Failure Of Immunotherapy Research Articles

Modelling the immunosuppressive effect of liver SBRT by simulating the dose to circulating lymphocytes: an in-silico planning study

BackgroundTumor immune-evasion and associated failure of immunotherapy can potentially be overcome by radiotherapy, which however also has detrimental effects on tumor-infiltrating and circulating lymphocytes (CL). We therefore established a model to simulate the radiation-dose delivered to CL.MethodsA MATLAB-model was established to quantify the CL-dose during SBRT of liver metastases by considering the factors: hepatic blood-flow, −velocity and transition-time of individual hepatic segments, as well as probability-based recirculation. The effects of intra-hepatic tumor-location and size, fractionation and treatment planning parameters (VMAT, 3DCRT, photon-energy, dose-rate and beam-on-time) were analyzed. A threshold dose ≥0.5Gy was considered inactivating CL and CL0.5 (%) is the proportion of inactivated CL.ResultsMean liver dose was mostly influenced by treatment-modality, whereas CL0.5 was mostly influenced by beam-on-time. 3DCRT and VMAT (10MV-FFF) resulted in lowest CL0.5 values of 16 and 19%. Metastasis location influenced CL0.5, with a mean of 19% for both apical and basal and 31% for the central location. PTV-volume significantly increased CL0.5 from 27 to 67% (10MV-FFF) and from 31 to 98% (6MV-FFF) for PTV-volumes ranging from 14cm3 to 268cm3.ConclusionA simulation-model was established, quantifying the strong effects of treatment-technique, tumor-location and tumor-volume on dose to CL with potential implications for immune-optimized treatment-planning in the future.

Head and Neck Squamous Cell Carcinomas Are Characterized by a Stable Immune Signature Within the Primary Tumor Over Time and Space.

Purpose: Genetic and morphologic heterogeneity is well-documented in solid cancers. Immune cells are also variably distributed within the tumor; this heterogeneity is difficult to assess in small biopsies, and may confound our understanding of the determinants of successful immunotherapy. We examined the transcriptomic variability of the immunologic signature in head and neck squamous cell carcinoma (HNSCC) within individual tumors using transcriptomic and IHC assessments.Experimental Design: Forty-four tumor biopsies from 16 HNSCC patients, taken at diagnosis and later at resection, were analyzed using RNA-sequencing. Variance filtering was used to identify the top 4,000 most variable genes. Principal component analysis, hierarchical clustering, and correlation analysis were performed. Gene expression of CD8A was correlated to IHC analysis.Results: Analysis of immunologic gene expression was highly consistent in replicates from the same cancer. Across the cohort, samples from the same patient were most similar to each other, both spatially (at diagnosis) and, notably, over time (diagnostic biopsy compared with resection); comparison of global gene expression by hierarchical clustering (P ≤ 0.0001) and correlation analysis [median intrapatient r = 0.82; median interpatient r = 0.63]. CD8A gene transcript counts were highly correlated with CD8 T-cell counts by IHC (r = 0.82).Conclusions: Our data demonstrate that in HNSCC the global tumor and adaptive immune signatures are stable between discrete parts of the same tumor and also at different timepoints. This suggests that immunologic heterogeneity may not be a key reason for failure of immunotherapy and underpins the use of transcriptomics for immunologic evaluation of novel agents in HNSCC patients. Clin Cancer Res; 23(24); 7641-9. ©2017 AACR.

The Pancreatic Cancer Microenvironment.

Pancreatic ductal adenocarcinoma (PDAC) is composed of a minority of malignant cells within a microenvironment of extracellular matrix, fibroblasts, endothelial cells, and immune cells. Therapeutic failures of chemotherapy, targeted therapy, and immunotherapy have all been attributed to the PDAC microenvironment. In this review, we dissect the components of the microenvironment and explain how each cell type contributes to form a highly immunosuppressive, hypoxic, and desmoplastic cancer. New efforts in single-cell profiling will enable a better understanding of the composition of the microenvironment in primary and metastatic PDAC, as well as an understanding of how the microenvironment may respond to novel therapeutic approaches.

