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"Oxazines - pharmacology"
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The BACE‐1 inhibitor CNP520 for prevention trials in Alzheimer's disease
by
Kolly, Carine
,
Veenstra, Siem J
,
Avrameas, Alexandre
in
Alzheimer Disease - blood
,
Alzheimer Disease - cerebrospinal fluid
,
Alzheimer Disease - drug therapy
2018
The beta‐site amyloid precursor protein cleaving enzyme‐1 (BACE‐1) initiates the generation of amyloid‐β (Aβ), and the amyloid cascade leading to amyloid plaque deposition, neurodegeneration, and dementia in Alzheimer's disease (AD). Clinical failures of anti‐Aβ therapies in dementia stages suggest that treatment has to start in the early, asymptomatic disease states. The BACE‐1 inhibitor CNP520 has a selectivity, pharmacodynamics, and distribution profile suitable for AD prevention studies. CNP520 reduced brain and cerebrospinal fluid (CSF) Aβ in rats and dogs, and Aβ plaque deposition in APP‐transgenic mice. Animal toxicology studies of CNP520 demonstrated sufficient safety margins, with no signs of hair depigmentation, retina degeneration, liver toxicity, or cardiovascular effects. In healthy adults ≥ 60 years old, treatment with CNP520 was safe and well tolerated and resulted in robust and dose‐dependent Aβ reduction in the cerebrospinal fluid. Thus, long‐term, pivotal studies with CNP520 have been initiated in the Generation Program.
Synopsis
Alzheimer's disease (AD) is a chronic neurodegenerative disorder with increasing incidence in the aging societies, but without any disease‐modifying treatment. Deposition of toxic forms of the protein Aβ in the brain is pathologic. Treatment with a BACE‐1 inhibitor may prevent Aβ deposition.
Recent BACE inhibitor clinical trials in patients at early or mild‐to‐moderate disease stage have failed, indicating that treatment needs to start earlier, before the onset of clinical symptoms.
BACE inhibitor CNP520 was designed to meet the requirements of prevention treatment.
CNP520 in preclinical models showed acute and chronic Aβ reduction, and a favorable safety profile.
CNP520 is safe and well tolerated in humans, and dose‐dependently reduced Aβ in cerebrospinal fluid.
Prevention studies Generation I and II are underway in patients at enhanced risk to develop symptoms of AD.
Graphical Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disorder with increasing incidence in the aging societies, but without any disease‐modifying treatment. Deposition of toxic forms of the protein Aβ in the brain is pathologic. Treatment with a BACE‐1 inhibitor may prevent Aβ deposition.
Journal Article
Local and global effects of sedation in resting-state fMRI: a randomized, placebo-controlled comparison between etifoxine and alprazolam
by
Schwarzbach, Jens V.
,
Brunner, Lisa-Marie
,
Wagner, Viola
in
Adult
,
Alprazolam - administration & dosage
,
Alprazolam - pharmacology
2024
TSPO ligands are promising alternatives to benzodiazepines in the treatment of anxiety, as they display less pronounced side effects such as sedation, cognitive impairment, tolerance development and abuse potential. In a randomized double-blind repeated-measures study we compare a benzodiazepine (alprazolam) to a TSPO ligand (etifoxine) by assessing side effects and acquiring resting-state fMRI data from 34 healthy participants after 5 days of taking alprazolam, etifoxine or a placebo. To study the effects of the pharmacological interventions in fMRI in detail and across different scales, we combine in our study complementary analysis strategies related to whole-brain functional network connectivity, local connectivity analysis expressed in regional homogeneity, fluctuations in low-frequency BOLD amplitudes and coherency of independent resting-state networks. Participants reported considerable adverse effects such as fatigue, sleepiness and concentration impairments, related to the administration of alprazolam compared to placebo. In resting-state fMRI we found a significant decrease in functional connection density, network efficiency and a decrease in the networks rich-club coefficient related to alprazolam. While observing a general decrease in regional homogeneity in high-level brain networks in the alprazolam condition, we simultaneously could detect an increase in regional homogeneity and resting-state network coherence in low-level sensory regions. Further we found a general increase in the low-frequency compartment of the BOLD signal. In the etifoxine condition, participants did not report any significant side effects compared to the placebo, and we did not observe any corresponding modulations in our fMRI metrics. Our results are consistent with the idea that sedation globally disconnects low-level functional networks, but simultaneously increases their within-connectivity. Further, our results point towards the potential of TSPO ligands in the treatment of anxiety and depression.
