Randomized phase III study of temozolomide versus dacarbazine in the treatment of patients with advanced metastatic malignant melanoma

Current Treatment of Melanoma Brain Metastasis

OPINION STATEMENT

With greater understanding of underlying biology and development of effective BRAF-targeted therapy and immunotherapy, along with remarkable advances in local treatment such as stereotactic radiosurgery, melanoma brain metastasis (MBM) is witnessing continually improving outcome, with 1-year overall survival rate approaching 85%. Given disease complexity and myriad treatment options, all patients with MBM should ideally be evaluated in a multidisciplinary setting to allow an individualized treatment approach based on prognostic groups, molecular classification, number and size of brain metastasis, and performance status. With improving outcome, pendulum has now swayed to focus more on effective treatment modalities with minimal neurological toxicity while maintaining quality of life. Surgery is usually considered in symptomatic and large MBMs, while stereotactic radiosurgery considered in 1-4 lesions, and now also being explored for up to 15 brain metastases for improved local control. The role of whole brain radiotherapy is diminishing given its neurocognitive toxicities and is reserved for patients with diffuse brain involvement. Cytotoxic chemotherapy has largely been ineffective without evidence for survival benefit. Immune checkpoint inhibitors have become the cornerstone of management for melanoma brain metastasis with durable intracranial tumor control and excellent toxicity profile. For patients with asymptomatic MBMs, ipilimumab and nivolumab have shown intracranial response near 60% and provides comparable clinical benefit in MBMs as for extracranial metastases. For patients with driver BRAF mutation, BRAFi-/MEKi-targeted agents are proven to be effective in MBM with high rate intracranial responses (44-59%). However, the durability of intracranial responses induced by BRAFi/MEKi seems to be shorter than that of extracranial disease. Emerging data support novel combination of systemic therapy and stereotactic radiosurgery, which appears to be safe and effective; however, potential benefits and risks should be evaluated prospectively. Promising ongoing trials will further expand therapeutic evidence in MBM, and patients should be encouraged to participate in clinical trials.

Temozolomide and Pazopanib Combined with FOLFOX Regressed a Primary Colorectal Cancer in a Patient-derived Orthotopic Xenograft Mouse Model

Purpose: The goal of the present study was to determine the efficacy of temozolomide (TEM) and pazopanib (PAZ) combined with FOLFOX (oxaliplatin, leucovorin and 5-fluorouracil) on a colorectal cancer patient-derived orthotopic xenograft (PDOX) mouse model. Materials and Methods: A colorectal cancer tumor from a patient previously established in non-transgenic nude mice was implanted subcutaneously in transgenic green fluorescence protein (GFP)-expressing nude mice in order to label the tumor stromal cells with GFP. Then labeled tumors were orthotopically implanted into the cecum of nude mice. Mice were randomized into four groups: Group 1, untreated control; group 2, TEM + PAZ; group 3, FOLFOX; group 4, TEM + PAZ plus FOLFOX. Tumor width, length, and mouse body weight were measured weekly. The Fluor Vivo imaging System was used to image the GFP-lableled tumor stromal cells in vivo. H&E staining and immunohistochemical staining were used for histological analysis. Results: All three treatments inhibited tumor growth as compared to the untreated control group. The combination of TEM + PAZ + FOLFOX regressed tumor growth significantly more effectively than TEM + PAZ or FOLFOX. Only the combination of TEM + PAZ + FOLFOX group caused a decrease in body weight. PAZ suppressed lymph vessels density in the colorectal cancer PDOX mouse model suggesting inhibition of lymphangiogenesis. Conclusion: Our results suggest that the combination of TEM + PAZ + FOLFOX has clinical potential for colorectal cancer patient.

Survival after checkpoint inhibitors for metastatic acral, mucosal and uveal melanoma

BACKGROUND

Checkpoint inhibitors (CPIs) are thought to be effective against cutaneous melanoma in part because of the large burden of somatic mutations (neoantigens) generated from exposure to ultraviolet radiation. However, rare melanoma subtypes arising from acral skin, mucosal surfaces, and the uveal tract are largely sun-shielded. Genomic studies show these sun-shielded melanomas have a paucity of neoantigens and unique biology; they are thought to be largely resistant to immunotherapy. It has not been definitively shown that CPI improves survival in metastatic sun-shielded melanoma.

METHODS

We reviewed a single institutional experience using antibodies against CTLA-4, PD-1 and/or PD-L1 to treat patients with metastatic melanoma. Primary tumor histology was categorized as cutaneous, unknown, acral, mucosal, or uveal. We studied demographic data, treatment characteristics, and overall survival (OS) after CPI.

RESULTS

We treated 428 patients with metastatic melanoma from 2007 to 2019. Primary tumors were cutaneous in 283 (66%), unknown in 55 (13%), acral in 22 (5%), mucosal in 38 (9%), and uveal in 30 (7%). Patients with metastatic disease from cutaneous primary tumors had median OS after CPI of 45 months compared with 17 months for acral (p=0.047), 18 months for mucosal (p=0.003), and 12 months for uveal (p<0.001). For all patients with sun-shielded melanoma (n=90), first treatment with anti-PD-1 or anti-PD-L1 was followed by a median OS of 9 months compared with 18 months after anti-CTLA-4 (p=0.010) and 20 months after combination therapy (p=0.003). There were 21 patients who achieved actual 3-year survival; 20 received both anti-CTLA-4 and anti-PD-1, either sequentially or in combination. Over 80% of 3-year survivors with progressive disease were treated with local therapy after CPI.

CONCLUSIONS

Long survival in patients with metastatic melanoma from acral, mucosal, and uveal primary tumors was associated with receipt of both anti-CTLA-4 and anti-PD-1 antibodies. Complete responses were rare, and local therapy was frequently employed to control disease progression. While sun-shielded melanomas exhibit worse outcomes after CPI than cutaneous melanomas, with an aggressive multidisciplinary approach, 5-year survival is still possible for 25%-32% of these patients.

Low expression of pro-apoptotic proteins Bax, Bak and Smac indicates prolonged progression-free survival in chemotherapy-treated metastatic melanoma

Despite the introduction of novel targeted therapies, chemotherapy still remains the primary treatment for metastatic melanoma in poorly funded healthcare environments or in case of disease relapse, with no reliable molecular markers for progression-free survival (PFS) available. As chemotherapy primarily eliminates cancer cells by apoptosis, we here evaluated if the expression of key apoptosis regulators (Bax, Bak, Bcl-2, Bcl-xL, Smac, Procaspase-9, Apaf-1, Procaspase-3 and XIAP) allows prognosticating PFS in stage III/IV melanoma patients. Following antibody validation, marker expression was determined by automated and manual scoring of immunohistochemically stained tissue microarrays (TMAs) constructed from treatment-naive metastatic melanoma biopsies. Interestingly and counter-intuitively, low expression of the pro-apoptotic proteins Bax, Bak and Smac indicated better prognosis (log-rank p < 0.0001, p = 0.0301 and p = 0.0227 for automated and p = 0.0422, p = 0.0410 and p = 0.0073 for manual scoring). These findings were independently validated in the cancer genome atlas (TCGA) metastatic melanoma cohort (TCGA-SKCM) at transcript level (log-rank p = 0.0004, p = 0.0104 and p = 0.0377). Taking expression heterogeneity between the markers in individual tumour samples into account allowed defining combinatorial Bax, Bak, Smac signatures that were associated with significantly increased PFS (p = 0.0002 and p = 0.0028 at protein and transcript level, respectively). Furthermore, combined low expression of Bax, Bak and Smac allowed predicting prolonged PFS (> 12 months) on a case-by-case basis (area under the receiver operating characteristic curve (ROC AUC) = 0.79). Taken together, our results therefore suggest that Bax, Bak and Smac jointly define a signature with potential clinical utility in chemotherapy-treated metastatic melanoma.

