Sorafenib prevents escape from host immunity in liver cirrhosis patients with advanced hepatocellular carcinoma

The Usefulness of Serum Interleukin-6 as a Predictor of Response to Atezolizumab plus Bevacizumab Combination Treatment in Hepatocellular Carcinoma

INTRODUCTION

In atezolizumab plus bevacizumab (Atezo/Bev) combination treatment, both drugs act on the immune system. Previously, we reported that immunological changes after Atezo/Bev administration for unresectable hepatocellular carcinoma (uHCC) revealed significant alterations in interleukin (IL)-6, soluble IL-2 receptor, tumor necrosis factor-alpha, and programmed cell death-1 levels. Among these variable factors, serum levels of IL-6 can be easily measured on a commercial basis. Therefore, this study aimed to investigate the utility of serum IL-6 as a predictor of tumor response to Atezo/Bev treatment for uHCC.

METHOD

The study included 44 patients with HCC treated with Atezo/Bev. Blood samples were collected before and 3 weeks after treatment, and tumor response was assessed using contrast-enhanced computed tomography 6 weeks after treatment.

RESULTS

Significant changes in serum IL-6 levels were observed in patients treated with Atezo/Bev as first-line therapy but not in those treated with it as second-line or later-line therapy. In patients treated with Atezo/Bev as first-line therapy, serum IL-6 levels increased significantly after treatment in patients with a complete or partial response but not in patients with stable or progressive disease. Furthermore, compared to other tumor markers such as alpha-fetoprotein, Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein, and des-gamma-carboxyprothrombin, serum IL-6 levels exhibited the highest sensitivity in predicting tumor response during the treatment period.

CONCLUSION

In patients with uHCC treated with Atezo/Bev, serum IL-6 levels could serve as a potential predictor of tumor response. Elevated levels after treatment may indicate a favorable tumor response and prognosis.

Remaining Issues Related to Serum Cytokines in Patients with Unresectable Hepatocellular Carcinoma Treated by Atezolizumab plus Bevacizumab Combination Treatment

INTRODUCTION

Atezolizumab plus bevacizumab (AteBev) combination treatment is widely used as first-line systemic therapy for unresectable hepatocellular carcinoma (uHCC). We aimed to clarify therapeutic issues regarding serum cytokines and the immune reaction in patients with uHCC treated with AteBev.

METHODS

We analyzed preserved serum from a previous prospective study on adult Japanese patients with chronic liver disease and uHCC who received AteBev treatment at our hospital. In that study, AteBev was administered intravenously every 3 weeks, and blood samples were collected before and after 3 weeks' treatment. Dynamic computed tomography was performed after 6 weeks of treatment to assess response.

RESULTS

In the prospective study, 21 of the 59 patients showed partial response (PR) and 19 patients showed stable disease, but 19 patients showed progressive disease (PD). We found that serum levels of tumor necrosis factor-alpha, interleukin (IL)-6, and soluble IL-2 receptor (IL-2R) increased significantly in the PR group, but only soluble IL-2R increased significantly in the PD group. Regulatory T cells decreased significantly in the PD group, but there was no significant change in Th1 or Th2 cells from before to after treatment in any group. As regards soluble MHC-class I, pre-treatment levels were significantly lower in the PD group than in the PR group, and serum levels increased significantly with treatment in the PD group.

CONCLUSION

These findings reveal a need to further improve T-cell priming and to further make T cells recognize tumor antigens in uHCC.

Lenvatinib Might Induce Activation of Host Immunity in Patients with Hepatocellular Carcinoma

INTRODUCTION

Atezolizumab, an immune checkpoint inhibitor, plus bevacizumab, a monoclonal antibody that binds to vascular endothelial growth factor (VEGF), is an approved first-line systemic treatment for unresectable hepatocellular carcinoma (HCC). Immune checkpoint inhibitors are more effective in patients with HCC when administered with anti-VEGF drugs; however, these drugs affect host immunity. Lenvatinib is an anti-VEGF agent used to treat HCC; therefore, this study evaluated the effect of treatment of HCC with lenvatinib on host immunity in patients with chronic liver disease (CLD).

METHODS

We studied adult Japanese patients with CLD and unresectable HCC treated with lenvatinib at our hospital. Lenvatinib was administered for 4 weeks (8 mg/day for bodyweight <60 kg; 12 mg/day for bodyweight >60 kg). Blood samples were collected at baseline and at 4 weeks of treatment and examined for immune-related changes.

