Safety, activity, and immune correlates of anti-PD-1 antibody in cancer

"License to kill" reflects joint action of CD4 and CD8 T cells

The spontaneous T-cell responses to the KIF20A cancer-associated antigen found by Tomita and colleagues among peripheral blood mononuclear cells of patients with cancer, but not healthy people, involve both CD4 and CD8 T cells. Synthetic long peptides of KIF20A stimulate synergy between these two T-cell types to promote cancer cell killing.

Update on the challenges and recent advances in cancer immunotherapy

This overview provides an analysis of some of the immunotherapies currently in use and under investigation, with a special focus on the tumor microenvironment, which we believe is a major factor responsible for the general failure of immunotherapy to date. It is our expectation that combining immunotherapy with methods of altering the tumor microenvironment and targeting regulatory T cells and myeloid cells will yield favorable results.

Cutting edge: Prolonged exposure to HIV reinforces a poised epigenetic program for PD-1 expression in virus-specific CD8 T cells

Ag-specific CD8 T cells play a critical role in controlling HIV infection but eventually lose antiviral functions in part because of expression and signaling through the inhibitory programmed death-1 (PD-1) receptor. To better understand the impact of prolonged TCR ligation on regulation of PD-1 expression in HIV-specific CD8 T cells, we investigated the capacity of virus-specific CD8 T cells to modify the PD-1 epigenetic program after reduction in viral load. We observed that the transcriptional regulatory region was unmethylated in the PD-1(hi) HIV-specific CD8 T cells, whereas it remained methylated in donor-matched naive cells at acute and chronic stages of infection. Surprisingly, the PD-1 promoter remained unmethylated in HIV-specific CD8 T cells from subjects with a viral load controlled by antiviral therapy for >2 y or from elite controllers. Together, these data demonstrate that the epigenetic program at the PD-1 locus becomes fixed after prolonged exposure to HIV virus.

Immunity of human epithelial ovarian carcinoma: the paradigm of immune suppression in cancer

Epithelial ovarian cancer (EOC) is a significant cause of cancer-related mortality in women, and there has been no substantial decrease in the death rates due to EOC in the last three decades. Thus, basic knowledge regarding ovarian tumor cell biology is urgently needed to allow the development of innovative treatments for EOC. Traditionally, EOC has not been considered an immunogenic tumor, but there is evidence of an immune response to EOC in patients. Clinical data demonstrate that an antitumor immune response and immune evasion mechanisms are correlated with a better and lower survival, respectively, providing evidence for the immunoediting hypothesis in EOC. This review focuses on the immune response and immune suppression in EOC. The immunological roles of chemotherapy and surgery in EOC are also described. Finally, we detail pilot data supporting the efficiency of immunotherapy in the treatment of EOC and the emerging concept that immunomodulation aimed at counteracting the immunosuppressive microenvironment must be associated with immunotherapy strategies.

Adoptive T-cell transfer in melanoma

Immunotherapy holds a highly promising treatment approach for metastatic melanoma patients. Adoptive cell transfer (ACT) involves the ex vivo expansion of autologous antitumor reactive lymphocytes and their reinfusion into lymphodepleted patients, accompanied by IL-2 administration. ACT with tumor-infiltrating T lymphocytes demonstrates objective clinical responses in 50-72% of the patients, including 10-40% complete responses and was shown to produce durable disease control with long progression-free survival. Tumor-infiltrating T-lymphocyte ACT might even have curative potential as the vast majority of the complete responders are without any evidence of disease many years after treatment. Other adoptive transfer studies employ the genetic modification of T lymphocytes with genes encoding tumor-specific T cell receptors or antibody-based chimeric antigen receptors. These approaches opened numerous possibilities to treat cancers other than melanoma. In this article we will summarize the ACT strategies in melanoma, the new developments in this field and combinations with other therapies.

The presence of programmed death 1 (PD-1)-positive tumor-infiltrating lymphocytes is associated with poor prognosis in human breast cancer

Programmed death 1 (PD-1) is a co-inhibitory receptor in the CD28/CTL-4 family, and functions as a negative regulator of the immune system. Tumor-infiltrating lymphocytes (TIL) in many epithelial cancers express PD-1, suggesting that antitumor immunity may be modulated by the PD-1/PD-L1 signaling pathway, and promising results from two recent clinical trials with monoclonal antibodies targeting PD-1 or PD-L1 confirm the clinical relevance of this pathway in human cancer. To explore the role of PD-1(+) TIL in human breast cancer, we performed immunohistochemistry studies on a tissue microarray encompassing 660 breast cancer cases with detailed clinical annotation and outcomes data. PD-1(+) TIL were present in 104 (15.8 %) of the 660 breast cancer cases. Their presence was associated with tumor size, grade, and lymph node status, and was differentially associated with the intrinsic subtypes of breast cancer. In univariate survival analyses, the presence of PD-1(+) TIL was associated with a significantly worse overall survival (HR = 2.736, p < 0.001). In subset analyses, the presence of PD-1(+) TIL was associated with significantly worse overall survival in the luminal B HER2(-) subtype (HR = 2.678, p < 0.001), the luminal B HER2(+) subtype (HR = 3.689, p < 0.001), and the basal-like subtype (HR = 3.140, p < 0.001). This is the first study to demonstrate that the presence of PD-1(+) TIL is associated with poor prognosis in human breast cancer, with important implications for the potential application of antibody therapies targeting the PD-1/PD-L1 signaling pathway in this disease.

In vivo targeting of adoptively transferred T-cells with antibody- and cytokine-conjugated liposomes

In adoptive cell therapy (ACT), autologous tumor-specific T-cells isolated from cancer patients are activated and expanded ex vivo, then infused back into the individual to eliminate metastatic tumors. A major limitation of this promising approach is the rapid loss of ACT T-cell effector function in vivo due to the highly immunosuppressive environment in tumors. Protection of T-cells from immunosuppressive signals can be achieved by systemic administration of supporting adjuvant drugs such as interleukins, chemotherapy, and other immunomodulators, but these adjuvant treatments are often accompanied by serious toxicities and may still fail to optimally stimulate lymphocytes in all tumor and lymphoid compartments. Here we propose a novel strategy to repeatedly stimulate or track ACT T-cells, using cytokines or ACT-cell-specific antibodies as ligands to target PEGylated liposomes to transferred T-cells in vivo. Using F(ab')2 fragments against a unique cell surface antigen on ACT cells (Thy1.1) or an engineered interleukin-2 (IL-2) molecule on an Fc framework as targeting ligands, we demonstrate that >95% of ACT cells can be conjugated with liposomes following a single injection in vivo. Further, we show that IL-2-conjugated liposomes both target ACT cells and are capable of inducing repeated waves of ACT T-cell proliferation in tumor-bearing mice. These results demonstrate the feasibility of repeated functional targeting of T-cells in vivo, which will enable delivery of imaging contrast agents, immunomodulators, or chemotherapy agents in adoptive cell therapy regimens.

