Integrative analysis reveals selective 9p24.1 amplification, increased PD-1 ligand expression, and further induction via JAK2 in nodular sclerosing Hodgkin lymphoma and primary mediastinal large B-cell lymphoma. Blood. 2010;116:3268-3277. [PMID: 20628145 DOI: 10.1182/blood-2010-05-282780]

Comprehensive characterization of programmed death ligand structural rearrangements in B-cell non-Hodgkin lymphomas

Capture sequencing reveals that PDL SRs cluster into 2 discrete breakpoint regions. PDL SRs are significantly associated with increased protein expression and limit T-cell activation.

Pembrolizumab in classical Hodgkin's lymphoma

Pembrolizumab is a humanized monoclonal antibody directed against programmed cell death protein 1 (PD-1), a key immune-inhibitory molecule expressed on T cells and implicated in CD4+ T-cell exhaustion and tumor immune-escape mechanisms. Classical Hodgkin's lymphoma (cHL) is a unique B-cell malignancy in the sense that malignant Reed-Sternberg (RS) cells represent a small percentage of cells within an extensive immune cell infiltrate. PD-1 ligands are upregulated on RS cells as a consequence of both chromosome 9p24.1 amplification and Epstein-Barr virus infection and by interacting with PD-1 promote an immune-suppressive effect. By augmenting antitumor immune response, pembrolizumab and nivolumab, another monoclonal antibody against PD-1, have shown significant activity in patients with relapsed/refractory cHL as well as an acceptable toxicity profile with immune-related adverse events that are generally manageable. In this review, we explore the rationale for targeting PD-1 in cHL, review the clinical trial results supporting the use of checkpoint inhibitors in this disease, and present future directions for investigation in which this approach may be used.

Programmed death-1 immune checkpoint blockade in the treatment of hematological malignancies

The use of tumor-specific monoclonal antibodies (MAbs) has revolutionize the field of cancer immunotherapy. Although treatment of malignant diseases with MAbs is promising, many patients fail to respond or relapse after an initial response. Both solid tumors and hematological malignancies develop mechanisms that enable them to evade the host immune system by usurping immune checkpoint pathways such as PD-1, PD-2, PDL-1, or PDL-2 (programmed cell death protein-1 or 2 and PD-Ligand 1 or 2), which are expressed on activated T cells and on T-regulatory, B cells, natural killers, monocytes, and dendritic cells. One of the most exciting anticancer development in recent years has been the immune checkpoint blockade therapy by using MAbs against immune checkpoint receptor and/or ligands. Anti-PD1 antibodies have been tested in clinical studies that included patients with hematological malignancies and showed remarkable efficacy in Hodgkin lymphoma (HL). In our review, we will focus on the effect of PD-1 activation on hematological malignancies and its role as a therapeutic target. Key messages The programmed death 1 (PD1) immune checkpoint is an important homeostatic mechanism of the immune system that helps in preventing autoimmunity and uncontrolled inflammation in cases of chronic infections. However, PD1 pathway is also operated by a wide variety of malignancies and represents one of the most important mechanisms by which tumor cells escape from the surveillance of the immune system. Blocking of immune checkpoints by the use of monoclonal antibodies opened a new era in the field of cancer immunotherapy. Results from clinical trials are promising, and currently, this approach has been proven effective and safe in patients with solid tumors and hematological malignancies.

Integrative systems medicine approaches to identify molecular targets in lymphoid malignancies

Although survival rates for lymphoproliferative disorders are steadily increasing both in the US and in Europe, there is need for optimizing front-line therapies and developing more effective salvage strategies. Recent advances in molecular genetics have highlighted the biological diversity of lymphoproliferative disorders. In particular, integrative approaches including whole genome sequencing, whole exome sequencing, and transcriptome or RNA sequencing have been instrumental to the identification of molecular targets for treatment. Herein, we will discuss how genomic, epigenomic and proteomic approaches in lymphoproliferative disorders have supported the discovery of molecular lesions and their therapeutic targeting in the clinic.

Regulatory circuits of T cell function in cancer

Recent progress in cancer immunotherapy emphasizes the importance of understanding immune-regulatory pathways in tumours. Dysfunction of antitumour T cells may be due to mechanisms that are evolutionarily conserved or acquired by somatic mutations. The dysfunctional state of T cells has been termed 'exhaustion', on the basis of similarities to dysfunctional T cells in chronic infections. However, despite shared properties, recent studies have identified marked differences between T cell dysfunction in cancer and chronic infection. In this Review, we discuss T cell-intrinsic molecular alterations and metabolic communication in the tumour microenvironment. Identification of the underlying molecular drivers of T cell dysfunction is essential for the continued progress of cancer research and therapy.

PD-L1 Detection in Tumors Using [(64)Cu]Atezolizumab with PET

The programmed death protein 1 (PD-1) and programmed death-ligand 1 (PD-L1) pair is a major immune checkpoint pathway exploited by cancer cells to develop and maintain immune tolerance. With recent approvals of anti-PD-1 and anti-PD-L1 therapeutic antibodies, there is an urgent need for noninvasive detection methods to quantify dynamic PD-L1 expression in tumors and to evaluate the tumor response to immune modulation therapies. To address this need, we assessed [(64)Cu]atezolizumab for the detection of PD-L1 expression in tumors. Atezolizumab (MPDL3208A) is a humanized, human and mouse cross-reactive, therapeutic PD-L1 antibody that is being investigated in several cancers. Atezolizumab was conjugated with DOTAGA and radiolabeled with copper-64. The resulting [(64)Cu]atezolizumab was assessed for in vitro and in vivo specificity in multiple cell lines and tumors of variable PD-L1 expression. We performed PET-CT imaging, biodistribution, and blocking studies in NSG mice bearing tumors with constitutive PD-L1 expression (CHO-hPD-L1) and in controls (CHO). Specificity of [(64)Cu]atezolizumab was further confirmed in orthotopic tumor models of human breast cancer (MDAMB231 and SUM149) and in a syngeneic mouse mammary carcinoma model (4T1). We observed specific binding of [(64)Cu]atezolizumab to tumor cells in vitro, correlating with PD-L1 expression levels. Specific accumulation of [(64)Cu]atezolizumab was also observed in tumors with high PD-L1 expression (CHO-hPD-L1 and MDAMB231) compared to tumors with low PD-L1 expression (CHO, SUM149). Collectively, these studies demonstrate the feasibility of using [(64)Cu]atezolizumab for the detection of PD-L1 expression in different tumor types.

