Actionable Genetic Screens Unveil Targeting of AURKA, MEK, and Fatty Acid Metabolism as an Alternative Therapeutic Approach for Advanced Melanoma.

Despite the remarkable improvements achieved in the management of metastatic melanoma, there are still unmet clinical needs. A considerable fraction of patients does not respond to immune and/or targeted therapies owing to primary and acquired resistance, high-grade immune-related adverse events, and a lack of alternative treatment options. To design effective combination therapies, we set up a functional ex vivo preclinical assay on the basis of a drop-out genetic screen in metastatic melanoma patient-derived xenografts. We showed that this approach can be used to isolate actionable vulnerabilities predictive of drug efficacy. In particular, we highlighted that the dual targeting of AURKA and MAPK/extracellular signal-regulated kinase kinase employing the combination of alisertib and trametinib is highly effective in a cohort of metastatic melanoma patient-derived xenografts, both ex vivo and in vivo. Alisertib and trametinib combination therapy outperforms standard-of-care therapy in both BRAF-mutant patient-derived xenografts and targeted therapy-resistant models. Furthermore, alisertib and trametinib treatment modulates several critical cancer pathways, including an early metabolic reprogramming that leads to the transcriptional upregulation of the fatty acid oxidation pathway. This acquired trait unveiled an additional point of intervention for pharmacological targeting, and indeed, the triple combination of alisertib and trametinib with the fatty acid oxidation inhibitor etomoxir proved to be further beneficial, inducing tumor regression and remarkably prolonging the overall survival of the mice.

In Vivo Anticancer Activity of AZD3965: A Systematic Review.

Proliferating cancer cells have high energy demands, which is mainly obtained through glycolysis. The transmembrane trafficking of lactate, a major metabolite produced by glycolytic cancer cells, relies on monocarboxylate transporters (MCTs). MCT1 optimally imports lactate, although it can work bidirectionally, and its activity has been linked to cancer aggressiveness and poor outcomes. AZD3965, a specific MCT1 inhibitor, was tested both in vitro and in vivo, with encouraging results; a phase I clinical trial has already been undertaken. Thus, analysis of the experimental evidence using AZD3965 in different cancer types could give valuable information for its clinical use. This systematic review aimed to assess the in vivo anticancer activity of AZD3965 either alone (monotherapy) or with other interventions (combination therapy). Study search was performed in nine different databases using the keywords "AZD3965 in vivo" as search terms. The results show that AZD3965 successfully decreased tumor growth and promoted intracellular lactate accumulation, which confirmed its effectiveness, especially in combined therapy. These results support the setup of clinical trials, but other important findings, namely AZD3965 enhanced activity when given in combination with other therapies, or MCT4-induced treatment resistance, should be further considered in the clinical trial design to improve therapy response.

Effective drug treatment identified by in vivo screening in a transplantable patient-derived xenograft model of chronic myelomonocytic leukemia.

To establish novel and effective treatment combinations for chronic myelomonocytic leukemia (CMML) preclinically, we hypothesized that supplementation of CMML cells with the human oncogene Meningioma 1 (MN1) promotes expansion and serial transplantability in mice, while maintaining the functional dependencies of these cells on their original genetic profile. Using lentiviral expression of MN1 for oncogenic supplementation and transplanting transduced primary mononuclear CMML cells into immunocompromised mice, we established three serially transplantable CMML-PDX models with disease-related gene mutations that recapitulate the disease in vivo. Ectopic MN1 expression was confirmed to enhance the proliferation of CMML cells, which otherwise did not engraft upon secondary transplantation. Furthermore, MN1-supplemented CMML cells were serially transplantable into recipient mice up to 5 generations. This robust engraftment enabled an in vivo RNA interference screening targeting CMML-related mutated genes including NRAS, confirming that their functional relevance is preserved in the presence of MN1. The novel combination treatment with azacitidine and the MEK-inhibitor trametinib additively inhibited ERK-phosphorylation and thus depleted the signal from mutated NRAS. The combination treatment significantly prolonged survival of CMML mice compared to single-agent treatment. Thus, we identified the combination of azacitidine and trametinib as an effective treatment in NRAS-mutated CMML and propose its clinical development.

