Cancer Immunology Research Research Articles

Chimeric Antigen Receptor T Cells Targeting NKG2D-Ligands Show Robust Efficacy Against Acute Myeloid Leukemia and T-Cell Acute Lymphoblastic Leukemia

CAR T cell approaches to effectively target AML and T-ALL without off-tumor effects on healthy myeloid or T cell compartments respectively are an unmet medical need. NKG2D-ligands are a promising target given their absence on healthy cells and surface expression in a wide range of malignancies. NKG2D-ligand expression in T-ALL has not previously been interrogated, and reports regarding the prevalence and density of NKG2D-ligand expression in AML vary. A first-in-human clinical trial of CART cells targeting NKG2D ligands in patients with AML demonstrated safety and feasibility (Baumeister et al, Cancer Immunology Research 2019). However, at low CAR T cell doses without lymphodepletion clinical efficacy was limited and in this selective patient cohort, NKG2D-ligand expression was only detectable at low levels. To broadly assess the level of NKG2D-ligand expression in AML and T-ALL and evaluate how this correlates with leukemia susceptibility to CAR T cells targeting NKG2D-ligands, we employed NKG2D-fusion protein-based flow-cytometry and RNA sequencing. CAR T cells bearing the full-length native NKG2D-receptor coupled to the CD3ζ cytoplasmic domain were generated using γ-retroviral transduction and then evaluated in functional assays. We show that NKG2D-ligands are expressed in T-ALL cell lines and primary T-ALL and confirm that NKG2D-ligands are frequently expressed at the surface and RNA-level in primary AML, albeit at relatively low levels. We demonstrate that high-expressing AML and T-ALL targets are exquisitely susceptible to in vitro activity of CAR T cells targeting NKG2D-ligands as evidenced by CD107a degranulation, cytotoxicity and production of IFN-γ and TNF-α. Importantly, we show that even low-level ligand expression in primary leukemia targets results in robust NKG2D-CAR activity. Using mass-cytometry, we reveal a distinct phenotypic profile of NKG2D-CAR T cells following incubation with ligand-positive leukemia targets when compared to controls. This includes selective upregulation of ICOS, 41BB, PD-1, LAG-3 and OX40. Given clinical precedent of pharmacologic HDAC inhibition in AML, we next assessed the impact of preincubation with Valproic Acid (VPA) on NKG2D-ligand expression in AML and whether this enhances susceptibility to NKG2D-CART cells in functional assays. We demonstrate that NKG2D-ligand expression can be selectively enhanced in low-expressing AML cell lines and primary AML blasts when AML cells are pre-incubated with 1mM VPA for 24 hours. Such pharmacologic ligand induction significantly augments NKG2D-CAR anti-leukemic activity in functional assays without affecting healthy Peripheral Blood Mononuclear Cells or CAR T cells. Our findings demonstrate that NKG2D-ligands are viable targets for CAR T cell therapy in AML and T-ALL despite low-level cell-surface expression and provide the rationale for the combination of HDAC-inhibitors with NKG2D-CAR T cell therapy as a potential strategy to achieve clinical NKG2D-CAR T cell efficacy in AML. Figure: A) Specific fluorescence intensity of NKG2D-ligand surface expression in Cell lines and Primary Leukemia cells are displayed in comparison B) NKG2D-CAR T cells (CAR) degranulate and produce proinflammatory cytokines during co-culture with AML and T-ALL lines (representative flow plot, left panel), but not to negative controls, whereas T cells transduced with vector lacking the CAR-transgene (Empty) do not. C) NKG2D-CAR T cells but not Empty control T cells display striking killing activity against AML and T-ALL cell lines. D) Preincubation of primary AML blasts with 1mM VPA for 24 hours enhances NKG2D-ligand expression and significantly augments NKG2D-CAR T cell activity, shown here as IFN-γ production during co-culture with 3 independent primary AML samples. Figure Disclosures Dranoff: Novartis: Employment. Ritz:Equillium: Research Funding; Merck: Research Funding; Kite Pharma: Research Funding; Aleta Biotherapeutics: Consultancy; Celgene: Consultancy; Avrobio: Consultancy; LifeVault Bio: Consultancy; Draper Labs: Consultancy; Talaris Therapeutics: Consultancy; TScan Therapeutics: Consultancy.

