Sunitinib reverses type-1 immune suppression and decreases T-regulatory cells in renal cell carcinoma patients

Different immunological effects of the molecular targeted agents sunitinib, everolimus and temsirolimus in patients with renal cell carcinoma

Treatment with molecular targeted agents together with immune checkpoint inhibitors will most likely improve the efficacy of current cancer immunotherapy. Because molecular targeted agents not only directly affect cancer cells, but also influence immune cells and modulate the tumor microenvironment, a better understanding of the overall immunological effects of these drugs will contribute to the rational design of combination therapies. Therefore, this study performed extensive immune monitoring of patients' peripheral blood mononuclear cells (PBMCs) to investigate the immunological effects of the molecular targeted agents sunitinib, everolimus and temsirolimus, which have been widely used for the treatment of renal cell carcinoma (RCC). Immunophenotyping and functional analysis of PBMCs revealed that these molecular targeted agents exerted different immunological effects on patients with RCC. Sunitinib decreased the percentage of early‑stage myeloid‑derived suppressor cells (eMDSCs) and increased natural killer cells, but did not affect the phenotypes and effector functions of CD4+ or CD8+ T cells. Everolimus decreased effector regulatory T cells, but also decreased IL‑2‑producing CD4+ T cells and increased dysfunctional CD8+ T cells. Conversely, temsirolimus decreased programmed cell death protein 1+CD8+ T cells and eMDSCs, but increased interferon‑γ and tumor necrosis factor‑α double producers at the same time as decreasing dysfunctional CD8+ T cells, albeit not significantly. In conclusion, although everolimus and temsirolimus are mTOR inhibitors, their effects on overall T‑cell functions are very different. Therefore, although it may increase the risk of immune‑related toxicity, temsirolimus is expected to offer the best outcome when combined with other immunomodulators for the development of cancer immunotherapy.

Immune checkpoint inhibitors: The linchpins of modern immunotherapy

Immune checkpoint inhibitors (ICIs) have revolutionized our approach to cancer treatment in the past decade. While monoclonal antibodies to CTLA-4 and PD-1/PD-L1 have produced remarkable and durable responses in a subset of patients, the majority of patients will still develop primary or adaptive resistance. With complex mechanisms of resistance limiting the efficacy of checkpoint inhibitor monotherapy, it is critical to develop combination approaches to allow more patients to benefit from immunotherapy. In this review, I approach the current landscape of ICI research from the perspective of sarcomas, a rare group of bone and soft tissue cancers that have had limited benefit from checkpoint inhibitor monotherapy, and little investigation of biomarkers to predict responses. By surveying the various mechanisms of resistance and treatment modalities being explored in other solid tumors, I outline how ICIs will undoubtedly serve as the critical foundation for future directions in modern immunotherapy.

Integrating context of tumor biology and vaccine design to shape multidimensional immunotherapies

Advances in cancer therapy have offered great promise but only modest clinical benefits as monotherapies to date. Patients usually respond well to therapies targeted at specific mutations, but only for a short time. Conversely, immunotherapies help fewer patients, but increase survival. Combination therapies, which could offer the best of both worlds, are currently limited by substantial toxicity. While recent advances in genomics and proteomics have yielded an unprecedented depth of enabling datasets, it has also shifted the focus toward  in silico predictions. Designing the next wave of multidimensional immunotherapies will require leveraging this knowledge while providing a renewed emphasis on tumor biology and vaccine design. This includes careful selection of tumor clinical stage in the context of pre-existing tumor microenvironments, target antigen and technology platform selections to maximize their effect, and treatment staging. Here, we review strategies on how to approach an increasingly complex landscape of immunotherapeutic agents for use in combination therapies.

The challenges of adoptive cell transfer in the treatment of human renal cell carcinoma

Renal cell carcinoma (RCC) is one of the most lethal urologic malignancies. Its incidence continues to rise worldwide with a rate of 2% per year. Approximately, one-third of the RCC patients are diagnosed at advanced stages due to the asymptomatic nature of its early stages. This represents a great hurdle, since RCC is largely chemoresistant/radioresistant, and targeted therapy of mRCC still has limited efficacy. The 5-year survival rate of metastatic RCC (mRCC) is only around 10%. Adoptive cell transfer (ACT), a particular form of cell-based anticancer immunotherapy, is a promising approach in the treatment of mRCC. The vaccination principle, however, faces unique challenges that preclude the efficacy of ACT. In this article, we review the main challenges of ACT in the treatment of mRCC and describe multiple methods that can be used to overcome these challenges. In this respect, the ultimate purpose of this review is to provide a descriptive tool by which to improve the development of novel protocols for ACT of mRCC.

Efficacy and tolerability of anti-programmed death-ligand 1 (PD-L1) antibody (Avelumab) treatment in advanced thymoma

Background

Thymic epithelial tumors are PD-L1–expressing tumors of thymic epithelial origin characterized by varying degrees of lymphocytic infiltration and a predisposition towards development of paraneoplastic autoimmunity. PD-1–targeting antibodies have been evaluated, largely in patients with thymic carcinoma. We sought to evaluate the efficacy and safety of the anti-PD-L1 antibody, avelumab (MSB0010718C), in patients with relapsed, advanced thymic epithelial tumors and conduct correlative immunological studies.

Methods

Seven patients with thymoma and one patient with thymic carcinoma were enrolled in a phase I, dose-escalation trial of avelumab (MSB0010718C), and treated with avelumab at doses of 10 mg/kg to 20 mg/kg every 2 weeks until disease progression or development of intolerable side effects. Tissue and blood immunological analyses were conducted.

Results

Two of seven (29%) patients with thymoma had a confirmed Response Evaluation Criteria in Solid Tumors–defined partial response, two (29%) had an unconfirmed partial response and three patients (two thymoma; one thymic carcinoma) had stable disease (43%). Three of four responses were observed after a single dose of avelumab. All responders developed immune-related adverse events that resolved with immunosuppressive therapy. Only one of four patients without a clinical response developed immune-related adverse events. Responders had a higher absolute lymphocyte count, lower frequencies of B cells, regulatory T cells, conventional dendritic cells, and natural killer cells prior to therapy.

Conclusion

These results demonstrate anti-tumor activity of PD-L1 inhibition in patients with relapsed thymoma accompanied by a high frequency of immune-related adverse events. Pre-treatment immune cell subset populations differ between responders and non-responders.

Trial registration

ClinicalTrials.gov - NCT01772004. Date of registration – January 21, 2013.

Electronic supplementary material

The online version of this article (10.1186/s40425-019-0723-9) contains supplementary material, which is available to authorized users.

Profiles of tumor-infiltrating immune cells in renal cell carcinoma and their clinical implications

Tumor-infiltrating immune cells (TIICs) are crucial for the clinical outcome of renal cell carcinoma (RCC), as they regulate cancer progression. TIICs have therefore the potential to become novel targets of immunotherapies. The present study used CIBERSORT analytical tool, which is a deconvolution algorithm, to comprehensively analyze the composition of immune cells in RCC and normal tissues from The Cancer Genome Atlas (TCGA) cohort, and to determine the prognostic value of TIICs in RCC. A landscape of infiltrating immune cells was determined as containing 13 subpopulations of immune cells, with significant differences between normal and tumor tissues. Subsequently, Kaplan-Meier analysis and log-rank test were used to estimate the prognostic value of TIICs in RCC. The results demonstrated that a higher proportion of regulatory T cells (Tregs) [hazard ratio (HR)=1.596; 95% confidence interval (CI), 1.147–2.222; P=0.006] and follicular helper T cells (HR=1.516; 95% CI, 1.089–2.111; P=0.014) were associated with poor outcome in patients with RCC. Conversely, resting mast cells (HR=0.678; 95% CI, 0.487–0.943; P=0.021) and monocytes (HR=0.701; 95% CI, 0.503–0.977; P=0.036) were associated with a favorable prognosis in patients with RCC. Furthermore, the results from multivariate Cox regression analysis indicated that Tregs and monocytes represented independent risk factors for prognosis in patients with RCC. These findings demonstrated that gene profiling deconvolution by CIBERSORT served to determine the composition of immune cells infiltrated in RCC and may provide some crucial information for the development of immunotherapies.

