PPRX-1701, a nanoparticle formulation of 6'-bromoindirubin acetoxime, improves delivery and shows efficacy in preclinical GBM models.

Derivatives of the Chinese traditional medicine indirubin have shown potential for the treatment of cancer through a range of mechanisms. This study investigates the impact of 6'-bromoindirubin-3'-acetoxime (BiA) on immunosuppressive mechanisms in glioblastoma (GBM) and evaluates the efficacy of a BiA nanoparticle formulation, PPRX-1701, in immunocompetent mouse GBM models. Transcriptomic studies reveal that BiA downregulates immune-related genes, including indoleamine 2,3-dioxygenase 1 (IDO1), a critical enzyme in the tryptophan-kynurenine-aryl hydrocarbon receptor (Trp-Kyn-AhR) immunosuppressive pathway in tumor cells. BiA blocks interferon-γ (IFNγ)-induced IDO1 protein expression in vitro and enhances T cell-mediated tumor cell killing in GBM stem-like cell co-culture models. PPRX-1701 reaches intracranial murine GBM and significantly improves survival in immunocompetent GBM models in vivo. Our results indicate that BiA improves survival in murine GBM models via effects on important immunotherapeutic targets in GBM and that it can be delivered efficiently via PPRX-1701, a nanoparticle injectable formulation of BiA.

The Effect of Dual Bioactive Compounds Artemisinin and Metformin Co-loaded in PLGA-PEG Nano-particles on Breast Cancer Cell lines: Potential Apoptotic and Anti-proliferative Action.

The most prevalent malignancy among women is breast cancer. Phytochemicals and their derivatives are rapidly being recognized as possible cancer complementary therapies because they can modify signaling pathways that lead to cell cycle control or directly alter cell cycle regulatory molecules. The phytochemicals' poor bioavailability and short half-life make them unsuitable as anticancer drugs. Applying PLGA-PEG NPs improves their solubility and tolerance while also reducing drug adverse effects. According to the findings, combining anti-tumor phytochemicals can be more effective in regulating several signaling pathways linked to tumor cell development. The point of the study was to compare the anti-proliferative impacts of combined artemisinin and metformin on cell cycle arrest and expression of cyclin D1 and apoptotic genes (bcl-2, Bax, survivin, caspase-7, and caspase-3), and also hTERT genes in breast cancer cells. T-47D breast cancer cells were treated with different concentrations of metformin (MET) and artemisinin (ART) co-loaded in PLGA-PEG NPs and free form. The MTT test was applied to assess drug cytotoxicity in T47D cells. The cell cycle distribution was investigated using flow cytometry and the expression levels of cyclin D1, hTERT, Bax, bcl-2, caspase-3, and caspase-7, and survivin genes were then determined using real-time PCR. The findings of the MTT test and flow cytometry revealed that each state was cytotoxic to T47D cells in a time and dose-dependent pattern. Compared to various state of drugs (free and nano state, pure and combination state) Met-Art-PLGA/PEG NPs demonstrated the strongest anti-proliferative impact and considerably inhibited the development of T-47D cells; also, treatment with nano-formulated forms of Met-Art combination resulted in substantial downregulation of hTERT, Bcl-2, cyclin D1, survivin, and upregulation of caspase-3, caspase-7, and Bax, in the cells, as compared to the free forms, as indicated by real-time PCR findings. The findings suggested that combining an ART/MET-loaded PLGA-PEG NP-based therapy for breast cancer could significantly improve treatment effectiveness.

Anticancer potential of indirubins in medicinal chemistry: Biological activity, structural modification, and structure-activity relationship.

Indirubin is the crucial ingredient of Danggui Longhui Wan and Qing-Dai, traditional Chinese medicine herbal formulas used for the therapy of chronic myelocytic leukemia in China for hundreds of years. Although the monomeric indirubin has been used in China for the treatment human chronic myelocytic leukemia. However, due to low water solubility, poor pharmacokinetic properties and low therapeutic effects are the major obstacle, and had significantly limited its clinical application. Consequently, the attractive anticancer profile of indirubin has enthused numerous researchers to discover novel indirubin derivatives with improved pharmacodynamic activity as well as good pharmacokinetic property. In this paper, we comprehensively review the recent progress of anticancer potential of indirubins, structural modification and structure-activity relationship, which may provide useful direction for the further development of novel indirubins with improved pharmacological profiles for the treatment of various types of cancer.

Blockade of Indoleamine 2, 3-dioxygenase 1 ameliorates hippocampal neurogenesis and BOLD-fMRI signals in chronic stress precipitated depression.