A systematic literature review and network meta-analysis of effectiveness and safety outcomes in advanced melanoma.

BACKGROUND: Although a myriad of novel treatments entered the treatment paradigm for advanced melanoma, there is lack of head-to-head evidence. We conducted a network meta-analysis (NMA) to estimate each treatment's relative effectiveness and safety. METHODS: A systematic literature review (SLR) was conducted in Embase, MEDLINE and Cochrane to identify all phase III randomised controlled trials (RCTs) with a time frame from January 1, 2010 to March 11, 2019. We retrieved evidence on treatment-related grade III/IV adverse events, progression-free survival (PFS) and overall survival (OS). Evidence was synthesised using a Bayesian fixed-effect NMA. Reference treatment was dacarbazine. In accordance with RCTs, dacarbazine was pooled with temozolomide, paclitaxel and paclitaxel plus carboplatin. To increase homogeneity of the study populations, RCTs were only included if patients were not previously treated with novel treatments. RESULTS: The SLR identified 28 phase III RCTs involving 14,376 patients. Nineteen and seventeen treatments were included in the effectiveness and safety NMA, respectively. For PFS, dabrafenib plus trametinib (hazard ratio [HR] PFS: 0.21) and vemurafenib plus cobimetinib (HR PFS: 0.22) were identified as most favourable treatments. Both had, however, less favourable safety profiles. Five other treatments closely followed (dabrafenib [HR PFS: 0.30], nivolumab plus ipilimumab [HR PFS: 0.34], vemurafenib [HR PFS: 0.38], nivolumab [HR PFS: 0.42] and pembrolizumab [HR PFS: 0.46]). In contrast, for OS, nivolumab plus ipilimumab (HR OS: 0.39), nivolumab (HR OS: 0.46) and pembrolizumab (HR OS: 0.50) were more favourable than dabrafenib plus trametinib (HR OS: 0.55) and vemurafenib plus cobimetinib (HR OS: 0.57). CONCLUSIONS: Our NMA identified the most effective treatment options for advanced melanoma and provided valuable insights into each novel treatment's relative effectiveness and safety. This information may facilitate evidence-based decision-making and may support the optimisation of treatment and outcomes in everyday clinical practice.

Budget Impact of Dabrafenib and Trametinib in Combination as Adjuvant Treatment of BRAF V600E/K Mutation-Positive Melanoma from a U.S. Commercial Payer Perspective.

