Evidence for effect of l-serine, a novel therapy for GRIN2B-related neurodevelopmental disorder

RATIONALE

To date, causal therapy is potentially available for GRIN2B-related neurodevelopmental disorder (NDD) due to loss-of-function (LoF) variants in GRIN2B, resulting in dysfunction of the GluN2B subunit-containing N-methyl-d-aspartate receptor (NMDAR). Recently, in vitro experiments showed that high doses of NMDAR co-agonist d-serine has the potential to boost the activity in GluN2B LoF variant-containing NMDARs. Initial reports of GRIN2B-NDD patients LoF variants, treated with l-serine using different regimens, showed varying effects on motor and cognitive performance, communication, behavior and EEG. Here, this novel treatment using a standardized protocol with an innovative developmental outcome measure is explored further in an open-label observational GRIN2B-NDD study.

METHODS

Initially, in vitro studies were conducted in order to functionally stratify two de novo GRIN2B variants present in two female patients (18 months and 4 years old). Functional studies showed that both variants are LoF, and thus the patients were treated experimentally according to an approved protocol with oral l-serine (500 mg/kg/day in 4 doses) for a period of 12 months. Both patients showed a heterogeneous clinical phenotype, however overlapping symptoms were present: intellectual developmental disability (IDD), behavioral abnormalities and hypotonia. Outcome measures included laboratory tests, quality of life, sleep, irritability, stool, and performance skills, measured by, among others, the Perceive-Recall-Plan-Perform System of Task Analysis (PRPP-Assessment).

RESULTS

Both patients tolerated l-serine without adverse effects. In one patient, improvement in psychomotor development and cognitive functioning was observed after 12 months (PRPP mastery score 10% at baseline, 78% at twelve months). In the most severe clinically affected patient no significant objective improvement in validated outcomes was observed. Caregivers of both patients reported subjective increase of alertness and improved communication skills.

CONCLUSION

Our observational study confirms that l-serine supplementation is safe in patients with GRIN2B-NDD associated with LoF variants, and may accelerate psychomotor development and ameliorate cognitive performance in some but not all patients. The PRPP-Assessment, a promising instrument to evaluate everyday activities and enhance personalized and value-based care, was not performed in the severely affected patient, meaning that possible positive results may have been missed. To generate stronger evidence for effect of l-serine in GRIN2B-NDD, we will perform placebo-controlled n-of-1 trials.

Cohort profile: the ESC EURObservational Research Programme Non-ST-segment elevation myocardial infraction (NSTEMI) Registry

AIMS

The European Society of Cardiology (ESC) EURObservational Research Programme (EORP) Non-ST-segment elevation myocardial infarction (NSTEMI) Registry aims to identify international patterns in NSTEMI management in clinical practice and outcomes against the 2015 ESC Guidelines for the management of acute coronary syndromes in patients presenting without ST-segment-elevation.

METHODS AND RESULTS

Consecutively hospitalised adult NSTEMI patients (n = 3620) were enrolled between 11 March 2019 and 6 March 2021, and individual patient data prospectively collected at 287 centres in 59 participating countries during a two-week enrolment period per centre. The registry collected data relating to baseline characteristics, major outcomes (in-hospital death, acute heart failure, cardiogenic shock, bleeding, stroke/transient ischaemic attack, and 30-day mortality) and guideline-recommended NSTEMI care interventions: electrocardiogram pre- or in-hospital, pre-hospitalization receipt of aspirin, echocardiography, coronary angiography, referral to cardiac rehabilitation, smoking cessation advice, dietary advice, and prescription on discharge of aspirin, P2Y12 inhibition, angiotensin converting enzyme inhibitor (ACEi)/angiotensin receptor blocker (ARB), beta-blocker, and statin.

CONCLUSION

The EORP NSTEMI Registry is an international, prospective registry of care and outcomes of patients treated for NSTEMI, which will provide unique insights into the contemporary management of hospitalised NSTEMI patients, compliance with ESC 2015 NSTEMI Guidelines, and identify potential barriers to optimal management of this common clinical presentation associated with significant morbidity and mortality.

MINIMALLY INVASIVE TREATMENT OF ABDOMINAL LYMPHOCELE: A REVIEW OF CONTEMPORARY OPTIONS AND HOW TO APPROACH THEM

Lymphoceles are lymphatic fluid collections resulting from lymphatic vessel disruption after surgery or trauma. They are most often described following retroperitoneal surgeries such as cystectomies, prostatectomies, renal transplants, and gynecologic surgeries. Most lymphoceles are asymptomatic and resolve spontaneously without treatment. If persistent, they can become infected or exert mass effect on adjacent structures causing pain, urinary, or lower limb edema particularly for lymphoceles in the pelvis Symptomatic lymphoceles should be treated to relieve symptoms and prevent functional compromise of vital adjacent structures. Although surgery has been traditionally accepted as the gold standard treatment, advances in imaging and interventional technology allow for less invasive, percutaneous treatment. Available minimally invasive treatment options include percutaneous aspiration, catheter drainage, sclerotherapy, and lymphangiography with lymphatic embolization. A review of these treatment options and a suggested algorithm for managing lymphoceles is presented.