Profile of pembrolizumab in the treatment of patients with unresectable or metastatic urothelial carcinoma.

The prognosis of patients with unresectable or metastatic urothelial carcinoma (UC) is poor. Platinum-based chemotherapy has been the standard first-line treatment in these patients for the past decade; however, the 5-year overall survival (OS) rate is only 13–22%. Recent advances in cancer immunology research have highlighted the pivotal role of the immune system in cancer development and progression, and new immune checkpoint inhibitors (ICIs) have demonstrated efficacy in a large variety of tumors including UC. Currently, five ICIs, including two anti-PD-1 antibodies (pembrolizumab and nivolumab) and three anti-PD-L1 antibodies (atezolizumab, avelumab, and durvalumab), have been granted approval by the US Food and Drug Administration (FDA) for patients with unresectable or metastatic UC who recurred or progressed after platinum-based chemotherapy. Among these agents, only pembrolizumab is supported by strong evidence from a large randomized Phase III trial (KEYNOTE-045). This trial demonstrated statistically significant improvements in OS for patients assigned to the pembrolizumab arm compared with the chemotherapy arm, both in the total population (HR 0.73; P=0.002) and in the population with high PD-L1 expression (HR 0.57; P=0.005). For patients with cisplatin-ineligible UC, pembrolizumab and atezolizumab were approved based on Phase II studies, with limitations on the use of these agents in patients with high tumor PD-L1 expression later imposed by the FDA. In conclusion, pembrolizumab may be a potential first-choice second-line therapy for unresectable or metastatic UC patients following platinum-based chemotherapy. Several Phase III trials are ongoing to evaluate the efficacy and toxicity of combination therapies of ICIs with chemotherapy, and ICIs with other ICIs with or without chemotherapy as first-line therapy. The results of these trials might redirect treatment strategies for patients with unresectable or metastatic UC.

A Robotic Microscope System to Examine T Cell Receptor Acuity Against Tumor Neoantigens: A New Tool for Cancer Immunotherapy Research

During immune surveillance, cytotoxic T lymphocytes (CTL) can selectively identify and destroy tumor cells by recognizing tumor-specific peptides (neoantigens), bound to major histocompatibility complex molecules (pMHC) arrayed on cancer cell surfaces. CTL use the same machinery to destroy virally infected cells displaying pathogen-specific pMHC, while leaving intact healthy cells expressing normal self-pMHC. We present a robotic microscope that allows scientists to conduct highly sensitive and selective T cell-pMHC studies with high throughput. Our system manipulates micro-meter beads coated with particular pMHC, presents them to T cells and generates piconewton-level intermolecular forces required to detect T cell acuity with a neoantigen. Our system integrates optical tweezers, precision nano-micro stages, and episcopic/diascopic illumination schemes at two magnifications. We create a coordinate referencing system to locate translucent T cells in three-dimensional, over a large space, based on the characteristic intensity change at each focal plane caused by the cells. Our system performs automated experiments to detect the level of T cell acuity with specific pMHCs, by measuring the downstream cellular responses. High acuity T cells can be selectively recovered for single cell analysis. Our new methodology and tool will have a significant impact on cancer immunotherapy and immunology research.

