Vemurafenib in Patients With BRAF V600E Mutation–Positive Advanced Melanoma

Ocular adverse effects of anti-cancer chemotherapy

Cancer ranks as the second leading cause of mortality in Europe, following cardiovascular diseases. Every year, 2.6 million people are diagnosed with this disease, and 1.2 million die. It has an impact not only on individual health but also on society and the economy. The survival rate has improved with the introduction of new diagnostic methods and anti-cancer chemotherapy. While more aggressive chemotherapeutic regimens and combination therapies have demonstrated efficacy against cancer cells, they also have detrimental effects on normal cells, leading to systemic and ocular adverse reactions associated with cytotoxicity, inflammation, and neurotoxicity. Consequently, we have an increased survival rate, but the appearance of these ocular adverse effects decreases the quality of life. Ocular toxicity induced by chemotherapeutic agents is often underestimated. While prevention may not be possible, proper management by an ophthalmologist, an integral part of the oncology patient's medical team, is crucial. The ophthalmologist should assess the patient before initiating chemotherapeutic treatment and continue monitoring throughout to identify any adverse ocular reactions resulting from the systemic chemotherapy. This article aimed to briefly highlight the adverse reactions occurring at the ocular surface in patients undergoing chemotherapeutic treatment. Fortunately, these ocular side effects are limited only to the period in which the chemotherapeutic treatment is done, with most of them disappearing a few weeks after stopping the treatment.

Raman spectroscopy combined with deep learning for rapid detection of melanoma at the single cell level

Melanoma is an aggressive and metastatic skin cancer caused by genetic mutations in melanocytes, and its incidence is increasing year by year. Understanding the gene mutation information of melanoma cases is very important for its precise treatment. The current diagnostic methods for melanoma include radiological, pharmacological, histological, cytological and molecular techniques, but the gold standard for diagnosis is still pathological biopsy, which is time consuming and destructive. Raman spectroscopy is a rapid, sensitive and nondestructive detection method. In this study, a total of 20,000 Surface-enhanced Raman scattering (SERS) spectra of melanocytes and melanoma cells were collected using a positively charged gold nanoparticles planar solid SERS substrate, and a classification network system based on convolutional neural networks (CNN) was constructed to achieve the classification of melanocytes and melanoma cells, wild-type and mutant melanoma cells and their drug resistance. Among them, the classification accuracy of melanocytes and melanoma cells was over 98%. Raman spectral differences between melanocytes and melanoma cells were analyzed and compared, and the response of cells to antitumor drugs were also evaluated. The results showed that Raman spectroscopy provided a basis for the medication of melanoma, and SERS spectra combined with CNN classification model realized classification of melanoma, which is of great significance for rapid diagnosis and identification of melanoma.

Caffeine improves the cytotoxic effect of dacarbazine on B16F10 murine melanoma cells

OBJECTIVE

Caffeine has been studied as a potentiating agent in chemotherapy against some types of cancer, but there are few reports on its effects on melanoma. This study aimed to investigate caffeine's ability to enhance the effects of dacarbazine in vitro.

MATERIALS AND METHODS

Murine melanoma B16F10 cells were treated 24 h with 1-40 µM caffeine. We evaluated cytotoxicity, DNA damage, apoptosis, and oxidative lesion induced by dacarbazine associated with caffeine. The metabolization of these drugs, as well as immunocytochemical labeling, were also evaluated.

CONCLUSIONS

The pre-treatment with caffeine showed to be more effective. Caffeine potentiated dacarbazine-induced cytotoxic effects by increasing dacarbazine biotransformation, apoptosis, DNA damage, and malondialdehyde levels; also, caffeine reduced Ki67 and ERK1/2 nuclear labeling and increased p53 labeling in B16F10 cells. In our experiment, caffeine promoted modifications associated with dacarbazine metabolism by viable cells potentiating this antineoplastic drug. These promising results should be further evaluated in experimental models in vivo.

Dermatologic adverse events associated with targeted therapies for melanoma

INTRODUCTION

The development of new targeted therapies has considerably changed the therapeutic paradigm of melanoma, significantly increasing overall survival (OS) and progression-free survival (PFS). However, skin-related adverse sequelae might occur and impact on patients' quality of life.

AREAS COVERED

In this article we will cover the most important dermatological toxicities related to BRAF and MEK-inhibitors, along with updated management strategies.

EXPERT OPINION

BRAF inhibitors have represented a revolution in the treatment of melanoma. They have improved the outcome of the disease and therefore represent an important option in the management and care of patients with advanced melanoma. Skin toxicity (especially the onset of squamous skin carcinomas) has been considered a major cutaneous side effect and, although the addition of MEK inhibitors in combination has significantly reduced the incidence of skin sequelae, serious skin adverse events might develop anyway and impact significantly on patients'quality of life and on national health system budget. The introduction of BRAF and MEK inhibitors as a new effective adjuvant treatment option for stage III and ulcerated melanoma has proved a significant impact on the risk of recurrence, and may have interesting developments in the near future as a further therapeutic tool.

Phenformin and ataxia-telangiectasia mutated inhibitors synergistically co-suppress liver cancer cell growth by damaging mitochondria