Associations between model-predicted rivaroxaban exposure and patient characteristics and efficacy and safety outcomes in the prevention of venous thromboembolism

Anticoagulant plasma concentrations and patient characteristics might affect the benefit–risk balance of therapy. The study objective was to assess the impact of model-predicted rivaroxaban exposure and patient characteristics on outcomes in patients receiving rivaroxaban for venous thromboembolism (VTE) prophylaxis (VTE-P) after hip/knee replacement surgery. Post hoc exposure–response analyses were conducted using data from the phase 3 RECORD1–4 studies, in which 12,729 patients were randomized to rivaroxaban 10 mg once daily or enoxaparin for ≤ 39 days. Multivariate regression approaches were used to correlate model-predicted individual rivaroxaban exposures and patient characteristics with outcomes. In the absence of measured rivaroxaban exposure, exposure estimates were predicted based on individual increases in prothrombin time (PT) and by making use of the known correlation between rivaroxaban plasma concentration and dynamics of PT. No significant associations between rivaroxaban exposure and total VTE or major bleeding were identified. A significant association between exposure and a composite of major or non-major clinically relevant (NMCR) bleeding from day 4 after surgery was observed. The relationship was shallow, with an approximate predicted absolute increase in a composite of major or NMCR bleeding from 1.08 [95% confidence interval (CI) 0.76–1.54] to 2.18% (95% CI 1.51–3.17) at the 5th and 95th percentiles of trough plasma concentration, respectively. In conclusion, based on the underlying data and analysis, no reliable target window for exposure with improved benefit–risk could be identified within the investigated exposure range. Hence, monitoring rivaroxaban levels is unlikely to be beneficial in VTE-P.

Associations between model-predicted rivaroxaban exposure and patient characteristics and efficacy and safety outcomes in patients with non-valvular atrial fibrillation

Rivaroxaban exposure and patient characteristics may affect the rivaroxaban benefit–risk balance. This study aimed to quantify associations between model-predicted rivaroxaban exposure and patient characteristics and efficacy and safety outcomes in patients with non-valvular atrial fibrillation (NVAF), using data from the phase 3 ROCKET AF trial (NCT00403767). In ROCKET AF, 14,264 patients with NVAF were randomized to rivaroxaban (20 mg once daily [OD], or 15 mg OD if creatinine clearance was 30–49 mL/min) or dose-adjusted warfarin (median follow-up: 707 days); rivaroxaban plasma concentration was measured in a subset of 161 patients. In this post hoc exposure–response analysis, a multivariate Cox model was used to correlate individual predicted rivaroxaban exposures and patient characteristics with time-to-event efficacy and safety outcomes in 7061 and 7111 patients, respectively. There was no significant association between model-predicted rivaroxaban trough plasma concentration (C_trough) and efficacy outcomes. Creatinine clearance and history of stroke were significantly associated with efficacy outcomes. C_trough was significantly associated with the composite of major or non-major clinically relevant (NMCR) bleeding (hazard ratio [95th percentile vs. median]: 1.26 [95% confidence interval 1.13–1.40]) but not with major bleeding alone. The exposure–response relationship for major or NMCR bleeding was shallow with no clear threshold for an acceleration in risk. History of gastrointestinal bleeding had a greater influence on safety outcomes than C_trough. These results support fixed rivaroxaban 15 mg and 20 mg OD dosages in NVAF. Therapeutic drug monitoring is unlikely to offer clinical benefits in this indication beyond evaluation of patient characteristics.

Minimally invasive treatment of abdominal lymphocele: A review of contemporary options and how to approach them

Lymphoceles are lymphatic fluid collections resulting from lymphatic vessel disruption after surgery or trauma. They are most often described following retroperitoneal surgeries such as cystectomies, prostatectomies, renal transplants, and gynecologic surgeries. Most lymphoceles are asymptomatic and resolve spontaneously without treatment. If persistent, they can become infected or exert mass effect on adjacent structures causing pain, urinary, or lower limb edema particularly for lymphoceles in the pelvis Symptomatic lymphoceles should be treated to relieve symptoms and prevent functional compromise of vital adjacent structures. Although surgery has been traditionally accepted as the gold standard treatment, advances in imaging and interventional technology allow for less invasive, percutaneous treatment. Available minimally invasive treatment options include percutaneous aspiration, catheter drainage, sclerotherapy, and lymphangiography with lymphatic embolization. A review of these treatment options and a suggested algorithm for managing lymphoceles is presented.

Randomized phase 2 trial comparing JNJ-9375, a thrombin-directed antibody, with apixaban for prevention of venous thrombosis

BACKGROUND

JNJ-9375 is an antibody against exosite 1 on thrombin, inhibits substrate binding but not catalytic activity.

OBJECTIVE

To examine the possibility that JNJ-9375 attenuates thrombosis without affecting hemostasis, we compared the efficacy and safety of JNJ-9375 and apixaban.

METHODS

In this double-blind, double-dummy phase 2 trial, 308 patients undergoing knee arthroplasty were randomized to receive either a single postoperative intravenous infusion of JNJ-9375 in doses ranging from 0.3 to 1.8 mg/kg or apixaban (2.5 mg twice daily). The primary efficacy endpoint was the incidence of venous thromboembolism (assessed by mandatory unilateral venography or confirmed symptomatic events). The primary safety outcome was the composite of major, clinically relevant nonmajor, and minimal bleeding. Thrombin times were measured to assess JNJ-9375 activity.

RESULTS

A total of 239 of the 308 patients (77.6%) were included in the modified intention-to-treat analysis. Of these, 238 had evaluable venograms and one had symptomatic deep-vein thrombosis confirmed by ultrasound. Despite dose-dependent thrombin time prolongation, the primary efficacy outcome occurred in 59 of 190 patients (31.1%) in the combined JNJ-9375 groups as compared with 6 of 49 patients (12.2%) given apixaban (odds ratio 3.2; two-sided 80% confidence interval 1.8-5.8; P = .011). The excess events with JNJ-9375 compared with apixaban were consistent across all JNJ-9375 dosing cohorts and there was no evidence of improved efficacy with higher JNJ-9375 doses. There were no major bleeds with JNJ-9375 or apixaban, and rates of any bleeding were similar with the highest and lowest JNJ-9375 doses.