Tumor Microenvironment Dynamics in Clear-Cell Renal Cell Carcinoma

Renal cell carcinoma stands out as one of the most immune-infiltrated tumors in pan-cancer comparisons. Features of the tumor microenvironment heavily affect disease biology and may affect responses to systemic therapy. With evolving frontline options in the metastatic setting, several immune checkpoint blockade regimens have emerged as efficacious, and there is growing interest in characterizing features of tumor biology that can reproducibly prognosticate patients and/or predict the likelihood of their deriving therapeutic benefit. Herein, we review pertinent characteristics of the tumor microenvironment with dedicated attention to candidate prognostic and predictive signatures as well as possible targets for future drug development. SIGNIFICANCE: Tumor microenvironment features broadly characterizing angiogenesis and inflammatory signatures have shown striking differences in response to immune checkpoint blockade and antiangiogenic agents. Integration of stromal and immune biomarkers may hence produce predictive and prognostic signatures to guide management with existing regimens as well as future drug development.

Prospect of immunotherapy combined with anti-angiogenic agents in patients with advanced non-small cell lung cancer

In the latest years, some drugs have been approved by European Medicines Agency (EMA) and/or the US Food and Drug Administration (FDA) for the treatment of patients with advanced non-small cell lung cancer (NSCLC), particularly for the treatment of those who have no targeted gene mutations or who have progressed on previously targeted therapy or platinum-containing dual-agent chemotherapy. In general, these drugs fall into two categories: anti-angiogenic agents and immune checkpoint inhibitors (ICIs). Anti-angiogenic agents currently approved by the FDA and/or EMA for advanced NSCLC treatment include bevacizumab, nintedanib, and ramucirumab. Anlotinib has been approved in advanced NSCLC by Chinese Food and Drug Administration (CFDA). These anti-angiogenic agents can induce anti-angiogenesis by targeting vascular endothelial growth factor (VEGF)/VEGF2 or inhibiting multiple small molecules involved in angiogenic and proliferative pathways such as platelet-derived growth factor receptors (PDGFRs) and fibroblast growth factor receptors (FGFRs). Although these drugs show significant therapeutic efficacy, most patients inevitably experience disease progression resulting in death. ICIs approved by the FDA and/or EMA for advanced NSCLC treatment include nivolumab, pembrolizumab, and atezolizumab. These ICIs can significantly improve efficacy compared with standard chemotherapy by targeting programmed cell death protein 1 (PD-1) receptor or PD-2 receptor with longer response duration and acceptable toxicity. However, the response rate of ICIs is suboptimal, and only a few patients ultimately benefit from immunotherapy. So current efforts have focused on exploring new potential combinatorial strategies with synergistic antitumor activity. Here, we summarized the theoretical basis, current clinical data, and potential future perspective of immunotherapy combined with anti-angiogenic agents for advanced NSCLC.

Ramucirumab plus pembrolizumab in patients with previously treated advanced non-small-cell lung cancer, gastro-oesophageal cancer, or urothelial carcinomas (JVDF): a multicohort, non-randomised, open-label, phase 1a/b trial

BACKGROUND

Pre-clinical and clinical evidence suggests that simultaneous blockade of VEGF receptor-2 (VEGFR-2) and PD-1 or PD-L1 enhances antigen-specific T-cell migration, antitumour activity, and has favourable toxicity. In this study, we aimed to assess the safety and preliminary antitumour activity of ramucirumab (an IgG1 VEGFR-2 antagonist) combined with pembrolizumab (an IgG4 PD-1 antagonist) in patients with previously treated advanced gastric or gastro-oesophageal junction adenocarcinoma, non-small-cell lung cancer, or urothelial carcinoma.

METHODS

We did a multicohort, non-randomised, open-label, phase 1a/b trial at 16 academic medical centres, hospitals, and clinics in the USA, France, Germany, Spain, and the UK. We enrolled adult patients aged 18 years or older with histologically confirmed gastric or gastro-oesophageal junction adenocarcinoma (cohorts A and B), non-small-cell lung cancer (cohort C), or urothelial carcinoma (cohort D), whose disease had progressed on one or two lines of previous therapy (for those with gastric or gastro-oesophageal junction adenocarcinoma) or one to three lines of previous therapy (for those with non-small-cell lung cancer and urothelial carcinoma) that included platinum (for all tumour types) or fluoropyrimidine or both (for gastric or gastro-oesophageal junction adenocarcinoma). Eligibility criteria included presence of measurable disease and an Eastern Cooperative Oncology Group performance status of 0-1. Patients with previously untreated gastric or gastro-oesophageal junction adenocarcinoma and non-small-cell lung cancer were also enrolled (in two additional separate cohorts); the results for these cohorts will be reported separately. The first 21-day treatment cycle was a dose-limiting toxicity observation period (phase 1a; safety run-in), followed by a phase 1b cohort expansion stage. Pembrolizumab 200 mg was administered intravenously on day 1, and intravenous ramucirumab was administered at 8 mg/kg on days 1 and 8 for cohort A or at 10 mg/kg on day 1 for cohorts B, C, and D, every 3 weeks, until disease progression or other discontinuation criteria were met. The primary endpoint was the safety and tolerability of ramucirumab in combination with pembrolizumab assessed by the incidence of adverse events in both phase 1a and 1b and as dose-limiting toxicities during phase 1a. The safety and activity analysis set included all patients who received at least one dose of study treatment. This trial is registered with ClinicalTrials.gov, number NCT02443324, and is no longer enrolling patients.

FINDINGS

Between July 30, 2015 and June 24, 2016, we enrolled and treated 92 patients (41 with gastric or gastro-oesophageal junction adenocarcinoma, 27 with non-small-cell lung cancer, and 24 with urothelial carcinoma). Median follow-up was 32·8 months (IQR 28·1-33·6). During the first cycle of treatment (phase 1a safety run-in; n=11), one patient with gastro-oesophageal junction adenocarcinoma who received the 8 mg/kg dose of ramucirumab had grade 3 abdominal pain, colitis, hepatitis, interstitial lung disease, and jaundice, and grade 4 cholestasis, and died on treatment on day 40; the death was deemed related to progressive disease. No additional dose-limiting toxicities occurred and the decision was made to maintain the full planned doses of ramucirumab and pembrolizumab in phase 1b (n=81). Treatment-related adverse events occurred in 75 (82%) of 92 patients, the most common of which was fatigue (in 33 patients [36%]), predominantly of grade 1 or 2 severity. 22 patients (24%) had one or more treatment-related adverse events of grade 3 or worse, most commonly hypertension (six patients; 7%) and colitis (five patients; 5%). Serious adverse events occurred in 53 (58%) of 92 patients, and were deemed related to treatment in 22 (24%) patients. The most common treatment-related serious adverse events were abdominal pain in patients with gastric or gastro-oesophageal junction adenocarcinoma (in three [7%] of 41 patients); asthenia and myocardial infarction in patients with non-small-cell lung cancer (two [7%] of 27 patients), and colitis in patients with urothelial carcinoma (two [8%] of 24 patients). Six (7%) of 92 patients discontinued treatment because of treatment-related adverse events, and one death (from pulmonary sepsis in a patient with gastric or gastro-oesophageal junction adenocarcinoma) was deemed related to treatment. The number of patients achieving an objective response was three (7%; 95% CI 1·5-19·9) of 41 in the gastric or gastro-oesophageal junction adenocarcinoma cohort, eight (30%; 13·8-50·2) of 27 in the non-small-cell lung cancer cohort, and three (13%, 2·7-32·4) in the urothelial carcinoma cohort.