Inhibitors of ataxia–telangiectasia mutated (ATM), such as KU‐55933 (Ku), represent a promising class of novel anticancer drugs. In addition, the biguanide derivative phenformin exhibits antitumor activity superior to that of the AMPK activator metformin. Herein, we assessed the potential combinatorial therapeutic efficacy of phenformin and Ku when used to inhibit the growth of liver cancer cells, and we assessed the mechanisms underlying such efficacy. The Hep‐G2 and SMMC‐7721 liver cancer cell lines were treated with phenformin and Ku either alone or in combination, after which the impact of these drugs on cellular proliferation was assessed via 3‐(4,5‐dimethylthiazol) 2, 5‐diphenyltetrazolium and colony formation assays, whereas Transwell assays were used to gauge cell migratory activity. The potential synergy between these two drugs was assessed using the compusyn software, while flow cytometry was employed to evaluate cellular apoptosis. In addition, western blotting was utilized to measure p‐ATM, p‐AMPK, p‐mTOR, and p‐p70s6k expression, while mitochondrial functionality was monitored via morphological analyses, JC‐1 staining, and measurements of ATP levels. Phenformin and Ku synergistically impacted the proliferation, migration, and apoptotic death of liver cancer cells. Together, these compounds were able to enhance AMPK phosphorylation while inhibiting the phosphorylation of mTOR and p70s6k. These data also revealed that phenformin and Ku induced mitochondrial dysfunction as evidenced by impaired ATP synthesis, mitochondrial membrane potential, and abnormal mitochondrial morphology. These findings suggest that combination treatment with phenformin and Ku may be an effective approach to treating liver cancer via damaging mitochondria within these tumor cells.

Combining evidence for and against pathogenicity for variants in cancer susceptibility genes: CanVIG-UK consensus recommendations

Accurate classification of variants in cancer susceptibility genes (CSGs) is key for correct estimation of cancer risk and management of patients. Consistency in the weighting assigned to individual elements of evidence has been much improved by the American College of Medical Genetics (ACMG) 2015 framework for variant classification, UK Association for Clinical Genomic Science (UK-ACGS) Best Practice Guidelines and subsequent Cancer Variant Interpretation Group UK (CanVIG-UK) consensus specification for CSGs. However, considerable inconsistency persists regarding practice in the combination of evidence elements. CanVIG-UK is a national subspecialist multidisciplinary network for cancer susceptibility genomic variant interpretation, comprising clinical scientist and clinical geneticist representation from each of the 25 diagnostic laboratories/clinical genetic units across the UK and Republic of Ireland. Here, we summarise the aggregated evidence elements and combinations possible within different variant classification schemata currently employed for CSGs (ACMG, UK-ACGS, CanVIG-UK and ClinGen gene-specific guidance for PTEN, TP53 and CDH1). We present consensus recommendations from CanVIG-UK regarding (1) consistent scoring for combinations of evidence elements using a validated numerical 'exponent score' (2) new combinations of evidence elements constituting likely pathogenic' and 'pathogenic' classification categories, (3) which evidence elements can and cannot be used in combination for specific variant types and (4) classification of variants for which there are evidence elements for both pathogenicity and benignity.

From Conventional Therapies to Immunotherapy: Melanoma Treatment in Review

Simple Summary

Here, we review the current state of knowledge in the field of cancer immunotherapy, focusing on the scientific rationale for the use of oncolytic viruses, checkpoint inhibitors and their combination to combat melanomas. Attention is also given to the immunological aspects of cancer therapy and the shift from conventional therapy towards immunotherapy. This review brings together information on how immunotherapy can be applied to support other cancer therapies in order to maximize the efficacy of melanoma treatment and improve clinical outcomes.

Abstract

In this review, we discuss the use of oncolytic viruses and checkpoint inhibitors in cancer immunotherapy in melanoma, with a particular focus on combinatory therapies. Oncolytic viruses are promising and novel anti-cancer agents, currently under investigation in many clinical trials both as monotherapy and in combination with other therapeutics. They have shown the ability to exhibit synergistic anticancer activity with checkpoint inhibitors, chemotherapy, radiotherapy. A coupling between oncolytic viruses and checkpoint inhibitors is a well-accepted strategy for future cancer therapies. However, eradicating advanced cancers and tailoring the immune response for complete tumor clearance is an ongoing problem. Despite current advances in cancer research, monotherapy has shown limited efficacy against solid tumors. Therefore, current improvements in virus targeting, genetic modification, enhanced immunogenicity, improved oncolytic properties and combination strategies have a potential to widen the applications of immuno-oncology (IO) in cancer treatment. Here, we summarize the strategy of combinatory therapy with an oncolytic vector to combat melanoma and highlight the need to optimize current practices and improve clinical outcomes.

Dual Inhibition of MAPK and JAK2/STAT3 Pathways Is Critical for the Treatment of BRAF Mutant Melanoma

BRAF and MEK inhibitors significantly prolong progression-free survival in patients with BRAF mutant melanoma. However, most patients quickly develop drug resistance. The mechanism of drug resistance is complicated and remains to be further explored. Here, we found that inhibition of the MAPK pathway activates the Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway, whereas JAK2 inhibitors that inhibit the JAK2/STAT3 pathway activate the MAPK pathway, suggesting a crosstalk between these two pathways in BRAF mutant melanoma cells. Reactivation of the MAPK pathway occurs in most drug-resistant patients with BRAF mutations. Therefore, dual inhibition of the MAPK and JAK2/STAT3 pathways is critical for the treatment of BRAF mutant melanoma. However, we found that the combination of BRAF, MEK inhibitors, and JAK2 or STAT3 inhibitors could not simultaneously inhibit the MAPK and JAK2/STAT3 pathways in BRAF mutant melanoma cells. Subsequently, we found that a combination of all three MAPK pathway inhibitors—BRAF, MEK, and ERK inhibitors—with JAK2 or STAT3 inhibitors can dually inhibit the MAPK and JAK2/STAT3 pathways, showing a significant inhibition of the growth of BRAF mutant melanoma cells compared with either treatment alone. Therefore, dual inhibition of MAPK and JAK2/STAT3 pathways may be a novel strategy for the treatment of BRAF mutant tumors.