Immunotherapy for Melanoma

While melanoma is less common than some other skin cancers, it is responsible for nearly 10,000 deaths in the USA each year alone. For many decades, very limited treatment options were available for patients with metastatic melanoma. However, recent breakthroughs have brought new hopes for patients and providers. While targeted therapy with BRAF and MEK inhibitors represents an important cornerstone in the treatment of metastatic melanoma, this chapter carefully reviews the past and current therapy options available, with a significant focus on immunotherapy-based approaches. In addition, we provide an overview of the results of recent advances in the adjuvant setting for patients with resected stage III and stage IV melanoma, as well as in patients with melanoma brain metastases. Finally, we provide a quick overview over the current research efforts in the field of immuno-oncology and melanoma.

European consensus-based interdisciplinary guideline for melanoma. Part 2: Treatment - Update 2019

A unique collaboration of multidisciplinary experts from the European Dermatology Forum, the European Association of Dermato-Oncology and the European Organization for Research and Treatment of Cancer (EORTC) was formed to make recommendations on cutaneous melanoma diagnosis and treatment, based on systematic literature reviews and the experts' experience. Cutaneous melanomas are excised with 1- to 2-cm safety margins. Sentinel lymph node dissection shall be performed as a staging procedure in patients with tumour thickness ≥1.0 mm or ≥0.8 mm with additional histological risk factors, although there is as yet no clear survival benefit for this approach. Therapeutic decisions in stage III/IV patients should be primarily made by an interdisciplinary oncology team ("Tumor Board"). Adjuvant therapies in stage III/IV patients are primarily anti-PD-1, independent of mutational status, or dabrafenib plus trametinib for BRAF-mutant patients. In distant metastasis, either resected or not, systemic treatment is indicated. For first-line treatment, particularly in BRAF wild-type patients, immunotherapy with PD-1 antibodies alone or in combination with CTLA-4 antibodies shall be considered. In particular scenarios for patients with stage IV melanoma and a BRAF-V600 E/K mutation, first-line therapy with BRAF/MEK inhibitors can be offered as an alternative to immunotherapy. In patients with primary resistance to immunotherapy and harbouring a BRAF-V600 E/K mutation, this therapy shall be offered in second-line. Systemic therapy in stage III/IV melanoma is a rapidly changing landscape, and it is likely that these recommendations may change in the near future.

Zinc oxide nanoparticles synthesized from Cardiospermum halicacabum and its anticancer activity in human melanoma cells (A375) through the modulation of apoptosis pathway

Metallic nanoparticles were extensively examined to explore their impending exploitations over pharmaceutical purposes. Current work attempting to explores the cytotoxic capacity of zinc oxide (ZnO) nanoparticles besides to human melanoma cell line (A375). Viability of cells was resoluted, and the promising cytotoxicity potential was exhibited by zinc oxide nanoparticles. Cellular adhesion and morphology was determined by propidium iodide assay. Characterization studies like UV-Spectroscopy, X-ray diffraction (XRD) investigation, transmission electron microscope (TEM), energy dispersive X-ray (EDX) Spec, and Fourier transform infrared (FT-IR) examination confirms the accessibility of measurement, form and volume. The mRNA expression of apoptotic genes like caspase 3, 8 and 9 was elevated followed by the exposure to ZnO nanoparticles and it was narrowly proved that ZnO nanoparticles stimulates the apoptotic cell necrosis at the transcriptional stage. Cardiospermum halicacabum down regulated the apoptotic gene expressions. Reactive oxygen species (ROS) accumulation was augmented at concentration reliant mode, that changed normalize numerous indicator pathways and manipulate the kinetic cellular actions. ZnO nanoparticle synthesized Cardiospermum halicacabum might persuades programmed cell necrosis via elevated ROS levels in cells. CH-ZnONPs was further stimulates the markers of apoptosis and aggravates necrosis of cancerous cells, toxicity to cells, and accretion of ROS. With sourced on above whole data, this might accomplished that CH-ZnONPs amalgamated Cardiospermum halicacabum appreciably possessed a toxicity to human melanoma cells (A375) via provoking the apoptotic cell necrosis, entailed feasible efficacy of CH-ZnONPs besides malignancy management.

Novel Immunotherapy Combinations

PURPOSE OF REVIEW

The last decade witnessed an explosion in immunotherapeutic agent approvals for various malignancies. The success of immune checkpoint inhibitors (CTLA-4 and PD-1/PD-L1) in melanoma quickly sprung to other cancer types and are considered the emerging face of oncology.

RECENT FINDINGS

Antibodies to CTLA-4 were first to enter the field, quickly followed by PD-1/PD-L1 inhibitors. Combination anti-CTLA4 and anti-PD-1/PD-L1 therapies were investigated, and after demonstrating improved responses, rapidly gained approval. Certain tumor types previously considered non-immunogenic also demonstrated durable responses which has been a remarkable discovery. However, not all tumor types respond to immunotherapies and it is widely recognized that tumor-specific immune inflammatory status predicts the best responders. Ongoing translational work indicates specific upregulation in additional immune checkpoints that circumvent response to anti-CTLA4 and anti-PD-1/PD-L1 antibodies. Here, we provide a comprehensive review of promising therapies on the horizon with unique combinations designed to overcome resistance or expand the pool of treatment responders.

Principles of Immunotherapy in Melanoma

Advanced/metastatic melanoma is an aggressive cancer with a low survival rate. Traditional cytotoxic chemotherapies do not appreciably extend life and systemic cytokine/chemokine administration produces toxic side effects. By harnessing the surveillance and cytotoxic features of the immune system, immunotherapies can provide a durable response and are proved to improve disease outcomes in patients with advanced/metastatic melanoma and other cancers. Close monitoring is necessary, however, to identify and treat immune system-related adverse events before they become life-threatening. Because metastatic lesions can respond differently to immunotherapies, modified response criteria have been developed to assist physicians in tracking patient response to treatment.