Targeting of the tumor necrosis factor receptor superfamily for cancer immunotherapy

The tumor necrosis factor (TNF) ligand and cognate TNF receptor superfamilies constitute an important regulatory axis that is pivotal for immune homeostasis and correct execution of immune responses. TNF ligands and receptors are involved in diverse biological processes ranging from the selective induction of cell death in potentially dangerous and superfluous cells to providing costimulatory signals that help mount an effective immune response. This diverse and important regulatory role in immunity has sparked great interest in the development of TNFL/TNFR-targeted cancer immunotherapeutics. In this review, I will discuss the biology of the most prominent proapoptotic and co-stimulatory TNF ligands and review their current status in cancer immunotherapy.

Tivozanib in the treatment of renal cell carcinoma

Renal cell carcinoma (RCC) is an aggressive malignancy compared to other urological malignancies and has been associated with poor responses to conventional cytotoxic chemotherapy. Interferon-α and interleukin-2 were previously utilized in a limited number of patients with good performance status due to toxicity and safety issues. Over the last decade, through advances in the understanding of the biology and pathology of RCC, the important role of vascular endothelial growth factor (VEGF) in RCC has been identified. Data from randomized trials have led to the approval of first-generation tyrosine kinase inhibitors (TKIs) sorafenib, sunitinib, and pazopanib; however, these agents inhibit a wide variety of kinase targets and are associated with a range of adverse effects. More recently, a new generation TKI, axitinib, has been approved by the US Food and Drug Administration. Tivozanib is a novel TKI, which is a potent inhibitor of VEGF-1, VEGF-2, VEGF-3, c-kit, and PDGR kinases, with a more restricted target spectrum. Phase II and III studies have demonstrated significant activity and a favorable safety profile as an initial targeted treatment for advanced RCC. This review examines the emerging data with tivozanib for the treatment of advanced RCC. Preclinical investigations as well as Phase I, II, and III data are examined; data on the comparative benefits of tivozanib are reviewed. Finally, we discuss the future potential of tivozanib in combination, biomarkers associated with tivozanib response, and acquisition of resistance and nonkidney cancer indications.

SOX2-specific adaptive immunity and response to immunotherapy in non-small cell lung cancer

Immunotherapeutic strategies including the blockade of programmed death 1 (PD-1) receptors hold promise for the treatment of various cancers including non-small cell lung carcinoma (NSCLC). Preclinical data suggest that pre-existing tumor immunity is important for disease regression upon checkpoint blockade-based therapies. However, the nature of antigen-specific T-cell responses that correlate with the clinical response to immunotherapy in NSCLC patients is not known. The embryonic stem cell gene SRY (sex determining region Y)-box 2 (SOX2) has recently emerged as a major oncogenic driver in NSCLC. Here, we show that nearly 50% of a cohort of NSCLC patients mounted both CD4⁺ and CD8⁺ T-cell responses against SOX2, which could be readily detected among peripheral blood mononuclear cells. T-cell responses against SOX2 were associated with NSCLC regression upon immunotherapy with anti-PD-1 monoclonal antibodies, whereas none of the patients lacking SOX2-specific T cells experienced disease regression following immune checkpoint blockade. Conversely, cellular and humoral responses against viral antigens or another tumor-associated antigen (NY-ESO-1) failed to correlate with the clinical response of NSCLC patients to immunotherapy. Of note, the administration of PD-1-blocking antibodies was associated with intramolecular epitope spread as well as with the amplification of SOX2-specific immune responses in vivo. These findings identify SOX2 as an important tumor-associated antigen in NSCLC and link the presence of SOX2-specific T cells with the clinical response of lung cancer patients to immunotherapy.

The role of the e3 ligase cbl-B in murine dendritic cells

Dendritic cells (DCs) are potent antigen-presenting cells with a promising potential in cancer immunotherapy. Cbl proteins are E3 ubiquitin ligases and have been implicated in regulating the functional activity of various immune cells. As an example, c-Cbl negatively affects DC activation. We here describe that another member of the Cbl-protein family (i.e. Cbl-b) is highly expressed in murine bone-marrow-derived DCs (BMDCs). Differentiation of cblb−/− bone marrow mononuclear cells into classical BMDCs is unaltered, except enhanced induction of DEC-205 (CD205) expression. When tested in mixed-lymphocyte reaction (MLR), cblb−/− BMDCs exhibit increased allo-stimulatory capacity in vitro. BMDCs were next in vitro stimulated by various toll like receptor (TLR)-agonists (LPS, Poly(I:C), CpG) and exposed to FITC-labeled dextran. Upon TLR-stimulation, cblb−/− BMDCs produce higher levels of proinflammatory cytokines (IL-1α, IL-6 and TNF-α) and exhibit a slightly higher level of FITC-dextran uptake. To further characterize the functional significance of cblb−/− BMDCs we tested them in antigen-specific T cell responses against ovalbumin (OVA) protein and peptides, activating either CD8⁺ OT-I or CD4⁺ OT-II transgenic T cells. However, cblb−/− BMDCs are equally effective in inducing antigen-specific T cell responses when compared to wildtype BMDCs both in vitro and in vivo. The migratory capacity into lymph nodes during inflammation was similarly not affected by the absence of Cbl-b. In line with these observations, cblb−/− peptide-pulsed BMDCs are equally effective vaccines against OVA-expressing B16 tumors in vivo when compared to wildtype BMDCs. We conclude that in contrast to c-Cbl, Cbl-b plays only a limited role in the induction of Ag-specific T cell responses by murine BMDCs in vitro and in vivo.

Developing a common language for tumor response to immunotherapy: immune-related response criteria using unidimensional measurements

PURPOSE

Immune-related response criteria (irRC) was developed to adequately assess tumor response to immunotherapy. The irRC are based on bidimensional measurements, as opposed to unidimensional measurements defined by Response Evaluation Criteria in Solid Tumors, which has been widely used in solid tumors. We aimed to compare response assessment by bidimensional versus unidimensional irRC in patients with advanced melanoma treated with ipilimumab.

EXPERIMENTAL DESIGN

Fifty-seven patients with advanced melanoma treated with ipilimumab in a phase II, expanded access trial were studied. Bidimensional tumor measurement records prospectively conducted during the trial were reviewed to generate a second set of measurements using unidimensional, longest diameter measurements. The percent changes of measurements at follow-up, best overall response, and time-to-progression (TTP) were compared between bidimensional and unidimensional irRC. Interobserver variability for bidimensional and unidimensional measurements was assessed in 25 randomly selected patients.

