VEGF as a mediator of tumor-associated immunodeficiency

Combinations using checkpoint blockade to overcome resistance

The advent of immunotherapy for cancer represented a paradigm shift in the treatment approach of neoplasia. Immune-checkpoint inhibitors (ICIs) were demonstrated to significantly improve outcomes, including overall survival across several cancer types, with yearly-durable responses. Nevertheless, many patients derive minor or no benefit with immune checkpoint (IC)-blockade, including patients with cancer types traditionally considered immunogenic. Combination strategies of ICIs with chemotherapy, radiotherapy, targeted therapies or other immunotherapy compounds have been conceived in order to boost the immune-responses and potentially overcome resistance to ICIs. This review focuses on mechanisms underlying resistance to IC-blockade and provides an overview of potential advantages and limitations of combination strategies currently under investigation.

Atezolizumab in combination with bevacizumab and chemotherapy versus bevacizumab and chemotherapy in recurrent ovarian cancer - a randomized phase III trial (AGO-OVAR 2.29/ENGOT-ov34)

BACKGROUND

Improvement in clinical outcomes of patients with platinum-resistant disease is an unmet medical need and trials in this population are urgently needed. Checkpoint-inhibitors have already shown activity in multiple other tumor entities and ovarian cancer, especially in the combination with anti-angiogenic treatment.

PRIMARY OBJECTIVE

To test if the activity of non-platinum-based chemotherapy and bevacizumab could be improved by the addition of atezolizumab.

STUDY HYPOTHESIS

The addition of atezolizumab to standard non-platinum combination of chemotherapy and bevacizumab improves median overall survival from 15 to 20 months.

TRIAL DESIGN

Patients are randomized to chemotherapy (paclitaxel weekly or pegylated liposomal doxorubicin) + bevacizumab + placebo vs chemotherapy + bevacizumab + atezolizumab. Stratification factors are: number of prior lines, planned type of chemotherapy, prior use of bevacizumab, and tumor programmed death-ligand 1 (PD-L1) status.

MAJOR INCLUSION/EXCLUSION CRITERIA

Recurrent epithelial ovarian, fallopian tube, or primary peritoneal cancer with up to three prior therapies and a treatment-free interval after platinum of less than 6 months. Patients with three prior lines of chemotherapy are eligible irrespective of the platinum free-interval. A de novo tumor tissue sample biopsy for determination of PD-L1 status prior to randomization for stratification is mandatory. Major exclusion criteria consider bevacizumab-specific and immunotherapy-specific criteria.

PRIMARY ENDPOINT

Overall survival and progression-free survival are co-primary endpoints.

SAMPLE SIZE

It is planned to randomize 664 patients.

TRIAL REGISTRATION

NCT03353831.

Immuno-priming durvalumab with bevacizumab in HER2-negative advanced breast cancer: a pilot clinical trial

BACKGROUND

Preclinical research suggests that the efficacy of immune checkpoint inhibitors in breast cancer can be enhanced by combining them with antiangiogenics, particularly in a sequential fashion. We sought to explore the efficacy and biomarkers of combining the anti-PD-L1 durvalumab plus the antiangiogenic bevacizumab after bevacizumab monotherapy for advanced HER2-negative breast cancer.

METHODS

Patients had advanced HER2-negative disease that progressed while receiving single-agent bevacizumab maintenance as a part of a previous chemotherapy plus bevacizumab regimen. Treatment consisted of bi-weekly durvalumab plus bevacizumab (10 mg/kg each i.v.). Peripheral-blood mononuclear cells (PBMCs) were obtained before the first durvalumab dose and every 4 weeks and immunophenotyped by flow-cytometry. A fresh pre-durvalumab tumor biopsy was obtained; gene-expression studies and immunohistochemical staining to assess vascular normalization and characterize the immune infiltrate were conducted. Patients were classified as "non-progressors" if they had clinical benefit (SD/PR/CR) at 4 months. The co-primary endpoints were the changes in the percentage T cell subpopulations in PBMCs in progressors versus non-progressors, and PFS/OS time.

RESULTS

Twenty-six patients were accrued. Median PFS and OS were 3.5 and 11 months; a trend for a longer OS was detected for the hormone-positive subset (19.8 versus 7.4 months in triple-negatives; P = 0.11). Clinical benefit rate at 2 and 4 months was 60% and 44%, respectively, without significant differences between hormone-positive and triple-negative (P = 0.73). Non-progressors' tumors displayed vascular normalization features as a result of previous bevacizumab, compared with generally abnormal patterns observed in progressors. Non-progressors also showed increased T-effector and T-memory signatures and decreased TREG signatures in gene expression studies in baseline-post-bevacizumab-tumors compared with progressors. Notably, analysis of PBMC populations before durvalumab treatment was concordant with the findings in tumor samples and showed a decreased percentage of circulating TREGs in non-progressors.

CONCLUSIONS

This study reporting on sequential bevacizumab+durvalumab in breast cancer showed encouraging activity in a heavily pre-treated cohort. The correlative studies agree with the preclinical rationale supporting an immunopriming effect exerted by antiangiogenic treatment, probably by reducing TREGs cells both systemically and in tumor tissue. The magnitude of this benefit should be addressed in a randomized setting.

TRIAL REGISTRATION

(www.clinicaltrials.gov): NCT02802098 . Registered on June 16, 2020.

The Effect and Safety of Anti-PD-1 Single/Combination Therapy in Refractory Thymic Carcinoma: A Case-Series Study

Immunotherapy provided with checkpoint inhibitors such as the programmed cell death-1 (PD-1) receptor or its ligand-1 (PD-L1) protein has been shown to be effective for treating several types of cancer, and was recently approved for use in treating malignant melanoma, advanced non-small cell lung cancer (NSCLC), urothelial carcinoma, head and neck squamous cell carcinoma, liver cancer, and additional forms of cancer. However, there is little evidence concerning its effectiveness in treating thymic squamous cell carcinoma (TSCC). Here, we report two cases of refractory TSCC that were treated with PD-1 single/combination therapy in a clinical setting. The patients exhibited variable responses to therapy without any serious adverse events. In summary, our findings show that immunotherapy provided with an immuno-checkpoint inhibitor in combination with chemotherapy/anti-angiogenesis therapy can improve the treatment response of patients with refractory TSCC. Anti-PD-1 single/combination therapy may be used as a strategy for treating advanced refractory TC.

Parenteral Bevacizumab for the Treatment of Severe Respiratory Papillomatosis in an Adult Population

OBJECTIVES/HYPOTHESIS

Recurrent respiratory papillomatosis (RRP) is a rare, potentially life-threatening, disease that impacts the voice, breathing, and quality of life of patients. Frequent surgical interventions may be needed to control symptoms. We examined the safety and efficacy of utilizing parenteral bevacizumab in the management of severe RRP in adults.

STUDY DESIGN

This is a retrospective review of clinical management approaches in a group of patients with severe RRP defined as having a high disease burden, frequent need for debridement, and/or tracheobronchial disease. Patients were initially treated with 15 mg/kg of bevacizumab at 3-week intervals. Bevacizumab dosing and frequency was then individually titrated down.

RESULTS

Fourteen adults received a median of 8.5 (range 2-17) bevacizumab infusions over approximately 24 months. All had a history of laryngeal RRP with 6/14 having additional tracheobronchial lesions. Patients required a median of 4 (range 2-11) procedures in the year prior to treatment. Only 3/10 (30%) patients who continued therapy required any additional procedures. Bevacizumab administration was generally well tolerated, with four patients discontinuing therapy. Medical reasons included severe epistaxis and hypertension and thrombocytopenia in an individual with systemic lupus erythematosus. Common side effects included hypertension (grade 2), headache (grades 1-2), elevated creatinine (grades 1-2), and epistaxis (grade 3).