High co-expression of IL-34 and M-CSF correlates with tumor progression and poor survival in lung cancers

Despite recent advances in diagnosis and treatment of lung cancers, the 5-year survival rate remains unsatisfactory, which necessitates the identification of novel factors that associates with disease progression and malignant degree for improving diagnostic and therapeutic strategies. Recent progress in cancer immunology research has unveiled critical roles for colony stimulating factor 1 receptor (CSF1R) in multiple aspects of the tumor microenvironment. CSF1R is expressed on tumor-associated macrophages (TAMs), and mediates important pro-tumorigenic functions. CSF1R also provides critical autocrine signals that promote cancer cell survival and proliferation. Activation of CSF1R can be achieved by two independent ligands; macrophage colony-stimulating factor (M-CSF) and interleukin 34 (IL-34). Accordingly, the expression of these ligands in cancer is expected to result in poor prognosis. In this study, we show that IL-34 and M-CSF expression correlates with poor survival in a cohort of lung cancer patients. Importantly, high co-expression of IL-34 and M-CSF associates with the poorest survival compared to cancers that show weak or absent expression of the two ligands. Furthermore, high expression of IL-34 and M-CSF associates with advanced stages of lung cancers. Together, these results indicate a correlation between IL-34/M-CSF expression with poor survival and disease progression in lung cancer patients.

Abstract 605: Potency of Gp96-Ig/Fc-OX40L cell-based combination vaccine in cancer immunotherapy

Abstract The breakthrough discoveries of checkpoint inhibitors in the field of tumor immunology have driven the clinical success of immunotherapies for cancer, despite their beneficial efficacy in only a small portion of patients. This is due in part to immuno-evasive mechanisms and the inability of the immune system to recognize tumor antigens as foreign. As a therapeutic approach to effectively present these tumor antigens in order to elicit an anti-tumor immune response, we previously designed and characterized an allogenic, gp96-Ig secreting, cell-based vaccine (ImPACT); currently being assessed in a phase II study in non-muscle invasive bladder cancer and a phase Ib study in non-small cell lung cancer – the latter, in combination with the PD-1 antagonist Nivolumab. We recently characterized a ‘next-generation’ vaccine (ComPACT) that combines the tumor antigen chaperone Gp96-Ig along with the T cell costimulator Fc-OX40L, which are both secreted from the same cell (Fromm et. al. Cancer Immunology Research. 2016). In preclinical assays, ComPACT is effective at stimulating CD4+ and CD8+ antigen-specific T cell expansion, the programing of a durable memory T cell phenotype, and the elimination of melanoma and colon tumors. This anti-tumor efficacy is enhanced when ComPACT is combined with checkpoint inhibition (anti-PD1 or anti-PDL1). To support manufacturing and clinical efforts of both ImPACT and ComPACT, in anticipation of phase III expansion and/or new trial initiation, we have developed novel potency assays to quantify the biologically active form of Gp96-Ig and the in vitro activity of Fc-OX40L on T cell costimulation. It has been shown that gp96 can interact with toll-like receptors (TLR) and that this interaction results in the activation of the NF-κB pathway. Since THP1 cells express abundant TLR2/4, we engineered a THP1 cell line to express luciferase that is regulated by NF-κB response elements. Furthermore, we utilized the human T cell line; Jurkat, as host cells in which we also express NF-κB-luciferase, to quantify Fc-OX40L costimulation. Jurkat/NF-κB-luciferase cells primed with either CD3/CD28 or TNFα, and subsequently cultured with ComPACT-secreted Fc-OX40L, results in a dose dependent increase in NF-κB (luciferase) expression. Our current data in both assays shows a linear correlation with the input of Gp96-Ig and Fc-OX40L, and may serve as an effective potency assay to facilitate the manufacturing of our vaccine product as it transitions into more advanced cancer immunotherapy clinical studies. Citation Format: Xin Xu, Louise E. Gonzalez, George J. Fromm, Suresh de Silva, Louise Giffin, Jason Rose, Taylor H. Schreiber. Potency of Gp96-Ig/Fc-OX40L cell-based combination vaccine in cancer immunotherapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 605. doi:10.1158/1538-7445.AM2017-605

Rational Combination Immunotherapy: Understand the Biology.

