Sex Differences In Immune Checkpoint Therapy

Women seem to do better than men in immune checkpoint therapy for cancer.  Studying such differences may help devise improved therapeutic approaches for all patients.  Thus - “The pooled overall survival HR was 0·72 (95% CI 0·65-0·79) in male patients treated with immune checkpoint inhibitors, compared with men treated in control groups. In women treated with immune checkpoint inhibitors, the pooled overall survival HR compared with control groups was 0·86 (95% CI 0·79-0·93). The difference in efficacy between men and women treated with immune checkpoint inhibitors was significant (p=0·0019).’

Wnt Signaling And Angiogenesis

Blocking angiogenesis to prevent tumors from getting their blood supply is an important therapeutic approach; Wnt signaling is involved.  Abstract:

Angiogenesis is a normal biological process wherein new blood vessels form from the growth of pre-existing blood vessels. Preventing angiogenesis in solid tumours by targeting pro-angiogenic factors including vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1), basic fibroblast growth factor (bFGF), hepatocyte growth factor, and platelet-derived growth factor (PDGF) is currently under investigation for cancer treatment. Concurrently targeting the cell signalling pathways involved in the transcriptional and post-translational regulation of these factors may provide positive therapeutic results. One such pathway is the Wnt signalling pathway. Wnt was first discovered in mice infected with mouse mammary tumour virus, and has been crucial in improving our understanding of oncogenesis and development. In this review, we summarise molecular and cellular aspects of the importance of Wnt signalling to angiogenesis, including β-catenin-dependent mechanisms of angiogenic promotion, as well as the study of Wnt antagonists, such as the secreted frizzled-related protein family (SFRPs) which have been shown to inhibit angiogenesis. The growing understanding of the underlying complexity of the biochemical pathways mediating angiogenesis is critical to the identification of new molecular targets for therapeutic applications.

An Anti-Cancer Antibiotic

An antibiotic, Nigericin, has anti-cancer activity, and one mechanism is through targeted suppression of Wnt signaling.  Abstract:

Nigericin, an antibiotic derived from Streptomyces hygroscopicus that works by acting as an H+, K+ and Pb2+ ionophore, has exhibited promising anticancer activity. The main purpose of this study is to investigate its inhibitory effects on Wnt/β-catenin signaling pathway in colorectal cancer (CRC) cells and clarify the underlying mechanism. We exposed two CRC lines (SW620 and KM12) to increasing concentrations of nigericin for different time periods and the 50% inhibiting concentration (IC50) values were evaluated. Our data showed that nigericin treatment significantly reduced tumor cell proliferation in dose- and time-dependent manners in CRC cells. The subsequent experiments in vitro and in vivo implied that nigericin could significantly suppress the tumor growth, migration and invasion, and induce the apoptosis of CRC cells. Our results of western blot and immunofluorescence assay showed that nigericin could suppress the Wnt/β-catenin signaling pathway in CRC cells with dose-dependent increased expressions of downstream effectors and target proteins. To further elucidate the inhibitory effects of nigericin via a β-catenin-dependent signaling mechanism, we established the stably β-catenin over-expression CRC cells. Western blot, SuperTOPflash luciferase reporter and immunoprecipitation assays all confirmed β-catenin as a critical intermediary and player in Wnt/β-catenin pathway, and nigericin exerted anti-cancer effects on CRC cells by directly targeting the β-catenin destruction complex. These results suggested that Wnt/β-catenin signaling might have an essential role in CRC progression. Nigericin targeting Wnt/β-catenin signaling might provide new insight into the molecular mechanism of nigericin towards cancer cells, and suggest possible clinical application in CRC

Wnt Inhibitor And Small Cell Lung Cancer

A Wnt signaling inhibitor has some activity against small cell lung cancer.  Abstract:

