Activity of the oral mitogen-activated protein kinase kinase inhibitor trametinib in RAS-mutant relapsed or refractory myeloid malignancies.

BACKGROUND: RAS/RAF/mitogen-activated protein kinase activation is common in myeloid malignancies. Trametinib, a mitogen-activated protein kinase kinase 1 (MEK1)/MEK2 inhibitor with activity against multiple myeloid cell lines at low nanomolar concentrations, was evaluated for safety and clinical activity in patients with relapsed/refractory leukemias. METHODS: This phase 1/2 study accrued patients with any relapsed/refractory leukemia in phase 1. In phase 2, this study accrued patients with relapsed/refractory acute myeloid leukemia (AML) or high-risk myelodysplastic syndromes (MDS) with NRAS or KRAS mutations (cohort 1); patients with AML, MDS, or chronic myelomonocytic leukemia (CMML) with a RAS wild-type mutation or an unknown mutation status (cohort 2); and patients with CMML with an NRAS or KRAS mutation (cohorts 3). RESULTS: The most commonly reported treatment-related adverse events were diarrhea, rash, nausea, and increased alanine aminotransferase levels. The phase 2 recommended dose for Trametinib was 2 mg orally daily. The overall response rates were 20%, 3%, and 27% for cohorts 1, 2, and 3, respectively, and this indicated preferential activity among RAS-mutated myeloid malignancies. Repeated cycles of trametinib were well tolerated with manageable or reversible toxicities; these results were similar to those of other trametinib studies. CONCLUSIONS: The selective, single-agent activity of trametinib against RAS-mutated myeloid malignancies validates its therapeutic potential. Combination strategies based on a better understanding of the hierarchical role of mutations and signaling in myeloid malignancies are likely to improve the response rate and duration. Cancer 2016;122:1871-9. © 2016 American Cancer Society.

The small molecule Retro-1 enhances the pharmacological actions of antisense and splice switching oligonucleotides.

The attainment of strong pharmacological effects with oligonucleotides is hampered by inefficient access of these molecules to their sites of action in the cytosol or nucleus. Attempts to address this problem with lipid or polymeric delivery systems have been only partially successful. Here, we describe a novel alternative approach involving the use of a non-toxic small molecule to enhance the pharmacological effects of oligonucleotides. The compound Retro-1 was discovered in a screen for small molecules that reduce the actions of bacterial toxins and has been shown to block the retrograde trafficking pathway. We demonstrate that Retro-1 can also substantially enhance the effectiveness of antisense and splice switching oligonucleotides in cell culture. This effect occurs at the level of intracellular trafficking or processing and is correlated with increased oligonucleotide accumulation in the nucleus but does not involve the perturbation of lysosomal compartments. We also show that Retro-1 can alter the effectiveness of splice switching oligonucleotides in the in vivo setting. These observations indicate that it is possible to enhance the pharmacological actions of oligonucleotides using non-toxic and non-lysosomotropic small molecule adjuncts.

Concomitant oral and intravenous pharmacokinetics of trametinib, a MEK inhibitor, in subjects with solid tumours.

AIMS: The aim of this phase 1, single centre, open label study in four patients with solid tumours was to determine the absolute bioavailability of a 2 mg oral dose of trametinib. Trametinib is an orally bioavailable, reversible and selective allosteric inhibitor of MEK1 and MEK2 activation and kinase activity. METHODS: A microtracer study approach, in which a 5 µg radiolabelled i.v. microdose of trametinib was given concomitantly with an unlabelled 2 mg oral tablet formulation, was used to recover i.v. and oral pharmacokinetic parameters, simultaneously. RESULTS: The least-squares mean (90% confidence interval) absolute bioavailability of trametinib (2 mg tablet) was 72.3% (50.0%, 104.6%). Median tmax after oral administration was 1.5 h and the geometric mean terminal half-life was 11 days. The geometric mean clearance and volume of distribution after i.v. administration were 3.21 l h(-1) and 976 l, respectively, resulting in a terminal elimination half-life of 11 days. CONCLUSIONS: Trametinib absolute bioavailability was moderate to high, whereas first pass metabolism was low.

Trametinib, a first-in-class oral MEK inhibitor mass balance study with limited enrollment of two male subjects with advanced cancers.

