Ipilimumab and fotemustine in patients with advanced melanoma (NIBIT-M1): an open-label, single-arm phase 2 trial

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.

Clinical Management of Multiple Melanoma Brain Metastases: A Systematic Review

IMPORTANCE

The treatment of multiple brain metastases (MBM) from melanoma is controversial and includes surgical resection, stereotactic radiosurgery (SRS), and whole-brain radiation therapy (WBRT). Several new classes of agents have revolutionized the treatment of metastatic melanoma, allowing some subsets of patients to have long-term survival. Given this, management of MBM from melanoma is continually evolving.

OBJECTIVE

To review the current evidence regarding the treatment of MBM from melanoma.

EVIDENCE REVIEW

The PubMed database was searched using combinations of search terms and synonyms for melanoma, brain metastases, radiation, chemotherapy, immunotherapy, and targeted therapy published between January 1, 1995, and January 1, 2015. Articles were selected for inclusion on the basis of targeted keyword searches, manual review of bibliographies, and whether the article was a clinical trial, large observational study, or retrospective study focusing on melanoma brain metastases. Of 2243 articles initially identified, 110 were selected for full review. Of these, the most pertinent 73 articles were included.

FINDINGS

Patients with newly diagnosed MBM can be treated with various modalities, either alone or in combination. Level 1 evidence supports the use of SRS alone, WBRT, and SRS with WBRT. Although the addition of WBRT to SRS improves the overall brain relapse rate, WBRT has no significant impact on overall survival and has detrimental neurocognitive outcomes. Cytotoxic chemotherapy has largely been ineffective; targeted therapies and immunotherapies have been reported to have high response rates and deserve further attention in larger clinical trials. Further studies are needed to fully evaluate the efficacy of these novel regimens in combination with radiation therapy.

CONCLUSIONS AND RELEVANCE

At this time, the standard management for patients with MBM from melanoma includes SRS, WBRT, or a combination of both. Emerging data exist to support the notion that SRS in combination with targeted therapies or immune therapy may obviate the need for WBRT; prospective studies are required to fully evaluate the efficacy of these novel regimens in combination with radiation therapy.

Management of melanoma brain metastases

Relapses in the brain remain a major obstacle to cure in many patients with advanced melanoma. At present, the management of melanoma brain metastases continues to rely heavily on surgical and radiotherapeutic interventions, which have become safer and more effective with modern imaging, surgery and radiation technologies. Additionally, novel targeted and immunotherapeutic agents, shown to generate meaningful intracranial response and survival benefit in patients with melanoma brain metastases when compared with historical controls, expand systemic treatment options for this subset of patients. These systemic therapies become particularly important when intracranial disease burden precludes neuro- or radio-surgery. Considerable multidisciplinary research effort is ongoing to improve outcomes for melanoma patients with brain metastases, a key challenge in the management of advanced melanoma.

Systemic therapy of brain metastases

Brain metastases are a common complication of cancer and continue to be associated with a poor prognosis. Management of brain metastases typically requires a multidisciplinary approach which may include whole-brain radiation therapy, stereotactic radiosurgery, surgery, and systemic therapy. Historically, the use of systemic therapy in brain metastases has been challenging because of the resistance to conventional chemotherapies secondary to the blood-brain barrier and an often heavily pre-treated patient population, and the paucity of well-conducted randomized trials in these heterogeneous patient populations. Newer agents, including immunotherapy and targeted therapies, are playing increasingly important roles in the up-front management of brain metastases. In this overview, we review recent advances in systemic therapies for brain metastases and the evidence supporting their use in this patient population.

Immune Effects of Chemotherapy, Radiation, and Targeted Therapy and Opportunities for Combination With Immunotherapy

There have been significant advances in cancer treatment over the past several years through the use of chemotherapy, radiation therapy, molecularly targeted therapy, and immunotherapy. Despite these advances, treatments such as monotherapy or monomodality have significant limitations. There is increasing interest in using these strategies in combination; however, it is not completely clear how best to incorporate molecularly targeted and immune-targeted therapies into combination regimens. This is particularly pertinent when considering combinations with immunotherapy, as other types of therapy may have significant impact on host immunity, the tumor microenvironment, or both. Thus, the influence of chemotherapy, radiation therapy, and molecularly targeted therapy on the host anti-tumor immune response and the host anti-host response (ie, autoimmune toxicity) must be taken into consideration when designing immunotherapy-based combination regimens. We present data related to many of these combination approaches in the context of investigations in patients with melanoma and discuss their potential relationship to management of patients with other tumor types. Importantly, we also highlight challenges of these approaches and emphasize the need for continued translational research.