Binimetinib for the treatment of NRAS-mutant melanoma

ABSTRACTIntroduction: Activating NRAS mutations occur in approximately 15–20% of melanomas and are the second most common oncogenic driver mutation in this disease, after BRAF mutations. There is an unmet medical need for new targeted therapy opportunities in metastatic patients whose tumors harbor an NRAS mutation. Binimetinib, a mitogen-activated protein kinase kinase (MEK) inhibitor, has shown clinical activity in this group of patients.Areas covered: The purpose of this paper was to review the safety, activity and efficacy of the MEK inhibitor binimetinib for the treatment of NRAS-mutant melanoma, as well as to discuss future therapeutic perspectives such as multiple pathways, targeted therapy, and combinations with immunotherapy.Expert commentary: Only a modest progression-free survival (PFS) benefit was observed in NRAS-mutated patients who received binimetinib compared with dacarbazine in a randomized phase 3 clinical trial, with no improvement in overall survival. Nevertheless, binimetinib represents another promising treatment option for advanced melanoma and the first molecularly targeted therapy for the NRAS-mutant population. Binimetinib may also have a role in treating NRAS-mutated melanoma patients after failure of immunotherapy.

Excellent response to chemotherapy post immunotherapy.

IntroductionImmunotherapy in the form of immune checkpoint inhibitors has changed the landscape of cancer treatment. Newer monoclonal antibodies are coming up and are being tested in various cancers during different stages of treatment. With the increasing use of immune checkpoint inhibitors in the management of various types of cancers, the question is raised as to what next can be offered to a patient who has progressed on this newer treatment. Does Sequence matter? There have been reports of improved responses to chemotherapy after immunotherapy in the form of vaccines. Here we present a case series of 6 patients who progressed on immunotherapy with immune checkpoint inhibitors after initial modality of treatment (chemotherapy/radiation), subsequently received chemotherapy with excellent response.MethodsWe have a cohort of six patients who had disease progression on second line Immunotherapy for solid or hematological malignancies and had ECOG < 2. All these patients received third line salvage chemotherapy. Three patients had metastatic head and neck cancer, 2 had non-small cell lung cancer (NSCLC), and one had T -cell rich B- cell lymphoma. Prior review and approval were obtained from our institutional review board.ResultsAll patients had an excellent response to chemotherapy in third line setting, after immune checkpoint inhibitors and most of them achieved a complete response.ConclusionTargeting cancer with chemotherapy after failure of immunotherapy is a valid option and can lead to better response rates and PFS which may lead to OS. This effect may be secondary to immunotherapy removing the inhibition exerted by tumor cells or other immune cells initially followed by cytotoxic chemotherapy mediated killing of tumor cells.

Abstract 2995: Development of a novel highly potent TLR8 selective agonist for cancer immunotherapy