BACKGROUND: Before the approval of dabrafenib and trametinib in combination, there were no approved therapies in the adjuvant setting that target the RAS/RAF/MEK/ERK pathway. OBJECTIVE: To evaluate the budget impact of dabrafenib and trametinib in combination for adjuvant treatment of patients with BRAF V600 mutation-positive resected Stage IIIA, IIIB, or IIIC melanoma from a U.S. commercial payer perspective using data from the COMBI-AD trial, as well as other sources. METHODS: The budget impact of dabrafenib and trametinib in combination for patients with BRAF V600E/K mutation-positive, resected Stage IIIA, IIIB, or IIIC melanoma was evaluated from the perspective of a hypothetical population of 1 million members with demographic characteristics consistent with those of a commercially insured U.S. insurance plan (i.e., adults aged less than 65 years) using an economic model developed in Microsoft Excel. The model compared melanoma-related health care costs over a 3-year projection period under 2 scenarios: (1) a reference scenario in which dabrafenib and trametinib are assumed to be unavailable for adjuvant therapy and (2) a new scenario in which the combination is assumed to be available. Treatments potentially displaced by dabrafenib and trametinib were assumed to include observation, high-dose interferon alpha-2b, ipilimumab, and nivolumab. Costs considered in the model include those of adjuvant therapies and treatment of locoregional and distant recurrences. The numbers of patients eligible for treatment with dabrafenib and trametinib were based on data from cancer registries, published sources, and assumptions. Treatment mixes under the reference and new scenarios were based on market research data, clinical expert opinion, and assumptions. Probabilities of recurrence and death were based on data from the COMBI-AD trial and an indirect treatment comparison. Medication costs were based on wholesale acquisition cost prices. Costs of distant recurrence were from a health insurance claims study. RESULTS: In a hypothetical population of 1 million commercially insured members, 48 patients were estimated to become eligible for treatment with dabrafenib and trametinib in combination over the 3-year projection period; in the new scenario, 10 patients were projected to receive such treatment. Cumulative costs of melanoma-related care were estimated to be $6.3 million in the reference scenario and $6.9 million in the new scenario. The budget impact of dabrafenib and trametinib in combination was an increase of $549 thousand overall and 1.5 cents per member per month. CONCLUSIONS: For a hypothetical U.S. commercial health plan of 1 million members, the budget impact of dabrafenib and trametinib in combination as adjuvant treatment for melanoma is likely to be relatively modest and within the range of published estimates for oncology therapies. These results may assist payers in making coverage decisions regarding the use of adjuvant dabrafenib and trametinib in melanoma. DISCLOSURES: Funding for this research was provided to Policy Analysis Inc. (PAI) by Novartis Pharmaceuticals. Stellato, Moynahan, and Delea are employed by PAI. Ndife, Koruth, Mishra, and Gunda are employed by Novartis. Ghate was employed by Novartis at the time of this study and is shareholder in Novartis, Provectus Biopharmaceuticals, and Mannkind Corporation. Gerbasi was employed by PAI at the time of this study and is currently an employee, and stockholder, of Sage Therapeutics. Delea reports grant funding from Merck and research funding from Amgen, Novartis, Sanofi, Seattle Genetics, Takeda, Jazz, EMD Serono, and 21st Century Oncology, unrelated to this work.

Integrative Exome and Transcriptome Analysis of Conjunctival Melanoma and Its Potential Application for Personalized Therapy.

Importance: Greater understanding of molecular features of conjunctival melanoma (CM) may improve its clinical management. Objective: To evaluate molecular features of CM and application of this information into clinical care. Design, Setting, and Participants: In a prospective case series of CM with integrative exome and transcriptome analysis, 8 patients at an academic ocular oncology setting were evaluated. The study was conducted from November 2015 to March 2018. Interventions/Exposures: Integrative exome and transcriptome analysis of CMs and clinical management of a patient's care by using this information. Main Outcomes and Measures: Molecular characterization of CM and its potential clinical application. Results: In the 8 patients (4 men) included in analysis, 4 subgroups of CM were observed, including the BRAF V600E mutation in 1 tumor, NRAS Q61R mutation in 3 tumors, NF1 mutations (Q1188X, R440X, or M1215K+ S15fs) in 3 tumors, and triple-wild type (triple-WT) in 1 tumor. The triple-WT case had CCND1 amplification and mutation in the CIC gene (Q1508X). Five tumors, including the triple-WT, also harbored mutations in MAPK genes. In addition to the genes linked to mitogen-activated protein kinase and phosphoinositol 3-kinase pathways, those involved in cell cycle and/or survival, ubiquitin-mediated protein degradation, and chromatin remodeling/epigenetic regulation (ATRX being the most frequently mutated: noted in 5 tumors) may play an important role. Other frequently mutated genes included PREX2 (n = 3), APOB (n = 4), and RYR1/2 (n = 4), although their relevance remains to be determined. The mutation burden ranged from 1.1 to 15.6 mutations per megabase (Mut/Mb) and was 3.3 Mut/Mb or less in 3 tumors and more than 10 Mut/Mb in 2 tumors. A patient with a large tumor and BRAF V600E mutation was treated with combined systemic BRAF (dabrafenib) and MEK (trametinib) inhibitors. After 3 months of therapy, her CM responded substantially and the residual tumor was removed by local surgical excision. Conclusions and Relevance: The NRAS Q61R and NF1 mutations were more common than the BRAF V600E mutation in this series. Although small tumors (where incisional biopsy is not indicated) are treated with surgical excision regardless of mutational profile, in large tumors carrying the BRAF V600E mutation, neoadjuvant therapy with combined systemic BRAF and MEK inhibitors followed by local excision may be used as an alternative to exenteration. Integrative omics analysis of CM may be informative and guide clinical management and treatment in selected cases.