Journal Article
Nevirapine and Efavirenz Elicit Different Changes in Lipid Profiles in Antiretroviral- Therapy-Naive Patients Infected with HIV-1
by
Phanuphak, Prahpan
,
Reiss, Peter
,
Schechter, Mauro
in
Adult
,
Anti-HIV Agents - pharmacology
,
Anti-HIV Agents - therapeutic use
2004
Patients infected with HIV-1 initiating antiretroviral therapy (ART) containing a non-nucleoside reverse transcriptase inhibitor (NNRTI) show presumably fewer atherogenic lipid changes than those initiating most ARTs containing a protease inhibitor. We analysed whether lipid changes differed between the two most commonly used NNRTIs, nevirapine (NVP) and efavirenz (EFV).
Prospective analysis of lipids and lipoproteins was performed in patients enrolled in the NVP and EFV treatment groups of the 2NN study who remained on allocated treatment during 48 wk of follow-up. Patients were allocated to NVP (n = 417), or EFV (n = 289) in combination with stavudine and lamivudine. The primary endpoint was percentage change over 48 wk in high-density lipoprotein cholesterol (HDL-c), total cholesterol (TC), TC:HDL-c ratio, non-HDL-c, low-density lipoprotein cholesterol, and triglycerides. The increase of HDL-c was significantly larger for patients receiving NVP (42.5%) than for patients receiving EFV (33.7%; p = 0.036), while the increase in TC was lower (26.9% and 31.1%, respectively; p = 0.073), resulting in a decrease of the TC:HDL-c ratio for patients receiving NVP (-4.1%) and an increase for patients receiving EFV (+5.9%; p < 0.001). The increase of non-HDL-c was smaller for patients receiving NVP (24.7%) than for patients receiving EFV (33.6%; p = 0.007), as were the increases of triglycerides (20.1% and 49.0%, respectively; p < 0.001) and low-density lipoprotein cholesterol (35.0% and 40.0%, respectively; p = 0.378). These differences remained, or even increased, after adjusting for changes in HIV-1 RNA and CD4+ cell levels, indicating an effect of the drugs on lipids over and above that which may be explained by suppression of HIV-1 infection. The increases in HDL-c were of the same order of magnitude as those seen with the use of the investigational HDL-c-increasing drugs.
NVP-containing ART shows larger increases in HDL-c and decreases in TC:HDL-c ratio than an EFV-containing regimen. Based on these findings, protease-inhibitor-sparing regimens based on non-nucleoside reverse transcriptase inhibitor, particularly those containing NVP, may be expected to result in a reduced risk of coronary heart disease.
Journal Article
Role of Spleen Tyrosine Kinase Inhibitors in the Management of Rheumatoid Arthritis
by
Scott, David L.
in
Animals
,
Antirheumatic Agents - adverse effects
,
Antirheumatic Agents - pharmacology
2011
Spleen tyrosine kinase (Syk) is a cytoplasmic tyrosine kinase involved in signalling in many of the cells that drive immune inflammation. The development of small molecules that inhibit Syk kinase may change the way we treat disorders such as rheumatoid arthritis (RA), as well as a range of other inflammatory diseases.
