed by Olaparib (O) 75mg d 1-5 (Arm A), O 300 mg bid for 21-28 days (Arm B), no treatment (ARM C) or D 1500 mg on d1 followed by O 600 mg daily for 21-28 days (Arm D). PD-L1, STING, Ki67 and γ-H2AX were assessed using quantitative immunofluorescence (QIF). The GeneXpert (GX) closed system real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) was used for quantitative assessment of CD274 (PD-L1), PDCD1LG2 (PD-L2), CD8A, and IRF1 multiplex mRNA panel in pre- and post-treatment samples. Results: Ki67 was decreased in 23 out of 29 (79.3%) available samples when assessed by QIF; 13 / 23 had a decrease of at least 25%. Δγ-H2AX did not differ among treatment groups. A significant increase was observed in PD-L1 and PD-L2 mRNA levels after treatment with D-O (p = 0.023 and p = 0.016, respectively). An increase trend in posttreatment CD8A mRNA was observed in 23 out of 29 cases in the three treatment arms (p = 0.21, ARM A; p = 0.082, ARM B; p = 0.16, ARM D). IRF1 mRNA and STING protein levels were not upregulated after olaparib- based treatment in the available paired treatment samples. Conclusions: This window study demonstrated a significant upregulation of PD-L1 mRNA, corresponding to our previous data of increased Combined Positive Score (CPS) in the D-O arm post-treatment. Our findings suggest that addition of D to O leads to PD-L1 upregulation. Dual blockade of PARP and PD-1 can boost immune response and antitumor activity in HNSCC. Clinical trial information: NCT02882308.

Patterns of Response to Immune Checkpoint Inhibitors in Association with Genomic and Clinical Features in Patients with Head and Neck Squamous Cell Carcinoma (HNSCC)

Simple Summary

Immunotherapy agents, such as immune checkpoint inhibitors (ICIs), act through different mechanisms compared to conventional chemotherapy and are characterized by unique patterns of response, such as hyperprogression (HPD), which refers to the paradoxical acceleration of tumor growth kinetics (TGK). In this regard, we sought to compare patterns of response to ICIs with respect to clinical and genomic features in a cohort of patients with recurrent/metastatic head and neck squamous cell carcinoma (HNSCC). In our cohort, HPD was observed in 15.4% of patients. We report for the first time an association of HPD with both shorter progression free survival and overall survival in HNSCC. Importantly, in a multivariate Cox analysis, the presence of HPD remained an independent prognostic factor for survival. Primary site in the oral cavity and administration of ICI in the second/third setting were significant predictors of HPD in multivariate analysis. Genomic profiling revealed that gene amplification was more common in HPD patients.

Abstract

Background: We sought to compare patterns of response to immune checkpoint inhibitors (ICI) with respect to clinical and genomic features in a retrospective cohort of patients with recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC). Methods: One hundred seventeen patients with R/M HNSCC treated with ICI were included in this study. Tumor growth kinetics (TGK) prior to and TGK upon immunotherapy (IO) was available for 49 patients. The TGK ratio (TGKR, the ratio of tumor growth velocity before and upon treatment) was calculated. Hyperprogression (HPD) was defined as TGKR ≥ 2. Results: HPD was documented in 18 patients (15.4% of the whole cohort). Patients with HPD had statistically significant shorter progression free survival (PFS) (median PFS 1.8 months (95% CI, 1.03–2.69) vs. 6.1 months for patients with non-HPD (95% CI, 4.78–7.47), p = 0.0001) and overall survival (OS) (median OS 6.53 months (95% CI, 0–13.39) vs. 15 months in patients with non HPD (95% CI, 7.1–22.8), p = 0.0018). In a multivariate Cox analysis, the presence of HPD remained an independent prognostic factor (p = 0.049). Primary site in the oral cavity and administration of ICI in the second/third setting were significant predictors of HPD in multivariate analysis (p = 0.028 and p = 0.012, respectively). Genomic profiling revealed that gene amplification was more common in HPD patients. EGFR gene amplification was only observed in HPD patients, but the number of events was inadequate for the analysis to reach statistical significance. The previously described MDM2 amplification was not identified. Conclusions: HPD was observed in 15.4 % of patients with R/M HNSCC treated with IO and was associated with worse PFS and OS. EGFR amplification was identified in patients with HPD.