Acute kidney injury from immune checkpoint inhibitor use

Immune checkpoint inhibitors are novel oncological medications, current classes of which include monoclonal antibodies that target inhibitory receptors cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), programmed death 1 protein (PD-1) and programmed death-ligand 1. While they are novel in their ability to treat cancer, they also have a unique spectrum of immune-related adverse events. Renal-related immune adverse events, though rare, are an increasingly recognised clinical entity. We present the case of a 67-year-old man with acute kidney injury (AKI) after the second cycle of combination anti-CTLA-4 and anti-PD-1 antibodies for metastatic cutaneous melanoma. He presented with vomiting and diarrhoea, and AKI secondary to dehydration was treated with aggressive rehydration. After failing to recover biochemically, a renal biopsy was performed, which demonstrated severe acute interstitial nephritis. The culprit medications were held and he was treated with steroids. With immunosuppression, creatinine improved to pretreatment values.

The Melding of Drug Screening Platforms for Melanoma

The global incidence of cancer is rising rapidly and continues to be one of the leading causes of death in the world. Melanoma deserves special attention since it represents one of the fastest growing types of cancer, with advanced metastatic forms presenting high mortality rates due to the development of drug resistance. The aim of this review is to evaluate how the screening of drugs and compounds for melanoma has been performed over the last seven decades. Thus, we performed literature searches to identify melanoma drug screening methods commonly used by research groups during this timeframe. In vitro and in vivo tests are essential for the development of new drugs; however, incorporation of in silico analyses increases the possibility of finding more suitable candidates for subsequent tests. In silico techniques, such as molecular docking, represent an important and necessary first step in the screening process. However, these techniques have not been widely used by research groups to date. Our research has shown that the vast majority of research groups still perform in vitro and in vivo tests, with emphasis on the use of in vitro enzymatic tests on melanoma cell lines such as SKMEL and in vivo tests using the B16 mouse model. We believe that the union of these three approaches (in silico, in vitro, and in vivo) is essential for improving the discovery and development of new molecules with potential antimelanoma action. This workflow would provide greater confidence and safety for preclinical trials, which will translate to more successful clinical trials and improve the translatability of new melanoma treatments into clinical practice while minimizing the unnecessary use of laboratory animals under the principles of the 3R's.

Frugoside Induces Mitochondria-Mediated Apoptotic Cell Death through Inhibition of Sulfiredoxin Expression in Melanoma Cells

Malignant melanoma is the most life-threatening neoplasm of the skin. Despite the increase in incidence, melanoma is becoming more resistant to current therapeutic agents. The bioactive compound frugoside has been recently reported to inhibit growth when used in various cancer cells. However, this effect has not been demonstrated in melanoma. Here, we found that frugoside inhibited the rate of reduction of hyperoxidized peroxiredoxins (Prxs) by downregulating sulfiredoxin (Srx) expression. Furthermore, frugoside increased the accumulation of sulfinic Prxs and reactive oxygen species (ROS) and stimulated p-p38 activation, resulting in the mitochondria-mediated death of M14 and A375 human melanoma cells. The mitochondria-mediated cell death induced by frugoside was inhibited by the overexpression of Srx and antioxidants, such as N-acetyl cysteine and diphenyleneiodonium. In addition, we observed that frugoside inhibited tumor growth without toxicity through a M14 xenograft animal model. Taken together, our findings reveal that frugoside exhibits a novel antitumor effect based on a ROS-mediated cell death in melanoma cells, which may have therapeutic implications.

Enhanced emergence of antibiotic-resistant pathogenic bacteria after in vitro induction with cancer chemotherapy drugs

BACKGROUND

Infections with antibiotic-resistant pathogens in cancer patients are a leading cause of mortality. Cancer patients are treated with compounds that can damage bacterial DNA, potentially triggering the SOS response, which in turn enhances the bacterial mutation rate. Antibiotic resistance readily occurs after mutation of bacterial core genes. Thus, we tested whether cancer chemotherapy drugs enhance the emergence of resistant mutants in commensal bacteria.

METHODS

Induction of the SOS response was tested after the incubation of Escherichia coli biosensors with 39 chemotherapeutic drugs at therapeutic concentrations. The mutation frequency was assessed after induction with the SOS-inducing chemotherapeutic drugs. We then tested the ability of the three most highly inducing drugs to drive the emergence of resistant mutants of major bacterial pathogens to first-line antibiotics.

RESULTS

Ten chemotherapeutic drugs activated the SOS response. Among them, eight accelerated the evolution of the major commensal E. coli, mostly through activation of the SOS response, with dacarbazine, azacitidine and streptozotocin enhancing the mutation rate 21.3-fold (P < 0.001), 101.7-fold (P = 0.01) and 1158.7-fold (P = 0.02), respectively. These three compounds also spurred the emergence of imipenem-resistant Pseudomonas aeruginosa (up to 6.21-fold; P = 0.05), ciprofloxacin-resistant Staphylococcus aureus (up to 57.72-fold; P = 0.016) and cefotaxime-resistant Enterobacteria cloacae (up to 4.57-fold; P = 0.018).

CONCLUSIONS

Our results suggest that chemotherapy could accelerate evolution of the microbiota and drive the emergence of antibiotic-resistant mutants from bacterial commensals in patients. This reveals an additional level of complexity of the interactions between cancer, chemotherapy and the gut microbiota.

The Use of Anti-CD40 mAb in Cancer

Immunomodulatory monoclonal antibody (mAb) therapy is at the forefront of developing cancer therapeutics with numerous targeted agents proving highly effective in selective patients at stimulating protective host immunity, capable of eradicating established tumours and leading to long-term disease-free states. The cell surface marker CD40 is expressed on a range of immune cells and transformed cells in malignant states whose signalling plays a critical role in modulating adaptive immune responses. Anti-CD40 mAb therapy acts via multiple mechanisms to stimulate anti-tumour immunity across a broad range of lymphoid and solid malignancies. A wealth of preclinical research in this field has led to the successful development of multiple anti-CD40 mAb agents that have shown promise in early-phase clinical trials. Significant progress has been made to enhance the engagement of antibodies with immune effectors through their interactions with Fcγ receptors (FcγRs) by the process of Fc engineering. As more is understood about how to best optimise these agents, principally through the fine-tuning of mAb structure and choice of synergistic partnerships, our ability to generate robust, clinically beneficial anti-tumour activity will form the foundation for the next generation of cancer therapeutics.

Management of metastatic cutaneous melanoma: updates in clinical practice

In recent years, several drugs have been approved for the treatment of patients with metastatic cutaneous melanoma, completely reshaping the landscape of this aggressive disease. Immune therapy with cytotoxic T-lymphocyte antigen 4 and programmed cell death-1 inhibitors yielded significant and durable responses, achieving long-term disease control in up to 40% of the patients. BRAF inhibitors (BRAFi), in combination with MEK inhibitors, also resulted in improved overall survival compared with single-agent BRAFi in patients with BRAFV600-mutated metastatic melanoma. The optimized sequencing and duration of treatment, however, is yet to be found. In this article, we thoroughly review current data and discuss how to best sequence the various treatment modalities available at present, based on four distinct clinical presentations commonly seen in clinic. In addition, we review treatment options beyond checkpoint inhibitors and targeted therapy, which may be required by patients failing such effective treatments.