Fostamatinib (R-788) is an orally bioavailable small molecule. It is the prodrug of R406, which is a potent Syk inhibitor. Fostamatinib was developed because it has more favourable physiochemical properties. It is rapidly converted to R406 by intestinal enterocytes. It has been evaluated in experimental models of RA, such as collagen-induced arthritis. In these models, fostamatinib suppressed clinical arthritis, bone erosions, pannus formation and synovitis.
A phase II programme with fostamatinib has largely been completed. Three key trials have been published, lasting 12–26 weeks and each enrolling 189–457 patients (875 in total). All these trials involved placebo therapy and patients continued to receive methotrexate in addition to active treatment with fostamatinib. The first dose-ranging trial evaluated three treatment doses in RA patients who had not fully responded to methotrexate therapy. The second trial compared two treatment doses in patients who had not responded to methotrexate therapy. The third trial compared a single treatment dose with placebo in patients who had not responded to biological therapy.
The primary outcome measure was the number of patients achieving American College of Rheumatology (ACR) 20% (ACR20) responses. Placebo ACR20 response rates in all three trials were similar (35–38%). All three trials involved one treatment arm receiving fostamatinib 100mg twice daily; ACR20 responses with this active treatment ranged from 38% to 67%. A meta-analysis of ACR responses in these trials, using responses to the highest dose in each trial for comparisons with placebo therapy in a random effects model, showed a borderline benefit with ACR20 responses. There were more significant differences with ACR50 and ACR70 responses. The reason that this meta-analysis was not more strongly positive is that the third trial, which evaluated patients who had failed to respond to biological treatments, gave negative results.
Individual ACR response components, such as changes in swollen joint counts, showed significant differences in the first two trials, but there were no definite treatment benefits in the third trial. Overall, the differences were significant in a meta-analysis of all three trials.
The most important adverse reactions were diarrhoea, neutropenia and raised ALT levels, which all showed significant excesses with active treatment compared with placebo. Too few patients have been studied for a definitive safety profile to be known.
Overall, the results of the phase II trials were sufficiently encouraging for a phase III programme to be initiated. It will be some years before their definitive results are available.
Journal Article
Treatment-Emergent Influenza Variant Viruses With Reduced Baloxavir Susceptibility
by
Kawaguchi, Keiko
,
Portsmouth, Simon
,
Hurt, Aeron C.
in
Amino acids
,
Antiviral drugs
,
Clinical trials
2020
Abstract
Background
Single-dose baloxavir rapidly reduces influenza virus titers and symptoms in patients with uncomplicated influenza, but viruses with reduced in vitro susceptibility due to amino acid substitutions at position 38 of polymerase acidic protein (PA/I38X) sometimes emerge.
Methods
We evaluated the kinetics, risk factors, and effects on clinical and virologic outcomes of emergence of PA/I38X-substituted viruses.
Results
Viruses containing PA/I38X substitutions were identified 3–9 days after baloxavir treatment in 9.7% (36/370) of patients, of whom 85.3% had transient virus titer rises. Median time to sustained cessation of infectious virus detection was 192, 48, and 96 hours in the baloxavir recipients with PA/I38X-substituted viruses, without PA/I38X-substituted viruses, and placebo recipients, respectively. The corresponding median times to alleviation of symptoms were 63.1, 51.0, and 80.2 hours, respectively. After day 5, symptom increases occurred in 11.5%, 8.0%, and 13.0%, respectively, and in 8.9% of oseltamivir recipients. Variant virus emergence was associated with lower baseline neutralizing antibody titers.
Conclusions
The emergence of viruses with PA/I38X substitutions following baloxavir treatment was associated with transient rises in infectious virus titers, prolongation of virus detectability, initial delay in symptom alleviation, and uncommonly with symptom rebound. The potential transmissibility of PA/I38X-substituted viruses requires careful study.
Clinical Trial Registration
NCT02954354.
The emergence of PA/I38X-substituted viruses following baloxavir treatment was associated with transient rises in infectious virus titers, prolongation of virus detectability, initial delay in symptom alleviation, and uncommonly with symptom rebound
Journal Article
Bees prefer foods containing neonicotinoid pesticides
by
Simcock, Kerry L.