CONCLUSIONS

JNJ-9375 was safe but less effective than apixaban. This may reflect weak thrombin inhibition or inability of JNJ-9375 to attenuate the growth of thrombi that formed before drug administration.

Influence of model-predicted rivaroxaban exposure and patient characteristics on efficacy and safety outcomes in patients with acute coronary syndrome

Background:

This analysis aimed to evaluate the impact of rivaroxaban exposure and patient characteristics on efficacy and safety outcomes in patients with acute coronary syndrome (ACS) and to determine whether therapeutic drug monitoring might provide additional information regarding rivaroxaban dose, beyond what patient characteristics provide.

Methods:

A post hoc exposure–response analysis was conducted using data from the phase III ATLAS ACS 2 Thrombolysis in Myocardial Infarction (TIMI) 51 study, in which 15,526 randomized ACS patients received rivaroxaban (2.5 mg or 5 mg twice daily) or placebo for a mean of 13 months (maximum follow up: 31 months). A multivariate Cox model was used to correlate individual predicted rivaroxaban exposures and patient characteristics with time-to-event clinical outcomes.

Results:

For the incidence of myocardial infarction (MI), ischemic stroke, or nonhemorrhagic cardiovascular death, hazard ratios (HRs) for steady-state maximum plasma concentration (C_max) in the 5th and 95th percentiles versus the median were statistically significant but close to 1 for both rivaroxaban doses. For TIMI major bleeding events, a statistically significant association was observed with C_max [HR, 1.08; 95% CI, 1.06–1.11 (95th percentile versus median, 2.5 mg twice daily)], sex [HR, 0.56; 95% CI, 0.38–0.84 (female versus male)], and previous revascularization [HR, 0.62; 95% CI, 0.44–0.87 (no versus yes)].

Conclusions:

The shallow slopes of the exposure–response relationships and the lack of a clear therapeutic window render it unlikely that therapeutic drug monitoring in patients with ACS would provide additional information regarding rivaroxaban dose beyond that provided by patient characteristics.

Abstract 23: Patient Level Prediction Models Developed With Large Observational Databases Outperformed Existing Clinical Prediction Scores For Stratifying Bleeding Risk In Patients With Atrial Fibrillation

Background: Vitamin K antagonists (e.g., warfarin) and direct oral anticoagulants (DOACs; e.g., rivaroxaban, apixaban, dabigatran, edoxaban) are effective therapies for lowering the risk of thrombotic outcomes including stroke in patients with atrial fibrillation (AF). Like all anticoagulants, they are associated with an increased risk of bleeding. Several models (e.g., ATRIA, ORBIT, HAS-BLED, CHADS 2 and CHA 2 DS 2 -VASc) are available to predict the risk of major bleeding but their performance has not been widely evaluated in observational databases.

Objective: To develop patient-level bleeding risk prediction models and evaluate their performance compared to existing clinical models of bleeding.

Methods: Based on tools available through the Observational Health Data Science and Informatics Collaborative and Observed Medical Outcomes Partnership Common Data Model framework, we developed patient-level prediction (PLP) models to predict the risk of major bleeding events in patients with non-valvular AF who were new users of warfarin or DOACs. A LASSO regularized logistic regression technique including over 100,000 baseline covariates was performed across each of 4 US databases: IBM MarketScan ® (Commercial (CCAE), Medicaid (MDCD), and Medicare Supplemental (MDCR)) and Optum Clinformatics ® Extended Data Mart (Optum). We evaluated the performance of the PLP models compared with the existing models using the Area Under the Curve (AUC), with 75% training and 25% testing sets. The models were then externally validated by applying them to the other three databases.

Results: In each database, all the PLP models achieved higher internal validity (AUCs 0.69 - 0.83) compared with the existing clinical models. The highest AUC among the existing clinical models was 0.76 for CHA 2 DS 2 -VASc run on the DOACs new user population in the CCAE database; the comparative AUC for the PLP model was 0.79. The external validation of the PLP models was somewhat lower, the lowest being the new user DOACs models learned on the MDCD database and applied to the other three databases with AUCs between 0.56 and 0.58. This is possibly in part due to differences between patients in MDCD versus other databases (e.g., age, disability, socioeconomic status). The highest performing was the new user warfarin model learned on the Optum database validated on the CCAE database with an AUC of 0.75.

Conclusion: A patient level prediction model outperforms many existing clinical bleeding risk models currently in use.

Exosite 1 thrombin inhibition with JNJ-64179375 inhibits thrombus formation in a human translational model of thrombosis

AIMS

JNJ-64179375 (hereafter JNJ-9375) is a first-in-class, highly specific, large molecule, exosite 1 thrombin inhibitor. In preclinical studies, JNJ-9375 demonstrated robust antithrombotic protection with a wider therapeutic index when compared to apixaban. The purpose of the present study was to examine for the first time the antiplatelet, anticoagulant and antithrombotic effects of JNJ-9375 in a translational model of ex vivo human thrombosis.

METHODS AND RESULTS

Fifteen healthy volunteers participated in a double-blind randomized crossover study of JNJ-9375 (2.5, 25, and 250 μg/mL), bivalirudin (6 μg/mL; positive control), and matched placebo. Coagulation, platelet activation, and thrombus formation were determined using coagulation assays, flow cytometry, and an ex vivo perfusion chamber, respectively.JNJ-9375 caused concentration-dependent prolongation of all measures of blood coagulation (prothrombin time, activated partial thromboplastin time, and thrombin time; P < 0.001 for all) and agonist selective inhibition of thrombin (0.1 U/mL) stimulated platelet p-selectin expression (P < 0.001) and platelet-monocyte aggregates (P = 0.002). Compared to placebo, JNJ-9375 (250 μg/mL) reduced mean total thrombus area by 41.1% (95% confidence intervals 22.3 to 55.3%; P < 0.001) at low shear and 32.3% (4.9 to 51.8%; P = 0.025) at high shear. Under both shear conditions, there was a dose-dependent decrease in fibrin-rich thrombus (P < 0.001 for both) but not platelet-rich thrombus (P = ns for both).