Small cell lung cancer (SCLC) is the most aggressive type of lung cancer due to a fast tumor doubling time and early hematogenous spread. Advances in the treatment of non-small cell lung cancer using targeted therapies having been made, but no targeted drugs for SCLC have been approved. The Wnt signaling pathway is associated with tumor progression and metastasis; therefore, the inhibition of Wnt/β-catenin signaling is a strategy for anticancer drugs. Tankyrase 1 (TNKS1) is overexpressed in a number of types of cancer and XAV939 is a small molecule inhibitor of TNKS1 which may inhibit tumor growth. The present study aimed to investigate the potential molecular mechanisms underlying XAV939-induced suppression of the viability of SCLC cells. MTT assays were used to determine the viability-inhibition rate of cells and to identify the drug concentration which optimally inhibited cell viability. Flow cytometry was used to determine whether XAV939 induced apoptosis of SCLC cells, and to analyze the effect of the drug on the cell cycle. The results of the present study identified that XAV939 inhibited the viability of NCI-H446 cells in a dose-dependent manner, but cisplatin inhibited NCI-H446 cell viability in a time- and dose-dependent manner. The combination of XAV939 and cisplatin exhibited a slightly more pronounced inhibition of cell viability at an increased dose of XAV939. In addition, XAV939 markedly induced cell apoptosis of the SCLC cell line H446 by increasing the proportion of cells in the G0/G1 phase, leading to inhibition of the cell cycle. The results of the present study indicated that XAV939 inhibited the viability of the NCI-H446 SCLC cell line by inducing cell apoptosis through the Wnt signaling pathway. Therefore, XAV939 may be useful for the treatment of SCLC.

Protein Glycosylation Targeting Immunotherapy

Another approach for anti-cancer immunotherapy, abstract:

Protein glycosylation provides proteomic diversity in regulating protein localization, stability, and activity; it remains largely unknown whether the sugar moiety contributes to immunosuppression. In the study of immune receptor glycosylation, we showed that EGF induces programmed death ligand 1 (PD-L1) and receptor programmed cell death protein 1 (PD-1) interaction, requiring β-1,3-N-acetylglucosaminyl transferase (B3GNT3) expression in triple-negative breast cancer. Downregulation of B3GNT3 enhances cytotoxic T cell-mediated anti-tumor immunity. A monoclonal antibody targeting glycosylated PD-L1 (gPD-L1) blocks PD-L1/PD-1 interaction and promotes PD-L1 internalization and degradation. In addition to immune reactivation, drug-conjugated gPD-L1 antibody induces a potent cell-killing effect as well as a bystander-killing effect on adjacent cancer cells lacking PD-L1 expression without any detectable toxicity. Our work suggests targeting protein glycosylation as a potential strategy to enhance immune checkpoint therapy.

New Melanoma Therapy

New therapeutic approach for melanoma described here.  Abstract:

Development of an effective treatment against advanced tumors remains a major challenge for cancer immunotherapy. Approximately 50% of human melanoma is driven by B-Raf proto-oncogene mutation (BRAF-mutant). Tumors with such mutation are desmoplastic, highly immunosuppressive, and often resistant to immune checkpoint therapies. We have shown that immunotherapy mediated by low dose doxorubicin-induced immunogenic cell death was only partially effective for this type of tumor, and not effective in long-term inhibition of tumor progression. Wnt family member 5A (Wnt5a), a signaling protein highly-produced by BRAF-mutant melanoma cells, has been implicated in inducing dendritic cell tolerance and tumor fibrosis, thus hindering effective antigen presentation and T cell infiltration. We hypothesized that Wnt5a is a key molecule controlling the immunosuppressive tumor microenvironment in metastatic melanoma. Accordingly, we have designed and generated a trimeric trap protein, containing the extracellular domain of Fizzled 7 receptor that binds Wnt5a with a Kd ~278 nM. Plasmid DNA encoding for the Wnt5a trap was delivered to the tumor by using cationic lipid-protamine-DNA (LPD) nanoparticles. Expression of Wnt5a trap in the tumor, although transient, was greater than in that of any other major organs including liver, resulting in a significant reduction of the Wnt5a level in the tumor microenvironment without systematic toxicity. Significantly, combination of Wnt5a trapping and low dose doxorubicin showed great tumor growth inhibition and host survival prolongation. Our findings indicated that efficient local Wnt5a trapping significantly remodeled the immunosuppressive tumor microenvironment to facilitate immunogenic cell death-mediated.