RESULTS

Forty-three patients were enrolled in this study. We found a significant increase in T helper (Th) 1 cells following 4 weeks of lenvatinib treatment, although there was no significant difference in Th2 cells and regulatory T cells. We also found a significant increase in serum levels of TNF-alpha, soluble TNF-alpha receptor I, and endothelial growth factor following 4 weeks of lenvatinib treatment. Furthermore, an increase in Th1 cells and serum levels of TNF-alpha was found in patients with partial response.

CONCLUSION

Lenvatinib might induce Th1-dominant host immunity in patients with CLD and unresectable HCC treatment in patients who showed a partial response. These changes in host immunity may be a biomarker in HCC patients treated with lenvatinib.

Immunoregulatory signal networks and tumor immune evasion mechanisms: insights into therapeutic targets and agents in clinical development

Through activation of immune cells, the immune system is responsible for identifying and destroying infected or otherwise damaged cells including tumorigenic cells that can be recognized as foreign, thus maintaining homeostasis. However, tumor cells have evolved several mechanisms to avoid immune cell detection and killing, resulting in tumor growth and progression. In the tumor microenvironment, tumor infiltrating immune cells are inactivated by soluble factors or tumor promoting conditions and lose their effects on tumor cells. Analysis of signaling and crosstalk between immune cells and tumor cells have helped us to understand in more detail the mechanisms of tumor immune evasion and this forms basis for drug development strategies in the area of cancer immunotherapy. In this review, we will summarize the dominant signaling networks involved in immune escape and describe the status of development of therapeutic strategies to target tumor immune evasion mechanisms with focus on how the tumor microenvironment interacts with T cells.

Well-Controlled Viremia Predicts the Outcome of Hepatocellular Carcinoma in Chronic Viral Hepatitis Patients Treated with Sorafenib

Simple Summary

Previous studies reported hepatitis C virus-related hepatocellular carcinoma (HCV-HCC) patients might have better prognosis than hepatitis B virus-related HCC (HBV-HCC) patients at using sorafenib. However, the information about status of viremia was limited in these studies. We defined well-controlled viremia as patients who had undetectable viremia, or who had been receiving antivirals at least six months before sorafenib. We reported 116 (65.2%) HBV-HCC patients and 62 (34.8%) HCV-HCC patients who received sorafenib, and progression-free survival and overall survival (OS) rates between these two groups were not different. Before sorafenib, 56% of HBV-HCC patients and 54.8% of HCV-HCC patients had well-controlled viremia and their OS was superior to those who had uncontrolled viremia (15.5 vs. 11.1 months, p = 0.001). Besides, well-controlled viremia was associated with mortality in multivariate analysis (Hazard ratio: 0.63, 95% confidence interval: 0.42–0.93, p = 0.022). The significance of our study is the first research to confirm the prognostic value of well-controlled viremia between HBV-HCC and HCV-HCC patients receiving sorafenib. Besides, HBV or HCV infection was not associated with the outcome, neither in univariate nor in multivariate analysis.

Abstract

Without analyzing the status of viremia, hepatitis C virus-related hepatocellular carcinoma (HCV-HCC) patients are proposed to have better prognosis than hepatitis B virus-related HCC (HBV-HCC) patients using sorafenib. We aimed to elucidate the efficacy of concurrent sorafenib and anti-viral treatment for HCC patients with HBV or HCV infection in real world. Between January 2018 and January 2021, 256 unresectable HCC patients receiving first-line sorafenib were evaluated. High-potency nucleoside analogs were used for HBV control, whereas direct-acting antivirals were administered for HCV eradication. Well-controlled viremia was defined as patients who had undetectable viremia, or who had been receiving antivirals at least 6 months before sorafenib. We recruited 116 (65.2%) HBV-HCC patients and 62 (34.8%) HCV-HCC patients. Using sorafenib, progression-free survival and overall survival (OS) rates between these two groups were not different. Before sorafenib, 56% of HBV-HCC patients and 54.8% of HCV-HCC patients had well-controlled viremia and their OS was superior to those who had uncontrolled viremia (15.5 vs. 11.1 months, p = 0.001). Dividing our patients into four subgroups as well-controlled HCV viremia, well-controlled HBV viremia, uncontrolled HCV viremia, and uncontrolled HBV viremia, their OS rates were distributed with a significantly decreasing trend as 21.9 months, 15.0 months, 14.2 months, and 5.7 months (p = 0.009). Furthermore, well-controlled viremia was associated with mortality in multivariate analysis (Hazard ratio: 0.63, 95% confidence interval: 0.42–0.93, p = 0.022). In real-life, HBV or HCV infection did not contribute to the prognosis of HCC patients receiving sorafenib; however, whether viremia was controlled or not did contribute.