CONCLUSION

Exosite 1 inhibition with JNJ-9375 caused prolongation of blood coagulation, selective inhibition of thrombin-mediated platelet activation, and reductions in ex vivo thrombosis driven by a decrease in fibrin-rich thrombus formation. JNJ-9375 represents a novel class of anticoagulant with potential therapeutic applications.

Rivaroxaban for Stroke Prevention after Embolic Stroke of Undetermined Source

BACKGROUND

Embolic strokes of undetermined source represent 20% of ischemic strokes and are associated with a high rate of recurrence. Anticoagulant treatment with rivaroxaban, an oral factor Xa inhibitor, may result in a lower risk of recurrent stroke than aspirin.

METHODS

We compared the efficacy and safety of rivaroxaban (at a daily dose of 15 mg) with aspirin (at a daily dose of 100 mg) for the prevention of recurrent stroke in patients with recent ischemic stroke that was presumed to be from cerebral embolism but without arterial stenosis, lacune, or an identified cardioembolic source. The primary efficacy outcome was the first recurrence of ischemic or hemorrhagic stroke or systemic embolism in a time-to-event analysis; the primary safety outcome was the rate of major bleeding.

RESULTS

A total of 7213 participants were enrolled at 459 sites; 3609 patients were randomly assigned to receive rivaroxaban and 3604 to receive aspirin. Patients had been followed for a median of 11 months when the trial was terminated early because of a lack of benefit with regard to stroke risk and because of bleeding associated with rivaroxaban. The primary efficacy outcome occurred in 172 patients in the rivaroxaban group (annualized rate, 5.1%) and in 160 in the aspirin group (annualized rate, 4.8%) (hazard ratio, 1.07; 95% confidence interval [CI], 0.87 to 1.33; P=0.52). Recurrent ischemic stroke occurred in 158 patients in the rivaroxaban group (annualized rate, 4.7%) and in 156 in the aspirin group (annualized rate, 4.7%). Major bleeding occurred in 62 patients in the rivaroxaban group (annualized rate, 1.8%) and in 23 in the aspirin group (annualized rate, 0.7%) (hazard ratio, 2.72; 95% CI, 1.68 to 4.39; P<0.001).

CONCLUSIONS

Rivaroxaban was not superior to aspirin with regard to the prevention of recurrent stroke after an initial embolic stroke of undetermined source and was associated with a higher risk of bleeding. (Funded by Bayer and Janssen Research and Development; NAVIGATE ESUS ClinicalTrials.gov number, NCT02313909 .).

Characterization of Patients with Embolic Strokes of Undetermined Source in the NAVIGATE ESUS Randomized Trial

BACKGROUND

The New Approach Rivaroxaban Inhibition of Factor Xa in a Global Trial vs. ASA to Prevent Embolism in Embolic Stroke of Undetermined Source (NAVIGATE-ESUS) trial is a randomized phase-III trial comparing rivaroxaban versus aspirin in patients with recent ESUS.

AIMS

We aimed to describe the baseline characteristics of this large ESUS cohort to explore relationships among key subgroups.

METHODS

We enrolled 7213 patients at 459 sites in 31 countries. Prespecified subgroups for primary safety and efficacy analyses included age, sex, race, global region, stroke or transient ischemic attack prior to qualifying event, time to randomization, hypertension, and diabetes mellitus.

RESULTS

Mean age was 66.9 ± 9.8 years; 24% were under 60 years. Older patients had more hypertension, coronary disease, and cancer. Strokes in older subjects were more frequently cortical and accompanied by radiographic evidence of prior infarction. Women comprised 38% of participants and were older than men. Patients from East Asia were oldest whereas those from Latin America were youngest. Patients in the Americas more frequently were on aspirin prior to the qualifying stroke. Acute cortical infarction was more common in the United States, Canada, and Western Europe, whereas prior radiographic infarctions were most common in East Asia. Approximately forty-five percent of subjects were enrolled within 30 days of the qualifying stroke, with earliest enrollments in Asia and Eastern Europe.

CONCLUSIONS

NAVIGATE-ESUS is the largest randomized trial comparing antithrombotic strategies for secondary stroke prevention in patients with ESUS. The study population encompasses a broad array of patients across multiple continents and these subgroups provide ample opportunities for future research.

A Cross-Study Analysis Evaluating the Effects of Food on the Pharmacokinetics of Rivaroxaban in Clinical Studies

US prescribing guidelines recommend that 15- and 20-mg doses of rivaroxaban be administered with food for the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE) and for reduction in the risk of recurrence of DVT and PE. In addition, the US prescribing guidelines recommend these doses be administered with an evening meal to reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation (AF). The purpose of this model-based cross-study comparison was to examine the impact of food, with regard to both meal timing and content, on the pharmacokinetics (PK) of rivaroxaban, using data collected during its clinical development. Results of this analysis showed that a PK model built from pooled data in the AF population (for whom rivaroxaban was administered with an evening meal) and in the DVT population (for whom rivaroxaban was administered with a morning meal) can describe both data sets well. Furthermore, the PK model built from data in the AF population alone can adequately predict the PK profile of the DVT population and vice versa. This cross-study analysis also confirmed the findings from previous clinical pharmacology studies, which showed that meal content does not have a clinically relevant impact on the PK of rivaroxaban at 20 mg. Therefore, although the administration of rivaroxaban with food is necessary for maintaining high bioavailability, neither meal timing nor meal content appears to affect the PK of rivaroxaban.