Abstract The cancer drug discovery field is experiencing unprecedented revolution accompanied by growing excitement from researchers, drug developers, patients and investors, partly due to recent clinical success of cancer immunotherapy. Human immune defense system comprises both innate and adaptive immune pathways. All the targets drugged by the recently approved cancer immunotherapeutic agents including the immune checkpoint proteins PD-1, PD-L1 and CTLA-4 function in adaptive immune pathways. In contrast, targets involved in the innate immune pathway have not matured to regulatory approval for systemic use though several candidates are now in preclinical and clinical development. Drugs targeting innate immunity represent great opportunity for more rapid and broader spectrum anti-cancer effect than adaptive immunity. Furthermore, combinations of drugs targeting innate and adaptive immunity are expected to produce strong synergistic efficacy owing to their complementary nature as body’s immune defense. Toll-like receptors (TLRs) are a family of proteins that recognize pathogen associated molecular patterns (PAMPs). Their primary function is to activate innate immune responses while also involved in facilitating adaptive immune responses. Different TLRs exert distinct functions by activating varied immune cascades. TLR8 is more broadly expressed in immune cells than other TLRs such as TLR7 and TLR9. One of the major causes of cancer immunotherapy failure is potent suppression of immune response by Treg cells. TLR8 is the only TLR that has been shown to be necessary and sufficient to reverse the suppressive function of Treg cells leading to strong tumor inhibition. Therefore, agonists targeting TLR8 are expected to be effective cancer therapy. However, there is no approved TLR8 selective agonist at present. There is only one TLR8 selective agonist in clinical development. Through structure-based drug design, we discovered a novel, highly potent and selective small molecule TLR8 agonist, DN-A1. DN-A1 exhibited strong in vitro cellular activity with EC50 at 4.23 nM, about 30-fold more potent than the only drug candidate in clinical trials. The activity was highly selective for TLR8 over other TLRs. DN-A1 displayed superior in vitro ADMET and in vivo PK profiles. DN-A1 showed clean CYP profile with IC50 over 10 μM for all major CYP isoenzymes tested including 3A4, 1A2, 2C9, 2C19 and 2D6. DN-A1 had favorable hERG parameter with IC50 over 30 μM whereas the reference compound’s hERG IC50 was 3.84 μM suggesting potential cardiac toxicity. DN-A1 significantly impeded tumor growth as a single agent and was well-tolerated in mouse tumor models. Taken together, DN-A1 warrants further development as a potential best-in-class preclinical drug candidate for TLR8-mediated cancer immunotherapy. Citation Format: Yuxun Wang, Heping Yang, Longsheng Wang, Guangliang Fu, Fang Bao, Fang Liu, Shuwen Ren, Huanping Li, Haixia Ji, Yajun Yu, Zhiheng Wu, Panhu Zhu, Hui Xu, Yaqiao Gao, Pei Wang, Shoujun Chen, Daxin Gao. Development of a novel highly potent TLR8 selective agonist for 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 2995. doi:10.1158/1538-7445.AM2017-2995

Modeling the Dichotomy of the Immune Response to Cancer: Cytotoxic Effects and Tumor-Promoting Inflammation.

Although the immune response is often regarded as acting to suppress tumor growth, it is now clear that it can be both stimulatory and inhibitory. The interplay between these competing influences has complex implications for tumor development, cancer dormancy, and immunotherapies. In fact, early immunotherapy failures were partly due to a lack in understanding of the nonlinear growth dynamics these competing immune actions may cause. To study this biological phenomenon theoretically, we construct a minimally parameterized framework that incorporates all aspects of the immune response. We combine the effects of all immune cell types, general principles of self-limited logistic growth, and the physical process of inflammation into one quantitative setting. Simulations suggest that while there are pro-tumor or antitumor immunogenic responses characterized by larger or smaller final tumor volumes, respectively, each response involves an initial period where tumor growth is stimulated beyond that of growth without an immune response. The mathematical description is non-identifiable which allows an ensemble of parameter sets to capture inherent biological variability in tumor growth that can significantly alter tumor-immune dynamics and thus treatment success rates. The ability of this model to predict non-intuitive yet clinically observed patterns of immunomodulated tumor growth suggests that it may provide a means to help classify patient response dynamics to aid identification of appropriate treatments exploiting immune response to improve tumor suppression, including the potential attainment of an immune-induced dormant state.

Current Perspective on In Vivo Molecular Imaging of Immune Cells.

Contemporaneous development of improved immune cell-based therapies, and powerful imaging tools, has prompted growth in technologies for immune cell tracking in vivo. Over the past couple of decades, imaging tools such as magnetic resonance imaging (MRI) and optical imaging have successfully monitored the trafficking patterns of therapeutic immune cells and assisted the evaluation of the success or failure of immunotherapy. Recent advancements in imaging technology have made imaging an indispensable module of immune cell-based therapies. In this review, emerging applications of non-radiation imaging modalities for the tracking of a range of immune cells are discussed. Applications of MRI, NIR, and other imaging tools have demonstrated the potential of non-invasively surveying the fate of both phagocytic and non-phagocytic immune cells in vivo.