INTERPRETATION

Ramucirumab in combination with pembrolizumab showed a manageable safety profile with favourable antitumour activity in patients with previously treated advanced gastric or gastro-oesophageal junction adenocarcinoma, non-small-cell lung cancer, and urothelial carcinoma. Our results contribute to the growing evidence that supports dual inhibition of the VEGF-VEGFR2 and PD-1-PD-L1 pathways. This combination could be further explored with or without chemotherapy, especially for patients with tumours for which single-agent checkpoint inhibitors have shown no additional benefit over chemotherapy.

FUNDING

Eli Lilly and Company, and Merck and Co.

Targeting the Tumor Microenvironment in Renal Cell Cancer Biology and Therapy

Renal cell cancer (RCC) is a highly vascularized and immunogenic tumor type. The inhibition of vessel formation by anti-angiogenic therapies, as well as the stimulation of the immune system by immunotherapy has revolutionized the therapeutic landscape of RCC in recent years. Nevertheless, both therapies are associated with therapy resistance due to a highly dynamic, adaptive and heterogeneous tumor microenvironment (TME). The aim of this short review article is to provide an overview of the components of the RCC TME as well as to discuss their contribution to disease progression. In addition, we report on preclinical and clinical findings and how the different TME components can be modulated to impede treatment progression as well as to overcome therapy resistance to anti-angiogenic or immunomodulating therapy concepts. Furthermore, we discuss the predictive and prognostic role of the TME in RCC therapy. We also report on the concept of combinational targeting of anti-angiogenic therapies and immune checkpoint inhibitor therapy, also including the latest results of clinical studies discussed at recent oncological meetings. Finally, promising new therapeutic targets within the TME are mentioned.

Phase I/II Pilot Study of Wilms' Tumor 1 Peptide-Pulsed Dendritic Cell Vaccination Combined With Conventional Chemotherapy in Patients With Head and Neck Cancer

The prognosis of metastatic or relapsed head and neck squamous cell carcinoma (HNSCC) remains poor despite the introduction of immune checkpoint blockade agents. We aimed to investigate the safety and the feasibility of a vaccination with Wilms' tumor 1 peptide-loaded dendritic cells (DCs) and OK-432 adjuvant combined with conventional chemotherapy. Eleven eligible patients with metastatic or relapsed HNSCC were enrolled. No severe adverse events related to a vaccination were observed. Five patients had durable stable disease and six other patients had disease progression after DC vaccination. Median progression-free survival and overall survival was 6.4 months and 12.1 months, respectively. DC vaccination augmented Wilms' tumor 1-specific immunity which might be related to clinical outcome. These results indicate that DC-based immunotherapy combined with a conventional chemotherapy is safe and feasible for patients in advanced stage of HNSCC.

Autologous tumor cell vaccination combined with systemic CpG-B and IFN-α promotes immune activation and induces clinical responses in patients with metastatic renal cell carcinoma: a phase II trial

Background

In this study the toxicity and efficacy of an irradiated autologous tumor cell vaccine (ATV) co-injected with a class-B CpG oligodeoxynucleotide (CpG-B) and GM-CSF, followed by systemic CpG-B and IFN-α administration, were examined in patients with metastatic renal cell carcinoma (mRCC).

Methods

A single-arm Phase II trial was conducted, in which patients with mRCC were intradermally injected with a minimum of three whole-cell vaccines containing 0.7–1.3 × 107 irradiated autologous tumor cells (ATC), admixed with 1 mg CpG-B and 100 µg GM-CSF, followed by bi-weekly s.c. injections with 8 mg CpG-B and s.c. injections with 6 MU IFN-α three times per week.

Results

Fifteen patients were treated according to the protocol. Treatment was well tolerated. Objective clinical responses occurred in three patients, including one long-term complete response. Disease stabilization occurred in another three patients. Positive delayed type hypersensitivity (DTH) responses to ATC were absent before treatment but present in 13 out of 15 patients during treatment. Immune monitoring revealed activation of plasmacytoid dendritic cells, non-classical monocytes and up-regulation of both PD-1 and CTLA4 on effector T cells upon treatment. Moreover, a pre-existing ex vivo IFN-γ response to ATC was associated with clinical response.

Conclusions

ATV combined with systemic CpG-B and IFN-α is tolerable, safe, immunogenic and able to elicit anti-tumor responses in patients with mRCC. Immune activation and treatment-induced up-regulation of PD-1 and CTLA4 on circulating T cells further suggest an added benefit of combining this approach with immune checkpoint blockade [added]

Efficacy, Safety, and Potential Biomarkers of Sunitinib and Transarterial Chemoembolization (TACE) Combination in Advanced Hepatocellular Carcinoma (HCC): Phase II Trial

OBJECTIVES

To evaluate the safety/efficacy and explore biomarkers for a rationally designed combination of sunitinib and transarterial chemoembolization (TACE) in a prospective phase 2 study of advanced hepatocellular carcinoma (HCC).

METHODS

Inoperable HCC patients with Child-Pugh A disease received 37.5 mg sunitinib from days 1 to 7 followed by TACE on day 8. Sunitinib was resumed from days 15 to 36 followed by 2 weeks off. Patients received subsequent sunitinib cycles of 4 weeks on and 2 weeks off. Dynamic contrast-enhanced magnetic resonance imaging and circulating soluble biomarkers were assessed at baseline, day 8, day 10, and day 36.

RESULTS

Sixteen patients with liver only (n=10) and extrahepatic disease (n=6) were enrolled. After a median follow-up of 12.8 months, 2 partial responses, 11 stable disease, and 3 clinical deteriorations were seen for a clinical benefit rate of 81%. Median progression-free survival (PFS) was 8 months (95% CI, 4.3-9.3) and overall survival was 14.9 months (95% CI, 6.3-27.1). Eleven of 16 patients (69%) had grade 3/4 toxicities attributable to sunitinib, the most frequent being thrombocytopenia, amylase/lipase elevations, lymphopenia, and fatigue. Mean K (volume transfer constant) and viable tumor percent in consented patients decreased by 27% and 14.8%, respectively, with combination therapy. Soluble vascular endothelial growth factor receptor-2 (sVEGFR2) levels, cytokines (interleukin-8, interleukin-21), and monocytes decreased with combination therapy. Estimated sunitinib IC50 values of 15 and 10 ng/mL modulated K and AUC90. sVEGFR2 levels decreased with K and AUC90.

CONCLUSIONS

Encouraging progression-free survival and overall survival were seen with acceptable toxicity in our study of sunitinib and TACE combination in advanced HCC. Potential imaging and serum biomarkers showed increased benefit with combination therapy.

Turning the Tide Against Regulatory T Cells

Regulatory T (Treg) cells play crucial roles in health and disease through their immunosuppressive properties against various immune cells. In this review we will focus on the inhibitory role of Treg cells in anti-tumor immunity. We outline how Treg cells restrict T cell function based on our understanding of T cell biology, and how we can shift the equilibrium against regulatory T cells. To date, numerous strategies have been proposed to limit the suppressive effects of Treg cells, including Treg cell neutralization, destabilizing Treg cells and rendering T cells resistant to Treg cells. Here, we focus on key mechanisms which render T cells resistant to the suppressive effects of Treg cells. Lastly, we also examine current limitations and caveats of overcoming the inhibitory activity of Treg cells, and briefly discuss the potential to target Treg cell resistance in the context of anti-tumor immunity.