Life cycle assessment of sludge management with phosphorus utilisation and improved hygienisation in Sweden

To provide input to sewage sludge management strategies that address expected new regulations in terms of hygienisation and phosphorus recovery in Sweden, an environmental life cycle assessment (LCA) was made. The LCA identified environmental hot spots for methods that may permit sludge or phosphorus from sludge to be applied on agricultural land. In particular, thermophilic digestion, pasteurisation, thermal hydrolysis, urea treatment and mono-incineration with phosphorus recovery were compared. In addition, a sludge management system involving drying of sludge before use in forestry was investigated. The results showed that some major impacts are related to large uncertainties, such as those related to emissions from sludge storage. It also showed that large gains can be achieved when products from the systems replace other products, in particular when biogas is used to replace natural gas in vehicles, but also when sludge is used in agriculture and forestry. In general, there are small differences between the sludge management methods. Retaining the sludge matrix to allow for its utilisation in agriculture may conflict with keeping emissions to air and water from the sludge matrix low. It is recommended that any sludge management option minimises emissions from sludge to air and water and that resources are recovered and used, in line with the principles of a circular economy.

A Genetic Method To Evaluate the Prevalence of Unique DNA Profiles between Sequential Ground Beef Batches

The delineation of ground beef batches has implications for the management of product disposition policies in the event of Shiga toxin-producing Escherichia coli contamination. Analysis of individual contributor animal-specific DNA profiles can provide valuable empirical data for understanding the dynamics of ground meat production processes and can act as a surrogate for cross-contamination. A genetic method was developed for characterizing the source raw material flow and carryover between discrete batches of ground beef in a large-scale commercial beef grinding operation. The application developed involves the introduction of a genetically distinct source raw material batch into the grinding system and comprehensive sampling of that index batch and subsequent batches followed by single nucleotide polymorphism genotyping of random subsamples. Capture-mark-recapture statistical techniques were used to estimate (i) the number of carcass contributors and (ii) the associated level of carryover between batches. Carryover, expressed as a percentage of the total weight of the batch material (in pounds), was observed between the genetically distinct index batch and the next sequential batch at approximately 1%. The nondetection of additional carryover to subsequent batches, with a detection level of approximately 0.2%, supports a serial dilution model of same source raw material carryover, consistent with the recorded weight of beef trimmings used in each batch. For ground beef manufacturers, this method is a simple approach for validating the independence of finished batches of beef in their grind systems in support of product disposition policies.

Pharmacokinetics and Safety of Single Intravenous Doses of JNJ-54452840, an Anti-β1-Adrenergic Receptor Antibody Cyclopeptide, in Healthy Male Japanese and Caucasian Participants

AIM

To evaluate the pharmacokinetics and safety of single intravenous doses of JNJ-54452840 infused over 1 minute in healthy male Japanese and Caucasian participants. JNJ-54452840 is a novel peptide for the treatment of chronic heart failure, with a proposed mechanism of action of binding interference and decreased production of anti-β1-adrenergic receptor (anti-β1-AR) antibodies, which stimulate the cardiac β1-AR.

METHODS

In this randomized, single-centre, double-blind, placebo-controlled, four-way crossover study, 32 male Japanese and Caucasian participants (16 in each group) received single intravenous doses of JNJ-54452840 20, 80 and 240 mg, and placebo, each separated by a ≥7-day washout period. Pharmacokinetics and safety were assessed predose and at specified timepoints for 24 h. Anti-β1-AR antibodies were monitored.

RESULTS

The mean JNJ-54452840 maximum observed plasma concentration (C max) and area under the concentration-time curve from time zero to infinity with extrapolation of the terminal phase (AUCinf) values increased linearly with dose, with rapid elimination in both groups. Dose proportionality criteria were not met between the 20 and 240 mg doses for both study cohorts. The median time to reach C max (T max) ranged from 1 to 5 minutes. The mean total systemic clearance after intravenous administration (CL), volume of distribution at steady state (V ss), mean residence time (MRT) and terminal half-life (T ½) values were similar for both groups. The mean T ½ values ranged from 5.9 to 26.1 min in a dose-dependent manner. The overall prevalence of antibodies was 9.4 % at baseline; antibodies not present at baseline developed in five Caucasians (15.6 %) but not in Japanese participants. One participant in each group experienced a serious thromboembolic event (pulmonary embolism, ischaemic stroke).

CONCLUSION

JNJ-54452840 demonstrated similar pharmacokinetics in both groups. JNJ-54452840 was possibly immunogenic, and two participants reported thromboembolic serious adverse events. The relationship between these events and antibody formation is not known.

Rivaroxaban for secondary stroke prevention in patients with embolic strokes of undetermined source: Design of the NAVIGATE ESUS randomized trial

BACKGROUND

Embolic strokes of undetermined source comprise up to 20% of ischemic strokes. The stroke recurrence rate is substantial with aspirin, widely used for secondary prevention. The New Approach riVaroxaban Inhibition of Factor Xa in a Global trial versus ASA to prevenT Embolism in Embolic Stroke of Undetermined Source international trial will compare the efficacy and safety of rivaroxaban, an oral factor Xa inhibitor, versus aspirin for secondary prevention in patients with recent embolic strokes of undetermined source.

MAIN HYPOTHESIS

In patients with recent embolic strokes of undetermined source, rivaroxaban 15 mg once daily will reduce the risk of recurrent stroke (both ischemic and hemorrhagic) and systemic embolism (primary efficacy outcome) compared with aspirin 100 mg once daily.