Endobronchial, laryngeal and mediastinal melanoma: a rare constellation of metastatic disease

A 45-year-old man presents with acute respiratory failure. Imaging revealed a left mainstem endobronchial mass with subcarinal lymphadenopathy, but no other evidence of a primary tumour. An incidental laryngeal nodule was found during bronchoscopy. Biopsies of this lesion by nasopharyngoscopy and subcarinal lymph nodes via mediastinoscopy were performed. Histopathological and immunohistochemical examination showed evidence of melanoma in both samples. Mutational analysis identified the presence of a BRAFV600E mutation. The patient underwent bronchoscopic ablation of the left mainstem endobronchial tumour with laser therapy followed by initiation of encorafenib and binimetinib combination therapy. The patient remains alive at 4 months after initial presentation of disease. This case adds to the body of literature highlighting the clinical heterogeneity and challenges of the management of metastatic pulmonary melanoma. To the best of our knowledge, this simultaneous constellation of metastasis has not been described before.

Using a Benefit-Risk Analysis Approach to Capture Regulatory Decision Making: Melanoma

Drug regulators seek to make decisions regarding drug approvals based on analysis of the relevant benefits and risks. In this work, 25 US Food and Drug Administration (FDA) decisions on melanoma drugs were identified and analyzed based on clinical trial results published between 1999 and 2017. In each case, the benefits and risks of the new drug in each clinical trial relative to a comparator (typically the control arm of the same clinical trial) were quantified. The benefits and risks were analyzed using a common scale to allow for direct comparison. A sensitivity analysis was conducted using vemurafenib to explore the magnitude of uncertainty in the quantitative assessments. The associated FDA decision outcomes of the new drugs were consistent with the benefits and risks quantified in this work.

DNA repair in personalized brain cancer therapy with temozolomide and nitrosoureas

Alkylating agents have been used since the 60ties in brain cancer chemotherapy. Their target is the DNA and, although the DNA of normal and cancer cells is damaged unselectively, they exert tumor-specific killing effects because of downregulation of some DNA repair activities in cancer cells. Agents exhibiting methylating properties (temozolomide, procarbazine, dacarbazine, streptozotocine) induce at least 12 different DNA lesions. These are repaired by damage reversal mechanisms involving the alkyltransferase MGMT and the alkB homologous protein ALKBH2, and through base excision repair (BER). There is a strong correlation between the MGMT expression level and therapeutic response in high-grade malignant glioma, supporting the notion that O⁶-methylguanine and, for nitrosoureas, O⁶-chloroethylguanine are the most relevant toxic damages at therapeutically relevant doses. Since MGMT has a significant impact on the outcome of anti-cancer therapy, it is a predictive marker of the effectiveness of methylating anticancer drugs, and clinical trials are underway aimed at assessing the influence of MGMT inhibition on the therapeutic success. Other DNA repair factors involved in methylating drug resistance are mismatch repair, DNA double-strand break (DSB) repair by homologous recombination (HR) and DSB signaling. Base excision repair and ALKBH2 might also contribute to alkylating drug resistance and their downregulation may have an impact on drug sensitivity notably in cells expressing a high amount of MGMT and at high doses of temozolomide, but the importance in a therapeutic setting remains to be shown. MGMT is frequently downregulated in cancer cells (up to 40% in glioblastomas), which is due to CpG promoter methylation. Astrocytoma (grade III) are frequently mutated in isocitrate dehydrogenase (IDH1). These tumors show a surprisingly good therapeutic response. IDH1 mutation has an impact on ALKBH2 activity thus influencing DNA repair. A master switch between survival and death is p53, which often retains transactivation activity (wildtype) in malignant glioma. The role of p53 in regulating survival via DNA repair and the routes of death are discussed and conclusions as to cancer therapeutic options were drawn.

Antiproliferative and apoptotic effects of caffeic acid on SK-Mel-28 human melanoma cancer cells

Cutaneous melanoma (CM) is an extremely aggressive cancer presenting low survival and high mortality. The vast majority of patients affected by this disease does not respond or show resistance to the chemotherapeutic drugs, which makes the treatment ineffective. In this sense, the necessity for the development of new agents to assist in CM therapy is extremely important. One of the sources of great interest in this search are compounds of natural origin. Among these compounds, caffeic acid has demonstrated a broad spectrum of pharmacological activities as well as antitumor effects in some types of cancer. Therefore, the objective of this work was to investigate the possible antitumor effect of caffeic acid on the SK-Mel-28 cell line, human CM cells. Cells were cultured in flasks with culture medium containing fetal bovine serum, antibiotic, and antifungal, and maintained in ideal conditions. Cells were treated with 25 µM, 50 µM, 100 µM, 150 µM and 200 µM of caffeic acid and dacarbazine at 1 mg/mL. We verified the effect on cell viability and cell death, apoptosis, cell cycle, colony formation and gene expression of caspases. Results showed a decrease in cell viability, cell death induction by apoptosis, inhibition of colony formation, modulation of cell cycle and alterations in gene expression of caspases after caffeic acid treatment. These results suggest an antitumor effect of the compound on SK-Mel-28 cells. This study provides original information on mechanisms by which caffeic acid may play a key role in preventing tumor progression in human melanoma cells.

Bee Venom and Its Peptide Component Melittin Suppress Growth and Migration of Melanoma Cells via Inhibition of PI3K/AKT/mTOR and MAPK Pathways

Malignant melanoma is the deadliest form of skin cancer and highly chemoresistant. Melittin, an amphiphilic peptide containing 26 amino acid residues, is the major active ingredient from bee venom (BV). Although melittin is known to have several biological activities such as anti-inflammatory, antibacterial and anticancer effects, its antimelanoma effect and underlying molecular mechanism have not been fully elucidated. In the current study, we investigated the inhibitory effect and action mechanism of BV and melittin against various melanoma cells including B16F10, A375SM and SK-MEL-28. BV and melittin potently suppressed the growth, clonogenic survival, migration and invasion of melanoma cells. They also reduced the melanin formation in α-melanocyte-stimulating hormone (MSH)-stimulated melanoma cells. Furthermore, BV and melittin induced the apoptosis of melanoma cells by enhancing the activities of caspase-3 and -9. In addition, we demonstrated that the antimelanoma effect of BV and melittin is associated with the downregulation of PI3K/AKT/mTOR and MAPK signaling pathways. We also found that the combination of melittin with the chemotherapeutic agent temozolomide (TMZ) significantly increases the inhibition of growth as well as invasion in melanoma cells compared to melittin or TMZ alone. Taken together, these results suggest that melittin could be potentially applied for the prevention and treatment of malignant melanoma.