Suppressor of cytokine signaling 1 gene mutation status as a prognostic biomarker in classical Hodgkin lymphoma

Suppressor of cytokine signaling 1 (SOCS1) mutations are among the most frequent somatic mutations in classical Hodgkin lymphoma (cHL), yet their prognostic relevance in cHL is unexplored. Here, we performed laser-capture microdissection of Hodgkin/Reed-Sternberg (HRS) cells from tumor samples in a cohort of 105 cHL patients. Full-length SOCS1 gene sequencing showed mutations in 61% of all cases (n = 64/105). Affected DNA-motifs and mutation pattern suggest that many of these SOCS1 mutations are the result of aberrant somatic hypermutation and we confirmed expression of mutant alleles at the RNA level. Contingency analysis showed no significant differences of patient-characteristics with HRS-cells containing mutant vs. wild-type SOCS1. By predicted mutational consequence, mutations can be separated into those with non-truncating point mutations (‘minor’ n = 49/64 = 77%) and those with length alteration (‘major’; n = 15/64 = 23%). Subgroups did not differ in clinicopathological characteristics; however, patients with HRS-cells that contained SOCS1 major mutations suffered from early relapse and significantly shorter overall survival (P = 0.03). The SOCS1 major status retained prognostic significance in uni-(P = 0.016) and multivariate analyses (P = 0.005). Together, our data indicate that the SOCS1 mutation type qualifies as a single-gene prognostic biomarker in cHL.

Low Frequency of Programmed Death Ligand 1 Expression in Pediatric Cancers

Programmed death 1 (PD-1)/programmed death ligand 1 (PD-L1) pathway blockade has become a promising therapeutic target in adult cancers. We evaluated PD-L1 expression and tumor-infiltrating CD8(+) T cells in formalin-fixed, paraffin-embedded tumor specimens from 53 untreated pediatric patients with eight cancer types: neuroblastoma, extracranial malignant germ cell tumor, hepatoblastoma, germinoma, medulloblastoma, renal tumor, rhabdomyosarcoma, and atypical teratoid/rhabdoid tumor. One rhabdomyosarcoma with the shortest survival exhibited membranous PD-L1 expression and germinoma contained abundant tumor-infiltrating CD8(+) T cells and PD-L1-positive macrophages. The PD-1/PD-L1 pathway tended to be inactive in pediatric cancers.

Immune-checkpoint expression in Epstein-Barr virus positive and negative plasmablastic lymphoma: a clinical and pathological study in 82 patients

Plasmablastic lymphoma is a rare and aggressive diffuse large B-cell lymphoma commonly associated with Epstein-Barr virus co-infection that most often occurs in the context of human immunodeficiency virus infection. Therefore, its immune escape strategy may involve the upregulation of immune-checkpoint proteins allowing the tumor immune evasion. However, the expression of these molecules was poorly studied in this lymphoma. We have investigated 82 plasmablastic lymphoma cases of whom half were Epstein-Barr virus positive. Although they harbored similar pathological features, Epstein-Barr virus positive plasmablastic lymphomas showed a significant increase in MYC gene rearrangement and had a better 2-year event-free survival than Epstein-Barr virus negative cases (P=0.049). Immunostains for programmed cell death-1, programmed cell death-ligand 1, indole 2,3-dioxygenase and dendritic cell specific C-type lectin showed a high or moderate expression by the microenvironment cells in 60%-72% of cases, whereas CD163 was expressed in almost all cases. Tumor cells also expressed programmed cell death-1 and its ligand in 22.5% and 5% of cases, respectively. Both Epstein-Barr virus positive and negative plasmablastic lymphomas exhibited a high immune-checkpoint score showing that it involves several pathways of immune escape. However, Epstein-Barr virus positive lymphomas exhibited a higher expression of programmed cell death-1 and its ligand in both malignant cells and microenvironment as compared to Epstein-Barr virus negative cases. In conclusion, plasmablastic lymphoma expresses immune-checkpoint proteins through both malignant cells and the tumor microenvironment. The expression of programmed cell death-1 and its ligand constitutes a strong rationale for testing monoclonal antibodies in this often chemoresistant disease.

Genomic amplification of 9p24.1 targeting JAK2, PD-L1, and PD-L2 is enriched in high-risk triple negative breast cancer

We used DNA content flow cytometry followed by oligonucleotide array based comparative genomic hybridization to survey the genomes of 326 tumors, including 41 untreated surgically resected triple negative breast cancers (TNBC). A high level (log2ratio ≥ 1) 9p24 amplicon was found in TNBC (12/41), glioblastomas (2/44), and colon carcinomas (2/68). The shortest region of overlap for the amplicon targets 9p24.1 and includes the loci for PD-L1, PD-L2, and JAK2 (PDJ amplicon). In contrast this amplicon was absent in ER+ (0/8) and HER2+ (0/15) breast tumors, and in pancreatic ductal adenocarcinomas (0/150). The PDJ amplicon in TNBCs was correlated with clinical outcomes in group comparisons by two-sample t-tests for continuous variables and chi-squared tests for categorical variables. TNBC patients with the PDJ amplicon had a worse outcome with worse disease-free and overall survival. Quantitative RT-PCR confirmed that the PDJ amplicon in TNBC is associated with elevated expression of JAK2 and of the PD-1 ligands. These initial findings demonstrate that the PDJ amplicon is enriched in TNBC, targets signaling pathways that activate the PD-1 mediated immune checkpoint, and identifies patients with a poor prognosis.

Magneto-nanosensor platform for probing low-affinity protein-protein interactions and identification of a low-affinity PD-L1/PD-L2 interaction

Substantial efforts have been made to understand the interactions between immune checkpoint receptors and their ligands targeted in immunotherapies against cancer. To carefully characterize the complete network of interactions involved and the binding affinities between their extracellular domains, an improved kinetic assay is needed to overcome limitations with surface plasmon resonance (SPR). Here, we present a magneto-nanosensor platform integrated with a microfluidic chip that allows measurement of dissociation constants in the micromolar-range. High-density conjugation of magnetic nanoparticles with prey proteins allows multivalent receptor interactions with sensor-immobilized bait proteins, more closely mimicking natural-receptor clustering on cells. The platform has advantages over traditional SPR in terms of insensitivity of signal responses to pH and salinity, less consumption of proteins and better sensitivities. Using this platform, we characterized the binding affinities of the PD-1-PD-L1/PD-L2 co-inhibitory receptor system, and discovered an unexpected interaction between the two known PD-1 ligands, PD-L1 and PD-L2.

Nivolumab for classical Hodgkin's lymphoma after failure of both autologous stem-cell transplantation and brentuximab vedotin: a multicentre, multicohort, single-arm phase 2 trial

BACKGROUND

Malignant cells of classical Hodgkin's lymphoma are characterised by genetic alterations at the 9p24.1 locus, leading to overexpression of PD-1 ligands and evasion of immune surveillance. In a phase 1b study, nivolumab, a PD-1-blocking antibody, produced a high response in patients with relapsed and refractory classical Hodgkin's lymphoma, with an acceptable safety profile. We aimed to assess the clinical benefit and safety of nivolumab monotherapy in patients with classical Hodgkin's lymphoma after failure of both autologous stem-cell transplantation and brentuximab vedotin.