Resistance to Cancer Immune Therapy: TNF Signaling

Resistance to cancer immune therapy seems to involve downregulation of tumor necrosis factor (TNF) signaling, which possibly in the future can be a focal point of new therapies to make immune-based treatment more effective.  Abstract:

Immunotherapy has revolutionized outcomes for cancer patients, but the mechanisms of resistance remain poorly defined. We used a series of whole-genome clustered regularly interspaced short palindromic repeat (CRISPR)-based screens performed in vitro and in vivo to identify mechanisms of tumor immune evasion from cytotoxic lymphocytes [CD8+ T cells and natural killer (NK) cells]. Deletion of key genes within the tumor necrosis factor (TNF) signaling, interferon-γ (IFN-γ) signaling, and antigen presentation pathways provided protection of tumor cells from CD8+ T cell-mediated killing and blunted antitumor immune responses in vivo. Deletion of a number of genes in the TNF pathway also emerged as the key mechanism of immune evasion from primary NK cells. Our screens also identified that the metabolic protein 2-aminoethanethiol dioxygenase (Ado) modulates sensitivity to TNF-mediated killing by cytotoxic lymphocytes and is required for optimal control of tumors in vivo. Remarkably, we found that tumors delete the same genes when exposed to perforin-deficient CD8+ T cells, demonstrating that the dominant immune evasion strategy used by tumor cells is acquired resistance to T cell-derived cytokine-mediated antitumor effects. We demonstrate that TNF-mediated bystander killing is a potent T cell effector mechanism capable of killing antigen-negative tumor cells. In addition to highlighting the importance of TNF in CD8+ T cell- and NK cell-mediated killing of tumor cells, our study also provides a comprehensive picture of the roles of the TNF, IFN, and antigen presentation pathways in immune-mediated tumor surveillance.

The Circadian Clock And Cancer Therapy

The circadian clock, that controls many cellular activities in a ‘timed” fashion, affects cancer and tumor development; hence targeting the clock can be a novel cancer therapeutic approach.  Some nuclear hormone receptors are important components of the circadian clock; agonists (activators) of these receptors have specific anti-cancer activity, which is an important and encouraging finding and can lead to innovative therapies.  Abstract:

The circadian clock imposes daily rhythms in cell proliferation, metabolism, inflammation and DNA damage response. Perturbations of these processes are hallmarks of cancer and chronic circadian rhythm disruption predisposes individuals to tumour development. This raises the hypothesis that pharmacological modulation of the circadian machinery may be an effective therapeutic strategy for combating cancer. REV-ERBs, the nuclear hormone receptors REV-ERBα (also known as NR1D1) and REV-ERBβ (also known as NR1D2), are essential components of the circadian clock. Here we show that two agonists of REV-ERBs-SR9009 and SR9011-are specifically lethal to cancer cells and oncogene-induced senescent cells, including melanocytic naevi, and have no effect on the viability of normal cells or tissues. The anticancer activity of SR9009 and SR9011 affects a number of oncogenic drivers (such as HRAS, BRAF, PIK3CA and others) and persists in the absence of p53 and under hypoxic conditions. The regulation of autophagy and de novo lipogenesis by SR9009 and SR9011 has a critical role in evoking an apoptotic response in malignant cells. Notably, the selective anticancer properties of these REV-ERB agonists impair glioblastoma growth in vivo and improve survival without causing overt toxicity in mice. These results indicate that pharmacological modulation of circadian regulators is an effective antitumour strategy, identifying a class of anticancer agents with a wide therapeutic window. We propose that REV-ERB agonists are inhibitors of autophagy and de novo lipogenesis, with selective activity towards malignant and benign neoplasms.

