How recent advances in immunotherapy are changing the standard of care for patients with metastatic melanoma

Novel induction of CD40 expression by tumor cells with RAS/RAF/PI3K pathway inhibition augments response to checkpoint blockade

BACKGROUND

While immune checkpoint blockade (ICB) is the current first-line treatment for metastatic melanoma, it is effective for ~ 52% of patients and has dangerous side effects. The objective here was to identify the feasibility and mechanism of RAS/RAF/PI3K pathway inhibition in melanoma to sensitize tumors to ICB therapy.

METHODS

Rigosertib (RGS) is a non-ATP-competitive small molecule RAS mimetic. RGS monotherapy or in combination therapy with ICB were investigated using immunocompetent mouse models of BRAF^wt and BRAF^mut melanoma and analyzed in reference to patient data.

RESULTS

RGS treatment (300 mg/kg) was well tolerated in mice and resulted in ~ 50% inhibition of tumor growth as monotherapy and ~ 70% inhibition in combination with αPD1 + αCTLA4. RGS-induced tumor growth inhibition depends on CD40 upregulation in melanoma cells followed by immunogenic cell death, leading to enriched dendritic cells and activated T cells in the tumor microenvironment. The RGS-initiated tumor suppression was partially reversed by either knockdown of CD40 expression in melanoma cells or depletion of CD8⁺ cytotoxic T cells. Treatment with either dabrafenib and trametinib or with RGS, increased CD40⁺SOX10⁺ melanoma cells in the tumors of melanoma patients and patient-derived xenografts. High CD40 expression level correlates with beneficial T-cell responses and better survival in a TCGA dataset from melanoma patients. Expression of CD40 by melanoma cells is associated with therapeutic response to RAF/MEK inhibition and ICB.

CONCLUSIONS

Our data support the therapeutic use of RGS + αPD1 + αCTLA4 in RAS/RAF/PI3K pathway-activated melanomas and point to the need for clinical trials of RGS + ICB for melanoma patients who do not respond to ICB alone.

TRIAL REGISTRATION

NCT01205815 (Sept 17, 2010).

Enhancing clinical and immunological effects of anti-PD-1 with belapectin, a galectin-3 inhibitor

BACKGROUND

PD-1/PD-L1 engagement and overexpression of galectin-3 (Gal-3) are critical mechanisms of tumor-induced immune suppression that contribute to immunotherapy resistance. We hypothesized that Gal-3 blockade with belapectin (GR-MD-02) plus anti-PD-1 (pembrolizumab) would enhance tumor response in patients with metastatic melanoma (MM) and head and neck squamous cell carcinoma (HNSCC).

METHODS

We performed a phase I dose escalation study of belapectin+pembrolizumab in patients with advanced MM or HNSCC (NCT02575404). Belapectin was administered at 2, 4, or 8 mg/kg IV 60 min before pembrolizumab (200 mg IV every 3 weeks for five cycles). Responding patients continued pembrolizumab monotherapy for up to 17 cycles. Main eligibility requirements were a functional Eastern Cooperative Oncology Group status of 0-2, measurable or assessable disease, and no active autoimmune disease. Prior T-cell checkpoint antibody therapy was permitted.

RESULTS

Objective response was observed in 50% of MM (7/14) and and 33% of HNSCC (2/6) patients. Belapectin+pembrolizumab was associated with fewer immune-mediated adverse events than anticipated with pembrolizumab monotherapy. There were no dose-limiting toxicities for belapectin within the dose range investigated. Significantly increased effector memory T-cell activation and reduced monocytic myeloid-derived suppressor cells (M-MDSCs) were observed in responders compared with non-responders. Increased baseline expression of Gal-3+ tumor cells and PD-1+CD8+ T cells in the periphery correlated with response as did higher serum trough levels of pembrolizumab.

CONCLUSIONS

Belapectin+pembrolizumab therapy has activity in MM and HNSCC. Increased Gal-3 expression, expansion of effector memory T cells, and decreased M-MDSCs correlated with clinical response. Further investigation is planned.