Inhibition of the ERK1/2-mTORC1 axis ameliorates proteinuria and the fibrogenic action of transforming growth factor-ß in Adriamycin-induced glomerulosclerosis.

Transforming growth factor-ß (TGF-ß) plays crucial roles in the development of focal segmental glomerulosclerosis, but key molecular pathways remain unknown. Here, we identified the regulation of mammalian target of rapamycin complex1 (mTORC1) by TGF-ß via ERK1/2 in the Adriamycin-induced murine model of focal segmental glomerulosclerosis. Adriamycin administration elicited early activation of TGF-ß-ERK1/2-mTORC1 in podocytes, which persisted at later stages of albuminuria and glomerulosclerosis. Phosphorylation of the TGF-ß receptor-I (TGF-ßRI), Smad3, ERK1/2 and ribosomal protein S6 were evident in the glomeruli of adriamycin-treated mice. Targeting TGFß-RI and mTORC1 with pharmacological inhibitors suppressed TGF-ß signaling in glomeruli and significantly reduced albuminuria, glomerulosclerosis, protein levels of collagen 4α3, plasminogen activator inhibitor-1, and vimentin and restored mRNA levels of podocyte markers. Low dose US Food and Drug Administration (FDA)-approved MEK/ERK inhibitor trametinib/GSK1120212 blunted TGF-ß1-induced mTORC1 activation in podocytes, ameliorated up-regulation of TGF-ß, plasminogen activator inhibitor-1, monocyte chemoattractant protein-1, fibronectin and α-smooth muscle actin and prevented albuminuria and glomerulosclerosis with improved serum albumin. In cultured podocytes, this pathway was found to be associated with translation of fibrogenic collagen 4α3 and plasminogen activator inhibitor-1, without influencing their transcription. Notably, rapamycin suppressed upstream p-TGF-ßRI, p-Smad3 and p-ERK1/2, and trametinib down-regulated upstream p-Smad3 in ex vivo and in vivo studies, indicating that harmful paracrine signaling among glomerular cells amplified the TGF-ß-ERK1/2-mTORC1 axis by forming a positive feedback loop. Thus, an accentuated TGF-ß-ERK1/2-mTORC1 pathway is suggested as a central upstream mediator to develop proteinuria and glomerulosclerosis. Hence, preventing activation of this vicious loop by trametinib may offer a new therapeutic strategy for glomerular disease treatment.

The novel inhibitor PRI-724 for Wnt/ß-catenin/CBP signaling ameliorates bleomycin-induced pulmonary fibrosis in mice.