Indoleamine 2, 3-dioxygenase 1 (IDO1) has been implicated in the pathogenesis of depression, though its molecular mechanism is still poorly understood. We investigated the molecular mechanism of IDO1 in depression by using the chronic unpredictable mild stress (CUMS) model in Ido1-/- mice and WT mice. The brain blood oxygen level dependent (BOLD) signals in mice were collected by functional magnetic resonance imaging (fMRI) technology. IDO1 inhibitor INCB024360 was intervened in dorsal raphe nucleus (DRN) through stereotactic injection. We found an elevation of serum IDO1 activity and decreased 5-HT in CUMS mice, and the serum IDO1 activity was negatively correlated with 5-HT level. Consistently, IDO1 was increased in hippocampus and DRN regions, accompanied by a reduction of hippocampal BDNF levels in mice with CUMS. Specifically, pharmacological inhibition of IDO1 activity in the DRN alleviated depressive-like behaviour with improving hippocampal BDNF expression and neurogenesis in CUMS mice. Furthermore, ablation of Ido1 exerted stress resistance and decreased the sensitivity of depression in CUMS mice with the stable BOLD signals, BDNF expression and neurogenesis in hippocampus. Thus, IDO1 hyperactivity played crucial roles in modulating 5-HT metabolism and BDNF function thereby impacting outcomes of hippocampal neurogenesis and BOLD signals in depressive disorder.

Blockage of UCHL1 activity attenuates cardiac remodeling in spontaneously hypertensive rats.

Cardiac remodeling is an important pathological process ultimately leading to heart failure. Ubiquitin carboxy-terminal hydrolase 1 (UCHL1) is a deubiquitinase that plays a critical role in neurodegenerative diseases and cancer. However, its role in cardiac remodeling in spontaneously hypertensive rats remains unclear. Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHRs) were administered the UCHL1 inhibitor LDN-57444 (20 µg/kg/day) from 2 months of age for 4 months. Blood pressure, cardiac hypertrophy, fibrosis, inflammation, and oxidative stress were evaluated by the tail-cuff system, echocardiography, and histological analysis. Gene and protein expression levels were examined by real-time PCR and immunoblotting analysis. At 6 months of age, the expression of UCHL at the mRNA and protein levels was significantly upregulated in SHRs compared with WKYs. Moreover, systolic blood pressure, cardiac performance, left ventricular (LV) hypertrophy, fibrosis, inflammation, and superoxide production were significantly increased in SHRs compared with WKYs, and these effects were markedly attenuated by LDN-57444 after 4 months of administration. These beneficial actions were possibly associated with a reduction in blood pressure and inactivation of multiple signaling pathways, including AKT, ERK1/2, STAT3, calcineurin A, TGF-ß/Smad2/3, and NF-κB. In conclusion, the results indicate that UCHL1 is involved in hypertensive cardiac remodeling in SHRs, and targeting UCHL1 activity may be a novel potential therapeutic approach for the treatment of hypertensive heart diseases.

Antihypertensive activity of a new c-Jun N-terminal kinase inhibitor in spontaneously hypertensive rats.

c-Jun N-terminal kinases (JNKs) are involved in the myocardial and aortic remodeling, increased arterial tone, and arterial blood pressure elevation associated with hypertension. The aim of the present study was to investigate the antihypertensive effect of a new JNK inhibitor, 1H-indeno[1,2-b]quinoxalin-11-one oxime sodium salt (IQ-1S), on spontaneously hypertensive rats (SHRs). Experiments were performed using normotensive Wistar-Kyoto (WKY) rats and SHRs. Experimental groups of SHRs received IQ-1S intragastrically for 6 weeks in daily doses of 5 and 50 mg/kg; experimental groups of WKY rats received 50 mg/kg IQ-1S according to the same regimen. The IQ-1S administration regimen induced decreases in systolic blood pressure, mean arterial blood pressure, total peripheral resistance, blood viscosity, hematocrit, myocardial cell cross-sectional area, and aortic wall thickness in SHRs vs untreated SHRs. There were no significant differences in systolic blood pressure values between the control and experimental groups of WKY rats during the treatment period. A concentration-dependent decrease in the tone of carotid arterial rings isolated from SHRs was observed after JNK inhibitor application in vitro. Application of the JNK inhibitor diminished endothelin-1 secretion by human umbilical vein endothelial cells in vitro. The main mechanisms of the antihypertensive effect of IQ-1S included the attenuation of blood viscosity due to decreased hematocrit, a vasodilatory effect on arterial smooth muscle cells, and a decrease in endothelin-1 production by endothelial cells.