[Melanoma update]

Incidence of malignant melanoma has been increasing since the 1980s. For loco-regional stages, surgery is still the best treatment. Melanoma has a high distant metastatic potential and prognosis of advanced stages was until recently very poor. Since 2011 however, a real revolution has taken place in the treatment of metastatic melanoma. This is based upon considerably improved knowledge of the molecular mechanisms of melanoma and cancer immunology. Thus, two new classes of systemic therapeutic agents are now available: immunotherapies (immunological checkpoint inhibitors), which increase the antitumor immune response, and targeted therapies (BRAF and MEK inhibitors) for patients with BRAF V600-mutant melanoma. Overall survival is now 2 years or above, with hope for a cure in some cases. Unfortunately, the efficacy of these treatments is incomplete and many studies are underway to try to identify predictive biomarkers, and multiple combinations are being evaluated to increase response rates. The efficacy of these treatments has also been shown in the adjuvant setting in high-risk melanoma, they should be available shortly.

Melanom

Das Melanom ist der gefährlichste Hautkrebs mit der höchsten Sterblichkeitsrate, der schon bei jungen Menschen auftreten kann und seit Jahrzehnten steigende Inzidenz verzeichnet (Jemal et al. 2007; Little et al. 2012). Jährlich erkranken weltweit etwa 137.000 Menschen am Melanom und 37.000 versterben an der Erkrankung (Boyle et al. 2004). Die Inzidenz liegt weltweit jährlich bei 2,3–2,6/100.000 Einwohner (Pisani et al. 2002). In Deutschland beträgt die Inzidenz 19,2/100.000 Einwohner und es verstarben 2711 Betroffene im Jahre 2010 (Statistisches Bundesamt).

Immune checkpoint blockade and its combination therapy with small-molecule inhibitors for cancer treatment

Initially understood for its physiological maintenance of self-tolerance, the immune checkpoint molecule has recently been recognized as a promising anti-cancer target. There has been considerable interest in the biology and the action mechanism of the immune checkpoint therapy, and their incorporation with other therapeutic regimens. Recently the small-molecule inhibitor (SMI) has been identified as an attractive combination partner for immune checkpoint inhibitors (ICIs) and is becoming a novel direction for the field of combination drug design. In this review, we provide a systematic discussion of the biology and function of major immune checkpoint molecules, and their interactions with corresponding targeting agents. With both preclinical studies and clinical trials, we especially highlight the ICI + SMI combination, with its recent advances as well as its application challenges.

Clinical and economic outcomes associated with treatment sequences in patients with BRAF-mutant advanced melanoma

AIM

The cost-effectiveness of treatment sequences in BRAF-mutant advanced melanoma.

MATERIALS & METHODS

A discrete event simulation model was developed to estimate total costs and health outcomes over a patient's lifetime (30 years). Efficacy was based on the CheckMate 067/069 trials and a matching-adjusted-indirect comparison between immuno-oncology and targeted therapies. Safety, cost (in US dollars; US third-party payer perspective) and health-related quality-of-life inputs were based on published literature.

RESULTS

Estimated survival gain was higher for sequences initiating with anti-PD-1 + anti-CTLA-4 than for anti-PD-1 monotherapy or BRAF+MEK inhibitors. The incremental cost-effectiveness ratio per QALY gained for first-line anti-PD-1 + anti-CTLA-4 was US$54,273 versus first-line anti-PD-1 and $79,124 versus first-line BRAF+MEK inhibitors.

CONCLUSION

Initiating treatment with anti-PD-1 + anti-CTLA-4 was more cost-effective than initiation with anti-PD-1 monotherapy or BRAF+MEK inhibitors.

Indications for the surgical resection of stage IV disease

Tumor biology and careful patient selection weigh heavily in determining the appropriate role of surgical resection in stage IV melanoma. Historically, surgical resection for highly selected patients with metastatic melanoma was the only treatment modality associated with improved long-term survival and the ability to provide palliation. With the new age of effective systemic therapies, the treatment of metastatic melanoma has become more intricate and future work is needed to better define the role for surgery within the current treatment paradigm.

Evaluating Progression-Free Survival as a Surrogate Outcome for Health-Related Quality of Life in Oncology: A Systematic Review and Quantitative Analysis

IMPORTANCE

Progression-free survival (PFS) has become a commonly used outcome to assess the efficacy of new cancer drugs. However, it is not clear if delay in progression leads to improved quality of life with or without overall survival benefit.

OBJECTIVE

To evaluate the association between PFS and health-related quality of life (HRQoL) in oncology through a systematic review and quantitative analysis of published randomized clinical trials. Eligible trials addressed oral, intravenous, intraperitoneal, or intrapleural chemotherapy or biological treatments, and reported PFS or health-related quality of life.

DATA SOURCES

For this systematic review and quantitative analysis of randomized clinical trials of patients with cancer, we searched Medline, Embase, and the Cochrane Central Register of Controlled Trials from January 1, 2000, through May 4, 2016.

STUDY SELECTION

Paired reviewers independently screened citations, extracted data, and assessed risk of bias of included studies.

DATA EXTRACTION AND SYNTHESIS

We examined the association of difference in median PFS duration (in months) between treatment groups with difference in global, physical, and emotional HRQoL scores between groups (standardized to a range of 0-100, with higher scores representing better HRQoL) using weighted simple regressions.

MAIN OUTCOME AND MEASURE

The association between PFS duration and HRQoL.

RESULTS

Of 35 960 records screened, 52 articles reporting on 38 randomized clinical trials involving 13 979 patients across 12 cancer types using 6 different HRQoL instruments were included. The mean (SD) difference in median PFS between the intervention and the control arms was 1.91 (3.35) months. The mean (SD) differences in change of HRQoL adjusted to per-month values were -0.39 (3.59) for the global domain, 0.26 (5.56) for the physical domain, and 1.08 (3.49) for the emotional domain. The slope of the association between the difference in median PFS and the difference in change for global HRQoL (n = 30 trials) was 0.12 (95% CI, -0.27 to 0.52); for physical HRQoL (n = 20 trials) it was -0.20 (95% CI, -0.62 to 0.23); and for emotional HRQoL (n = 13 trials) it was 0.78 (95% CI, -0.05 to 1.60).

CONCLUSIONS AND RELEVANCE

We failed to find a significant association between PFS and HRQoL in cancer clinical trials. These findings raise questions regarding the assumption that interventions prolonging PFS also improve HRQoL in patients with cancer. Therefore, to ensure that patients are truly obtaining important benefit from cancer therapies, clinical trial investigators should measure HRQoL directly and accurately, ensuring adequate duration and follow-up.