Targeting KRAS Mutations

Targeting KRAS mutant cancers; mutations of KRAS are frequent in many forms of cancer therefore this is an excellent therapeutic strategy.  Abstract:

KRASG12C was recently identified to be potentially druggable by allele-specific covalent targeting of Cys-12 in vicinity to an inducible allosteric switch II pocket (S-IIP). Success of this approach requires active cycling of KRASG12C between its active-GTP and inactive-GDP conformations as accessibility of the S-IIP is restricted only to the GDP-bound state. This strategy proved feasible for inhibiting mutant KRAS in vitro; however, it is uncertain whether this approach would translate to in vivo. Here, we describe structure-based design and identification of ARS-1620, a covalent compound with high potency and selectivity for KRASG12C. ARS-1620 achieves rapid and sustained in vivo target occupancy to induce tumor regression. We use ARS-1620 to dissect oncogenic KRAS dependency and demonstrate that monolayer culture formats significantly underestimate KRAS dependency in vivo. This study provides in vivo evidence that mutant KRAS can be selectively targeted and reveals ARS-1620 as representing a new generation of KRASG12C-specific inhibitors with promising therapeutic potential.

Rimonabant And Colorectal Cancer

Targeted killing of neoplastic colon cells; abstract:

Colorectal cancer (CRC), like other tumor types, is a highly heterogeneous disease. Within the tumor bulk, intra-tumoral heterogeneity is also ascribable to Cancer Stem Cells (CSCs) subpopulation, characterized by high chemoresistance and the unique ability to retain tumorigenic potential, thus associated to tumor recurrence. High dynamic plasticity of CSCs, makes the development of winning therapeutic strategies even more complex to completely eradicate tumor fuel. Rimonabant, originally synthesized as antagonist/inverse agonist of Cannabinoid Receptor 1, is able to inactivate Wnt signaling, both in vitro and in vivo, in CRC models, through inhibition of p300-histone acetyltransferase activity. Since Wnt/β-Catenin pathway is the main player underlying CSCs dynamic, this finding candidates Rimonabant as potential modulator of cancer stemness, in CRC. In this work, using established 3D cultures of primary colon CSCs, taking into account the tumor heterogeneity through monitoring of Wnt activity, we demonstrated that Rimonabant was able to reduces both tumor differentiated cells and colon CSCs proliferation and to control their survival in long term cultures. Interestingly, in ex vivo model of wild type human organoids, retaining both architecture and heterogeneity of original tissue, Rimonabant showed no toxicity against cells from healthy colon epithelium, suggesting its potential selectivity toward cancer cells. Overall, results from this work provided new insights on anti-tumor efficacy of Rimonabant, strongly suggesting that it could be a novel lead compound for CRC treatment.

Protecting Normal Intestinal Cells From Chemotherapy: PUMA

How to spare normal intestinal cells in chemotherapy. Interfering with the p53-PUMA axis by repressing PUMA can protect the normal cells while leaving p53-mediated killing of cancer cells intact.  This presumably is for p53 wild-type cells.  Many cancers lose p53 expression and for those this would likely be irrelevant.  Abstract:

The gastrointestinal (GI) epithelium is the fastest renewing adult tissue and is maintained by tissue-specific stem cells. Treatment-induced GI side effects are a major dose-limiting factor for chemotherapy and abdominal radiotherapy and can decrease the quality of life in cancer patients and survivors. p53 is a key regulator of the DNA damage response, and its activation results in stimulus- and cell type-specific outcomes via distinct effectors. We demonstrate that p53-dependent PUMA induction mediates chemotherapy-induced intestinal injury in mice. Genetic ablation of Puma, but not of p53, protects against chemotherapy-induced lethal GI injury. Blocking chemotherapy-induced loss of LGR5+ stem cells by Puma KO or a small-molecule PUMA inhibitor (PUMAi) prevents perturbation of the stem cell niche, rapid activation of WNT and NOTCH signaling, and stem cell exhaustion during repeated exposures. PUMAi also protects human and mouse colonic organoids against chemotherapy-induced apoptosis and damage but does not protect cancer cells in vitro or in vivo. Therefore, targeting PUMA is a promising strategy for normal intestinal chemoprotection because it selectively blocks p53-dependent stem cell loss but leaves p53-dependent protective effects intact.