Transcripts 202 and 205 of IL-6 confer resistance to Vemurafenib by reactivating the MAPK pathway in BRAF(V600E) mutant melanoma cells

BRAF mutations occur in approximately 50% of melanoma patients. The mutated BRAF kinase continuously activates the mitogen-activated protein kinase (MAPK) pathway to promote cell growth and proliferation. Vemurafenib as a specific BRAF inhibitor can significantly prolong progression-free survival in melanoma patients. However, most patients developed resistance to Vemurafenib after 6 months. The mechanism of drug resistance is not yet fully understood. In this study, we found that proteins secreted by drug-resistant cells protect sensitive cells from Vemurafenib. By RNA-seq, we compared differentially expressed genes between resistant and sensitive cells. We demonstrated that drug-resistant cells secrete more IL-6 protein than sensitive cells. For the first time, we found that IL-6 expressed by drug-resistant cells consists of the following transcripts: IL6-201, IL6-202 and IL6-205. We confirmed that it is the IL6-202 and IL6-205 transcripts that confer drug resistance to Vemurafenib by reactivating the MAPK pathway while IL6-201 is not responsible for the resistance in A375 melanoma cells. Neutralizing IL-6 significantly increased the sensitivity of drug-resistant cells to Vemurafenib. Overall, these results reveal a new mechanism of drug resistance in melanoma.

Phenformin as an Anticancer Agent: Challenges and Prospects

Currently, there is increasing evidence linking diabetes mellitus (especially type 2 diabetes mellitus) with carcinogenesis through various biological processes, such as fat-induced chronic inflammation, hyperglycemia, hyperinsulinemia, and angiogenesis. Chemotherapeutic agents are used in the treatment of cancer, but in most cases, patients develop resistance. Phenformin, an oral biguanide drug used to treat type 2 diabetes mellitus, was removed from the market due to a high risk of fatal lactic acidosis. However, it has been shown that phenformin is, with other biguanides, an authentic tumor disruptor, not only by the production of hypoglycemia due to caloric restriction through AMP-activated protein kinase with energy detection (AMPK) but also as a blocker of the mTOR regulatory complex. Moreover, the addition of phenformin eliminates resistance to antiangiogenic tyrosine kinase inhibitors (TKI), which prevent the uncontrolled metabolism of glucose in tumor cells. In this review, we evidence the great potential of phenformin as an anticancer agent. We thoroughly review its mechanism of action and clinical trial assays, specially focusing on current challenges and future perspectives of this promising drug.

Integrating precision medicine through evaluation of cell of origin in treatment planning for diffuse large B-cell lymphoma

Precision medicine is modernizing strategies for clinical study design to help improve diagnoses guiding individualized treatment based on genetic or phenotypic characteristics that discriminate between patients with similar clinical presentations. Methodology to personalize treatment choices is being increasingly employed in clinical trials, yielding favorable correlations with improved response rates and survival. In patients with diffuse large B-cell lymphoma (DLBCL), disease characteristics and outcomes may vary widely, underscoring the importance of patient classification through identification of sensitive prognostic features. The discovery of distinct DLBCL molecular subtypes based on cell of origin (COO) is redefining the prognosis and treatment of this heterogeneous cancer. Owing to significant molecular and clinical differences between activated B-cell-like (ABC)- and germinal center B-cell-like (GCB)-DLBCL subtypes, COO identification offers opportunities to optimize treatment selection. Widespread adoption of COO classification would greatly improve treatment and prognosis; however, limitations in interlaboratory concordance between immunohistochemistry techniques, cost, and availability of gene expression profiling tools undermine universal integration in the clinical setting. With advanced methodology to determine COO in a real-world clinical setting, therapies targeted to specific subtypes are under development. The focus here is to review applications of precision medicine exemplified by COO determination in DLBCL patients.

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

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

Identification and functional analysis of SOX10 phosphorylation sites in melanoma

The transcription factor SOX10 plays an important role in vertebrate neural crest development, including the establishment and maintenance of the melanocyte lineage. SOX10 is also highly expressed in melanoma tumors, and SOX10 expression increases with tumor progression. The suppression of SOX10 in melanoma cells activates TGF-β signaling and can promote resistance to BRAF and MEK inhibitors. Since resistance to BRAF/MEK inhibitors is seen in the majority of melanoma patients, there is an immediate need to assess the underlying biology that mediates resistance and to identify new targets for combinatorial therapeutic approaches. Previously, we demonstrated that SOX10 protein is required for tumor initiation, maintenance and survival. Here, we present data that support phosphorylation as a mechanism employed by melanoma cells to tightly regulate SOX10 expression. Mass spectrometry identified eight phosphorylation sites contained within SOX10, three of which (S24, S45 and T240) were selected for further analysis based on their location within predicted MAPK/CDK binding motifs. SOX10 mutations were generated at these phosphorylation sites to assess their impact on SOX10 protein function in melanoma cells, including transcriptional activation on target promoters, subcellular localization, and stability. These data further our understanding of SOX10 protein regulation and provide critical information for identification of molecular pathways that modulate SOX10 protein levels in melanoma, with the ultimate goal of discovering novel targets for more effective combinatorial therapeutic approaches for melanoma patients.

Precision oncology: neither a silver bullet nor a dream

Precision oncology is not an illusion, nor is it the magic bullet that will eradicate all cancers. Precision oncology is simply another weapon in our growing armament against cancer. Rather than honing in on the failures of a relatively young field, one should advocate for integrating its successes into widespread clinical practice, especially for indications, such as: ABL, ALK, BRAF, BRCA1, BRCA2, EGFR, KIT, KRAS, PDGFRA, PDGFRB, ROS1, BCR-ABL, FLT3 and ROS1, where aberrations have been shown to alter responses to US FDA approved drugs - that is, level 1 data. Moreover, to truly assess the promise of precision oncology, we must first begin by defining our expectations for this field. Importantly, we must recognize that the conception of precision oncology arose as an antithesis of the 'one-size fits all' cancer therapeutics approach. Consequently, tools used for evaluating these conventional, large-scale trials, are not directly transferable for assessing nonconventional, smaller-scale trials needed for evaluating precision oncology. Hence, a thorough vetting of precision oncology as another tool of the trade, must first begin by reassessing our expectations for this field, as well as current clinical trial designs and end point measurements. Importantly, we must recognize that most targeted therapy approaches are in their infancy, with only monotherapy approaches being assessed and combination therapies likely being necessary to fulfill the promise of precision oncology.