Association of autoimmunity with survival in patients with recurrent/metastatic head and neck squamous cell carcinoma treated with nivolumab

OBJECTIVES

Immune checkpoint inhibitors (ICIs) are associated with immune-related adverse events (irAEs) that occur as a consequence of enhanced immune response due to T-cell activation. The objective of this retrospective study was to investigate the association between irAEs and disease outcome in patients with recurrent/metastatic (R/M) head and neck squamous cell carcinoma (HNSCC).

MATERIALS AND METHODS

This study included 89 patients with R/M HNSCC who were treated with nivolumab in our center from October 2015 to January 2020. Overall survival (OS) and post-progression survival (PPS) were calculated from the date of nivolumab initiation or from the date of progression on nivolumab respectively to the date of death or censored at the last date of follow up.

RESULTS

Twenty-four patients (27%) developed irAEs, with more common thyroiditis (N = 13, 14.6%). ORR did not differ between patients with irAEs (29.2%) and patients without irAEs (21.9%, p = 0.576). Median PFS was similar between the two groups (3.1 months for patients with irAEs vs. 2.6 months for patients without irAEs, p = 0.412). Median OS was significantly longer in patients with irAEs (17.9 vs. 6.3 months in patients without irAEs, log-rank p = 0.004). Additionally, median PPS was significantly improved in patients who developed irAEs (10.2 months vs. 2.8 months for patients without irAEs, log-rank p = 0.001). In multivariate analysis, the development of irAEs and response to nivolumab were shown to be independent prognostic factors for favorable OS and PPS.

CONCLUSIONS

The development of irAEs is a strong predictor of improved survival in patients with advanced HNSCC treated with nivolumab.

Molecular correlates of response to preoperative olaparib alone or with cisplatin or with durvalumab in head and neck squamous cell carcinoma (HNSCC): A Hellenic Cooperative Oncology Group study

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Background: Poly(ADP-ribose) polymerase (PARP) inhibitors drive increased DNA damage and tumor cell death, particularly in tumors with existing defects in DNA repair. Furthermore,they promote immune priming, through a range of molecular mechanisms. Foremost, among candidate intracellular pathways is STING (stimulator of interferon genes), an innate immune response activated by cytosolic DNA (perhaps a consequence of DNA damage) that can lead to enhanced interferon (IFN) production. PARP inhibitor-induced DNA damage also leads to adaptive upregulation of programmed death ligand 1 (PD-L1) expression. To this end, there is increasing rationale for testing PARP inhibitors alone or in combination with chemotherapy or PD1 checkpoint inhibitors in HNSCC. Methods: 39 patients were enrolled in OPHELIA phase II trial in which pts were randomized 3:3:3:1 to Cisplatin (C) 60 mg/m2 on d1 followed by Olaparib (O) 75mg d 1-5 (Arm A), O 300 mg bid for 21-28 days (Arm B), no treatment (ARM C) orD 1500 mg on d1 followed by O 600 mg daily for 21-28 days (Arm D). Response was defined as tumor reduction noted on exam, imaging or pathology. Pretreatment biopsies were subjected to 310 gene OncoDNA NGS panel. Double Stranded Brakes/Repair (DSB/R) was measured by evaluating phosphorylation of histone H2AX by immunochistochemistry (IHC). In addition, IHC for PD-L1 (CPS) and STING was performed in paired pre- and post-treatment biopsies. Results: 17/36 pts in (O) treatment arms (6/11 evaluable pts Arm A, 9/11 evaluable pts Arm B, 2/11evaluable\ pts arm D) developed a response. One patient in D+O arm developed path CR. Low γH2AX staining at pretreatment biopsies was associated with progression (p=0.029). Higher PD-L1 expression (CPS≥1) was associated with disease progression (p=0.014). CPS PD-L1 was upregulated following (O) treatment. STING expression was not significantly upregulated post treatment in (O) treatment arms. Alterations in genes that have been previously reported to be associated with (O) sensitivity, namely DNA damage Response/Repair (DDR) genes and genes involved in chromatin remodeling ( CHK2, KMT2D, KMT2C, ARID2 and AJUBA), were identified in responders. Conclusions: This window study demonstrated promising signs of activity of (O) in HNSCC, particularly in tumors with high expression of γH2AX and alterations in DDR or chromatin remodeling genes. Clinical trial information: NCT02882308 .