CONCLUSIONS

Intravenous bevacizumab for the primary treatment of severe RRP in adults appears clinically effective and safe. Expected and typically mild side effects related to bevacizumab were observed. Continued investigation of bevacizumab through a prospective clinical trial is warranted.

LEVEL OF EVIDENCE

4. Laryngoscope, 131:E921-E928, 2021.

TiNivo: safety and efficacy of tivozanib-nivolumab combination therapy in patients with metastatic renal cell carcinoma

BACKGROUND

Treatment with tivozanib, a highly selective and potent vascular endothelial growth factor receptor tyrosine kinase inhibitor, has demonstrated single-agent efficacy in advanced renal cell carcinoma (RCC) along with minimal off-target toxicities and a favorable adverse event (AE) profile. We report final results from TiNivo, a phase Ib/II study of tivozanib combined with nivolumab.

PATIENTS AND METHODS

In phase Ib, patients with metastatic RCC received tivozanib 1.0 mg once daily (QD) for 21 days followed by 7 days off treatment (n = 3) or tivozanib 1.5 mg QD (n = 3) plus nivolumab 240 mg every 2 weeks. The maximum tolerated dose was determined to be tivozanib 1.5 mg, and 22 additional patients were enrolled at the maximum tolerated dose for phase II. Primary end points included safety and tolerability, with secondary end points of objective response rate, disease control rate, and progression-free survival.

RESULTS

In total, 25 patients were treated with tivozanib 1.5 mg QD [12 (48%) treatment-naïve; 13 (52%) previously treated]. Treatment-related grade 3/4 AEs were reported in 20 patients (80%); 4 patients (17%) experienced AEs that led to dose reduction, and 8 (32%) discontinued due to AEs. The objective response rate was 56% (including one complete response) and disease control rate was 96%, with a median time to best response of 7.9 weeks. Twenty patients (80%) had tumor shrinkage. With a median follow-up of 19.0 months (range, 12.6-22.8), median progression-free survival was 18.9 months (95% confidence interval 16.4-not reached) in all patients and was similar in treatment-naïve and previously treated patients.

CONCLUSIONS

Tivozanib plus nivolumab combination therapy showed a generally tolerable AE profile and promising antitumor efficacy. These results support further development of tivozanib combined with nivolumab as a treatment option in patients with treatment-naïve or previously treated metastatic RCC.

CLINICAL TRIAL NUMBER

NCT03136627.

Antitumor and immunomodulatory effects of a novel multitarget inhibitor, CS2164, in mouse hepatocellular carcinoma models

As a novel orally active multitarget small molecule inhibitor, CS2164 has shown broad antitumor activities against several human tumor xenograft models in immune-compromised mice. However, the ability of CS2164 to modulate antitumor immunity in an immune-competent mouse tumor model remains undefined, although antiangiogenic treatment has been reported to affect immune cell infiltration and remodel the tumor immune microenvironment. In the present study, the subcutaneous and ascites hepatocellular carcinoma (HCC) models in syngeneic Balb/c mice established by inoculation of an H22 hepatoma cell line were utilized to investigate the antitumor and immunomodulatory effects of CS2164. Although the antitumor effects of CS2164 were validated in both subcutaneous and ascites HCC models in syngeneic mice, CS2164 treatment consistently modulated immune cell populations, both in the periphery and in tumor microenvironments, with upregulation of CD4⁺ and CD8⁺ T cells in the spleen, but downregulation of immunosuppressive populations including regulatory T cells, myeloid-derived suppressor cells, and tumor-associated macrophages in the spleen and tumor tissues. Furthermore, CS2164 increased the relative gene expression and protein production of several proinflammatory cytokines in tumor-related ascites. These results indicate that CS2164 exerts an antitumor effect associated with its immunomodulatory activities in mouse HCC models, and may also provide evidence for the immunotherapy potentiation of CS2164 in future cancer treatment.

Mechanism-based treatment of cancer with immune checkpoint inhibitor therapies

Immune checkpoints are cell surface molecules that initiate regulatory pathways which have powerful control of CD8+ cytolytic T cell activity. Antagonistic and agonistic antibodies engaging these molecules have demonstrated profound impact on immune activation and have entered clinical use for the treatment of a variety of diseases. Over the past decade, antagonistic antibodies known as immune checkpoint inhibitors have become a new pillar of cancer treatment and have reshaped the therapeutic landscape in oncology. These agents differ in their mechanism of action and toxicity profiles compared to more traditional systemic cancer treatments such as chemo- and targeted therapies. This article reviews the pharmacology of this new class of agents.

Resisting Resistance to Immune Checkpoint Therapy: A Systematic Review

The treatment landscape in oncology has witnessed a major revolution with the introduction of checkpoint inhibitors: anti-PD1, anti-PDL1 and anti-CTLA-4. These agents enhance the immune response towards cancer cells instead of targeting the tumor itself, contrary to standard chemotherapy. Although long-lasting durable responses have been observed with immune checkpoints inhibitors, the response rate remains relatively low in many cases. Some patients respond in the beginning but then eventually develop acquired resistance to treatment and progress. Other patients having primary resistance never respond. Multiple studies have been conducted to further elucidate these variations in response in different tumor types and different individuals. This paper provides an overview of the mechanisms of resistance to immune checkpoint inhibitors and highlights the possible therapeutic approaches under investigation aiming to overcome such resistance in order to improve the clinical outcomes of cancer patients.

Interaction between Immunotherapy and Antiangiogenic Therapy for Cancer

Although immunotherapy has led to durable responses in diverse cancers, unfortunately, there has been limited efficacy and clinical response rates due to primary or acquired resistance to immunotherapy. To maximize the potential of immunotherapy, combination therapy with antiangiogenic drugs seems to be promising. Some phase III trials showed superiority for survival with the combination of immunotherapy and antiangiogenic therapy. In this study, we describe a synergistic mechanism of immunotherapy and antiangiogenic therapy and summarize current clinical trials of these combinations.

Tumor Endothelial Cells (TECs) as Potential Immune Directors of the Tumor Microenvironment - New Findings and Future Perspectives

The tumor microenvironment (TME) plays a central role in cancer development and progression. It represents a complex network of cancer cell (sub-)clones and a variety of stromal cell types. Recently, new technology platforms shed light on the cellular composition of the TME at very high resolution and identified a complex landscape of multi-lineage immune cells (e.g., T and B lymphocytes, myeloid cells, and dendritic cells), cancer associated fibroblasts (CAF) and tumor endothelial cells (TECs). A growing body of evidence suggests that metabolically, genetically and on their transcriptomic profile TECs exhibit unique phenotypic and functional characteristics when compared to normal endothelial cells (NECs). Furthermore, the functional role of TECs is multifaceted as they are not only relevant for promoting tumor angiogenesis but have also evolved as key mediators of immune regulation in the TME. Regulatory mechanisms are complex and profoundly impact peripheral immune cell trafficking into the tumor compartment by acting as major gatekeepers of cellular transmigration. Moreover, TECs are associated with T cell priming, activation and proliferation by acting as antigen-presenting cells themselves. TECs are also essential for the formation of tertiary lymphoid structures (TLS) within the tumor, which have recently been associated with treatment response to checkpoint antibody therapy. Further essential characteristics of TECs compared to NECs are their high proliferative potential as well as greatly altered gene expression profile (e.g., upregulation of pro-angiogenic, extracellular matrix remodeling, and stemness genes), which results in enhanced secretion of immunomodulatory cytokines and altered cell-surface receptors [e.g., major histocompatibility complex (MHC) and immune checkpoints]. The TEC phenotype may be rooted in an aggressive tumor micro-milieu based on cellular stress via hypoxia and reactive oxygen species (ROS). Vice versa TECs might modulate TME immunogenicity thereby fostering cancer-associated immune suppression. This review aims to elucidate the currently emergent pathophysiological aspects of TECs with a particular focus on their potential role as regulators of immune cell function in the TME. It is a main future challenge to deeply characterize the phenotypic and functional profile of TECs to illuminate their complex role within the TME. The ultimate goal is the identification of TEC-specific drug targets to improve cancer (immuno-)therapy.