Assessing a novel immuno-oncology-based combination therapy: Ipilimumab plus electrochemotherapy

Melanoma is responsible for most skin cancer-related deaths and is one of the most common cancers diagnosed in young adults. In melanoma, tumors can become established by activation of the negative regulator of cytotoxic T lymphocytes (CTLs), CTL antigen-4 (CTLA-4). Ipilimumab blocks the interaction of CTLA-4 with CD80/CD86 and augments T-cell activation and proliferation. In electrochemotherapy (ECT), local application of short high-voltage pulses renders cell membranes transiently permeable to chemotherapeutic drugs. The combination of ipilimumab and ECT may be beneficial for the treatment of metastatic melanoma; however, no prospective data are available to date. Here, we report the retrospective analysis of patients treated with ipilimumab in an expanded access program (EAP) who also received ECT. Fifteen patients with previously treated metastatic melanoma who received ipilimumab 3 mg/kg every three weeks for four cycles and underwent ECT for local disease control and/or palliation of cutaneous lesions with bleomycin 15 mg/m2 after the first ipilimumab infusion were included in the analysis. Over the study period, a local objective response was observed in 67% of patients (27% complete response [CR] and 40% partial response [PR]). According to immune-related response criteria, a systemic response was observed in nine patients (five PR and four stable disease [SD]), resulting in a disease control rate of 60%. Evaluation of circulating T-regulatory (T-reg) cells demonstrated significant differences between responders and non-responders. Overall, treatment was well-tolerated and without notable toxicity. In conclusion, the combination of ipilimumab and ECT appears to be beneficial to patients with advanced melanoma, warranting further investigation in prospective trials.

Two heads better than one? Ipilimumab immunotherapy and radiation therapy for melanoma brain metastases

Melanoma is an aggressive malignancy with a deplorable penchant for spreading to the brain. While focal therapies such as surgery and stereotactic radiosurgery can help provide local control, the majority of patients still develop intracranial progression. Novel therapeutic combinations to improve outcomes for melanoma brain metastases (MBM) are clearly needed. Ipilimumab, the anticytotoxic T-lymphocyte-associated antigen 4 monoclonal antibody, has been shown to improve survival in patients with metastatic melanoma, but many of these trials either excluded or had very few patients with MBM. This article will review the efficacy and limitations of ipilimumab therapy for MBM, describe the current evidence for combining ipilimumab with radiation therapy, illustrate potential mechanisms for synergy, and discuss emerging clinical trials specifically investigating this combination in MBM.

Integrating Immune Checkpoint Blockade with Anti-Neo/Mutated Antigens Reactivity to Increase the Clinical Outcome of Immunotherapy

Antibodies to immune checkpoints have entered the clinical arena and have been shown to provide a clinical benefit for metastatic melanoma and, possibly, for other tumors as well. In this review paper we summarize this therapeutic activity and underline the functional mechanisms that may be involved. Among them, we discuss the so far neglected role of tumor-associated antigens (TAAs) deriving from tumor somatic mutations and summarize the results of recent trials showing the immunogenic strength of such TAAs which can be specifically targeted by T cells activated by immune checkpoint antibodies. Finally we discuss new immunotherapy approaches that involve the combination of self/shared- or neo-TAAs-based vaccines and immune checkpoint blockade antibodies, to increase the clinical response of metastatic melanoma patients.