METHODS

In this ongoing, single-arm phase 2 study, adult patients (aged ≥18 years) with recurrent classical Hodgkin's lymphoma who had failed to respond to autologous stem-cell transplantation and had either relapsed after or failed to respond to brentuximab vedotin, and with an Eastern Cooperative Oncology Group performance status score of 0 or 1, were enrolled from 34 hospitals and academic centres across Europe and North America. Patients were given nivolumab intravenously over 60 min at 3 mg/kg every 2 weeks until progression, death, unacceptable toxicity, or withdrawal from study. The primary endpoint was objective response following a prespecified minimum follow-up period of 6 months, assessed by an independent radiological review committee (IRRC). All patients who received at least one dose of nivolumab were included in the primary and safety analyses. This trial is registered with ClinicalTrials.gov, number NCT02181738.

FINDINGS

Among 80 treated patients recruited between Aug 26, 2014, and Feb 20, 2015, the median number of previous therapies was four (IQR 4-7). At a median follow-up of 8·9 months (IQR 7·8-9·9), 53 (66·3%, 95% CI 54·8-76·4) of 80 patients achieved an IRRC-assessed objective response. The most common drug-related adverse events (those that occurred in ≥15% of patients) included fatigue (20 [25%] patients), infusion-related reaction (16 [20%]), and rash (13 [16%]). The most common drug-related grade 3 or 4 adverse events were neutropenia (four [5%] patients) and increased lipase concentrations (four [5%]). The most common serious adverse event (any grade) was pyrexia (three [4%] patients). Three patients died during the study; none of these deaths were judged to be treatment related.

INTERPRETATION

Nivolumab resulted in frequent responses with an acceptable safety profile in patients with classical Hodgkin's lymphoma who progressed after autologous stem-cell transplantation and brentuximab vedotin. Therefore, nivolumab might be a new treatment option for a patient population with a high unmet need. Ongoing follow-up will help to assess the durability of response.

FUNDING

Bristol-Myers Squibb.

Nivolumab for classical Hodgkin's lymphoma after failure of both autologous stem-cell transplantation and brentuximab vedotin: a multicentre, multicohort, single-arm phase 2 trial

BACKGROUND

Malignant cells of classical Hodgkin's lymphoma are characterised by genetic alterations at the 9p24.1 locus, leading to overexpression of PD-1 ligands and evasion of immune surveillance. In a phase 1b study, nivolumab, a PD-1-blocking antibody, produced a high response in patients with relapsed and refractory classical Hodgkin's lymphoma, with an acceptable safety profile. We aimed to assess the clinical benefit and safety of nivolumab monotherapy in patients with classical Hodgkin's lymphoma after failure of both autologous stem-cell transplantation and brentuximab vedotin.

METHODS

In this ongoing, single-arm phase 2 study, adult patients (aged ≥18 years) with recurrent classical Hodgkin's lymphoma who had failed to respond to autologous stem-cell transplantation and had either relapsed after or failed to respond to brentuximab vedotin, and with an Eastern Cooperative Oncology Group performance status score of 0 or 1, were enrolled from 34 hospitals and academic centres across Europe and North America. Patients were given nivolumab intravenously over 60 min at 3 mg/kg every 2 weeks until progression, death, unacceptable toxicity, or withdrawal from study. The primary endpoint was objective response following a prespecified minimum follow-up period of 6 months, assessed by an independent radiological review committee (IRRC). All patients who received at least one dose of nivolumab were included in the primary and safety analyses. This trial is registered with ClinicalTrials.gov, number NCT02181738.

FINDINGS

Among 80 treated patients recruited between Aug 26, 2014, and Feb 20, 2015, the median number of previous therapies was four (IQR 4-7). At a median follow-up of 8·9 months (IQR 7·8-9·9), 53 (66·3%, 95% CI 54·8-76·4) of 80 patients achieved an IRRC-assessed objective response. The most common drug-related adverse events (those that occurred in ≥15% of patients) included fatigue (20 [25%] patients), infusion-related reaction (16 [20%]), and rash (13 [16%]). The most common drug-related grade 3 or 4 adverse events were neutropenia (four [5%] patients) and increased lipase concentrations (four [5%]). The most common serious adverse event (any grade) was pyrexia (three [4%] patients). Three patients died during the study; none of these deaths were judged to be treatment related.

INTERPRETATION

Nivolumab resulted in frequent responses with an acceptable safety profile in patients with classical Hodgkin's lymphoma who progressed after autologous stem-cell transplantation and brentuximab vedotin. Therefore, nivolumab might be a new treatment option for a patient population with a high unmet need. Ongoing follow-up will help to assess the durability of response.

FUNDING

Bristol-Myers Squibb.

Mutational Landscape and Sensitivity to Immune Checkpoint Blockers

Immunotherapy is currently transforming cancer treatment. Notably, immune checkpoint blockers (ICB) have shown unprecedented therapeutic successes in numerous tumor types, including cancers that were traditionally considered as nonimmunogenic. However, a significant proportion of patients do not respond to these therapies. Thus, early selection of the most sensitive patients is key, and the development of predictive companion biomarkers constitutes one of the biggest challenges of ICB development. Recent publications have suggested that the tumor genomic landscape, mutational load, and tumor-specific neoantigens are potential determinants of the response to ICB and can influence patients' outcomes upon immunotherapy. Furthermore, defects in the DNA repair machinery have consistently been associated with improved survival and durable clinical benefit from ICB. Thus, closely reflecting the DNA damage repair capacity of tumor cells and their intrinsic genomic instability, the mutational load and its associated tumor-specific neoantigens appear as key predictive paths to anticipate potential clinical benefits of ICB. In the era of next-generation sequencing, while more and more patients are getting the full molecular portrait of their tumor, it is crucial to optimally exploit sequencing data for the benefit of patients. Therefore, sequencing technologies, analytic tools, and relevant criteria for mutational load and neoantigens prediction should be homogenized and combined in more integrative pipelines to fully optimize the measurement of such parameters, so that these biomarkers can ultimately reach the analytic validity and reproducibility required for a clinical implementation. Clin Cancer Res; 22(17); 4309-21. ©2016 AACR.

Racial patterns of patients with primary mediastinal large B-cell lymphoma: SEER analysis

The aim of this study is to investigate the incidence and clinical outcomes of primary mediastinal large B-cell lymphoma (PMBL).Here we did a retrospective analysis using the surveillance, epidemiology, and end results (SEER) database to analyze the incidences and survival of patients with PMBL diagnosed during 2001-2012 among major ethnic groups.During 2001-2012, a total of 426 PMBL patients were identified, including 336 whites, 46 blacks, and 44 others. The incidence rates of female to male ratios in white, black, and other were 1.4938, 1.1202, and 1.7303 respectively, suggesting that the female-prominent disease occurrence was seen only in whites and others, but not in black population. Compared to white, the other had a worse 5-year overall survival (OS); however, factors including age, race, socioeconomic status, and stage associated with OS showed no significant difference among ethnic groups; thus, biology factors should be explored to explain the racial difference in OS.In conclusion, our findings revealed diversities in demographic features and prognosis among different racial groups.