Apatinib enhanced anti-PD-1 therapy for colon cancer in mice via promoting PD-L1 expression

Increasing studies confirm that anti-angiogenesis can increase the effectiveness of immunotherapy. In this study, we found that an angiogenesis inhibitor apatinib enhanced anti-PD-1 therapy for colon cancer in mice via promoting PD-L1 expression. Apatinib treatment upregulated PD-L1 expression in various colon cancer cells both at the mRNA and protein levels. Further, apatinib-treated cancer cells hampered activation and IFN-γ secretion of T cells in the co-culture system, which was reversed by the anti-PD-1 antibody. Based on this, the combination of apatinib with anti-PD-1 on colon cancer growth in mice was examined. The combination treatment showed more significant inhibition on the growth of transplanted tumors in mice than single-drug treatment. Overall, our study here showed the enhancement of anti-PD-1 antitumor efficacy in a syngeneic mouse model (CT-26 cells in Balb/c) by the angiogenesis inhibitor apatinib via upregulating PD-L1 expression as well as angiogenesis inhibition, which may provide a rationale for the combination of apatinib and anti-PD-1 antibody for colorectal cancer treatment in the clinic.

Immune phenotyping of diverse syngeneic murine brain tumors identifies immunologically distinct types

Immunotherapy has emerged as a promising approach to treat cancer, however, its efficacy in highly malignant brain-tumors, glioblastomas (GBM), is limited. Here, we generate distinct imageable syngeneic mouse GBM-tumor models and utilize RNA-sequencing, CyTOF and correlative immunohistochemistry to assess immune-profiles in these models. We identify immunologically-inert and -active syngeneic-tumor types and show that inert tumors have an immune-suppressive phenotype with numerous exhausted CD8 T cells and resident macrophages; fewer eosinophils and SiglecF+ macrophages. To mimic the clinical-settings of first line of GBM-treatment, we show that tumor-resection invigorates an anti-tumor response via increasing T cells, activated microglia and SiglecF+ macrophages and decreasing resident macrophages. A comparative CyTOF analysis of resected-tumor samples from GBM-patients and mouse GBM-tumors show stark similarities in one of the mouse GBM-tumors tested. These findings guide informed choices for use of GBM models for immunotherapeutic interventions and offer a potential to facilitate immune-therapies in GBM patients.

Syngeneic mouse models for glioblastoma (GBM) cannot fully recapitulate clinical findings and response to therapy in patients. Here the authors perform a comprehensive immune profiling of different syngeneic GBM tumour models and compare it with the immune landscape of GBM patients to identify similarities and potential confounding differences.

Anlotinib as a molecular targeted therapy for tumors

Angiogenesis has an essential role in tumor growth and metastasis, and blocking this pathway has been a successfully utilized strategy in the clinical treatment of cancer. Anlotinib (AL3818) is a novel oral receptor tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor 2 and 3, fibroblast growth factor 1-4, platelet-derived growth factor receptor α and β, c-Kit and Ret. Anlotinib exerts inhibitory effects on tumor growth and angiogenesis and received its first approval as a third-line treatment for refractory advanced non-small-cell lung cancer in May 2018 and its second approval as a second-line treatment for advanced soft-tissue sarcoma in June 2019 in the People's Republic of China. Anlotinib has encouraging efficacy and a manageable and tolerable safety profile in a broad range of malignancies, including medullary thyroid cancer, renal cell cancer, gastric cancer and esophageal squamous cell carcinoma. In the present review, the preclinical and clinical trials of anlotinib were summarized with a focus on safety evaluation and adverse event management.

Myeloid Cells as Clinical Biomarkers for Immune Checkpoint Blockade

Immune checkpoint inhibitors are becoming standard treatments in several cancer types, profoundly changing the prognosis of a fraction of patients. Currently, many efforts are being made to predict responders and to understand how to overcome resistance in non-responders. Given the crucial role of myeloid cells as modulators of T effector cell function in tumors, it is essential to understand their impact on the clinical outcome of immune checkpoint blockade and on the mechanisms of immune evasion. In this review we focus on the existing clinical evidence of the relation between the presence of myeloid cell subsets and the response to anti-PD(L)1 and anti-CTLA-4 treatment. We highlight how circulating and tumor-infiltrating myeloid populations can be used as predictive biomarkers for immune checkpoint inhibitors in different human cancers, both at baseline and on treatment. Moreover, we propose to follow the dynamics of myeloid cells during immunotherapy as pharmacodynamic biomarkers. Finally, we provide an overview of the current strategies tested in the clinic that use myeloid cell targeting together with immune checkpoint blockade with the aim of uncovering the most promising approaches for effective combinations.

[Immunotherapy of metastatic non-small cell lung cancer from first line to resistance and its management]

Immunotherapy alone or in combination with chemotherapy is now an integral part of the treatment of metastatic NSCLC. This treatment is transforming the management of these cancers, with 20-30% of patients achieving long survival. However, disease progression under treatment is still the rule for the majority of patients, raising problems both in understanding its mechanisms and in subsequent appropriate management. This study examines current therapeutic options and proposes solutions to circumvent resistance to immunotherapy. The mechanisms of resistance to these treatments is also analysed.

Phase II Study of Immunotherapy With Tecemotide and Bevacizumab After Chemoradiation in Patients With Unresectable Stage III Non-Squamous Non-Small-Cell Lung Cancer (NS-NSCLC): A Trial of the ECOG-ACRIN Cancer Research Group (E6508)

INTRODUCTION

Although chemoradiotherapy (CRT) is the standard of care for patients with unresectable stage III non-small-cell lung cancer (LA-NSCLC), most patients relapse. Tecemotide is a MUC1 antigen-specific cancer immunotherapy vaccine. Bevacizumab improves survival in advanced nonsquamous (NS)-NSCLC and has a role in immune modulation. This phase II trial tested the combination of tecemotide and bevacizumab following CRT in patients with LA-NSCLC.

PATIENTS AND METHODS

Subjects with stage III NS-NSCLC suitable for CRT received carboplatin/paclitaxel weekly + 66 Gy followed by 2 cycles of consolidation carboplatin/paclitaxel ≤ 4 weeks of completion of CRT (Step 1). Patients with partial response/stable disease after consolidation therapy were registered onto step 2, which was 6 weekly tecemotide injections followed by every 6 weekly injections and bevacizumab every 3 weeks for up to 34 doses. The primary endpoint was to determine the safety of this regimen.