RESULTS

The percent changes at follow-up scans were highly concordant between the 2 criteria (Spearman r: 0.953-0.965, first to fourth follow-up). The best immune-related response was highly concordant between the 2 criteria (κw = 0.881). TTP was similar between the bidimensional and unidimensional assessments (progression-free at 6 months: 70% vs. 81%, respectively). The unidimensional measurements were more reproducible than bidimensional measurements, with the 95% limits of agreement of (-16.1%, 5.8%) versus (-31.3%, 19.7%), respectively.

CONCLUSION

irRC using the unidimensional measurements provided highly concordant response assessment compared with the bidimensional irRC, with less measurement variability. The use of unidimensional irRC is proposed to assess response to immunotherapy in solid tumors, given its simplicity, higher reproducibility, and high concordance with the bidimensional irRC.

Tumor-infiltrating PD1-Positive Lymphocytes and FoxP3-Positive Regulatory T Cells Predict Distant Metastatic Relapse and Survival of Clear Cell Renal Cell Carcinoma

BACKGROUND

Clear cell renal cell carcinoma (CRCC) is the most common malignant tumor of the kidney, and the clinical outcome of CRCC is related with the metastatic potential of CRCC. A significant proportion of metastatic CRCC remains incurable. Recently, immunotherapy against specific targets such as programmed death 1 (PD1) has been adapted for fatal cases of CRCC.

MATERIALS AND METHODS

In this study, we aimed to evaluate the potential of tumor-infiltrating PD1-positive lymphocytes or FoxP3-positive regulatory T cells (Tregs) as predictors of the metastatic potential or prognosis of CRCC and investigate possible correlations with Epstein-Barr virus (EBV) infection in 199 cases of CRCC.

RESULTS

PD1 positivity, high Treg number, and EBV infection all predicted poor overall survival (OS) by univariate analysis. PD1 positivity and high Treg numbers were also significantly correlated with more distant metastatic relapse (DMR) and poor relapse-free survival (RFS) by univariate analysis. PD1 positivity and high Treg number were independent prognostic indicators for OS. In addition, PD1 positivity was an independent predictor of RFS and DMR. EBV infection was an independent predictor of OS of CRCC.

CONCLUSION

This study demonstrates that intratumoral infiltration of PD1-positive or FoxP3-positive lymphocytes can be used as significant prognostic indicators of CRCC and PD1 positivity could be very helpful in the prediction of latent distant metastasis of CRCCs. Therefore, evaluation of the infiltration of PD-positive cells or Tregs in CRCC may be useful diagnostic tools for the selection of patients who could benefit from PD1- or Treg-based immunotherapy.

Optimal management of metastatic melanoma: current strategies and future directions

Melanoma is increasing in incidence and remains a major public health threat. Although the disease may be curable when identified early, advanced melanoma is characterized by widespread metastatic disease and a median survival of less than 10 months. In recent years, however, major advances in our understanding of the molecular nature of melanoma and the interaction of melanoma cells with the immune system have resulted in several new therapeutic strategies that are showing significant clinical benefit. Current therapeutic approaches include surgical resection of metastatic disease, chemotherapy, immunotherapy, and targeted therapy. Dacarbazine, interleukin-2, ipilimumab, and vemurafenib are now approved for the treatment of advanced melanoma. In addition, new combination chemotherapy regimens, monoclonal antibodies blocking the programmed death-1 (PD-1)/PD-ligand 1 pathway, and targeted therapy against CKIT, mitogen-activated protein/extracellular signal-regulated kinase (MEK), and other putative signaling pathways in melanoma are beginning to show promise in early-phase clinical trials. Further research on these modalities alone and in combination will likely be the focus of future clinical investigation and may impact the outcomes for patients with advanced melanoma.

Endogenous tumor-reactive CD8+ T cells are differentiated effector cells expressing high levels of CD11a and PD-1 but are unable to control tumor growth

Immunotherapies aimed at enhancing natural or endogenous antitumor T-cell immunity in patients affected by advanced malignancies are currently being implemented in the clinic with promising results. In order to optimize therapeutic protocols and monitor the effectiveness of such therapies, reliable biomarkers are needed. We used CD11a, an integrin that is upregulated on the surface of effector and memory CD8+ T cells, and PD-1, an immunoregulatory receptor expressed by activated T cells, as biomarkers to identify, quantify and monitor endogenous tumor-reactive cytotoxic T lymphocytes (CTLs) in two mouse tumor models and in the peripheral blood of 12 patients affected by Stage IV melanoma. High expression levels of CD11a and PD-1 were detected among CD8+ T cells residing within primary and metastatic murine tumor sites, as well as in spontaneous murine breast cancer tissues. In the peripheral blood of melanoma patients, tumor antigen-specific CD8+ T cells were associated with a population of CD11ahigh CD8+ T cells that co-expressed high levels of PD-1. Healthy donors exhibited a comparatively much lower frequency of such PD-1+CD11ahighCD8+ T cells. Phenotypic analyses demonstrated that CD11ahighCD8+ T cells are proliferating (Ki67+) and activated (CD62L-CD69+). Increased CD11ahighCD8+ T cells and delayed tumor growth were observed in PD-1 deficient mice, suggesting that the antitumor effector functions of CD8+ T cells is compromised by an elevated expression of PD-1. The CD11ahighCD8+ T-cell population expresses high levels of PD-1 and presumably constitutes the cellular target of PD-1 blockade therapy. The expression level of CD11a and PD-1 by CD8+ T cells may therefore represent a novel biomarker to identify and monitor endogenous tumor-reactive CTLs. This may not only provide an immunological readout for evaluating the efficacy of immunotherapy but also contribute to the selection of cancer patients who are likely to benefit from anti-PD-1 therapy.