Enhancing the Generation of Eomeshi CD8+ T Cells Augments the Efficacy of OX40- and CTLA-4-Targeted Immunotherapy

CTLA-4 blockade in combination with an agonist OX40-specific monoclonal antibody synergizes to augment antitumor immunity through enhanced T-cell effector function, leading to increased survival in preclinical cancer models. We have shown previously that anti-OX40/anti-CTLA-4 combination therapy synergistically enhances the expression of Eomesodermin (Eomes) in CD8⁺ T cells. Eomes is a critical transcription factor for the differentiation and memory function of CD8⁺ T cells. We hypothesized that Eomes^hiCD8⁺ T cells were necessary for anti-OX40/anti-CTLA-4 immunotherapy efficacy and that further enhancement of this population would improve tumor-free survival. Indeed, CD8⁺ T cell-specific deletion of Eomes abrogated the efficacy of anti-OX40/anti-CTLA-4 therapy. We also found that anti-OX40/anti-CTLA-4-induced Eomes^hiCD8⁺ T cells expressed lower levels of checkpoint receptors (PD1, Tim-3, and Lag-3) and higher levels of effector cytokines (IFNγ and TNFα) than their Eomes^lo counterparts. Eomes expression is negatively regulated in T cells through interleukin-2-inducible T-cell kinase (ITK) signaling. We investigated the impact of modulating ITK signaling with ibrutinib, an FDA-approved tyrosine kinase inhibitor, and found that anti-OX40/anti-CTLA-4/ibrutinib therapy further enhanced CD8⁺ T cell-specific Eomes expression, leading to enhanced tumor regression and improved survival, both of which were associated with increased T-cell effector function across multiple tumor models. Taken together, these data demonstrate the potential of anti-OX40/anti-CTLA-4/ibrutinib as a triple therapy to improve the efficacy of immunotherapy.

Abdominal CT manifestations of adverse events to immunotherapy: a primer for radiologists

Immunotherapy is a rapidly growing field within oncology and is being increasingly used in the management of several malignancies. Due to their unique mechanism of action on the immune system and neoplastic cells, the response pattern and adverse events of this novel therapy are distinct from conventional systemic therapies. Accordingly, the imaging appearances following immunotherapy including adverse events are unique and at times perplexing. Imaging is integral to management of patients on immunotherapeutic agents and a thorough understanding of its mechanism, response patterns and adverse events is crucial for precise interpretation of imaging studies. This review provides a description of the mechanism of action of current immunotherapeutic agents and the organ-wise description of their side effects.

A Quality-adjusted Time Without Symptoms or Toxicity (Q-TWiST) Analysis of Nivolumab Versus Everolimus in Advanced Renal Cell Carcinoma (aRCC)

This study assessed the net health benefits of treatment with nivolumab versus everolimus among patients with advanced renal cell carcinoma by assessing the quality (ie, patient preferences) and quantity of survival (ie, time spent with significant toxicities, in progression, or before progression and without significant toxicities). Nivolumab resulted in a 3.3-month quality-adjusted survival gain versus everolimus that was statistically significant and clearly clinically meaningful.

Imaging of Cancer Immunotherapy: Current Approaches and Future Directions

Cancer immunotherapy using immune-checkpoint inhibitors has emerged as an effective treatment option for a variety of advanced cancers in the past decade. Because of the distinct mechanisms of immunotherapy that activate the host immunity to treat cancers, unconventional immune-related phenomena are encountered in terms of tumor response and progression, as well as drug toxicity. Imaging plays an important role in objectively characterizing immune-related tumor responses and progression and in detecting and monitoring immune-related adverse events. Moreover, emerging data suggest a promise for molecular imaging that can visualize the specific target molecules involved in immune-checkpoint pathways. In this article, the background and current status of cancer immunotherapy are summarized, and the current methods for imaging evaluations of immune-related responses and toxicities are reviewed along with their limitations and pitfalls. Emerging approaches with molecular imaging are also discussed as a future direction to address unmet needs.

Metformin exerts antitumor activity via induction of multiple death pathways in tumor cells and activation of a protective immune response

The antitumor effect of metformin has been demonstrated in several types of cancer; however, the mechanisms involved are incompletely understood. In this study, we showed that metformin acts directly on melanoma cells as well as on the tumor microenvironment, particularly in the context of the immune response. In vitro, metformin induces a complex interplay between apoptosis and autophagy in melanoma cells. The anti-metastatic activity of metformin in vivo was assessed in several mouse models challenged with B16F10 cells. Metformin's activity was, in part, immune system-dependent, whereas its antitumor properties were abrogated in immunodeficient (NSG) mice. Metformin treatment increased the number of lung CD8-effector-memory T and CD4⁺Foxp3⁺IL-10⁺ T cells in B16F10-transplanted mice. It also decreased the levels of Gr-1⁺CD11b⁺ and RORγ⁺ IL17⁺CD4⁺ cells in B16F10-injected mice and the anti-metastatic effect was impaired in RAG-1^−/− mice challenged with B16F10 cells, suggesting an important role for T cells in the protection induced by metformin. Finally, metformin in combination with the clinical metabolic agents rapamycin and sitagliptin showed a higher antitumor effect. The metformin/sitagliptin combination was effective in a BRAFV600E/PTEN tamoxifen-inducible murine melanoma model. Taken together, these results suggest that metformin has a pronounced effect on melanoma cells, including the induction of a strong protective immune response in the tumor microenvironment, leading to tumor growth control, and the combination with other metabolic agents may increase this effect.