The immune microenvironment in Hodgkin lymphoma: T cells, B cells, and immune checkpoints

Classical Hodgkin lymphoma is curable in the majority of cases with chemotherapy and/or radiation. However, 15-20% of patients ultimately relapse and succumb to their disease. Pathologically, classical Hodgkin lymphoma is characterized by rare tumor-initiating Reed-Sternberg cells surrounded by a dense immune microenvironment. However, the role of the immune microenvironment, particularly T and B cells, in either promoting or restricting Classical Hodgkin lymphoma growth remains undefined. Recent dramatic clinical responses seen using monoclonal antibodies against PD-1, a cell surface receptor whose primary function is to restrict T cell activation, have reignited questions regarding the function of the adaptive immune system in classical Hodgkin lymphoma. This review summarizes what is known regarding T cells, B cells, and immune checkpoints in classical Hodgkin lymphoma.

Recent Advances in Aggressive Large B-cell Lymphomas: A Comprehensive Review

Diffuse large B-cell lymphoma (DLBCL) is an aggressive disease with considerable heterogeneity reflected in the 2008 World Health Organization classification. In recent years, genome-wide assessment of genetic and epigenetic alterations has shed light upon distinct molecular subsets linked to dysregulation of specific genes or pathways. Besides fostering our knowledge regarding the molecular complexity of DLBCL types, these studies have unraveled previously unappreciated genetic lesions, which may be exploited for prognostic and therapeutic purposes. Following the last World Health Organization classification, we have witnessed the emergence of new variants of specific DLBCL entities, such as CD30 DLBCL, human immunodeficiency virus-related and age-related variants of plasmablastic lymphoma, and EBV DLBCL arising in young patients. In this review, we will present an update on the clinical, pathologic, and molecular features of DLBCL incorporating recently gained information with respect to their pathobiology and prognosis. We will emphasize the distinctive features of newly described or emerging variants and highlight advances in our understanding of entities presenting a diagnostic challenge, such as T-cell/histiocyte-rich large B-cell lmphoma and unclassifiable large B-cell lymphomas. Furthermore, we will discuss recent advances in the genomic characterization of DLBCL, as they may relate to prognostication and tailored therapeutic intervention. The information presented in this review derives from English language publications appearing in PubMed throughout December 2015. For a complete outline of this paper, please visit: http://links.lww.com/PAP/A12.

Genetic basis of PD-L1 overexpression in diffuse large B-cell lymphomas

Translocations between PD-L1 and the IGH locus represent a genetic mechanism of PD-L1 overexpression in DLBCL. Genetic alterations in the PD-L1/PDL-2 locus are mainly associated with the non-GCB subtype of DLBCL.

Emerging therapies provide new opportunities to reshape the multifaceted interactions between the immune system and lymphoma cells

The acquisition of a complete neoplastic phenotype requires cancer cells to develop escape mechanisms from the host immune system. This phenomenon, commonly referred to as 'immune evasion,' represents a hallmark of cancers and results from a Darwinian selection of the fittest tumor clones. First reported in solid tumors, cancer immunoescape characterizes several hematological malignancies. The biological bases of cancer immunoescape have recently been disclosed and include: (i) impaired human leukocyte antigen-mediated cancer cell recognition (B2M, CD58, CTIIA, CD80/CD86, CD28 and CTLA-4 mutations); (ii) deranged apoptotic mechanisms (reduced pro-apoptotic signals and/or increased expression of anti-apoptotic molecules); and (iii) changes in the tumor microenvironment involving regulatory T cells and tumor-associated macrophages. These immune-escape mechanisms characterize both Hodgkin and non-Hodgkin (B and T cell) lymphomas and represent a promising target for new anti-tumor therapies. In the present review, the principles of cancer immunoescape and their role in human lymphomagenesis are illustrated. Current therapies targeting these pathways and possible applications for lymphoma treatment are also addressed.

Novel agents for the treatment of Hodgkin lymphoma

Hodgkin lymphoma (HL) is highly curable lymphoma with combined multiagent chemotherapy with or without radiation. In spite of higher cure rates, approximately 20-30% cases will be either refractory or relapse after first line therapy. For relapse/refractory HL, salvage chemotherapy followed by autologous stem cell transplant remains the standard of care. Because of early and late toxicities of multiagent chemotherapy, there are ongoing efforts to find less toxic therapies to treat HL. Brentuximab vedotin is an antibody drug conjugate targeting CD30 with high response rates in HL. In the last decade, immune oncology has changed the treatment paradigm of cancers. Biologically, Reed-Sternberg cells evade immune system by exploiting checkpoint pathways. Inhibition of checkpoint pathway has shown promising activity in HL. Recently, phosphatidyl-inositide 3 kinase inhibitors and Janus kinase inhibitors have shown impressive responses in HL. In this article, we discuss novel agents in HL.

Nivolumab in Patients With Relapsed or Refractory Hematologic Malignancy: Preliminary Results of a Phase Ib Study

PURPOSE

Cancer cells can exploit the programmed death-1 (PD-1) immune checkpoint pathway to avoid immune surveillance by modulating T-lymphocyte activity. In part, this may occur through overexpression of PD-1 and PD-1 pathway ligands (PD-L1 and PD-L2) in the tumor microenvironment. PD-1 blockade has produced significant antitumor activity in solid tumors, and similar evidence has emerged in hematologic malignancies.

METHODS

In this phase I, open-label, dose-escalation, cohort-expansion study, patients with relapsed or refractory B-cell lymphoma, T-cell lymphoma, and multiple myeloma received the anti-PD-1 monoclonal antibody nivolumab at doses of 1 or 3 mg/kg every 2 weeks. This study aimed to evaluate the safety and efficacy of nivolumab and to assess PD-L1/PD-L2 locus integrity and protein expression.

RESULTS

Eighty-one patients were treated (follicular lymphoma, n = 10; diffuse large B-cell lymphoma, n = 11; other B-cell lymphomas, n = 10; mycosis fungoides, n = 13; peripheral T-cell lymphoma, n = 5; other T-cell lymphomas, n = 5; multiple myeloma, n = 27). Patients had received a median of three (range, one to 12) prior systemic treatments. Drug-related adverse events occurred in 51 (63%) patients, and most were grade 1 or 2. Objective response rates were 40%, 36%, 15%, and 40% among patients with follicular lymphoma, diffuse large B-cell lymphoma, mycosis fungoides, and peripheral T-cell lymphoma, respectively. Median time of follow-up observation was 66.6 weeks (range, 1.6 to 132.0+ weeks). Durations of response in individual patients ranged from 6.0 to 81.6+ weeks.

CONCLUSION

Nivolumab was well tolerated and exhibited antitumor activity in extensively pretreated patients with relapsed or refractory B- and T-cell lymphomas. Additional studies of nivolumab in these diseases are ongoing.