1. This study assessed the mass balance, metabolism and disposition of [(14)C]trametinib, a first-in-class mitogen-activated extracellular signal-related kinase (MEK) inhibitor, as an open-label, single solution dose (2 mg, 2.9 MBq [79 µCi]) in two male subjects with advanced cancer. 2. Trametinib absorption was rapid. Excretion was primarily via feces (∼81% of excreted dose); minor route was urinary (∼19% of excreted dose). The primary metabolic elimination route was deacetylation alone or in combination with hydroxylation. Circulating drug-related component profiles (composed of parent with metabolites) were similar to those found in elimination together with N-glucuronide of deacetylation product. Metabolite analysis was only possible from <50% of administered dose; therefore, percent of excreted dose (defined as fraction of percent of administered dose recovery over total dose recovered in excreta) was used to assess the relative importance of excretion and metabolite routes. The long elimination half-life (∼10 days) favoring sustained targeted activity was important in permitting trametinib to be the first MEK inhibitor with clinical activity in late stage clinical studies. 3. This study exemplifies the challenges and adaptability needed to understand the metabolism and disposition of an anticancer agent, like trametinib, with both low exposure and a long elimination half-life.

Oligonucleotide therapeutics in cancer.

Alterations in pre-mRNA splicing can have profound effects on gene expression and lead to cellular transformation. Oligonucleotide therapeutics are drugs that manipulate gene expression and improve the disease state. Antisense oligonucleotides hybridize with a target mRNA to downregulate gene expression via an RNase H-dependent mechanism. Additionally, RNase H-independent splice switching oligonucleotides (SSO) modulate alternative or aberrant splicing, to favor the therapeutically relevant splicing product. This chapter summarizes the progress made in the application of these oligonucleotide drugs in the treatment of cancer.

Perioperative Lidocaine Infusion Reduces Opioid Use in Enhanced Recovery After Surgery Patients Undergoing Laparoscopic Colectomy.

BACKGROUND: Enhanced Recovery After Surgery (ERAS) programs have become a mainstay of modern surgical care, and efforts to decrease postoperative opioid consumption have been increasingly employed. A previous study from our institution demonstrated that ERAS protocols decreased opioid use in the first 48 hours after surgery by 61%. In the present study, a lidocaine infusion was added for postoperative pain control. The aim was to analyze the differences in opioid requirements with and without this infusion in the first 48 hours after laparoscopic colectomy in ERAS patients. METHODS: Retrospective review of patients was conducted at an academically affiliated tertiary care hospital. The population included patients undergoing elective laparoscopic colon surgery enrolled in the ERAS program with the implementation of a lidocaine drip from June 2019 to October 2019, and compared to a previous patient cohort of ERAS patients evaluated without the lidocaine drip from September 2015 to May 2018. RESULTS: The primary endpoint was postoperative opioid use in the first 48 hours based on IV morphine milligram equivalents (MME). Secondary measures included type of surgery, age, BMI, prior abdominal surgery, and prior opioid use. Median MMEs were 6.0 in the lidocaine infusion group and 12.5 in the group without lidocaine, representing a 52% reduction (p < 0.001). DISCUSSION: This study demonstrates a significant reduction in post-op opioid use in ERAS patients who receive a lidocaine infusion after laparoscopic colectomy. Further studies should focus on measures to limit the treatment side effects in order to maximize the opioid-sparing benefits of this intervention.

Effect of hepatic or renal impairment on the pharmacokinetics of casopitant, a NK-1 receptor antagonist.

Two studies were conducted in subjects with mild or moderate hepatic or renal impairment and subjects with normal organ function to evaluate the pharmacokinetics of casopitant and to assess its safety in these populations. A total of 26 subjects were enrolled in the hepatic impairment study and 18 subjects in the renal impairment study. All subjects received oral casopitant 100 mg once-daily for 5 days. Casopitant area under the concentration-time curve (AUC) increased 11% and 24% in subjects with mild or moderate hepatic impairment, respectively, on Day 1, compared with subjects with normal hepatic function; a similar increase was observed on Day 5. The AUC of the active major metabolite, GSK525060, was reduced 29% and 19% on Days 1 and 5, respectively, in subjects with moderate hepatic impairment, but not altered by mild hepatic impairment. Casopitant AUC increased 34% and 22% on Day 1 in subjects with mild or moderate renal impairment, respectively, and 28% and 11% on Day 5, respectively, compared with subjects with normal renal function. GSK525060 AUC was increased 17% and 24% on Days 1 and 5, respectively, in subjects with mild renal impairment; but did not significantly change in subjects with moderate renal impairment. Further age-adjusted analysis showed no meaningful effect of renal impairment on casopitant or GSK525060 AUC. Plasma protein binding of casopitant and GSK525060 was similar in all subjects. The pharmacokinetics of casopitant is not altered to a clinically significant extent in subjects with mild or moderate, hepatic or renal impairment. The impact of severe hepatic or renal impairment was not evaluated.