Endocrine Therapy And Breast Cancer Recurrence

Endocrine therapy is typically used to prevent recurrent in breast cancer survivors, but it usually ended after five years because of side effects. A study has shown that recurrence rates steadily climb after cessation of such therapy, but that recurrence is also associated with the nodal status of the original cancer.  Abstract:

BACKGROUND:

The administration of endocrine therapy for 5 years substantially reduces recurrence rates during and after treatment in women with early-stage, estrogen-receptor (ER)-positive breast cancer. Extending such therapy beyond 5 years offers further protection but has additional side effects. Obtaining data on the absolute risk of subsequent distant recurrence if therapy stops at 5 years could help determine whether to extend treatment.

METHODS:

In this meta-analysis of the results of 88 trials involving 62,923 women with ER-positive breast cancer who were disease-free after 5 years of scheduled endocrine therapy, we used Kaplan-Meier and Cox regression analyses, stratified according to trial and treatment, to assess the associations of tumor diameter and nodal status (TN), tumor grade, and other factors with patients' outcomes during the period from 5 to 20 years.

RESULTS:

Breast-cancer recurrences occurred at a steady rate throughout the study period from 5 to 20 years. The risk of distant recurrence was strongly correlated with the original TN status. Among the patients with stage T1 disease, the risk of distant recurrence was 13% with no nodal involvement (T1N0), 20% with one to three nodes involved (T1N1-3), and 34% with four to nine nodes involved (T1N4-9); among those with stage T2 disease, the risks were 19% with T2N0, 26% with T2N1-3, and 41% with T2N4-9. The risk of death from breast cancer was similarly dependent on TN status, but the risk of contralateral breast cancer was not. Given the TN status, the factors of tumor grade (available in 43,590 patients) and Ki-67 status (available in 7692 patients), which are strongly correlated with each other, were of only moderate independent predictive value for distant recurrence, but the status regarding the progesterone receptor (in 54,115 patients) and human epidermal growth factor receptor type 2 (HER2) (in 15,418 patients in trials with no use of trastuzumab) was not predictive. During the study period from 5 to 20 years, the absolute risk of distant recurrence among patients with T1N0 breast cancer was 10% for low-grade disease, 13% for moderate-grade disease, and 17% for high-grade disease; the corresponding risks of any recurrence or a contralateral breast cancer were 17%, 22%, and 26%, respectively.

CONCLUSIONS:

After 5 years of adjuvant endocrine therapy, breast-cancer recurrences continued to occur steadily throughout the study period from 5 to 20 years. The risk of distant recurrence was strongly correlated with the original TN status, with risks ranging from 10 to 41%, depending on TN status and tumor grade. (Funded by Cancer Research UK and others.).

Epigenetic Cancer Therapy

Possible epigenetic-based cancer therapy for tumors with certain mutations; abstract:

The lysine methyltransferase KMT2C (also known as MLL3), a subunit of the COMPASS complex, implements monomethylation of Lys4 on histone H3 (H3K4) at gene enhancers. KMT2C (hereafter referred to as MLL3) frequently incurs point mutations across a range of human tumor types, but precisely how these lesions alter MLL3 function and contribute to oncogenesis is unclear. Here we report a cancer mutational hotspot in MLL3 within the region encoding its plant homeodomain (PHD) repeats and demonstrate that this domain mediates association of MLL3 with the histone H2A deubiquitinase and tumor suppressor BAP1. Cancer-associated mutations in the sequence encoding the MLL3 PHD repeats disrupt the interaction between MLL3 and BAP1 and correlate with poor patient survival. Cancer cells that had PHD-associated MLL3 mutations or lacked BAP1 showed reduced recruitment of MLL3 and the H3K27 demethylase KDM6A (also known as UTX) to gene enhancers. As a result, inhibition of the H3K27 methyltransferase activity of the Polycomb repressive complex 2 (PRC2) in tumor cells harboring BAP1 or MLL3 mutations restored normal gene expression patterns and impaired cell proliferation in vivo. This study provides mechanistic insight into the oncogenic effects of PHD-associated mutations in MLL3 and suggests that restoration of a balanced state of Polycomb-COMPASS activity may have therapeutic efficacy in tumors that bear mutations in the genes encoding these epigenetic factors.