Indoleamine 2,3-Dioxygenase (IDO) Inhibition as a Strategy to Augment Cancer Immunotherapy

Indoleamine 2,3-dioxygenase (IDO) is an enzyme of interest in immuno-oncology because of the immunosuppressive effects that result from its role in tryptophan catabolism. IDO is upregulated in malignancy and is associated with poor prognosis in multiple cancer types. IDO inhibitors have been developed to target IDO, both directly and indirectly. Pre-clinical data have shown combined IDO and checkpoint inhibition to be an efficacious strategy for tumor control. Clinical trials of IDO inhibitors with chemotherapy or immunotherapy are currently underway. This review describes the function of IDO and its inhibitors and summarizes the efficacy and toxicity data from recent clinical trials with these drugs.

Update of survival and cost of metastatic melanoma with new drugs: Estimations from the MelBase cohort

PURPOSE

Since 2011, significant progress was observed in metastatic melanoma (MM), with the commercialisation of seven immunotherapies or targeted therapies, which showed significant improvement in survival. In France, in 2004, the cost of MM was estimated at €1634 per patient; this cost has not been re-estimated since. This study provided an update on survival and cost in real-life clinical practice.

METHODS

Clinical and economic data (treatments, hospitalisations, radiotherapy sessions, visits, imaging and biological exams) were extracted from the prospective MelBase cohort, collecting individual data in 955 patients in 26 hospitals, from diagnosis of metastatic disease until death. Survival was estimated by the Kaplan-Meier method. Costs were calculated from the health insurance perspective using French tariffs. For live patients, survival and costs were extrapolated using a multistate model, describing the 5-year course of the disease according to patient prognostic factors and number of treatment lines.

RESULTS

Since the availability of new drugs, the mean survival time of MM patients has increased to 23.6 months (_95%confidence interval [CI] :21.2;26.6), with 58% of patients receiving a second line of treatment. Mean management costs increased to €269,682 (_95%CI:244,196;304,916) per patient. Drugs accounted for 80% of the total cost.

CONCLUSION

This study is the first that evaluated the impact of immunotherapies and targeted therapies both on survival and cost in real-life conditions. Alongside the introduction of breakthrough therapies in the first and subsequent lines, MM has been associated with a significant increase in survival but also in costs, raising the question of financial sustainability.

Reversing effect of Lupeol on vasculogenic mimicry in murine melanoma progression

Vasculogenic mimicry, an endothelia-independent tumor microcirculation has been found in various cancers and is thought to be achieved by cancer stem like cells. Dacarbazine resistance is one of the most common features of melanoma and recent studies suggest that the mode of resistance is closely related to the formation of vasculogenic mimicry. In our work, we examined the anticancer effect of Lupeol, a novel phytochemical with Dacarbazine in vivo and in vitro. Results demonstrated adequate cytotoxicity followed by down regulation of CD 133 expression in Lupeol treated B16-F10 cell line. In solid tumor model the drug also inhibited vasculogenic mimicry along with angiogenesis by altering both the cancer stem cell as well as the endothelial progenitor cell population. Lupeol hindered the maturation of bone marrow derived endothelial progenitors and thus, retarded the formation of rudimentary tumor microvessels. Notably, Dacarbazine treatment demonstrated unresponsiveness to B16-F10 cells in both in vivo and in vitro model via upregulation of CD 133 expression and increased formation of vasculogenic mimicry tubes. Together, these data indicate that Lupeol alone can become a proficient agent in treating melanoma, inhibiting vasculogenic mimicry and might play a significant role in subduing Dacarbazine induced drug resistance.

Autophagy modulates temozolomide-induced cell death in alveolar Rhabdomyosarcoma cells

Rhabdomyosarcoma (RMS) is a muscle-derived tumor. In both pre-clinical and clinical studies Temozolomide (TMZ) has been recently tested against RMS; however, the precise mechanism of action of TMZ in RMS remains unclear. Here we demonstrate that TMZ decreases the cell viability of the RH30 RMS and C2C12 cell line, where cells display evidence of mitochondrial outer membrane permeability. Interestingly, the C2C12 mouse myoblast line was relatively more resistant to TMZ-induced apoptosis. Moreover, we observed that TMZ activated biochemical and morphological markers of autophagy in both cell lines. Autophagy inhibition in both RH30 and C2C12 cells significantly increased TMZ-induced cell death. In RH30 cells, TMZ increased Mcl-1 and Bax protein expression compared to corresponding time match controls while in C2C12 Mcl-1, Bcl-2, Bcl-XL, and Bax protein expression were not changed. Baf-A1 co-treatment with TMZ significantly decrease Mcl-1 expression compared to TMZ while increase Bax expression in C2C12 cells (Bcl2 and Bcl-XL do not significantly change in Baf-A1/TMZ co-treatment). Using a three-dimensional (3D) C2C12 and RH30 culture model we demonstrated that TMZ is significantly more toxic in RH30 cells (live/dead assay). Additionally, we have observed in our 3D culture model that TMZ induced both apoptosis (cleavage of PARP) and autophagy (LC3-puncta and localization of LC3/p62). Therefore, our data demonstrate that TMZ induces simultaneous autophagy and apoptosis in both RH30 and C2C12 cells in 2D and 3D culture model, where RH30 cells are more sensitive to TMZ-induced death. Furthermore, autophagy serves to protect RH30 cells from TMZ-induced death.

Mechanisms of resistance to BRAF and MEK inhibitors and clinical update of US Food and Drug Administration-approved targeted therapy in advanced melanoma

Approximately 50% of melanomas harbor an activating BRAF mutation. Combined BRAF and MEK inhibitors such as dabrafenib and trametinib, vemurafenib and cobimetinib, and encorafenib and binimetinib are US Food and Drug Administration (FDA)-approved to treat patients with BRAF^V600-mutated advanced melanoma. Both genetic and epigenetic alterations play a major role in resistance to BRAF inhibitors by reactivation of the MAPK and/or the PI3K–Akt pathways. The role of BRAF inhibitors in modulating the immunomicroenvironment and perhaps enhancing the efficacy of checkpoint inhibitors is gaining interest. This article provides a comprehensive review of mechanisms of resistance to BRAF and MEK inhibitors in melanoma and summarizes landmark trials that led to the FDA approval of BRAF and MEK inhibitors in metastatic melanoma.

Spatially Resolved Transcriptomics Enables Dissection of Genetic Heterogeneity in Stage III Cutaneous Malignant Melanoma

Cutaneous malignant melanoma (melanoma) is characterized by a high mutational load, extensive intertumoral and intratumoral genetic heterogeneity, and complex tumor microenvironment (TME) interactions. Further insights into the mechanisms underlying melanoma are crucial for understanding tumor progression and responses to treatment. Here we adapted the technology of spatial transcriptomics (ST) to melanoma lymph node biopsies and successfully sequenced the transcriptomes of over 2,200 tissue domains. Deconvolution combined with traditional approaches for dimensional reduction of transcriptome-wide data enabled us to both visualize the transcriptional landscape within the tissue and identify gene expression profiles linked to specific histologic entities. Our unsupervised analysis revealed a complex spatial intratumoral composition of melanoma metastases that was not evident through morphologic annotation. Each biopsy showed distinct gene expression profiles and included examples of the coexistence of multiple melanoma signatures within a single tumor region as well as shared profiles for lymphoid tissue characterized according to their spatial location and gene expression profiles. The lymphoid area in close proximity to the tumor region displayed a specific expression pattern, which may reflect the TME, a key component to fully understanding tumor progression. In conclusion, using the ST technology to generate gene expression profiles reveals a detailed landscape of melanoma metastases. This should inspire researchers to integrate spatial information into analyses aiming to identify the factors underlying tumor progression and therapy outcome.Significance: Applying ST technology to gene expression profiling in melanoma lymph node metastases reveals a complex transcriptional landscape in a spatial context, which is essential for understanding the multiple components of tumor progression and therapy outcome. Cancer Res; 78(20); 5970-9. ©2018 AACR.