Cancer DNA vaccines: current preclinical and clinical developments and future perspectives

The recent developments in immuno-oncology have opened an unprecedented avenue for the emergence of vaccine strategies. Therapeutic DNA cancer vaccines are now considered a very promising strategy to activate the immune system against cancer. In the past, several clinical trials using plasmid DNA vaccines demonstrated a good safety profile and the activation of a broad and specific immune response. However, these vaccines often demonstrated only modest therapeutic effects in clinical trials due to the immunosuppressive mechanisms developed by the tumor. To enhance the vaccine-induced immune response and the treatment efficacy, DNA vaccines could be improved by using two different strategies. The first is to increase their immunogenicity by selecting and optimizing the best antigen(s) to be inserted into the plasmid DNA. The second strategy is to combine DNA vaccines with other complementary therapies that could improve their activity by attenuating immunosuppression in the tumor microenvironment or by increasing the activity/number of immune cells. A growing number of preclinical and clinical studies are adopting these two strategies to better exploit the potential of DNA vaccination. In this review, we analyze the last 5-year preclinical studies and 10-year clinical trials using plasmid DNA vaccines for cancer therapy. We also investigate the strategies that are being developed to overcome the limitations in cancer DNA vaccination, revisiting the rationale for different combinations of therapy and the different possibilities in antigen choice. Finally, we highlight the most promising developments and critical points that need to be addressed to move towards the approval of therapeutic cancer DNA vaccines as part of the standard of cancer care in the future.

Persistent restoration to the immunosupportive tumor microenvironment in glioblastoma by bevacizumab

Although vascular endothelial growth factor (VEGF) promotes the immunosuppressive microenvironment, the efficacy of bevacizumab (Bev) on tumor immunity has not been fully investigated. The present study used 47 glioblastoma tissues obtained at 3 different settings: tumors of initial resection (naïve Bev group), tumors resected following Bev therapy (effective Bev group), and recurrent tumors after Bev therapy (refractory Bev group). The paired samples of the initial and post-Bev recurrent tumors from 9 patients were included. The expression of programmed cell death-1 (PD-1)/PD ligand-1 (PD-L1), CD3, CD8, Foxp3, and CD163 was analyzed by immunohistochemistry. The PD-L1+ tumor cells significantly decreased in the effective or refractory Bev group compared with the naïve Bev group (P < .01 for each). The PD-1+ cells significantly decreased in the effective or refractory Bev group compared with the naïve Bev group (P < .01 for each). The amount of CD3+ and CD8+ T cell infiltration increased in the refractory Bev group compared with the naïve Bev group (CD3, P < .01; CD8, P = .06). Both Foxp3+ regulatory T cells and CD163+ tumor-associated macrophages significantly decreased in the effective or refractory Bev group compared with the naïve Bev group (Foxp3, P < .01 for each; CD163, P < .01 for each). These findings were largely confirmed by comparing paired initial and post-Bev recurrent tumors. Bevacizumab restores the immunosupportive tumor microenvironment in glioblastomas, and this effect persists during long-term Bev therapy.

Phase 1 study of everolimus and low-dose oral cyclophosphamide in patients with metastatic renal cell carcinoma

mTOR inhibitors are frequently used in the treatment of metastatic renal cell cancer (mRCC). mTOR regulates cell growth, proliferation, angiogenesis, and survival, and additionally plays an important role in immune regulation. Since mTOR inhibitors were shown to benefit immunosuppressive regulatory T-cell (Treg) expansion, this might suppress antitumor immune responses. Metronomic cyclophosphamide (CTX) was shown to selectively deplete Tregs. This study was, therefore, designed to determine the optimal dosage and schedule of CTX when combined with everolimus to prevent this potentially detrimental Treg expansion. In this national multi-center phase I study, patients with mRCC progressive on first line anti-angiogenic therapy received 10 mg everolimus once daily and were enrolled into cohorts with different CTX dosages and schedules. Besides immune monitoring, adverse events and survival data were monitored. 40 patients, 39 evaluable, were treated with different doses and schedules of CTX. Combined with 10 mg everolimus once daily, the optimal Treg depleting dose and schedule of CTX was 50 mg CTX once daily. 23 (59%) patients experienced one or more treatment-related ≥ grade 3 toxicity, mostly fatigue, laboratory abnormalities and pneumonitis. The majority of the patients achieved stable disease, two patients a partial response. Median PFS of all cohorts was 3.5 months. In conclusion, the optimal Treg depleting dose and schedule of CTX, when combined with everolimus, is 50 mg once daily. This combination leads to acceptable adverse events in comparison with everolimus alone. Currently, the here selected combination is being evaluated in a phase II clinical trial. TRIAL REGISTRATION: NCT01462214.

The Evolving Landscape of Immunotherapy-Based Combinations for Frontline Treatment of Advanced Renal Cell Carcinoma

Insights into the biology of advanced renal cell carcinoma (aRCC) and the development of agents targeting the vascular endothelial growth factor (VEGF) pathway have positively impacted the outcomes for patients with aRCC. With the recent approval of the dual immune checkpoint inhibitors (ICIs), nivolumab and ipilimumab, by the U.S. Food and Drug Administration (USFDA), and the European Medicines Agency (EMA), the era of VEGF monotherapy for untreated aRCC appears to be coming to an end for patients with access to the combination therapy. The frontline treatment options for renal cell carcinoma are evolving rapidly and will lead to the approval of other combination immunotherapies-especially those with VEGF inhibitors. Here we review the clinical data for dual immune checkpoint inhibition with nivolumab plus ipilimumab as well as the emerging data for ICI plus VEGF inhibitor combinations and discuss the challenges these will pose for the clinical practitioner.

Vascular Targeting to Increase the Efficiency of Immune Checkpoint Blockade in Cancer

Boosting natural immunity against malignant cells has had a major breakthrough in clinical cancer therapy. This is mainly due to the successful development of immune checkpoint blocking antibodies, which release a break on cytolytic anti-tumor-directed T-lymphocytes. However, immune checkpoint blockade is only effective for a proportion of cancer patients, and a major challenge in the field is to understand and overcome treatment resistance. Immune checkpoint blockade relies on successful trafficking of tumor-targeted T-lymphocytes from the secondary lymphoid organs, through the blood stream and into the tumor tissue. Resistance to therapy is often associated with a low density of T-lymphocytes residing within the tumor tissue prior to treatment. The recruitment of leukocytes to the tumor tissue relies on up-regulation of adhesion molecules and chemokines by the tumor vasculature, which is denoted as endothelial activation. Tumor vessels are often poorly activated due to constitutive pro-angiogenic signaling in the tumor microenvironment, and therefore constitute barriers to efficient leukocyte recruitment. An emerging possibility to enhance the efficiency of cancer immunotherapy is to combine pro-inflammatory drugs with anti-angiogenic therapy, which can enable tumor-targeted T-lymphocytes to access the tumor tissue by relieving endothelial anergy and increasing adhesion molecule expression. This would pave the way for efficient immune checkpoint blockade. Here, we review the current understanding of the biological basis of endothelial anergy within the tumor microenvironment, and discuss the challenges and opportunities of combining vascular targeting with immunotherapeutic drugs as suggested by data from key pre-clinical and clinical studies.

Ramucirumab Plus Pembrolizumab in Patients with Previously Treated Advanced or Metastatic Biliary Tract Cancer: Nonrandomized, Open-Label, Phase I Trial (JVDF)

LESSONS LEARNED

Ramucirumab plus pembrolizumab revealed no unexpected safety findings in patients with advanced or metastatic biliary tract cancer, which is consistent with reports of other tumor cohorts within this phase Ia/b trial.Ramucirumab plus pembrolizumab did not demonstrate an improvement in overall survival when compared with historical controls in biomarker unselected, heavily pretreated patients with advanced or metastatic biliary tract cancer.Patients with programmed death-ligand 1 (PD-L1)-positive tumors had improved overall survival compared with patients with PD-L1-negative disease.

BACKGROUND

Few treatment options exist for patients with advanced biliary tract cancer (BTC) following progression on gemcitabine-cisplatin. Preclinical evidence suggests that simultaneous blockade of vascular endothelial growth factor receptor 2 (VEGFR-2) and programmed death 1 (PD-1) or programmed death-ligand 1 (PD-L1) enhances antitumor effects. We assessed the safety and efficacy of ramucirumab, an IgG1 VEGFR-2 antagonist, with pembrolizumab, an IgG4 PD-1 antagonist, in biomarker-unselected patients with previously treated advanced or metastatic BTC.