Selecting rational treatment combinations remains a major challenge for improving immunotherapy outcomes. In this issue of Cancer Immunology Research, Zhang and colleagues reduced tumors by inhibiting CD47 in a lung carcinoma model, a treatment that inadvertently induced autophagy through inhibition of the Akt/mTOR pathway. By also targeting autophagy, the therapeutic response improved, highlighting the importance of understanding the biology beneath antitumor immunity. Cancer Immunol Res; 5(5); 355-6. ©2017 AACRSee article by Zhang et al., p. 363.

Lenalidomide with Ipilimumab for Lymphoid Malignancies after Allogeneic or Autologous Stem Cell Transplantation (SCT)

Background: Prevention or treatment of relapse after SCT for lymphoid malignancies requires novel strategies. Targeting immune checkpoints could result in lasting responses but only in few patients. Combination strategies with targeted agents, such as lenalidomide, could result in the release of tumor antigens to tumor-specific T cells. These T cells would become activated but also upregulate inhibitory checkpoints such as CTLA-4. These can be blocked with the anti CTLA-4 antibody, ipilimumab, to permit enhanced anti-tumor T cell responses (Sharma P and Allison JP. Cell 2015). In addition, the release of tumor antigens may focus the activated immune response on tumor antigens rather than self-antigens, resulting in fewer adverse events (AEs). Patients and Methods: Patients (pts.) with lymphoma or CLL who relapsed after alloSCT, with no active GVHD were eligible. Pts. with autoSCT were included within 6 months post-transplant, if they had high risk features for relapse. Treatment consisted of 4 total cycles of lenalidomide 10 mg PO daily for 21 days (cycles 1 and 3) alternating with ipilimumab 3 mg/kg IV on day 1 (Cycles 2 and 4). Lenalidomide dose reduction was permitted to 5 mg based on standard clinical practice. The primary objective was to evaluate safety and secondary objectives were to assess overall response rate (ORR) and survival. Results: Sixteen pts. were enrolled in the study. Autologous group (n=7): The median age was 55 yrs (range, 33 - 68). Lymphoma histologies included [Double-hit (DHL) (n=3), mantle cell (MCL) (n=3; including 2 with 2 prior transplants, one with CNS involvement), and Hodgkin's disease (n=1 with persistent PET+ post-SCT]. Median time to enrollment after SCT was 3.7 months. Median follow-up was 9.0 months (range, 5.3 - 27.1). All pts. remain alive. One DHL pt. transplanted during second remission relapsed at 1.6 months after just initiating cycle 2 of therapy. All others remain in complete remission (CR). The most common other AEs were 16 events of neutropenia (n=4, gr 4; n=2, gr 3, n=10, gr 2), thrombocytopenia (n=1, gr 2,) and one pt. developed pulmonary embolism on therapy. All AEs resolved. An immune-related AE occurred in one pt. (dermatitis, gr 2) after the second ipilimumab dose and resolved with steroids. Allogeneic group (n=9): The median age was 54 yrs (range, 44- 66). Histologies included [Follicular (n=3), CLL (n=2), MCL (n=2), DHL (n=1), diffuse large cell (n=1), and T-cell anaplastic lymphoma (n=1)]. The median number of therapies excluding the alloSCT was 3 (range 2- 7). Two failed a prior autoSCT, one had 2 prior alloSCT, and 3 failed prior DLIs. Two pts. relapsed within 2 months of their alloSCT prior to enrollment on study. One pt. was taken off study after cycle 1 of lenalidomide due to flare of previously diagnosed GVHD, which responded to steroids and pt. is now off immunosuppression. All others finished planned treatment without GVHD. ORR was 75% (CR 37.5% and PR 37.5%). With a median follow-up time of 9.2 months (range, 3.0-20.9), all pts. remain alive. Three pts. had recurrent disease at a median time of 5.4 months (range, 4.6 -12.0) after stopping therapy. One is showing ongoing response to retreatment. AEs included seven episodes of neutropenia (n=1, gr 4; n=2, gr 3; n =4, gr 2), anemia (n=1, gr 2), diarrhea (n=1, gr 2), nausea (n=1, gr 2), headache (n=1, gr 2), hypertension (n=1, gr 2). All AEs resolved. There were no immune mediated AEs. Immunologic analyses: We conducted 17-color flow cytometric analyses on PBMC pre-, during and post-treatment time points. We observed ~1.5-2-fold increase in ICOS+ CD4+T cells after ipilimumab+lenalidomide combination therapy. We previously identified an increase in ICOS+ CD4+ T cells as a phamacodynamic biomarker of ipilimumab therapy (Ng Tang et al., Cancer Immunology Research, 2014). Although we expected significant differences in immunologic impact of ipilimumab therapy in allogeneic versus autologous transplant pts., our preliminary data indicate similar immune responses in the two groups.Conclusions:Treatment with lenalidomide and ipilimumab after SCT for pts with lymphoid malignancies has a favorable toxicity profile. Our Immunological results, together with the fact that the frequency of AEs was not different between the allogeneic and autologous arms, suggest that combination therapy with lenalidomide and ipilimumab elicits measurable immunologic changes and clinical responses without inducing GVHD. DisclosuresJabbour:ARIAD: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Research Funding; BMS: Consultancy.