Reversal of Resistance in Targeted Therapy of Metastatic Melanoma: Lessons Learned from Vemurafenib (BRAFV600E-Specific Inhibitor)

Malignant melanoma is the most aggressive form of skin cancer and has a very low survival rate. Over 50% of melanomas harbor various BRAF mutations with the most common being the V600E. BRAF^V600E mutation that causes constitutive activation of the MAPK pathway leading to drug-, immune-resistance, apoptosis evasion, proliferation, survival, and metastasis of melanomas. The ATP competitive BRAF^V600E selective inhibitor, vemurafenib, has shown dramatic success in clinical trials; promoting tumor regression and an increase in overall survival of patients with metastatic melanoma. Regrettably, vemurafenib-resistance develops over an average of six months, which renders melanomas resistant to other therapeutic strategies. Elucidation of the underlying mechanism(s) of acquisition of vemurafenib-resistance and design of novel approaches to override resistance is the subject of intense clinical and basic research. In this review, we summarize recent developments in therapeutic approaches and clinical investigations on melanomas with BRAF^V600E mutation to establish a new platform for the treatment of melanoma.

Ipilimumab in the Treatment of Metastatic Melanoma: A Summary of Recent Studies

In the last 20 years, the survival and quality of life outcomes for patients with metastatic melanoma have been poor, with unsatisfactory results of chemotherapy and immunotherapy-based regimens. No drug or combination of drugs had any impact on survival until 2011, when ipilimumab, a monoclonal antibody against cytotoxic T-lymphocyte antigen-4 (CTLA-4), was approved for clinical use. Phase III trials have shown, for the first time ever, an overall survival benefit of ipilimumab compared with standard treatment, with a manageable toxicity profile. This review will discuss the mechanism of action of ipilimumab and the clinical trials that led to its approval.

Targeted Therapies for Melanoma Brain Metastases

Brain metastases are a major clinical challenge occurring in up to 60% of patients suffering from metastatic melanoma. They cause significant clinical symptoms and impair the overall survival prognosis. The introduction of targeted therapies including BRAF and MEK inhibitors as well as CTLA-4 and PD-1 axis targeting immune checkpoint inhibitors have dramatically improved the treatment and prognosis of patients with extracranial metastatic melanoma. Although, similar response rates for extra- and intracranial metastases have been reported, only few data from brain metastasis specific trails are available so far. The following review will provide an overview on the currently available data on targeted therapies, remaining questions and the most important side effects in the special clinical situation of melanoma brain metastases.

Inflammatory regulation of stem-like cells in melanoma

The link between inflammation, immunity and cancer is well established. In the last decade, there has been considerable excitement over cancer stem cells, believed to be a subset of tumour cells responsible for their initiation, propagation and resistance to conventional chemoradiotherapy. In this review, we discuss the characterization of cancer stem cells and describe their modulation by inflammation with a focus on melanoma.

Dacarbazine in combination with bevacizumab for the treatment of unresectable/metastatic melanoma: a phase II study

The combined treatment of dacarbazine with an antiangiogenic drug such as bevacizumab may potentiate the therapeutic effects of dacarbazine in metastatic melanoma (MM). Preliminary antitumour activity of dacarbazine plus bevacizumab is evaluated, together with the toxicity and safety profile, in MM patients. This prospective, open-label, phase II study included patients with previously untreated MM or unresectable melanoma. Patients received dacarbazine and bevacizumab until progressive disease or unacceptable toxicity. The primary efficacy variable was the overall response rate. The secondary efficacy parameters included duration of response, duration of stable disease, time to progression/progression-free survival, time to treatment failure and overall survival. The safety analysis included recordings of adverse events and exposure to study treatment. The intention-to-treat population included 37 patients (24 men and 13 women, mean age 54.2±13.1 years). Overall response rate was 18.9% (seven patients achieved a response) and clinical benefit was 48.6%. In patients who achieved a response, the median duration of response was 16.9 months and the median duration of stable disease was 12.5 months. The median time to progression/progression-free survival and time to treatment failure were 5.5 and 3.1 months, respectively. The median overall survival was 11.4 months. Almost all patients (94.6%) experienced at least one adverse event; however, no new area of toxicity of bevacizumab emerged. The dacarbazine/bevacizumab combination provides benefits compared with dacarbazine monotherapy in historical controls, with an acceptable safety profile. This combination appears to be a valid option in specific subgroups of patients, namely, those triple negative (BRAF, C-KIT and NRAS wild type) or with a BRAF mutation who have already received, or are not eligible for, immunomodulating or targeted agents.