Unsanctifying the sanctuary: challenges and opportunities with brain metastases

While the use of targeted therapies, particularly radiosurgery, has broadened therapeutic options for CNS metastases, patients respond minimally and prognosis remains poor. The inability of many systemic chemotherapeutic agents to penetrate the blood-brain barrier (BBB) has limited their use and allowed brain metastases to become a burgeoning clinical challenge. Adequate preclinical models that appropriately mimic the metastatic process, the BBB, and blood-tumor barriers (BTB) are needed to better evaluate therapies that have the ability to enhance delivery through or penetrate into these barriers and to understand the mechanisms of resistance to therapy. The heterogeneity among and within different solid tumors and subtypes of solid tumors further adds to the difficulties in determining the most appropriate treatment approaches and methods of laboratory and clinical studies. This review article discusses therapies focused on prevention and treatment of CNS metastases, particularly regarding the BBB, and the challenges and opportunities these therapies present.

Present and future of immune checkpoint blockade: Monotherapy to adjuvant approaches

Immune regulation of aggressive tumor growth is often outpaced by tumor up-regulation of ligands that inhibit effector immune responses through the activation of immune checkpoints. A few of such checkpoints include programmed death-1 (PD-1), cytotoxic T lymphocyte associated antigen-4 (CTLA-4), lymphocyte activation gene-3, T-cell immunoglobulin and mucin protein-3, Glucocorticoid-induced TNFR family-related receptor (GITR), and killer cell immunoglobulin like receptor. With the exception of GITR, after binding to their respective ligands these checkpoints induce down-modulation of immune responses to prevent autoimmunity. However, such immune mechanisms are co-opted by tumors to allow rapid tumor cell proliferation. Pre-clinical studies in antibody blockade of PD-1 and CTLA-4 have led to promising augmentation of effector immune responses in murine tumor models, and human antibodies against PD-1 and CTLA-4 alone or in combination have demonstrated tumor regression in clinical trials. The development of immune checkpoint blockade as a potential future immunotherapy has led to increasing interest in combining treatment modalities. Combination checkpoint blockade with chemotherapy and radiation therapy has shown synergistic effects in pre-clinical and clinical studies, and combination checkpoint blockade with bacterial vaccine vectors have produced increased effector immune responses in pre-clinical models. The future of immune checkpoint blockade may be as a powerful adjuvant alongside the current standard of care.

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.

The role of checkpoints in the treatment of GBM

Targeted immunotherapy is founded on the principle that augmentation of effector T cell activity in the tumor microenvironment can translate to tumor regression. Targeted checkpoint inhibitors in the form of agonist or antagonist monoclonal antibodies have come to the fore as a promising strategy to activate systemic immunity and enhance T cell activity by blocking negative signals, enhancing positive signals, or altering the cytokine milieu. This review will examine several immune checkpoints and checkpoint modulators that play a role in cancer pathogenesis, with an emphasis on malignant gliomas.

The ipilimumab lesson in melanoma: achieving long-term survival

The anti-cytotoxic T-lymphocyte antigen-4 (anti-CTLA-4) antibody ipilimumab is the first treatment that significantly improved the survival rates of metastatic melanoma patients, marking a new era in the treatment of melanoma. During its development, a hallmark of ipilimumab therapy was the extended duration of response, achieved in 20% of patients. The follow-up of patients included in phase II and phase III trials and in expanded access programs revealed that the survival rates remained stable after 3 years. These results demonstrated that ipilimumab induces an effective anti-tumor immune response persisting after the completion of treatment, and suggested a potential remission in a subset of patients. In this article we review the development of ipilimumab and highlight the long-term results. This approach emphasizes the need to optimize the use of ipilimumab in the future, by identifying the patients most likely to achieve long term survival after ipilimumab therapy, and by developing combined therapeutic approaches involving cytotoxic agents, targeted therapies or other immunotherapies to achieve durable control in a larger proportion of patients.

Combinatorial approach to treatment of melanoma

There are multiple effective and well-tolerated systemic therapy treatments for the treatment of advanced melanoma, as well as new immunotherapy and targeted therapy agents in clinical trials. Traditional cytotoxic chemotherapy and targeted BRAF inhibitors can increase antigen presentation and can rebalance the intratumoral immune milieu. The combination of pulsed cytotoxic therapy and immunotherapy is a logical next step in designing treatment regimens. Combination radiotherapy and immunotherapy also has experimental and clinical support. The standard of care for patients with advanced melanoma remains participation in clinical trials in order to enhance understanding of the effectiveness and toxicities of combination regimens.