Purpose/Aim of the Study: Wnt/ß-catenin signaling was reported to be activated in pulmonary fibrosis, and was focused on as a target for antifibrotic therapy. However, the mechanism how the inhibition of Wnt/ß-catenin signaling ameliorate pulmonary fibrosis has not been fully elucidated. The purpose of this study is to explore the target cells of Wnt/ß-catenin inhibition in pulmonary fibrosis and to examine the antifibrotic effect of the novel inhibitor PRI-724 specifically disrupting the interaction of ß-catenin and CBP. Materials and Methods: The effect of C-82, an active metabolite of PRI-724, on the expression of TGF-ß1 and α-smooth muscle actin (SMA) was examined on fibroblasts and macrophages. We also examined the effects of PRI-724 in mouse model of bleomycin-induced pulmonary fibrosis. Results: The activation and increased accumulation of ß-catenin in the canonical pathway were detected in lung fibroblasts as well as macrophages stimulated by Wnt3a using Western blotting. Treatment with C-82 reduced CBP protein and increased p300 protein binding to ß-catenin in the nucleus of lung fibroblasts. In addition, C-82 inhibited the expression of SMA in lung fibroblasts treated with TGF-ß, indicating the inhibition of myofibroblast differentiation. In the fibrotic lungs induced by bleomycin, ß-catenin was stained strongly in macrophages, but the staining of ß-catenin in alveolar epithelial cells and fibroblasts was weak. The administration of PRI-724 ameliorated pulmonary fibrosis induced by bleomycin in mice when administered with a late, but not an early, treatment schedule. Analysis of bronchoalveolar fluid (BALF) showed a decreased number of alveolar macrophages. In addition, the level of TGF-ß1 in BALF was decreased in mice treated with PRI-724. C-82 also inhibited the production of TGF-ß1 by alveolar macrophages. Conclusions: These results suggest that the ß-catenin/CBP inhibitor PRI-724 is a potent antifibrotic agent that acts by modulating the activity of macrophages in the lungs.

Safety and efficacy of the human neutrophil elastase inhibitor BAY 85-8501 for the treatment of non-cystic fibrosis bronchiectasis: A randomized controlled trial.

BACKGROUND: There are only limited treatment options for patients with non-cystic fibrosis bronchiectasis (non-CF BE). Human neutrophil elastase (HNE) is a mediator of tissue destruction in non-CF BE. BAY 85-8501, a selective and reversible HNE inhibitor, could represent a new treatment option for this disease. METHODS: This was a phase 2a, randomized, placebo-controlled, double-blind, parallel-group study. The primary objective was to assess the safety and tolerability of 1 mg BAY 85-8501 once daily (OD) for 28 days compared with placebo in patients with non-CF BE. Secondary objectives were to investigate the effects of 4 weeks of treatment with BAY 85-8501 on health-related quality of life, pulmonary function, and inflammatory and tissue damage biomarkers in sputum, blood and/or urine, and to evaluate the pharmacokinetics of BAY 85-8501. RESULTS: Overall, 94 patients (mean age, 66 years; 53% male) were randomized (n = 47 per group), and 82 completed the study (BAY 85-8501, n = 37; placebo, n = 45). Treatment-emergent adverse events (TEAEs) occurred in 31 patients (66%) taking BAY 85-8501 and in 36 patients (77%) taking placebo, and were mostly mild or moderate. The serious TEAEs (BAY 85-8501, n = 3; placebo, n = 1) were not considered to be study-drug related. There were no changes in pulmonary function parameters from baseline to end of treatment, and health-related quality of life did not improve in any group. HNE activity in blood after zymosan challenge decreased significantly with BAY 85-8501 treatment (P = 0.0250 versus placebo). There were no significant differences in other biomarkers between treatment groups, with the exception of a small increase in interleukin-8 levels in sputum in the BAY 85-8501 group. Trough plasma concentrations of BAY 85-8501 plateaued after 2 weeks. CONCLUSIONS: 1 mg BAY 85-8501 OD had a favourable safety and tolerability profile when administered for 28 days to patients with non-CF BE. Further studies with a longer treatment duration are needed to evaluate the potential clinical efficacy in this study population.

Discovery of chiral dihydropyridopyrimidinones as potent, selective and orally bioavailable inhibitors of AKT.

During the course of our research efforts to develop potent and selective AKT inhibitors, we discovered enatiomerically pure substituted dihydropyridopyrimidinones (DHP) as potent inhibitors of protein kinase B/AKT with excellent selectivity against ROCK2. A key challenge in this program was the poor physicochemical properties of the initial lead compound 5. Integration of structure-based drug design and physical properties-based design resulted in replacement of a highly hydrophobic poly fluorinated aryl ring by a simple trifluoromethyl that led to identification of compound 6 with much improved physicochemical properties. Subsequent SAR studies led to the synthesis of new pyran analog 7 with improved cell potency. Further optimization of pharmacokintetics properties by increasing permeability with appropriate fluorinated alkyl led to compound 8 as a potent, selective AKT inhibitors that blocks the phosphorylation of GSK3ß in vivo and had robust, dose and concentration dependent efficacy in the U87MG tumor xenograft model.

