Combined Nivolumab and Ipilimumab or Monotherapy in Untreated Melanoma

The Efficacy and Safety of Programmed Cell Death 1 and Programmed Cell Death 1 Ligand Inhibitors for Advanced Melanoma: A Meta-Analysis of Clinical Trials Following the PRISMA Guidelines

The purpose of this study was to investigate the efficacy and safety of programmed cell death 1 (PD-1) and programmed cell death 1 ligand (PD-L1) inhibitors using a meta-analysis of present trials for advanced melanoma. A fully recursive literature search of the primary electronic databases for available trials was performed. The objective response rate (ORR) and the median progression-free survival (PFS) of clinical responses were considered the main endpoints to evaluate the efficacy, whereas Grade 3-4 adverse effects (AEs) were analyzed to evaluate safety. The ORR of PD-1 and PD-L1 inhibitors was 30% (95% CI: 25-35%). No significant difference in the ORR was observed after the comparisons of low-dose, median-dose, and high-dose cohorts. In addition, the rate of Grade 3-4 AEs was 9% (95% CI: 6-12%). According to the 3 randomized controlled trials that compared PD-1 inhibitors with chemotherapy, the difference between these 2 groups was found to be statistically significant with respect to the ORR, PFS and the incidence of Grade 3-4 AEs; that is, the relative risk (RR) of the ORR was 3.42 (95% CI: 2.49-4.69, P < 0.001), the hazard ratio (HR) of the PFS was 0.50 (95% CI: 0.44-0.58, P < 0.001), and the RR of Grade 3-4 AEs was 0.45 (95% CI: 0.31-0.65, P < 0.001). According to a meta-analysis of limited concurrent studies, PD-1 and PD-L1 inhibitors appear to be associated with improved response rates, superior response durability and tolerable toxicity in patients with advanced melanoma.

Opportunities and challenges in combination gene cancer therapy

Treatment for solid tumor malignancies, which constitute the majority of human cancers, is still dominated by surgery and radiotherapies. This is especially true for many localized solid tumors, which are often curable with these treatments. However, metastatic cancers are beyond the reach of these therapies, and many localized cancers that are initially treated with surgery and radiation will recur and metastasize. Thus, for over 60years there has been a concerted effort to develop effective drug treatments for metastatic cancers. Combination therapies are an increasingly important part of the anti-cancer drug armamentarium. In the case of cytotoxic chemotherapy, multi-drug regimens rapidly became the norm, as the earliest single agents were relatively ineffective. In contrast to chemotherapy, where combination therapies were required in order to achieve treatment efficacy, for both hormonal and targeted therapies the impetus to move toward the use of combination therapies is to prevent or reverse the development of treatment resistance. In addition, emerging evidence suggests that combination therapy may also improve cancer treatment by neutralizing an emerging treatment side effect termed therapy-induced metastasis, which accompanies some effective single agent therapies. Finally, although gene therapy is still far from use in the clinic, we propose that combination therapies may enhance its effectiveness.

Immune Checkpoint Therapy and the Search for Predictive Biomarkers

Immune checkpoint therapy has started a revolution in the field of oncology. The concept that the immune system plays a critical role in antitumor responses, which has been around for decades, has finally been proven and firmly established with elegant preclinical studies and dramatic clinical responses in patients as a result of antibodies that block inhibitory T-cell pathways. However, the clinical responses being achieved are only in a subset of patients, and more work is needed to provide a better understanding of the mechanisms that elicit tumor rejection, which will enable identification of appropriate biomarkers, reveal new targets, provide data to guide combination studies, and eventually dictate a platform that allows more patients to derive clinical benefit, including cures, with immune checkpoint therapy.

NRAS mutant melanoma: an overview for the clinician for melanoma management

Melanoma is the deadliest form of skin cancer and the incidence continues to rise in the United States and worldwide. Activating mutations in RAS oncogenes are found in roughly a third of all human cancers. Mutations in NRAS occur in approximately a fifth of cutaneous melanomas and are associated with aggressive clinical behavior. Cells harboring oncogenic NRAS mutations exhibit activation of multiple signaling cascades, including PI3K/Akt, MEK-ERK and RAL, which collectively stimulate cancer growth. While strategies to target N-Ras itself have proven ineffective, targeting one or more N-Ras effector pathways has shown promise in preclinical models. Despite promising preclinical data, current therapies for NRAS mutant melanoma remain limited. Immune checkpoint inhibitors and targeted therapies for BRAF mutant melanoma are transforming the treatment of metastatic melanoma, but the ideal treatment for NRAS mutant melanoma remains unknown. Improved understanding of NRAS mutant melanoma and relevant N-Ras effector signaling modules will be essential to develop new treatment strategies.

Novel targets in the treatment of advanced gastric cancer: a perspective review

Gastric cancer is responsible for a high burden of disease globally. Although more extensive use of chemotherapy together with the recent introduction of the two targeted agents trastuzumab and ramucirumab have contributed to marginal outcome prolongation, overall survival for patients with advanced stage disease remains poor. Over the last decade, a number of novel agents have been examined in clinical trials with largely disappointing results. Potential explanations for this are the absence of molecularly selected trial populations or weak predictive biomarkers within the context of a highly heterogeneous disease. In the recently published gastric cancer The Cancer Genome Atlas (TCGA) project a new classification of four different tumour subtypes according to different molecular characteristics has been proposed. With some overlap, several relatively distinct and potentially targetable pathways have been identified for each subtype. In this perspective review we match recent trial results with the subtypes described in the gastric cancer TCGA aiming to highlight data regarding novel agents under evaluation and to discuss whether this publication might provide a framework for future drug development.