[Systemic treatment of melanoma brain metastases]

Melanomas have a high rate of brain metastases. Both the functional prognosis and the overall survival are poor in these patients. Until now, surgery and radiotherapy represented the two main modalities of treatment. Nevertheless, due to the improvement in the management of the extracerebral melanoma, the systemic treatment may be an option in patients with brain metastases. Immunotherapy with anti-CTLA4 (cytotoxic T-lymphocyte-associated protein 4) - ipilimumab - or BRAF (serine/threonine-protein kinase B-raf) inhibitors - vemurafenib, dabrafenib - has shown efficacy in the management of brain metastases in a- or pauci-symptomatic patients. Studies are ongoing with anti-PD1 (programmed cell death 1) and combinations of targeted therapies associating anti-RAF (raf proto-oncogene, serine/threonine kinase) and anti-MEK (mitogen-activated protein kinase kinase).

Targeted and immunotherapeutic approaches in brain metastases

Brain metastases are a common and devastating complication of cancer. The approach to the management of brain metastases is often multidisciplinary and includes surgery, whole-brain radiation therapy (WBRT), stereotactic radiosurgery (SRS), and systemic therapeutic agents. Until recently, systemic therapy has had a limited role in the management of brain metastases because of a lack of activity, challenges of blood-brain barrier penetration, the heterogeneous patient population, and a heavily pretreated patient population. Advances in the understanding of the biology of brain metastases and molecularly defined disease subsets have facilitated an emerging role of novel therapeutic agents, including targeted therapies and immunotherapy, in the management of brain metastases.

The development of immunomodulatory monoclonal antibodies as a new therapeutic modality for cancer: the Bristol-Myers Squibb experience

The discovery and increased understanding of the complex interactions regulating the immune system have contributed to the pharmacologic activation of antitumor immunity. The activity of effector cells, such as T and NK cells, is regulated by an array of activating and attenuating receptors and ligands. Agents that target these molecules can modulate immune responses by exerting antagonistic or agonistic effects. Several T- or NK-cell modulators have entered clinical trials, and two have been approved for use. Ipilimumab (Yervoy®, Bristol-Myers Squibb) and nivolumab (OPDIVO, Ono Pharmaceutical Co., Ltd./Bristol-Myers Squibb) were approved for the treatment of metastatic melanoma, in March 2011 in the United States, and in July 2014 in Japan, respectively. The clinical activity of these two antibodies has not been limited to tumor types considered sensitive to immunotherapy, and promising activity has been reported in other solid and hematologic tumors. Clinical development of ipilimumab and nivolumab has presented unique challenges in terms of safety and efficacy, requiring the establishment of new evaluation criteria for adverse events and antitumor effects. Guidelines intended to help oncologists properly manage treatment in view of these non-traditional features have been implemented. The introduction of this new modality of cancer treatment, which is meant to integrate with or replace the current standards of care, requires additional efforts in terms of optimization of treatment administration, identification of biomarkers and application of new clinical trial designs. The availability of immune modulators with different mechanisms of action offers the opportunity to establish immunological combinations as new standards of care.

The role of chemotherapy in the modern management of melanoma

The last 4 years have seen dramatic changes in the treatment of advanced melanoma, largely based on advances in targeted therapy and immunotherapy. This article examines the role of chemotherapy in the modern management of melanoma. We examine the evidence for promising new agents and discuss their position in the sequencing of treatment options for patients with advanced disease. In addition, we discuss the combination of chemotherapy with targeted treatments and immune therapies. Finally, we discuss future areas of research for ensuring that we maximize the potential of all agents available to us and identify new, effective treatments.

Ipilimumab in the treatment of advanced melanoma - a clinical update

INTRODUCTION

Ipilimumab has become an important treatment option for patients with advanced melanoma; however, active research perseveres to resolve many clinical practice issues and to further improve the therapeutic index of this agent.