Broccoli sprout supplementation in patients with advanced pancreatic cancer is difficult despite positive effects-results from the POUDER pilot study.

Pancreatic ductal adenocarcinoma is a highly aggressive malignancy with short survival and limited therapeutic options. Broccoli sulforaphane is a promising new treatment due to the results of recent epidemiological, experimental and patient studies. Upon approval from the ethics committee and registration at ClinicalTrials.gov, 40 patients with palliative chemotherapy were placed into a placebo and treatment group in an unblinded fashion. Fifteen capsules with pulverized broccoli sprouts containing 90 mg/508 µmol sulforaphane and 180 mg/411 µmol glucoraphanin or methylcellulose were administered daily for up to 1 year. Twenty-nine patients were included in the treatment group and 11 patients were in the placebo group; these patients were followed for up to 1 year. The patient characteristics, overall survival and feasibility were assessed. Compared to those of the placebo group, the mean death rate was lower in the treatment group during the first 6 months after intake (day 30: 0%/18%, day 90: 0%/25%, and day 180: 25%/43%), and Kaplan-Meier analysis revealed a higher survival rate. There was a high drop-out rate (72% in the treatment group and 55% in the placebo group) after 1 year. We concluded from the Karnofsky index that the broccoli sprouts did not impact patient's self-care and overall abilities severely. The intake of 15 capsules daily was difficult for some patients, and the broccoli sprouts sometimes increased digestive problems, nausea and emesis. We did not obtain statistically significant results (p = 0.291 for the endpoint at day 180), but the knowledge about the feasibility is the basis for the development of new sulforaphane drugs.

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.

Synthesis of Isoxazolines by the Electrophilic Chalcogenation of ß,γ-Unsaturated Oximes: Fishing Novel Anti-Inflammatory Agents.

Herein, we describe a new strategy to prepare chalcogen-functionalized isoxazolines. The strategy involves the reaction of ß,γ-unsaturated oximes with electrophilic selenium and tellurium species, affording 19 new selenium- and tellurium-containing isoxazolines in good yields after 1 h at room temperature. The method was efficiently extended to the synthesis of 5 new (bis)isoxazoline ditellurides. One of the prepared compounds, 3-phenyl-5-((phenylselanyl)methyl)-isoxazoline, demonstrated better anti-inflammatory and antiedematogenic effects than the reference drug Celecoxib.

The Anti-Candida albicans Agent 4-AN Inhibits Multiple Protein Kinases.

Small molecules containing quinone and/or oxime moieties have been found as promising anti-fungal agents. One of them is 4-AN, a recently reported potent anti-Candida compound, which inhibits the formation of hyphae, decreases the level of cellular phosphoproteome, and finally shows no toxicity towards human erythrocytes and zebrafish embryos. Here, further research on 4-AN is presented. The results revealed that the compound: (i) Kills Candida clinical isolates, including these with developed antibiotic resistance, (ii) affects mature biofilm, and (iii) moderately disrupts membrane permeability. Atomic force microscopy studies revealed a slight influence of 4-AN on the cell surface architecture. 4-AN was also shown to inhibit multiple various protein kinases, a characteristic shared by most of the ATP-competitive inhibitors. The presented compound can be used in novel strategies in the fight against candidiasis, and reversible protein phosphorylation should be taken into consideration as a target in designing these strategies.

Analgesic and Anti-Inflammatory Effects of the Novel Semicarbazide-Sensitive Amine-Oxidase Inhibitor SzV-1287 in Chronic Arthritis Models of the Mouse.

Semicarbazide-sensitive amine oxidase (SSAO) catalyses oxidative deamination of primary amines. Since there is no data about its function in pain and arthritis mechanisms, we investigated the effects of our novel SSAO inhibitor SzV-1287 in chronic mouse models of joint inflammation. Effects of SzV-1287 (20 mg/kg i.p./day) were investigated in the K/BxN serum-transfer and complete Freund's adjuvant (CFA)-evoked active immunization models compared to the reference SSAO inhibitor LJP-1207. Mechanonociception was assessed by aesthesiometry, oedema by plethysmometry, clinical severity by scoring, joint function by grid test, myeloperoxidase activity by luminescence, vascular leakage by fluorescence in vivo imaging, histopathological changes by semiquantitative evaluation, and cytokines by Luminex assay. SzV-1287 significantly inhibited hyperalgesia and oedema in both models. Plasma leakage and keratinocyte chemoattractant production in the tibiotarsal joint, but not myeloperoxidase activity was significantly reduced by SzV-1287 in K/BxN-arthritis. SzV-1287 did not influence vascular and cellular mechanisms in CFA-arthritis, but significantly decreased histopathological alterations. There was no difference in the anti-hyperalgesic and anti-inflammatory actions of SzV-1287 and LJP-1207, but only SzV-1287 decreased CFA-induced tissue damage. Unlike SzV-1287, LJP-1207 induced cartilage destruction, which was confirmed in vitro. SzV-1287 exerts potent analgesic and anti-inflammatory actions in chronic arthritis models of distinct mechanisms, without inducing cartilage damage.