PD-1 Pathway Inhibitors: Immuno-Oncology Agents for Restoring Antitumor Immune Responses

Immune checkpoint inhibitors are designed to restore a patient's own antitumor immune response that has been suppressed during tumor development. The first monoclonal antibodies against the immune checkpoint programmed death 1 (PD-1) receptor, nivolumab and pembrolizumab, are now approved for clinical use. Both agents are indicated for the treatment of advanced melanoma, as well as for the treatment of metastatic non-small cell lung cancer (NSCLC). Nivolumab is also approved for the treatment of advanced renal cell carcinoma. In patients with melanoma, these agents result in objective response rates of ~25-40%, with durable responses lasting more than 2 years in some cases. Results from phase III trials have shown improved survival with nivolumab versus standard-of-care chemotherapy in both patients with advanced melanoma and those with advanced NSCLC. In patients with advanced melanoma, both PD-1 inhibitors (nivolumab and pembrolizumab) have shown improved survival versus ipilimumab. PD-1 inhibitors are associated with adverse events that have immune etiologies, with grade greater than 3 adverse events typically reported in 16% or less of patients. However, most immune-mediated adverse events (including grade 3-4 adverse events) can be managed by using published management algorithms without permanent discontinuation of the agent. As nivolumab and pembrolizumab enter the clinic, and with more PD-1 pathway agents in development for a range of tumor types, this review aims to provide pharmacists with a basic understanding of the role of PD-1 in modulating the immune system and their use in the cancer treatment. The most recent clinical efficacy and safety data are discussed, highlighting the response characteristics distinctive to immune checkpoint inhibitors, along with pharmacokinetic and pharmacodynamic data and cost considerations.

Clinical utility of nivolumab in the treatment of advanced melanoma

Melanomas are highly immunogenic tumors that evade the immune system by exploiting innate checkpoint pathways, rendering effector T-cells anergic. The immunotherapeutic approach of checkpoint inhibition can restore and invigorate endogenous antitumor T-cell responses and has become an important treatment option for patients with advanced melanoma. The CTLA-4 inhibitor ipilimumab and the PD-1 inhibitors nivolumab and pembrolizumab have been shown to induce durable responses and improve overall survival in metastatic, refractory melanoma. Optimization and validation of pretreatment biomarkers to predict response to these agents is a crucial area of ongoing research. Combination immunotherapy has recently demonstrated superior response rates compared to monotherapy; further investigation is needed to refine combinatorial strategies.

Targeting metabolic reprogramming as a potential therapeutic strategy in melanoma

Metabolic reprogramming is a recognized hallmark of cancer. In order to support continued proliferation and growth, tumor cells must metabolically adapt to balance their bioenergetic and biosynthetic needs. To achieve this, cancer cells switch from mitochondrial oxidative phosphorylation to predominantly rely on glycolysis, a process known as the "Warburg effect". The BRAF oncogene has recently emerged as a critical regulator of this process in melanoma, bringing to the fore the importance of metabolic reprogramming in the pathogenesis and treatment of metastatic melanoma. In this review, we summarize our current understanding of oncogenic reprogramming of metabolism in BRAF and NRAS mutant melanoma, and highlight emerging evidence supporting a metabolic basis for MAPK pathway inhibitor resistance and metabolic vulnerabilities that may be exploited to overcome this.

The proportion cured of patients diagnosed with Stage III-IV cutaneous malignant melanoma in Sweden 1990-2007: A population-based study

The survival in cutaneous malignant melanoma (CMM) is highly dependent on the stage of the disease. Stage III-IV CMM patients are at high risk of relapse with a heterogeneous outcome, but not all experience excess mortality due to their disease. This group is referred to as the cure proportion representing the proportion of patients who experience the same mortality rate as the general population. The aim of this study was to estimate the cure proportion of patients diagnosed with Stage III-IV CMM in Sweden. From the population-based Swedish Melanoma Register, we included 856 patients diagnosed with primary Stage III-IV CMM, 1990-2007, followed-up through 2013. We used flexible parametric cure models to estimate cure proportions and median survival times (MSTs) of uncured by sex, age, tumor site, ulceration status (in Stage III patients) and disease stage. The standardized (over sex, age and site) cure proportion was lower in Stage IV CMMs (0.15, 95% CI 0.09-0.22) than non-ulcerated Stage III CMMs (0.48, 95% CI 0.41-0.55) with a statistically significant difference of 0.33 (95% CI = 0.24-0.41). Ulcerated Stage III CMMs had a cure proportion of 0.27 (95% CI 0.21-0.32) with a statistically significant difference compared to non-ulcerated Stage III CMMs (difference 0.21; 95% CI = 0.13-0.30). The standardized MST of uncured was approximately 9-10 months longer for non-ulcerated versus ulcerated Stage III CMMs. We could demonstrate a significantly better outcome in patients diagnosed with non-ulcerated Stage III CMMs compared to ulcerated Stage III CMMs and Stage IV disease after adjusting for age, sex and tumor site.