AREAS COVERED

This article aims to provide an update on long-term data, current challenge and recent progress relating to the clinical application of ipilimumab in the treatment of advanced melanoma. A literature search using PubMed database was conducted using search words ipilimumab, melanoma, treatment sequencing, adjuvant therapy, combination therapy, and biomarkers. Data were also obtained from meeting abstracts and clinical trial registries.

EXPERT OPINION

Signal of clinical activity as adjuvant therapy in patients with resected high-risk melanoma begins to emerge, but longer follow-up is required for confirmation. Many issues, such as optimal dosing schedules and therapeutic sequences, remain unraveled. At present, treatment should be individualized based on patient- and disease-specific factors. Immunotherapy like ipilimumab still represents the best treatment option for durable remission; however, targeted therapies are more appropriate for patients with BRAF V600-mutated tumor who are symptomatic or have rapidly growing disease. With novel therapeutic options in the pipeline, the role of ipilimumab continues to evolve in the rapidly changing treatment landscape of advanced melanoma. Most likely, this agent will be utilized in combinatorial or sequential approach.

Emerging immunotherapy strategies in breast cancer

Although immunogenicity is typically associated with renal cell carcinomas and melanoma, there are several compelling reasons why immune-based therapies should be explored in breast cancer. First, breast cancers express multiple putative tumor-associated antigens, such as HER-2 and MUC-1, which have been the successful focus of vaccine development over the past decade, translating into tumor-specific immune responses and, in some cases, clinical benefit. Second, passive immune strategies with anti-HER-2 antibodies, such as trastuzumab and pertuzumab, have led to survival benefits in breast cancer. Finally, the successes observed with novel immunotherapeutic strategies, such as immune checkpoint blockade and adoptive T-cell therapies in other malignancies, combined with a growing body of literature that supports an interplay between solid tumors and the immune system, indicate that these strategies have the potential to revolutionize the treatment of breast cancer.

Translesion polymerase η is upregulated by cancer therapeutics and confers anticancer drug resistance

DNA repair processes are a key determinant of the sensitivity of cancer cells to DNA-damaging chemotherapeutics, which may induce certain repair genes as a mechanism to promote resistance. Here, we report the results of a screen for repair genes induced in cancer cells treated with DNA crosslinking agents, which identified the translesion polymerase η (PolH) as a p53-regulated target acting as one defense against interstrand crosslink (ICL)-inducing agents. PolH was induced by fotemustine, mafosfamide, and lomustine in breast cancer, glioma, and melanoma cells in vitro and in vivo, with similar inductions observed in normal cells such as lymphocytes and diploid fibroblasts. PolH contributions to the protection against ICL-inducing agents were evaluated by its siRNA-mediated attenuation in cells, which elevated sensitivity to these drugs in all tumor cell models. Conversely, PolH overexpression protected cancer cells against these drugs. PolH attenuation reduced repair of ICL lesions as measured by host cell reactivation assays and enhanced persistence of γH2AX foci. Moreover, we observed a strong accumulation of PolH in the nucleus of drug-treated cells along with direct binding to damaged DNA. Taken together, our findings implicated PolH in ICL repair as a mechanism of cancer drug resistance and normal tissue protection.

Combination therapies in advanced melanoma

Until recently, melanoma represented a significant clinical challenge to oncologists. However, the approval in 2011 of ipilimumab, an anti-CTLA4 monoclonal antibody, and vemurafenib, a BRAF inhibitor, completely changed melanoma management, with both drugs being shown to improve overall survival. The advent of these two drugs, together with the ongoing development of other targeted agents (e.g., MEK inhibitors) and immunotherapeutic compounds (e.g., anti-PD-L1), is providing the opportunity to trial new combination or sequential therapy approaches. Combined approaches of these new agents with surgery, radiotherapy and/or chemotherapy are also being assessed. Targeted agents in combination or in sequence with new immunotherapeutic compounds may represent the future, not only for the treatment of melanoma, but also for the treatment of cancer in general.