Anti-tumor activity of splice-switching oligonucleotides.

Alternative splicing has emerged as an important target for molecular therapies. Splice-switching oligonucleotides (SSOs) modulate alternative splicing by hybridizing to pre-mRNA sequences involved in splicing and blocking access to the transcript by splicing factors. Recently, the efficacy of SSOs has been established in various animal disease models; however, the application of SSOs against cancer targets has been hindered by poor in vivo delivery of antisense therapeutics to tumor cells. The apoptotic regulator Bcl-x is alternatively spliced to express anti-apoptotic Bcl-x(L) and pro-apoptotic Bcl-x(S). Bcl-x(L) is upregulated in many cancers and is associated with chemoresistance, distinguishing it as an important target for cancer therapy. We previously showed that redirection of Bcl-x pre-mRNA splicing from Bcl-x(L) to -x(S) induced apoptosis in breast and prostate cancer cells. In this study, the effect of SSO-induced Bcl-x splice-switching on metastatic melanoma was assessed in cell culture and B16F10 tumor xenografts. SSOs were delivered in vivo using lipid nanoparticles. Administration of nanoparticle with Bcl-x SSO resulted in modification of Bcl-x pre-mRNA splicing in lung metastases and reduced tumor load, while nanoparticle alone or formulated with a control SSO had no effect. Our findings demonstrate in vivo anti-tumor activity of SSOs that modulate Bcl-x pre-mRNA splicing.

Changes in Lake Sturgeon Gut Microbiomes Relative to Founding Origin and in Response to Chemotherapeutant Treatments.

Antibiotics, drugs, and chemicals (collectively referred to as chemotherapeutants) are widely embraced in fish aquaculture as important tools to control or prevent disease outbreaks. Potential negative effects include changes in microbial community composition and diversity during early life stages, which can reverse the beneficial roles of gut microbiota for the maintenance of host physiological processes and homeostatic regulation. We characterized the gut microbial community composition and diversity of an ecologically and economically important fish species, the lake sturgeon (Acipenser fulvescens), during the early larval period in response to weekly treatments using chemotherapeutants commonly used in aquaculture (chloramine-T, hydrogen peroxide, and NaCl2 followed by hydrogen peroxide) relative to untreated controls. The effects of founding microbial community origin (wild stream vs. hatchery water) were also evaluated. Gut communities were quantified using massively parallel next generation sequencing based on the V4 region of the 16S rRNA gene. Members of the phylum Firmicutes (principally unclassified Clostridiales and Clostridium_sensu_stricto) and Proteobacteria were the dominant taxa in all gut samples regardless of treatment. The egg incubation environment (origin) and its interaction with chemotherapeutant treatment were significantly associated with indices of microbial taxonomic diversity. We observed large variation in the beta diversity of lake sturgeon gut microbiota between larvae from eggs incubated in hatchery and wild (stream) origins based on nonmetric dimensional scaling (NMDS). Permutational ANOVA indicated the effects of chemotherapeutic treatments on gut microbial community composition were dependent on the initial source of the founding microbial community. Influences of microbiota colonization during early ontogenetic stages and the resilience of gut microbiota to topical chemotherapeutic treatments are discussed.

Can the American College of Surgeons National Surgical Quality Improvement Program Risk Calculator Predict Outcomes for Urgent Colectomies?