Chimeric antigen receptor (CAR) T cells genetically engineered to deliver IL-12 to the tumor microenvironment in ovarian cancer.

3050 Background: Chimeric antigen receptor (CAR) T cell therapy for solid tumor malignancies has not shown the same degree of clinical efficacy observed in hematologic malignancies. The presence of an immunosuppressive cytokine and cellular microenvironment has been hypothesized as one reason for the failure of adoptive immunotherapy for solid tumors. In ovarian cancer, the presence of tumor associated macrophages (TAMs) and immunosuppressive cytokines in the ascitic microenvironment have been reported. IL-12 is a proinflammatory cytokine produced by macrophages, dendritic cells (DC) and NK cells, and has been shown to increase proliferation of T cells and enhance antigen presentation by macrophages. We hypothesized that CAR T cells genetically modified to constitutively secrete IL-12 would overcome a hostile tumor microenvironment in a peritoneal carcinomatosis model of ovarian cancer. Methods: CAR T cells were generated from retroviral transduction of second generation and IL-12 modified CAR’s directed to either an irrelevant CD-19 antigen or Muc16ecto. Results: Here we report increased production of IL-12, improved proliferation and cytotoxic activity of 4H1128-IL12 CAR T cells. We show increased levels of inflammatory cytokines at 24 and 48hrs after treatment of tumor-bearing mice, leading to increased survival at advanced stages of disease. Mice treated with 4H1128-IL12 CAR T cells had decreased levels of F4/80+ CD11b+TAM’s. Genetic analysis of recovered TAM’s from the ascites of treated animals showed skewing towards an M1-phenotype via upregulation of cytokines, chemokines, MHC-II and downregulation of Arg1. Recovered 4H1128-IL12 CAR T cells showed upregulation of FAS-L and recovered TAMs showed increased expression of FAS suggesting FAS/FAS-L engagement was responsible for decreased TAMs. Blocking the FAS/FAS-L pathway led to recovery of TAM populations in 4H1128-IL12 treated mice. Finally, clodronate-mediated depletion of TAM’s further enhanced survival in mice treated with 4H1128-IL12 CAR T cells. Conclusions: These results demonstrate the mechanisms of efficacy of localized delivery of IL-12 to the tumor microenvironment by 4H1128-IL12 CAR T cells.

Small cell lung cancer: The immune microenvironment and prognostic impact of checkpoint expression.

8569 Background: To date, immunotherapy has had limited success in small cell lung cancer (SCLC), despite the tumor’s high mutation load. Little is understood of the immune tumor microenvironment in SCLC due to a paucity of resected tumor. We present a SCLC cohort and describe the prognostic impact of checkpoint expression. Methods: SCLC tissue microarrays with triplicate cores from 105 SCLC specimens underwent IHC assessment for PD-L1, PD-L2, LAG3, TIM3, FoxP3, CD4 and CD8 on tumor and/or tumor infiltrating lymphocytes (TILs). Checkpoint positivity was defined &gt; 5% tumor expression or TIL expression in &gt; 5% of the total core area. Associations with clinicopathologic characteristics and survival were assessed. A Cox model was used for univariate and multivariate survival analysis. Results: Tumor expression of PD-L1 was positive (+) in 17/95 (18%), PD-L2+ in 2/96 (2%), and TIM3+ or LAG3+ in no cases. TILs expressed PD-L1+ in 64/95 (67%), PD-L2+ in 22/96 (22%), TIM3+ in 57/96 (59%) and LAG3+ in 43/96 (45%). FoxP3+ lymphocytes were found in all samples (range 0.02 – 2.98% of total core). TIL expression of PD-L1, PD-L2, TIM3 and LAG3 were all significantly correlated (p value ≤0.001 for all comparisons), and were associated with high FoxP3+ expression. All four checkpoints were expressed on TILs in 20/105 (19%) patients. PD-L1+ and PD-L2+, but not TIM3 or LAG3, on TILs were significantly higher in limited stage compared with extensive stage SCLC (76% v 52%, p 0.045 and 28% v 7%, p 0.02 respectively). There was no association between stage and tumor expression. TIL expression of PD-L1, PD-L2, TIM3 and LAG3 were all associated with improved prognosis. PD-L1+ median OS: 17.2 v 7.9 months (HR 0.36; 95%CI 0.22 – 0.6; p &lt; 0.001). Univariate analysis showed stage and TIL expression of PD-L1, PD-L2, TIM3 and LAG3 were associated with improved survival, but only stage and PD-L1+ TILs remained significant on multivariate analysis (p &lt; 0.01). Conclusions: Immune checkpoint molecules are frequently expressed in SCLC-associated TILs, but not the tumor itself. TIL expression of checkpoint molecules is associated with improved survival. Limited tumor expression of PD-L1 and an exhausted immune cell phenotype may contribute to immunotherapy failure.