Sorafenib use in hepatitis B virus- or hepatitis C virus-related hepatocellular carcinoma: A propensity score matching study

Sorafenib is the recommended first-line treatment option for patients with advanced hepatocellular carcinoma (HCC). Hepatitis C virus (HCV)-related advanced HCC (HCV-HCC) seemed to have a better response than hepatitis B virus (HBV)-related HCC (HBV-HCC) in sorafenib use, but it was undetermined. Hence, we aimed to investigate the effect of sorafenib between HBV-HCC and HCV-HCC patients in Taiwan. From August 2012 to December 2016, 575 consecutive advanced HCC patients received sorafenib under the reimbursement of Taiwan national health insurance in our hospital. Radiologic assessment was performed at a 2-month interval. Those patients with tumor progression or liver function deterioration were disallowed for further sorafenib use. Patients with HBV or HCV infection were, retrospectively, enrolled and followed till December 2018. There were 277 (62.4%) HBV-HCC patients and 167 (37.6%) HCV-HCC patients. Before sorafenib, 192 (69.3%) HBV-HCC patients who had used nucleoside analogs (NAs) for HBV management, whereas only 5 (3%) HCV-HCC patients received interferon-based antiviral therapy. Overall survival (OS) of HCV-HCC patients was significantly superior to HBV-HCC patients without NAs (8.8 months vs. 4.9 months, p = 0.006), but was noninferior to HBV-HCC patients with NAs (8.8 months vs. 10.7 months, p = 0.54). Using propensity score matching, progression-free survival (2.0 months vs. 2.1 months, p = 0.374) and OS (10.5 months vs. 9.6 months, p = 0.746) between HBV-HCC and HCV-HCC groups were not different. Antiviral therapy might increase survival benefits of advanced HBV-HCC patients underwent sorafenib use, leading to a comparable OS to HCV-HCC patients in Taiwan.

Direct and Indirect Modulation of T Cells by VEGF-A Counteracted by Anti-Angiogenic Treatment

Vascular endothelial growth factor A is known to play a central role in tumor angiogenesis. Several studies showed that VEGF-A is also an immunosuppressive factor. In tumor-bearing hosts, VEGF-A can modulate immune cells (DC, MDSC, TAM) to induce the accumulation of regulatory T-cells while simultaneously inhibiting T-cell functions. Furthermore, VEGFR-2 expression on activated T-cells and FoxP3^high regulatory T-cells also allow a direct effect of VEGF-A. Anti-angiogenic agents targeting VEGF-A/VEGFR contribute to limit tumor-induced immunosuppression. Based on interesting preclinical studies, many clinical trials have been conducted to investigate the efficacy of anti-VEGF-A/VEGFR treatments combined with immune checkpoint blockade leading to the approvement of these associations in different tumor locations. In this review, we focus on the impact of VEGF-A on immune cells especially regulatory and effector T-cells and different therapeutic strategies to restore an antitumor immunity.

Old Player-New Tricks: Non Angiogenic Effects of the VEGF/VEGFR Pathway in Cancer

Angiogenesis has long been considered to facilitate and sustain cancer growth, making the introduction of anti-angiogenic agents that disrupt the vascular endothelial growth factor/receptor (VEGF/VEGFR) pathway an important milestone at the beginning of the 21st century. Originally research on VEGF signaling focused on its survival and mitogenic effects towards endothelial cells, with moderate so far success of anti-angiogenic therapy. However, VEGF can have multiple effects on additional cell types including immune and tumor cells, by directly influencing and promoting tumor cell survival, proliferation and invasion and contributing to an immunosuppressive microenvironment. In this review, we summarize the effects of the VEGF/VEGFR pathway on non-endothelial cells and the resulting implications of anti-angiogenic agents that include direct inhibition of tumor cell growth and immunostimulatory functions. Finally, we present how previously unappreciated studies on VEGF biology, that have demonstrated immunomodulatory properties and tumor regression by disrupting the VEGF/VEGFR pathway, now provide the scientific basis for new combinational treatments of immunotherapy with anti-angiogenic agents.