RESULTS

Seventy patients were enrolled; 68 patients (median age, 63 years; 56% male; 57% stage IIIA) initiated therapy, but only 39 patients completed CRT and consolidation therapy per protocol, primarily owing to disease progression or toxicity. Thirty-three patients (median age, 61 years; 58% male; 61% stage IIIA) were registered to step 2 (tecemotide + bevacizumab). The median number of step 2 cycles received was 11 (range, 2-25). Step 2 worst toxicity included grade 3, N = 9; grade 4, N = 1; and grade 5, N = 1. Grade 5 toxicity in step 2 was esophageal perforation attributed to bevacizumab. Among the treated and eligible patients (n = 32) who were treated on step 2, the median overall survival was 42.7 months (95% confidence interval, 21.7-63.3 months), and the median progression-free survival was 14.9 months (95% confidence interval, 11.0-20.9 months) from step 1 registration.

CONCLUSIONS

This cooperative group trial met its endpoint, demonstrating tolerability of bevacizumab + tecemotide after CRT and consolidation. In this selected group of patients, the median progression-free survival and overall survival are encouraging. Given that consolidation immunotherapy is now a standard of care following CRT in patients with LA-NSCLC, these results support a role for continued investigation of antiangiogenic and immunotherapy combinations in LA-NSCLC.

Hepatocellular carcinoma, novel therapies on the horizon

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and is associated with high mortality rate. Incidence remains high due to the persistent prevalence of viral hepatitis, alcoholic cirrhosis, and non-alcoholic fatty liver disease (NFLD). Despite screening efforts, the majority of patients present with advanced disease, add to the high risk of recurrence after curative surgery. Conventional chemotherapy did not alter the nature history of advanced and metastatic HCC. The discovery of multiple tyrosine kinase inhibitors (TKIs) led to the approval of sorafenib as first efficacious therapy. A new era in the treatment paradigm of HCC is evolving. Since the advent of sorafenib as an active treatment option for patients presenting with advanced or metastatic disease, several agents have been examined. This was linked with many failures, and success stories to celebrate. Herein, we describe the historical progress and current advances of systemic therapies post-sorafenib. Lenvatinib, regorafenib, cabozantinib, ramucirumab, pembrolizumab, and nivolumab, are all presently added and available therapeutic options in the advanced setting. The evaluation of novel treatment combinations including anti-angiogenic, TKIs plus checkpoint inhibitors, add to dual checkpoint inhibitors is evolving rapidly starting with the advent of the combination of atezolizumab plus bevacizumab. Combining local and systemic therapies is being actively investigated, as an option for locally advanced disease conventionally treated with locoregional approaches. The horizon remains promising and continues to evolve for HCC a disease long considered with unmet needs.

MDA-9/Syntenin (SDCBP): Novel gene and therapeutic target for cancer metastasis

The primary cause of cancer-related death from solid tumors is metastasis. While unraveling the mechanisms of this complicated process continues, our ability to effectively target and treat it to decrease patient morbidity and mortality remains disappointing. Early detection of metastatic lesions and approaches to treat metastases (both pharmacological and genetic) are of prime importance to obstruct this process clinically. Metastasis is complex involving both genetic and epigenetic changes in the constantly evolving tumor cell. Moreover, many discrete steps have been identified in metastatic spread, including invasion, intravasation, angiogenesis, attachment at a distant site (secondary seeding), extravasation and micrometastasis and tumor dormancy development. Here, we provide an overview of the metastatic process and highlight a unique pro-metastatic gene, melanoma differentiation associated gene-9/Syntenin (MDA-9/Syntenin) also called syndecan binding protein (SDCBP), which is a major contributor to the majority of independent metastatic events. MDA-9 expression is elevated in a wide range of carcinomas and other cancers, including melanoma, glioblastoma multiforme and neuroblastoma, suggesting that it may provide an appropriate target to intervene in metastasis. Pre-clinical studies confirm that inhibiting MDA-9 either genetically or pharmacologically profoundly suppresses metastasis. An additional benefit to blocking MDA-9 in metastatic cells is sensitization of these cells to a second therapeutic agent, which converts anti-invasion effects to tumor cytocidal effects. Continued mechanistic and therapeutic insights hold promise to advance development of truly effective therapies for metastasis in the future.

Novel immunotherapy combinations for genitourinary cancers

Introduction: Several immune checkpoint inhibitors are FDA-approved for metastatic/advanced RCC and urothelial carcinoma (UC) based on improvements in survival. The dendritic cell vaccine, sipuleucel-T, is also approved for patients with mCRPC, based on a 4-month survival benefit.Areas covered: Preclinical evidence suggests that there is promise in combining immune checkpoint inhibitors with several different classes of anti-cancer agents, including tumor-directed vaccines, cytokines, chemotherapy, and multi-targeted tyrosine kinase inhibitors. Here we review immunotherapy combinations currently approved for RCC, UC, and prostate cancer with a focus on emerging therapies. We conducted a search of peer-reviewed publications and recent meeting abstracts and provide an overview of ongoing combination immunotherapy trials for genitourinary malignancies and discussion of preliminary findings where available.Expert opinion: Recently, many potential immunotherapy combinations have emerged. In addition to determining clinical activity, important challenges include investigating additive adverse effects and determining the best sequence of therapy.

A randomized phase III trial of platinum chemotherapy plus paclitaxel with bevacizumab and atezolizumab versus platinum chemotherapy plus paclitaxel and bevacizumab in metastatic (stage IVB), persistent, or recurrent carcinoma of the cervix: the BEATcc study (ENGOT-Cx10/GEICO 68-C/JGOG1084/GOG-3030)

BACKGROUND

Patients with metastatic, recurrent, or persistent cervical cancer not amenable to local control and/or distant metastases have a very poor prognosis, only being candidates for palliative-systemic therapy. First line standard treatment in this scenario is based on cisplatin/paclitaxel plus bevacizumab (GOG 240 regimen) with a short median overall survival (16.8 months) and progression-free survival (8.2 months).

PRIMARY OBJECTIVE

To determine whether the addition of atezolizumab to cisplatin-paclitaxel and bevacizumab improves overall survival, compared with cisplatin-paclitaxel plus bevacizumab in patients with metastatic, recurrent, or persistent cervical cancer.

STUDY HYPOTHESIS

The primary hypothesis is whether the addition of atezolizumab to cisplatin-paclitaxel and bevacizumab improves overall survival in metastatic, recurrent, or persistent cervical cancer.

TRIAL DESIGN

The BEATcc study is a phase III, randomized, open-label, multi-center clinical trial. The study will be performed on an intent-to-treat population. The control arm is the administration of chemotherapy (platinum plus paclitaxel) and bevacizumab, while the experimental arm is the administration of atezolizumab in combination with the same chemotherapy regimen (1:1 randomization). The trial will be run under the ENGOT umbrella alongside JGOG and GOG-F. GEICO is the lead group on behalf of ENGOT.

MAJOR INCLUSION/EXCLUSION CRITERIA

Women over 18 years old with histologically or cytologically confirmed diagnosis of squamous cell carcinoma, adenocarcinoma, or adenosquamous metastatic, recurrent, or persistent cervical cancer, not amenable for curative treatment with surgery and/or radiation therapy, will be included. Women are not eligible if they have received prior systemic anti-cancer therapy for metastatic or persistent/recurrent disease or they have disease involving the bladder or rectum at the screening/baseline pelvic magnetic resonance imaging.

PRIMARY ENDPOINT

Overall survival, defined as the observed length of life from entry into the study (day of randomization) to death from any cause or the date of last contact.