Durable benefit and the potential for long-term survival with immunotherapy in advanced melanoma

Historically, the median overall survival for patients with stage IV melanoma was less than 1 year and the 5-year survival rate was ∼10%. Recent advances in therapy have raised 5-year survival expectations to ∼20%. Notably, a subset of melanoma patients who receive immunotherapy with high-dose interleukin-2, and now ipilimumab, can achieve long-term survival of at least 5 years. A major goal in melanoma research is to increase the number of patients who experience this overall survival benefit. In this review, we discuss the attributes of immunotherapy and newer targeted agents, and consider how combination strategies might improve the chances of achieving durable benefit and long-term survival. We also discuss three areas that we believe will be critical to making further advances in melanoma treatment. To better understand the clinical profile of patients who achieve long-term survival with immunotherapy, we first present data from ipilimumab clinical trials in which a subset of patients experienced durable responses. Second, we discuss the limitations of traditional metrics used to evaluate the benefits of immunotherapies. Third, we consider emerging issues that clinicians are currently facing when making treatment decisions regarding immunotherapy. A better understanding of these novel treatments may improve survival outcomes in melanoma, increase the number of patients who experience this overall survival benefit, and inform the future use of these agents in the treatment of other cancer types.

Cancer, inflammation, and therapy: effects on cytochrome p450-mediated drug metabolism and implications for novel immunotherapeutic agents

Immune system activation through innate and adaptive systemic mechanisms is critical for protection from pathogens and other antigens. However, uncontrolled systemic inflammation may occur as a consequence of acute and chronic conditions and has multiple clinically relevant effects. Inflammation and cancer are fundamentally linked during development, invasion, and metastasis, yet, paradoxically, many cancers evade immune system detection. Components of cancer inflammation include chemokines, prostaglandins, and cytokines, and these have been shown to downregulate cytochrome P450 (CYP) enzyme activity. Recently, promising novel anticancer agents that upregulate immune responses have entered into clinical practice and have shown high response rates. These agents, either alone or in combinations, may cause systemic immune-related adverse events, with potential clinical implications for use of concurrent agents metabolized by CYP and other pathways. In this article, the authors focus on what is known about inflammation, cancer, and CYP-mediated drug metabolism; discuss clinical and pharmacologic data regarding novel immunomodulators; and consider their potential interactions with concurrent agents.

Brain metastasis: new opportunities to tackle therapeutic resistance

Brain metastasis is a devastating complication of cancer with unmet therapeutic needs. The incidence of brain metastasis has been rising in cancer patients and its response to treatment is limited due to the singular characteristics of brain metastasis (i.e., blood-brain-barrier, immune system, stroma). Despite improvements in the treatment and control of extracranial disease, the outcomes of patients with brain metastasis remain dismal. The mechanisms that allow tumor cells to promulgate metastases to the brain remain poorly understood. Further work is required to identify the molecular alterations inherent to brain metastasis in order to identify novel therapeutic targets and explicate the mechanisms of resistance to systemic therapeutics. In this article, we review current knowledge of the unique characteristics of brain metastasis, implications in therapeutic resistance, and the possibility of developing biomarkers to rationally guide the use of targeted agents.

What have we learned from cancer immunotherapy in the last 3 years?

Until recently, most immunotherapeutic approaches used to fight cancer were ineffective, counteracted by the tumour's ability to evade immune attack. However, extensive research has improved our understanding of tumour immunology and enabled the development of novel treatments that can harness the patient's immune system and prevent immune escape. Over the last few years, through numerous clinical trials and real-world experience, we have accumulated a large amount of evidence regarding the potential for long-term survival with immunotherapy agents in various types of malignancy. The results of these studies have also highlighted a number of recurring observations with immuno-oncology agents, including their potential for clinical application across a broad patient population and for both conventional and unconventional response patterns. Furthermore, given the numerous immune checkpoints that exist and the multiple mechanisms used by tumours to escape the immune system, targeting distinct checkpoint pathways using combination approaches is an attractive therapeutic strategy with the potential to further enhance the antitumour immune response.