Organoids In Cancer Research

Tumor organoids are an increasingly useful research tool in our quest to understand cancer development and to develop anti-cancer therapeutics.  Abstract:

The recent advances in in vitro 3D culture technologies, such as organoids, have opened new avenues for the development of novel, more physiological human cancer models. Such preclinical models are essential for more efficient translation of basic cancer research into novel treatment regimens for patients with cancer. Wild-type organoids can be grown from embryonic and adult stem cells and display self-organizing capacities, phenocopying essential aspects of the organs they are derived from. Genetic modification of organoids allows disease modelling in a setting that approaches the physiological environment. Additionally, organoids can be grown with high efficiency from patient-derived healthy and tumour tissues, potentially enabling patient-specific drug testing and the development of individualized treatment regimens. In this Review, we evaluate tumour organoid protocols and how they can be utilized as an alternative model for cancer research.

Chemotherapy Conundrum

Chemotherapy is usually effective against cancer, but recurrence/resistance can occur.  Senescence – stopping of cell cycle and cell growth – is typically considered good for malignant cancer cells, stop them from dividing as a therapy.  But here we see that chemotherapy-induced senescence changes cancer cells so that if they are released from senescence and re-enter cell cycle growth, they are more dangerous than before – with more stem cell like properties and more aggressive growth.  This needs to be addressed.  Abstract:

Cellular senescence is a stress-responsive cell-cycle arrest program that terminates the further expansion of (pre-)malignant cells. Key signalling components of the senescence machinery, such as p16INK4a, p21CIP1 and p53, as well as trimethylation of lysine 9 at histone H3 (H3K9me3), also operate as critical regulators of stem-cell functions (which are collectively termed 'stemness'). In cancer cells, a gain of stemness may have profound implications for tumour aggressiveness and clinical outcome. Here we investigated whether chemotherapy-induced senescence could change stem-cell-related properties of malignant cells. Gene expression and functional analyses comparing senescent and non-senescent B-cell lymphomas from Eμ-Myc transgenic mice revealed substantial upregulation of an adult tissue stem-cell signature, activated Wnt signalling, and distinct stem-cell markers in senescence. Using genetically switchable models of senescence targeting H3K9me3 or p53 to mimic spontaneous escape from the arrested condition, we found that cells released from senescence re-entered the cell cycle with strongly enhanced and Wnt-dependent clonogenic growth potential compared to virtually identical populations that had been equally exposed to chemotherapy but had never been senescent. In vivo, these previously senescent cells presented with a much higher tumour initiation potential. Notably, the temporary enforcement of senescence in p53-regulatable models of acute lymphoblastic leukaemia and acute myeloid leukaemia was found to reprogram non-stem bulk leukaemia cells into self-renewing, leukaemia-initiating stem cells. Our data, which are further supported by consistent results in human cancer cell lines and primary samples of human haematological malignancies, reveal that senescence-associated stemness is an unexpected, cell-autonomous feature that exerts its detrimental, highly aggressive growth potential upon escape from cell-cycle blockade, and is enriched in relapse tumours. These findings have profound implications for cancer therapy, and provide new mechanistic insights into the plasticity of cancer cells

DNA Nanorobots Against Cancer

DNA nanorobots against cancer.

From article:

DNA nanorobots are a somewhat new concept for drug delivery. They work by getting programmed DNA to fold into itself like origami and then deploying it like a tiny machine, ready for action.