Molecular analysis of the dual targeting of the epidermal growth factor receptor and the O6-methylguanine-DNA methyltransferase with a double arm hybrid molecule

Disordered expression of the epidermal growth factor receptor (EGFR) has been associated with induction of DNA repair genes (e.g. XRCC1, ERCC1) and resistance to radiation and genotoxic drugs. However, our previous work showed that EGFR inhibition did not affect O⁶-methylguanine-DNA methyltransferase (MGMT)-mediated resistance. In order to block uncoupled events associated with EGFR and MGMT, we designed MR30, a single molecule termed “combi-molecule” that contains a quinazoline arm targeted to EGFR and an O⁶-benzylguanine (O⁶-BG) moiety to block MGMT. Molecular analysis of the mechanism of action of its two arms showed that: (a) it could block EGFR phosphorylation, (b) down-regulate the RAF-MAPK and the PI3K-AKT pathways, and (c) covalently modify MGMT through S-benzylation, as confirmed by MALDI analysis of a direct binding assay with isolated MGMT, (d) it induced a dose-dependent down-regulation of MGMT in lung and melanoma cells. The pleiotropic mechanism of action of MR30 culminated into strong growth inhibition (IC₅₀: 0.018-6.02 μM), with superior activity when compared with an equimolar combination of gefitinib (a clinical EGFR inhibitor) and O⁶-BG (a known MGMT inhibitor). Pulse exposure experiments were required to attenuate the contribution of EGFR inhibition to the strong potency of MR30, thereby allowing to achieve the dose level required to sensitize cells to temozolomide (TMZ). Indeed, MR30 significantly sensitized EGFR-MGMT co-expressing cells to TMZ (p<0.05-0.0001). The results in toto suggest that MR30 is the first prototype of agents that may be used against tumours addicted to EGFR and to sensitize resistant tumours co-expressing EGFR and MGMT to TMZ.

Rare Stochastic Expression of O6-Methylguanine- DNA Methyltransferase (MGMT) in MGMT-Negative Melanoma Cells Determines Immediate Emergence of Drug-Resistant Populations upon Treatment with Temozolomide In Vitro and In Vivo

The chemotherapeutic agent temozolomide (TMZ) kills tumor cells preferentially via alkylation of the O6-position of guanine. However, cells that express the DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT), or harbor deficient DNA mismatch repair (MMR) function, are profoundly resistant to this drug. TMZ is in clinical use for melanoma, but objective response rates are low, even when TMZ is combined with O6-benzylguanine (O6BG), a potent MGMT inhibitor. We used in vitro and in vivo models of melanoma to characterize the early events leading to cellular TMZ resistance. Melanoma cell lines were exposed to a single treatment with TMZ, at physiologically relevant concentrations, in the absence or presence of O6BG. Surviving clones and mass cultures were analyzed by Western blot, colony formation assays, and DNA methylation studies. Mice with melanoma xenografts received TMZ treatment, and tumor tissue was analyzed by immunohistochemistry. We found that MGMT-negative melanoma cell cultures, before any drug treatment, already harbored a small fraction of MGMT-positive cells, which survived TMZ treatment and promptly became the dominant cell type within the surviving population. The MGMT-negative status in individual cells was not stable, as clonal selection of MGMT-negative cells again resulted in a mixed population harboring MGMT-positive, TMZ-resistant cells. Blocking the survival advantage of MGMT via the addition of O6BG still resulted in surviving clones, although at much lower frequency and independent of MGMT, and the resistance mechanism of these clones was based on a common lack of expression of MSH6, a key MMR enzyme. TMZ treatment of mice implanted with MGMT-negative melanoma cells resulted in effective tumor growth delay, but eventually tumor growth resumed, with tumor tissue having become MGMT positive. Altogether, these data reveal stochastic expression of MGMT as a pre-existing, key determinant of TMZ resistance in melanoma cell lines. Although MGMT activity can effectively be eliminated by pharmacologic intervention with O6BG, additional layers of TMZ resistance, although considerably rarer, are present as well and minimize the cytotoxic impact of TMZ/O6BG combination treatment. Our results provide rational explanations regarding clinical observations, where the TMZ/O6BG regimen has yielded mostly disappointing outcomes in melanoma patients.

PAXX Participates in Base Excision Repair via Interacting with Pol β and Contributes to TMZ Resistance in Glioma Cells

Non-homologous end joining (NHEJ) is one of the major DNA repair pathway in mammalian cell that can ligate a variety of DNA ends. However, how does all NHEJ factors communicate and organize together to achieve the final repair is still not clear. PAralog of XRCC4 and XLF (PAXX) was a new factor identified recently that play an important role in NHEJ. PAXX contributes to efficient NHEJ by interacting with Ku, which is a NHEJ key factor, and PAXX deficiency cause sensitivity to DNA double-strand break repair (DSBR). We observed that PAXX-deficient cells showed slight increase of homologous recombination (HR, which is another major DSBR repair pathways in mammalian cells). More importantly, we found that PAXX contributes to base excision repair pathway via interaction of polymerase beta (pol β). Temozolomide (TMZ) is one of the standard chemotherapies widely applied in glioblastoma. However, TMZ resistance and lack of potent chemotherapy agents can substitute TMZ. We observed that PAXX deficiency cause more sensitivity to TMZ-resistant glioma cells. In conclusion, the PAXX contributes to a variety of DNA repair pathways and TMZ resistance. Therefore, inhibition of PAXX may provide a promising way to overcome TMZ resistance and improve TMZ therapeutic effects in glioma treatment.

The impact of effective systemic therapies on surgery for stage IV melanoma

INTRODUCTION

The outcomes of patients with metastatic melanoma have significantly improved with the introduction of effective systemic therapies (ESTs). The role of surgery in the context of ESTs for stage IV melanoma is evolving. We sought to characterise the changing patterns of surgery and oncological outcomes in patients with stage IV melanoma treated before and after the establishment of ESTs.

METHODS

Patients undergoing surgical resection of stage IV melanoma were identified from our institutional database from 2003 to 2015. Patients were grouped into two cohorts, those referred before EST (2003-2007) and after EST (2011-2015). Clinicopathological variables, patterns of surgery and oncological outcomes in the two groups were compared.