METHODS

Patients had previously treated advanced or metastatic adenocarcinoma of the gallbladder, intrahepatic and extrahepatic bile ducts, or ampulla of Vater. Ramucirumab 8 mg/kg was administered intravenously on days 1 and 8 with intravenous pembrolizumab 200 mg on day 1 every 3 weeks. The primary endpoint was safety and tolerability of the combination. Secondary endpoints included objective response rate (ORR), progression-free survival (PFS), and overall survival (OS).

RESULTS

Twenty-six patients were treated at 12 centers in five countries. Hypertension was the most common grade 3 treatment-related adverse event (TRAE), occurring in five patients. One patient experienced a grade 4 TRAE (neutropenia), and no treatment-related deaths occurred. Objective response rate was 4%. Median progression-free survival and overall survival were 1.6 months and 6.4 months, respectively.

CONCLUSION

Ramucirumab-pembrolizumab showed limited clinical activity with infrequent grade 3-4 TRAEs in patients with biomarker-unselected progressive BTC.

Spontaneous regression of adrenal metastasis from renal cell carcinoma after sunitinib withdrawal: case report and literature review

Background

The spontaneous regression of metastatic renal cell carcinoma is a rare phenomenon, with an estimated incidence of < 1%. We report a case of post-nephrectomy renal cell carcinoma adrenal metastasis, followed by the spontaneous regression of the metastasis after withdrawal of sunitinib.

Case presentation

The patient was a 55-year-old male with clear cell type renal cell carcinoma who previously underwent a left laparoscopic radical nephrectomy. After 51 months of follow up, a recurrence in the left renal fossa was observed and subsequently excised. Four months after excision, an abdominal Computerized tomography (CT) identified an adrenal metastasis of 1.6 cm. The patient was treated with sunitinib. However, the treatment was discontinued because of gastrointestinal side effects and fatigue. Eleven months after the discontinuation of sunitinib treatment, a progression in the adrenal metastasis growth (5.7 cm) was observed, whereas 16 months after the discontinuation, a regression of the adrenal metastasis growth (3.4 cm) was observed. During subsequent follow-ups, a gradual reduction in the size of the adrenal metastasis (1.8 cm) was observed. After 44 months from the discontinuation of sunitinib treatment, the patient was still alive and followed up in the outpatient department.

Conclusions

Sunitinib is a multi-targeted inhibitor of vascular endothelial growth factor (VEGF) receptors. This compound reduces tumor angiogenesis and has been approved worldwide for the treatment of advanced renal cell carcinoma. To our knowledge, this is the fourth case of the spontaneous regression of metastatic renal cell carcinoma after the discontinuation of sunitinib treatment.

Combination Therapy with EpCAM-CAR-NK-92 Cells and Regorafenib against Human Colorectal Cancer Models

Adoptive chimeric antigen receptor-modified T or NK cells (CAR-T or CAR-NK) offer new options for cancer treatment. CAR-T therapy has achieved encouraging breakthroughs in the treatment of hematological malignancies. However, their therapeutic efficacy against solid tumors is limited. New regimens, including combinations with chemical drugs, need to be studied to enhance the therapeutic efficacy of CAR-T or NK cells for solid tumors. An epithelial cell adhesion molecule- (EpCAM-) specific second-generation CAR was constructed and transduced into NK-92 cells by lentiviral vectors. Immune effects, including cytokine release and cytotoxicity of the CAR-NK-92 cells against EpCAM-positive colon cancer cells, were evaluated in vitro. Synergistic effects of regorafenib and CAR-NK-92 cells were analyzed in a mouse model with human colorectal cancer xenografts. The CAR-NK-92 cells can specifically recognize EpCAM-positive colorectal cancer cells and release cytokines, including IFN-γ, perforin, and granzyme B, and show specific cytotoxicity in vitro. The growth suppression efficacy of combination therapy with regorafenib and CAR-NK-92 cells on established EpCAM-positive tumor xenografts was more significant than that of monotherapy with CAR-NK-92 cells or regorafenib. Our results provided a novel strategy to treat colorectal cancer and enhance the therapeutic efficacy of CAR-modified immune effector cells for solid tumors.

ODM-203, a Selective Inhibitor of FGFR and VEGFR, Shows Strong Antitumor Activity, and Induces Antitumor Immunity

Alterations in the gene encoding for the FGFR and upregulation of the VEGFR are found often in cancer, which correlate with disease progression and unfavorable survival. In addition, FGFR and VEGFR signaling synergistically promote tumor angiogenesis, and activation of FGFR signaling has been described as functional compensatory angiogenic signal following development of resistance to VEGFR inhibition. Several selective small-molecule FGFR kinase inhibitors are currently in clinical development. ODM-203 is a novel, selective, and equipotent inhibitor of the FGFR and VEGFR families. In this report we show that ODM-203 inhibits FGFR and VEGFR family kinases selectively and with equal potency in the low nanomolar range (IC₅₀ 6-35 nmol/L) in biochemical assays. In cellular assays, ODM-203 inhibits VEGFR-induced tube formation (IC₅₀ 33 nmol/L) with similar potency as it inhibits proliferation in FGFR-dependent cell lines (IC₅₀ 50-150 nmol/L). In vivo, ODM-203 shows strong antitumor activity in both FGFR-dependent xenograft models and in an angiogenic xenograft model at similar well-tolerated doses. In addition, ODM-203 inhibits metastatic tumor growth in a highly angiogenesis-dependent kidney capsule syngenic model. Interestingly, potent antitumor activity in the subcutaneous syngenic model correlated well with immune modulation in the tumor microenvironment as indicated by marked decrease in the expression of immune check points PD-1 and PD-L1 on CD8 T cells and NK cells, and increased activation of CD8 T cells. In summary, ODM-203 shows equipotent activity for both FGFR and VEGFR kinase families and antitumor activity in both FGFR and angigogenesis models.

Cardiovascular oncology: exploring the effects of targeted cancer therapies on atherosclerosis

PURPOSE OF REVIEW

Targeted cancer therapies have revolutionized the treatment of cancer in the past decade, but cardiovascular toxicity is a rising problem in cancer patients. Here we discuss the effects of targeted cancer therapies on atherosclerosis. Increasing the awareness of these adverse effects will promote the development of evidence-based preventive strategies in the emerging field of cardiovascular oncology.

RECENT FINDINGS

Vascular endothelial growth factor inhibitors, immunomodulatory imide drugs, tyrosine kinase inhibitors and immune checkpoint inhibitors are successfully used as treatment for many types of solid and hematologic malignancies. However, clinical and experimental studies have demonstrated that these drugs can drive atherosclerosis, thereby causing adverse cardiovascular events such as myocardial infarction, stroke and peripheral arterial occlusive diseases.

SUMMARY

In this review, we discuss how on-target and off-target effects of novel cancer drugs may affect atherosclerosis and we postulate how these cardiovascular adverse events can be prevented in the future.

Bridging angiogenesis and immune evasion in the hypoxic tumor microenvironment

Hypoxia (low O₂) is a ubiquitous microenvironmental factor promoting cancer progression, metastasis, and mortality, owing to the ability of cancer cells to co-opt physiological angiogenic responses. Notwithstanding, the pathophysiological induction of angiogenesis results in an abnormal tumor vasculature, further aggravating hypoxia in a feedforward loop that limits the efficacy of molecular targeted therapies. Recent studies suggest that, besides their canonical roles, angiogenic factors promote a panoply of immunosuppressive effects in the tumor microenvironment. Therefore, intratumoral hypoxia emerges as a hitherto unrecognized mechanism evolutionarily repurposing angiogenic molecules as (patho)physiological immunomodulators. On the other hand, antiangiogenic therapies could be aimed at impeding both tumor growth and immunotolerance toward cancer cells, a beneficial effect that can be countered if hypoxia signaling pathways are left unchecked, leading to therapeutic failure. This review summarizes evidence supporting the hypothesis that hypoxia acts as a common pathophysiological mechanism of resistance to immunotherapeutic and antiangiogenic agents while proposing potential strategies to curtail resistance and mortality in patients bearing solid malignancies.