BACKGROUND: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) Risk Calculator (RC) predicts postoperative outcomes using 19 risk factors, including operative acuity. Acuity is defined by the calculator as emergent or elective only. The objective of this study is to evaluate the RC's accuracy in urgent (nonelective/nonemergent) cases. METHODS: This is a retrospective review of the NSQIP data for patients who underwent urgent colectomies at a single tertiary care center over a 4-year period. Each urgent case was entered into the RC as both elective and emergent, and predicted outcomes were compared to actual postoperative outcomes. Receiver operating characteristic (ROC) curves were used when sufficient statistical power was present and the area under the curve (AUC) was calculated. RESULTS: A total of 301 urgent colectomy patients were evaluated, representing 19% of all colectomies performed at our institution during the study period. Of the 15 possible postoperative outcomes, the RC showed high predictive value only for mortality (AUC elective .8467; emergent .8451) and discharge to a nursing/rehabilitation facility (AUC elective .8089; emergent .8105). The RC showed no predictive value for 6 outcomes and the remainder lacked statistical power to draw conclusions. DISCUSSION: While the calculator predicted mortality and discharge to a nursing/rehabilitation facility, it did not accurately predict complications for urgent colectomies. Future versions of the calculator should focus on improving the predictive value by including urgent cases as a separate category.

Compositional Dynamics of Gastrointestinal Tract Microbiomes Associated with Dietary Transition and Feeding Cessation in Lake Sturgeon Larvae.

Compromised nutritional conditions associated with dietary transitions and feeding cessation in the wild and during fish aquaculture operations are common and can impact growth and survival. These effects are especially prevalent during early ontogenetic stages. We quantified phenotypic and GI tract microbial community responses with an emphasis on protease-producing bacteria of lake sturgeon (Acipenser fulvescens) larvae, a species of aquacultural and conservational importance. To quantify responses associated with experimental food transition and feeding cessation, we performed a 36-day feeding experiment using two treatments: control and diet transition. However, larvae in the diet transition treatment failed to undergo transition and ceased feeding. Larvae in the diet transition treatment exhibited lower growth (total length and body weight) and survival than control larvae. Treatment had a greater effect than ontogenetic changes on taxonomic composition and diversity of the GI tract microbial community. Proteobacteria dominated the GI tract microbial community of the diet transition larvae whereas Firmicutes dominated the GI tracts of control larvae. Most of the 98 identified protease-producing isolates in both treatments were from genera Pseudomonas and Aeromonas: taxonomic groups that include known fish pathogens. Overall, failing to transition diets affected responses in growth and GI tract microbiome composition and diversity, with the later dysbiosis being an indicator of morbidity and mortality in larval lake sturgeon. Thus, microbiological interrogations can characterize responses to dietary regimes. The results can inform fish culturalists and microbiologists of the importance of dietary practices consistent with the establishment and maintenance of healthy GI tract microbiota and optimal growth during early ontogeny.

Aquatic insects differentially affect lake sturgeon larval phenotypes and egg surface microbial communities.

Documentation of how interactions among members of different stream communities [e.g., microbial communities and aquatic insect taxa exhibiting different feeding strategies (FS)] collectively influence the growth, survival, and recruitment of stream fishes is limited. Considerable spatial overlap exists between early life stages of stream fishes, including species of conservation concern like lake sturgeon (Acipenser fulvescens), and aquatic insects and microbial taxa that abundantly occupy substrates on which spawning occurs. Habitat overlap suggests that species interactions across trophic levels may be common, but outcomes of these interactions are poorly understood. We conducted an experiment where lake sturgeon eggs were fertilized and incubated in the presence of individuals from one of four aquatic insect FS taxa including predators, facultative and obligate-scrapers, collector-filterers/facultative predators, and a control (no insects). We quantified and compared the effects of different insect taxa on the taxonomic composition and relative abundance of egg surface bacterial and lower eukaryotic communities, egg size, incubation time to hatch, free embryo body size (total length) at hatch, yolk-sac area, (a measure of resource utilization), and percent survival to hatch. Mean egg size varied significantly among insect treatments. Eggs exposed to predators had a lower mean percent survival to hatch. Eggs exposed to predators had significantly shorter incubation periods. At hatch, free embryos exposed to predators had significantly smaller yolk sacs and total length. Multivariate analyses revealed that egg bacterial and lower eukaryotic surface community composition varied significantly among insect treatments and between time periods (1 vs 4 days post-fertilization). Quantitative PCR documented significant differences in bacterial 16S copy number, and thus abundance on egg surfaces varied across insect treatments. Results indicate that lethal and non-lethal effects associated with interactions between lake sturgeon eggs and free embryos and aquatic insects, particularly predators, contributed to lake sturgeon trait variability that may affect population levels of recruitment.