Checkpoint Blockade for the Treatment of Advanced Melanoma

Immunotherapy with immune checkpoint inhibition has been improving the outcomes of patients with many different types of malignancies. Immune checkpoint inhibition has been most extensively studied in patients with advanced melanoma and there are three FDA approved antibodies already widely used in clinical practice (ipilimumab, nivolumab, and pembrolizumab). In this chapter, we review the mechanistic basis behind the development of immune checkpoint blocking antibodies. We then discuss specifics regarding each agent, unique clinical considerations in treating patients with this approach, and future directions, including combination strategies. This chapter is focused on melanoma, but the principles related to this immunotherapy approach are applicable to patients with many types of malignancies.

Vemurafenib for the treatment of BRAF mutant metastatic melanoma

Vemurafenib was the first selective BRAF inhibitor licensed in cancer. It is indicated for the treatment of patients affected by advanced melanoma with BRAF V600 mutation. It has shown successful results in terms of efficacy together with a favorable toxicity profile. Other compounds such as the BRAF inhibitor dabrafenib and the immunotherapeutic agent ipilimumab are also approved in the same group of patients. This article reviews the chemistry, pharmacokinetics, pharmacodynamics and clinical development of vemurafenib. Moreover, its efficacy and toxicity are compared with dabrafenib and ipilimumab. A number of trials with vemurafenib alone or in combination with other drugs are also analyzed. These trials will determine the role of vemurafenib in the treatment of BRAF mutant melanoma in forthcoming years.

Prospects of immune checkpoint modulators in the treatment of glioblastoma

Glioblastoma is the most common primary brain tumour in adults. Prognosis is poor: even with the current gold-standard first-line treatment—maximal safe resection and combination of radiotherapy with temozolomide chemotherapy—the median overall survival time is only approximately 15-17 months, because the tumour recurs in virtually all patients, and no commonly accepted standard treatment for recurrent disease exists. Several targeted agents have failed to improve patient outcomes in glioblastoma. Immunotherapy with immune checkpoint inhibitors such as ipilimumab, nivolumab, and pembrolizumab has provided relevant clinical improvements in other advanced tumours for which conventional therapies have had limited success, making immunotherapy an appealing strategy in glioblastoma. This Review summarizes current knowledge on immune checkpoint modulators and evaluates their potential role in glioblastoma on the basis of preclinical studies and emerging clinical data. Furthermore, we discuss challenges that need to be considered in the clinical development of drugs that target immune checkpoint pathways in glioblastoma, such as specific properties of the immune system in the CNS, issues with radiological response assessment, and potential interactions with established and emerging treatment strategies.

The future of targeted therapies for brain metastases

Brain metastases (BM) are an increasing challenge in the management of patients with advanced cancer. Treatment options for BM are limited and mainly focus on the application of local therapies. Systemic therapies including targeted therapies are only poorly investigated, as patients with BM were frequently excluded from clinical trials. Several targeted therapies have shown promising activity in patients with BM. In the present review we discuss existing and emerging targeted therapies for the most frequent BM primary tumor types. We focus on challenges in the conduction of clinical trials on targeted therapies in BM patients such as patient selection, combination with radiotherapy, the obstacles of the blood–brain barrier and the definition of study end points.

Immune evasion in cancer: Mechanistic basis and therapeutic strategies

Cancer immune evasion is a major stumbling block in designing effective anticancer therapeutic strategies. Although considerable progress has been made in understanding how cancers evade destructive immunity, measures to counteract tumor escape have not kept pace. There are a number of factors that contribute to tumor persistence despite having a normal host immune system. Immune editing is one of the key aspects why tumors evade surveillance causing the tumors to lie dormant in patients for years through "equilibrium" and "senescence" before re-emerging. In addition, tumors exploit several immunological processes such as targeting the regulatory T cell function or their secretions, antigen presentation, modifying the production of immune suppressive mediators, tolerance and immune deviation. Besides these, tumor heterogeneity and metastasis also play a critical role in tumor growth. A number of potential targets like promoting Th1, NK cell, γδ T cell responses, inhibiting Treg functionality, induction of IL-12, use of drugs including phytochemicals have been designed to counter tumor progression with much success. Some natural agents and phytochemicals merit further study. For example, use of certain key polysaccharide components from mushrooms and plants have shown to possess therapeutic impact on tumor-imposed genetic instability, anti-growth signaling, replicative immortality, dysregulated metabolism etc. In this review, we will discuss the advances made toward understanding the basis of cancer immune evasion and summarize the efficacy of various therapeutic measures and targets that have been developed or are being investigated to enhance tumor rejection.