DESIGN

Double-blind, randomized trial in patients with embolic strokes of undetermined source, defined as nonlacunar cryptogenic ischemic stroke, enrolled between seven days and six months from the qualifying stroke. The planned sample size of 7000 participants will be recruited from approximately 480 sites in 31 countries between 2014 and 2017 and followed for a mean of about two years until at least 450 primary efficacy outcome events have occurred. The primary safety outcome is major bleeding. Two substudies assess (1) the relative effect of treatments on MRI-determined covert brain infarcts and (2) the biological underpinnings of embolic strokes of undetermined source using genomic and biomarker approaches.

SUMMARY

The New Approach riVaroxaban Inhibition of Factor Xa in a Global trial versus ASA to prevenT Embolism in Embolic Stroke of Undetermined Source trial is evaluating the benefits and risks of rivaroxaban for secondary stroke prevention in embolic strokes of undetermined source patients. Main results are anticipated in 2018.

Post-invasion events after infection with Staphylococcus aureus are strongly dependent on both the host cell type and the infecting S. aureus strain

Host cell invasion is a major feature of Staphylococcus aureus and contributes to infection development. The intracellular metabolically active bacteria can induce host cell activation and death but they can also persist for long time periods. In this study a comparative analysis was performed of different well-characterized S. aureus strains in their interaction with a variety of host cell types. Staphylococcus aureus (strains 6850, USA300, LS1, SH1000, Cowan1) invasion was compared in different human cell types (epithelial and endothelial cells, keratinocytes, fibroblasts, osteoblasts). The number of intracellular bacteria was determined, cell inflammation was investigated, as well as cell death and phagosomal escape of bacteria. To explain strain-dependent differences in the secretome, a proteomic approach was used. Barrier cells took up high amounts of bacteria and were killed by aggressive strains. These strains expressed high levels of toxins, and possessed the ability to escape from phagolysosomes. Osteoblasts and keratinocytes ingested less bacteria, and were not killed, even though the primary osteoblasts were strongly activated by S. aureus. In all cell types S. aureus was able to persist. Strong differences in uptake, cytotoxicity, and inflammatory response were observed between primary cells and their corresponding cell lines, demonstrating that cell lines reflect only partially the functions and physiology of primary cells. This study provides a contribution for a better understanding of the pathomechanisms of S. aureus infections. The proteomic data provide important basic knowledge on strains commonly used in the analysis of S. aureus-host cell interaction.

Unveiling the molecular basis of antimicrobial resistance in Staphylococcus aureus from the Democratic Republic of the Congo using whole genome sequencing

Staphylococcus aureus from sub-Saharan Africa is frequently resistant to antimicrobial agents that are commonly used to treat invasive infections in resource-limited settings. The underlying mechanisms of resistance are largely unknown. We therefore performed whole genome sequencing (WGS) on S. aureus from the Democratic Republic of the Congo (DRC) to analyse the genetic determinants of antimicrobial resistance. One hundred S. aureus samples were collected from community-associated asymptomatic nasal carriers in the metropolitan area of Kinshasa, DRC, between 2013 and 2014. Phenotypic resistance against 15 antimicrobial agents was compared to the genotypic results that were extracted from WGS data using Mykrobe predictor and the SeqSphere(+) software that screened for 106 target genes associated with resistance. Isolates were phenotypically resistant against penicillin (97%, n=97), trimethoprim (72%, n=72) and tetracycline (54%, n=45). Thirty-three isolates (33%) were methicillin-resistant S. aureus (MRSA). Of these, nine isolates (27.3%) were oxacillin-susceptible MRSA (OS-MRSA) and belonged to ST8 (t1476). The Y195F mutation of FemA was associated with OS-MRSA (p 0.015). The majority of trimethoprim resistant isolates carried dfrG. Tetracycline resistance was associated with tet(K). The concordance between phenotypic susceptibility testing and both WGS analysis tools was similar and ranged between 96% and 100%. In conclusion, a high proportion of OS-MRSA in the DRC was linked to mutations of FemA. Genotypic and phenotypical antimicrobial susceptibility testing showed high concordance. This encourages the future use of WGS in routine antimicrobial susceptibility testing.

The MARINER trial of rivaroxaban after hospital discharge for medical patients at high risk of VTE. Design, rationale, and clinical implications

Hospital-associated venous thromboembolism (VTE) is a leading cause of premature death and disability worldwide. Evidence-based guidelines recommend that anticoagulant thromboprophylaxis be given to hospitalised medical patients at risk of VTE, but suggest against routine use of thromboprophylaxis beyond the hospital stay. The MARINER study is a randomised, double-blind, placebo-controlled trial to evaluate the efficacy and safety of thromboprophylaxis using rivaroxaban, begun at hospital discharge and continued for 45 days, for preventing symptomatic VTE in high-risk medical patients. Eligible patients are identified using the International Medical Prevention Registry on Venous Thromboembolism (IMPROVE VTE) risk score, combined with a laboratory test, D-dimer. The rivaroxaban regimen is 10 mg once daily for patients with CrCl ≥ 50 ml/min, or 7.5 mg once daily for patients with CrCl ≥ 30 ml/min and < 50 ml/min. The primary efficacy outcome is the composite of symptomatic VTE (lower extremity deep-vein thrombosis and non-fatal pulmonary embolism) and VTE-related death. The principal safety outcome is major bleeding. A blinded clinical events committee adjudicates all suspected outcome events. The sample size is event-driven with an estimated total of 8,000 patients to acquire 161 primary outcome events. Study design features that distinguish MARINER from previous and ongoing thromboprophylaxis trials in medically ill patients are: (i) use of a validated risk assessment model (IMPROVE VTE) and D-dimer determination for identifying eligible patients at high risk of VTE, (ii) randomisation at the time of hospital discharge, (iii) a 45-day treatment period and (iv) restriction of the primary efficacy outcome to symptomatic VTE events.