SAMPLE SIZE

A total of 404 patients are expected to be recruited into the study, assuming a total 10% drop-out rate. In order to test whether the experimental arm improves overall survival, the study will have 80% power using one-sided α of 0.025. There will be one interim analysis to close the study in case of early efficacy results in the experimental arm.

ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS

The trial was launched in Q3 2018 and the trial is estimated to close in Q3 2022. We expect to be able to report mature data from the BEATcc trial by 2023.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT03556839).

Adjuvant bevacizumab for melanoma patients at high risk of recurrence: survival analysis of the AVAST-M trial

Background

Bevacizumab is a recombinant humanised monoclonal antibody to vascular endothelial growth factor shown to improve survival in advanced solid cancers. We evaluated the role of adjuvant bevacizumab in melanoma patients at high risk of recurrence.

Patients and methods

Patients with resected AJCC stage IIB, IIC and III cutaneous melanoma were randomised to receive either adjuvant bevacizumab (7.5 mg/kg i.v. 3 weekly for 1 year) or standard observation. The primary end point was detection of an 8% difference in 5-year overall survival (OS) rate; secondary end points included disease-free interval (DFI) and distant metastasis-free interval (DMFI). Tumour and blood were analysed for prognostic and predictive markers.

Results

Patients (n=1343) recruited between 2007 and 2012 were predominantly stage III (73%), with median age 56 years (range 18–88 years). With 6.4-year median follow-up, 515 (38%) patients had died [254 (38%) bevacizumab; 261 (39%) observation]; 707 (53%) patients had disease recurrence [336 (50%) bevacizumab, 371 (55%) observation]. OS at 5 years was 64% for both groups [hazard ratio (HR) 0.98; 95% confidence interval (CI) 0.82–1.16, P = 0.78). At 5 years, 51% were disease free on bevacizumab versus 45% on observation (HR 0.85; 95% CI 0.74–0.99, P = 0.03), 58% were distant metastasis free on bevacizumab versus 54% on observation (HR 0.91; 95% CI 0.78–1.07, P = 0.25). Forty four percent of 682 melanomas assessed had a BRAF^V600 mutation. In the observation arm, BRAF mutant patients had a trend towards poorer OS compared with BRAF wild-type patients (P = 0.06). BRAF mutation positivity trended towards better OS with bevacizumab (P = 0.21).

Conclusions

Adjuvant bevacizumab after resection of high-risk melanoma improves DFI, but not OS. BRAF mutation status may predict for poorer OS untreated and potential benefit from bevacizumab.

Clinical Trial Information

ISRCTN 81261306; EudraCT Number: 2006-005505-64

N-Terminal Modification of the Tetrapeptide Arg-Leu-Tyr-Glu, a Vascular Endothelial Growth Factor Receptor-2 (VEGFR-2) Antagonist, Improves Antitumor Activity by Increasing its Stability against Serum Peptidases

The tetrapeptide Arg-Leu-Tyr-Glu (RLYE), a vascular endothelial growth factor (VEGF) receptor-2 antagonist, has been used previously either alone or in combination with chemotherapeutic drugs for treating colorectal cancer in a mouse model. We analyzed the half-life of the peptide and found that because of degradation by aminopeptidases B and N, it had a short half-life of 1.2 hours in the serum. Therefore, to increase the stability and potency of the peptide, we designed the modified peptide, N-terminally acetylated RLYE (Ac-RLYE), which had a strongly stabilized half-life of 8.8 hours in serum compared with the original parent peptide. The IC50 value of Ac-RLYE for VEGF-A-induced endothelial cell migration decreased to approximately 37.1 pM from 89.1 pM for the parent peptide. Using a mouse xenograft tumor model, we demonstrated that Ac-RLYE was more potent than RLYE in inhibiting tumor angiogenesis and growth, improving vascular integrity and normalization through enhanced endothelial cell junctions and pericyte coverage of the tumor vasculature, and impeding the infiltration of macrophages into tumor and their polarization to the M2 phenotype. Furthermore, combined treatment of Ac-RLYE and irinotecan exhibited synergistic effects on M1-like macrophage activation and apoptosis and growth inhibition of tumor cells. These findings provide evidence that the N-terminal acetylation augments the therapeutic effect of RLYE in solid tumors via inhibition of tumor angiogenesis, improvement of tumor vessel integrity and normalization, and enhancement of the livery and efficacy of the coadministered chemotherapeutic drugs. SIGNIFICANCE STATEMENT: The results of this study demonstrate that the N-terminal acetylation of the tetrapeptide RLYE (Ac-RLYE), a novel vascular endothelial growth factor receptor-2 (VEGFR-2) inhibitor, significantly improves its serum stability, antiangiogenic activity, and vascular normalizing potency, resulting in enhanced therapeutic effect on solid tumors. Furthermore, the combined treatment of Ac-RLYE with the chemotherapeutic drug, irinotecan, synergistically enhanced its antitumor efficacy by improving the perfusion and delivery of the drug into the tumors and stimulating the conversion of the tumor-associated macrophages to an immunostimulatory M1-like antitumor phenotype.

New Strategies for Therapeutic Cancer Vaccines

BACKGROUND

Patients with low response rates to cancer vaccines, short duration of anti-tumor response after vaccination, and relatively weak curative effects are problems that have not been resolved effectively during the development and application of cancer vaccines. With the continuous improvement of knowledge and awareness regarding the immune system and cancer cells, many researches have helped to explain the reasons for poor vaccine efficacy. Input from researchers accompanied by some newly emerged strategies could bring hope to improve the therapeutic effects of vaccines.

METHODS

Data were collected from Web of Science, Medline, Pubmed, through searching of these keywords: "cancer vaccine", "cancer stem cell", "targeted agent", "immune checkpoint blockade" and "neoantigen".

RESULTS

It may be more effective in immunotherapy of human cancers, including cancer stem cell vaccines, combination vaccines with targeted agents or immune checkpoint blockade, and neoantigen-based vaccines.

CONCLUSION

Personalized vaccines will become the mainstream solution of cancer treatment program with the continuous improvement of human understanding of the immune system and the progress of related experiments.

Adverse Events of Concurrent Immune Checkpoint Inhibitors and Antiangiogenic Agents: A Systematic Review

Background: Immune checkpoint blockade has revolutionized the treatment of multiple malignancies. Currently, however, the effect is not universal, with objective response rates (ORR) of about 15–25%, and even lower for some cancers. Abnormal vasculature is a hallmark of most solid tumors and plays a role in immune evasion. Growing body of evidence suggests that vascular normalization and immune reprogramming could operate synergistic effect, resulting in an enhanced therapeutic efficacy. However, the benefit of antitumor efficacy must be weighed against the risk of added toxicity. In this systematic review, we summarize severe toxicity observed in such a kind of combination regimen.

Methods: PubMed and Embase were searched for English references published up to May 31, 2019, with MeSH and keywords search terms of immune checkpoint inhibitors (ICIs) and antiangiogenic agents approved for using in solid tumors. Studies performing concomitant use of ICIs and antiangiogenic agents, and also reporting severe treatment-related adverse events (trAEs) (≥grade 3), were included for further analysis.