Copper Silicate Hollow Microspheres-Incorporated Scaffolds for Chemo-Photothermal Therapy of Melanoma and Tissue Healing.

The treatment of melanoma requires complete removal of tumor cells and simultaneous tissue regeneration of tumor-initiated cutaneous defects. Herein, copper silicate hollow microspheres (CSO HMSs)-incorporated bioactive scaffolds were designed for chemo-photothermal therapy of skin cancers and regeneration of skin tissue. CSO HMSs were synthesized with interior hollow and external nanoneedle microstructure, showing excellent drug-loading capacity and photothermal effects. With incorporation of drug-loaded CSO HMSs into the electrospun scaffolds, the composite scaffolds exhibited excellent photothermal effects and controlled NIR-triggered drug release, leading to distinctly synergistic chemo-photothermal therapy of skin cancer both in vitro and in vivo. Furthermore, such CSO HMSs-incorporated scaffolds could promote proliferation and attachment of normal skin cells and accelerate skin tissue healing in tumor-bearing and diabetic mice. Taken together, CSO HMSs-incorporated scaffolds may be used for complete eradication of the remaining tumor cells after surgery and simultaneous tissue healing, which offers an effective strategy for therapy and regeneration of tumor-initiated tissue defects.

In vivo phenotypic screening: clinical proof of concept for a drug repositioning approach.

In vivo phenotypic screening and drug repositioning are strategies developed as alternatives to underperforming hypothesis-driven molecular target based drug discovery efforts. This article reviews examples of drugs identified by phenotypic observations and describes the use of the theraTRACE®in vivo screening platform for finding and developing new indications for discontinued clinical compounds. Clinical proof-of-concept for the platform is exemplified by MLR-1023, a repositioned compound that has recently shown significant clinical efficacy in Type 2 diabetes patients. These findings validate an in vivo screening approach for drug development and underscore the importance of alternatives to target and mechanism based strategies that have failed to produce adequate numbers of new medicines.

Therapeutic Potential of Targeting Wnt/ß-Catenin Pathway in Treatment of Colorectal Cancer: Rational and Progress.

Wnt/ß-catenin pathway is one of the main/frequent dysregulated pathways in several tumor types, including colon cancer. Aberrant activation of this pathway is associated with cell proliferation, invasive behaviors, and cell resistance, suggesting its potential value as a therapeutic target in treatment of CRC. Several agents have been developed for targeting of this pathway (e.g, natural agents: curcumin, 3,3-diindolylmethane, phytoestrogen; Synthetic/small Wnt inhibitors: Rofecoxib; PRI-724, CWP232291; and monoclonal antibody against frizzled receptors, Vanituctumab). This review summarizes the current knowledge about the therapeutic potential of targeting Wnt pathway with particular emphasis on preclinical/clinical studies in treatment of colorectal cancer. J. Cell. Biochem. 118: 1979-1983, 2017. © 2017 Wiley Periodicals, Inc.

The distribution of BRAF gene fusions in solid tumors and response to targeted therapy.