In the centre of an epidemic: Fifteen years of LA-MRSA CC398 at the University Hospital Münster

Ten years after initial publications on livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in 2005, we report on the course of the LA-MRSA CC398 epidemic among patients of the University Hospital Münster. This tertiary care facility is located in the Dutch-German border region (EUREGIO), which is characterized by a high density of livestock production and is hence a hotspot for the occurrence of LA-MRSA CC398. Taking advantage of the unique opportunity to track the emergence and spread of MRSA CC398 among humans from the very beginning of the epidemic until today, a total of 6555 non-duplicate MRSA isolates from all screenings and clinical specimens cultivated within the period from 2000 to 2014 were included in the analysis. Retrospectively, the first MRSA CC398 isolate (spa type t034) was obtained from a screening specimen of a patient in 2000, which represents one of the first human-associated LA-MRSA CC398 isolates reported in Europe. After sporadic detections between 2000 and 2004, this clonal lineage accounted for 9.6% of all local MRSA in 2005; a proportion which increased to 35% in 2013 and became stable since then. Considering the period from 2000 to 2014, the group of MRSA CC398 isolates comprised a total of 45 different spa types among which t011 (48.3%), t034 (39.3%) and t108 (3.5%) were predominant and so far unreported types were found. Overall, LA-MRSA CC398 emerged rapidly during the past decade, developed enormous sublineage diversity and contributed substantially to the total burden of MRSA colonization and infection at the hospital.

Direct blood culturing on solid medium outperforms an automated continuously monitored broth-based blood culture system in terms of time to identification and susceptibility testing

Pathogen identification and antimicrobial susceptibility testing (AST) should be available as soon as possible for patients with bloodstream infections. We investigated whether a lysis-centrifugation (LC) blood culture (BC) method, combined with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) identification and Vitek 2 AST, provides a time advantage in comparison with the currently used automated broth-based BC system. Seven bacterial reference strains were added each to 10 mL human blood in final concentrations of 100, 10 and 1 CFU/mL. Inoculated blood was added to the Isolator 10 tube and centrifuged at 3000 g for 30 min, then 1.5 mL sediment was distributed onto five 150-mm agar plates. Growth was observed hourly and microcolonies were subjected to MALDI-TOF MS and Vitek 2 as soon as possible. For comparison, seeded blood was introduced into an aerobic BC bottle and incubated in the BACTEC 9240 automated BC system. For all species/concentration combinations except one, successful identification and Vitek 2 inoculation were achieved even before growth detection by BACTEC. The fastest identification and inoculation for AST were achieved with Escherichia coli in concentrations of 100 CFU/mL and 10 CFU/mL (after 7 h each, while BACTEC flagged respective samples positive after 9.5 h and 10 h). Use of the LC-BC method allows skipping of incubation in automated BC systems and, used in combination with rapid diagnostics from microcolonies, provides a considerable advantage in time to result. This suggests that the usefulness of direct BC on solid medium should be re-evaluated in the era of rapid microbiology.

Staphylococcus aureus develops increased resistance to antibiotics by forming dynamic small colony variants during chronic osteomyelitis

OBJECTIVES

Staphylococcus aureus osteomyelitis often develops to chronicity despite antimicrobial treatments that have been found to be susceptible in in vitro tests. The complex infection strategies of S. aureus, including host cell invasion and intracellular persistence via the formation of dynamic small colony variant (SCV) phenotypes, could be responsible for therapy-refractory infection courses.

METHODS

To analyse the efficacy of antibiotics in the acute and chronic stage of bone infections, we established long-term in vitro and in vivo osteomyelitis models. Antibiotics that were tested include β-lactams, fluoroquinolones, vancomycin, linezolid, daptomycin, fosfomycin, gentamicin, rifampicin and clindamycin.

RESULTS

Cell culture infection experiments revealed that all tested antibiotics reduced bacterial numbers within infected osteoblasts when treatment was started immediately, whereas some antibiotics lost their activity against intracellular persisting bacteria. Only rifampicin almost cleared infected osteoblasts in the acute and chronic stages. Furthermore, we detected that low concentrations of gentamicin, moxifloxacin and clindamycin enhanced the formation of SCVs, and these could promote chronic infections. Next, we treated a murine osteomyelitis model in the acute and chronic stages. Only rifampicin significantly reduced the bacterial load of bones in the acute phase, whereas cefuroxime and gentamicin were less effective and gentamicin strongly induced SCV formation. During chronicity none of the antimicrobial compounds tested showed a beneficial effect on bone deformation or reduced the numbers of persisting bacteria.

CONCLUSIONS

In all infection models rifampicin was most effective at reducing bacterial loads. In the chronic stage, particularly in the in vivo model, many tested compounds lost activity against persisting bacteria and some antibiotics even induced SCV formation.

Systematic literature analysis and review of targeted preventive measures to limit healthcare-associated infections by meticillin-resistant Staphylococcus aureus

Meticillin-resistant Staphylococcus aureus (MRSA) is a major cause of healthcare-associated infections in Europe. Many examples have demonstrated that the spread of MRSA within healthcare settings can be reduced by targeted infection control measures. The aim of this systematic literature analysis and review was to summarise the evidence for the use of bacterial cultures for active surveillance the benefit of rapid screening tests, as well as the use of decolonisation therapies and different types of isolation measures. We included 83 studies published between 2000 and 2012. Although the studies reported good evidence supporting the role of active surveillance followed by decolonisation therapy, the effectiveness of single-room isolation was mostly shown in non-controlled studies, which should inspire further research regarding this issue. Overall, this review highlighted that when planning the implementation of preventive interventions, there is a need to consider the prevalence of MRSA, the incidence of infections, the competing effect of standard control measures (e.g. hand hygiene) and the likelihood of transmission in the respective settings of implementation.