Efficacy and safety of ipilimumab in patients with advanced melanoma and brain metastases

Patients with melanoma brain metastases have a poor prognosis and historically have been excluded from clinical trials. The Expanded Access Program (EAP) provided an opportunity to evaluate the feasibility of ipilimumab (3 mg/kg every 3 weeks for four doses) in patients with stage 3 (unresectable) or 4 melanoma and asymptomatic brain metastases, who had failed or did not tolerate previous treatments and had no other therapeutic option available. Tumor assessments were conducted at baseline and week 12 using immune-related response criteria and patients were monitored for adverse events (AEs). Of 855 patients participating in the EAP in Italy, 146 had asymptomatic brain metastases. With a median follow-up of 4 months, the global disease control rate was 27%, including 4 patients with a complete response and 13 with a partial response. Median progression-free survival and overall survival were 2.8 and 4.3 months, respectively and approximately one-fifth of patients were alive 1 year after starting ipilimumab. In total, 29% of patients reported a treatment-related AE of any grade, which were grade 3/4 in 6% of patients. AEs were generally reversible with treatment as per protocol-specific guidelines. Ipilimumab shows durable benefits in some patients with advanced melanoma metastatic to the brain, with safety results consistent with those previously reported in clinical trials.

The role of O6-methylguanine-DNA methyltransferase in a long-surviving metastatic melanoma

BACKGROUND

Brain metastases commonly occur in patients with metastatic melanoma and are associated with a poor prognosis. Only a few chemotherapeutic agents have been shown to be potentially active. Resistance to chemotherapy is one of the main limitations to treatment. A key mechanism of resistance is O6-methylguanine-DNA methyltransferase (MGMT). The methylation of its promotor could inhibit the activity of this enzyme; consequently, it is very important to evaluate the methylation status of all available specimens.

CASE REPORT

We report the case of a long-surviving patient in whom combination treatment with an alkylating agent inhibiting MGMT, such as temozolomide, was useful in clinical control of the disease.

Melanoma brain metastases: an unmet challenge in the era of active therapy

Metastatic disease to the brain is a frequent manifestation of melanoma and is associated with significant morbidity and mortality and poor prognosis. Surgery and stereotactic radiosurgery provide local control but less frequently affect the overall outcome of melanoma brain metastases (MBM). The role of systemic therapies for active brain lesions has been largely underinvestigated, and patients with active brain lesions are excluded from the vast majority of clinical trials. The advent of active systemic therapy has revolutionized the care of melanoma patients, but this benefit has not been systematically translated into intracranial activity. In this article, we review the biology and clinical outcomes of patients with MBM, and the evidence supporting the use of radiation, surgery, and systemic therapy in MBM. Prospective studies that included patients with active MBM have shown clinical intracranial activity that parallels systemic activity and support the inclusion of patients with active MBM in clinical trials involving novel agents and combination therapies.

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.

Emerging options for the treatment of melanoma - focus on ipilimumab

Ipilimumab is a fully human immunoglobulin subclass G1 anticytotoxic-T-lymphocyte-antigen-4 monoclonal antibody. It has been approved by the US Food and Drug Administration (FDA) and the European Medicines Agency for use in advanced melanoma following clear evidence of survival benefit in randomized Phase III studies. It is also under investigation as a treatment for other solid tumors such as renal cell, lung, and prostate cancers. The purported mechanism of antitumor activity of ipilimumab is through T-cell activation, and the side effect profile reflects this. Immune-related adverse events (irAEs) affect 60% of treated patients and 15% are defined as severe. Fortunately, most irAEs are reversible with early diagnosis and correct management. FDA approval of ipilimumab is dependent on the careful execution of a risk evaluation and mitigation strategy, with the aim of increasing awareness amongst patients and clinicians of the immunological risks of treatment, and providing algorithms for management of irAEs as they develop. Ipilimumab is one of the first immunotherapies to become widely available in the setting of solid tumors, and ongoing research aims to elucidate optimal dosing, optimal scheduling, and expanded access to ipilimumab as an adjuvant or maintenance therapy where appropriate. The identification of clinical correlates or biomarkers to identify those likely to benefit from this high-cost therapy is a top priority.

Marker utility for combination therapy

Melanoma is a heterogeneous disease for which monotherapies are likely to fail in the majority of patients due to genomic variations between individuals. Novel treatments, such as vemurafenib and ipilimumab, offer clinical promise in metastatic melanoma and the increased potential for combined therapeutic strategies, necessary given the differences in response between patients. Together with these new approaches, the development of clinically relevant biomarkers that predict treatment outcomes are required to ensure these new therapies are targeted at those patients most likely to benefit. Here we review the utility of some potential biomarkers of treatment response in patients with metastatic melanoma.