Antiepileptic drug therapy in patients with autoimmune epilepsy.

Objective:We aimed to report the pattern of usage and efficacy of antiepileptic drugs (AEDs) in patients with autoimmune epilepsy (AE).Methods:We retrospectively studied the Mayo Clinic's electronic medical record of patients with AE in which seizures were the main presenting feature. Clinical data, including demographics, seizure characteristics, type of AED and immunotherapy used, presence of neural antibody, and treatment outcomes, were reviewed.Results:The medical records of 252 adult patients diagnosed with autoimmune encephalitis and paraneoplastic disorders were reviewed. Seizure was the initial presentation in 50 patients (20%). Serum and/or CSF autoantibodies were detected in 41 (82%) patients, and 38 (76%) patients had neural autoantibodies. The majority (n = 43, 86%) received at least 1 form of immunotherapy in combination with AEDs, while the remainder received AEDs alone. Twenty-seven patients (54%) became seizure free: 18 (36%) with immunotherapy, 5 (10%) with AEDs alone, and 4 (8%) with AEDs after immunotherapy failure. Levetiracetam was the most commonly used (42/50); however, it was associated with 0% seizure-free response. AED seizure-free responses occurred with carbamazepine (n = 3) [3/16, 18.8%], lacosamide (n = 3) [3/18, 16.6%] with phenytoin (n = 1) [1/8, 12.5%], or oxcarbazepine (n = 2) [2/11, 18.1%]. Regardless of the type of therapy, voltage-gated potassium channel-complex antibody–positive patients were more likely to become seizure free compared with glutamic acid decarboxylase 65 antibody–positive cases (12/17 vs 2/10, p = 0.0183).Conclusions:In select patients, AEDs alone were effective in controlling seizures. AEDs with sodium channel blocking properties resulted in seizure freedom in a few cases. Prospective studies are needed to clarify AED selection and to elucidate their immunomodulatory properties in AE.

Efficacy of combining radiotherapy and immunotherapy for metastatic colorectal cancer and the modulation of tumor microenvironment

Abstract Immune checkpoint blockade antibodies specific to programed death-1/ligand-1 (PD-1/PD-L1) shows durable clinical responses in various cancers but benefit only to a small portion of patients. The failure of immunotherapy is likely due to the complex network of immunosuppressive mechanisms present in advanced tumors. Radiation (RT) modifies tumor microenvironment and causes tumor antigen release, and thus augment efficacy of immunotherapy. Interleukin 12 (IL-12) and granulocyte macrophage colony-stimulator factor (GM-CSF) have shown potent antitumor activities through activating innate and adaptive immunities, as well as reprogramming myeloid cells to a phenotype that favors immune activation. The aim of this project is to compare the therapeutic efficacy of two types of combination therapy: RT combined with IL-12/GM-CSF (RT/12GM) versus RT combined with anti-PD-L1 antibody (RT/PD-L1), and to dissect the molecular mechanisms of the antitumor responses. Our data showed that RT/12GM led to tumor regression in a majority of mice with large established tumors and suppressed liver metastasis, while RT/PD-L1 could only suppress primary tumors but not metastatic tumor. Mechanistic analysis showed that RT/12GM was superior to RT/PD-L1 in inducing accumulation of CD8+ T cells in tumor and in augmenting both NK and CD8+ T cells cytotoxicity in tumor and liver. Interestingly, RT/12GM also induced infiltration of tumor-associated neutrophils (TAN) and impaired their immunosuppressive functions. Depletion experiments showed that both CD8+ T cell and TAN were required for tumor regression in RT/12GM. Together, our results demonstrate that RT/12GM represent a powerful alternative therapy against both primary and metastatic tumors.