TRPA1 and TRPV1 Antagonists Do Not Inhibit Human Acidosis-Induced Pain.

Acidosis occurs in a variety of pathophysiological and painful conditions where it is thought to excite or contribute to excitation of nociceptive neurons. Despite potential clinical relevance the principal receptor for sensing acidosis is unclear, but several receptors have been proposed. We investigated the contribution of the acid-sensing ion channels, transient receptor potential vanilloid type 1 (TRPV1) and transient receptor potential ankyrin type 1 (TRPA1) to peripheral pain signaling. We first established a human pain model using intraepidermal injection of the TRPA1 agonist carvacrol. This resulted in concentration-dependent pain sensations, which were reduced by experimental TRPA1 antagonist A-967079. Capsaicin-induced pain was reduced by the TRPV1 inhibitor BCTC. Amiloride was used to block acid-sensing ion channels. Testing these antagonists in a double-blind and randomized experiment, we probed the contribution of the respective channels to experimental acidosis-induced pain in 15 healthy human subjects. A continuous intraepidermal injection of pH 4.3 was used to counter the buffering capacity of tissue and generate a prolonged painful stimulation. In this model, addition of A-967079, BCTC or amiloride did not reduce the reported pain. In conclusion, target-validated antagonists, applied locally in human skin, have excluded the main hypothesized targets and the mechanism of the human acidosis-induced pain remains unclear. PERSPECTIVE: An acidic milieu is a trigger of pain in many clinical conditions. The aim of this study was to identify the contribution of the currently hypothesized sensors of acid-induced pain in humans. Surprisingly, inhibition of these receptors did not alter acidosis-induced pain.

An Evidence-based Approach to the Medical Management of Fibroids: A Systematic Review.

Fibroids are the most common tumor of the female reproductive tract, but approved medical treatments are limited. Patients demand uterine-sparing treatments which preserve fertility and avoid surgery. We systematically reviewed PubMed and Cochrane databases from January 1985 to November 2015 for evidence-based medical therapies for fibroids in the context of disease prevention, treatment of early disease, treatment of symptomatic disease, and preoperative management. We identified 2182 studies, of which 52 studies met inclusion and exclusion criteria. Published data affirm the efficacy of multiple agents, which are promising avenues for the development of medical alternatives to surgery.

B-Raf Inhibition in the Clinic: Present and Future.

Somatic activating mutations in the B-Raf kinase (BRAF mutations) are present in hairy-cell leukemia, cutaneous melanoma, thyroid carcinomas and, less commonly, in ovarian, colon, lung, and other malignancies. These mutations-in particular the most common substitution, V600E-are oncogenic drivers and important therapeutic targets. The development of small-molecule Raf inhibitors allowed rapid translation of basic advances to the clinic. In BRAF-mutant melanomas, orally bioavailable B-Raf inhibitors, such as vemurafenib, achieve dramatic responses initially, but this is followed by rapid emergence of resistance driven by numerous mechanisms and requiring second-generation treatment approaches. In tumors with wild-type B-Raf, vemurafenib paradoxically activates downstream signaling and cell proliferation and is thus contraindicated, highlighting again the importance of genotype-based clinical decision making. These advances were greatly facilitated by the study of biopsied tumor tissue, especially at the time of drug resistance. Combinatorial approaches targeting the Raf pathway hold promise for even more substantial clinical benefits in the future.

Pharmacological treatment of organophosphorus insecticide poisoning: the old and the (possible) new.