Coinhibitory Pathways in Immunotherapy for Cancer

The immune system is capable of recognizing tumors and eliminates many early malignant cells. However, tumors evolve to evade immune attack, and the tumor microenvironment is immunosuppressive. Immune responses are regulated by a number of immunological checkpoints that promote protective immunity and maintain tolerance. T cell coinhibitory pathways restrict the strength and duration of immune responses, thereby limiting immune-mediated tissue damage, controlling resolution of inflammation, and maintaining tolerance to prevent autoimmunity. Tumors exploit these coinhibitory pathways to evade immune eradication. Blockade of the PD-1 and CTLA-4 checkpoints is proving to be an effective and durable cancer immunotherapy in a subset of patients with a variety of tumor types, and additional combinations are further improving response rates. In this review we discuss the immunoregulatory functions of coinhibitory pathways and their translation to effective immunotherapies for cancer.

Enhancing the safety of antibody-based immunomodulatory cancer therapy without compromising therapeutic benefit: Can we have our cake and eat it too?

INTRODUCTION

Monoclonal antibodies (mAbs) targeting checkpoint inhibitors have demonstrated clinical benefit in treating patients with cancer and have paved the way for additional immune-modulating mAbs such as those targeting costimulatory receptors. The full clinical utility of these agents, however, is hampered by immune-related adverse events (irAEs) that can occur during therapy.

AREAS COVERED

We first provide a general overview of tumor immunity, followed by a review of the two major classes of immunomodulatory mAbs being developed as cancer therapeutics: checkpoint inhibitors and costimulatory receptor agonists. We then discuss therapy-associated adverse events. Finally, we describe in detail the mechanisms driving their therapeutic activity, with an emphasis on interactions between antibody fragment crystallizable (Fc) domains and Fc receptors (FcR).

EXPERT OPINION

Given that Fc-FcR interactions appear critical in facilitating the ability of immunomodulatory mAbs to elicit both therapeutically useful as well as adverse effects, the engineering of mAbs that can effectively engage their targets while limiting interaction with FcRs might represent a promising future avenue for developing the next generation of immune-enhancing tumoricidal agents with increased safety and retention of efficacy.

High immunosuppressive burden in cancer patients: a major hurdle for cancer immunotherapy

A bottleneck for immunotherapy of cancer is the immunosuppressive microenvironment in which the tumor cells are located. Regardless of the fact that large numbers of tumor-specific T cells can be generated in patients by active immunization or adoptive transfer, these T cells do not readily translate to tumor cell killing in vivo. The immune regulatory mechanism that prevents autoimmunity may be harnessed by tumor cells for the evasion of immune destruction. Regulatory T cells, myeloid-derived suppressor cells, inhibitory cytokines and immune checkpoint receptors are the major components of the immune system acting in concert with causing the subversion of anti-tumor immunity in the tumor microenvironment. This redundant immunosuppressive network may pose an impediment to efficacious immunotherapy, thus facilitating tumor progression. Cancer progression clearly documents the failure of immune control over relentless growth of tumor cells. Detailed knowledge of each of these factors responsible for creating an immunosuppressive shield to protect tumor cells from immune destruction is essential for the development of novel immune-based therapeutic interventions of cancer. Multipronged targeted depletion of these suppressor cells may restore production of granzyme B by CD8(+) T cells and increase the number of IFN-γ-producing CD4(+) T cells.

Immune checkpoint blockade in lymphoid malignancies

Malignant cells may subvert and escape endogenous host immune surveillance by up-regulation of immune inhibitory signals known as immune checkpoints. These checkpoints are important therapeutic targets, and antibodies that block checkpoint signaling have shown remarkable efficacy in some solid tumors as well as in some refractory hematologic malignancies. In hematologic cancers, the mechanism of these checkpoints is complex, as the tumor and immune system are one and the same. In this review, we evaluate the biology of checkpoint inhibition, review the current data on its efficacy in lymphoid tumors, and explore uncertainties in the field, including those involving the precise mechanisms of action, the appropriate timing of therapy, and the differences in response rate between lymphoid tumor types.

PD-1/PD-L1 blockade in cancer treatment: perspectives and issues

Recent studies showed that tumor cells ‘edit’ host immunity in several ways to evade immune defenses in the tumor microenvironment. This phenomenon is called “cancer immune escape.” One of the most important components in this system is an immunosuppressive co-signal (immune checkpoint) mediated by the PD-1 receptor and its ligand, PD-L1. PD-1 is mainly expressed on activated T cells, whereas PD-L1 is expressed on several types of tumor cells. Preclinical studies have shown that inhibition of the interaction between PD-1 and PD-L1 enhances the T-cell response and mediates antitumor activity. Several clinical trials of PD-1/PD-L1 signal-blockade agents have exhibited dramatic antitumor efficacy in patients with certain types of solid or hematological malignancies. In this review, we highlight recent clinical trials using anti-PD-1 or anti-PD-L1 antibodies against several types of malignancies, including a trial conducted in our department, and describe the clinical perspectives and issues regarding the PD-1/PD-L1 blockade in cancer treatment.