The identification of a small molecule inhibitor that specifically reduces T cell-mediated adaptive but not LPS-mediated innate immunity by T cell membrane-monocyte contact bioassay.

Proinflammatory cytokines such as TNFalpha and IL-1beta are produced in lesional skin of chronic plaque psoriasis patients, and at other sites of chronic inflammation such as arthritic joints. They play vital roles in maintaining inflammation. It has recently been suggested that activated T cell contact-mediated monocyte activation, leading to the production of proinflammatory cytokines, contributes to the pathogenesis of psoriasis and other chronic inflammatory diseases such as psoriatic arthritis and rheumatoid arthritis. Using a T cell membrane-monocyte contact bioassay, we have identified small molecule antagonists that differentially block anti-CD3/anti-CD28 activated T cell-mediated, but not LPS-stimulated, TNFalpha production from monocytes. We selected several kinase inhibitors from the Berlex/Schering kinase library and tested the effect of these compounds in blocking TNFalpha production in the T cell membrane-monocyte contact bioassay. We have demonstrated that one compound BLX-1, from a p38 MAP kinase inhibitor project, inhibited T cell-mediated TNFalpha production from monocytes by about 80%, without any effect on TNFalpha production from LPS-stimulated monocytes. Other BLX-1 analogs showed 32-83% inhibition of TNFalpha production with LPS stimulation as compared to almost 100% inhibition of T cell-mediated TNFalpha production. In contrast, PKC inhibitors BLX-5, Go6983, and Ro-31-8220, inhibited TNFalpha production from both activated T cell membrane- and LPS-stimulated monocytes to the same extent (in the range of 50-100% inhibition). Therefore, the activated T cell membrane-monocyte contact bioassay can be used to screen small molecule antagonists that specifically target adaptive but not LPS-mediated innate immunity. Small molecule TNFalpha inhibitors interfering specifically with activated T cell contact-mediated TNFalpha production from monocytes, but not with LPS-mediated TNFalpha production of myeloid cells, are predicted to have an improved side-effect profile and thus may provide more favorable therapeutics for the treatment of T cell-mediated inflammatory diseases.

Discovery of novel and potent aryl diamines as leukotriene A4 hydrolase inhibitors.

The synthesis and biological evaluation of a series of aryl diamines as inhibitors of LTA(4)-h inhibitors are described. The optimization which led to the identification of the optimal para-substitution on the diphenyl ether moiety and diamine spacer is discussed. The resulting compounds such as 3l have excellent enzyme and cellular potency as well as desirable pharmacokinetic properties.

Synthesis of N-alkyl glycine amides as potent inhibitors of leukotriene A4 hydrolase.

The synthesis and biological evaluation of a series of N-alkyl glycine amide analogs as LTA(4)-h inhibitors and the importance of the introduction of a benzoic acid group to the potency and pharmacokinetic parameters of our analogs are described. The lead compound in the series, 4q, has excellent potency and oral bioavailability.

Synthesis of glutamic acid analogs as potent inhibitors of leukotriene A4 hydrolase.

Leukotriene B(4) (LTB(4)) is a potent pro-inflammatory mediator that has been implicated in the pathogenesis of multiple diseases, including psoriasis, inflammatory bowel disease, multiple sclerosis and asthma. As a method to decrease the level of LTB(4) and possibly identify novel treatments, inhibitors of the LTB(4) biosynthetic enzyme, leukotriene A(4) hydrolase (LTA(4)-h), have been explored. Here we describe the discovery of a potent inhibitor of LTA(4)-h, arylamide of glutamic acid 4f, starting from the corresponding glycinamide 2. Analogs of 4f are then described, focusing on compounds that are both active and stable in whole blood. This effort culminated in the identification of amino alcohol 12a and amino ester 6b which meet these criteria.

Simple hand fractures that aren't.

Patients expect physicians to predict the future. Recognizing injuries that behave badly improves care and modulates expectations. Your antennae should deploy when you are presented with a simple fracture that isn't.

Phase 1 study to evaluate the effect of the MEK inhibitor trametinib on cardiac repolarization in patients with solid tumours.