Update on the targeted therapy of melanoma

Melanoma is the most aggressive of the cutaneous malignancies, causing more than 9,000 deaths in the past year in the United States. Historically, systemic therapies have been largely ineffective, because melanoma is usually resistant to cytotoxic chemotherapy. However, during the past few years, several targeted therapies have proved effective in this challenging disease. These recent advances have been facilitated by an improved understanding of the driving genetic aberrations of melanoma, particularly mutations in the mitogen-activated protein kinase (MAPK) pathway. Vemurafenib, a BRAF inhibitor, demonstrated an overall survival advantage in phase III trials and is an appropriate option for first-line therapy in metastatic BRAF mutant melanoma. Dabrafenib, another BRAF inhibitor, and trametinib, a MEK inhibitor, also have been shown to be effective in phase III trials for BRAF mutant melanoma and may be additional treatment options as monotherapy or in combination pending regulatory approval. Additionally, imatinib is a promising targeted therapy for patients whose tumors harbor a KIT mutation in exons 11 and 13. Although these targeted agents cause objective responses and clinical benefit in patients with metastatic melanoma, resistance invariably develops. New targets and strategies to overcome acquired resistance are urgently needed. Furthermore, no effective targeted therapy has been developed for NRAS mutant tumors or in melanomas with as yet unknown driver mutations. In this review, we discuss current molecular targeted treatment options and promising ongoing research to develop new strategies to treat melanoma.

Emerging and mechanism-based therapies for recurrent or metastatic Merkel cell carcinoma

Merkel cell carcinoma (MCC) is a rare but aggressive neuroendocrine skin cancer with a disease-specific mortality of approximately 40 %. The association of MCC with a recently discovered polyomavirus, combined with the increased incidence and mortality of MCC among immunocompromised patients, highlight the importance of the immune system in controlling this cancer. Initial management of MCC is summarized within the NCCN guidelines and in recently published reviews. The high rate of recurrent and metastatic disease progression in MCC, however, presents a major challenge in a cancer that lacks mechanism-based, disease-specific therapies. Traditional treatment approaches have focused on cytotoxic chemotherapy that, despite frequent initial efficacy, rarely provides durable responses and has high morbidity among the elderly. In addition, the immunosuppressive nature of chemotherapy is of concern when treating a virus-associated cancer for which survival is unusually tightly linked to immune function. With a median survival of 9.6 months after development of an initial metastasis (n = 179, described herein), and no FDA-approved agents for this cancer, there is an urgent need for more effective treatments. We review diverse management options for patients with advanced MCC, with a focus on emerging and mechanism-based therapies, some of which specifically target persistently expressed viral antigens. These treatments include single-dose radiation and novel immunotherapies, some of which are in clinical trials. Due to their encouraging efficacy, low toxicity, and lack of immune suppression, these therapies may offer viable alternatives to traditional cytotoxic chemotherapy.

Novel recombinant human b7-h4 antibodies overcome tumoral immune escape to potentiate T-cell antitumor responses

B7-H4 (VTCN1, B7x, B7s) is a ligand for inhibitory coreceptors on T cells implicated in antigenic tolerization. B7-H4 is expressed by tumor cells and tumor-associated macrophages (TAM), but its potential contributions to tumoral immune escape and therapeutic targeting have been less studied. To interrogate B7-H4 expression on tumor cells, we analyzed fresh primary ovarian cancer cells collected from patient ascites and solid tumors, and established cell lines before and after in vivo passaging. B7-H4 expression was detected on the surface of all fresh primary human tumors and tumor xenotransplants, but not on most established cell lines, and B7-H4 was lost rapidly by tumor xenograft cells after short-term in vitro culture. These results indicated an in vivo requirement for B7-H4 induction and defined conditions for targeting studies. To generate anti-B7-H4-targeting reagents, we isolated antibodies by differential cell screening of a yeast-display single-chain fragments variable (scFv) library derived from patients with ovarian cancer. We identified anti-B7-H4 scFv that reversed in vitro inhibition of CD3-stimulated T cells by B7-H4 protein. Notably, these reagents rescued tumor antigen-specific T-cell activation, which was otherwise inhibited by coculture with antigen-loaded B7-H4+ APCs, B7-H4+ tumor cells, or B7-H4- tumor cells mixed with B7-H4+ TAMs; peritoneal administration of anti-B7-H4 scFv delayed the growth of established tumors. Together, our findings showed that cell surface expression of B7-H4 occurs only in tumors in vivo and that antibody binding of B7-H4 could restore antitumor T-cell responses. We suggest that blocking of B7-H4/B7-H4 ligand interactions may represent a feasible therapeutic strategy for ovarian cancer.

Advances in the management of melanoma: targeted therapy, immunotherapy and future directions

Metastatic melanoma is an aggressive, immunogenic and molecularly heterogeneous disease for which most patients require systemic treatment. Recently, significant clinical breakthroughs have revolutionized the treatment of advanced melanoma, leading to the licensing of ipilimumab, a monoclonal antibody targeting cytotoxic T-lymphocyte-associated antigen 4, and vemurafenib, a BRAF inhibitor used in patients whose tumors contain a V600 mutation in the BRAF gene. This recent success has led to optimism and momentum has gathered with updated trial results from these therapies, next-generation compounds that target validated molecular pathways and novel agents that are mechanistically distinct. This review summarizes the recent advances and updated results since the licensing of vemurafenib and ipilimumab, the benefits and limitations of these agents, future strategies to improve upon existing treatments and overcome acquired resistance, in-progress and future clinical trials, as well as novel therapeutic targets, pathways and therapies that hold promise in advancing clinical benefit.

HHLA2 is a member of the B7 family and inhibits human CD4 and CD8 T-cell function

T-cell costimulation and coinhibition generated by engagement of the B7 family and their receptor CD28 family are of central importance in regulating the T-cell response, making these pathways very attractive therapeutic targets. Here we describe HERV-H LTR-associating protein 2 (HHLA2) as a member of the B7 family that shares 10-18% amino acid identity and 23-33% similarity to other human B7 proteins and phylogenetically forms a subfamily with B7x and B7-H3 within the family. HHLA2 is expressed in humans but not in mice, which is unique within the B7 and CD28 families. HHLA2 protein is constitutively expressed on the surface of human monocytes and is induced on B cells after stimulation with LPS and IFN-γ. HHLA2 does not interact with other known members of the CD28 family or the B7 family, but does bind a putative receptor that is constitutively expressed not only on resting and activated CD4 and CD8 T cells but also on antigen-presenting cells. HHLA2 inhibits proliferation of both CD4 and CD8 T cells in the presence of T-cell receptor signaling. In addition, HHLA2 significantly reduces cytokine production by T cells including IFN-γ, TNF-α, IL-5, IL-10, IL-13, IL-17A, and IL-22. Thus, we have identified a unique B7 pathway that is able to inhibit human CD4 and CD8 T-cell proliferation and cytokine production. This unique human T-cell coinhibitory pathway may afford unique strategies for the treatment of human cancers, autoimmune disorders, infection, and transplant rejection and may help to design better vaccines.

