Isoindolinone compounds active as Kv1.5 blockers identified using a multicomponent reaction approach.

A series of isoindolinone compounds have been developed showing good in vitro potency on the Kv1.5 ion channel. By modification of two side chains on the isoindolinone scaffold, metabolically stable compounds with good in vivo PK profile could be obtained leaving the core structure unsubstituted. In this way, low microsomal intrinsic clearance (CLint) could be achieved despite a relatively high logD. The compounds were synthesized using the Ugi reaction, in some cases followed by Suzuki and Diels-Alder reactions, giving a diverse set of compounds in a small number of reaction steps.

Lactam sulfonamides as potent inhibitors of the Kv1.5 potassium ion channel.

A series of lactam sulfonamides has been discovered and optimized as inhibitors of the Kv1.5 potassium ion channel for treatment of atrial fibrillation. In vitro structure-activity relationships from lead structure C to optimized structure 3y are described. Compound 3y was evaluated in a rabbit PD-model and was found to selectively prolong the atrial effective refractory period at submicromolar concentrations.

Synthesis and evaluation of diphenylphosphinic amides and diphenylphosphine oxides as inhibitors of Kv1.5.

Diphenylphosphinic amides and diphenylphosphine oxides have been synthesized and tested as inhibitors of the Kv1.5 potassium ion channel as a possible treatment for atrial fibrillation. In vitro structure-activity relationships are discussed and several compounds with Kv1.5 IC(50) values of <0.5 µM were discovered. Selectivity over the ventricular IKs current was monitored and selective compounds were found. Results from a rabbit PD-model are included.

AZD0284, a Potent, Selective, and Orally Bioavailable Inverse Agonist of Retinoic Acid Receptor-Related Orphan Receptor C2.

Inverse agonists of the nuclear receptor RORC2 have been widely pursued as a potential treatment for a variety of autoimmune diseases. We have discovered a novel series of isoindoline-based inverse agonists of the nuclear receptor RORC2, derived from our recently disclosed RORC2 inverse agonist 2. Extensive structure-activity relationship (SAR) studies resulted in AZD0284 (20), which combined potent inhibition of IL-17A secretion from primary human TH17 cells with excellent metabolic stability and good PK in preclinical species. In two preclinical in vivo studies, compound 20 reduced thymocyte numbers in mice and showed dose-dependent reduction of IL-17A containing γδ-T cells and of IL-17A and IL-22 RNA in the imiquimod induced inflammation model. Based on these data and a favorable safety profile, 20 was progressed to phase 1 clinical studies.

Novel thioamide derivatives as neutral CB1 receptor antagonists.

A novel class of cannabinoid-1 (CB1) receptor antagonists for the treatment of obesity is presented. The carboxamide linker in a set of 5,6-diaryl-pyrazine-2-amide derivatives was transformed into the corresponding thioamide, by using a one-pot synthesis. The structural series of thioamides not only showed retained CB1 potency (below 10nM), but also showed improved solubility. In addition, the neutral antagonist 2c significantly reduced body weight in cafeteria diet obese mice.

Discovery of Potent and Orally Bioavailable Inverse Agonists of the Retinoic Acid Receptor-Related Orphan Receptor C2.

The further optimization of a recently disclosed series of inverse agonists of the nuclear receptor RORC2 is described. Investigations into the left-hand side of compound 1, guided by X-ray crystal structures, led to the substitution of the 4-aryl-thiophenyl residue with the hexafluoro-2-phenyl-propan-2-ol moiety. This change resulted in to compound 28, which combined improved drug-like properties with good cell potency and a significantly lower dose, using an early dose to man prediction. Target engagement in vivo was demonstrated in the thymus of mice by a reduction in the number of double positive T cells after oral dosing.

Potent and Orally Bioavailable Inverse Agonists of RORγt Resulting from Structure-Based Design.