Combining ipilimumab with local treatments for melanoma may improve survival

Patients with malignant melanoma who received both ipilimumab (Yervoy) and local peripheral treatments such as radiotherapy and electrochemotherapy had significantly prolonged overall survival in comparison with patients who received only ipilimumab, according to a study conducted by researchers from University Hospital in Cologne, Germany.1 Their work, published in Cancer Immunology Research, involved the analysis of data from 127 patients with malignant melanoma who were treated consecutively at 4 cancer centers in Germany and Switzerland. Eighty-two patients in the group received ipilimumab only, whereas 45 received ipilimumab plus local peripheral treatment to relieve tumor-related symptoms. Findings showed that the median overall survival was 93 weeks for patients in the combined group and 42 weeks for the ipilimumab-only group. The median overall survival benefit for patients receiving ipilimumab in addition to local peripheral treatment remained after the exclusion of patients with brain metastases from the analysis (these patients were excluded because they were not equally distributed between the groups). For patients without brain metastases, the median overall survival was 117 weeks in the combined group and 46 weeks in the ipilimumab-only group. Lead author Sebastian Theurich, MD, notes that the survival advantage seemed to overcome traditional risk factors for poor outcomes, and this suggests that the combination could benefit all patients with malignant melanoma. The data echo the results of a previous study of 29 patients in the United States who were treated with ipilimumab and local radiotherapy, says Dr. Theurich, and this further validates his team's results. The researchers have also begun investigating whether adding local peripheral treatments activates patients' immune cells; they are exploring this question further in prospective studies.

Application of the Immunoscore as prognostic tool for hepatocellular carcinoma

To date, the American Joint Committee on Cancer (AJCC) and the Union for International Cancer Control (UICC) tumor, nodes, metastasis (TNM) classification represents the standard system for evaluation of prognosis...

Abstract IA26: Combinatorial immunotherapies with the potential to reverse the carcinogenesis process

Abstract Until recently, barriers to immunotherapy clinical successes for pancreatic cancer have been due to a lack of understanding of the immune pathways within the pancreatic tumor microenvironment that hinder successful immune responses. Recent advances have identified new targets for developing cancer specific vaccines and new targets for modulating the tumor microenvironment to allow more potent activation and improved access of vaccine induced immune responses. We are just learning that non-neoplastic cells, including cancer-associated myofibroblasts, regulatory T cells, dendritic cells, myeloid-derived suppressor cells, and tumor-associated macrophages, are hijacked by pre-invasive and invasive cancer cells to create a tolerogenic tumor microenvironment. Current research is focused on elucidating the mechanisms of this tolerogenic polarization within the tumor microenvironment with the goal of tipping the balance in favor of an anticancer immune response. With the recent advances in molecular technologies and the development of relevant pancreatic cancer mouse models, it is now within our reach to dissect the inhibitory pathways within the pancreatic tumor microenvironment. This will in turn, lead to new therapeutic opportunities that will eliminate these barriers and convert this deadly cancer into a treatable disease.