Improvement of cancer immunotherapy by combining molecular targeted therapy

In human cancer cells, a constitutive activation of MAPK, STAT3, β-catenin, and various other signaling pathways triggers multiple immunosuppressive cascades. These cascades result in the production of immunosuppressive molecules (e.g., TGF-β, IL-10, IL-6, VEGF, and CCL2) and induction of immunosuppressive immune cells (e.g., regulatory T cells, tolerogenic dendritic cells, and myeloid-derived suppressor cells). Consequently, immunosuppressive conditions are formed in tumor-associated microenvironments, including the tumor and sentinel lymph nodes. Some of these cancer-derived cytokines and chemokines impair immune cells and render them immunosuppressive via the activation of signaling molecules, such as STAT3, in the immune cells. Thus, administration of signal inhibitors may inhibit the multiple immunosuppressive cascades by acting simultaneously on both cancer and immune cells at the key regulatory points in the cancer-immune network. Since common signaling pathways are involved in manifestation of several hallmarks of cancer, including cancer cell proliferation/survival, invasion/metastasis, and immunosuppression, targeting these shared signaling pathways in combination with immunotherapy may be a promising strategy for cancer treatment.

Immune modulation by genetic modification of dendritic cells with lentiviral vectors

Our work over the past eight years has focused on the use of HIV-1 lentiviral vectors (lentivectors) for the genetic modification of dendritic cells (DCs) to control their functions in immune modulation. DCs are key professional antigen presenting cells which regulate the activity of most effector immune cells, including T, B and NK cells. Their genetic modification provides the means for the development of targeted therapies towards cancer and autoimmune disease. We have been modulating with lentivectors the activity of intracellular signalling pathways and co-stimulation during antigen presentation to T cells, to fine-tune the type and strength of the immune response. In the course of our research, we have found unexpected results such as the surprising immunosuppressive role of anti-viral signalling pathways, and the close link between negative co-stimulation in the immunological synapse and T cell receptor trafficking. Here we review our major findings and put them into context with other published work.

Immunotherapy and immune evasion in prostate cancer

Metastatic prostate cancer remains to this day a terminal disease. Prostatectomy and radiotherapy are effective for organ-confined diseases, but treatment for locally advanced and metastatic cancer remains challenging. Although advanced prostate cancers treated with androgen deprivation therapy achieves debulking of disease, responses are transient with subsequent development of castration-resistant and metastatic disease. Since prostate cancer is typically a slowly progressing disease, use of immune-based therapies offers an advantage to target advanced tumors and to induce antitumor immunity. This review will discuss the clinical merits of various vaccines and immunotherapies in castrate resistant prostate cancer and challenges to this evolving field of immune-based therapies.

Pharmacotherapy of metastatic melanoma: emerging trends and opportunities for a cure

Metastatic melanoma is one of the most deadly forms of cancer and is poorly responsive to standard chemotherapeutics, such as Dacarbazine and Paclitaxel. Recently, the advent of Vemurafenib and Ipilimumab has broadened the spectrum of therapeutic options for advanced melanoma patients but the occurrence of resistance and of high-grade toxicities call for better and more effective treatments. This review focuses on approved and experimental therapies for metastatic melanoma. The mechanism of action and the reported efficacy data for small molecule drugs and biologics are discussed, outlining directions for future pharmaceutical research in this field.

A randomized, double-blind, placebo-controlled assessment of BMS-936558, a fully human monoclonal antibody to programmed death-1 (PD-1), in patients with chronic hepatitis C virus infection

Expression of the programmed death 1 (PD-1) receptor and its ligands are implicated in the T cell exhaustion phenotype which contributes to the persistence of several chronic viral infections, including human hepatitis C virus (HCV). The antiviral potential of BMS-936558 (MDX-1106) – a fully human anti-PD-1 monoclonal immunoglobulin-G4 that blocks ligand binding – was explored in a proof-of-concept, placebo-controlled single-ascending-dose study in patients (N = 54) with chronic HCV infection. Interferon-alfa treatment-experienced patients (n = 42) were randomized 5∶1 to receive a single infusion of BMS-936558 (0.03, 0.1, 0.3, 1.0, 3.0 mg/kg [n = 5 each] or 10 mg/kg [n = 10]) or of placebo (n = 7). An additional 12 HCV treatment-naïve patients were randomized to receive 10 mg/kg BMS-936558 (n = 10) or placebo (n = 2). Patients were followed for 85 days post-dose. Five patients who received BMS-936558 (0.1 [n = 1] or 10 mg/kg) and one placebo patient achieved the primary study endpoint of a reduction in HCV RNA ≥0.5 log₁₀ IU/mL on at least 2 consecutive visits; 3 (10 mg/kg) achieved a >4 log₁₀ reduction. Two patients (10 mg/kg) achieved HCV RNA below the lower limit of quantitation (25 IU/mL), one of whom (a prior null-responder) remained RNA-undetectable 1 year post-study. Transient reductions in CD4⁺, CD8⁺ and CD19⁺ cells, including both naïve and memory CD4⁺ and CD8⁺ subsets, were observed at Day 2 without evidence of immune deficit. No clinically relevant changes in immunoglobulin subsets or treatment-related trends in circulating cytokines were noted. BMS-936558 exhibited dose-related exposure increases, with a half-life of 20–24 days. BMS-936558 was mostly well tolerated. One patient (10 mg/kg) experienced an asymptomatic grade 4 ALT elevation coincident with the onset of a 4-log viral load reduction. Six patients exhibited immune-related adverse events of mild-to-moderate intensity, including two cases of hyperthyroidism consistent with autoimmune thyroiditis. Further investigation of PD-1 pathway blockade in chronic viral disease is warranted.

Trial Registration

ClinicalTrials.gov NCT00703469 NCT00703469

What are the molecules involved in regulatory T-cells induction by dendritic cells in cancer?

Dendritic cells (DCs) are essential for the maintenance of homeostasis in the organism, and they do that by modulating lymphocyte priming, expansion, and response patterns according to signals they receive from the environment. The induction of suppressive lymphocytes by DCs is essential to hinder the development of autoimmune diseases but can be reverted against homeostasis when in the context of neoplasia. In this setting, the induction of suppressive or regulatory T cells contributes to the establishment of a state of tolerance towards the tumor, allowing it to grow unchecked by an otherwise functional immune system. Besides affecting its local environment, tumor also has been described as potent sources of anti-inflammatory/suppressive factors, which may act systemically, generating defects in the differentiation and maturation of immune cells, far beyond the immediate vicinity of the tumor mass. Cytokines, as IL-10 and TGF-beta, as well as cell surface molecules like PD-L1 and ICOS seem to be significantly involved in the redirection of DCs towards tolerance induction, and recent data suggest that tumor cells may, indeed, modulate distinct DCs subpopulations through the involvement of these molecules. It is to be expected that the identification of such molecules should provide molecular targets for more effective immunotherapeutic approaches to cancer.