Retinoic acid receptor related orphan receptor γt (RORγt), has been identified as the master regulator of TH17-cell function and development, making it an attractive target for the treatment of autoimmune diseases by a small-molecule approach. Herein, we describe our investigations on a series of 4-aryl-thienyl acetamides, which were guided by insights from X-ray cocrystal structures. Efforts in targeting the cofactor-recruitment site from the 4-aryl group on the thiophene led to a series of potent binders with nanomolar activity in a primary human-TH17-cell assay. The observation of a DMSO molecule binding in a subpocket outside the LBD inspired the introduction of an acetamide into the benzylic position of these compounds. Hereby, a hydrogen-bond interaction of the introduced acetamide oxygen with the backbone amide of Glu379 was established. This greatly enhanced the cellular activity of previously weakly cell-active compounds. The best compounds combined potent inhibition of IL-17 release with favorable PK in rodents, with compound 32 representing a promising starting point for future investigations.

Discovery of a Novel Oral Glucocorticoid Receptor Modulator (AZD9567) with Improved Side Effect Profile.

Synthetic glucocorticoids (GC) are essential for the treatment of a broad range of inflammatory diseases. However, their use is limited by target related adverse effects on, e.g., glucose homeostasis and bone metabolism. Starting from a nonsteroidal GR ligand (4) that is a full agonist in reporter gene assays, we exploited key functional triggers within the receptor, generating a range of structurally diverse partial agonists. Of these, only a narrow subset exhibited full anti-inflammatory efficacy and a significantly reduced impact on adverse effect markers in human cell assays compared to prednisolone. This led to the discovery of AZD9567 (15) with excellent in vivo efficacy when dosed orally in a rat model of joint inflammation. Compound 15 is currently being evaluated in clinical trials comparing the efficacy and side effect markers with those of prednisolone.

Structure-Affinity Relationships and Structure-Kinetic Relationships of 1,2-Diarylimidazol-4-carboxamide Derivatives as Human Cannabinoid 1 Receptor Antagonists.

We report on the synthesis and biological evaluation of a series of 1,2-diarylimidazol-4-carboxamide derivatives developed as CB1 receptor antagonists. These were evaluated in a radioligand displacement binding assay, a [35S]GTPγS binding assay, and in a competition association assay that enables the relatively fast kinetic screening of multiple compounds. The compounds show high affinities and a diverse range of kinetic profiles at the CB1 receptor and their structure-kinetic relationships (SKRs) were established. Using the recently resolved hCB1 receptor crystal structures, we also performed a modeling study that sheds light on the crucial interactions for both the affinity and dissociation kinetics of this family of ligands. We provide evidence that, next to affinity, additional knowledge of binding kinetics is useful for selecting new hCB1 receptor antagonists in the early phases of drug discovery.

Benzoxazepines Achieve Potent Suppression of IL-17 Release in Human T-Helper 17 (TH 17) Cells through an Induced-Fit Binding Mode to the Nuclear Receptor RORγ.

RORγt, an isoform of the retinoic acid-related orphan receptor gamma (RORc, RORγ), has been identified as the master regulator of T-helper 17 (TH 17) cell function and development, making it an attractive target for the treatment of autoimmune diseases. Validation for this target comes from antibodies targeting interleukin-17 (IL-17), the signature cytokine produced by TH 17 cells, which have shown impressive results in clinical trials. Through focused screening of our compound collection, we identified a series of N-sulfonylated benzoxazepines, which displayed micromolar affinity for the RORγ ligand-binding domain (LBD) in a radioligand binding assay. Optimization of these initial hits resulted in potent binders, which dose-dependently decreased the ability of the RORγ-LBD to interact with a peptide derived from steroid receptor coactivator 1, and inhibited the release of IL-17 secretion from isolated and cultured human TH 17 cells with nanomolar potency. A cocrystal structure of inverse agonist 15 (2-chloro-6-fluoro-N-(4-{[3-(trifluoromethyl)phenyl]sulfonyl}-2,3,4,5-tetrahydro-1,4-benzoxazepin-7-yl)benzamide) bound to the RORγ-LBD illustrated that both hydrophobic interactions, leading to an induced fit around the substituted benzamide moiety of 15, as well as a hydrogen bond from the amide NH to His479 seemed to be important for the mechanism of action. This structure is compared with the structure of agonist 25 (N-(2-fluorophenyl)-4-[(4-fluorophenyl)sulfonyl]-2,3,4,5-tetrahydro-1,4-benzoxazepin-6-amine ) and structures of other known RORγ modulators.