Current and emerging therapies for first-line treatment of metastatic clear cell renal cell carcinoma

There has been significant progress in the treatment of patients with advanced clear cell renal cell carcinoma (ccRCC), with improved knowledge of disease biology and the introduction of targeted agents and immunotherapies. In this review, we discuss current and emerging first-line treatment options, including recent approvals of the tyrosine kinase inhibitor (TKI) cabozantinib and the immunotherapy combination of nivolumab (anti-programmed cell death 1 [PD-1])/ipilimumab (anti-cytotoxic T-lymphocyte-associated antigen 4 [CTLA-4]), and initial outcomes with the combination of atezolizumab (anti-PD-ligand 1 [PD-L1])/bevacizumab (anti-vascular endothelial growth factor [VEGF]). Key clinical data are reviewed, as these novel first-line treatments offer significant improvement, particularly for patients classified as intermediate/poor risk for whom previously available therapies have demonstrated limited efficacy. Treatment recommendations based on clinical evidence and expert opinion are discussed. We also review ongoing studies investigating combinations of checkpoint inhibitors with TKIs, including cabozantinib and axitinib, and with other novel immunomodulatory agents, and the potential role of single-agent immunotherapy for select patients. With a growing treatment armamentarium, identification and validation of biomarkers will be crucial for optimizing first-line selection and treatment sequences.

Vaccination of Urological Cancer Patients With WT1 Peptide-Pulsed Dendritic Cells in Combination With Molecular Targeted Therapy or Conventional Chemotherapy Induces Immunological and Clinical Responses

The prognosis of metastatic or relapsed renal cell carcinoma (RCC) or bladder cancer (BC) remains poor despite the introduction of immune checkpoint blockade agents. We aimed to investigate the safety and the feasibility of a vaccination with WT1 peptide-loaded dendritic cells (DCs) and OK-432 adjuvant combined with molecular targeted therapy or conventional chemotherapy. Five eligible patients with metastatic or relapsed RCC and five eligible patients with BC were enrolled. No severe adverse events related to a vaccination were observed. Seven patients with RCC or non-muscle invasive BC had durable stable disease and three other patients had disease progression after DC vaccination. DC vaccination augmented WT1 specific immunity and the reduction of regulatory T cells which might be related to clinical outcome. These results indicate that DC-based immunotherapy combined with a molecular targeted therapy or a conventional chemotherapy is safe and feasible for patients in advanced stage of RCC or BC.

Targeting VEGF/VEGFR to Modulate Antitumor Immunity

In addition to the crucial role in promoting the growth of tumor vessels, vascular endothelial growth factor (VEGF) is also immunosuppressive. VEGF can inhibit the function of T cells, increase the recruitment of regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs), and hinder the differentiation and activation of dendritic cells (DCs). Recent studies have investigated the role of antiangiogenic agents in antitumor immunity, especially in recent 3 years. Therefore, it is necessary to update the role of targeting VEGF/VEGFR in antitumor immunity. In this review, we focus on the latest clinical and preclinical findings on the modulatory role of antiangiogenic agents targeting VEGF/VEGFR in immune cells, including effector T cells, Tregs, MDSCs, DCs, tumor-associated macrophages, and mast cells. Our review will be potentially helpful for the development of combinations of angiogenesis inhibitors with immunological modulators.

Renal cell carcinoma in one year: Going inside the news of 2017 - A report of the main advances in RCC cancer research

Very interesting issues regarding RCC treatment have been raised during 2017. We analysed the main news that may potentially modified clinical practice. Conflicting data came from trials testing targeted therapies in the adjuvant setting, supporting the necessity of further investigations. One of the key goals of RCC research is focused on the first-line therapy, with particular interest focus on immunotherapy combinations. Redefine the standard of care with the aim of improving patients' survival represents an imperative need. Enhancing immunotherapy antitumor activity by combining immune checkpoint inhibitors with anti-angiogenetic therapies is a noteworthy research field, with promising results. In addiction, we analysed in the metastatic setting data about the role of cytoreductive nephrectomy and the possibility of delay the start of first-line therapy after an active surveillance period. Based on recent developments, the paper outlines future prospective of RCC research.

First-line vascular endothelial growth factor targeted therapy in renal cell carcinoma: priming the tumor microenvironment for immunotherapy

Despite improved outcomes with systemic vascular endothelial growth factor (VEGF)-targeted agents in patients with advanced renal cell carcinoma (RCC), the majority of patients will eventually develop treatment resistance and disease progression. With the emergence of checkpoint inhibitors as potential treatment approaches, studies suggest that ideally combining or sequencing them with VEGF receptor (VEGFR)-tyrosine kinase inhibitors (TKIs) may provide more effective treatments that reduce or delay disease progression. Indeed, preliminary evidence suggests that VEGFR-TKIs can reverse immunosuppressive effects in the tumor microenvironment, potentially enhancing the effects of subsequent immunotherapy with checkpoint inhibitors. However, questions remain regarding the most effective treatment sequences or combinations with VEGFR-TKIs and checkpoint inhibitors. This review discusses the potential role of first-line VEGFR-TKIs in priming the tumor microenvironment for immunotherapy.

Shining light on advanced NSCLC in 2017: combining immune checkpoint inhibitors

The treatment landscape has changed since the immune checkpoint inhibitors were approved in the treatment of non-small cell lung cancer (NSCLC). Although the promising clinical benefit from programmed death-1/programmed death ligand-1 (PD-1/PD-L1) inhibitors was observed in the second or subsequent line treatment of patients who progressed on chemotherapy, it has a long way for single PD-1/PD-L1 inhibitor to move forward to the frontline without a predictive biomarker. Tumor response is far from satisfactory without selection and primary or acquired resistance to PD-1/PD-L1 inhibitors hampered their utility. Therefore, it is crucial to determine a strategy that can optimize the application of immune checkpoint inhibitors and increase the numbers of the responders. Multiple combination approaches based on PD-1/PD-L1 inhibitors are designed and aimed to boost anti-tumor response and benefit a broader population. In this review, we will integrate the updated clinical data to highlight the four most promising combination strategies in advance NSCLC: combination of checkpoint inhibition with chemotherapy, anti-angiogenesis, immunotherapy and radiotherapy. We further discuss the issues needed to be addressed and perspectives in the context of "combination era".

Clinical Benefit from Tyrosine Kinase Inhibitors in Metastatic Merkel Cell Carcinoma: A Case Series of 5 Patients

Case series

Patients: Male, 58 • Male, 65 • Male, 75 • Male, 61 • Male, 69

Final Diagnosis: Merkel cell carcinoma

Symptoms: Metastatic disease

Medication: Pazopanib • Cabozantinib

Clinical Procedure: Systemic therapy

Specialty: Oncology

Correlates of immune and clinical activity of novel cancer vaccines

Cancer vaccines are solely meant to amplify the pool of type 1 cytokine oriented CD4+ and CD8+ T cells that recognize tumor antigen and ultimately foster control and destruction of a growing tumor. They are not designed to deal with all aspects of immune ignorance, exclusion, suppression and escape that are generally in place in patients with cancer and may prevent the T cells to enter the tumor or to exert their effector function. This simple fact prompted for a reappraisal of the many recent trials in which therapeutic cancer vaccines have been examined as monotherapy. In this review, I focus on trials examining therapeutic cancer vaccines at different stages of existing disease. The analysis of vaccine-induced immune responses and clinical activity of therapeutic cancer vaccines revealed four levels of evidence for vaccine efficacy. The lowest levels, reflect the many trials in which the strength of the tumor-reactive T cell response of vaccinated patients is associated with better clinical outcome or change in tumor marker. The highest levels indicate occasional regressions of tumors and metastases after vaccination or reflect a stronger clinical impact of vaccine in a randomized trial. A whole series of trials in which vaccine-induced tumor immunity correlates with the clinical impact of cancer vaccines in premalignant diseases, settings of low tumor burden or tumor regressions in patients with cancer, form an attest to the fact that cancer vaccines work. While the current number of true clinical responders in each cancer trial is too low for firm conclusions on immune correlates of clinical reactivity in cancer, extrapolation of the results from vaccinated patients with pre-cancers suggest a requirement of broad type 1 T cell reactivity.