Cancer immunotherapy and immune-related response assessment: The role of radiologists in the new arena of cancer treatment

The recent advances in the clinical application of anti-cancer immunotherapeutic agents have opened a new arena for the treatment of advanced cancers. Cancer immunotherapy is associated with a variety of important radiographic features in the assessments of tumor response and immune-related adverse events, which calls for radiologists' awareness and in-depth knowledge on the topic. This article will provide the state-of-the art review and perspectives of cancer immunotherapy, including its molecular mechanisms, the strategies for immune-related response assessment on imaging and their pitfalls, and the emerging knowledge of radiologic manifestations of immune-related adverse events. The cutting edge clinical and radiologic investigations are presented to provide future directions.

Blinded by the light: why the treatment of metastatic melanoma has created a new paradigm for the management of cancer

Until recently, treatment for metastatic melanoma was characterised by a limited availability of treatment options that offer objective survival benefit. Cytotoxic agents fundamentally lack the ability to achieve disease control and cytokine therapy with interleukin-2 has an unacceptably high - for the use across all patient cohorts - rate of toxicities. The validation of braf as an oncogene driving melanoma tumorigenesis, as well as the discovery of the role of CTLA-4 receptor in the evasion of anticancer immune response by melanoma, has revolutionised our treatment options against a disease with dismal prognosis. Quick implementation of translational discoveries brought about BRAF/MEK inhibition in clinic, while at the same time, wider experience with CTLA-4 blockade enabled clinicians to manage previously fatal immune-related toxicities with greater confidence. The suitability for clinical use of other oncogenic drivers such as NRAS and c-kit is currently being tested whilst the PD-1/PD-L1/PD-L2 axis has emerged as a new immunotherapy target with exciting early phase results. The recent exponential progress in treatment of melanoma has set an example of translational medicine and the current review aims to explain why, as well as suggesting new goals for the future.

Cost-effectiveness of therapies for melanoma

Melanoma presents an important burden worldwide. Until recently, the prognosis for unresectable and metastatic melanoma was poor, with 10% of metastatic melanoma patients surviving for 2 years. The introduction of newer therapies including ipilimumab, vemurafenib, dabrafenib and trametinib improved progression-free survival, with additional benefits anticipated from the forthcoming class of programmed cell death 1 inhibitors. Cost of therapy and resulting cost-effectiveness is an important factor in determining patient access to specific treatments. The objective of this study was to review the published evidence regarding cost-effectiveness of melanoma therapies and provide an overview of the relative cost-effectiveness of available therapies by disease stage. For earlier-stage disease, IFN-α has been found to be cost-effective, although its clinical benefits have not been well established. For unresectable and metastatic melanoma, newer therapies provide benefits over standard-of-care chemotherapy, but comprehensive analyses will need to be conducted to determine the most cost-effective therapy.

Ipilimumab for the treatment of melanoma

Melanoma is the sixth most common cancer in the US. Metastatic melanoma has increased in incidence over the past 30 years. In the US approximately 8600 people died from melanoma in 2009. It is an aggressive tumor; the prognosis of stage IV is poor. Before 2011, only dacarbazine and IL-2 were approved for metastatic melanoma. Major advances have been made in understanding the genetic profile, molecular factors that drive malignant transformation and the role of T cells in melanoma patients. Immune regulatory pathways affecting immune responses to cancer are becoming better defined. Cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) downregulates the pathways of T-cell activation. Ipilimumab is an anti CTLA-4 monoclonal antibody approved in 2011 to treat metastatic or unresectable melanoma.

Therapeutic cancer vaccines: a long and winding road to success

Harnessing the immune system to achieve therapeutic efficacy in cancer has been a milestone in immuno-oncology. Tumor-induced suppression works as an obstacle for the effectiveness of immunotherapies. Advances in our understanding of the interrelationship between cancer immunoediting and immunotherapy led to successful manipulation of anticancer immunity; this provided the platform for combining cancer vaccines with chemotherapies counteracting, to some extent, tumor-induced suppressive entities and demonstrating clinical efficacy. Targeting co-inhibitory and co-stimulatory receptors with immunostimulatory antibodies has also shown clinical promise and its combined use with vaccines is a promising new approach of immunotherapy for cancer. Recent evidence supporting vaccine administration in patients with early and less aggressive disease should be additionally placed to select the appropriate patient population and to identify earlier markers of clinical benefit and immunological parameters that correlate with survival. This review focuses on promising vaccination platforms and essential perspectives in the treatment of cancer.