The Prognosis of Hepatocellular Carcinoma Treated with Sorafenib in Combination with TACE

OBJECTIVE

Sorafenib have been shown to be effective in the treatment of advanced HCC and has been standard therapy since its release in Japan in 2009 (Llovet et al., 2008; Cheng et al., 2009). However, due to a low response rate, more aggressive combination treatment has been utilized as a multimodal strategy. The present study aimed to determine the efficacy of sorafenib alone and in combination with transarterial chemoembolization (TACE) for the treatment of advanced HCC.

METHODS

All patients with unresectable advanced HCC who were prescribed sorafenib at Kanto Rosai Hospital were included in the study. Five-year overall survival (OS) rates were estimated for patients treated with sorafenib alone or in combination with TACE. Multivariate and univariate regression analyses were performed to identify factors affecting OS. Analysis using propensity score matching and inverse-probability weights were also performed.

RESULTS

A total of 46 patients were treated with sorafenib up to June 2018. The total sorafenib dose administered was higher in the TACE combination group (70900 mg vs. 24000 mg vs. with sorafenib alone), although the relative dose intensity was lower (11.7% vs. 17.6%, respectively). The 5-year survival prognosis estimated using the Kaplan-Meier method was longer in patients treated with sorafenib in combination with TACE versus sorafenib alone (36.3% vs. 7.7%). Combination with TACE was the only factor associated with improved OS in both univariate and multivariate analysis. Among cases matched by propensity scores the hazard rate for combination with TACE was 0.067 (95% CI 0.091-1.128).

CONCLUSION

With an array of therapeutic options currently available, it is important to determine the efficacy of different multimodal strategies, such as sorafenib combined TACE, for patients with unresectable HCC.

Targeting tumour microenvironment by tyrosine kinase inhibitor

Tumour microenvironment (TME) is a key determinant of tumour growth and metastasis. TME could be very different for each type and location of tumour and TME may change constantly during tumour growth. Multiple counterparts in surrounding microenvironment including mesenchymal-, hematopoietic-originated cells as well as non-cellular components affect TME. Thus, therapeutics that can disrupt the tumour-favouring microenvironment should be further explored for cancer therapy. Previous efforts in unravelling the dysregulated mechanisms of TME components has identified numerous protein tyrosine kinases, while its corresponding inhibitors have demonstrated potent modulatory effect on TME. Recent works have demonstrated that beyond the direct action on cancer cells, tyrosine kinase inhibitors (TKIs) have been implicated in inactivation or normalization of dysregulated TME components leading to cancer regression. Either through re-sensitizing the tumour cells or reversing the immunological tolerance microenvironment, the emergence of these TME modulatory mechanism of TKIs supports the combinatory use of TKIs with current chemotherapy or immunotherapy for cancer therapy. Therefore, an appropriate understanding on TME modulation by TKIs may offer another mode of action of TKIs for cancer treatment. This review highlights mode of kinase activation or paracrine ligand production from TME components and summarises the findings on the potential use of various TKIs on regulating TME components. At last, the combination use of current TKIs with immunotherapy in the perspectives of efficacy and safety are discussed.

Immunomodulatory Activity of VEGF in Cancer

The ability of tumor cells to escape tumor immunosurveillance contributes to cancer development. Factors produced in the tumor microenvironment create "tolerizing" conditions and thereby help the tumor to evade antitumoral immune responses. VEGF-A, already known for its major role in tumor vessel growth (neoangiogenesis), was recently identified as a key factor in tumor-induced immunosuppression. In particular, VEGF-A fosters the proliferation of immunosuppressive cells, limits T-cell recruitment into tumors, and promotes T-cell exhaustion. Antiangiogenic therapies have shown significant efficacy in patients with a variety of solid tumors, preventing tumor progression by limiting tumor-induced angiogenesis. VEGF-targeting therapies have also been shown to modulate the tumor-induced immunosuppressive microenvironment, enhancing Th1-type T-cell responses and increasing tumor infiltration by T cells. The immunomodulatory properties of VEGF-targeting therapies open up new perspectives for cancer treatment, especially through strategies combining antiangiogenic drugs with immunotherapy. Preclinical models and early clinical studies of these combined approaches have given promising results.

