Phase II clinical trial of sorafenib plus interferon-alpha treatment for patients with metastatic renal cell carcinoma in Japan

Targeting inflammation as cancer therapy

Inflammation has accompanied human beings since the emergence of wounds and infections. In the past decades, numerous efforts have been undertaken to explore the potential role of inflammation in cancer, from tumor development, invasion, and metastasis to the resistance of tumors to treatment. Inflammation-targeted agents not only demonstrate the potential to suppress cancer development, but also to improve the efficacy of other therapeutic modalities. In this review, we describe the highly dynamic and complex inflammatory tumor microenvironment, with discussion on key inflammation mediators in cancer including inflammatory cells, inflammatory cytokines, and their downstream intracellular pathways. In addition, we especially address the role of inflammation in cancer development and highlight the action mechanisms of inflammation-targeted therapies in antitumor response. Finally, we summarize the results from both preclinical and clinical studies up to date to illustrate the translation potential of inflammation-targeted therapies.

New frontiers against sorafenib resistance in renal cell carcinoma: From molecular mechanisms to predictive biomarkers

Renal cell carcinoma (RCC) is a highly vascularized tumor and prone to distant metastasis. Sorafenib is the first targeted multikinase inhibitor and first-line chemical drug approved for RCC therapy. In fact, only a small number of RCC patients benefit significantly from sorafenib treatment, while the growing prevalence of sorafenib resistance has become a major obstacle for drug therapy effectivity of sorafenib. The molecular mechanisms of sorafenib resistance in RCC are not completely understood by now. Herein, we comprehensively summarize the underlying mechanisms of sorafenib resistance and molecular biomarkers for predicting sorafenib responsiveness. Moreover, we outline strategies suitable for overcoming sorafenib resistance and prospect potential approaches for identifying biomarkers associated with sorafenib resistance in RCC, which contributes to guide individualized and precision drug therapy.

IFN-α facilitates the effect of sorafenib via shifting the M2-like polarization of TAM in hepatocellular carcinoma

Tumor-associated macrophages (TAMs) and how they are activated play critical roles in tumor progression and metastasis, and in hepatocellular carcinoma (HCC), they are associated with sorafenib resistance. Reprogramming of TAMs into M1-like macrophages has been proposed as an approach to stimulate tumor regression. Here we studied the collective effects of interferon-alpha (IFN-α) and sorafenib on HCC. We found that IFN-α delayed tumor growth and inhibited pulmonary metastasis in an orthotopic HCC implantation model. Via in vitro studies, we found that IFN-α treatment could reprogram M2-like RAW264.7 and THP-1 macrophage cells toward M1-like cells. In addition, we also found that IFN-α combined with a low dose of sorafenib has a synergistic inhibitory effect on HCC tumor growth and pulmonary metastasis without obvious toxicity in an in vivo mice model. Moreover, IFN-α increased sorafenib's therapeutic efficacy by shifting TAM polarization to an M1-like phenotype, increasing and activating intratumoral CD8⁺ T cells in HCCs. In conclusion, a combination of IFN-α and sorafenib have synergistic inhibitory effects on HCC growth and metastasis resulting from a shift in TAM polarization rather than their depletion. Our study supports the future clinical use of a combination of IFN-α and sorafenib for the treatment of advanced HCC.

Interferon-induced IFIT5 promotes epithelial-to-mesenchymal transition leading to renal cancer invasion

Interferon is known as a pleiotropic factor in innate immunity, cancer immunity and therapy. Despite an objective short-term response of interferon (IFN) therapy in renal cell carcinoma (RCC) patients, the potential adverse effect of IFN on RCC cells is not fully understood. In this study, we demonstrate that IFNs can enhance RCC invasion via a new mechanism of IFIT5-mediated tumor suppressor microRNA (miRNA) degradation resulted in the elevation of Slug and ZEB1 and epithelial-to-mesenchymal transition (EMT). Clinically, a significant upregulation of IFNγ signaling pathway (such as IFNGR1, IFNGR2, STAT1 and STAT2) is observed in RCC patients with metastatic disease. Overall, this study provides a new mechanism of action of IFN-elicited canonical pathway in regulating suppressor miRNAs. Most importantly, it highlights the potential pro-metastatic effect of IFNs, which could undermine the clinical applicability of IFNs for treating RCC patients.