Association of autoimmunity with survival in patients with recurrent/metastatic head and neck squamous cell carcinoma (R/M HNSCC) treated with immune checkpoint inhibitors (ICIs)

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Background: ICIs are associated with immune-related adverse events (irAEs) that occur as a consequence of enhanced immune response due to T-cell activation. The objective of this observational cohort study was to investigate the association between irAEs and disease outcome in pts with R/M HNSCC. Methods: 110 pts treated with ICIs were reviewed. Overall survival (OS) was calculated from the date of initiation of ICI to the date of death. To overcome guarantee-time bias, we calculated post-irAEs survival from the date of first irAE presentation in patients who developed irAEs or from the date of ICI initiation in pts without irAEs. Results: Primary site was the oral cavity (N = 51), oropharynx (N = 20), larynx (N = 29), hypopharynx (N = 1), paranasal sinuses (N = 5) and nasopharynx (N = 4). 41 (37.3%) had metastatic and 69 (62.7%) recurrent disease. 32 pts (29.1%) developed irAEs, with more common thyroiditis (N = 15, 13.6%). Of 100 pts with evaluable disease, 14 (14%) responded. 6/31 (19.4%) with irAEs vs. 8/69 (11.6%) without irAEs responded to ICI (p = 0.354). After a median follow-up of 16.4 months, 69 pts died. Median OS was 10 mo (95%CI, 6.7-13.4), 10 mo (95%CI, 5.6-14.5) for pts with recurrent and 10 mo (95%CI, 7.7-12.3) for pts with metastatic HNSCC (p = 0.966). Median OS was 17.9 mo (95%CI, 7.9-27.9) for pts with irAEs and 6.6 mo (95%CI, 3.3-9.9) for pts without irAEs (p = 0.001). Median post-irAEs survival was 16.3 (95%CI, 7.1-25.5) for pts with irAEs vs. 6.6 mo (95%CI, 3.3-9.9) for pts without irAEs (p = 0.020). Responders to ICI did not differ in median post-irAEs survival irrespective of whether they developed irAEs (p = 0.561), while among non-responders, those who developed irAEs had significantly longer median post-irAEs survival compared to those who did not (10 vs. 6 mo, respectively, p = 0.044). Multiviariate Cox proportional hazard models showed that independent favorable prognostic factors for post-irAEs survival were the development of irAEs (HR 0.54, 95%CI 0.30-0.97, p = 0.039) and response to ICI (HR 0.16, 95%CI 0.05-0.50, p = 0.002). Conclusions: The development of irAEs is a strong predictor of improved survival in patients with advanced HNSCC treated with ICIs.

Biomarkers for immunotherapy response in head and neck cancer

Preclinical data suggest that head and neck squamous cell carcinoma (HNSCC) is a profoundly immunosuppressive disease, characterized by abnormal secretion of proinflammatory cytokines and dysfunction of immune effector cells. Based on landmark phase III trials, two anti-Programmed Cell Death-1 (PD-1) antibodies, pembrolizumab and nivolumab have been approved for HNSCC by FDA and EMEA in the recurrent/metastatic setting; in addition, pembrolizumab has recently received FDA and EMEA approval as first line treatment. In clinical practice, only a minority of patients with HNSCC derive benefit from immunotherapy and the need for the discovery of novel biomarkers to optimize treatment strategies is becoming increasingly more relevant. Although currently only PD-L1 is widely used as a predictive biomarker for response to immune checkpoint inhibitors in HNSCC, there are many ongoing trials focusing on the identification of new biomarkers. This review will summarize current data on emerging biomarkers for response to immunotherapy in HNSCC.

Clinical implications of hyperprogression with immune checkpoint inhibitors in patients with head and neck squamous cell carcinoma (HNSCC)