DNA nanorobots, Nature Biotechnology 2018

The scientists behind this study tested the delivery bots by injecting them into mice with human breast cancer tumors. Within 48 hours, the bots had successfully grabbed onto vascular cells at the tumor sites, causing blood clots in the tumor's vessels and cutting off their blood supply, leading to their death.

Remarkably, the bots did not cause clotting in other parts of the body, just the cancerous cells they'd been programmed to target, according to the paper.

The scientists were also able to demonstrate the bots did not cause clotting in the healthy tissues of Bama miniature pigs, calming fears over what might happen in larger animals.

Engineering Immunotherapy

Engineering T cells to overcome tumor immune resistance- a possibly useful clinical strategy.  Abstract:

Purpose Transforming growth factor-β (TGF-β) production in the tumor microenvironment is a potent and ubiquitous tumor immune evasion mechanism that inhibits the expansion and function of tumor-directed responses; therefore, we conducted a clinical study to discover the effects of the forced expression of a dominant-negative TGF-β receptor type 2 (DNRII) on the safety, survival, and activity of infused tumor-directed T cells. Materials and Methods In a dose escalation study, eight patients with Epstein Barr virus-positive Hodgkin lymphoma received two to 12 doses of between 2 × 107 and 1.5 × 108 cells/m2 of DNRII-expressing T cells with specificity for the Epstein Barr virus-derived tumor antigens, latent membrane protein (LMP)-1 and LMP-2 (DNRII-LSTs). Lymphodepleting chemotherapy was not used before infusion. Results DNRII-LSTs were resistant to otherwise inhibitory concentrations of TGF-β in vitro and retained their tumor antigen-specific activity. After infusion, the signal from transgenic T cells in peripheral blood increased up to 100-fold as measured by quantitative polymerase chain reaction for the transgene, with a corresponding increase in the frequency of functional LMP-specific T cells. Expansion was not associated with any acute or long-term toxicity. DNRII-LSTs persisted for up to ≥ 4 years. Four of the seven evaluable patients with active disease achieved clinical responses that were complete and ongoing in two patients at > 4 years, including in one patient who achieved only a partial response to unmodified tumor-directed T cells. Conclusion TGF-β-resistant tumor-specific T cells safely expand and persist in patients with Hodgkin lymphoma without lymphodepleting chemotherapy before infusion. DNRII-LSTs can induce complete responses even in patients with resistant disease. Expression of DNRII may be useful for the many other tumors that exploit this potent immune evasion mechanism.

HIF Repression Cancer Therapy

Hypoxia – lack of oxygen – promotes the expression of  hypoxia-inducible factors that mediate cancer progression, including angiogenesis (blood vessel formation) that helps bring oxygen to the tumors.  Blocking those factors is a new form of therapy, described here.  Abstract:

Purpose The von Hippel-Lindau tumor suppressor is inactivated in the majority of clear cell renal cell carcinomas (ccRCCs), leading to inappropriate stabilization of hypoxia-inducible factor-2α (HIF-2α). PT2385 is a first-in-class HIF-2α antagonist. Objectives of this first-in-human study were to characterize the safety, pharmacokinetics, pharmacodynamics, and efficacy, and to identify the recommended phase II dose (RP2D) of PT2385. Patients and Methods Eligible patients had locally advanced or metastatic ccRCC that had progressed during one or more prior regimens that included a vascular endothelial growth factor inhibitor. PT2385 was administered orally at twice-per-day doses of 100 to 1,800 mg, according to a 3 + 3 dose-escalation design, followed by an expansion phase at the RP2D. Results The dose-escalation and expansion phases enrolled 26 and 25 patients, respectively. Patients were heavily pretreated, with a median of four (range, one to seven) prior therapies. No dose-limiting toxicity was observed at any dose. On the basis of safety, pharmacokinetic, and pharmacodynamic profiling, the RP2D was defined as 800 mg twice per day. PT2385 was well tolerated, with anemia (grade 1 to 2, 35%; grade 3, 10%), peripheral edema (grade 1 to 2, 37%; grade 3, 2%), and fatigue (grade 1 to 2, 37%; no grade 3 or 4) being the most common treatment-emergent adverse events. No patients discontinued treatment because of adverse events. Complete response, partial response, and stable disease as best response were achieved by 2%, 12%, and 52% of patients, respectively. At data cutoff, eight patients remained in the study, with 13 patients in the study for ≥ 1 year. Conclusion PT2385 has a favorable safety profile and is active in patients with heavily pretreated ccRCC, validating direct HIF-2α antagonism for the treatment of patients with ccRCC