A phase I study of high-dose interleukin-2 with sorafenib in patients with metastatic renal cell carcinoma and melanoma

This study was designed to evaluate the safety and feasibility of high-dose interleukin-2 (HD IL-2) followed by sorafenib in patients with metastatic melanoma (MM) and renal cell carcinoma (RCC). Biomarkers relevant to the antitumor effects of IL-2 that may be altered by sorafenib including the percentages of natural T-regulatory cells (Tregs), myeloid-derived suppressor cells (MDSC), and STAT5 phosphorylation (pSTAT5) in T cells were evaluated. We hypothesized that the proposed treatment schedule is feasible and safe and may lead to enhanced tumor response. A phase I dose escalation trial was conducted in patients with either metastatic RCC or MM. HD IL-2 (600,000 IU/kg IV q8h×8–12 doses) was administered on days 1–5 and 15–19, followed by sorafenib on days 29–82. The sorafenib dose was escalated. The percentage of Tregs, MDSC, and pSTAT5 in T cells were evaluated in peripheral blood by flow cytometry. Twelve of the 18 patients were evaluable for dose-limiting toxicity. No dose-limiting toxicity was observed. The treatment-related toxicity was predictable and did not seem to be additive with this schedule of administration. Partial responses were seen in 3 patients. No significant changes in the percentage of circulating Treg and MDSC were observed, whereas sorafenib did not adversely affect the ability of IL-2 to induce pSTAT5 in T cells. HD IL-2 followed by sorafenib was safe and feasible in patients with MM and RCC and did not adversely affect T-cell signaling through STAT5 in response to IL-2.

Hepatitis B virus reactivation in patients with hepatocellular carcinoma undergoing anti-cancer therapy

Patients with hepatocellular carcinoma (HCC) often experience hepatic morbidity. Hepatitis B virus (HBV) reactivation is well documented as a serious hepatic morbidity during anti-cancer therapy. Reported rates of HBV reactivation in chronic carriers with HCC undergoing chemotherapy range from 4%-67%. Apart from chemotherapy, HBV reactivation has been increasingly identified in settings of hepatectomy and local ablation therapies. The rates of HBV reactivation vary with different levels of immunosuppression and depend on treatment, viral factors, and patient characteristics. The principal concern relating to reactivation is that a substantial proportion of patients with reactivation suffer from liver dysfunction during therapy, which often leads to disruption of planned, potentially life-prolonging treatments, adversely affecting the patients' final outcome. The first step in the management of HBV reactivation is identification of patients at risk of reactivation by testing for HBV serology prior to commencing anti-cancer therapy. Although it is a serious complication, HBV reactivation is preventable with prophylactic anti-HBV drugs. Multiple publications have shown the benefit of prophylactic or preemptive antiviral therapy in this setting and justified such an approach before the start of therapy. Given the tumors and underlying cirrhosis, long-term use of antivirals with high potency and low risk of resistance is recommended in patients with HCC. This topic review will summarize the epidemiology, pathogenesis, and clinical issues related to HBV reactivation in HCC patients, and will discuss proper management against HBV reactivation during anti-cancer therapy for HCC.

Control of the immune response by pro-angiogenic factors

The progressive conversion of normal cells into cancer cells is characterized by the acquisition of eight hallmarks. Among these criteria, the capability of the cancer cell to avoid the immune destruction has been noted. Thus, tumors develop mechanisms to become invisible to the immune system, such as the induction of immunosuppressive cells, which are able to inhibit the development of an efficient immune response. Molecules produced in the tumor microenvironment are involved in the occurrence of an immunosuppressive microenvironment. Recently, it has been shown that vascular endothelial growth factor A (VEGF-A) exhibits immunosuppressive properties in addition to its pro-angiogenic activities. VEGF-A can induce the accumulation of immature dendritic cells, myeloid-derived suppressor cells, regulatory T cells, and inhibit the migration of T lymphocytes to the tumor. Other pro-angiogenic factors such as placental growth factor (PlGF) could also participate in tumor-induced immunosuppression, but only few works have been performed on this point. Here, we review the impact of pro-angiogenic factors (especially VEGF-A) on immune cells. Anti-angiogenic molecules, which target VEGF-A/VEGFR axis, have been developed in the last decades and are commonly used to treat cancer patients. These drugs have anti-angiogenic properties but can also counteract the tumor-induced immunosuppression. Based on these immunomodulatory properties, anti-angiogenic molecules could be efficiently associated with immunotherapeutic strategies in preclinical models. These combinations are currently under investigation in cancer patients.