Current and future immunotherapeutic approaches in Hodgkin lymphoma

Hodgkin lymphoma (HL) has become a highly curable malignancy even in advanced stages when treated adequately. However, relapsed or refractory disease and treatment-related toxicity constitute a significant clinical challenge. Innovative approaches are thus needed to improve treatment of these mainly young patients. In HL lesions, very few malignant Hodgkin and Reed-Sternberg (HRS) cells are embedded in an immunosuppressive microenvironment of reactive cells. Novel approaches such as bispecific antibodies, antibody-drug conjugates, immune-checkpoint inhibitors or adoptive cellular therapies are currently being investigated with promising results in relapsed or refractory patients. Encouraging response rates and a favorable toxicity profile have recently been reported in early phase clinical trials with antibodies blocking the programed-death receptor 1 (PD1). This review will summarize the current clinical knowledge on mechanism, safety and efficacy of the different agents and discuss potential future strategies, which are partly already investigated within clinical trials.

Pan-cancer analysis of copy number changes in programmed death-ligand 1 (PD-L1, CD274) - associations with gene expression, mutational load, and survival

Inhibition of the PD-L1 (CD274) - PD-1 axis has emerged as a powerful cancer therapy that prevents evasion of tumor cells from the immune system. While immunohistochemical detection of PD-L1 was introduced as a predictive biomarker with variable power, much less is known about copy number alterations (CNA) affecting PD-L1 and their associations with expression levels, mutational load, and survival. To gain insight, we employed The Cancer Genome Atlas (TCGA) datasets to comprehensively analyze 22 major cancer types for PD-L1 CNAs. We observed a diverse landscape of PD-L1 CNAs, which affected focal regions, chromosome 9p or the entire chromosome 9. Deletions of PD-L1 were more frequent than gains (31% vs. 12%) with deletions being most prevalent in melanoma and non-small cell lung cancer. Copy number gains most frequently occurred in ovarian cancer, head and neck cancer, bladder cancer, cervical and endocervical cancer, sarcomas, and colorectal cancers. Fine-mapping of the genetic architecture revealed specific recurrently amplified and deleted core regions across cancers with putative biological and clinical consequences. PD-L1 CNAs correlated significantly with PD-L1 mRNA expression changes in many cancer types, and tumors with PD-L1 gains harbored significantly higher mutational load compared to non-amplified cases (median: 78 non-synonymous mutations vs. 40, P = 7.1e-69). Moreover, we observed that, in general, both PD-L1 amplifications and deletions were associated with dismal prognosis. In conclusion, PD-L1 CNAs, in particular PD-L1 copy number gains, represent frequent genetic alterations across many cancers, which influence PD-L1 expression levels, are associated with higher mutational loads, and may be exploitable as predictive biomarker for immunotherapy regimens. © 2016 Wiley Periodicals, Inc.

Aberrant PD-L1 expression through 3'-UTR disruption in multiple cancers

Successful treatment of many patients with advanced cancer using antibodies against programmed cell death 1 (PD-1; also known as PDCD1) and its ligand (PD-L1; also known as CD274) has highlighted the critical importance of PD-1/PD-L1-mediated immune escape in cancer development. However, the genetic basis for the immune escape has not been fully elucidated, with the exception of elevated PD-L1 expression by gene amplification and utilization of an ectopic promoter by translocation, as reported in Hodgkin and other B-cell lymphomas, as well as stomach adenocarcinoma. Here we show a unique genetic mechanism of immune escape caused by structural variations (SVs) commonly disrupting the 3' region of the PD-L1 gene. Widely affecting multiple common human cancer types, including adult T-cell leukaemia/lymphoma (27%), diffuse large B-cell lymphoma (8%), and stomach adenocarcinoma (2%), these SVs invariably lead to a marked elevation of aberrant PD-L1 transcripts that are stabilized by truncation of the 3'-untranslated region (UTR). Disruption of the Pd-l1 3'-UTR in mice enables immune evasion of EG7-OVA tumour cells with elevated Pd-l1 expression in vivo, which is effectively inhibited by Pd-1/Pd-l1 blockade, supporting the role of relevant SVs in clonal selection through immune evasion. Our findings not only unmask a novel regulatory mechanism of PD-L1 expression, but also suggest that PD-L1 3'-UTR disruption could serve as a genetic marker to identify cancers that actively evade anti-tumour immunity through PD-L1 overexpression.

Secondary B-cell lymphoma associated with the Epstein-Barr virus in chronic lymphocytic leukemia patients

Up to 10 % of chronic lymphocytic leukemia (CLL) patients present with aggressive secondary B-cell lymphoma (most frequently diffuse large B-cell lymphoma, DLBCL) which may be clonally related to the CLL (i.e., Richter transformation, RT, 80 % of the cases) or de novo (20 % of the cases). Several genetic lesions associated with RT have already been identified, but the potential role of the Epstein-Barr virus (EBV) has been largely overlooked. In this study, we describe six CLL patients who developed a secondary EBV-positive (EBV⁺) B-cell lymphoma (five DLBCL, one Hodgkin lymphoma) and compare their clinicopathological characteristics to ten CLL patients with EBV-negative (EBV^-) secondary B-cell lymphomas (all DLBCL). All 16 patients had a history of iatrogenic immunosuppression or chemotherapy. Eighty percent had received fludarabine as part of the CLL treatment. Most secondary lymphomas were clonally related to the previous CLL (3/4 EBV⁺, 7/7 EBV^- cases tested). Notably EBV⁺ RT was associated with a trend for older age at onset (median 72 vs. 63 years, p value >0.05), longer interval between CLL and RT diagnosis (median 4.2 vs. 2.9 years, p value >0.05), and shorter overall survival (median 4 vs. 10 months, p value >0.05). These differences were not significant, probably due to small sample size. Immunohistochemical profiling suggested more frequent overexpression of TP53 and MYC in EBV^- compared to EBV⁺ secondary lymphoma. Based on this small retrospective single center series, we hypothesize that EBV⁺ RT may constitute a separate subgroup of RT. Larger series are required to validate this suggestion.

Immunomodulatory antibodies for the treatment of lymphoma: Report on the CALYM Workshop

In November 2015, the CALYM Carnot Institute held a 2-d workshop to discuss the current and future development of immunomodulatory antibodies for the treatment of lymphoma. Highlights from the workshop are presented in this article.