Modern approaches to kidney cancer immunotherapy

Kidney cancer is a heterogeneous group of malignant tumors that develop from cells of the proximal convoluted tubules of the kidney. In Russia renal cell carcinoma holds the 2nd place after prostate cancer among tumors of genitourinary system. The main method of renal cell carcinoma treatment is radical nephrectomy, at the same time, high resistance of kidney cancer to chemotherapy and a weak response to hormone treatment are noted, and the effectiveness of cytokine therapy (interleukin 2, interferon alfa) does not exceed 18–20 %. The introduction into clinical practice of modern immune system affecting drugs has changed the disease prognosis for many patients with various malignant neoplasms. Currently, active development of immunotherapeutic drugs directed against inhibitory receptors of T-cells, the so-called “immunity control points” takes place, the most studied among these drugs are anti-CTLA-4 (cytotoxic T-lymphocyte associated protein 4) and anti-PD-1 (рrogrammed cell death pathway 1)/PD-L1 (programmed death ligand 1) monoclonal antibodies. In this review a detailed description of the PD-1 receptor and its PD-L1 ligand, as well as the prognostic and predictive significance of their expression in various types of renal cell carcinoma and the role in suppressing the antitumor T-cell immune response are presented. Blockade of PD-1/PD-L1 enhances antitumor immunity reducing the amount and/or immunosuppressive activity of regulatory T-cells (suppressors) and restoring the activity of effector T-cells that leads to an enhancement of the antitumor immune response. The blockade of PD-1 also stimulates proliferation of memory B-cells. In this regard, drugs that suppress the function of PD-1 are now widely used in the treatment of cancer including kidney cancer. The authors provide a list of promising drugs acting on PD-1/PD-L1 system used in renal cell carcinoma: nivolumab, pembrolizumab and some others. The results of clinical studies se of immunotherapeutic drugs in kidney cancer are analyzed.

Inhibition of the AKT/mTOR Pathway Augments the Anticancer Effects of Sorafenib in Thyroid Cancer

BACKGROUND

Sorafenib is a multikinase inhibitor that has been approved for the treatment of patients with advanced ¹³¹iodine (¹³¹I) refractory differentiated thyroid cancer (DTC). However, the progression-free survival of patients with advanced ¹³¹I refractory DTC is short, and most DTC patients eventually acquire resistance to sorafenib. Therefore, new therapeutic strategies need to be developed.

MATERIALS AND METHODS

The thyroid cancer cell lines 8505C and FTC133 were treated with sorafenib in the presence or absence of BEZ235 or small interfering RNA (siRNA) directed against AKT. A CCK8 kit was used to evaluate cell viability. Protein expression levels of relevant genes were determined by Western blotting analysis, whereas messenger RNA expression levels were determined by real-time PCR analysis. Flow cytometry was performed to assess the number of apoptotic cells.

RESULTS

The results indicate that sorafenib simultaneously inhibited the activities of the MAPK and PI3K/AKT/mTOR pathways in thyroid cancer cells. Treatment of 8505C and FTC133 cells with NVP-BEZ235, siRNA against AKT, or sorafenib induced tumor cell apoptosis and led to reduced tumor cell proliferation. Sorafenib in combination with PI3K/AKT/mTOR inhibition by NVP-BEZ235 or AKT siRNA enhanced apoptosis and proliferation suppression.

CONCLUSIONS

The evidence of this study suggests that a combinatorial approach that inhibits both the MAPK and PI3K/AKT/mTOR pathways exerts a greater antitumor effect than sorafenib alone in thyroid cancer cell lines.

Overall survival of first-line axitinib in metastatic renal cell carcinoma: Japanese subgroup analysis from phase II study

Subgroup analyses of a randomized global phase II study of axitinib showed objective response rate of 66% and median progression-free survival of 27.6 months in treatment-naïve Japanese patients with metastatic renal cell carcinoma (RCC). This analysis evaluated overall survival (OS) and safety in 44 Japanese patients and compared the results with 169 non-Japanese patients. In addition, baseline characteristics for predictive factors that may influence OS in first-line metastatic RCC were explored in all patients using a Cox proportional hazard model. With median follow-up of 33 months, fewer than half (16 of 44) of the Japanese patients had died and median OS was not reached (95% confidence interval [CI], 38.8 months-not estimable), whereas 107 of 169 (63%) non-Japanese patients had died and median OS was 33.9 months (95% CI, 28.9-42.7). Estimated 1-year, 2-year and 3-year survival probability (95% CI) was 86.4% (76.2-96.5), 75.0% (62.2-87.8) and 68.2% (54.4-81.9), respectively, in Japanese patients, and was higher than that in non-Japanese patients (75.1% [68.4-81.8], 62.1% [54.5-69.7] and 47.2% [39.3-55.1], respectively). The updated safety analysis did not reveal any new adverse events of concern among Japanese or non-Japanese patients. The multivariate analysis identified that lower baseline Eastern Cooperative Oncology Group performance status, lower baseline tumor burden, and longer time from histopathological diagnosis to treatment were significant positive predictors of OS. The current analysis confirmed the clinical activity of axitinib in treatment-naïve Japanese patients with metastatic RCC, with an acceptable toxicity profile.