Cancer-Induced Alterations of NK-Mediated Target Recognition: Current and Investigational Pharmacological Strategies Aiming at Restoring NK-Mediated Anti-Tumor Activity

Despite evidence of cancer immune-surveillance, which plays a key role in tumor rejection, cancer cells can escape immune recognition through different mechanisms. Thus, evasion to Natural killer (NK) cell-mediated anti-tumor activity is commonly described and is mediated by various mechanisms, mainly cancer cell-induced down-regulation of NK-activating receptors (NCRs, NKG2D, DNAM-1, and CD16) as well as up-regulation of inhibitory receptors (killer-cell immunoglobulin-like receptors, KIRs, NKG2A). Alterations of NK cells lead to an impaired recognition of tumor cells as well as a decreased ability to interact with immune cells. Alternatively, cancer cells downregulate expression of ligands for NK cell-activating receptors and up-regulate expression of the ligands for inhibitory receptors. A better knowledge of the extent and the mechanisms of these defects will allow developing pharmacological strategies to restore NK cell ability to recognize and lyse tumor cells. Combining conventional chemotherapy and immune modulation is a promising approach likely to improve clinical outcome in diverse neoplastic malignancies. Here, we overview experimental approaches as well as strategies already available in the clinics that restore NK cell functionality. Yet successful cancer therapies based on the manipulation of NK cell already have shown efficacy in the context of hematologic malignancies. Additionally, the ability of cytotoxic agents to increase susceptibility of tumors to NK cell lysis has been studied and may require improvement to maximize this effect. More recently, new strategies were developed to specifically restore NK cell phenotype or to stimulate NK cell functions. Overall, pharmacological immune modulation trends to be integrated in therapeutic strategies and should improve anti-tumor effects of conventional cancer therapy.

Spontaneous and therapeutic immune responses in hepatocellular carcinoma: implications for current and future immunotherapies

Hepatocellular carcinoma (HCC) represents a major health problem in the world, ranking fifth in incidence and third in cancer-related deaths. Due to the unique immunosuppressive microenvironment of the liver, HCC develops in an immunotolerant niche posing an important obstacle to immunotherapy. A number of studies, however, have shown immunogenic properties of HCC by demonstrating spontaneous adaptive immune responses during tumor formation and progression. Furthermore, studies examining immune responses during HCC therapy have revealed that conventional treatments such as surgical resection, locoregional therapy and systemic therapy with antibodies, small molecules or chemotherapy induce adaptive immune responses that contribute to therapeutic effects. These observations have provided a basis for clinical trials involving adoptive transfers of T cells or natural killer cells, peptide and dendritic cell vaccinations or, more recently, virotherapy and inhibition of co-inhibitory molecules. Here, spontaneous and therapeutic immune responses in HCC and their implication for current and future immunotherapies are discussed.

Hepatocellular carcinoma from an immunologic perspective

Hepatocellular carcinoma is the third most common cancer worldwide. It is an inflammation-associated cancer. Multiple investigators have demonstrated that analysis of the tumor microenvironment may be used to predict patient outcome, indicating the importance of local immune responses in this disease. In contrast with other types of cancer, in which surgery, radiation, and systemic cytotoxic chemotherapies dominate the treatment options, in hepatocellular carcinoma locoregional treatments are widely applied. Such treatments induce rapid tumor cell death and antitumor immune responses, which may favor or impair the patients' outcome. Recent immunotherapeutic studies demonstrating promising results include trials evaluating intratumoral injection of an oncolytic virus expressing granulocyte macrophage colony-stimulating factor, glypican-3 targeting treatments, and anti-CTLA4 treatment. Although some of these novel approaches may provide benefit as single agents, there is a clear opportunity in hepatocellular carcinoma to evaluate these in combination with the standard modalities to more effectively harness the immune response.

Changes of cytokines in patients with liver cirrhosis and advanced hepatocellular carcinoma treated by sorafenib

PURPOSE

Recently, the oral multikinase inhibitor sorafenib has been used to treat advanced hepatocellular carcinoma (aHCC). Tumor necrosis factor (TNF) induces apoptosis of tumor cells by binding to TNF-related apoptosis-inducing ligand, while binding of the Fas ligand on cytotoxic T lymphocytes to the Fas receptor on hepatocytes also causes apoptosis. The aim of this study was to retrospectively evaluate changes of cytokines in patients with liver cirrhosis (LC) and aHCC receiving sorafenib therapy.