Results: A total of 32 studies including a total of 2,324 participants were analyzed. Limited available data suggests that both antiangiogenic monoclonal antibodies (mAbs) and tyrosine kinase inhibitors (TKIs) show potential risk of increasing treatment-related toxicity when combined with ICIs. Overall, the total incidence of severe adverse events (AEs) associated with ICIs plus mAbs (44.5%) is lower than that of ICIs plus TKIs (60.1%). However, the trAEs observed in combination therapy are mostly consistent with the known safety profiles of corresponding monotherapy, and they seem to be largely related to antiangiogenic agents, rather than a true immune-related adverse event (irAE) predominantly due to ICIs. The majority of trAEs are intervened by holding ICI treatment and adding corticosteroids, as well as reducing dose or adjusting administration frequency of the antiangiogenic drugs.

Conclusions: Concurrent use of ICIs and antiangiogenic agents shows potential treatment-related toxicity. Further research is required to compare the efficacy and safety of the combination regimen and corresponding monotherapy and identify predictive biomarkers, as well as explore dose, duration, and sequencing schedules of drugs.

The Journey of an EGFR-Mutant Lung Adenocarcinoma through Erlotinib, Osimertinib and ABCP Immunotherapy Regimens: Sensitivity and Resistance

Patients with epidermal growth factor receptor (EGFR) mutation positive non-small cell lung cancer (NSCLC) have several EGFR targeting tyrosine kinase inhibitors (TKIs) available in frontline management. However, the disease will inevitably progress over time due to acquired resistance. Longitudinal tumor profiling for genomics guided therapy is indicated upon disease progression. It is a common scenario yet, when after failure of EGFR-TKIs, potentially actionable genomic alterations are lacking. Management of such patient is challenging with very limited options available. Combination of chemotherapy, anti-vascular/anti-angiogenic and immune-checkpoint inhibitors may become a salvage option for such patients. Here we describe a case of TKI refractory EGFR-mutant NSCLC successfully treated with carboplatin, paclitaxel, atezolizumab and bevacizumab combination with remarkable prompt tumor response.

A thorny pathway of macrophage activating factor (GcMAF): from bench to bedside

Vitamin D3 Binding Protein (DBP) is a multifunctional glycoprotein whose main role is to transport vitamin D3 and its metabolites, but it also is the precursor of the macrophage activating factor (GcMAF). DBP is converted to GcMAF as a result of site-specific selective deglycosylation under the action of β-galactosidase and sialidase, localized on activated B and T cells, respectively. GcMAF exerts its biological activity primarily as the capability of activating macrophages by enhancing their phagocytic function and producing ROS. Activation results in elevated expression of the specific macrophageal surface receptors involved in the recognition of tumor-associated antigens, as well as in the implementation of direct anticancer activity by inducing the apoptosis or necrosis of tumor cells. Increased interest in GcMAF is associated with its potential to be used in the clinic as a new antitumor drug. Besides its anti-tumor activity, GcMAF exerts a potential against a number of viral and neurodegenerative diseases associated with increased activity of N-acetylgalactosaminidase (nagalase) in the blood serum of patients. Nagalase is an enzyme that completely (rather than selectively) deglycosylates DBP so it cannot be converted to GcMAF, leading to immunodeficiency. Circulating DBP is composed of unmodified and O-glycosylated molecules with the glycosylation degree being dependent on the allelic variants of the gene encoding DBP. The role of DBP in the resistance of organism against a number of diseases is supported by the increased risk of a variety of severe illnesses (amyotrophic lateral sclerosis, colorectal cancer etc.) in patients deficient for GcMAF due to homozygosity for defective DBP alleles. In this review, we also will examine in detail the current data i) on the structure and functions of DBP, as the main precursor of GcMAF, ii) on the main mechanisms of GcMAF anticancer effect, iii) on the tumor strategy for neutralizing GcMAF activity, iv) on the results of GcMAF clinical trials in various cancers; and will discuss the available controversies regarding the positioning of GcMAF as an effective antitumor drug. 

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.

3'-UTR Polymorphisms in the Vascular Endothelial Growth Factor Gene (VEGF) Contribute to Susceptibility to Recurrent Pregnancy Loss (RPL)

Numerous studies have examined the genetic association of vascular endothelial growth factor (VEGF) single nucleotide polymorphisms (SNPs) with recurrent pregnancy loss (RPL). However, of the four known SNPs in the 3′-untranslated region (3′-UTR) of VEGF, three SNPs—namely rs3025040 (1451C>T), rs10434 (1612G>A), and rs3025053 (1725G>A)—remain poorly characterized with regard to RPL. Herein, we evaluated the association between these three SNPs in the VEGF 3′-UTR and RPL susceptibility. We analyzed VEGF 3′-UTR gene variants in with and without RPL using TaqMan allelic discrimination. There were significant differences in the genotype frequencies of 1612G>A (GA: adjusted odds ratio (AOR), 0.652; 95% confidence interval (CI), 0.447–0.951; p = 0.026) and 1725G>A (GA: AOR, 0.503; 95% CI, 0.229–0.848; p = 0.010) in RPL patients vs. controls. Our results indicate that the 1612G>A and 1725G>A polymorphisms in the 3′-UTR of VEGF are associated with RPL susceptibility in Korean women. These data suggest that VEGF 3′-UTR polymorphisms may be utilized as biomarkers for the detection of RPL risk and prevention.

The Intersection between Tumor Angiogenesis and Immune Suppression

Both immune checkpoint inhibitors (ICI) and antiangiogenesis agents have changed the landscape of cancer treatment in the modern era. While antiangiogenesis agents have demonstrated activities in tumors with high vascularization, including renal cell carcinoma and colorectal cancer, the effect of ICIs has been seen mainly in immunologically recognized tumors, with highly immune-infiltrative lymphocytes. The main challenge in the drug development of ICIs is moving their activities to noninflamed tumors and overcoming resistance that is driven, in part, by the immune-suppressive microenvironment. Angiogenesis factors drive immune suppression by directly suppressing the antigen-presenting cells as well as immune effector cells or through augmenting the effect of regulatory T cells (Treg), myeloid-derived suppressor cells (MDSC), and tumor-associated macrophages (TAM). Those suppressive immune cells can also drive angiogenesis, creating a vicious cycle of impaired immune activation. The combination of bevacizumab and ipilimumab was the first to show the promising effect of antiangiogenesis and ICIs. A plethora of similar combinations has entered the clinic since then, confirming the promising effects of such approach.

Exploratory Study of the Effect of IMA950/Poly-ICLC Vaccination on Response to Bevacizumab in Relapsing High-Grade Glioma Patients

Immunotherapy, including therapeutic vaccines, is increasingly being developed for patients with high-grade glioma, and combinations of immunotherapies and synergy with standard of care are being investigated. In this regard, bevacizumab (BEV) has been shown to synergize with immunotherapy in preclinical studies of glioma and in other tumour entities. Here, we conducted a post-hoc exploratory study to evaluate the effect of the IMA950/poly-ICLC peptide vaccine on subsequent BEV administration in high-grade glioma patients. 16 IMA950-vaccinated and 40 non-vaccinated patients were included. At initial diagnosis, patients benefited from surgery and chemoradiation. At first or subsequent recurrence, patients received 10mg/kg of BEV every 2-3 weeks. Primary endpoints were overall survival (OS) and progression-free survival (PFS) from BEV initiation. IMA950-vaccinated patients did not show improved response to BEV as compared to non-vaccinated patients: there was no difference in median PFS (2.6 vs. 4.2 months for vaccinated and control patients, respectively, p = 0.50) nor in median OS (7.8 vs. 10.0 months for vaccinated and control patients, respectively, p = 0.69). In conclusion, potential synergy of BEV and therapeutic vaccines, when administered sequentially, has yet to be established in the clinical setting of GBM recurrence. Potential synergy of concomitant administration should be tested in future trials.