Sodium Selenite as an Anticancer Agent.

Selenium (Se) is a ubiquitous, albeit not uniformly distributed metalloid present in earth crust. Consequently, its human intake with food products, particularly grains and vegetables, is also very uneven, and in certain cases can result in a severe Se deficiency. It was also documented that Se deficiency observed in some countries and/or geographic regions (e.g. Keshan region in China), is associated with an increased morbidity and mortality of neoplastic diseases. To correct this problem a number of organic and inorganic selenium compounds were developed and tested. However, it is now firmly established that only an inorganic sodium selenite with four-valent Se, and not that with six-valent (selenate) cation shows anticancer activity. This difference in their biological activities is due to their physicochemical properties. Thus selenite (Se+4) can undergo redox reaction, for example with protein's sulfhydryl groups expressed on the surface of tumor cells. In this way selenite prevents non-enzymatic formation of parafibrin that coats tumors cells and hence presents them as 'self' to the innate cellular immune system. Consequently, macrophages of the lymphatic system do not recognize neoplastic cells as 'foreign' bodies and spare them from the immune destruction. This mechanism can explain the failure of various immunotherapies to completely eliminate tumors from human bodies. Another contributing factor to carcinogenesis is the excessive consumption of red meat containing redox-active iron (Fe+3) that initiates parafibrin formation from blood fibrinogen. In conclusion, sodium selenite is a readily available and inexpensive drug of choice in the cancer treatment and prevention.

Binimetinib versus dacarbazine in patients with advanced NRAS-mutant melanoma (NEMO): a multicentre, open-label, randomised, phase 3 trial

There are no established therapies specific for NRAS-mutant melanoma despite the emergence of immunotherapy. We aimed to assess the efficacy and safety of the MEK inhibitor binimetinib versus that of dacarbazine in patients with advanced NRAS-mutant melanoma. NEMO is an ongoing, randomised, open-label phase 3 study done at 118 hospitals in 26 countries. Patients with advanced, unresectable, American Joint Committee on Cancer stage IIIC or stage IV NRAS-mutant melanoma who were previously untreated or had progressed on or after previous immunotherapy were randomised (2:1) to receive either binimetinib 45 mg orally twice daily or dacarbazine 1000 mg/m2 intravenously every 3 weeks. Randomisation was stratified by stage, performance status, and previous immunotherapy. The primary endpoint was progression-free survival assessed by blinded central review in the intention-to-treat population. Safety analyses were done in the safety population, consisting of all patients who received at least one study drug dose and one post-baseline safety assessment. This study is registered with ClinicalTrials.gov, number NCT01763164 and with EudraCT, number 2012-003593-51. Between Aug 19, 2013, and April 28, 2015, 402 patients were enrolled and randomly assigned, 269 to binimetinib and 133 to dacarbazine. Median follow-up was 1·7 months (IQR 1·4-4·1). Median progression-free survival was 2·8 months (95% CI 2·8-3·6) in the binimetinib group and 1·5 months (1·5-1·7) in the dacarbazine group (hazard ratio 0·62 [95% CI 0·47-0·80]; one-sided p<0·001). Grade 3-4 adverse events seen in at least 5% of patients the safety population in either group were increased creatine phosphokinase (52 [19%] of 269 patients in the binimetinib group vs none of 114 in the dacarbazine group), hypertension (20 [7%] vs two [2%]), anaemia (five [2%] vs six [5%]), and neutropenia (two [1%] vs ten [9%]). Serious adverse events (all grades) occurred in 91 (34%) patients in the binimetinib group and 25 (22%) patients in the dacarbazine group. Binimetinib improved progression-free survival compared with dacarbazine and was tolerable. Binimetinib might represent a new treatment option for patients with NRAS-mutant melanoma after failure of immunotherapy. Array BioPharma and Novartis Pharmaceuticals Corporation.