Expanding The Immunotherapy Arsenal

A review on cancer immunotherapy is here, including the interesting approach of viruses that target and destroy tumor cells. Abstract:

Malignant cells have the capacity to rapidly grow exponentially and spread in part by suppressing, evading, and exploiting the host immune system. Immunotherapy is a form of oncologic treatment directed towards enhancing the host immune system against cancer. In recent years, manipulation of immune checkpoints or pathways has emerged as an important and effective form of immunotherapy. Agents that target cytotoxic T lymphocyte-associated molecule-4 (CTLA-4), programmed cell death receptor-1 (PD-1), and programmed cell death ligand-1 (PD-L1) are the most widely studied and recognized. Immunotherapy, however, extends beyond immune checkpoint therapy by using new molecules such as chimeric monoclonal antibodies and antibody drug conjugates that target malignant cells and promote their destruction. Genetically modified T cells expressing chimeric antigen receptors are able to recognize specific antigens on cancer cells and subsequently activate the immune system. Native or genetically modified viruses with oncolytic activity are of great interest as, besides destroying malignant cells, they can increase anti-tumor activity in response to the release of new antigens and danger signals as a result of infection and tumor cell lysis. Vaccines are also being explored, either in the form of autologous or allogenic tumor peptide antigens, genetically modified dendritic cells that express tumor peptides, or even in the use of RNA, DNA, bacteria, or virus as vectors of specific tumor markers. Most of these agents are yet under development, but they promise to be important options to boost the host immune system to control and eliminate malignancy. In this review, we have provided detailed discussion of different forms of immunotherapy agents other than checkpoint-modifying drugs. The specific focus of this manuscript is to include first-in-human phase I and phase I/II clinical trials intended to allow the identification of those drugs that most likely will continue to develop and possibly join the immunotherapeutic arsenal in a near future.

Localized Immunotherapy

Localized immunotherapy – injecting the agents directly into the tumor – has shown promise in studies.  Remarkably, if two tumors of the same origin are in different parts of the body – presumably in a mouse model – injecting in one of the tumors is sufficient to target the other one as well.  This would seem to have considerable therapeutic potential.  Abstract:

It has recently become apparent that the immune system can cure cancer. In some of these strategies, the antigen targets are preidentified and therapies are custom-made against these targets. In others, antibodies are used to remove the brakes of the immune system, allowing preexisting T cells to attack cancer cells. We have used another noncustomized approach called in situ vaccination. Immunoenhancing agents are injected locally into one site of tumor, thereby triggering a T cell immune response locally that then attacks cancer throughout the body. We have used a screening strategy in which the same syngeneic tumor is implanted at two separate sites in the body. One tumor is then injected with the test agents, and the resulting immune response is detected by the regression of the distant, untreated tumor. Using this assay, the combination of unmethylated CG-enriched oligodeoxynucleotide (CpG)-a Toll-like receptor 9 (TLR9) ligand-and anti-OX40 antibody provided the most impressive results. TLRs are components of the innate immune system that recognize molecular patterns on pathogens. Low doses of CpG injected into a tumor induce the expression of OX40 on CD4+ T cells in the microenvironment in mouse or human tumors. An agonistic anti-OX40 antibody can then trigger a T cell immune response, which is specific to the antigens of the injected tumor. Remarkably, this combination of a TLR ligand and an anti-OX40 antibody can cure multiple types of cancer and prevent spontaneous genetically driven cancers.