Although the BRAF V600E base substitution is an approved target for the BRAF inhibitors in melanoma, BRAF gene fusions have not been investigated as anticancer drug targets. In our study, a wide variety of tumors underwent comprehensive genomic profiling for hundreds of known cancer genes using the FoundationOne™ or FoundationOne Heme™ comprehensive genomic profiling assays. BRAF fusions involving the intact in-frame BRAF kinase domain were observed in 55 (0.3%) of 20,573 tumors, across 12 distinct tumor types, including 20 novel BRAF fusions. These comprised 29 unique 5' fusion partners, of which 31% (9) were known and 69% (20) were novel. BRAF fusions included 3% (14/531) of melanomas; 2% (15/701) of gliomas; 1.0% (3/294) of thyroid cancers; 0.3% (3/1,062) pancreatic carcinomas; 0.2% (8/4,013) nonsmall-cell lung cancers and 0.2% (4/2,154) of colorectal cancers, and were enriched in pilocytic (30%) vs. nonpilocytic gliomas (1%; p < 0.0001), Spitzoid (75%) vs. nonSpitzoid melanomas (1%; p = 0.0001), acinar (67%) vs. nonacinar pancreatic cancers (<1%; p < 0.0001) and papillary (3%) vs. nonpapillary thyroid cancers (0%; p < 0.03). Clinical responses to trametinib and sorafenib are presented. In conclusion, BRAF fusions are rare driver alterations in a wide variety of malignant neoplasms, but enriched in Spitzoid melanoma, pilocytic astrocytomas, pancreatic acinar and papillary thyroid cancers.

RX-P873, a Novel Protein Synthesis Inhibitor, Accumulates in Human THP-1 Monocytes and Is Active against Intracellular Infections by Gram-Positive (Staphylococcus aureus) and Gram-Negative (Pseudomonas aeruginosa) Bacteria.

The pyrrolocytosine RX-P873, a new broad-spectrum antibiotic in preclinical development, inhibits protein synthesis at the translation step. The aims of this work were to study RX-P873's ability to accumulate in eukaryotic cells, together with its activity against extracellular and intracellular forms of infection by Staphylococcus aureus and Pseudomonas aeruginosa, using a pharmacodynamic approach allowing the determination of maximal relative efficacies (Emax values) and bacteriostatic concentrations (Cs values) on the basis of Hill equations of the concentration-response curves. RX-P873's apparent concentration in human THP-1 monocytes was about 6-fold higher than the extracellular one. In broth, MICs ranged from 0.125 to 0.5 mg/liter (S. aureus) and 2 to 8 mg/liter (P. aeruginosa), with no significant shift in these values against strains resistant to currently used antibiotics being noted. In concentration-dependent experiments, the pharmacodynamic profile of RX-P873 was not influenced by the resistance phenotype of the strains. Emax values (expressed as the decrease in the number of CFU from that in the initial inoculum) against S. aureus and P. aeruginosa reached more than 4 log units and 5 log units in broth, respectively, and 0.7 log unit and 2.7 log units in infected THP-1 cells, respectively, after 24 h. Cs values remained close to the MIC in all cases, making RX-P873 more potent than antibiotics to which the strains were resistant (moxifloxacin, vancomycin, and daptomycin for S. aureus; ciprofloxacin and ceftazidime for P. aeruginosa). Kill curves in broth showed that RX-P873 was more rapidly bactericidal against P. aeruginosa than against S. aureus. Taken together, these data suggest that RX-P873 may constitute a useful alternative for infections involving intracellular bacteria, especially Gram-negative species.

Trametinib in the treatment of melanoma.

INTRODUCTION: Aberrant MAPK pathway signaling is a hallmark of melanoma. Mitogen/extracellular signal-regulated kinase (MEK) 1/2 are integral components of MAPK signaling. Several MEK inhibitors have demonstrated activity as single agents and in combination with other therapies. Trametinib was the first MEK inhibitor approved for use in treatment of advanced BRAF(V600) mutant melanoma as a single agent and in combination with BRAF inhibitor, dabrafenib. AREAS COVERED: In this article, we discuss the underlying biology of MEK inhibition and its rationale in melanoma treatment with special emphasis on the clinical development of trametinib, from initial Phase I studies to randomized Phase II and III studies, both as monotherapy and in combination with other therapeutics. Furthermore, we briefly comment on trametinib for NRAS mutant and other non-BRAF mutant subsets of melanoma. EXPERT OPINION: Trametinib is a novel oral MEK inhibitor with clinical activity in BRAF(V600) mutant metastatic melanoma alone and in combination with dabrafenib. Trametinib is currently being explored in other genetic subsets as well, particularly those with NRAS mutations or atypical BRAF alterations. Furthermore, to maximize efficacy and overcome acquired resistance, studies evaluating the combination of trametinib with other targeted agents and immunotherapy are underway.