Immunotherapy advances for glioblastoma

Survival for patients with glioblastoma, the most common high-grade primary CNS tumor, remains poor despite multiple therapeutic interventions including intensifying cytotoxic therapy, targeting dysregulated cell signaling pathways, and blocking angiogenesis. Exciting, durable clinical benefits have recently been demonstrated for a number of other challenging cancers using a variety of immunotherapeutic approaches. Much modern research confirms that the CNS is immunoactive rather than immunoprivileged. Preliminary results of clinical studies demonstrate that varied vaccine strategies have achieved encouraging evidence of clinical benefit for glioblastoma patients, although multiple variables will likely require systematic investigation before optimal outcomes are realized. Initial preclinical studies have also revealed promising results with other immunotherapies including cell-based approaches and immune checkpoint blockade. Clinical studies to evaluate a wide array of immune therapies for malignant glioma patients are being rapidly developed. Important considerations going forward include optimizing response assessment and identifiying correlative biomarkers for predict therapeutic benefit. Finally, the potential of complementary combinatorial immunotherapeutic regimens is highly exciting and warrants expedited investigation.

A phase I dose escalation trial of tremelimumab (CP-675,206) in combination with gemcitabine in chemotherapy-naive patients with metastatic pancreatic cancer

BACKGROUND

Tremelimumab (CP-675,206) is a fully human monoclonal antibody binding to cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) on T cells that stimulates the immune system by blocking the CTLA4-negative regulatory signal. Combination with standard chemotherapy may strengthen antitumor therapy. This is a phase Ib, multisite, open-label, nonrandomized dose escalation trial evaluating the safety, tolerability, and maximum tolerated dose (MTD) of tremelimumab combined with gemcitabine in patients with metastatic pancreatic cancer.

PATIENTS AND METHODS

Gemcitabine (1000 mg/m(2) on days 1, 8, and 15 of each 28-day cycles) was administrated with escalating doses of i.v. tremelimumab (6, 10, or 15 mg/kg) on day 1 of each 84-day cycle for a maximum of 4 cycles. The first 18 patients had an initial 4-week gemcitabine-only lead-in period. Dose-limiting toxicities (DLTs) related to tremelimumab were evaluated during the first 6 weeks after the first dose of tremelimumab.

RESULTS

From June 2008 to August 2011, 34 patients were enrolled and received at least one dose of tremelimumab. No DLTs related to tremelimumab were observed at any dose, even when the maximum dose established for tremelimumab (15 mg/kg) was used. Most frequent grade 3/4 toxicities were asthenia (11.8%) and nausea (8.8%). Only one patient had a serious drug-related event (diarrhea with dehydration). The median overall survival was 7.4 months (95% confidence interval 5.8-9.4 months). At the end of treatment, two patients achieved partial response. Both patients received tremelimumab 15-mg/kg group (n = 2/19, 10.5%).

CONCLUSION

Tremelimumab plus gemcitabine demonstrated a safety and tolerability profile, warranting further study in patients with metastatic pancreatic cancer.

CLINICALTRIALSGOV ID

NCT00556023.

Checkpoint modulation in melanoma: an update on ipilimumab and future directions

Ipilimumab, an anti-cytotoxic T-lymphocyte antigen 4 antibody, was the first therapy demonstrated to improve overall survival in melanoma. Since ipilimumab's approval by the FDA in 2011, a wealth of data has amassed, helping clinicians to optimize its use. We have learned how to mitigate the adverse effects of ipilimumab, identified its effects in melanoma subpopulations such as those with brain metastases, uveal melanoma, and mucosal melanoma, discovered potential biomarkers of activity, and investigated its use in combination with other therapeutic modalities. These discoveries have paved the way for rapid development of second-generation immunomodulatory antibodies such as inhibitors of the programmed cell death 1 receptor axis. These new agents hold promise as monotherapy, but perhaps the greatest allure lies in the possibility of combining these agents in synergistic multidrug regimens.