Therapeutic Inhibitors against Mutated BRAF and MEK for the Treatment of Metastatic Melanoma

Melanoma is one of the most aggressive cancers in the world and is responsible for the majority of skin cancer deaths. Recent advances in the field of immunotherapy using active, adoptive, and antigen-specific therapeutic approaches, have generated the expectation that these technologies have the potential to improve the treatment of advanced malignancies, including melanoma. Treatment options for metastatic melanoma patients have been dramatically improved by the FDA approval of new therapeutic agents including vemurafenib, dabrafenib, and sorafenib. These kinase inhibitors have the potential to work in tandem with MEK, PI3K/AKT, and mTOR to inhibit the activity of melanoma inducing BRAF mutations. This review summarizes the effects of the new therapeutic agents against melanoma and the underlying biology of these BRAF inhibitors.

Droplet-Based Digital PCR: Application in Cancer Research

The efficient characterization of genetic and epigenetic alterations in oncology, virology, or prenatal diagnostics requires highly sensitive and specific high-throughput approaches. Nevertheless, with the use of conventional methods, sensitivity and specificity were largely limited. By partitioning individual target molecules within distinct compartments, digital PCR (dPCR) could overcome these limitations and detect very rare sequences with unprecedented precision and sensitivity. In dPCR, the sample is diluted such that each individual partition will contain no more than one target sequence. Following the assay reaction, the dPCR process provides an absolute value and analyzable quantitative data. The recent coupling of dPCR with microfluidic systems in commercial platforms should lead to an essential tool for the management of patients with cancer, especially adapted to the analysis of precious samples. Applications in cancer research range from the analysis of tumor heterogeneity to that of a range of body fluids. Droplet-based dPCR is indeed particularly appropriate for the emerging field of liquid biopsy analysis. In this review, following an overview of the development in dPCR technology and different strategies based on the use of microcompartments, we will focus particularly on the applications and latest development of microfluidic droplet-based dPCR in oncology.

Negative feedback regulation of the ERK1/2 MAPK pathway

The extracellular signal-regulated kinase 1/2 (ERK1/2) mitogen-activated protein kinase (MAPK) signalling pathway regulates many cellular functions, including proliferation, differentiation, and transformation. To reliably convert external stimuli into specific cellular responses and to adapt to environmental circumstances, the pathway must be integrated into the overall signalling activity of the cell. Multiple mechanisms have evolved to perform this role. In this review, we will focus on negative feedback mechanisms and examine how they shape ERK1/2 MAPK signalling. We will first discuss the extensive number of negative feedback loops targeting the different components of the ERK1/2 MAPK cascade, specifically the direct posttranslational modification of pathway components by downstream protein kinases and the induction of de novo gene synthesis of specific pathway inhibitors. We will then evaluate how negative feedback modulates the spatiotemporal signalling dynamics of the ERK1/2 pathway regarding signalling amplitude and duration as well as subcellular localisation. Aberrant ERK1/2 activation results in deregulated proliferation and malignant transformation in model systems and is commonly observed in human tumours. Inhibition of the ERK1/2 pathway thus represents an attractive target for the treatment of malignant tumours with increased ERK1/2 activity. We will, therefore, discuss the effect of ERK1/2 MAPK feedback regulation on cancer treatment and how it contributes to reduced clinical efficacy of therapeutic agents and the development of drug resistance.

A Pilot Trial of the Combination of Vemurafenib with Adoptive Cell Therapy in Patients with Metastatic Melanoma

PURPOSE

This pilot feasibility clinical trial evaluated the coadministration of vemurafenib, a small-molecule antagonist of BRAF^V600 mutations, and tumor-infiltrating lymphocytes (TIL) for the treatment of metastatic melanoma.

EXPERIMENTAL DESIGN

A metastatic tumor was resected for growth of TILs, and patients were treated with vemurafenib for 2 weeks, followed by resection of a second lesion. Patients then received a nonmyeloablative preconditioning regimen, infusion of autologous TILs, and high-dose interleukin-2 administration. Vemurafenib was restarted at the time of TIL infusion and was continued for 2 years or until disease progression. Clinical responses were evaluated by Response Evaluation Criteria in Solid Tumors (RECIST) 1.0. Metastases resected prior to and after 2 weeks of vemurafenib were compared using TCRB deep sequencing, immunohistochemistry, proliferation, and recognition of autologous tumor.

RESULTS

The treatment was well tolerated and had a safety profile similar to that of TIL or vemurafenib alone. Seven of 11 patients (64%) experienced an objective clinical response, and 2 patients (18%) had a complete response for 3 years (one response is ongoing at 46 months). Proliferation and viability of infusion bag TILs and peripheral blood T cells were inhibited in vitro by research-grade vemurafenib (PLX4032) when approaching the maximum serum concentration of vemurafenib. TCRB repertoire (clonotypes numbers, clonality, and frequency) did not significantly change between pre- and post-vemurafenib lesions. Recognition of autologous tumor by T cells was similar between TILs grown from pre- and post-vemurafenib metastases.

CONCLUSIONS

Coadministration of vemurafenib and TILs was safe and feasible and generated objective clinical responses in this small pilot clinical trial. Clin Cancer Res; 23(2); 351-62. ©2016 AACRSee related commentary by Cogdill et al., p. 327.

Fast Diagnostics of BRAF Mutations in Biopsies from Malignant Melanoma

According to the American skin cancer foundation, there are more new cases of skin cancer than the combined incidence of cancers of the breast, prostate, lung, and colon each year, and malignant melanoma represents its deadliest form. About 50% of all cases are characterized by a particular mutation BRAF(V600E) in the BRAF (Rapid Acceleration of Fibrosarcoma gene B) gene. Recently developed highly specific drugs are able to fight BRAF(V600E) mutated tumors but require diagnostic tools for fast and reliable mutation detection to warrant treatment efficiency. We completed a preliminary clinical trial applying cantilever array sensors to demonstrate identification of a BRAF(V600E) single-point mutation using total RNA obtained from biopsies of metastatic melanoma of diverse sources (surgical material either frozen or fixated with formalin and embedded in paraffin). The method is faster than the standard Sanger or pyrosequencing methods and comparably sensitive as next-generation sequencing. Processing time from biopsy to diagnosis is below 1 day and does not require PCR amplification, sequencing, and labels.