Abstract B140: Autologous human growing tumor model and its immunological relevance for cancer immunology research

Abstract Background: Tumors grow in accordance with immunoediting. If we can see the changes of immune characteristics in the microenvironment during tumor growth, we can have much information of the mechanism of immunoediting. Peritoneal tumor cells from colorectal cancers are mostly derived from the shedding of tumor cells exposed on the visceral peritoneum. After the surgical removal of the primary tumors of which cells are exposed on the visceral peritoneum (T4 stage) but without macroscopic tumor seedings in the peritoneal cavity, some patients experience peritoneal recurrence but others do not. This implies that in the patients with future peritoneal recurrences the microscopic tumor cells in the peritoneal cavity have already been immunoedited. In addition, ascites and peritoneal immune cells are components of tumor microenvironment during peritoneal tumor growth if the peritoneal cavity is not contaminated by microorganisms by bowel perforation. And ascites and peritoneal cells are appropriate materials for immediate analysis after collection. Therefore, if we establish peritoneal immune characteristics of each T4 patient and compare those between the recurred and non-recurred patients in the peritoneal cavity afterwards, we can hold the clues of immunoediting during the peritoneal tumor growth. In this study we tested this autologous human growing tumor model for the relevance of research subject for cancer-associated immune response, as a pilot study. Method: Ascites and peritoneal cells were collected during the operation of colon cancer patients. If blood were mixed during the collection, the ascites and cells were discarded. The patients, whose ascites and peritoneal cells had been harvested, were classified into four groups (PC stages) according to the progression of peritoneal tumor growth on the basis of pathological report. SE-(serosa exposure negative; no tumor cells in peritoneal cavity) is a group of patients without exposure of cancer cells to peritoneal cavity (T3 or lower T stage). SE+(serosa exposure positive; microscopic tumor cells in peritoneal cavity) is a group of patients of T4 lesion without peritoneal seedings. l-PC represents localized peritoneal seedings which could be removed entirely during surgery. g-PC is a group of generalized peritoneal seeding. We performed ELISA and flow cytometry analysis as well as immune cell activation. Result: Of the 10 cytokines assayed in ascites, IL10, IL6 and TGF-beta increased according to the tumor progression in the peritoneal cavity, while the other cytokines (IL2, IL4, IL5, IL12, IL17, TNF and IFN-gamma) did not show any changes. Of the 42 SE+ patients, eleven experienced peritoneal recurrences. Mean IL10 (42 vs 24 pg/mL) and IL6 (2,092 vs 4472 pg/mL) levels of patients with peritoneal recurrence were higher than those without recurrence although we could not have significance (P = 0.113 and 0.180 each, Mann-Whitney U test). Activation of peritoneal cells by LPS increased IL6 as well as IL10 while activation by antiCD3 and antiCD28 did not. Intracellular IL10 was stained in T cells while IL6 in CD14 cells after LPS stimulation. Moreover, although ascitic IL6 increased up to tens of thousands pg/mL in g-PC patients, the blood level stayed at tens pg/mL. This means the ascites and peritoneal immune cells belong to a microenvironment which is seldom reflected in peripheral blood. Conclusion: This model showed the possibility of relevance to explore cancer-associated immune response in the tumor microenvironment during tumor growth in colorectal cancer. It is expected that further studies will provide much information of the mechanism of suppression of anti-tumor immune response. And the results derived from this model can help to extend understandings of immunoediting in primary tumors, metastatic tumors and, further, in other cancers. Citation Format: Seung Chul Heo, Sang Mok Lee, Beonghoon Sohn, Ji-Eun Kim, Rumi Shin. Autologous human growing tumor model and its immunological relevance for cancer immunology research [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B140.