TK Inhibitor Pazopanib Primes DCs by Downregulation of the β-Catenin Pathway

Tyrosine kinase inhibitors (TKIs) target angiogenesis by affecting, for example, the VEGF receptors in tumors and have improved outcomes for patients with metastatic renal cell carcinoma (mRCC). Immune checkpoint inhibitors (ICIs) have also been proposed for treatment of mRCC with encouraging results. A better understanding of the activity of immune cells in mRCC, the immunomodulatory effects of TKIs, and the characteristics defining patients most likely to benefit from various therapies will help optimize immunotherapeutic approaches. In this study, we investigated the influence of the TKI pazopanib on dendritic cell (DC) performance and immune priming. Pazopanib improved DC differentiation and performance by promoting upregulation of the maturation markers HLA-DR, CD40, and CCR7; decreasing IL10 production and endocytosis; and increasing T-cell proliferation. PD-L1 expression was also downregulated. Our results demonstrate that pazopanib inhibits the Erk/β-catenin pathway, suggesting this pathway might be involved in increased DC activation. Similar results were confirmed in DCs differentiated from mRCC patients during pazopanib treatment. In treated patients pazopanib appeared to enhance a circulating CD4⁺ T-cell population that expresses CD137 (4-1BB). These results suggest that a potentially exploitable immunomodulatory effect induced by pazopanib could improve responses of patients with mRCC in customized protocols combining TKIs with ICI immunotherapy. Cancer Immunol Res; 6(6); 711-22. ©2018 AACR.

Accumulation of High Levels of Monocytic Myeloid-Derived Suppressor Cells Enhances Graft Survival in Almost-Tolerant Kidney Transplant Recipients

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature cells that suppress immune responses during organ transplantation and participate in mediating long-term graft survival and immune tolerance in animal transplant models. However, their role in regulating transplant tolerance in human subjects is not well understood. In the present study, we investigated the role of MDSCs in mediating long-term graft survival in almost-tolerant kidney transplant recipients (ATKTRs) and the mechanism(s) responsible for increasing MDSC numbers in these recipients.

METHODS

Peripheral blood mononuclear cells (PBMCs) from whole blood samples were collected from 30 ATKTRs (graft survival, > 10 years after kidney transplant [KTx]) treated with low doses of immunosuppressive drugs and with stable kidney function, 10 short-term graft survival kidney transplant recipients (STKTRs; graft survival, ∼1-3 years post-KTx) with stable kidney function, and 10 healthy donors (HDs). MDSC and regulatory T cell (Tregs) levels were analyzed using multicolor flow cytometry in PBMCs.

RESULTS

ATKTRs had significantly higher levels of monocytic MDSCs (P < .001) and CD4⁺CD25⁺FoxP3⁺ Tregs than STKTRs and HDs. Furthermore, the M-MDSC levels correlated positively with the survival rates, estimated glomerular filtration rates (eGFRs) of grafts, and the levels of CD4⁺CD25⁺FoxP3⁺ Tregs in ATKTRs.

CONCLUSIONS

Accumulation of high levels of MDSCs was observed in ATKTRs. Changes in MDSC levels may play important roles in mediating transplant tolerance and regulating Tregs. Therefore, we propose that MDSCs may be potentially used for recognizing tolerant transplant recipients and guiding dosage reduction for immunosuppressive drugs for KTx.

Synergistic anti-tumor effects of dasatinib and dendritic cell vaccine on metastatic breast cancer in a mouse model

Immunotherapy is currently considered as one of the major anti-tumor modalities, but its efficacy is limited. Dasatinib could improve the expansion and recruitment of cluster of differentiation (CD) 8⁺T cells and natural killer (NK) cells to the tumor microenvironment. The present study aimed to evaluate the synergistic anti-tumor effects of dasatinib with dendritic cell (DC) vaccine in metastatic breast cancer. Dasatinib with DC vaccine was administered to mice inoculated with 4T1 breast cancer cells. Thereafter, tumor volume was measured every other day. On day 34, lung metastasis was assessed with a stereomicroscope. Tumor proliferation and angiogenesis were determined by immunohistochemistry. Apoptosis in tumor tissues was assessed by terminal deoxynucleotidyl transferase dUTP nick end labeling. The results showed that although there were no significant differences in tumor volumes between the untreated control, DC vaccine and dasatinib groups, the tumor volume was significantly decreased in the combined treatment group compared to the other three groups. Mice in the combined treatment group showed the longest survival time, while mice treated with either single treatment had a slightly increased survival time compared to the untreated control mice. Additionally, the number of metastatic lung nodules was significantly decreased in combined treatment group compared with the dasatinib alone, DC vaccine alone and untreated control groups. Furthermore, the combined treatment group showed significantly reduced intratumoral microvessel density compared to the other three groups. In addition, the ratios of CD8⁺ T and NK cells were significantly increased in the combined treatment group compared with the other three groups. These results suggest that dasatinib combined with the DC vaccine is a possible modality for the treatment of metastatic breast cancer.

Immune consequences of anti-angiogenic therapyin renal cell carcinoma

Current therapies of renal cell carcinoma (RCC), a highly vascularised tumour, mostly rely on anti-angiogenic treatment options. These include tyrosine kinase inhibitors (TKIs) and anti-VEGF monoclonal antibodies. Although these strategies aim at restraining vascularisation to control tumour growth, the effects of such therapies are much wider, as affecting the vessel structure deeply modifies the microenvironment of the tumour mass. The aim of this review is to provide an overview of current knowledge on the global effects of anti-angiogenic treatment, mostly TKIs, on the shaping of the immune component of the RCC microenvironment. The data supporting the modification of immunity by anti-angiogenic therapies are collected to reveal the potential of angiogenesis modulation as a strategy for the adjuvant anti-cancer approach in immunotherapy.

Present status and future perspective of peptide-based vaccine therapy for urological cancer

Use of peptide‐based vaccines as therapeutics aims to elicit immune responses through antigenic epitopes derived from tumor antigens. Peptide‐based vaccines are easily synthesized and lack significant side‐effects when given in vivo. Peptide‐based vaccine therapy against several cancers including urological cancers has made progress for several decades, but there is no worldwide approved peptide vaccine. Peptide vaccines were also shown to induce a high frequency of immune response in patients accompanied by clinical efficacy. These data are discussed in light of the recent progression of immunotherapy caused by the addition of immune checkpoint inhibitors thus providing a general picture of the potential therapeutic efficacy of peptide‐based vaccines and their combination with other biological agents. In this review, we discuss the mechanism of the antitumor effect of peptide‐based vaccine therapy, development of our peptide vaccine, recent clinical trials using peptide vaccines for urological cancers, and perspectives of peptide‐based vaccine therapy.

HLA class I expression predicts prognosis and therapeutic benefits from tyrosine kinase inhibitors in metastatic renal-cell carcinoma patients

PURPOSE

Classical HLA class I antigen is highly involved in antigen presentation and adaptive immune response against tumor. In this study, we explored its predictive value for treatment response and survival in metastatic renal-cell carcinoma (mRCC) patients.

EXPERIMENTAL DESIGN

A TKI cohort of 111 mRCC patients treated with sunitinib or sorafenib and a non-TKI cohort of 160 mRCC patients treated with interleukin-2 or interferon-α-based immunotherapy at a single institution were retrospectively enrolled. HLA class I expression and cytotoxic T lymphocyte (CTL) density was assessed by immunohistochemistry on tissue microarrays. Association between HLA class I and CTL was also assessed in the TCGA KIRC cohort.