[What’s new in dermato-oncology?]

During this year 2013, Onco-dermatology was the object of numerous publications, especially in the field of metastatic melanoma. Previous results concerning anti PD-1 have been consolidated. Studies concerning Mek inhibitors have been published with promising results in uveal melanoma. In metastatic melanoma two combinations showed great results: combination of ipilimumab and nivolumab and combination of B-RAF and MEK inhibitors. Some studies demonstrated efficacy of these new therapeutics (ipilimumab, vemurafenib and dabrafenib) in brain metastasis. Moreover, the year 2013 was marked by the increasing knowledge in the management of adverse events induced by these new treatments. In the field of basal cell carcinoma, after the publication of large scale studies, vismodegib, the inhibitor of the hedgehog signalling pathway, was approved by the European Medicines Agency.

Targeting brain metastases in patients with melanoma

Patients with brain metastases from malignant melanoma historically have a very poor outcome. Surgery and radiotherapy can be used, but for the majority of patients the disease will progress quickly. In the recent past, patients with brain metastases derived only minimal benefit from cytotoxic chemotherapy. Novel therapies that have been shown to be superior to chemotherapy in metastatic melanoma have made their way in clinic and data regarding their use in patients with treated or untreated brain metastases are encouraging. In this paper we describe the use of vemurafenib, dabrafenib, and ipilimumab in patients with melanoma disseminated to the brain in addition to other treatments currently in development.

Endocrine side-effects of anti-cancer drugs: mAbs and pituitary dysfunction: clinical evidence and pathogenic hypotheses

mAbs are established targeted therapies for several diseases, including hematological and solid malignancies. These agents have shown a favorable toxicity profile, but, despite their high selectivity, new typical side-effects have emerged. In cancer patients, pituitary dysfunction may be mainly due to brain metastases or primary tumors and to related surgery and radiotherapy. Anticancer agents may induce hypopituitarism in patients cured for childhood cancers. These agents infrequently affect pituitary function in adult cancer patients. Notably, hypophysitis, a previously very rare disease, has emerged as a distinctive side-effect of ipilimumab and tremelimumab, two mAbs inhibiting the cytotoxic T-lymphocyte antigen-4 receptor, being occasionally seen with nivolumab, another immune checkpoint inhibitor. Enhanced antitumor immunity is the suggested mechanism of action of these drugs and autoimmunity the presumptive mechanism of their toxicity. Recently, ipilimumab has been licensed for the treatment of patients affected by metastatic melanoma. With the expanding use of these drugs, hypophysitis will be progressively encountered by oncologists and endocrinologists in clinical practice. The optimal management of this potentially life-threatening adverse event needs a rapid and timely diagnostic and therapeutic intervention. Hypopituitarism caused by these agents is rarely reversible, requiring prolonged or lifelong substitutive hormonal treatment. Further studies are needed to clarify several clinical and pathogenic aspects of this new form of secondary pituitary dysfunction.

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.

Revisiting the role of systemic therapies in patients with metastatic melanoma to the CNS

The CNS is a common site of metastasis in patients with malignant melanoma. Locoregional control either with surgery or radiotherapy is first-line treatment for patients with brain metastasis should they be suitable candidates. For those patients who are not and those who progress after previous treatment, there is an unmet clinical need for effective systemic therapies. Systemic cytotoxics, such as temozolamide and fotemustine, have only modest activity, resulting in a median progression-free survival ranging from 1-2 months, in patients with metastatic melanoma to the brain. Newer systemic treatments such as vemurafenib and ipilimumab have been approved for the treatment of melanoma, but evidence regarding their activity in brain metastases is inconclusive due to the limited access of patients to clinical trials. This is now being revised and more data are emerging supporting the inclusion of patients with brain metastasis in trials. In this review, the authors present data regarding the efficacy of systemically administered therapies in patients with metastatic melanoma to the brain.