PD-L1 biomarker testing for non-small cell lung cancer: truth or fiction?

Research in cancer immunology is currently accelerating following a series of cancer immunotherapy breakthroughs during the last 5 years. Various monoclonal antibodies which block the interaction between checkpoint molecules PD-1...

Circulating protein and antibody biomarker for personalized cancer immunotherapy

Immune checkpoint blockade therapies are revolutionizing standard cancer treatments. Immune checkpoint inhibitors likely function to enhance the tumor specific antigen response in order to achieve favorable clinical outcomes. Thus, continuous...

Remote Controlled CARs: Towards a Safer Therapy for Leukemia.

Genetic engineering of patient T cells with chimeric antigen receptors (CAR T cells) provides a powerful tool for inducing remissions in patients with various cancers derived from B cells. Challenges stemming from the inability to control the CAR T cells once given pose significant safety concerns. An article in Cancer Immunology Research presents an approach to circumvent this issue. Cancer Immunol Res; 4(8); 643. ©2016 AACRSee article by Sakemura et al., p. 658.

Abstract IA16: Tipping the balance from a procarcinogenic to an antitumor microenvironment in pancreatic cancers

Abstract Until recently, barriers to immunotherapy clinical successes for pancreatic cancer have been due to a lack of understanding of the immune pathways within the pancreatic tumor microenvironment that hinder successful immune responses. Recent advances have identified new targets for developing cancer specific vaccines and new targets for modulating the tumor microenvironment to allow more potent activation and improved access of vaccine induced immune responses. We are just learning that non-neoplastic cells, including cancer-associated myofibroblasts, regulatory T cells, dendritic cells, myeloid-derived suppressor cells, and tumor-associated macrophages, are hijacked by pre-invasive and invasive cancer cells to create a tolerogenic tumor microenvironment. Current research is focused on elucidating the mechanisms of this tolerogenic polarization within the tumor microenvironment with the goal of tipping the balance in favor of an anticancer immune response. With the recent advances in molecular technologies and the development of relevant pancreatic cancer mouse models, it is now within our reach to dissect the inhibitory pathways within the pancreatic tumor microenvironment. This will in turn, lead to new therapeutic opportunities that will eliminate these barriers and convert this deadly cancer into a treatable disease. Building on our extensive experience developing immunotherapies for pancreatic cancer, we are now developing combinatorial immunotherapies that combine T cell inducing agents with agents that modulate T cell down regulatory signals within the tumor microenvironment. These studies have shown for the first time that traditionally “non-immunogenic” cancers that do not respond to single agent immune modulating agents, can be converted into tumors susceptible to these agents if a T cell inducing vaccine is given together with these immune modulating agents. Results from both pre-clinical and clinical studies will be discussed.

Tales of Antigen Evasion from CAR Therapy

Both T cells bearing chimeric antigen receptors and tumor-specific antibodies can successfully target some malignancies, but antigen escape can lead to relapse. Two articles in this issue of Cancer Immunology Research explore what effective countermeasures may prevent it. Cancer Immunol Res; 4(6); 473-473. ©2016 AACRSee articles by Zah et al., p. 498, and Rufener et al., p. 509.

Looking to the future in an unprecedented time for cancer drug development

Basic research in cancer biology, genetics and immunology has resulted in improved insights into mechanisms that drive tumor initiation and growth. This improved biologic understanding of the diseases we treat has led to unprecedented therapeutic breakthroughs across multiple tumor types. In this article, we discuss opportunities and challenges in contemporary cancer drug development, highlighting efficacy endpoints, clinical trial design and the thoughtful inclusion of the patient perspective. As the field re-examines old practices and explores new opportunities, we must continue to efficiently utilize the human and scientific resources at our disposal to foster the development and delivery of safe and effective therapies to cancer patients.