A comprehensive review of immunotherapies in prostate cancer.

Prostate cancer is the second most common malignant neoplasm in men worldwide and the fifth cause of cancer-related death. Although multiple new agents have been approved for metastatic castration resistant prostate cancer over the last decade, it is still an incurable disease. New strategies to improve cancer control are needed and agents targeting the immune system have shown encouraging results in many tumor types. Despite being attractive for immunotherapies due to the expression of various tumor associated antigens, the microenvironment in prostate cancer is relatively immunosuppressive and may be responsible for the failures of various agents targeting the immune system in this disease. To date, sipuleucel-T is the only immunotherapy that has shown significant clinical efficacy in this setting, although the high cost and potential trial flaws have precluded its widespread incorporation into clinical practice. Issues with patient selection and trial design may have contributed to the multiple failures of immunotherapy in prostate cancer and provides an opportunity to tailor future studies to evaluate these agents more accurately. We have reviewed all the completed immune therapy trials in prostate cancer and highlight important considerations for the next generation of clinical trials.

Chimeric antigen receptor (CAR) T cells genetically engineered to deliver IL-12 to the tumor microenvironment in ovarian cancer.

141 Background: Chimeric antigen receptor (CAR) T cell therapy for solid tumor malignancies has not shown the same degree of clinical efficacy observed in hematologic malignancies such as B-ALL. The presence of an immunosuppressive cellular and cytokine microenvironment has been hypothesized as one reason for the failure of adoptive immunotherapy for solid tumors. In ovarian cancer, myeloid derived suppressor cells (MDSC) and immunosuppressive cytokines in the ascitic microenvironment have been reported. IL-12 is a proinflammatory cytokine produced by macrophages, dendritic cells (DC), and NK cells, and it has been shown to increase proliferation of T cells, induce differentiation of type 1 T helper cells, inhibit regulatory T cells, promote maturation of DCs, and enhance antigen presentation by macrophages. We hypothesize that CAR T cells genetically modified to constitutively secrete IL-12 will overcome a hostile tumor microenvironment in a peritoneal carcinomatosis model of ovarian cancer. Methods: CAR T cells were generated from retroviral transduction of second generation and IL-12 modified CAR’s directed to either an irrelevant CD-19 antigen or Muc16ecto. C57BL/6 mice were inoculated i.p with syngeneic ovarian cancer cells and treated with various CAR T cells. Results: Here we report increased production of IL-12, improved proliferation and cytotoxic activity of 4H1128ζ-IL12 CAR T cells. Further, we show increased levels of inflammatory cytokines at 24 and 48hrs after treatment of tumor-bearing mice, leading to increased survival at advanced stages of disease. Animals treated with 4H1128ζ-IL12 CAR T cells had decreased levels of F4/80+ CD11b+MDSCs. Genetic analysis of recovered MDSCs from the ascites of treated animals showed skewing towards an M1-phenotype via upregulation of cytokines, chemokines, MHC-II, and downregulation of Arg1. Furthermore, clodronate-mediated depletion of TAM’s further enhanced survival in mice treated with 4H1128ζ-IL12 CAR T cells. Conclusions: These results demonstrate the mechanisms of efficacy of localized delivery of IL-12 to the tumor microenvironment by 4H1128ζ-IL12 CAR T cells.