Adenosine limits the therapeutic effectiveness of anti-CTLA4 mAb in a mouse melanoma model

Combination therapies for melanoma that target immune-regulatory networks are entering clinical practice, and more are under investigation in preclinical or clinical studies. Adenosine plays a key role in regulating melanoma progression. We investigated the effectiveness of cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) antibody (mAb) in combination with either modulators of adenosine receptors (AR) activation or an inhibitor of adenosine production in a murine model of melanoma. We found that treatment with APCP, selective inhibitor of the adenosine-generating nucleotidase CD73, enhanced the activity of anti-CTLA4 mAb, by improving tumor immune response. Blockade of the adenosine A2a receptor (A2aR), which plays a critical role in the regulation of T-cell functions, significantly reduced melanoma growth. Most importantly, combination therapy including an A2aR antagonist with anti-CTLA4 mAb markedly inhibited tumor growth and enhanced anti-tumor immune responses. Targeting A3R and CTLA4 was not as effective in limiting melanoma growth as targeting A2aR. These data suggest that the efficacy of anti-CTLA4 melanoma therapy may be improved by targeting multiple mechanisms of immune suppression within tumor tissue, including CD73 or A2a receptor.

Targeted therapy for non-small-cell lung cancer: past, present and future

Therapy for advanced non-small-cell lung cancer has developed significantly with new awareness of histologic subtype as an important factor in guiding treatment and the development of targeted agents for molecular subgroups harboring critical mutations that spur on cancer growth. In this comprehensive review, we look back at developments in targeted therapy for advanced non-small-cell lung cancer, reviewing in detail efforts, both successful and in some cases less so, to target EGFR, VEGF and ALK. This review provides an overview of where the field stands at present and the areas we feel are most likely to provide challenges and potential successes in the next 5 years including immune checkpoint inhibition, epigenetic therapy and driver mutation targeting.

Metastatic melanoma to the upper aerodigestive tract: a systematic review of the literature

This study is a systematic review of the literature that was performed to clarify the natural history and treatment outcomes of upper aerodigestive tract metastases from cutaneous melanoma. A search of the MEDLINE database was undertaken from 1950 to 2013 to identify relevant manuscripts for this review. Article inclusion required cases with documentation of previous cutaneous melanoma primary lesions, adequate survival data, and description of metastatic treatment. Individual patient data were extracted from source articles for analysis of survival outcomes. A systematic search revealed 34 relevant articles with 37 cases for inclusion. Metastases were identified throughout the upper aerodigestive tract with a predilection for the oropharynx, larynx, and oral cavity. Treatment outcomes were estimated with the Kaplan-Meier method, with survival of 37% and 16% at 1 and 5 years, respectively. As expected from previous reports, 73% presented with disseminated disease burden with almost universally poor prognosis despite locoregional or systemic therapy. Conversely, a group of patients with limited metastatic burden had improved treatment response with a 1-year survival of 90%, denoting a hazard ratio of 9.7332 (95% confidence interval, 4.5-21.1) for disseminated disease in comparison. Upper aerodigestive tract metastases of melanoma thus are rare clinical entities that in general present in the setting of disseminated disease and evidently necessitate a focus on palliation. In contrast, for those with a limited metastatic burden, aggressive multimodality therapy including complete metastectomy can produce a significant survival advantage.

Distinct host cell fates for human malignant melanoma targeted by oncolytic rodent parvoviruses

The rodent parvoviruses are known to be oncoselective, and lytically infect many transformed human cells. Because current therapeutic regimens for metastatic melanoma have low response rates and have little effect on improving survival, this disease is a prime candidate for novel approaches to therapy, including oncolytic parvoviruses. Screening of low-passage, patient-derived melanoma cell lines for multiplicity-dependent killing by a panel of five rodent parvoviruses identified LuIII as the most melanoma-lytic. This property was mapped to the LuIII capsid gene, and an efficiently melanoma tropic chimeric virus shown to undergo three types of interaction with primary human melanoma cells: (1) complete lysis of cultures infected at very low multiplicities; (2) acute killing resulting from viral protein synthesis and DNA replication, without concomitant expansion of the infection, due to failure to export progeny virions efficiently; or (3) complete resistance that operates at an intracellular step following virion uptake, but preceding viral transcription.

Immune modulation in cancer with antibodies

Ipilimumab is the prototypical immunomodulatory antibody, approved by the FDA in 2011 for advanced melanoma on the basis of survival benefit. Since that time, we have made significant strides in optimizing this therapy: we have characterized the spectrum of immune-related adverse events and learned how to mitigate them with treatment algorithms, discovered potential biomarkers of activity, and identified the potential synergy between checkpoint modulation and other therapeutic modalities. Recent phase I trials have established the efficacy and safety of next-generation checkpoint agents, including PD-1 and PD-L1 inhibitors, across multiple tumor types. Much work lies ahead in developing these next-generation checkpoint agents, testing them in combination, and determining how to integrate them into the treatment paradigms of various tumor types.