Anti-TNF-refractory colitis after checkpoint inhibitor therapy: Possible role of CMV-mediated immunopathogenesis

Immune-related adverse events (irAEs) induced by checkpoint inhibitors are well known. Since fatal outcomes have been reported early detection and adequate management are crucial. In particular, colitis is frequently observed and can result in intestinal perforation. This is the first report of an autoimmune colitis that was treated according to algorithms but became resistant due to a CMV reactivation. The 32-y-old male patient with metastatic melanoma treated within an anti-PD-1/ipilimumab combination study developed severe immune-mediated colitis (CTCAE grade 3) with up to 18 watery stools per day starting 2 weeks after treatment initiation. After improving upon therapy with immunosuppressive treatment (high dose steroids and infliximab) combined with parenteral nutrition diarrhea again exacerbated. Additionally, the patient had asymptomatic grade 3 CTCAE amylase and lipase elevation. Colitis was monitored by weekly endoscopies and colon biopsies were analyzed histologically with CMV staining, multi-epitope ligand cartography (MELC) and qRT-PCR for inflammatory genes. In the course, CMV reactivation was detected in the colon and treated with antiviral medication in parallel to a reduction of corticosteroids. Subsequently, symptoms improved. The patient showed a complete response for 2 y now including regression of bone metastases. CMV reactivation under checkpoint inhibitor therapy in combination with immunosuppressive treatment for autoimmune side effects has to be considered in these patients and if present treated. Potentially, CMV reactivation is underdiagnosed. Treatment algorithms should include CMV diagnostics.

Ipilimumab reshapes T cell memory subsets in melanoma patients with clinical response

PURPOSE

Therapy targeting CTLA-4 immune checkpoint provides increased survival in patients with advanced melanoma. However, immunotherapy is frequently associated with delayed and heterogeneous clinical responses and it is important to identify prognostic immunological correlates of clinical endpoints.

EXPERIMENTAL DESIGN

77 patients with stage III/IV melanoma were treated with ipilimumab alone every 3 weeks, during 9 weeks. Blood samples were collected at the baseline and before each dose for in depth immune monitoring.

RESULTS

The median follow-up was 28 mo with a median survival of 7 mo. Survival and clinical benefit were significantly improved when absolute lymphocyte count at the baseline was above 1 × 10(9)/L. Notably, ipilimumab had a global effect on memory T cells, with an early increase of central and effector subsets in patients with disease control. By contrast, percentages of stem cell memory T cells (TSCM) gradually decreased despite stable absolute counts and sustained proliferation, suggesting a process of differentiation. Higher proportions of eomes(+) and Ki-67(+) T cells were observed, with enhanced skin homing potential and induction of cytotoxic markers.

CONCLUSION

These results suggest that CTLA-4 blockade is able to reshape the memory subset with the potential involvement of Eomes and memory subsets including TSCM.

Prioritization schema for immunotherapy clinical trials in glioblastoma

BACKGROUND

Emerging immunotherapeutic strategies for the treatment of glioblastoma (GBM) such as dendritic cell (DC) vaccines, heat shock proteins, peptide vaccines, and adoptive T-cell therapeutics, to name a few, have transitioned from the bench to clinical trials. With upcoming strategies and developing therapeutics, it is challenging to critically evaluate the practical, clinical potential of individual approaches and to advise patients on the most promising clinical trials.

METHODS

The authors propose a system to prioritize such therapies in an organized and data-driven fashion. This schema is based on four categories of factors: antigenic target robustness, immune-activation and -effector responses, preclinical vetting, and early evidence of clinical response. Each of these categories is subdivided to focus on the most salient elements for developing a successful immunotherapeutic approach for GBM, and a numerical score is generated.

RESULTS

The Score Card reveals therapeutics that have the most robust data to support their use, provides a reference prioritization score, and can be applied in a reiterative fashion with emerging data.

CONCLUSIONS

The authors hope that this schema will give physicians an evidence-based and rational framework to make the best referral decisions to better guide and serve this patient population.

Skin tumor immunity: Site does matter for antigen presentation by DCs

The immune system has the ability to specifically identify and eliminate tumors, but the underlying mechanisms responsible for this phenomenon are not fully understood. A study published in this issue of the European Journal of Immunology now provides new insights into this important problem. Joncker et al. [Eur. J. Immunol. 2016. 46: 609-618] show that the timely mobilization of tumor antigen-bearing dendritic cells (DCs) from the periphery to the lymph nodes is critical for effective antitumor T-cell immunity, and that DCs present tumor antigens much more efficiently when encountered in the skin rather than in the subcutaneous tissues.

Low temperature plasmas as emerging cancer therapeutics: the state of play and thoughts for the future

The field of plasma medicine has seen substantial advances over the last decade, with applications developed for bacterial sterilisation, wound healing and cancer treatment. Low temperature plasmas (LTPs) are particularly suited for medical purposes since they are operated in the laboratory at atmospheric pressure and room temperature, providing a rich source of reactive oxygen and nitrogen species (RONS). A great deal of research has been conducted into the role of reactive species in both the growth and treatment of cancer, where long-established radio- and chemo-therapies exploit their ability to induce potent cytopathic effects. In addition to producing a plethora of RONS, LTPs can also create strong electroporative fields. From an application perspective, it has been shown that LTPs can be applied precisely to a small target area. On this basis, LTPs have been proposed as a promising future strategy to accurately and effectively control and eradicate tumours. This review aims to evaluate the current state of the literature in the field of plasma oncology and highlight the potential for the use of LTPs in combination therapy. We also present novel data on the effect of LTPs on cancer stem cells, and speculatively outline how LTPs could circumvent treatment resistance encountered with existing therapeutics.