,
Softley, Samantha
,
Tiedeken, Erin Jo
in
631/378/2626/2627
,
631/601/1466
,
704/158/2456
2015
It has been suggested that the negative effects on bees of neonicotinoid pesticides could be averted in field conditions if they chose not to forage on treated nectar; here field-level neonicotinoid doses are used in laboratory experiments to show that honeybees and bumblebees do not avoid neonicotinoid-treated food and instead actually prefer it.
Bees' responses to neonicotinoids examined
Reports that neonicotinoid insecticides have adverse effects on bee populations remain controversial. Some studies have been criticized as using unrealistically high insecticide dosages or conditions far removed from those in the field, and it has been suggested that bees might be able to detect the insecticides and avoid treated crops. Two papers in this issue of
Nature
present results that fill some of the gaps in our knowledge. In laboratory experiments Sébastien Kessler
et al
. use field-level doses of three commonly used neonicotinoids — clothianidin, imidacloprid and thiamethoxam — to show that both honeybees and bumblebees are able to detect their presence. However, the bees do not avoid neonicotinoid-treated food and may even prefer it. Maj Rundlöf
et al
. sowed oilseed rape with and without a clothianidin seed coating in matched and replicated agricultural landscapes. They found the seed coating to be associated with reduced density of wild bees, as well as reduced nesting of solitary bees and reduced colony growth of bumblebees, but they did not detect an effect on honeybees.
The impact of neonicotinoid insecticides on insect pollinators is highly controversial. Sublethal concentrations alter the behaviour of social bees and reduce survival of entire colonies
1
,
2
,
3
. However, critics argue that the reported negative effects only arise from neonicotinoid concentrations that are greater than those found in the nectar and pollen of pesticide-treated plants
4
. Furthermore, it has been suggested that bees could choose to forage on other available flowers and hence avoid or dilute exposure
4
,
5
. Here, using a two-choice feeding assay, we show that the honeybee,
Apis mellifera
, and the buff-tailed bumblebee,
Bombus terrestris
, do not avoid nectar-relevant concentrations of three of the most commonly used neonicotinoids, imidacloprid (IMD), thiamethoxam (TMX), and clothianidin (CLO), in food. Moreover, bees of both species prefer to eat more of sucrose solutions laced with IMD or TMX than sucrose alone. Stimulation with IMD, TMX and CLO neither elicited spiking responses from gustatory neurons in the bees’ mouthparts, nor inhibited the responses of sucrose-sensitive neurons. Our data indicate that bees cannot taste neonicotinoids and are not repelled by them. Instead, bees preferred solutions containing IMD or TMX, even though the consumption of these pesticides caused them to eat less food overall. This work shows that bees cannot control their exposure to neonicotinoids in food and implies that treating flowering crops with IMD and TMX presents a sizeable hazard to foraging bees.
Journal Article
Fostamatinib: First Global Approval
2018
Rigel Pharmaceuticals are developing the spleen tyrosine kinase (SYK) inhibitor fostamatinib (TAVALISSE™) as a treatment for immune thrombocytopenia (ITP), autoimmune haemolytic anaemia and IgA nephropathy. Based on positive results in the phase III FIT clinical trial program, the drug was recently approved in the US as a treatment for thrombocytopenia in adult patients with chronic ITP who have had an insufficient response to a previous treatment. This article summarizes the milestones in the development of fostamatinib leading to this first approval.