Immunotherapy of melanoma with the immune costimulatory monoclonal antibodies targeting CD137

Knowledge of how the immune system recognizes and attempts to control cancer growth and development has improved dramatically. The advent of immunotherapies for cancer has resulted in robust clinical responses and confirmed that the immune system can significantly inhibit tumor progression. Until recently, metastatic melanoma was a disease with limited treatment options and a poor prognosis. CD137 (also known as 4-1BB) a member of the tumor necrosis factor (TNF) receptor superfamily, is an activation-induced T cell costimulator molecule. Growing evidence indicates that anti-CD137 monoclonal antibodies possess strong antitumor properties, the result of their powerful capability to activate CD8+ T cells, to produce interferon (IFN)-γ, and to induce cytolytic markers. Combination therapy of anti-CD137 with other anticancer agents, such as radiation, has robust tumor-regressing abilities against nonimmunogenic or poorly immunogenic tumors. Of importance, targeting CD137 eliminates established tumors, and the fact that anti-CD137 therapy acts in concert with other anticancer agents and/or radiation therapy to eradicate nonimmunogenic and weakly immunogenic tumors is an additional benefit. Currently, BMS-663513, a humanized anti-CD137 antibody, is in clinical trials in patients with solid tumors, including melanoma, renal carcinoma, ovarian cancer, and B-cell malignancies. In this review, we discuss the basis of the therapeutic potential of targeting CD137 in cancer treatment, focusing in particular, on BMS-663513 as an immune costimulatory monoclonal antibody for melanoma immunotherapy.

CTLA-4 blockade and the renaissance of cancer immunotherapy

Cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) plays a key role in restraining the adaptive immune response of T-cells towards a variety of antigens including tumor associated antigens (TAAs). The blockade of this immune checkpoint elicits an effective anticancer immune response in a range of preclinical models, suggesting that naturally occurring (or therapeutically induced) TAA specific lymphocytes need to be "unleashed" in order to properly fight against malignant cells. Therefore, investigators have tested this therapeutic hypothesis also in humans: the favorable results obtained with this strategy in patients with advanced cutaneous melanoma are revolutionizing the management of this highly aggressive disease and are fueling new enthusiasm on cancer immunotherapy in general. Here we summarize the biology of CTLA-4, overview the experimental data supporting the rational for targeting CTLA-4 to treat cancer and review the main clinical findings on this novel anticancer approach. Moreover, we critically discuss the current challenges and potential developments of this promising field of cancer immunotherapy.

At the bedside: CTLA-4- and PD-1-blocking antibodies in cancer immunotherapy

It is increasingly appreciated that cancers are recognized by the immune system, and under some circumstances, the immune system may control or even eliminate tumors. The modulation of signaling via coinhibitory or costimulatory receptors expressed on T cells has proven to be a potent way to amplify antitumor immune responses. This approach has been exploited successfully for the generation of a new class of anticancer therapies, "checkpoint-blocking" antibodies, exemplified by the recently FDA-approved agent, ipilimumab, an antibody that blocks the coinhibitory receptor CTLA-4. Capitalizing on the success of ipilimumab, agents that target a second coinhibitory receptor, PD-1, or its ligand, PD-L1, are in clinical development. Lessons learned from treating patients with CTLA-4 and PD-1 pathway-blocking antibodies will be reviewed, with a focus on concepts likely to inform the clinical development and application of agents in earlier stages of development. See related review At the bench: Preclinical rationale for CTLA-4 and PD-1 blockade as cancer immunotherapy.

Update on the Epidemiology of Melanoma

Cutaneous malignant melanoma (CMM) has been increasing steadily in incidence over the past 30 years. Recent studies have explored associations between CMM and varying physiologic risk factors, such as nevi or hair and eye color, in addition to historical features such as a personal history of nonmelanoma skin cancer (NMSC), childhood cancers, Parkinson's Disease, hormone exposure and family history of CMM. Genome-wide association studies have also uncovered many genetic determinants of CMM risk. Ultimately, ultraviolet (UV) radiation exposure remains the most important modifiable risk factor for CMM. Organ transplant recipients, and nonsteroidal anti-inflammatory usage may also play a role. While risk factors are important to identify, effective campaigns to reduce the burden of disease through early detection and prevention are essential. We present detailed data regarding these facets of care for the CMM patient, and provide an update on the epidemiology of CMM.