METHODS

Fifty-seven adult Japanese LC patients received sorafenib for aHCC (200-800 mg/day for 4 weeks) between 2009 and 2012 at our hospital. Blood samples were collected in the early morning before and after treatment, and the serum levels of soluble TNF-alpha (sTNF-alpha), soluble TNF receptor (sTNF-R), soluble Fas ligand (sFas L), and soluble Fas (sFas) were evaluated.

RESULTS

Ten patients were treated with sorafenib at 200 mg/day (200 mg group), 37 patients were given 400 mg/day (400 mg group), and 10 patients received 800 mg/day (800 mg group). The serum level of sTNF-alpha was significantly increased after treatment compared with before treatment in the 400 and 800 mg groups. The serum level of sTNF-R also showed a significant increase after treatment in the 400 mg group, although there was no significant difference of sTNF-R between before and after treatment in the 200 and 800 mg groups. sFas showed a significant decrease after treatment compared with before treatment in the 400 and 800 mg groups, although the serum level of sFas L never exceeded 0.15 ng/ml.

CONCLUSIONS

These findings suggest that treatment with sorafenib at doses ≥400 mg/day might promote TNF-related or Fas-related apoptosis by increasing the circulating level of TNF-alpha or decreasing that of sFas.

Sorafenib relieves cell-intrinsic and cell-extrinsic inhibitions of effector T cells in tumor microenvironment to augment antitumor immunity

Sorafenib, a multitargeted antiangiogenic tyrosine kinase inhibitor, is the standard of care for patients with advanced hepatocellular carcinoma (HCC). Cumulating evidence suggests that sorafenib differentially affects immune cells; however, whether this immunomodulatory effect has any impact on antitumor immune responses is unknown. Using an orthotopic mouse model of HCC and tumor-free mice, we investigated the effects of sorafenib on antitumor immunity and characterized the underlying mechanisms. Sorafenib treatment inhibited tumor growth and augmented antitumor immune responses in mice bearing established orthotopic HCC. The tumor-specific effector T cell functions were upregulated, while the proportion of PD-1-expressing CD8(+) T cells and regulatory T cells (Tregs) was reduced in tumor microenvironment of sorafenib-treated mice. Mechanistically, the sorafenib-mediated effects on Tregs could be independent of its direct tumor-suppressing activities. Sorafenib treatment reduced Treg numbers by inhibiting their proliferation and inducing apoptosis. Moreover, sorafenib inhibited the function of Tregs, characterized by diminished expression of Treg-associated molecules important for their function and by their impaired suppressive capacity. These data reveal that sorafenib treatment enhanced functions of tumor-specific effector T cells as well as relieved PD-1-mediated intrinsic and Treg-mediated non-cell-autonomous inhibitions in tumor microenvironment leading to effective antitumor immune responses. In addition to the well-known tumor-inhibiting activity of sorafenib, its enhancement of antitumor immunity may also contribute to the clinical efficacy. Our findings uncover a previously unrecognized mechanism of action of sorafenib and indicate that sorafenib represents a potential targeted agent suitable to be combined with immunotherapeutic approaches to treat cancer patients.

A clinical trial of CTLA-4 blockade with tremelimumab in patients with hepatocellular carcinoma and chronic hepatitis C

BACKGROUND & AIMS

Tremelimumab is a monoclonal antibody that blocks cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), an inhibitory co-receptor that interferes with T cell activation and proliferation. The purpose of this pilot clinical trial was to test the antitumor and antiviral effect of tremelimumab in patients with hepatocellular carcinoma (HCC) and chronic hepatitis C virus (HCV) infection; and to study the safety of its administration to cirrhotic patients.

METHODS

Tremelimumab at a dose of 15 mg/kg IV every 90 days was administered until tumor progression or severe toxicity. Twenty patients were assessable for toxicity and viral response and 17 were assessable for tumor response. Most patients were in the advanced stage and 43% had an altered liver function (Child-Pugh class B).

RESULTS

A good safety profile was recorded and no patient needed steroids because of severe immune-mediated adverse events. Some patients had a transient albeit intense elevation of transaminases after the first dose, but not following subsequent cycles. Partial response rate was 17.6% and disease control rate was 76.4%. Time to progression was 6.48 months (95% CI 3.95-9.14). A significant drop in viral load was observed while new emerging variants of the hypervariable region 1 of HCV replaced the predominant variants present before therapy, particularly in those patients with a more prominent drop in viral load. This antiviral effect was associated with an enhanced specific anti-HCV immune response.