Diagnosis, monitoring and management of immune-related adverse drug reactions of anti-PD-1 antibody therapy

PD-1 checkpoint inhibitors are associated with a specific spectrum of immune-related adverse events. This spectrum is different from toxicities known for kinase inhibitors or cytotoxic drugs. Since PD-1 directed therapies show effectivity in an increasing number of malignant diseases, their clinical usage will increase rapidly. Therefore clinicians from different specialities such as medical oncology, internal medicine, family doctors and emergency unit staff should be aware of the adverse effects of PD-1 checkpoint inhibitors to avoid delays in diagnosis and treatment. Based on pooled data from pivotal trials as reported by the European Medicines Agency, the present paper reviews incidences and kinetics of onset and resolution of immune-mediated "adverse events of specific interest" (AEOSI) of both approved PD-1 inhibitors nivolumab and pembrolizumab. In general, the severity of AEOSI is mild to moderate (grade 1-2); the frequency of immune-mediated but also idiopathic grade 3-4 adverse drug reactions is ⩽2% for any event term. Recommendations for the diagnosis, monitoring and management of the relevant dermatological, gastrointestinal, pulmonary, endocrine, renal and hepatic toxicities are convened by an expert panel that consolidated and clarified treatment recommendations after the onset of AEOSI. Although the time of onset is not predictable - the medians range from 1 to 6months - the huge majority of events is reversible, with no impact of the time of onset. By the systemic use of glucocorticoids, notably methylprednisolone or equivalents, most AEOSI are well manageable. Non-steroidal immunosuppressants may be used in certain cases of refractory/recalcitrant, long-lasting immune toxicities. With regard to the outstanding clinical activity of the anti-PD-1 antibodies, therapy restart is the principal therapeutic option after recovery of grade 2 AEOSI, or diminution of higher grade skin or endocrine events to mild severity. Early diagnosis and close clinical monitoring are essential for successful management of immune-related adverse events.

Checkpoint Inhibitors for the Treatment of Hodgkin Lymphoma

Hodgkin lymphoma's (HL) tumor composition is characterized by a paucity of malignant cells and a preponderance of immune and stromal cells. Despite the rich immune milieu within the tumor microenvironment, malignant cells are able to effectively evade the immune system and use immune support to promote lymphoma cell growth and proliferation. Recognizing this has led to the identification of checkpoint inhibitory signals that enable immune evasion and to opening the door to therapeutic strategies on how to exploit the immune system in targeting tumor cells. We discuss herein some of the tumor evasion mechanisms in HL with a particular focus on the immune checkpoint pathways and focus on recent clinical data of checkpoint blockade in HL treatment.

New Strategies in Bladder Cancer: A Second Coming for Immunotherapy

Urothelial bladder cancer (UBC) remains one of the most common and deadly cancers worldwide, and platinum-based chemotherapy, which has been the standard-of-care in metastatic bladder cancer, has had limited success in improving outcomes for patients. The recent development and translation of therapeutic strategies aimed at harnessing the immune system have led to durable and prolonged survival for patients with several different cancers, including UBC. In this review, we discuss new findings in bladder cancer immunotherapy, including recent successes with immune checkpoint blockade. We also discuss therapeutic cancer vaccines and highlight several additional immunotherapy modalities in early stages of development.

Vaccination with Irradiated Autologous Tumor Cells Mixed with Irradiated GM-K562 Cells Stimulates Antitumor Immunity and T Lymphocyte Activation in Patients with Recurrent Malignant Glioma

PURPOSE

Recurrent malignant glioma carries a dismal prognosis, and novel therapies are needed. We examined the feasibility and safety of vaccination with irradiated autologous glioma cells mixed with irradiated GM-K562 cells in patients undergoing craniotomy for recurrent malignant glioma.

EXPERIMENTAL DESIGN

We initiated a phase I study examining the safety of 2 doses of GM-K562 cells mixed with autologous cells. Primary endpoints were feasibility and safety. Feasibility was defined as the ability for 60% of enrolled subjects to initiate vaccination. Dose-limiting toxicity was assessed via a 3+3 dose-escalation format, examining irradiated tumor cells mixed with 5 × 10(6) GM-K562 cells or 1 × 10(7) GM-K562 cells. Eligibility required a priori indication for resection of a recurrent high-grade glioma. We measured biological activity by measuring delayed type hypersensitivity (DTH) responses, humoral immunity against tumor-associated antigens, and T-lymphocyte activation.

RESULTS

Eleven patients were enrolled. Sufficient numbers of autologous tumor cells were harvested in 10 patients, all of whom went on to receive vaccine. There were no dose-limiting toxicities. Vaccination strengthened DTH responses to irradiated autologous tumor cells in most patients, and vigorous humoral responses to tumor-associated angiogenic cytokines were seen as well. T-lymphocyte activation was seen with significantly increased expression of CTLA-4, PD-1, 4-1BB, and OX40 by CD4(+) cells and PD-1 and 4-1BB by CD8(+) cells. Activation was coupled with vaccine-associated increase in the frequency of regulatory CD4(+) T lymphocytes.

CONCLUSIONS

Vaccination with irradiated autologous tumor cells mixed with GM-K562 cells is feasible, well tolerated, and active in patients with recurrent malignant glioma. Clin Cancer Res; 22(12); 2885-96. ©2016 AACR.

Biology and treatment of BRAF mutant metastatic melanoma

BRAF inhibitors were among the first systemic therapies to show clinical benefit in metastatic melanoma. Here, we review the spectrum of BRAF mutations in melanoma, their role in oncogenesis, clinicopathological associations and response to treatment. The differing biology and clinical features of V600E- and V600K-mutated melanoma are outlined. The molecular changes associated with BRAF fusion genes and their response to targeted therapies, as well as the role of immunotherapy in treatment sequencing with targeted therapies are discussed.