Altered Morphology and Immunohistochemical Characteristics in Metastatic Malignant Melanoma After Therapy With Vemurafenib

Metastatic melanoma is traditionally diagnosed using classic morphologic features in addition to immunohistochemical studies. The authors report a case of metastatic malignant melanoma where both morphology and immunohistochemistry were altered after treatment. This 51-year-old patient presented with metastatic melanoma to the brain and axilla. Initially, both metastases showed classic morphology and diffuse staining with the pan-melanoma antibody cocktail. This cocktail is a combination of 3 antibodies commonly used to diagnose melanocytic neoplasms: Melan-A (MART-1), tyrosinase, and HMB-45. In combination, the cocktail is highly sensitive for detecting melanocytic neoplasms and is commonly used to diagnose metastatic melanoma. Her tumor was positive for the BRAF 1799T>A (V600E) mutation, and she was treated with BRAF inhibitor therapy (vemurafenib). However, the axillary tumor recurred after treatment with vemurafenib. The recurrent tumor showed a markedly different morphology and complete loss of staining with the pan-melanoma antibody cocktail. This loss of staining accompanied by the change in morphology was an observation not previously documented after therapy with vemurafenib. This case demonstrates a potential pitfall in the diagnosis of metastatic or recurrent malignant melanoma.

Genomically Driven Tumors and Actionability across Histologies: BRAF-Mutant Cancers as a Paradigm

The diagnosis, classification, and management of cancer are traditionally dictated by the site of tumor origin, for example, breast or lung, and by specific histologic subtypes of site-of-origin cancers (e.g., non-small cell versus small cell lung cancer). However, with the advent of sequencing technologies allowing for rapid, low cost, and accurate sequencing of clinical samples, new observations suggest an expanded or different approach to the diagnosis and treatment of cancer-one driven by the unique molecular features of the tumor. We discuss a genomically driven strategy for cancer treatment using BRAF as an example. Several key points are highlighted: (i) molecular aberrations can be shared across cancers; (ii) approximately 15% of all cancers harbor BRAF mutations; and (iii) BRAF inhibitors, while approved only for melanoma, have reported activity across numerous cancers and related disease types bearing BRAF aberrations. However, BRAF-mutated colorectal cancer has shown poor response rate to BRAF inhibitor monotherapy, striking a cautionary note. Yet, even in this case, emerging data suggest BRAF-mutated colorectal cancers can respond well to BRAF inhibitors, albeit when administered in combination with other agents that impact resistance pathways. Taken together, these data suggest that molecular aberrations may be the basis for a new nosology for cancer. Mol Cancer Ther; 15(4); 533-47. ©2016 AACR.

Encorafenib (LGX818), a potent BRAF inhibitor, induces senescence accompanied by autophagy in BRAFV600E melanoma cells

Encorafenib (LGX818) is a new-generation BRAF inhibitor that is under evaluation in clinical trials. However, the underlying mechanism remains to be elucidated. Here we show that LGX818 potently decreased ERK phosphorylation and inhibited proliferation in BRAFV600E melanoma cell lines. Moreover, LGX818 downregulated CyclinD1 in a glycogen synthase kinase 3β-independent manner and induced cell cycle arrest in the G1 phase, Surprisingly, LGX818 triggered cellular senescence in BRAFV600E melanoma cells, as evidenced by increased β-galactosidase staining, while no appreciable induction of apoptosis was detected, as determined by Annexin V and propidium iodide staining and immunoblot analysis of caspase-3 processing and poly (ADP-ribose) polymerase cleavage. Increased p27KIP1 expression and retinoblastoma protein activation were detected during LGX818-induced senescence. Additionally, inhibition of dual-specificity tyrosine phosphorylation-regulated kinase 1B by AZ191 reversed LGX818-induced CyclinD1 turnover and senescence. Interestingly, autophagy is triggered through inhibition of the mTOR/70S6K pathway during LGX818-induced senescence. Moreover, autophagy inhibition by pharmacological and genetic regulation attenuates LGX818-induced senescence. Notably, combining LGX818 with autophagy modulators has anti-proliferative effect in LGX818-resistant BRAF mutant melanoma cells. Altogether, we uncovered a mechanism by which LGX818 exerts its anti-tumor activity in BRAFV600E melanoma cells.

Quantitative Detection and Resolution of BRAF V600 Status in Colorectal Cancer Using Droplet Digital PCR and a Novel Wild-Type Negative Assay

A need exists for robust and cost-effective assays to detect a single or small set of actionable point mutations, or a complete set of clinically informative mutant alleles. Knowledge of these mutations can be used to alert the clinician to a rare mutation that might necessitate more aggressive clinical monitoring or a personalized course of treatment. An example is BRAF, a (proto)oncogene susceptible to either common or rare mutations in codon V600 and adjacent codons. We report a diagnostic technology that leverages the unique capabilities of droplet digital PCR to achieve not only accurate and sensitive detection of BRAF(V600E) but also all known somatic point mutations within the BRAF V600 codon. The simple and inexpensive two-well droplet digital PCR assay uses a chimeric locked nucleic acid/DNA probe against wild-type BRAF and a novel wild-type-negative screening paradigm. The assay shows complete diagnostic accuracy when applied to formalin-fixed, paraffin-embedded tumor specimens from metastatic colorectal cancer patients deficient for Mut L homologue-1.