Increased serum level of soluble interleukin-2 receptor is associated with a worse response of metastatic clear cell renal cell carcinoma to interferon alpha and sequential VEGF-targeting therapy

BACKGROUND

Renal cell carcinoma (RCC) is a tumor with immunogenic properties. Soluble interleukin-2 receptor (sIL-2R) has a role in T cell activation and may be important for immune regulation in various conditions, including infections, transplantation rejection, autoimmune inflammatory states, and cancer. We investigated the prognostic value of the serum sIL-2R level in patients with metastatic RCC receiving IFN-alpha and vascular endothelial growth factor (VEGF)-targeting therapy.

METHODS

We monitored the serum level of sIL-2R over time and examined phosphorylated Akt expression by the primary tumor in 47 patients with metastatic clear cell RCC (ccRCC) undergoing cytoreductive nephrectomy followed by first-line adjuvant therapy with IFN-alpha plus sequential VEGF-targeting therapy as second- or third-line adjuvant therapy.

RESULTS

A preoperative increase of the serum level of sIL-2R was correlated with a higher preoperative serum level of programmed cell death 1 (PD-1)-ligand 1 (PD-L1), increased expression of phosphorylated Akt by the primary tumor, and a worse response to IFN-alpha/sequential VEGF-targeting therapy, as well as being an independent prognostic factor for a shorter overall survival time by multivariate analysis. Over time, the serum sIL-2R level largely reflected the tumor response to therapy.

CONCLUSIONS

Monitoring the serum level of sIL-2R may help to predict the biological behavior of ccRCC, its response to IFN-alpha/sequential VEGF-targeting therapy, and the prognosis.

The Essential Role of Type I Interferons in Differentiation and Activation of Tumor-Associated Neutrophils

Type I interferons (IFNs) were first characterized in the process of viral interference. However, since then, IFNs are found to be involved in a wide range of biological processes. In the mouse, type I IFNs comprise a large family of cytokines. At least 12 IFN-α and one IFN-β can be found and they all signal through the same receptor (IFNAR). A hierarchy of expression has been established for type I IFNs, where IFN-β is induced first and it activates in a paracrine and autocrine fashion a cascade of other type I IFNs. Besides its importance in the induction of the IFN cascade, IFN-β is also constitutively expressed in low amounts under normal non-inflammatory conditions, thus facilitating "primed" state of the immune system. In the context of cancer, type I IFNs show strong antitumor function as they play a key role in mounting antitumor immune responses through the modulation of neutrophil differentiation, activation, and migration. Owing to their plasticity, neutrophils play diverse roles during cancer development and metastasis since they possess both tumor-promoting (N2) and tumor-limiting (N1) properties. Notably, the differentiation into antitumor phenotype is strongly supported by type I IFNs. It could also be shown that these cytokines are critical for the suppression of neutrophil migration into tumor and metastasis site by regulating chemokine receptors, e.g., CXCR2 on these cells and by influencing their longevity. Type I IFNs limit the life span of neutrophils by influencing both, the extrinsic as well as the intrinsic apoptosis pathways. Such antitumor neutrophils efficiently suppress the pro-angiogenic factors expression, e.g., vascular endothelial growth factor and matrix metallopeptidase 9. This in turn restricts tumor vascularization and growth. Thus, type I IFNs appear to be the part of the natural tumor surveillance mechanism. Here we provide an up to date review of how type I IFNs influence the pro- and antitumor properties of neutrophils. Understanding these mechanisms is particularly important from a therapeutic point of view.

Trial Watch-Immunostimulation with cytokines in cancer therapy

During the past decade, great efforts have been dedicated to the development of clinically relevant interventions that would trigger potent (and hence potentially curative) anticancer immune responses. Indeed, developing neoplasms normally establish local and systemic immunosuppressive networks that inhibit tumor-targeting immune effector cells, be them natural or elicited by (immuno)therapy. One possible approach to boost anticancer immunity consists in the (generally systemic) administration of recombinant immunostimulatory cytokines. In a limited number of oncological indications, immunostimulatory cytokines mediate clinical activity as standalone immunotherapeutic interventions. Most often, however, immunostimulatory cytokines are employed as immunological adjuvants, i.e., to unleash the immunogenic potential of other immunotherapeutic agents, like tumor-targeting vaccines and checkpoint blockers. Here, we discuss recent preclinical and clinical advances in the use of some cytokines as immunostimulatory agents in oncological indications.