CONCLUSIONS

Tremelimumab safety profile and antitumor and antiviral activity, in patients with advanced HCC developed on HCV-induced liver cirrhosis, support further investigation.

Changes in peripheral blood immune cells: their prognostic significance in metastatic renal cell carcinoma patients treated with molecular targeted therapy

Recently, novel molecular targeted agents markedly changed the treatment of renal cell carcinoma (RCC), with promising results. However, there is little understanding of how these agents affect immune cell populations in RCC, an immunogenic tumor. Therefore, we investigated the changes in the peripheral blood immune cells in 58 RCC patients during the first 4 weeks of treatment with sorafenib, sunitinib, everolimus, or temsirolimus and evaluated whether these changes were associated with clinical outcomes. The immunological parameters were the proportion of type-1 (Th1) and type-2 (Th2) T cells, regulatory T cells (Treg), mature dendritic cells, and the neutrophil-to-lymphocyte ratio (NLR). The changes in these immune cells varied with the agents and the clinical response, dichotomized by the median progression-free survival (PFS) time (PFS-short or PFS-long). A significant decrease in the Th1/Th2 ratio was seen after sunitinib treatment only in the PFS-short group, suggesting a shift toward Th2 that down-regulates host immunity. The NLRs indicative of the balance between host immunity and cancer-related inflammation were consistently lower in the PFS-long group than in the PFS-short group, suggesting that lower NLR is associated with better clinical response. Only sunitinib decreased NLR remarkably regardless of PFS status, which may favor anti-tumor immunity. When patients were dichotomized by the cutoff values, Th1/Th2 ratio was not associated with PFS in any targeted therapy, while lower pre-treatment NLR was associated with longer PFS in each targeted therapy. In addition, in RCC patients given sequential targeted therapy, those with a lower baseline NLR survived significantly longer compared with the counterparts. Moreover, those whose baseline NLR was sustained low during the initial therapy survived the longest. Our results suggest the diverse changes in host immune cells in RCC patients during targeted therapy. The changes in NLR during the early phase of targeted therapy may be a powerful discriminator of who will benefit from the subsequent treatment.

Modulation of immunity by antiangiogenic molecules in cancer

In the last decades a new class of therapeutic drugs have been developed that block tumor angiogenesis. These antiangiogenic molecules, which target VEGF or VEGFR, PDGFR, and c-kit, can act not only on endothelial cells but also on immune cells. Some antiangiogenic molecules inhibit the development of immunosuppressive mechanisms developed by the tumors to escape the immune system (such as regulatory T cells, myeloid-derived suppressor cells, and immunosuppressive cytokines). These immunomodulatory effects must be characterized in detail to enable a better prescription of these treatments. In this paper we will focus on the impact of anti-angiogenic drugs on immunosuppression and their potential combination with immunotherapeutic strategies. Interestingly, immune parameters or their modulation during treatment could serve as potential biomarkers of response or resistance to anti-angiogenic therapies.

Tumor-infiltrating regulatory T cells: phenotype, role, mechanism of expansion in situ and clinical significance

In immunocompetent individuals, the immune system initially eradicates potentially tumorigenic cells as they develop, a capacity that is progressively lost when malignant cells acquire alterations that sustain immunosubversion and/or immunoevasion. One of the major mechanisms whereby cancer cells block antitumor immune responses involves a specific class of immunosuppressive T cells that-in the vast majority of cases-express the Forkhead box P3 (FOXP3) transcription factor. Such FOXP3(+) regulatory T cells (Tregs) accumulate within neoplastic lesions as a result of several distinct mechanisms, including increased infiltration, local expansion, survival advantage and in situ development from conventional CD4(+) cells. The prognostic/predictive significance of tumor infiltration by Tregs remains a matter of debate. Indeed, high levels of intratumoral Tregs have been associated with poor disease outcome in cohorts of patients affected by multiple, but not all, tumor types. This apparent discrepancy may relate to the existence of functionally distinct Treg subsets, to the fact that Tregs near-to-invariably infiltrate neoplastic lesions together with other cells from the immune system, notably CD4(+) and CD8(+) T lymphocytes and/or to peculiar features of some oncogenic programs that involve a prominent pro-inflammatory component. In this review, we will discuss the phenotype, function and clinical significance of various Treg subsets.