Phytochemicals Targeting VEGF and VEGF-Related Multifactors as Anticancer Therapy

The role of vascular endothelial growth factor (VEGF) in cancer cells is not limited to angiogenesis; there are also multiple factors, such as neuropilins (non-tyrosine kinases receptors), tyrosine kinases receptors, immunodeficiencies, and integrins, that interact with VEGF signaling and cause cancer initiation. By combating these factors, tumor progression can be inhibited or limited. Natural products are sources of several bioactive phytochemicals that can interact with VEGF-promoting factors and inhibit them through various signaling pathways, thereby inhibiting cancer growth. This review provides a deeper understanding of the relation and interaction of VEGF with cancer-promoting factors and phytochemicals in order to develop multi-targeted cancer prevention and treatment.

VEGF in Signaling and Disease: Beyond Discovery and Development

The discovery of vascular endothelial-derived growth factor (VEGF) has revolutionized our understanding of vasculogenesis and angiogenesis during development and physiological homeostasis. Over a short span of two decades, our understanding of the molecular mechanisms by which VEGF coordinates neurovascular homeostasis has become more sophisticated. The central role of VEGF in the pathogenesis of diverse cancers and blinding eye diseases has also become evident. Elucidation of the molecular regulation of VEGF and the transformative development of multiple therapeutic pathways targeting VEGF directly or indirectly is a powerful case study of how fundamental research can guide innovation and translation. It is also an elegant example of how agnostic discovery and can transform our understanding of human disease. This review will highlight critical nodal points in VEGF biology, including recent developments in immunotherapy for cancer and multitarget approaches in neovascular eye disease.

Checkpoint inhibitors and acute myelogenous leukemia: promises and challenges

INTRODUCTION

Immunity, for treatment of acute myelogenous leukemia (AML), has been leveraged historically in the form of allogeneic stem cell transplantation. Checkpoint inhibitors (CPI) as positive modulators of immune response have been recent major breakthroughs in solid tumors. Areas covered: Emerging concepts and clinical data with CPIs in acute Myeloid Leukemia - the focus of this review- will be discussed. CPIs can potentially be effective in absence of 'actionable' mutations and are expected to be effective against poor-risk AML. Immune inhibitory checkpoint molecules are upregulated in both de novo and relapsed AML. Similar data also suggest role of checkpoint molecules in mediating resistance particularly to hypomethylating agent (HMA) therapy, which can potentially be reversed by using checkpoint inhibitors. Expert commentary: Ongoing clinical trials in combination with HMAs are showing early promise, with doubling of response than that seen in historic controls. The optimal combinations of CPIs and the optimal space that they will fit in the continuum of AML therapies need lot of in depth work.

Multifaceted role of cancer educated platelets in survival of cancer cells

Platelets, the derivatives of megakaryocytes, pose dynamic biological functions such as homeostasis and wound healing. The mechanisms involved in these processes are utilized by cancerous cells for proliferation and metastasis. Platelets through their activation establish an aggregate termed as Tumor cell induced platelet aggregation (TCIPA) that aids in establishing a niche for the primary tumor at secondary site while recruiting granulocytes and monocytes. The study of these close interactions between the tumor and the platelets can be exploited as biomarkers in liquid biopsy for early cancer detection, thereby increasing the life expectancy of cancer patients.

Therapeutic impact of Nintedanib with paclitaxel and/or a PD-L1 antibody in preclinical models of orthotopic primary or metastatic triple negative breast cancer

BACKGROUND

Triple negative breast cancer (TNBC) is an aggressive malignancy with poor prognosis, in part because of the current lack of any approved molecularly targeted therapy. We evaluated various combinations of three different drugs: nintedanib, an antiangiogenic TKI targeting VEGF receptors, paclitaxel (PTX), or a PD-L1 antibody, using models of orthotopic primary or advanced metastatic TNBC involving a metastatic variant of the MDA-MB-231 human cell line (called LM2-4) in SCID mice and two mouse lines (EMT-6 and a drug-resistant variant, EMT-6/CDDP) in immunocompetent mice. These drugs were selected based on the following: PTX is approved for TNBC; nintedanib combined with docetaxel has shown phase III clinical trial success, albeit in NSCLC; VEGF can act as local immunosuppressive factor; and PD-L1 antibody plus taxane therapy was recently reported to have encouraging phase III trial benefit in TNBC.

METHODS

Statistical analyses were performed with ANOVA followed by Tukey's Multiple Comparison Test or with Kruskal-Wallis test followed by Dunn's Multiple Comparison Test. Survival curves were analyzed using a Log-rank (Mantel Cox) test. Differences were considered statistically significant when p values were < 0.05.

RESULTS

Toxicity analyses showed that nintedanib is well tolerated when administered 5-days ON 2-days OFF; PTX toxicity differed in mice, varied with cell lines used and may have influenced median survival in the metastatic EMT6/CDDP model; while toxicity of PD-L1 therapy depended on the cell lines and treatment settings tested. In the LM2-4 system, combining nintedanib with PTX enhanced overall antitumor efficacy in both primary and metastatic treatment settings. In immunocompetent mice, combining nintedanib or PTX with the PD-L1 antibody improved overall antitumor efficacy. Using the advanced metastatic EMT-6/CDDP model, optimal efficacy results were obtained using the triple combination.

CONCLUSIONS

These results suggest circumstances where nintedanib plus PTX may be potentially effective in treating TNBC, and nintedanib with PTX may improve PD-L1 therapy of metastatic TNBC.

Targeting Multiple Receptors to Increase Checkpoint Blockade Efficacy

Immune checkpoint blockade therapy is a powerful treatment strategy for many cancer types. Many patients will have limited responses to monotherapy targeted to a single immune checkpoint. Both inhibitory and stimulatory immune checkpoints continue to be discovered. Additionally, many receptors previously identified to play a role in tumor formation and progression are being found to have immunomodulatory components. The success of immunotherapy depends on maximizing pro-anti-tumor immunity while minimizing immunosuppressive signaling. Combining immune checkpoint targeted approaches with each other or with other receptor targets is a promising schema for future therapeutic regimen designs.

Does the Immunocompetent Status of Cancer Patients Have an Impact on Therapeutic DC Vaccination Strategies?

Although different types of therapeutic vaccines against established cancerous lesions in various indications have been developed since the 1990s, their clinical benefit is still very limited. This observed lack of effectiveness in cancer eradication may be partially due to the often deficient immunocompetent status of cancer patients, which may facilitate tumor development by different mechanisms, including immune evasion. The most frequently used cellular vehicle in clinical trials are dendritic cells (DCs), thanks to their crucial role in initiating and directing immune responses. Viable vaccination options using DCs are available, with a positive toxicity profile. For these reasons, despite their limited therapeutic outcomes, DC vaccination is currently considered an additional immunotherapeutic option that still needs to be further explored. In this review, we propose potential actions aimed at improving DC vaccine efficacy by counteracting the detrimental mechanisms recognized to date and implicated in establishing a poor immunocompetent status in cancer patients.