Despite being a major clinical and public health problem across the developing world, responsible for at least 5 million deaths over the last three decades, the clinical care of patients with organophosphorus (OP) insecticide poisoning has little improved over the last six decades. We are still using the same two antidotes - atropine and oximes - that first came into clinical use in the late 1950s. Clinical research in South Asia has shown how improved regimens of atropine can prevent deaths. However, we are still unsure about which patients are most likely to benefit from the use of oximes. Supplemental antidotes, such as magnesium, clonidine and sodium bicarbonate, have all been proposed and studied in small trials without production of definitive answers. Novel antidotes such as nicotinic receptor antagonists, beta-adrenergic agonists and lipid emulsions are being studied in large animal models and in pilot clinical trials. Hopefully, one or more of these affordable and already licensed antidotes will find their place in routine clinical care. However, the large number of chemically diverse OP insecticides, the varied poisoning they produce and their varied response to treatment might ultimately make it difficult to determine definitively whether these antidotes are truly effective. In addition, the toxicity of the varied solvents and surfactants formulated with the OP active ingredients complicates both treatment and studies. It is possible that the only effective way to reduce deaths from OP insecticide poisoning will be a steady reduction in their agricultural use worldwide.

Hairy cell leukemia: update and current therapeutic approach.

PURPOSE OF REVIEW: In this review, we discuss the pathogenesis and standard therapeutic approach to hairy cell leukaemia (HCL) as well as newer targeted therapies under investigation showing promising end-points in treating HCL. RECENT FINDINGS: HCL is an indolent B-cell leukaemia. Historically, HCL patients have achieved excellent response to purine nucleoside analogues and single purine analogue treatment with pentostatin or cladribine is currently the standard of care for initial treatment. Most patients achieve complete remission with this form of therapy. However, long-term follow-up has demonstrated that a large number of patients eventually develop relapsed disease. Relapse disease tends to be more difficult to treat and refractory to the same purine analogues. Development of relapsing and refractory disease after initially achieving complete remission with purine analogue treatment has generated a need for alternative therapies. SUMMARY: Identification of the BRAFV600E mutation in nearly 100% of HCL patients has provided rationale for inclusion of BRAF inhibitors into the therapeutic armamentarium to treat HCL. Clinical trials are currently underway measuring efficacy of vemurafenib in achieving clinical response in relapsed/refractory HCL and also toxicity. Other novel therapies with monoclonal and immunotoxin-conjugated antibodies have also shown promising response in recent investigational studies.

Redifferentiation of iodine-refractory BRAF V600E-mutant metastatic papillary thyroid cancer with dabrafenib.

PURPOSE: To determine whether the selective BRAF inhibitor, dabrafenib, can stimulate radioiodine uptake in BRAF V600E-mutated unresectable or metastatic iodine-refractory papillary thyroid cancer (PTC). EXPERIMENTAL DESIGN: Ten patients with BRAF V600E-mutant iodine-refractory PTC were enrolled. Absence of radioiodine uptake on iodine-131 whole body scan obtained within 14 months of study entry was required. Each patient received dabrafenib (150 mg twice daily) for 25 days before thyrotropin α-stimulated iodine-131 whole body scan (4 mCi/148 MBq). Patients whose scan showed new sites of radioiodine uptake remained on dabrafenib for 17 more days, and then were treated with 150 mCi (5.5 GBq) iodine-131. The primary endpoint of the study was the percentage of patients with new radioiodine uptake after treatment with dabrafenib. RESULTS: Six of 10 patients (60%) demonstrated new radioiodine uptake on whole body scan after treatment with dabrafenib. All 6 were treated with 5.5 GBq iodine-131. Two patients had partial responses and 4 patients had stable disease on standard radiographic restaging at 3 months. Thyroglobulin decreased in 4 of 6 treated patients. One patient developed squamous cell carcinoma of the skin. There were no other significant adverse events attributed to dabrafenib. CONCLUSIONS: Dabrafenib can stimulate radioiodine uptake in patients with metastatic BRAF V600E-mutant iodine-refractory PTC, representing a potential new therapeutic approach for these patients.

Overcoming resistance to BRAF inhibition in BRAF-mutated metastatic melanoma.

Almost 50% of metastatic melanoma patients harbor a BRAF(V600) mutation and the introduction of BRAF inhibitors has improved their treatment options. BRAF inhibitors vemurafenib and dabrafenib achieved improved overall survival over chemotherapy and have been approved for the treatment of BRAF-mutated metastatic melanoma. However, most patients develop mechanisms of acquired resistance and about 15% of them do not achieve tumor regression at all, due to intrinsic resistance to therapy. Moreover, early adaptive responses limit the initial efficacy of BRAF inhibition, leading mostly to incomplete responses that may favor the selection of a sub-population of resistant clones and the acquisition of alterations that cause tumor regrowth and progressive disease. The purpose of this paper is to review the mechanisms of resistance to therapy with BRAF inhibitors and to discuss the strategies to overcome them based on pre-clinical and clinical evidences.