Microalbuminuria: an index of severity in childhood meningitis.

Urinary albumin excretion (AE) was determined by a sensitive method (below dipstick positive values, 15 to 300 micrograms/minute) in 68 children with meningitis during 48 hours after hospital admission; 51 children had bacterial meningitis (BM) and 17 had aseptic meningitis. AE (results as mean +/- SD) during 0 to 24 hours was higher (P < 0.001) in patients with BM (36 +/- 40 micrograms/minute) than with aseptic meningitis (7 +/- 5 micrograms/minute), albeit no cutoff value distinguished the two conditions accurately. In BM the clinical course (uneventful, intermediate, complicated, fatal) correlated with AE of 0 to 24 hours (r = 0.34, P < 0.05) and AE of 25 to 48 hours (r = 0.63, P < 0.001). Cerebrospinal fluid protein concentration 24 to 36 hours after initiation of treatment correlated with AE of 25 to 48 hours (r = 0.34, P < 0.05). An index obtained by dividing AE by the weight of the child predicted the severity of clinical course more precisely (77% sensitivity, 85% specificity) than AE alone. Hence renal AE is an easily and non-invasively determined acute phase reactant of potential value as an early estimate of severity of BM.

Serial serum C-reactive protein to monitor recovery from acute hematogenous osteomyelitis in children.

Serial C-reactive protein (CRP) and erythrocyte sedimentation rate determinations were compared with clinical course and outcome at 1 to 2 months in 63 children with acute hematogenous osteomyelitis. High CRP values (163 +/- 108 mg/liter) on admission began to descend after the second day of treatment. From the fourth day on higher (P = 0.03 to P = 0.0001) CRP values distinguished a complicated from an uneventful course of acute hematogenous osteomyelitis and the patients symptomatic at follow-up (P = 0.003 to P = 0.0001) from asymptomatic ones. Children who developed extensive radiographic changes had elevated CRP values for a longer time (32 +/- 13 days) than children with typical changes (11 +/- 6 days, P = 0.0001). Erythrocyte sedimentation rates did not identify the type of clinical course but higher values on Days 4 to 7 distinguished children symptomatic at follow-up (P = 0.02) from asymptomatic ones. Monitoring serial CRP values can alert the physician to complications and predict outcome earlier than clinical signs or roentgenograms.

Serum C-reactive protein in childhood meningitis in countries with limited laboratory resources: a Chilean experience.

Quantitative C-reactive protein (CRP) was determined sequentially by nephelometry and photometry from a finger prick serum sample in 67 children with bacterial meningitis (BM) and 16 children with aseptic meningitis (AM). The initial mean CRP value of 180 mg/liter in children with BM differed significantly from the 12 mg/liter found in those with AM (P less than 0.001). In BM a slow descent instead of rapid normalization or a secondary increase in sequential CRP values were early indicators of complications during recovery, such as resistance to the antibiotic. A significant difference in the mean CRP values between uneventful and complicated courses of BM was observed from the fourth day on (P less than 0.001). The measurements obtained with nephelometry correlated reliably with the more widely available photometry (r = 0.99). Easily performed rapid CRP determinations can considerably improve the quality of care in meningitis patients, especially in those situations where facilities for performing bacterial cultures or antibiotic susceptibility testing are not available.