MIF inhibition reverts the gene expression profile of human melanoma cell line-induced MDSCs to normal monocytes.

Myeloid-derived suppressor cells (MDSCs) are potently immunosuppressive innate immune cells that accumulate in advanced cancer patients and actively inhibit anti-tumor T lymphocyte responses [1]. Increased numbers of circulating MDSCs directly correlate with melanoma patient morbidity and reduced anti-tumor immune responses [2], [3]. Previous studies have revealed that monocyte-derived macrophage migration inhibitory factor (MIF) is necessary for the immune suppressive function of MDSCs in mouse models of melanoma [4], [5]. To investigate whether MIF participates in human melanoma-induced MDSC differentiation and/or suppressive function, we have established an in vitro MDSC induction model using primary, normal human monocytes co-cultured with human melanoma cell lines in the presence or absence of the MIF antagonist—4-IPP [4], [6], [7], [8], [9]. To identify potential mechanistic effectors, we have performed transcriptome analyses on cultured monocytes and on melanoma-induced MDSCs obtained from either untreated or 4-IPP-treated A375:monocyte co-cultures. Here, we present a detailed protocol, which can facilitate easy reproduction of the microarray results (NCBI GEO accession number GSE73333) published by Yaddanapudi et al. (2015) in Cancer Immunology Research [10].

Abstract PL04-03: Fatal Attraction: A new story featuring the immune system and pancreatic cancer

Abstract Until recently, barriers to immunotherapy clinical successes for pancreatic cancer have been due to a lack of understanding of the immune pathways within the pancreatic tumor microenvironment that hinder successful immune responses. Recent advances have identified new targets for developing cancer specific vaccines and new targets for modulating the tumor microenvironment to allow more potent activation and improved access of vaccine induced immune responses. We are just learning that non-neoplastic cells, including cancer-associated myofibroblasts, regulatory T cells, dendritic cells, myeloid-derived suppressor cells, and tumor-associated macrophages, are hijacked by pre-invasive and invasive cancer cells to create a tolerogenic tumor microenvironment. Current research is focused on elucidating the mechanisms of this tolerogenic polarization within the tumor microenvironment with the goal of tipping the balance in favor of an anticancer immune response. With the recent advances in molecular technologies and the development of relevant pancreatic cancer mouse models, it is now within our reach to dissect the inhibitory pathways within the pancreatic tumor microenvironment. This will in turn, lead to new therapeutic opportunities that will eliminate these barriers and convert this deadly cancer into a treatable disease. Building on our extensive experience developing immunotherapies for pancreatic cancer, we are now developing combinatorial immunotherapies that combine T cell inducing agents with agents that modulate T cell down regulatory signals within the tumor microenvironment. These studies have shown for the first time that traditionally “non-immunogenic” cancers that do not respond to single agent immune modulating agents, can be converted into tumors susceptible to these agents if a T cell inducing vaccine is given together with these immune modulating agents. Results from both pre-clinical and clinical studies will be discussed.

Cancer immunotherapy out of the gate: the 22nd annual Cancer Research Institute International Immunotherapy Symposium.

The 22nd annual Cancer Research Institute (CRI) International Immunotherapy Symposium was held from October 5-8, 2014, in New York City. Titled "Cancer Immunotherapy: Out of the Gate," the symposium began with a Cancer Immunotherapy Consortium satellite meeting focused on issues in immunotherapy drug development, followed by five speaker sessions and a poster session devoted to basic and clinical cancer immunology research. The second annual William B. Coley lecture was delivered by Lieping Chen, one of the four recipients of the 2014 William B. Coley Award for Distinguished Research in Tumor Immunology; the other three recipients were Gordon Freeman, Tasuku Honjo, and Arlene Sharpe. Prominent themes of the conference were the use of genomic technologies to identify neoantigens and the emergence of new immune modulatory molecules, beyond CTLA-4 and PD-1/PD-L1, as new therapeutic targets for immunotherapy.