RESULTS

A total of 138 patients underwent surgery for stage IV melanoma (n = 69 in each cohort). We observed no significant difference in the ratio of operations/patients performed. However, the pattern of operations altered, with a significant decrease in in-transit excisions (0.9% vs. 19.4%, p < 0.001) and an increase in abdominal metastasectomies (21.1% vs. 4.2%, p < 0.001), in the after-EST cohort. Novel indications for surgical intervention were noted in the after-EST cohort, with a significant increase in potentially curative operations for residual oligometastatic disease (15.9% vs. 4.3%, p = 0.045). Survival after surgery was prolonged in the after-EST cohort (median 16 months vs. 6 months, p < 0.001), with the stage at initial metastasectomy (stage 4a, hazard ratio [HR] 0.45 (0.28-0.73), p = 0.001) and treatment with immune checkpoint inhibitors (HR 0.38 (0.25-0.60), p < 0.001) associated with prolonged survival.

DISCUSSION

Surgery remains important in the management of stage IV melanoma, with evolving indications and patterns of intervention after the introduction of ESTs. The combination of judicious surgery and EST may improve oncological outcomes.

Apatinib mesylate tablet in the treatment of advanced malignant melanoma

Background

Observing and studying clinical efficacy and safety of apatinib mesylate tablet in the treatment of advanced malignant melanoma (MM).

Methods

Retrospectively analyzing the clinical data of 22 patients with metastatic MM who had failed conventional chemotherapy from June 2016 to January 2018. All patients took 500 mg of apatinib mesylate tablets per day. The efficacy should be evaluated according to RECIST 1.1 criteria. Adverse events (AEs) should be graded according to NCI-CTCAE 4.0.

Results

There were two cases of partial remission (PR), 11 of stable disease (SD) and nine of progressive disease (PD) in the 22 patients with advanced MM, where the objective remission rate (ORR) was 9.1% and the disease control rate (DCR) was 59.1%. The median progression-free survival (PFS) was 7.5 months, and the 6-month progression-free survival rate (PFR) was 54.7%. Six patients died and the overall survival (OS) was not reached. AEs were controllable and all were in Grade 1–3.

Conclusion

Apatinib mesylate tablets have a certain curative effect on patients with malignant melanomas of Stage IV who failed conventional chemotherapy. Apatinib mesylate tablets at a daily dose of 500 mg are well tolerated by most patients.

Deciphering mechanisms of brain metastasis in melanoma - the gist of the matter

Metastasis to distant organs and particularly the brain still represents the most serious obstacle in melanoma therapies. Melanoma cells acquire a phenotype to metastasize to the brain and successfully grow there through complex mechanisms determined by microenvironmental than rather genetic cues. There do appear to be some prerequisites, including the presence of oncogenic BRAF or NRAS mutations and a loss of PTEN. Further mediators of the brain metastatic phenotype appear to be the high activation of the PI3K/AKT or STAT3 pathway or high levels of PLEKHA5 and MMP2 in metastatic cells. A yet undefined subset of brain metastases exhibit a high level of expression of CD271 that is associated with stemness, migration and survival. Hence, CD271 expression may determine specific properties of brain metastatic melanoma cells. Environmental cues - in particular those provided by brain parenchymal cells such as astrocytes - seem to help specifically guide melanoma cells that express CCR4 or CD271, potential "homing receptors". Upon entering the brain, these cells interact with brain parenchyma cells and are thereby reprogrammed to adopt a neurological phenotype. Several lines of evidence suggest that current therapies may have a negative effect by activating a program that drives tumor cells toward stemness and metastasis. Yet significant improvements have expanded the therapeutic options for treating brain metastases from melanoma, by combining potent BRAF inhibitors such as dabrafenib with checkpoint inhibitors or stereotactic surgery. Further progress toward developing new therapeutic strategies will require a more profound understanding of the mechanisms that underlie brain metastasis in melanoma.

Safety and Efficacy of Apatinib Combined with Temozolomide in Advanced Melanoma Patients after Conventional Treatment Failure

OBJECTIVE

Asian melanoma patients, predominantly comprised of acral and mucosal subtypes, might not benefit from immunotherapy and targeted therapy as much as Caucasian patients. Novel treatment strategies are demanded after conventional treatment failure. This was a prospective, single-arm, and single-center dose escalation study to investigate the safety and preliminary efficacy of apatinib combined with temozolomide in heavily treated advanced melanoma patients.

METHODS

Patients were sequentially admitted to four dose-escalating groups of apatinib and temozolomide (three cases in each group) using a traditional 3 + 3 dose escalation design method.

RESULTS

Twelve patients were enrolled between December 2016 and August 2017. Most patients with an acral or mucosal primary origin progressed after immunotherapy or targeted therapy. Dose escalation had been completed without dose-limiting toxicity. Common adverse events included hypertension, hand-foot syndrome, proteinuria, neutropenia, nausea, and fatigue. All adverse events were grade 1 or 2, while the maximum tolerated dose was not reached. Up to January 2018, 1 patient achieved partial response, 9 experienced stable disease, and 2 exhibited progressive disease. The objective response rate and disease control rate were 8.3% and 83%, respectively.

CONCLUSIONS

In conclusion, apatinib combined with temozolomide was well tolerated and has demonstrated efficacy in advanced melanoma patients.

Real-world use, safety, and survival of ipilimumab in metastatic cutaneous melanoma in The Netherlands

Phase III trials with ipilimumab showed an improved survival in patients with metastatic melanoma. We evaluated the use and safety of ipilimumab, and the survival of all patients with metastatic cutaneous melanoma (N=807) receiving ipilimumab in real-world clinical practice in The Netherlands using data from the Dutch Melanoma Treatment Registry. Patients who were registered between July 2012 and July 2015 were included and analyzed according to their treatment status: treatment-naive (N=344) versus previously-treated (N=463). Overall, 70% of treatment-naive patients and 62% of previously-treated patients received all four planned doses of ipilimumab. Grade 3 and 4 immune-related adverse events occurred in 29% of treatment-naive patients and 21% of previously-treated patients. No treatment-related deaths occurred. Median time to first event was 5.4 months [95% confidence interval (CI): 4.7-6.5 months] in treatment-naive patients and 4.4 months (95% CI: 4.0-4.7 months) in previously-treated patients. Median overall survival was 14.3 months (95% CI: 11.6-16.7 months) in treatment-naive patients and 8.7 months (95% CI: 7.6-9.6 months) in previously-treated patients. In both patient groups, an elevated lactate dehydrogenase level (hazard ratio: 2.25 and 1.70 in treatment-naive and previously-treated patients, respectively) and American Joint Committee on Cancer M1c-stage disease (hazard ratio: 1.81 and 1.83, respectively) were negatively associated with overall survival. These real-world outcomes of ipilimumab slightly differed from outcomes in phase III trials. Although phase III trials are crucial for establishing efficacy, real-world data are of great added value enhancing the generalizability of outcomes of ipilimumab in clinical practice.