Harnessing the immune system in glioblastoma

Glioblastoma is the most common primary malignant brain tumour. Survival is poor and improved treatment options are urgently needed. Although immunotherapies have emerged as effective treatments for a number of cancers, translation of these through to brain tumours is a distinct challenge, particularly due to the blood-brain barrier and the unique immune tumour microenvironment afforded by CNS-specific cells. This review discusses the immune system within the CNS, mechanisms of immune escape employed by glioblastoma, and the immunological effects of conventional glioblastoma treatments. Novel therapies for glioblastoma that harness the immune system and their current clinical progress are outlined, including cancer vaccines, T-cell therapies and immune checkpoint modulators.

The associations between serum vascular endothelial growth factor, tumor necrosis factor and interleukin 4 with the markers of blood-brain barrier breakdown in patients with paraneoplastic neurological syndromes

The blood–brain barrier (BBB) disruption is a critical step in paraneoplastic neurological syndrome (PNS) development. Several cytokines have been implicated in BBB breakdown. However, the exact step-by-step mechanism in which PNS develops is unknown, and the relationship between a systemic neoplasm and BBB is multilevel. The aim of the present study was to examine serum markers of BBB breakdown (S100B protein, neuron-specific enolase, NSE) and concentrations of proinflammatory (TNF-alpha, VEGF) and anti-inflammatory/immunosuppressive cytokines (IL-4), and to establish their interrelationship in patients with PNS. We analyzed 84 patients seropositive for onconeural antibodies that originated from a cohort of 250 cases with suspected PNS. Onconeural antibodies were estimated with indirect immunofluorescence and confirmed with Western blotting. Serum S-100B was estimated using electrochemiluminescence immunoassay. NSE, VEGF, TNF-alpha and IL-4 were analyzed with ELISA. We found that S-100B protein and NSE serum concentrations were elevated in PNS patients without diagnosed malignancy, and S-100B additionally in patients with peripheral nervous system manifestation of PNS. Serum VEGF levels showed several abnormalities, including a decrease in anti-Hu positive patients and increase in PNS patients with typical manifestation and/or central nervous system involvement. Increase in TNF-alpha was observed in patients with undetermined antibodies. To conclude, the presence of paraneoplastic neurological syndrome in seropositive patients does not affect serum markers of BBB breakdown, with the exception of the group without clinically demonstrated malignancy and patients with peripheral manifestation of PNS. S-100B and NSE might increase during early phase of PNS. VEGF may be involved in typical PNS pathophysiology.

CAR T Cell Therapy for Neuroblastoma

Patients with high risk neuroblastoma have a poor prognosis and survivors are often left with debilitating long term sequelae from treatment. Even after integration of anti-GD2 monoclonal antibody therapy into standard, upftont protocols, 5-year overall survival rates are only about 50%. The success of anti-GD2 therapy has proven that immunotherapy can be effective in neuroblastoma. Adoptive transfer of chimeric antigen receptor (CAR) T cells has the potential to build on this success. In early phase clinical trials, CAR T cell therapy for neuroblastoma has proven safe and feasible, but significant barriers to efficacy remain. These include lack of T cell persistence and potency, difficulty in target identification, and an immunosuppressive tumor microenvironment. With recent advances in CAR T cell engineering, many of these issues are being addressed in the laboratory. In this review, we summarize the clinical trials that have been completed or are underway for CAR T cell therapy in neuroblastoma, discuss the conclusions and open questions derived from these trials, and consider potential strategies to improve CAR T cell therapy for patients with neuroblastoma.

Umbilical Cord Blood-Derived Natural Killer Cells Combined with Bevacizumab for Colorectal Cancer Treatment

Colorectal cancer (CRC) is among the cancers with the highest incidence globally, and it currently ranks as the fourth leading cause of cancer-related deaths worldwide. Novel strategies for the treatment of advanced CRC are urgently needed, and adoptive transfer of allogeneic natural killer (NK) cells represents an attractive option. In this study, we successfully expanded NK cells from umbilical cord blood (UCB) with membrane-bound interleukin (IL)-21, termed eUCB-NK cells. eUCB-NK cells efficiently lysed CRC cell lines in vitro and secreted significantly higher levels of interferon-γ, tumor necrosis factor-α, granulocyte-macrophage colony stimulating factor, and chemokine ligand 3 compared with IL-2-stimulated NK cells. Adoptive transfer of these NK cells significantly inhibited the growth of HT29 xenografts, whereas LoVo tumors were not effectively controlled with eUCB-NK cells. Higher numbers of NK cells inside HT29 tumors, not seen in LoVo tumors, might contribute to the differences in response to eUCB-NK cells. Bevacizumab increased extravasation of adoptively transferred NK cells into LoVo tumors and improved the therapeutic activity of eUCB-NK cells. These results justify clinical translation of UCB-derived NK cell-based therapeutics, used alone or in combination with bevacizumab, as a novel treatment option for patients with CRC.

Skin Allografting Activates Anti-tumor Immunity and Suppresses Growth of Colon Cancer in Mice

INTRODUCTION: The tumor cells could escape from the immune elimination through the immunoediting mechanisms including the generation of immunosuppressive or immunoregulative cells. By contrast, allograft transplantation could activate the immune system and induce a strong allogenic response. The aim of this study was to investigate the efficacy of allogenic skin transplantation in the inhibition of tumor growth through the activation of allogenic immune response. METHODS: Full-thickness skin transplantation was performed from C57BL/6 (H-2^b) donors to BALB/c (H-2^d) recipients that were receiving subcutaneous injection of isogenic CT26 colon cancer cells (2 × 10⁶ cells) at the same time. The tumor size and pathological changes, cell populations and cytokine profiles were evaluated at day 14 post-transplantation. RESULTS: The results showed that as compared to non-transplant group, the allogenic immune response in the skin-grafting group inhibited the growth of tumors, which was significantly associated with increased numbers of intra-tumor infiltrating lymphocytes, increased populations of CD11c⁺MHC-classII⁺CD86⁺ DCs, CD3⁺CD4⁺ T cells, CD3⁺CD8⁺ T cells, and CD19⁺ B cells, as well as decreased percentage of CD4⁺CD25⁺Foxp3⁺ T cells in the spleens. In addition, the levels of serum IgM and IgG, tumor necrosis factor (TNF)-α and interferon (IFN)-γ were significantly higher within the tumor in skin transplant groups than that in non-transplant group. CONCLUSIONS: Allogenic skin transplantation suppresses the tumor growth through activating the allogenic immune response, and it may provide a new immunotherapy option for the clinical refractory tumor treatment.

Contribution to Tumor Angiogenesis From Innate Immune Cells Within the Tumor Microenvironment: Implications for Immunotherapy

The critical role of angiogenesis in promoting tumor growth and metastasis is strongly established. However, tumors show considerable variation in angiogenic characteristics and in their sensitivity to antiangiogenic therapy. Tumor angiogenesis involves not only cancer cells but also various tumor-associated leukocytes (TALs) and stromal cells. TALs produce chemokines, cytokines, proteases, structural proteins, and microvescicles. Vascular endothelial growth factor (VEGF) and inflammatory chemokines are not only major proangiogenic factors but are also immune modulators, which increase angiogenesis and lead to immune suppression. In our review, we discuss the regulation of angiogenesis by innate immune cells in the tumor microenvironment, specific features, and roles of major players: macrophages, neutrophils, myeloid-derived suppressor and dendritic cells, mast cells, γδT cells, innate lymphoid cells, and natural killer cells. Anti-VEGF or anti-inflammatory drugs could balance an immunosuppressive microenvironment to an immune permissive one. Anti-VEGF as well as anti-inflammatory drugs could therefore represent partners for combinations with immune checkpoint inhibitors, enhancing the effects of immune therapy.