Randomized trial of four vs. seven days of ceftriaxone treatment for bacterial meningitis in children with rapid initial recovery.

BACKGROUND: Seven days or more of antimicrobial treatment is the standard for bacterial meningitis, although third generation cephalosporins are usually able to sterilize cerebrospinal fluid within 24 h. The limited experience from shorter regimens in children is encouraging, and we hypothesized that in rapidly recovering patients older than 3 months of age it would pose no risk for adverse outcome. METHODS: Strict clinical and laboratory criteria were used to define rapid initial recovery, in which case ceftriaxone therapy was either stopped after 4 days (4 injections) in children born on even dates (N = 53) or continued for 7 days in patients born on odd dates (N = 47). Outcomes were compared on Day 7 of hospitalization and at 1 to 3 months after discharge. RESULTS: On Day 7 no differences (P > 0.05 for each criteria) were observed between the 4-day and the 7-day groups regarding fever, clinical signs or serum C-reactive protein concentration. At the follow-up visit 1 to 3 months after discharge the 4-day group had fewer sequelae than the 7-day group (0% vs. 5% neurologic sequelae, P = 0.39 and 3% vs. 9% hearing loss, P = 0.49, respectively). One child in the 4-day group who had fully recovered was subsequently readmitted 53 days after the first hospitalization with recurrent Haemophilus influenzae meningitis. CONCLUSIONS: Four days of ceftriaxone therapy proved to be a safe alternative in patients with rapid initial recovery from bacterial meningitis. A 4-day course of treatment is particularly beneficial for countries with limited resources.

Estudio en el grupo de meningitis bacteriana, influencia de la malnutricion en el curso de niños con meningitis bacteriana / Study group of bacterial meningitis, malnutrition influence the course of children with bacterial meningitis

La meningitis bacteriana sigue siendo un problema importante a nivel mundial, a pesar de la virtual eliminación inducida por la vacuna del Haemophilus influenzae tipo b y en menor medidadel neumococo. Una de las razones de su mal pronóstico en los países en desarrollo es la asociación con bajo peso.

Early detection of sequela-prone osteomyelitis in children with use of simple clinical and laboratory criteria.

To determine which clinical or laboratory criteria best reflected the prognosis for 83 children with acute hematogenous osteomyelitis (AHO), they were compared with outcomes after a follow-up of at least 2 months (for 78%, > or = 6 months). Twenty-eight children (34%) developed sequelae. They had higher serum C-reactive protein (CRP) concentrations (days 1-6 of treatment; P = .0004 to .0001) and higher clinical scores (P = .0001) than did patients who had an uneventful recovery. The frequency of sequelae increased from 3% to 73% (P = .0001) when CRP concentrations exceeded the defined cutoff limits and the clinical scores were > or = 1. Age, the duration of symptoms at diagnosis, and the type and duration of intravenous antimicrobial therapy or surgical management did not differ (P > .05) between children with and without sequelae. Both CRP determinations and clinical evaluations with use of a scoring system enable early detection of sequela-prone AHO in children and are most accurate when used together.

C-reactive protein in measles.

Seventy-two children with early measles (1st-3rd day of rash), presenting at two centres in Santiago, Chile, were classified as having mild ('ordinary measles', n = 50), or moderate to severe measles ('primarily severe measles', n = 22). The level of serum C-reactive protein (CRP) was determined by nephelometry from a finger prick sample. The mean CRP value in ordinary measles, 19 mg/l, was significantly lower (P less than 0.001) than in primarily severe measles where the mean CRP was 65 mg/l. During late measles (5th-8th day of rash), the mean CRP was 19 mg/l if the child recovered uneventfully (n = 35), whereas the mean level of 123 mg/l (P less than 0.001) was encountered when the child suffered from complicating pneumonia (n = 22). We conclude that the simple quantitative CRP determination is a useful alarm signal during the course of measles: elevated levels point to severity or complications in recovery.