Darstellung und Charakterisierung von Tetrabutylammonium-Tetraiodooxotechnetat(V), (TBA) [TcOI4] / Preparation and Characterization of Tetrabutylammonium Tetraiodooxotechnetate(V), (TBA)[TcOI4]

Pure (TBA)[TcOI4] is prepared from (TBA)[TcOCl4] by ligand exchange reaction with Nal in acetone. The vibrational spectra indicate C4v symmetry for the complex ion. On excitation with the 514.5 nm line of an Ar-laser a resonance Raman spectrum is obtained showing v(TcO) = 996 cm-1 and four of its overtones, symmetrically surrounded by groups of bands arising as well from the sums as from the differences of frequencies with the other fundamentals. In contrast to the ligand exchange reaction the reduction of Tc04- with conc. HI yields products always contaminated with polyiodides. The extremely strong Raman scatterer (TBA)l3 is detected by a characteristic doublet at 111 and 116 cm-1 and even small amounts of it cover the Raman spectrum of (TBA)[TcOI4].

195Pt- und 19F-NMR-Spektren der Fluoro-Chloro-Platinate(IV), [PtFnCl6-n]2-, n = 0-6 / 195Pt and 19F NMR Spectra of the Fluoro-Chloro-Platinates(IV), [PtFnCl6-n]2-, n = 0-6

The 10 complex ions of the system [PtFnCl6-n]2-, n = 0—6, including the three pairs of stereoisomers for n = 2, 3, 4 have been characterized by 195Pt and 19F NMR spectroscopy in CD2Cl2 solution. A wide range from 4731 ([PtCl6]2-) to 11816 ppm ([PtF6]2-) is covered by the clearly separated 195Pt resonances. The chemical shift δ(195Pt) depends nearly linearly on the sum of the electronegativities of the ligands. In accordance with increasing deshielding of the 195Pt nucleus by increasing coordination with F ligands an averaged major downfield shift of 1181 ppm per substitution of Cl by F is observed, while a minor averaged value of 354 ppm downfield is found for the trans/mer isomers in comparison to the related cis/fac isomers. Coupling with 19F results in characteristic 195Pt multiplets, with 1J(PtF) coupling constants for symmetric F—Pt—F axes of averaged 1890 Hz about 31% larger than 1J(PtF•) for asymmetric F•—Pt—Cl′ axes with averaged 1296 Hz. The data reflect the trans influence of the ligands. Highly resolved and expanded 195Pt spectra reveal clearly separated isotopomer signals with intensities according to the expected statistical ratios given by the natural abundance of 35Cl and 37Cl. For [Pt35Cln 37Cl6-n]2- five distinct signals related to n = 6-2 with 0,18 ppm highfield shift per 37Cl atom have been reliably assigned. Resolved isotopomer peaks have also been observed for mer-[PtF3 35Cl3]2-/mer-[PtF3 35Cl2 37Cl]2- with 0,21 ppm and for [PtF5 35Cl]2/[PtF5 37Cl]2- with 0,32 ppm highfield shift per 37Cl atom, respectively. The 19F resonances of symmetric axes appear at higher field, in the range from —357 to —382 ppm, than those of asymmetric axes, from —266 to —287 ppm. Under high resolution compounds with inequivalent F nuclei show multiplets originating from homonuclear 2J(FF•) couplings of about 40 Hz.

Preparation of Octabromoditechnetate(III,II), [Tc2Br8]3- and the Vibronic Structure of the δ → δ* Transition

The dinstinct vibronic structure of the δ → δ* transition of Cs3[Tc2Br8] with its mixed valence is well resolved at 6 K. The electronic origin at about 5970 cm-1 is split into four components, each giving rise to progressions entirely assignable in terms of nν1 and nν1 + ν2 up to n = 9, utilizing the totally symmetric stretching modes ν1(TcTc) and ν2(TcBr) exclusively.

Darstellung und Charakterisierung der Tetrabutylammoniumsalze von [Tc2Cl8]2-, [Tc2Cl8]3- und [Tc2Br8]2- Preparation and Characterization of the Tetrabutylammonium Salts of [Tc2Cl8]2-, [Tc2Cl8]3- und [Tc2Br8]2-

The reduction of [TcCl6]2- with Zn in conc. HCl after evaporation and extraction of ZnCl2 by diethylether yields a red-brown product from which after dissolving in dilute HCl by a solution of (TBA)Cl in CH2Cl2 (TBA)2[Tc2Cl8] and (TBA)3[Tc2Cl8] can be extracted. The separation is achieved by the much better solubility of the green (TBA)2[Tc2Cl8] in acetone compared with that of the grey-blue (TBA)3[Tc2Cl8]. On treatment of (TBA)2[Tc2Cl8] dissolved in acetone with bromine-free conc. HBr carmine red (TBA)2[Tc2Br8] is obtained for the first time. The vibrational spectra are similar and can be assigned according to the assumed D4h-symmetry. In the Raman spectra of both octachloroditechnetates the intensive Tc-Tc-vibration (A1g) is observed at 307 cm-1, for (TBA)2[Tc2Br8] it is found at 323 cm-1 . The electronic spectrum of (TBA)2[Tc2Cl8] agrees to a high extent with that of the corresponding Re compound