Role of the tumor microenvironment in regulating apoptosis and cancer progression

Apoptosis is a gene-directed program that is engaged to efficiently eliminate dysfunctional cells. Evasion of apoptosis may be an important gate to tumor initiation and therapy resistance. Like any other developmental program, apoptosis can be disrupted by several genetic aberrations driving malignant cells into an uncontrolled progression and survival. For its sustained growth, cancer develops in a complex environment, which provides survival signals and rescues malignant cells from apoptosis. Recent studies have clearly shown a wide interaction between tumor cells and their microenvironment, confirming the influence of the surrounding cells on tumor expansion and invasion. These non-malignant cells not only intensify tumor cells growth but also upgrade the process of metastasis. The strong crosstalk between malignant cells and a reactive microenvironment is mediated by soluble chemokines and cytokines, which act on tumor cells through surface receptors. Disturbing the microenvironment signaling might be an encouraging approach for patient's treatment. Therefore, the ultimate knowledge of "tumor-microenvironment" interactions facilitates the identification of novel therapeutic procedures that mobilize cancer cells from their supportive cells. This review focuses on cancer progression mediated by the dysfunction of apoptosis and by the fundamental relationship between tumor and reactive cells. New insights and valuable targets for cancer prevention and therapy are also presented.

Hodgkin lymphoma: Pathology and biology

The Hodgkin and Reed-Sternberg (HRS) tumor cells of classical Hodgkin lymphoma (HL), as well as the lymphocyte predominant (LP) cells of nodular lymphocyte predominant HL (NLPHL), are derived from mature B cells. However, HRS cells have largely lost their B-cell phenotype and show a very unusual expression of many markers of other hematopoietic cell lineages, which aids in the differential diagnosis between classical HL (cHL) and NLPHL and distinguishes cHL from all other hematopoietic malignancies. The bi- or multinucleated Reed-Sternberg cells most likely derive from the mononuclear Hodgkin cells through a process of incomplete cytokinesis. HRS cells show a deregulated activation of numerous signaling pathways, which is partly mediated by cellular interactions in the lymphoma microenvironment and partly by genetic lesions. In a fraction of cases, Epstein-Barr virus contributes to the pathogenesis of cHL. Recurrent genetic lesions in HRS cells identified so far often involve members of the nuclear factor-κB (NF-κB) and JAK/STAT pathways and genes involved in major histocompatibility complex expression. However, further lead transforming events likely remain to be identified. We here discuss the current knowledge on HL pathology and biology.

Prognostic Value of Programmed Death Ligand 1 and Programmed Death 1 Expression in Thymic Carcinoma

PURPOSE

The immune checkpoint of the programmed death 1/programmed death ligand 1 (PD-1/PD-L1) pathway is believed to play an important role in evasion of host antitumor immune surveillance in various malignancies; however, little is known about its role in thymic carcinoma. This study investigated PD-1/PD-L1 expression and its association with clinicopathologic features, the expression of immune-related proteins in tumor-infiltrating lymphocytes (TIL), and patient prognosis.

EXPERIMENTAL DESIGN

PD-L1 and PD-1 expression was evaluated by IHC in 25 thymic carcinoma tissue specimens. Copy number alterations of the PD-L1 gene in 11 cases were assessed in formalin-fixed, paraffin-embedded material using qRT-PCR.

RESULTS

Compared with normal subjects, 3 thymic carcinoma patients showed an increase in PD-L1 copy number, whereas 8 did not. PD-L1 was significantly overexpressed in cases with copy number gain as compared with normal cases. High PD-L1 expression was associated with higher disease-free and overall survival rates as compared to cases with low expression. Prognostic analysis revealed low PD-L1 expression and high number of PD-1(+) TILs as significant predictors of poor survival, together with Masaoka-Koga stage IVa/IVb disease and incomplete resection. In the quantitative analysis of TILs, PD-L1 expression correlated proportionally with the number of infiltrating CTLs.

CONCLUSIONS

Here, for the first time, we report that PD-L1 and PD-1 expression might be useful prognostic predictors in thymic carcinoma. Further studies are expected to substantiate the prognostic value of PD-L1 and PD-1 expression, and the potential efficacy of targeting the PD-1/PD-L1 pathway in thymic carcinoma via immunotherapy. Clin Cancer Res; 22(18); 4727-34. ©2016 AACR.

Targeting the programmed death-1/programmed death-ligand 1 axis in lymphoma

PURPOSE OF REVIEW

The development of 'immune checkpoint inhibitors' or drugs targeting the programmed death-1 (PD-1)/programmed death-ligand 1 (PD-L1) axis has been a stunning success of cancer immunotherapy. This review provides a timely overview of the biology and function of the PD-1 pathway and discusses the rationale for therapeutic inhibition of this pathway in lymphoma.

RECENT FINDINGS

Recent studies have evaluated the prevalence and prognostic implications of PD-1, PD-L1/2 expression in various lymphoma subtypes. We present an overview of the clinical trials evaluating pidilizumab, nivolumab, and pembrolizumab in patients with lymphoid malignancies, and highlight some of the more promising agents in this class, currently in development. Finally, we discuss biomarkers that may predict response to therapy in patients with lymphoma across these clinical trials.

SUMMARY

A plethora of clinical trials are in progress testing immune checkpoint inhibitors in many subtypes of lymphoma, which will define their role both as a monotherapy and in combination with other biologic agents.

PD-L1 expression in non-small cell lung cancer: Correlations with genetic alterations

Inhibition of the PD-1/PD-L1 pathway may induce anticancer immune responses in non-small cell lung cancer (NSCLC). Two PD-L1 immunohistochemistry (IHC) assays have been approved as companion diagnostic tests for therapeutic anti-PD-1 antibodies. However, many aspects of PD-L1 prevalence and association with genetically defined subtypes have not been addressed systematically. Here, we analyzed PD-L1 expression in 436 genetically annotated NSCLC specimens enriched for early stages using PD-L1 antibody 5H1. Expression of PD-L1 was detected in the tumor cells (TC) (34% of cases) and in associated immune cells (IC) (49%) across all stages of NSCLC, either alone or in combination. PD-L1 IHC-positive TC, but not IC showed significantly higher PD-L1 RNA expression levels. Expression in TC was associated with TP53, KRAS and STK11 mutational status in adenocarcinomas (AD) and with NFE2L2 mutations in squamous cell carcinomas (SQ). No correlations with histological subtype, clinical characteristics and overall survival were found. The presence of PD-L1-positive IC was significantly associated with patients' smoking status in AD. The findings are in agreement with the emerging concept that tumors with high mutational burden are more likely to benefit from immunotherapy, since TP53 and KRAS mutations are linked to smoking, increased numbers of somatic mutations and expression of neoantigens. Current clinical studies focus on stage IIIB and IV NSCLC; however, PD-L1 expression occurs in earlier stages and might be a predictive biomarker in clinical trials testing (neo-) adjuvant strategies.

Mechanism-driven biomarkers to guide immune checkpoint blockade in cancer therapy

With recent approvals for multiple therapeutic antibodies that block cytotoxic T lymphocyte associated antigen 4 (CTLA4) and programmed cell death protein 1 (PD1) in melanoma, non-small-cell lung cancer and kidney cancer, and additional immune checkpoints being targeted clinically, many questions still remain regarding the optimal use of drugs that block these checkpoint pathways. Defining biomarkers that predict therapeutic effects and adverse events is a crucial mandate, highlighted by recent approvals for two PDL1 diagnostic tests. Here, we discuss biomarkers for anti-PD1 therapy based on immunological, genetic and virological criteria. The unique biology of the CTLA4 immune checkpoint, compared with PD1, requires a different approach to biomarker development. Mechanism-based insights from such studies may guide the design of synergistic treatment combinations based on immune checkpoint blockade.