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Background: Hyperprogressive disease (HPD) refers to paradoxical acceleration of tumor growth kinetics (TGK) after initiation of treatment with anti- PD-1/PD- L1 agents and has been reported across tumor types in 4-29% of patients using different definitions. Preliminary data suggest that HPD might affect response to subsequent therapies. Methods: We compared TGK prior and TGK upon immunotherapy (IO) in 62 patients (pts) with recurrent/metastatic (R/M) HNSCC treated with PD-1/PD-L1 inhibitors. The TGK ratio (TGKR, ratio of tumor growth velocity before and upon treatment) was calculated. The first imaging assessment was performed 3 months (mo) after IO initiation. HPD was defined as 1. Radiological HPD (TGKR≥2) or 2. Clinical HPD (Disease-related rapid clinical deterioration post IO). Results: After median follow-up of 12.3 mo (range, 0.4-28.1), 43 pts progressed and 38 died. Median PFS was 2.8 mo (95%CI, 2.2-3.4) and median OS 8.6 mo (95%CI, 4.2-12.9). HPD was observed in 16 pts (25.8%), while 15 pts had early PD (Time to Treatment failure, TTF < 3 mo) and 31 late PD (TTF > 3mo). Among 16 pts with HPD, 11 had radiological HPD and 10 had clinical HPD. 4 pts had both clinical and radiological HPD. Pts with late PD had median OS 11.3 mo (95%CI, 9.3-13.3), those with early PD 5.2 mo (95%CI, 3.1-7.3 months) and those with HPD 5.1 mo (95%CI, 4.4-5.9) (p < 0.005). Regarding post-progression OS, pts with late PD had median 11.3 mo (95%CI 0-22.8), those with early PD 2.5 mo (95%CI 0.6-4.4) and those with HPD 4.2 mo (95%CI 1.7-6.7) (p = 0.001). Pts with HPD had a trend for longer median post-progression OS compared to pts with early PD (p = 0.121). Median PFS with chemotherapy after immunotherapy failure was 3.0 mo (95%CI 2.4-3.6) for pts with late PD, 2.1 mo (95%CI 0.9-3.4) for pts with early PD and 6.1 mo (95%CI 3.0-9.3) for those with HPD (p = 0.040). HPD was associated with longer median PFS with chemotherapy compared to pts with early PD (p = 0.016), while the difference in median PFS with chemotherapy between pts with HPD and late progressors was non-statistically significant (p = 0.260). Conclusions: Radiological or clinical HPD was observed in 25.8% of patients with R/M HNSCC treated with IO. Early progression to immunotherapy is an important predictor of short survival, while HPD was associated with improved PFS to subsequent chemotherapy.

Predictive biomarkers for response to nivolumab in head and neck squamous cell carcinoma (HNSCC) (NCT#03652142)

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Background: Tumor immune cell compositions determine response to immunotherapy. For a better understanding of the mechanisms of resistance to nivolumab in HNSCC, we sought to investigate a prospective cohort of longitudinal HNSCC samples from recurrent/metastatic HNSCC pts treated with nivolumab and identify biomarkers of response and resistance. We will specifically focus on modulation of immune markers following two cycles of nivolumab. Methods: Patients with platinum-refractory HNSCC with no contraindication to nivolumab therapy are included in this study. Tumor biopsies are performed at baseline, 24-72 hours after the second cycle and at progression with appropriate written informed consent. Samples were assessed for the presence of Tertiary Lymphoid Structures (TLS), PD-L1 expression (TPS and CPS) and CD8 T cell infiltrates combined with Ki67 (CD8/Ki67 double IHC stain). The primary outcome measure of the study is change in the percentage of immune cells in post treatment compared to baseline biopsies. Secondary endpoints include safety of performing a second biopsy, best overall response rate, biomarker expression in association with response and survival. Evaluation of other biomarkers including tumor mutational burden, HLA class I and II expression and adaptive immunity cell populations using multiplex IF is ongoing. Results: Of 20 patients evaluable for response, 14 had PD (8 of whom showed hyper-progression) and 6 attained disease control (1 with PR). PD-L1 status (CPS or TPS) was not altered by treatment (p = 0.905) and CPS > 20 pre-treatment showed a favorable trend towards response (p = 0.117). Absence of tertiary lymphoid structures was associated with disease progression (p = 0.0374). Infiltrating plasma cell count remained unchanged pre- and post-treatment and was unrelated to response (p = 0.458). The percentage of proliferating CD8+ T cells (CD8+/Ki67+) increased in post-treatment biopsies in the entire population (p = 0.022) and especially in progressors (p = 0.039). Pre-treatment CD8+ T cell density was higher in patients with hyper-progression compared to progressors (p = 0.029). Conclusions: Increased percentage of proliferating CD8+ T cells in progressors might represent dysfunctional T cells as has been recently shown in melanoma pts (Li H et al Cell 2019) and clinical efforts to reactivate intratumoral T cells may augment the efficacy of PD1 checkpoint inhibitors. Clinical trial information: NCT03652142.