CD44+ Cells in Head and Neck Squamous Cell Carcinoma Suppress T-Cell-Mediated Immunity by Selective Constitutive and Inducible Expression of PD-L1

PURPOSE

Human tumors consist of heterogeneous populations of cells with distinct marker expression and functional properties. In squamous cell carcinoma of the head and neck (SCCHN), CD44 is a well-characterized marker of a resilient subpopulation of cells associated with increased tumorigenesis, radioresistance, and chemoresistance. Evidence indicates that these cells have an immunosuppressive phenotype; however, mechanisms have been elusive.

EXPERIMENTAL DESIGN

Using primary human SCCHN tumor samples and patient-derived xenografts, we examined the phenotypes of subsets of tumor cells and investigated mechanisms regulating their immunogenicity.

RESULTS

CD44(+) cells in primary human SCCHN were found to have an epithelial-to-mesenchymal (EMT) phenotype and were less immunogenic than CD44(-) cells when cultured with autologous CD8(+) tumor-infiltrating T cells. Selective expression of the programmed death-ligand 1 (PD-L1) was observed on CD44(+) cells compared with CD44(-) cells and was associated with constitutive phosphorylation of STAT3 on CD44(+) cells. Importantly, inhibition of STAT3 decreased expression of PD-L1 on CD44(+) cells. IFNγ treatment preferentially induced even further PD-L1 expression on CD44(+) cells and was associated with enhanced IFNγ receptor expression and phosphorylation of STAT1. Finally, the decreased immunogenicity of CD44(+) cells was partially reversed by antibody blockade of the programmed death 1 (PD-1) receptor, indicating that the differences in PD-L1 expression between CD44(+) and CD44(-) cells are biologically and clinically relevant.

CONCLUSIONS

Our findings provide a mechanism by which long-lived CD44(+) tumor-initiating cells can selectively evade host immune responses and provide rationale for targeting the PD-1 pathway in the adjuvant therapy setting of SCCHN. Clin Cancer Res; 22(14); 3571-81. ©2016 AACR.

PD-L1 expression in cancer patients receiving anti PD-1/PD-L1 antibodies: A systematic review and meta-analysis

BACKGROUND

Despite the success of immunotherapy directed at inhibiting of programmed death-1 (PD-1)/PD-ligand (L)1 signaling, it is not established whether PD-L1 expression correlates with the clinical response and outcome in different tumors. The present meta-analysis investigates whether the PD-L1 status, detected by immunohistochemistry, is associated with clinical response and mortality in patients treated with anti-PD-1/PD-L1 therapy.

METHODS

A systematic literature search and quantitative analysis were planned, conducted and reported following CONSORT and QUORUM checklists, up to December 2015, to identify clinical trials with information on cancer outcome by PD-L1 immunohistochemical expression in tumor tissues. We used random effects models to estimate Summary Objective Response Rates (SORRs) and Summary Odd Ratio (SOR) for the comparison of PD-L1 positive and negative patients.

RESULTS

We summarized 20 trials carried out in metastatic melanoma (MM), non-small cell lung cancer (NSCLC), and renal cell carcinoma (RCC) patients receiving anti-PD-1/PD-L1 antibodies (4230 MM, 1417 NSCLC and 312 RCC patients). Positive PD-L1 MM patients showed a significant decrease (53%) in the risk of mortality vs. negative cases with no heterogeneity. Furthermore, SORRs were 45% and 27% in PD-L1 positive and negative patients, respectively, and SOR indicates a significant difference in term of responses: 2.14 (95% CI: 1.65, 2.77), with low between-study heterogeneity (I(2)=35%). Furthermore, results from randomized clinical trials on MM showed that PD-L1 expression is significantly associated with greater clinical response rates to anti-PD1 treatments (SOR 1.89; 95%CI: 1.35, 2.64) but not to other treatments (SOR 0.96; 95%CI: 0.5, 1.87). In non-squamous NSCLC SORRs were 29% and 11% in PD-L1 positive and negative patients, respectively, and SOR indicates a significant difference between responses: 3.78 (1.54, 9.24), with no between-study heterogeneity. Squamous NSCLC and RCC did not show any significant difference in response according to the PD-L1 status.

CONCLUSION

PD-L1 expression is significantly associated with mortality and clinical response to anti-PD-1/PD-L1 antibodies in MM patients and with clinical response in patients with non-squamous NSCLC.

Angiogenesis in melanoma: an update with a focus on current targeted therapies

Angiogenesis plays a crucial role in melanoma metastasis and progression. In recent years, numerous studies have investigated the prognostic and clinical significance of this phenomenon, and the development of molecular techniques has enabled us to achieve a better understanding of angiogenesis in melanoma. Herein, we review the current state of knowledge regarding angiogenesis in melanoma, including the pathophysiological, histological and immunohistochemical aspects of this phenomenon. We also review the molecular pathways involved in angiogenesis and the interplay between different components that might be manipulated in the future development of efficient targeted therapies. Recently developed targeted antiangiogenic therapies in clinical trials and included in the treatment of advanced-stage melanoma are also reviewed.

Combining targeted therapy with immunotherapy. Can 1+1 equal more than 2?