Immune checkpoint blockade: Releasing the brake towards hematological malignancies

Tumor cells utilize co-inhibitory molecules to avoid host immune destruction. Checkpoint blockade has emerged as a promising approach to treat cancer by restoring T cell effector function and breaking a tumor permissive microenvironment. Patients with hematological malignancies often have immune dysregulation, thus the role of checkpoint blockade in treatment of these neoplasms is particularly intriguing. In early trials, antibodies targeting cytotoxic T lymphocyte antigen 4 (CTLA-4) or the programmed death 1 (PD-1) signaling pathway have displayed significant efficacy with minimal toxicity in patients with relapsed and refractory hematological neoplasms. In this review, we provide evidence of dysregulation of CTLA-4 and PD-1/PD-Ls in the context of several major types of hematological neoplasms and summarize relevant clinical practice points for checkpoint blockade. The preclinical rationale and preliminary clinical data of potential combination approaches designed to optimize checkpoint antagonists are well presented.

Recurrent genetic defects in classical Hodgkin lymphoma cell lines

Genetic analysis of classical Hodgkin lymphoma (cHL) has been hampered by the paucity of Hodgkin cells in biopsies and their poor growth in vitro. However, a wealth of information has been obtained from cHL cell lines. Here we report results of whole-exome sequencing and karyotypic analysis of five cHL cell lines. Four genes with potentially pathogenic single nucleotide variants (SNV) were detected in three cell lines. SNV were also detected in seventeen HL-related genes and three mitosis-related genes. Copy number variants were detected in four HL-related genes in all five cell lines. Given the high degree of aneuploidy in HL, mitosis-related genes were screened for defects. One mitotic gene (NCAPD2) was amplified in all five HL cell lines, and two genes (FAM190A, PLK4) were amplified in four cell lines. These results suggest that genomic instability of HL may be due to defects in genes involved in chromosome duplication and segregation.

PD-L1 and PD-L2 Genetic Alterations Define Classical Hodgkin Lymphoma and Predict Outcome

PURPOSE

Classical Hodgkin lymphomas (cHLs) include small numbers of malignant Reed-Sternberg cells within an extensive but ineffective inflammatory/immune cell infiltrate. In cHL, chromosome 9p24.1/PD-L1/PD-L2 alterations increase the abundance of the PD-1 ligands, PD-L1 and PD-L2, and their further induction through Janus kinase 2-signal transducers and activators of transcription signaling. The unique composition of cHL limits its analysis with high-throughput genomic assays. Therefore, the precise incidence, nature, and prognostic significance of PD-L1/PD-L2 alterations in cHL remain undefined.

METHODS

We used a fluorescent in situ hybridization assay to evaluate CD274/PD-L1 and PDCD1LG2/PD-L2 alterations in 108 biopsy specimens from patients with newly diagnosed cHL who were treated with the Stanford V regimen and had long-term follow-up. In each case, the frequency and magnitude of 9p24.1 alterations-polysomy, copy gain, and amplification-were determined, and the expression of PD-L1 and PD-L2 was evaluated by immunohistochemistry. We also assessed the association of 9p24.1 alterations with clinical parameters, which included stage (early stage I/II favorable risk, early stage unfavorable risk, advanced stage [AS] III/IV) and progression-free survival (PFS).

RESULTS

Ninety-seven percent of all evaluated cHLs had concordant alterations of the PD-L1 and PD-L2 loci (polysomy, 5% [five of 108]; copy gain, 56% [61 of 108]; amplification, 36% [39 of 108]). There was an association between PD-L1 protein expression and relative genetic alterations in this series. PFS was significantly shorter for patients with 9p24.1 amplification, and the incidence of 9p24.1 amplification was increased in patients with AS cHL.

CONCLUSION

PD-L1/PD-L2 alterations are a defining feature of cHL. Amplification of 9p24.1 is more common in patients with AS disease and associated with shorter PFS in this series. Further analyses of 9p24.1 alterations in patients treated with standard cHL induction regimens or checkpoint blockade are warranted.

BCR-JAK2 fusion in a myeloproliferative neoplasm with associated eosinophilia

Janus kinase 2 (JAK2) is located on chromosome 9 at band p24 and JAK2V617F is the most common mutation in Philadelphia chromosome-negative myeloproliferative neoplasms (Ph-MPN). However, rearrangement of JAK2 is a rare event. We report a case of myeloproliferative neoplasm, unclassifiable (MPN-U) with BCR-JAK2 fusion confirmed by molecular studies. Conventional chromosome analysis (CC) revealed t(9;22)(p24;q11.2) and fluorescence in situ hybridization (FISH) showed a JAK2 gene rearrangement in 88% of interphase nuclei. The BCR-JAK2 fusion was confirmed by multiplex reverse transcriptase polymerase chain reaction (RT-PCR) and demonstrated two in-frame 5'BCR/3'JAK2 transcripts with BCR exon 1 juxtaposed to JAK2 exon 15 and exon 17, respectively. Our results, together with literature review, reveal BCR-JAK2 fusions as oncogenic genetic alterations that are associated with myeloid or lymphoid neoplasms and are frequently characterized by eosinophilia. Further, patients with BCR-JAK2 are candidates for JAK2 inhibitor therapy. Given the distinct clinical and pathological characteristics, we believe that hematological neoplasms harboring BCR-JAK2 should be included as an additional distinct entity to the current WHO category of "myeloid and lymphoid neoplasms with eosinophilia and abnormalities of PDGFRA, PDGFRB, or FGFR", and testing for a JAK2 fusion should be pursued in neoplasms with a karyotypic 9p24 abnormality.

PD-L1 expression is associated with tumor-infiltrating T cells and favorable prognosis in high-grade serous ovarian cancer

OBJECTIVE

As a negative regulator of T cells, Programmed Death Ligand 1 (PD-L1) is both an indicator and inhibitor of anti-tumor immune responses, which has led to confusion about its prognostic significance. We investigated the primary source of PD-L1 expression in epithelial ovarian cancer and its relationship to tumor-infiltrating lymphocytes (TIL) and associated gene products.

METHODS

Tissue microarrays containing high-grade serous carcinomas (HGSC) and endometrioid, clear cell and mucinous ovarian cancers from optimally debulked patients were assessed by immunohistochemistry for expression of PD-L1 and other markers (CD68, CD3, CD8, PD-1, CD103, FoxP3 and CD25). The Cancer Genome Atlas was interrogated for associations between PD-L1 expression and immune-related transcriptional and genomic features of HGSC.