Exposing a deadly alliance: novel insights into the biological links between COPD and lung cancer

Chronic obstructive pulmonary disease (COPD) affects more than 200 million people worldwide and is expected to become the third leading cause of death in 2020. COPD is characterized by progressive airflow limitation, due to a combination of chronic inflammation and remodeling of the small airways (bronchiolitis) and loss of elastic recoil caused by destruction of the alveolar walls (emphysema). Lung cancer is the most important cause of cancer-related death in the world. (Cigarette) smoking is the principal culprit causing both COPD and lung cancer; in addition, exposure to environmental tobacco smoke, biomass fuel smoke, coal smoke and outdoor air pollution have also been associated with an increased incidence of both diseases. Importantly, smokers with COPD--defined as either not fully reversible airflow limitation or emphysema--have a two- to four-fold increased risk to develop lung cancer. In this review, we highlight several of the genetic, epigenetic and inflammatory mechanisms, which link COPD and carcinogenesis in the lungs. Elucidating the biological pathways and networks, which underlie the increased susceptibility of lung cancer in patients with COPD, has important implications for screening, prevention, diagnosis and treatment of these two devastating pulmonary diseases.

Prospects of combinatorial synthetic peptide vaccine-based immunotherapy against cancer

The insight that the immune system is involved in tumor resistance is gaining momentum and this has led to the development of immunotherapeutic strategies aiming at enhancement of immune-mediated tumor destruction. Although some of these strategies have moderate clinical benefit, most stand-alone therapies fail to significantly affect progressive disease and survival or do so only in a minority of patients. Research on the mechanisms underlying the generation of immune responses against tumors and the immune evasion by tumors has emphasized that various mechanisms simultaneously prevent effective immunity against cancer including inefficient presentation of tumor antigens by dendritic cells and induction of negative immune regulation by regulatory T-cells (Tregs) and myeloid derived suppressor cells (MDSCs). Thus the design of therapies that simultaneously improve effective tumor immunity and counteract immune evasion by tumors seems most desirable for clinical efficacy. As it is unlikely that a single immunotherapeutic strategy addresses all necessary requirements, combinatorial strategies that act synergistically need to be developed. Here we discuss the current knowledge and prospects of treatment with synthetic peptide vaccines that stimulate tumor-specific T-cell responses combined with adjuvants, immune modulating antibodies, cytokines and chemotherapy. We conclude that combinatorial approaches have the best potency to accomplish the most significant tumor destruction but further research is required to optimize such approaches.

Current clinical immunotherapy targets in advanced nonsmall cell lung cancer (NSCLC)

NSCLC remains one of the most challenging malignancies to treat. Despite the introduction of innovative therapies over the last decade, the 5-year survival of NSCLC is still <20%. Clearly, novel, therapeutic approaches are required. Targeting the immune system to derive meaningful clinical benefit has proved successful in various malignancies in recent years. As a result, there is renewed focus on the use of immunotherapy in lung cancer. In this review, we provide an overview of current immune-modulatory approaches in the treatment of NSCLC.

Immune checkpoint blockade immunotherapy to activate anti-tumour T-cell immunity

The tumour microenvironment plays a dual role in cancer: it can promote tumour progression by establishing pro-tumour survival conditions but can also suppress tumour progression by killing cancer cells or inhibiting their outgrowth. These dynamically interconnected processes are under intense investigation to better understand cancer pathophysiology and allow identification of new therapeutic approaches. The ability of cancer cells to evade anti-tumour T-cell activity in the microenvironment has recently been accepted as a hallmark of cancer progression. This review will highlight the most promising therapeutic approach aimed at activating anti-tumour T-cell immunity in the cancer microenvironment: blocking inhibitory immune regulatory proteins (immune checkpoint ligands and receptors). There is emerging evidence that haematological tumours co-opt immune checkpoints as a major immune resistance mechanism. Pre-clinical findings indicate that targeted therapies and blockade of immune checkpoints could be combined to promote therapeutic synergy and long-term anti-tumour immunity to improve clinical outcomes for cancer patients.

Recent advances in the treatment of metastatic renal cell carcinoma

In the past 5 years, the treatment of patients with metastatic renal cell carcinoma has changed dramatically from being largely cytokine-based with the emergence of targeted therapy. Following the elucidation of various molecular pathways in renal cell carcinoma, targeted agents (particularly vascular endothelial growth factor-targeting antiangiogenic agents) now form the backbone of most therapeutic strategies for patients with metastatic renal cell carcinoma and the outcome of treatment has improved. However, many tumors eventually develop resistance to targeted therapy due to secondary mutation of the target protein or compensatory changes within the target pathway that bypass the site of inhibition. On the other hand, there are new forms of immunotherapy that hold the promise of improving the outcome for patients with metastatic renal cell carcinoma. In this article, we describe some of these new therapies, including the anti-vascular endothelial growth factor monoclonal antibody bevacizumab, several receptor tyrosine kinase inhibitors (sorafenib, sunitinib, pazopanib, axitinib, and tivozanib), the mammalian target of rapamycin inhibitors temsirolimus and everolimus, and new immunotherapy modalities, such as anti-cytotoxic T-lymphocyte-associated antigen 4 antibody and anti-programmed cell death 1/programmed cell death-ligand 1 antibody. We also discuss their role in the current management of patients with metastatic renal cell carcinoma.

Genomic Medicine Frontier in Human Solid Tumors: Prospects and Challenges

Recent discoveries of genomic alterations that underlie and promote the malignant phenotype, together with an expanded repertoire of targeted agents, have provided many opportunities to conduct hypothesis-driven clinical trials. The ability to profile each unique cancer for actionable aberrations by using high-throughput technologies in a cost-effective way provides unprecedented opportunities for using matched therapies in a selected patient population. The major challenges are to integrate and make biologic sense of the substantial genomic data derived from multiple platforms. We define two different approaches for the analysis, interpretation, and clinical applicability of genomic data: (1) the genomically stratified model originates from the “one test-one drug” paradigm and is currently being expanded with an upfront multicategorical approach following recent advances in multiplexed genotyping platforms; and (2) the comprehensive assessment model is based on whole-genome, -exome, and -transcriptome data and allows identification of novel drivers and subsequent therapies in the experimental setting. Tumor heterogeneity and evolution of the diverse populations of cancer cells during cancer progression, influenced by the effects of systemic treatments, will need to be addressed in the new scenario of early drug development. Logistical issues related to prescreening strategies and trial allocation, in addition to concerns in the economic and ethical domains, must be taken into consideration. Here we present a historical view of how increased understanding of cancer genomics has been translated to the clinic and discuss the prospects and challenges for further implementation of a personalized treatment strategy for human solid tumors.