Targeted therapies have induced high response rates and improved survival in patients with cancer. However, the long-term effectiveness of targeted therapies has been limited by the development of acquired resistance in the majority of patients. On the other hand, the modern immunotherapy strategies have been associated with durable responses but in limited number of patients. Accordingly, research efforts have been focused on examining the effects of combinations of targeted therapy and immunotherapy in several different histological subtypes of cancer. There has been accumulated evidence to suggest that targeted therapy can induce immune effects in the tumor cells, the host immune system, and the tumor microenvironment. Subsequently, clinical trials have been designed to examine the efficacy of combining immune checkpoint blockade or adoptive cell transfer with tyrosine kinase inhibitors, HER family blockade, anti-angiogenic agents, histone deacetylase inhibitors, and cancer stem cell inhibitors. To date, the combination of immunotherapy with targeted therapy has demonstrated potential as a cancer treatment strategy, but further optimizations are required and caution must be taken to avoid toxicity. The current review summarizes existing evidence and provides rationale supporting the use of combined targeted and immune-therapy approaches in patients with different types of cancer.

Advances in immunotherapy for melanoma

In recent years, the introduction and Federal Drug Administration approval of immune checkpoint inhibitor antibodies has dramatically improved the clinical outcomes for patients with advanced melanoma. These antagonist monoclonal antibodies are capable of unleashing dormant or exhausted antitumor immunity, which has led to durable complete and partial responses in a large number of patients. Ipilimumab targets the cytotoxic T lymphocyte-associated protein 4 (CTLA-4) receptor. Nivolumab and pembrolizumab target programmed cell death protein 1 (PD-1) receptors and have proven to be superior to ipilimumab alone. The combination of ipilimumab and nivolumab has yielded higher response rates, greater tumor shrinkage, and longer progression-free survival than either monotherapy alone. As other promising immunotherapies for melanoma proceed through clinical trials, future goals include defining the role of immune checkpoint inhibitors as adjuvant therapy, identifying optimal combination strategies, and developing reliable predictive biomarkers to guide treatment selection for individual patients.

Management of toxicities of immune checkpoint inhibitors

Immune checkpoint inhibition with the anti-CTLA-4 antibody ipilimumab and the anti-PD-1 antibodies nivolumab and pembrolizumab has improved survival in metastatic melanoma, lung cancer and renal cancer. Use of these agents holds promise in other malignancies. The augmented immune response enabled by these agents has led to a particular group of side effects called immune-related adverse events (irAEs). The main irAEs include diarrhea, colitis, hepatitis, skin toxicities and endocrinopathies such as hypophysitis and thyroid dysfunction. The anti-PD-1 antibodies have a different toxicity profile to ipilimumab with fewer high grade events. This article identifies the rates of common and uncommon irAEs associated with each immune checkpoint inhibitor (ICPI) and their timing of onset, focusing mainly on the experience in melanoma and lung cancer. An approach to management for each class of irAE is provided.

Autologous melanoma cell vaccine using monocyte-derived dendritic cells (NBS20/eltrapuldencel-T)

Targeted therapy and immunotherapy have revolutionized the treatment of advanced melanoma. Despite recent advances, lack of long-term efficacy from targeted therapy and serious immune-related toxicity are major concerns. There is unmet need for 'durable' and 'safe' treatment options for advanced melanoma. Cancer vaccine therapy in melanoma has been investigated for many years with modest clinical efficacy. More recently, dendritic cell-based vaccine products have become available for clinical use and have been the focus of investigation. CLBS20 (NBS20/eltrapuldencel-T) is a novel dendritic cell-based vaccine product that has shown promising results in early phase trials in advanced melanoma. This cancer vaccine approach could play an important role in providing a sustainable survival benefit, targeting cancer cells themselves and avoiding off-target immune-related toxicity.

Importance of immunopharmacogenomics in cancer treatment: Patient selection and monitoring for immune checkpoint antibodies

In the last 5 years, immune checkpoint antibodies have become established as anticancer agents for various types of cancer. These antibody drugs, namely cytotoxic T-lymphocyte-associated antigen, programmed death-1, and programmed death ligand-1 antibodies, have revealed relatively high response rates, the ability to induce durable responses, and clinical efficacy in malignancies not previously thought to be susceptible to immune-based strategies. However, because of its unique mechanisms of activating the host immune system against cancer as well as expensive cost, immune checkpoint blockade faces novel challenges in selecting appropriate patient populations, monitoring clinical responses, and predicting immune adverse events. The development of objective criteria for selecting patient populations that are likely to have benefit from these therapies has been vigorously investigated but still remains unclear. In this review, we describe immune checkpoint inhibition-specific challenges with patient selection and monitoring, and focus on approaches to remedy these challenges. We also discuss applications of the emerging field of immunopharmacogenomics for guiding selection and monitoring for anti-immune checkpoint treatment.

CTLA-4 and PD-1 Pathways: Similarities, Differences, and Implications of Their Inhibition

The cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) and programmed death 1 (PD-1) immune checkpoints are negative regulators of T-cell immune function. Inhibition of these targets, resulting in increased activation of the immune system, has led to new immunotherapies for melanoma, non-small cell lung cancer, and other cancers. Ipilimumab, an inhibitor of CTLA-4, is approved for the treatment of advanced or unresectable melanoma. Nivolumab and pembrolizumab, both PD-1 inhibitors, are approved to treat patients with advanced or metastatic melanoma and patients with metastatic, refractory non-small cell lung cancer. In addition the combination of ipilimumab and nivolumab has been approved in patients with BRAF WT metastatic or unresectable melanoma. The roles of CTLA-4 and PD-1 in inhibiting immune responses, including antitumor responses, are largely distinct. CTLA-4 is thought to regulate T-cell proliferation early in an immune response, primarily in lymph nodes, whereas PD-1 suppresses T cells later in an immune response, primarily in peripheral tissues. The clinical profiles of immuno-oncology agents inhibiting these 2 checkpoints may vary based on their mechanistic differences. This article provides an overview of the CTLA-4 and PD-1 pathways and implications of their inhibition in cancer therapy.