RESULTS

PD-L1 was primarily expressed by tumor-associated CD68(+) macrophages rather than tumor cells. PD-L1(+) cells frequently co-localized with CD8, CD4 and PD-1(+) TIL, CD25(+)FoxP3(+) Tregs, and other TIL subsets. PD-L1(+) cells were prognostically favorable in HGSC. Moreover, the presence of both PD-L1(+) cells and CD8 TIL was associated with better prognosis than CD8 TIL alone. PD-L1 gene expression was independent of BRCA status. At the transcriptional level, PD-L1 was associated with both cytolytic (granzyme B, T-bet and IFN-γ) and suppressive (PD-1, CTLA-4, LAG3 and IDO-1) gene products.

CONCLUSIONS

PD-L1 is primarily expressed by macrophages in ovarian cancer and is strongly associated with both cytolytic and regulatory TIL subsets, resulting in a net positive association with survival. Tumors containing PD-L1(+) macrophages appear caught in an immunological stalemate that may require multi-pronged immunotherapy to alleviate.

Lymphoma Microenvironment and Immunotherapy

Understanding of the lymphoma tumor microenvironment is poised to expand in the era of next-generation sequencing studies of the tumor cells themselves. Successful therapies of the future will rely on deeper appreciation of the interactions between elements of the microenvironment. Although the phenotypic, cytogenetic, and molecular characterization of tumor cells in lymphomas has progressed faster than most other solid organ tumors, concrete advancements in understanding the lymphoma microenvironment have been fewer. This article explores the composition of the lymphoma tumor microenvironment; its role in immune surveillance, evasion, and drug resistance; and its potential role in the development of targeted therapies.

Expression and prognostic roles of PIK3CA, JAK2, PD-L1, and PD-L2 in Epstein-Barr virus-associated gastric carcinoma

As a special subtype of gastric carcinoma, Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) has distinct clinicopathological features. The Cancer Genome Atlas Research Network revealed that EBVaGC also has distinct molecular features: PIK3CA mutations, DNA hypermethylation, and JAK2, PD-L1, and PD-L2 amplification. Here, we evaluated PIK3CA, JAK2, PD-L1, and PD-L2 expression in 59 EBVaGC and 796 EBV-negative gastric carcinoma (EBVnGC) cases using immunohistochemistry and found that PIK3CA, JAK2, PD-L1, and PD-L2 were highly expressed in 75.9% and 48.8% (P<.001), 81.8% and 71.1% (P=.091), 92.5% and 84.8% (P=.132), and 98.1% and 89.7% (P=.049) of the EBVaGC and EBVnGC cases, respectively. However, the expression of PIK3CA, JAK2, PD-L1, or PD-L2 was not significantly associated with clinicopathological features or patient outcomes in EBVaGC. In contrast, in EBVnGC, high PIK3CA expression was significantly associated with indolent clinicopathological features and independently predicted better 5-year overall survival (57.8% versus 33.4%, P<.001). Our study indicated that the protein expression of the 4 characteristic molecules of EBVaGC was basically consistent with their genetic alterations, making them potential characteristic protein biomarkers and therapeutic targets of EBVaGC. The favorable impact of PIK3CA overexpression on survival found in this study gives us new insight into the clinical significance of PIK3CA in EBVnGC.

Immune checkpoint pathways: perspectives on myeloid malignancies

Immunologic tolerance to cancer has recently been shown to have major implications for the ability of tumors to survive despite a variety of therapeutic approaches. A critical mechanism underlying this microenvironment dysfunction relates to the ability of tumor cells to block immune check points through expression of specific proteins that interfere with immune cell effector function. Recent advances based on this model have led translational work showing therapeutic efficacy in a variety of solid and lymphoid tumors. Myeloid malignancies, in particular myelodysplastic syndromes (MDS), have significant immune dysregulation of variable degree based on their clinical stages which makes feasible extending such therapeutic approaches to this group of diseases. This review will discuss recent advances in the field of immune checkpoint biology including recent clinical trials with checkpoint inhibitors in patients with a variety of clinical conditions, with focus on such potential therapy in patients with myeloid malignancies.

Coinhibitory Pathways in Immunotherapy for Cancer

The immune system is capable of recognizing tumors and eliminates many early malignant cells. However, tumors evolve to evade immune attack, and the tumor microenvironment is immunosuppressive. Immune responses are regulated by a number of immunological checkpoints that promote protective immunity and maintain tolerance. T cell coinhibitory pathways restrict the strength and duration of immune responses, thereby limiting immune-mediated tissue damage, controlling resolution of inflammation, and maintaining tolerance to prevent autoimmunity. Tumors exploit these coinhibitory pathways to evade immune eradication. Blockade of the PD-1 and CTLA-4 checkpoints is proving to be an effective and durable cancer immunotherapy in a subset of patients with a variety of tumor types, and additional combinations are further improving response rates. In this review we discuss the immunoregulatory functions of coinhibitory pathways and their translation to effective immunotherapies for cancer.

Reprint of: Fast Cars and No Brakes: Autologous Stem Cell Transplantation as a Platform for Novel Immunotherapies

Autologous stem cell transplantation (ASCT) is indicated in a number of hematologic malignancies, including multiple myeloma, non-Hodgkin lymphoma, and Hodgkin lymphoma. Relapse, however, remains 1 of the main causes of post-ASCT failure, and several strategies are being investigated to decrease the risk of relapse of progression. Recent advances in the treatment of hematological malignancies have included adoptive transfer of genetically modified T cells that express chimeric antigen receptors or T cell receptors, as well the use of checkpoint inhibitors. Early clinical results in non-transplantation patients have been very promising. This review will focus on the use of gene-modified T cells and checkpoint inhibitors in stem cell transplantation.

Immune checkpoint modulation for non-small cell lung cancer

Therapies targeting immune checkpoints have recently shown encouraging activity in patients with heavily pretreated advanced non-small cell lung cancer (NSCLC), independently of NSCLC histology or mutational status, with low toxicity profiles when used as monotherapy. Objective response rates of approximately 20% have been reported in patients with advanced NSCLC treated with antagonist antibodies targeting the immune checkpoint, programmed death 1 (PD-1) on activated T cells, or its primary ligand, programmed death ligand 1 (PD-L1) expressed within the tumor microenvironment. Response rates appear to be higher in patients with tumor PD-L1 expression documented by immunohistochemistry, although responses have been appreciated in patients with reportedly PD-L1-negative tumor specimens. Antibodies directed against cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), another immunosuppressive T-cell signaling molecule, are also being evaluated in clinical trials, with one randomized phase II trial demonstrating improved immune-related progression-free survival in lung cancer patients when added to standard chemotherapy. Additional clinical trials are combining anti-CTLA-4 antibodies with either anti-PD-1 or anti-PD-L1 antibodies. Combinations of other immune checkpoint antagonists or agonist antibodies with anti-PD-1 or anti-PD-L1 antibodies are also being pursued.