Journal Article
Design, synthesis of benzimidazole tethered 3,4-dihydro-2H-benzoe 1, 3 oxazines as anticancer agents
2024
A series of novel 3-(1H-benzo[d]imidazol-2-yl)-3,4-dihydro-2H-benzo[e][1,3] oxazine analogues synthesized through a two-step synthetic protocol. The structure of the compounds were established by interpretation 1H NMR, 13C NMR and Mass spectral data recorded after purification. All the title compounds 4a–k were screened for their in vitro anti-cancer activity against two breast cancer cell lines MCF 7 and MDA-MB-231 by using Doxorubicin as standard reference. Compound 4e displayed superior activity against both the cell lines MCF-7 and MDA-MB-231 with IC50 values of 8.60 ± 0.75 and 6.30 ± 0.54 µM respectively, compared to the Doxorubicin IC50 value of 9.11 ± 0.54 and 8.47 ± 0.47 µM. Compound 4i also indicated good activity with IC50 value of 9.85 ± 0.69 μM on par with Doxorubicin against MCF-7 cells. Compound 4g demonstrated best activity on par with standard reference to IC50 value of 8.52 ± 0.62 μM against MDA-MB-231 cell line. And all other compounds demonstrated good to moderate activity compared to Doxorubicin. Docking studies against EGFR showed that all the compounds have very good binding affinities towards the target. The predicted drug-likeness properties of all compounds enable them to be used as therapeutic agents.
Journal Article
Predictors of Residual Viremia in HIV-Infected Patients Successfully Treated with Efavirenz and Lamivudine plus either Tenofovir or Stavudine
by
Strain, Matthew C.
,
Ignacio, Caroline C.
,
Koelsch, Kersten K.
in
Adenine - analogs & derivatives
,
Adenine - pharmacology
,
Adenine - therapeutic use
2005
In human immunodeficiency virus (HIV)–infected patients successfully treated with highly active antiretroviral therapy (HAART), a low level of HIV RNA persists in plasma at steady state for years and varies among patients. To understand predictors of residual viremia, we measured HIV RNA levels <50 copies/mL in patients after 1 year of treatment with efavirenz and lamivudine plus either tenofovir disoproxil fumarate (n=55) or stavudine (n=45), by use of an HIV RNA assay with a limit of detection of 2.5 copies/mL. The mean posttreatment HIV RNA levels were 0.58 log10 copies/mL (3.8 copies/mL) in the tenofovir arm and 0.61 log10copies/mL (4.1 copies/mL) in the stavudine arm (P=.24). Forty-seven percent of patients receiving tenofovir, compared with 29% of patients receiving stavudine, had undetectable residual viremia (P=.07). In multivariate analyses, we found that lower baseline HIV RNA levels in plasma, lower HIV DNA levels in peripheral blood mononuclear cells, and inclusion in the tenofovir arm each independently predicted undetectable residual viremia (P<.05). However, a level of residual viremia <50 copies/mL was not associated with CD4 cell count changes or risk of virologic rebound through 72 weeks of follow-up
Journal Article
Genome-wide CRISPR screen identifies host dependency factors for influenza A virus infection
by
Doench, John G.
,
Lingwood, Daniel
,
Gutmann, Michael U.
in
49/47
,
631/326/4041/3196
,
631/326/596/1578
2020
Host dependency factors that are required for influenza A virus infection may serve as therapeutic targets as the virus is less likely to bypass them under drug-mediated selection pressure. Previous attempts to identify host factors have produced largely divergent results, with few overlapping hits across different studies. Here, we perform a genome-wide CRISPR/Cas9 screen and devise a new approach, meta-analysis by information content (MAIC) to systematically combine our results with prior evidence for influenza host factors. MAIC out-performs other meta-analysis methods when using our CRISPR screen as validation data. We validate the host factors,
WDR7, CCDC115
and
TMEM199
, demonstrating that these genes are essential for viral entry and regulation of V-type ATPase assembly. We also find that
CMTR1
, a human mRNA cap methyltransferase, is required for efficient viral cap snatching and regulation of a cell autonomous immune response, and provides synergistic protection with the influenza endonuclease inhibitor Xofluza.
Here, Li et al. perform a genome-wide CRISPR screen to identify host dependency factors for influenza A virus infection and show that the host mRNA cap methyltransferase CMTR1 is important for viral cap snatching and that it affects expression of antiviral genes.
Journal Article