PURPOSE: Trametinib is a reversible, selective inhibitor of the mitogen-activated extracellular signal-regulated kinase 1 (MEK1) and 2 (MEK2). Cardiotoxicity (congestive heart failure, decreased heart rate, left ventricular dysfunction, and hypertension) related to trametinib is an infrequent, but serious, adverse event (AE). Prolongation of the QT interval increases the risk of life-threatening cardiac arrhythmia. Thus, the risk of trametinib inducing QT prolongation at putative supratherapeutic exposure was evaluated. METHODS: Eligible patients with solid tumours received placebo on day 1, once-daily trametinib 2-mg doses on days 2-14, and a single trametinib 3-mg dose on day 15 to achieve supratherapeutic dosing for QTc measurement. Electrocardiogram was assessed by 12-lead ambulatory 24-h Holter monitoring pre-dose, and on day 1 and day 15. Pharmacokinetic (PK) and pharmacodynamics (PD) parameters were measured. RESULTS: Thirty-two of 35 patients completed the study. There was no effect of trametinib when compared with time-matched placebo on the change from baseline in QTcF, QTcB, or QTcI interval. Mean AUC0-24 and C max following trametinib 2-mg repeat doses were 364 ng.h/mL and 22.9 ng/mL, respectively; the corresponding values for the 3-mg dose were 454 ng.h/mL and 29.2 ng/mL. Median T max was approximately 2 h for both doses. Statistical analysis and PK/PD modelling showed no significant relationship between QTcF interval and trametinib plasma concentrations. AEs were consistent with those reported previously. No electrocardiogram abnormalities were reported as AEs. CONCLUSIONS: The results of this study suggest trametinib has no significant effect on QT prolongation at supratherapeutic exposure.

The outpatient treatment of pyogenic flexor tenosynovitis.

Historically, pyogenic flexor tenosynovitis has been treated with surgical debridement followed by hospitalization and administration of intravenous antibiotics. Recently, hand surgeons have treated this disorder on an outpatient basis. We retrospectively reviewed 37 patients with pyogenic flexor tenosynovitis who were managed as outpatients. Each patient underwent operative irrigation and debridement with intraoperative catheter irrigation. Postoperatively, patients were treated with outpatient intravenous antibiotics. Conversion to oral antibiotics was based on intraoperative culture results. Using this protocol, the average length of intravenous antibiotic usage was 3.5 days. Of the 28 patients with documented follow-up, 27 resolved the infection and one had a recurrence of the infection. No amputations were noted. Total active motion measurement was obtained from 15 patients showing good or excellent results in 14 of 15 patients. This preliminary retrospective case cohort suggests favorable results with outpatient treatment of pyogenic flexor tenosynovitis.

Novel 3-oxa lipoxin A4 analogues with enhanced chemical and metabolic stability have anti-inflammatory activity in vivo.

Lipoxin A(4) (LXA(4)) is a structurally and functionally distinct natural product called an eicosanoid, which displays immunomodulatory and anti-inflammatory activity but is rapidly metabolized to inactive catabolites in vivo. A previously described analogue of LXA(4), methyl (5R,6R,7E,9E,11Z,13E,15S)-16-(4-fluorophenoxy)-5,6,15-trihydroxy-7,9,11,13-hexadecatetraenoate (2, ATLa), was shown to have a poor pharmacokinetic profile after both oral and intravenous administration, as well as sensitivity to acid and light. The chemical stability of the corresponding E,E,E-trien-11-yne analogue, 3, was improved over 2 without loss of efficacy in the mouse air pouch model of inflammation. Careful analysis of the plasma samples from the pharmacokinetic assays for both 2 and 3 identified a previously undetected metabolite, which is consistent with metabolism by beta-oxidation. The formation of the oxidative metabolites was eliminated with the corresponding 3-oxatetraene, 4, and the 3-oxatrien-11-yne, 5, analogues of 2. Evaluation of 3-oxa analogues 4 and 5 in calcium ionophore-induced acute skin inflammation model demonstrated similar topical potency and efficacy compared to 2. The 3-oxatrien-11-yne analogue, 5, is equipotent to 2 in an animal model of inflammation but has enhanced metabolic and chemical stability and a greatly improved pharmacokinetic profile.