Immunological insights from patients undergoing surgery on ipilimumab for metastatic melanoma

BACKGROUND

The tumor microenvironment after treatment with ipilimumab is not well described. Furthermore, the safety of surgery for patients being treated with ipilimumab for metastatic melanoma has not been well reported. This study analyzed the safety of surgery and the immune phenotype of tumors resected while on ipilimumab.

METHODS

From our prospective melanoma database, we identified patients undergoing surgery for any indication within 30 days of receiving a dose of induction ipilimumab or while on maintenance ipilimumab therapy. Surgical toxicity was graded 1-5 by the Clavien classification. Tumor-infiltrating lymphocytes were classified by flow cytometry and compared with peripheral blood.

RESULTS

23 patients were identified who underwent 34 operations a median of 27 weeks after initiation of ipilimumab (1-123 weeks). Subcutaneous resections were the most frequent, followed by intra-abdominal and nodal procedures. Grade 1 or 2 wound complications were seen in 22% of patients. No Grade 3-5 complications were seen. Analysis of the T cell infiltrate and matched peripheral blood from ten patients showed an elevated % of CD4+FOXP3+ T-regulatory cells and a 2.8-fold lower ratio of CD8+/CD4+FOXP3+ in the tumor compared with blood (p=0.02). In addition, all CD8+ T cells had a higher expression of PD-1 in the tumor, compared with peripheral blood.

CONCLUSIONS

Surgery for patients on ipilimumab is safe. This study highlights the immunosuppressive phenotype in tumors not responding to immunotherapy. The high percentage of T-regulatory cells and low T-effector cells in progressive tumors suggests a possible mechanism of immune escape.

PD-L1 blockade synergizes with IL-2 therapy in reinvigorating exhausted T cells

The inhibitory receptor programmed cell death 1 (PD-1) plays a major role in functional exhaustion of T cells during chronic infections and cancer, and recent clinical data suggest that blockade of the PD-1 pathway is an effective immunotherapy in treating certain cancers. Thus, it is important to define combinatorial approaches that increase the efficacy of PD-1 blockade. To address this issue, we examined the effect of IL-2 and PD-1 ligand 1 (PD-L1) blockade in the mouse model of chronic lymphocytic choriomeningitis virus (LCMV) infection. We found that low-dose IL-2 administration alone enhanced CD8+ T cell responses in chronically infected mice. IL-2 treatment also decreased inhibitory receptor levels on virus-specific CD8+ T cells and increased expression of CD127 and CD44, resulting in a phenotype resembling that of memory T cells. Surprisingly, IL-2 therapy had only a minimal effect on reducing viral load. However, combining IL-2 treatment with blockade of the PD-1 inhibitory pathway had striking synergistic effects in enhancing virus-specific CD8+ T cell responses and decreasing viral load. Interestingly, this reduction in viral load occurred despite increased numbers of Tregs. These results suggest that combined IL-2 therapy and PD-L1 blockade merits consideration as a regimen for treating human chronic infections and cancer.

T cell immunotherapy for melanoma from bedside to bench to barn and back: how conceptual advances in experimental mouse models can be translated into clinical benefit for patients

A solid scientific basis now supports the concept that cytotoxic T lymphocytes can specifically recognize and destroy melanoma cells. Over the last decades, clinicians and basic scientists have joined forces to advance our concepts of melanoma immunobiology. This has catalyzed the rational development of therapeutic approaches to enforce melanoma-specific T cell responses. Preclinical studies in experimental mouse models paved the way for their successful translation into clinical benefit for patients with metastatic melanoma. A more thorough understanding of how melanomas develop resistance to T cell immunotherapy is necessary to extend this success. This requires a continued interdisciplinary effort of melanoma biologists and immunologists that closely connects clinical observations with in vitro investigations and appropriate in vivo mouse models: From bedside to bench to barn and back.

PD-L1 expression is characteristic of a subset of aggressive B-cell lymphomas and virus-associated malignancies

PURPOSE

Programmed cell death ligand 1 (PD-L1) is an immunomodulatory molecule expressed by antigen-presenting cells and select tumors that engages receptors on T cells to inhibit T-cell immunity. Immunotherapies targeting the PD-1/PD-L1 pathway have shown durable antitumor effects in a subset of patients with solid tumors. PD-L1 can be expressed by Reed-Sternberg cells comprising classical Hodgkin lymphoma (CHL) and by malignant B cells comprising EBV-positive posttransplant lymphoproliferative disorders (PTLD). We sought to determine whether the expression of PD-L1 represents a general strategy of immune evasion among aggressive B-cell lymphomas and virus- and immunodeficiency-associated tumors.

EXPERIMENTAL DESIGN

Using novel antibodies and formalin-fixed, paraffin-embedded (FFPE) tissue biopsies, we examined 237 primary tumors for expression of PD-L1.

RESULTS

Robust PD-L1 protein expression was found in the majority of nodular sclerosis and mixed cellularity CHL, primary mediastinal large B-cell lymphoma, T-cell/histiocyte-rich B-cell lymphoma, EBV-positive and -negative PTLD, and EBV-associated diffuse large B-cell lymphoma (DLBCL), plasmablastic lymphoma, extranodal NK/T-cell lymphoma, nasopharyngeal carcinoma, and HHV8-associated primary effusion lymphoma. Within these tumors, PD-L1 was highly expressed by malignant cells and tumor-infiltrating macrophages. In contrast, neither the malignant nor the nonmalignant cells comprising nodular lymphocyte-predominant Hodgkin lymphoma, DLBCL-not otherwise specified, Burkitt lymphoma, and HHV8-associated Kaposi sarcoma expressed detectable PD-L1.

CONCLUSION

Certain aggressive B-cell lymphomas and virus- and immunodeficiency-associated malignancies associated with an ineffective T-cell immune response express PD-L1 on tumor cells and infiltrating macrophages. These results identify a group of neoplasms that should be considered for PD-1/PD-L1-directed therapies, and validate methods to detect PD-L1 in FFPE tissue biopsies.

Pegylated IL-10 induces cancer immunity: the surprising role of IL-10 as a potent inducer of IFN-γ-mediated CD8(+) T cell cytotoxicity

Recently, the development of several strategies based on immunotherapy has raised hopes for a more promising way to treat cancer patients. Here, we describe how interleukin (IL)-10, a seemingly unlikely candidate, stimulates the immune system in a particularly efficacious way. IL-10, an omnipotent anti-inflammatory cytokine, delivers an equally potent immune stimulation in the context of CD8(+) T cells and tumor immunity. By activation of tumor-resident, tumor-specific CD8(+) T cells, pegylated IL-10 can induce rejection of large and metastasizing tumors in mice. Here, we summarize the mechanisms of action of IL-10, the reasons why the mechanisms may be crucial for the treatment of cancer patients, and the rationale for applying pegylated IL-10 in the clinic.