Combination immune checkpoint blockade with ipilimumab and nivolumab in the management of advanced melanoma

INTRODUCTION

The use of immune checkpoint inhibitors for the treatment of advanced melanoma has evolved beyond monotherapies such as ipilimumab and nivolumab to combination strategies involving both. This combination approach results in response rates around 60% and superior progression-free survival compared with ipilimumab monotherapy (median 11.5 versus 2.9 months).

AREAS COVERED

A comprehensive literature search was undertaken including search terms of 'ipilimumab and nivolumab' and 'combination immune checkpoint therapy'. Relevant information contained in abstracts and conference presentations was included. This article summarizes the mechanism of action, efficacy and safety of combination ipilimumab and nivolumab across Phase I, II and III clinical trials. It also describes the place of combination therapy in the current market of advanced melanoma treatment options.

EXPERT OPINION

Efficacy for the combination approach is seen across a wide array of subgroups and occurs regardless of BRAF mutation status. Counterbalancing the apparent advantages, combination ipilimumab with nivolumab is associated with a high rate (55%) of grade 3/4 adverse events leading to discontinuation in a third of those treated. Most of these are manageable and do not appear to compromise durability of response. Overall survival information is currently immature but appears promising.

Immunotherapy for cancer in the central nervous system: Current and future directions

Glioblastoma multiforme (GBM) is the most common primary brain tumor in adults and still remains incurable. Although immunotherapeutic vaccination against GBM has demonstrated immune-stimulating activity with some promising survival benefits, tumor relapse is common, highlighting the need for additional and/or combinatorial approaches. Recently, antibodies targeting immune checkpoints were demonstrated to generate impressive clinical responses against advanced melanoma and other malignancies, in addition to showing potential for enhancing vaccination and radiotherapy (RT). Here, we summarize the current knowledge of central nervous system (CNS) immunosuppression, evaluate past and current immunotherapeutic trials and discuss promising future immunotherapeutic directions to treat CNS-localized malignancies.

Immune based therapy for melanoma

A few years ago therapeutic options in advanced melanoma were very limited and the prognosis was somber. Although recent progresses are far from providing a cure for advanced melanoma, yet these have kindled new hopes and searching for a cure does not seem unreasonable. Seven new medicines have been authorized in various regions of the world in the recent past in the therapy of advanced melanoma, over half of them acting by mechanisms involving the immune system of the host. The anti-CTLA-4 (cytotoxic T lymphocyte associated protein-4) ipilimumab has been followed by anti-PD1 (programmed death1) inhibitors, more effective and safer. Very recently, the first oncolytic immunotherapy, talimogene laherparepvec (T-VEC) has been authorized for placing on the market and a variety of combinations of the new therapies are currently being evaluated or considered. Besides, a plethora of other molecules and approaches, especially monoclonal antibodies, are in the preliminary phases of clinical investigation and are likely to bring new benefits for the treatment of this potentially fatal form of cancer.

Immune evasion pathways and the design of dendritic cell-based cancer vaccines

Emerging data is suggesting that the process of dendritic cell (DC) tolerization is an important step in tumorigenesis. Our understanding of the networks within the tumor microenvironment that functionally tolerize DC function is evolving while methods for genetically manipulating DC populations in situ continue to develop. A more intimate understanding of the paracrine signaling pathways which mediate immune evasion by subverting DC function promises to provide novel strategies for improving the clinical efficacy of DC-based cancer vaccines. This will likely require a better understanding of both the antigen expression profile and the immune evasion network of the tumor and its associated stromal tissues.

The impact of sequencing on diagnosis and treatment of malignant melanoma

Melanoma is one of the clinically most important cancer types considering its high mortality rate and that it is commonly diagnosed in relatively young people. With the advent of targeted therapies and, more recently, immune checkpoint inhibitors, more treatment options are available resulting in higher patient survival rates. However, the successful application of these targeted therapies critically depends on the reliable detection of molecular aberrations. Today, massively parallel sequencing techniques enable us to analyze large sets of genes in a relatively short time. It has allowed increased knowledge of acquired somatic mutations in melanoma and has helped to identify new targets for personalized therapy, and potentially may help to predict response to immune therapies. Described here are the development of sequencing techniques, how their improvement has changed diagnosis, prognosis and management of malignant melanoma and the future perspectives of melanoma diagnostics in the routine clinical setting.

Adoptive cell therapy: a highly successful individualized therapy for melanoma with great potential for other malignancies

Adoptive cell therapy (ACT) by infusion of autologous or redirected tumor-specific T-cells has had a major impact on the treatment of several metastasized malignancies that were until now hardly treatable. Recent findings provide a more profound knowledge on the underlying mechanisms of success and allow the optimization of the ACT protocol with respect to (1) the treatment related side-effects, (2) the quality and specificity of infused T-cells, and (3) the immunosuppressive phenotype of the tumor environment. In this review, the results and insights in the success of ACT as well as the possibilities to improve ACT and its exploitation as treatment option for various metastatic cancer types, will be discussed.