Response of metastatic glioma to vemurafenib

Extraneural metastatic disease of glioma is rare and poses unique therapeutic challenges. Increasingly, the ability to sequence genetic alterations in tumors has allowed for the identification of common oncogenic signatures such as the activating BRAF^V600E mutation and may be useful in therapeutic decision making. We report two patients with widespread aggressive gliomas whose tumors were found to express the BRAF^V600E mutation and then responded robustly albeit transiently when exposed to vemurafenib. Although both patients succumbed to their disease, our results suggest that targeting BRAF might be appropriate for patients with aggressive gliomas that express this mutation.

BRAF mutation testing in solid tumors: a methodological comparison

Solid tumor genotyping has become standard of care for the characterization of proto-oncogene mutational status, which has traditionally been accomplished with Sanger sequencing. However, companion diagnostic assays and comparable laboratory-developed tests are becoming increasingly popular, such as the cobas 4800 BRAF V600 Mutation Test and the INFINITI KRAS-BRAF assay, respectively. This study evaluates and validates the analytical performance of the INFINITI KRAS-BRAF assay and compares concordance of BRAF status with two reference assays, the cobas test and Sanger sequencing. DNA extraction from FFPE tissue specimens was performed followed by multiplex PCR amplification and fluorescent label incorporation using allele-specific primer extension. Hybridization to a microarray, signal detection, and analysis were then performed. The limits of detection were determined by testing dilutions of mutant BRAF alleles within wild-type background DNA, and accuracy was calculated based on these results. The INFINITI KRAS-BRAF assay produced 100% concordance with the cobas test and Sanger sequencing and had sensitivity equivalent to the cobas assay. The INFINITI assay is repeatable with at least 95% accuracy in the detection of mutant and wild-type BRAF alleles. These results confirm that the INFINITI KRAS-BRAF assay is comparable to traditional sequencing and the Food and Drug Administration-approved companion diagnostic assay for the detection of BRAF mutations.

Personalized medicine for gastroenteropancreatic neuroendocrine tumors: a distant dream?

Neuroendocrine tumors are heterogeneous cancers that can present with advanced disease. Treatment stratification is often based on limited characterization of tumor behavior from histological grade and imaging assessments. Personalized medicine strategies focus on tailoring therapy through characterization of cancer pathways and the development of biomarkers. This review article explores the current personalized medicine landscape in gastroenteropancreatic neuroendocrine tumors, from tissue and circulating biomarkers development through to tumor heterogeneity and reimbursement issues.

Unmet clinical needs in the management of advanced melanoma: findings from a survey of oncologists

Advanced melanoma is a life-threatening cancer with limited life expectancy. The recent introduction of new targeted systemic therapies has provided clinicians with the means to potentially extend survival for the first time. However, the chance of cure remains very low and treatment-induced toxicity is well described. This qualitative study was undertaken to evaluate clinicians' assessment regarding the key concerns in managing advanced melanoma following the introduction of these new treatments. Three hundred and forty-three oncologists were surveyed online between August and November 2012 (in 11 countries) and March and April 2013 (in an additional country). Analysis of free-text responses identified 23 clinical issues of concern across all countries. Of these, the most common clinical concerns were drug toxicity and tolerability, followed by limited treatment effectiveness and limited treatment options. These results suggest that despite the promise of the two new agents in the field, clinicians are still concerned about the limitations of current treatment options, recognising that there remains a significant unmet need in the treatment of advanced melanoma.

Next-Generation Genotyping by Digital PCR to Detect and Quantify the BRAF V600E Mutation in Melanoma Biopsies

The detection of the BRAF V600E mutation in melanoma samples is used to select patients who should respond to BRAF inhibitors. Different techniques are routinely used to determine BRAF status in clinical samples. However, low tumor cellularity and tumor heterogeneity can affect the sensitivity of somatic mutation detection. Digital PCR (dPCR) is a next-generation genotyping method that clonally amplifies nucleic acids and allows the detection and quantification of rare mutations. Our aim was to evaluate the clinical routine performance of a new dPCR-based test to detect and quantify BRAF mutation load in 47 paraffin-embedded cutaneous melanoma biopsies. We compared the results obtained by dPCR with high-resolution melting curve analysis and pyrosequencing or with one of the allele-specific PCR methods available on the market. dPCR showed the lowest limit of detection. dPCR and allele-specific amplification detected the highest number of mutated samples. For the BRAF mutation load quantification both dPCR and pyrosequencing gave similar results with strong disparities in allele frequencies in the 47 tumor samples under study (from 0.7% to 79% of BRAF V600E mutations/sample). In conclusion, the four methods showed a high degree of concordance. dPCR was the more-sensitive method to reliably and easily detect mutations. Both pyrosequencing and dPCR could quantify the mutation load in heterogeneous tumor samples.

Treatment patterns in advanced melanoma: findings from a survey of European oncologists

With the emergence of new therapies, established patterns of treating advanced melanoma are changing. The aim of this study was to understand how advanced melanoma is treated in clinical practice in Europe following the introduction of ipilimumab and vemurafenib. An online survey was conducted between August and November 2012 with 150 oncologists and dermatologists, from France, Germany, Italy, Spain and the U.K.; respondents reported treating the majority of patients with one or two lines of therapy. For BRAF mutant melanoma, the most frequently used first-line treatments were vemurafenib and dacarbazine. For BRAF wild-type melanoma, the most frequently used first-line treatment was dacarbazine. There was no single preferred agent for the second-line treatment of BRAF mutant or BRAF wild-type disease. Most sequencing from first- to second-line was from conventional dacarbazine to newer agents such as ipilimumab and vemurafenib. The treatment of advanced melanoma is rapidly evolving due to the introduction of new agents. This study presents an early insight into access to the new agents, ipilimumab and vemurafenib, and clinical practice in several European countries.