RESULTS

In the TKI cohort, down-regulated HLA class I was associated with lower objective response rate of TKI therapy (P = 0.004), shorter overall survival (OS) (P = 0.001), and shorter progression free survival (PFS) (P < 0.001). Multivariate Cox regression model defined HLA expression as an independent prognostic factor for both OS [hazard ratio 1.687 (95% CI 1.045-2.724), P = 0.032] and PFS [hazard ratio 2.139 (95% CI 1.376-3.326), P = 0.001]. In the non-TKI cohort, HLA class I was not significantly associated with survival. HLA class I expression was associated with CTL infiltration and function, and its prognostic value was more predominant in CTL high-density tumors (P < 0.001) rather than CTL low-density tumors (P = 0.294).

CONCLUSIONS

Classical HLA class I expression can serve as a potential predictive biomarker for TKI therapy in mRCC patients. Its predictive value was restricted in CTL high-density tumors. However, further external validations and functional investigations are still required.

Targeted Therapies: Immunologic Effects and Potential Applications Outside of Cancer

Two pharmacologic approaches that are currently at the forefront of treating advanced cancer are those that center on disrupting critical growth/survival signaling pathways within tumor cells (commonly referred to as "targeted therapies") and those that center on enhancing the capacity of a patient's immune system to mount an antitumor response (immunotherapy). Maximizing responses to both of these approaches requires an understanding of the oncogenic events present in a given patient's tumor and the nature of the tumor-immune microenvironment. Although these 2 modalities were developed and initially used independently, combination regimens are now being tested in clinical trials, underscoring the need to understand how targeted therapies influence immunologic events. Translational studies and preclinical models have demonstrated that targeted therapies can influence immune cell trafficking, the production of and response to chemokines and cytokines, antigen presentation, and other processes relevant to antitumor immunity and immune homeostasis. Moreover, because these and other effects of targeted therapies occur in nonmalignant cells, targeted therapies are being evaluated for use in applications outside of oncology.

Inhibition of JAK2/STAT3 reduces tumor-induced angiogenesis and myeloid-derived suppressor cells in head and neck cancer

Angiogenesis is an essential event in tumor growth and metastasis, and immune system also contributes to the tumor evasion. Emerging evidences have suggested the bidirectional link between angiogenesis and immunosuppression. Myeloid-derived suppressor cell (MDSC) is a kind of immunosuppressive cells and plays an important role in this process. However, the actual regulatory mechanisms of angiogenesis and MDSCs in head and neck squamous cell carcinoma (HNSCC) were unclear. In this study, through analyzing the immunohistochemistry staining of human HNSCC tissue microarray, we found that the microvascular density (MVD) was significantly increased in HNSCC patients. We also characterized angiogenic factors p-STAT3, VEGFA, CK2, and MDSCs marker CD11b in HNSCC tissue array, and found the close expression correlation among these markers. To determine the role of JAK2/STAT3 pathway in tumor microenvironment of HNSCC, we utilized AG490 (an inhibitor of JAK2/STAT3) for further research. Results showed that inhibition of JAK2/STAT3 suppressed angiogenesis by decreasing VEGFA and HIF1-α both in vitro and vivo. Moreover, in HNSCC transgenic mouse model, inhibiting JAK2/STAT3 not only suppressed angiogenesis but also reduced MDSCs in the tumor microenvironment through suppressing VEGFA and CK2. Our findings demonstrated the close relationship between angiogenesis and MDSCs in HNSCC, and inhibition of JAK2/STAT3 could reduce tumor-induced angiogenesis and decrease MDSCs.

Resistance to anticancer immunity in cancer patients: potential strategies to reverse resistance

In the 1990s, the application of immunotherapy approaches to target cancer cells resulted in significant clinical responses in patients with advanced malignancies who were refractory to conventional therapies. While early immunotherapeutics were focused on T cell-mediated cytotoxic activity, subsequent efforts were centered on targeted antibody-mediated anticancer therapy. The initial success with antibody therapy encouraged further studies and, consequently, there are now more than 25 FDA-approved antibodies directed against a range of targets. Although both T cell and antibody therapies continue to result in significant clinical responses with minimal toxicity, a significant subset of patients does not respond to immunotherapy and another subset develops resistance following an initial response. This review is focused on describing examples showing that cancer resistance to immunotherapies indeed occurs. In addition, it reviews the mechanisms being used to overcome the resistance to immunotherapies by targeting the tumor cell directly and/or the tumor microenvironment.

Synergistic Effects of Cabozantinib and EGFR-Specific CAR-NK-92 Cells in Renal Cell Carcinoma

The chimeric antigen receptor-modified immune effector cell (CAR-T and CAR-NK) therapies are newly developed adoptive treatments of cancers. However, their therapeutic efficacy against solid tumors is limited. Combining CAR-T or CAR-NK cells with chemotherapeutic drugs to treat solid tumor may be a promising strategy. We developed an epidermal growth factor- (EGFR-) specific third-generation CAR. NK-92 cells were modified with the CAR by lentivirus infection. The specific killing ability of the CAR-modified NK-92 cells (CAR-NK-92) against renal cell carcinoma (RCC) cell lines was confirmed in vitro. The synergistic effects of cabozantinib and EGFR-specific CAR-NK-92 cells were investigated in vitro and in vivo. Our results showed that the CAR-NK-92 cells lyse RCC cells in an EGFR-specific manner. Treatment with cabozantinib could increase EGFR and decrease PD-L1 membrane surface expression in RCC cells and enhance the killing ability of CAR-NK-92 cells against the RCC cells in vitro. Furthermore, the CAR-NK-92 cells show synergistic therapeutic efficacy with cabozantinib against human RCC xenograft models. Our results provided the basis for combination with chemotherapy as a novel strategy for enhancing the therapeutic efficacy of CAR-modified immune effector cells for solid tumors.

Amplification of Oncolytic Vaccinia Virus Widespread Tumor Cell Killing by Sunitinib through Multiple Mechanisms

Oncolytic viruses pose many questions in their use in cancer therapy. In this study, we assessed the potential of mpJX-594 (mouse-prototype JX-594), a replication-competent vaccinia virus administered by intravenous injection, to target the tumor vasculature, produce immune activation and tumor cell killing more widespread than the infection, and suppress invasion and metastasis. These actions were examined in RIP-Tag2 transgenic mice with pancreatic neuroendocrine tumors that developed spontaneously and progressed as in humans. mpJX-594 initially infected tumor vascular endothelial cells, leading to vascular pruning and prolonged leakage in tumors but not in normal organs; parallel effects were observed in U87 gliomas. Viral infection spread to tumor cells, where tumor cell killing was much more widespread than the infection. Widespread tumor cell killing at 5 days was prevented by depletion of CD8⁺ T lymphocytes and did not require GM-CSF, as mpJX-594 variants that expressed human, mouse, or no GM-CSF produced equivalent amounts of killing. The antivascular, antitumor, and antimetastatic effects of mpJX-594 were amplified by concurrent or sequential administration of sunitinib, a multitargeted receptor tyrosine kinase inhibitor. These effects were not mimicked by selective inhibition of VEGFR2 despite equivalent vascular pruning, but were accompanied by suppression of regulatory T cells and greater influx of activated CD8⁺ T cells. Together, our results showed that mpJX-594 targets tumor blood vessels, spreads secondarily to tumor cells, and produces widespread CD8⁺ T-cell-dependent tumor cell killing in primary tumors and metastases, and that these effects can be amplified by coadministration of sunitinib.Significance: These findings reveal multiple unrecognized features of the antitumor properties of oncolytic vaccinia viruses, all of which can be amplified by the multitargeted kinase inhibitor sunitinib. Cancer Res; 78(4); 922-37. ©2017 AACR.