Tumor specific regulatory T cells in the bone marrow of breast cancer patients selectively upregulate the emigration receptor S1P1

Regulatory T cells (Treg) hamper anti-tumor T-cell responses resulting in reduced survival and failure of cancer immunotherapy. Among lymphoid organs, the bone marrow (BM) is a major site of Treg residence and recirculation. However, the process governing the emigration of Treg from BM into the circulation remains elusive. We here show that breast cancer patients harbour reduced Treg frequencies in the BM as compared to healthy individuals or the blood. This was particularly the case for tumor antigen-specific Treg which were quantified by MHCII tumor peptide loaded tetramers. We further demonstrate that decreased Treg distribution in the BM correlated with increased Treg redistribution to tumor tissue, suggesting that TCR triggering induces a translocation of Treg from the BM into tumor tissue. Sphingosine-1-phosphate receptor 1 (S1P1)—which is known to mediate exit of immune cells from lymphoid organs was selectively expressed by tumor antigen-specific BM Treg. S1P1 expression could be induced in Treg by BM-resident antigen-presenting cells (BMAPCs) in conjunction with TCR stimulation, but not by TCR stimulation or BMAPCs alone and triggered the migration of Treg but not conventional T cells (Tcon) to its ligand Sphingosine-1-phosphate (S1P). Interestingly, we detected marked S1P gradients between PB and BM in breast cancer patients but not in healthy individuals. Taken together, our data suggest a role for S1P1 in mediating the selective mobilization of tumor specific Treg from the BM of breast cancer patients and their translocation into tumor tissue.

Food Oral Immunotherapy (FOIT) Failures: Who and Why

Food Oral Immunotherapy (FOIT) Failures: Who and Why

Redirecting the focus of cancer immunotherapy to premalignant conditions

Much progress has been made in introducing immunological treatment approaches for cancer, with lessons learned from both the successes and failures of immunotherapy. Among the challenges of immunotherapeutic approaches for cancer are the multitudes of mechanisms by which cancers are known to subvert the immune defenses. This has led to the incorporation into the immunotherapeutic arsenal strategies by which to overcome the cancer's immunological blockades. What has been only superficially explored is the immunological milieu of premalignant lesions and the possibility of immunological approaches for the treatment of premalignant lesions so as to prevent secondary premalignant lesions and their progression to cancer. This review discusses the immunological environment associated with premalignant lesions, and the possible missed opportunity of utilizing immunological treatment strategies in the less hostile environment of premalignant lesions as compared to the immune subversive cancer environment.

Complex Monitoring of Biochemical and Radionuclide Parameters in Patients with Metastatic Renal Cell Carcinoma during Immunotherapy.

Study Objective To study the effectiveness of complex monitoring of the kidney function, based on biochemical and radionuclide methods in patients with metastatic renal cell carcinoma (mRCC). Materials and Methods 41 mRCC patients after nephrectomy received nivolumab (n = 23) and interferon-α (n = 18) from 2015 to 2017. At baseline and 2 months after, all patients underwent blood chemistry, urinalysis, Rehberg test, and ELISA to determine serum levels of IL-17A, TGF-β, and erythropoietin. The monitoring of the renal function and urodynamics by complex renal scintigraphy (CRS) was used for all patients using a dual-detector gamma camera and simultaneous data recording in 2 projections. The interpretation of CRS data used the original SENS CRS technology. Study Results Statistically significant correlations were established between IL-17A, TGF-β, and D (excretion rate of 99mTc-technephore from the parenchyma) and Rnfsc (a stable sign of nephrosclerosis), respectively. A significant correlation was established between the parameters of the complex functional monitoring with the prognosis for the risk of renal failure (RF) and efficacy of immunotherapy in mRCC. Conclusions All mRCC patients after nephrectomy were recommended to undergo biochemical monitoring with inclusion of TGF-β and IL-17A, as well as radionuclide monitoring (CRS) to determine the RF risk at an early stage.