BRAF Inhibition Decreases Cellular Glucose Uptake in Melanoma in Association with Reduction in Cell Volume

BRAF kinase inhibitors have dramatically affected treatment of BRAF(V600E) (/) (K)-driven metastatic melanoma. Early responses assessed using [(18)F]fluorodeoxyglucose uptake-positron emission tomography (FDG-PET) have shown dramatic reduction of radiotracer signal within 2 weeks of treatment. Despite high response rates, relapse occurs in nearly all cases, frequently at sites of treated metastatic disease. It remains unclear whether initial loss of (18)FDG uptake is due to tumor cell death or other reasons. Here, we provide evidence of melanoma cell volume reduction in a patient cohort treated with BRAF inhibitors. We present data demonstrating that BRAF inhibition reduces melanoma glucose uptake per cell, but that this change is no longer significant following normalization for cell volume changes. We also demonstrate that volume normalization greatly reduces differences in transmembrane glucose transport and hexokinase-mediated phosphorylation. Mechanistic studies suggest that this loss of cell volume is due in large part to decreases in new protein translation as a consequence of vemurafenib treatment. Ultimately, our findings suggest that cell volume regulation constitutes an important physiologic parameter that may significantly contribute to radiographic changes observed in clinic.

PD-1 pathway inhibitors: the next generation of immunotherapy for advanced melanoma

Checkpoint inhibitors are revolutionizing treatment options and expectations for patients with melanoma. Ipilimumab, a monoclonal antibody against cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4), was the first approved checkpoint inhibitor. Emerging long-term data indicate that approximately 20% of ipilimumab-treated patients achieve long-term survival. The first programmed death 1 (PD-1) inhibitor, pembrolizumab, was recently approved by the United States Food and Drug Administration for the treatment of melanoma; nivolumab was previously approved in Japan. PD-1 inhibitors are also poised to become standard of care treatment for other cancers, including non-small cell lung cancer, renal cell carcinoma and Hodgkin's lymphoma. Immunotherapy using checkpoint inhibition is a different treatment approach to chemotherapy and targeted agents: instead of directly acting on the tumor to induce tumor cell death, checkpoint inhibitors enhance or de novo stimulate antitumor immune responses to eliminate cancer cells. Initial data suggest that objective anti-tumor response rates may be higher with anti-PD-1 agents compared with ipilimumab and the safety profile may be more tolerable. This review explores the development and next steps for PD-1 pathway inhibitors, including discussion of their novel mechanism of action and clinical data to-date, with a focus on melanoma.

Ipilimumab for the treatment of melanoma

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

Validation of a next-generation-sequencing cancer panel for use in the clinical laboratory

CONTEXT

Next-generation sequencing allows for high-throughput processing and sensitive variant detection in multiple genes from small samples. For many diseases, including cancer, a comprehensive mutational profile of a targeted list of genes can be used to simultaneously inform patient care, establish eligibility for ongoing clinical trials, and further research.

OBJECTIVE

To validate a pan-cancer, next-generation-sequencing assay for use in the clinical laboratory.

DESIGN

DNA was extracted from 68 clinical specimens (formalin-fixed, paraffin-embedded; fine-needle aspirates; peripheral blood; or bone marrow) and 5 normal controls. Sixty-four DNA samples (94%; 64 of 68) were successfully processed with the TruSeq Amplicon Cancer Panel (Illumina Inc, San Diego, California) and sequenced in 4 sequencing runs. The data were analyzed at 4 different filter settings for sequencing coverage and variant frequency cutoff.

RESULTS

Libraries created from 40 specimens could be successfully sequenced in a single run and still yield sufficient coverage for robust data analysis of individual samples. Sensitivity for mutation detection down to 5% was demonstrated using dilutions of clinical specimens and control samples. The test was highly repeatable and reproducible and showed 100% concordance with clinically validated Sanger sequencing results. Comparison to an alternate next-generation sequencing technology was performed by also processing 9 of the specimens with the AmpliSeq Cancer Hotspot Panel (version 2; Life Technologies, Grand Island, New York). Thirty of the 31 (97%) TruSeq-detected variants covered by the designs of both panels were confirmed.

CONCLUSIONS

A sensitive, high-throughput, pan-cancer mutation panel for sequencing of cancer hot-spot mutations in 42 genes was validated for routine use in clinical testing.

A LC/MS/MS micro-method for human plasma quantification of vemurafenib. Application to treated melanoma patients

As previously shown for imatinib, therapeutic drug monitoring (TDM) of vemurafenib should be important to measure efficacy of the treatment in melanoma patient. A micro-method based on liquid chromatography coupled to triple quadrupole spectrometry detection using only 10μL of plasma was validated. A simple protein precipitation with water/acetonitrile was used after addition of vemurafenib-(13)C6 as internal standard. The ion transitions used to monitor analytes were m/z 490.2→m/z 255.2 and m/z 383.3 for vemurafenib and m/z 496.2→m/z 261.2 and m/z 389.3 for vemurafenib-(13)C6. Calibration curves were linear in the 0.1-100μg/mL range, the limits of detection and quantification being 0.01μg/mL and 0.1μg/mL, respectively. The intra- and inter-assay precisions evaluated at 0.1, 0.3, 15, 45 and 80μg/mL were lower than 13.3% and the accuracies were in the 93.7-105.8 range. No matrix effect was observed. At steady state, the results of TDM of vemurafenib in 26 patients treated by 960mg twice daily (n=60 samples), 13 patients with 740mg twice daily (n=13) and one with 1200mg twice daily (n=3) showed a great variability of the pharmacokinetics of this compound.

Cutaneous adverse effects of BRAF inhibitors in metastatic malignant melanoma, a prospective study in 20 patients

BACKGROUND

BRAF inhibitors frequently cause significant cutaneous adverse reactions.

OBJECTIVE

To study the timing, prevalence and response to treatment of skin lesions in patients receiving V-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitors.

METHODS

We prospectively studied the cutaneous side-effects of patients with a BRAF mutant (V600E, V600K, V600R) metastatic malignant melanoma treated with a BRAF inhibitor. We systematically registered prevalence, timing of onset and response to treatment.