Blockade of the negative co-stimulatory molecules PD-1 and CTLA-4 improves survival in primary and secondary fungal sepsis

Introduction

Fungal sepsis is an increasingly common problem in intensive care unit patients.Mortality from fungal sepsis remains high despite antimicrobial therapy that is highly active against most fungal pathogens, a finding consistent with defective host immunity that is present in many patients with disseminated fungemia.One recently recognized immunologic defect that occurs in patients with sepsis is T cell "exhaustion" due to increased expression of programmed cell death -1 (PD-1).This study tested the ability of anti-PD-1 and anti-programmed cell death ligand -1 (anti-PD-L1) antagonistic antibodies to improve survival and reverse sepsis-induced immunosuppression in two mouse models of fungal sepsis.

Methods

Fungal sepsis was induced in mice using two different models of infection, that is, primary fungal sepsis and secondary fungal sepsis occurring after sub-lethal cecal ligation and puncture (CLP).Anti-PD-1 and anti-PD-L1 were administered 24 to 48 h after fungal infection and effects on survival, interferon gamma production, and MHC II expression were examined.

Results

Anti-PD-1 and anti-PD-L1 antibodies were highly effective at improving survival in primary and secondary fungal sepsis.Both antibodies reversed sepsis-induced suppression of interferon gamma and increased expression of MHC II on antigen presenting cells.Blockade of cytotoxic T-lymphocyte antigen-4 (CTLA-4), a second negative co-stimulatory molecule that is up-regulated in sepsis and acts like PD-1 to suppress T cell function, also improved survival in fungal sepsis.

Conclusions

Immuno-adjuvant therapy with anti-PD-1, anti-PD-L1 and anti-CTLA-4 antibodies reverse sepsis-induced immunosuppression and improve survival in fungal sepsis.The present results are consistent with previous studies showing that blockade of PD-1 and CTLA-4 improves survival in bacterial sepsis.Thus, immuno-adjuvant therapy represents a novel approach to sepsis and may have broad applicability in the disorder.Given the relative safety of anti-PD-1 antibody in cancer clinical trials to date, therapy with anti-PD-1 in patients with life-threatening sepsis who have demonstrable immunosuppression should be strongly considered.

At the bedside: CTLA-4- and PD-1-blocking antibodies in cancer immunotherapy

It is increasingly appreciated that cancers are recognized by the immune system, and under some circumstances, the immune system may control or even eliminate tumors. The modulation of signaling via coinhibitory or costimulatory receptors expressed on T cells has proven to be a potent way to amplify antitumor immune responses. This approach has been exploited successfully for the generation of a new class of anticancer therapies, "checkpoint-blocking" antibodies, exemplified by the recently FDA-approved agent, ipilimumab, an antibody that blocks the coinhibitory receptor CTLA-4. Capitalizing on the success of ipilimumab, agents that target a second coinhibitory receptor, PD-1, or its ligand, PD-L1, are in clinical development. Lessons learned from treating patients with CTLA-4 and PD-1 pathway-blocking antibodies will be reviewed, with a focus on concepts likely to inform the clinical development and application of agents in earlier stages of development. See related review At the bench: Preclinical rationale for CTLA-4 and PD-1 blockade as cancer immunotherapy.

Tumour heterogeneity and immune-modulation

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Intratumour heterogeneity (ITH) has been demonstrated in various tumour types.

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Distinct clonal subpopulations can exist within different regions of a tumour.

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ITH has evident implications for cancer diagnosis and treatment.

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There is increasing evidence for the association between ITH and drug resistance.

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ITH may allow the effective use of immunotherapeutics against tumour neo-antigens.

Recent advances in sequencing technologies have revealed extensive intratumour heterogeneity (ITH) both within individual tumours and between primary and metastatic tumours for different cancer types. Such genetic diversity may have clinical implications for both cancer diagnosis and treatment with increasing evidence linking ITH and therapeutic resistance. Nonetheless, whilst limiting the activity of targeted agents, tumour genetic heterogeneity may provide a new therapeutic opportunity through generation of neo-antigens that could be recognised and targeted by the patient's own immune system in response to immune-modulatory therapies. Longitudinal genomic studies assessing tumour clonal architecture and its correlation with the underlying immune response to cancer in each particular patient are needed to follow tumour evolutionary dynamics over time and through therapy, in order to further understand the mechanisms behind drug resistance and to inform the development of new combinatorial therapeutic strategies.

Cellular immunotherapy for plasma cell myeloma

Allogeneic hematopoietic cell transplantation for plasma cell myeloma can lead to graft-vs-myeloma immunity and long-term survivorship, but limited efficacy and associated toxicities have prevented its widespread use. Cellular immunotherapies seek to induce more specific, reliable and potent antimyeloma immune responses with less treatment-related risk than is possible with allogeneic transplantation. Strategies under development include infusion of vaccine-primed and ex vivo expanded/costimulated autologous T cells after high-dose melphalan, genetic engineering of autologous T cells with receptors for myeloma-specific epitopes, administration of DC/plasma cell fusions and administration expanded marrow-infiltrating lymphocytes. In addition, novel immunomodulatory drugs such as inhibitors of the programmed death-1 T cell regulatory pathway may synergize with cellular immunotherapies.

Immunotherapeutic approaches in triple-negative breast cancer: latest research and clinical prospects

Triple-negative breast cancer (TNBC), as defined by the absence of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 expression, is a challenging disease with the poorest prognosis of all breast cancer subtypes. Importantly, there are currently no known molecular targets for this subgroup of patients. Recent advances in genomics and gene expression profiling have shed new light on the molecule heterogeneity of TNBC. We present an overview of the scientific evidence suggesting that clinical outcome in TNBC is affected by tumor-infiltrating immune cells. We also describe tumor-associated antigens recently identified in TNBC. Finally, we review the current literature on promising immunotherapies for TNBC, including tumor vaccine approaches, immune-checkpoint inhibitors, antagonists of immunosuppressive molecules and adoptive cell therapies. It is our contention that selected patients with TNBC with lymphocytic tumor infiltrates at diagnosis may benefit from immune-based therapies and that these immunotherapies will be most beneficial in combination with cytotoxic drugs that potentiate adaptive anti-tumor immunity.