Synthesis and biological evaluation of 5-nitropyrimidine-2,4-dione analogues as inhibitors of nitric oxide and iNOS activity.

Fifty two compounds based on 5-nitropyrimidine-2,4-dione moiety have been synthesized and evaluated for their inhibitory potency on the production of nitric oxide. Among them, compound 36 inhibited the production of nitric oxide (IC50 : 8.6 µm) on lipopolysaccharide-induced RAW 264.7 cells and inducible nitric oxide synthase activity (IC50 : 6.2 µm), as well as exerted no potential cytotoxicity (IC50 > 80.0 µm). Docking study confirmed that compound 36 was an inducible nitric oxide synthase inhibitor with perfect binding to the active site of inducible nitric oxide synthase. At a dose of 10 mg/kg, oral administration of 36 possessed protective properties in carrageenan-induced paw edema of male ICR mice.

The discovery of a highly selective 5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one SIRT2 inhibitor that is neuroprotective in an in vitro Parkinson's disease model.

Sirtuins, NAD(+) -dependent histone deacetylases (HDACs), have recently emerged as potential therapeutic targets for the treatment of a variety of diseases. The discovery of potent and isoform-selective inhibitors of this enzyme family should provide chemical tools to help determine the roles of these targets and validate their therapeutic value. Herein, we report the discovery of a novel class of highly selective SIRT2 inhibitors, identified by pharmacophore screening. We report the identification and validation of 3-((2-methoxynaphthalen-1-yl)methyl)-7-((pyridin-3-ylmethyl)amino)-5,6,7,8-tetrahydrobenzo[4,5]thieno[2,3-d]pyrimidin-4(3H)-one (ICL-SIRT078), a substrate-competitive SIRT2 inhibitor with a Ki value of 0.62 ± 0.15 µM and more than 50-fold selectivity against SIRT1, 3 and 5. Treatment of MCF-7 breast cancer cells with ICL-SIRT078 results in hyperacetylation of α-tubulin, an established SIRT2 biomarker, at doses comparable with the biochemical IC50 data, while suppressing MCF-7 proliferation at higher concentrations. In concordance with the recent reports that suggest SIRT2 inhibition is a potential strategy for the treatment of Parkinson's disease, we find that compound ICL-SIRT078 has a significant neuroprotective effect in a lactacystin-induced model of Parkinsonian neuronal cell death in the N27 cell line. These results encourage further investigation into the effects of ICL-SIRT078, or an optimised derivative thereof, as a candidate neuroprotective agent in in vivo models of Parkinson's disease.

Current systemic therapies for melanoma.

BACKGROUND: Systemic agents are used in melanoma for adjuvant therapy and to treat metastatic disease. Currently, interferon-α is the only agent approved for adjuvant therapy. Six drugs are FDA approved for metastatic disease: dacarbazine, interleukin-2 (IL-2), vemurafenib, ipilimumab, dabrafenib, and trametinib. Vemurafenib and ipilimumab were approved in 2011, whereas dabrafenib and trametinib were approved in 2013. OBJECTIVE: This review will update the practicing dermatologist on the differences in efficacy, adverse events, and cost of systemic therapies available for the treatment of melanoma. MATERIALS AND METHODS: This article is a review of the current literature on systemic therapies for advanced melanoma. Key search words included "advanced melanoma," "systemic therapy," and "adjuvant therapy" with particular focus on the past 20 years. RESULTS: Before 2011, dacarbazine and IL-2 were the only FDA approved therapies for metastatic melanoma, and IFN-α is the only approved agent for adjuvant therapy. The new agents vemurafenib, ipilimumab, dabrafenib, and trametinib are the first to have improved overall survival in Phase III studies in comparison with other systemic therapies. CONCLUSION: Despite new developments, there remains a significant need for better therapies with improved long-term efficacy and decreased toxicity.