RESULTS

Twenty patients were treated for 2-52 weeks with a BRAF inhibitor. Eleven patients on vemurafenib (58%) developed cutaneous side-effects and 10 patients (42%) had more than one cutaneous adverse event. Verrucous papillomas were observed in eight patients (42%), after 1-12 weeks. We diagnosed four keratoacanthomas in two patients (11%) after 6-10 weeks and two squamous cell carcinomas in two patients (11%) after 10-16 weeks. Seven patients (37%) developed a hyperkeratotic, folliculocentric eruption after 2-8 weeks, resolving quickly under topical steroids. Four patients (21%) presented a facial erythema, two patients (11%) a seborrhoeic dermatitis-like eczema on the scalp. Three patients (16%) developed cystic lesions after 2-11 weeks. Three patients (16%) presented a hand-foot skin reaction after 4-6 weeks, which was successfully treated with topical steroids and keratolytics. Hyperkeratosis of the nipples was seen in one patient (5%). We observed phototoxic reactions after UV exposure in five patients (26%) and alopecia in two patients (11%) after 8-10 weeks. One patient on dabrafenib developed curly hairs (24 weeks), keratotic papules (1 and 36 weeks), a keratoacanthoma (4 weeks) and a hand-foot skin reaction (31 weeks).

CONCLUSION

Multiple cutaneous toxicities were observed in patients under BRAF inhibitors, mostly well controlled with adequate treatment. We recommend a multidisciplinary approach with regular assessments of the skin by a dermatologist. This allows early identification and adequate treatment to avoid premature discontinuation of a life-prolonging therapy.

Targeting of BRAF resistant melanoma via extracellular matrix metalloproteinase inducer receptor

BACKGROUND

The BRAF inhibitor vemurafenib (PLX) has shown promise in treating metastatic melanoma, but most patients develop resistance to treatment after 6 mo. We identified a transmembrane protein, extracellular matrix metalloproteinase inducer (EMMPRIN) as a cell surface receptor highly expressed by PLX-resistant melanoma. Using an S100A9 ligand, we created an EMMPRIN targeted probe and liposome that binds to melanoma cells in vivo, thus designing a novel drug delivery vehicle.

METHODS

PLX-resistant cells were established through continuous treatment with PLX-4032 over the course of 1 y. Both PLX-resistant and sensitive melanoma cell lines were evaluated for the expression of unique cell surface proteins, which identified EMMPRIN as an overexpressed protein in PLX0-resistant cells and S100A9 is a ligand for EMMPRIN. To design a probe for EMMPRIN, S100A9 ligand was conjugated to a CF-750 near-infrared (NIR) dye. EMMPRIN targeted liposomes were created to encapsulate CF-750 NIR dye. Liposomes were characterized by scanning electron microscopy, flow cytometry, and in vivo analysis. A2058PLX and A2058 cells were subcutaneously injected into athymic mice. S100A9 liposomes were intravenously injected and tumor accumulation was evaluated using NIR fluorescent imaging.

RESULTS

Western blot and flow cytometry demonstrated that PLX sensitive and resistant A2058 and A375 melanoma cells highly express EMMPRIN. S100A9 liposomes were 200 nm diameter and uniformly sized. Flow cytometry demonstrated 100X more intracellular dye uptake by A2058 cells treated with S100A9 liposomes compared with untargeted liposomes. In vivo accumulation of S100A9 liposomes within subcutaneous A2058 and A2058PLX tumors was observed from 6-48 h, with A2058PLX accumulating significantly higher levels (P = 0.001626).

CONCLUSIONS

EMMPRIN-targeted liposomes via an S100A9 ligand are a novel, targeted delivery system which could provide improved EMMPRIN specific drug delivery to a tumor.

Ophthalmic complications of targeted cancer therapy and recently recognized ophthalmic complications of traditional chemotherapy

As our understanding of cancer pathophysiology has increased, so have the number of targeted therapeutic agents available. By targeting specific molecules involved in tumorigenesis, targeted therapeutic agents offer the potential for significant efficacy against tumor cells while minimizing the adverse effects. We highlight the recently recognized ophthalmic complications of targeted cancer therapy, as well as recently recognized complications of traditional chemotherapeutic agents.

Vemurafenib and ipilimumab: new agents for metastatic melanoma

PURPOSE

The development and place in therapy of vemurafenib and ipilimumab for the treatment of metastatic melanoma are reviewed.

SUMMARY

Vemurafenib is an adenosine triphosphate-competitive, reversible, and highly selective BRAF kinase inhibitor targeted at BRAF-V600E and is a first-line option for patients with BRAF-mutation-positive disease. Vemurafenib has clinically significant antitumor activity in metastatic melanoma, and response rates and overall and progression-free survival rates are improved when compared with dacarbazine. Responses also occur quickly, often within days to weeks of starting treatment. Disadvantages of vemurafenib include the short duration of response; significant skin toxicities, including skin cancers and severe photosensitivity; the need for long-term daily administration; and the potential for drug interactions. Ipilimumab is a fully human monoclonal antibody that binds to the cytotoxic T-lymphocyte-associated antigen 4 to enhance and prolong T-cell responses to elicit antitumor activity. Clinical trials have demonstrated the superiority of ipilimumab in terms of overall survival when compared with an immune stimulator and placebo. While the rate of response to ipilimumab is low, responses tended to be more durable than those achieved with vemurafenib. A disadvantage of ipilimumab is that a response may require months, making ipilimumab inappropriate as monotherapy for patients with symptomatic disease. Additional disadvantages are the adverse-effect profile and the requirement of enrollment in the risk evaluation and mitigation strategy program.

CONCLUSION

Vemurafenib and ipilimumab are important advances in the treatment of metastatic melanoma. Benefit is typically short lived for vemurafenib and uncommon for ipilimumab. Neither agent is curative, and clinical trials remain an alternative first-line treatment option.