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Obesity and underweight are a growing health problem worldwide and a challenge for clinicians concerning antithrombotic therapy, due to the associated risks of thrombosis and/or bleeding. This clinical consensus statement updates a previous one published in 2018, by reviewing the most recent evidence on antithrombotic drugs based on body size categories according to the World Health Organization classification. The document focuses mostly on individuals at the extremes of body weight, i.e. underweight and moderate-to-morbid obesity, who require antithrombotic drugs, according to current guidelines, for the treatment or prevention of cardiovascular diseases or venous thromboembolism. Managing antithrombotic therapy or thromboprophylaxis in these individuals is challenging, due to profound changes in body composition, metabolism and organ function, and altered drug pharmacokinetics and pharmacodynamics, as well as weak or no evidence from clinical trials. The document also includes artificial intelligence simulations derived from in silico pharmacokinetic/pharmacodynamic models, which can mimic the pharmacokinetic changes and help identify optimal regimens of antithrombotic drugs for severely underweight or severely obese individuals. Further, bariatric surgery in morbidly obese subjects is frequently performed worldwide. Bariatric surgery causes specific and additional changes in metabolism and gastrointestinal anatomy, depending on the type of the procedure, which can also impact the pharmacokinetics of antithrombotic drugs and their management. Based on existing literature, the document provides consensus statements on optimizing antithrombotic drug management for underweight and all classes of obese patients, while highlighting the current gaps in knowledge in these complex clinical settings, which require personalized medicine and precision pharmacology., (© 2024 the European Society of Cardiology.)

Background: Tinzaparin could be easier to manage than unfractionated heparin in patients with severe renal impairment. However, clinical and pharmacologic data regarding its use in such patients are lacking., Objectives: The aims of this study were to determine, in patients with estimated glomerular filtration rate (eGFR) of <30 mL.min⁻ 1 , tinzaparin pharmacokinetics (PK) parameters using a population PK approach and bleeding and thrombotic complications., Methods: We performed a retrospective observational single-center study, including in-patients with eGFR of <30 mL.min⁻ 1 receiving prophylactic (4500 IU.d⁻ 1 ) or therapeutic (175 IU.kg⁻ 1 .d⁻ 1 ) tinzaparin. Measured anti-Xa levels were analyzed using a nonlinear mixed-effects modeling approach. Individual predicted tinzaparin exposure markers at steady state were calculated for each patient and dosing regimen. The PK was also evaluated through Monte Carlo simulations based on the final covariate model parameter estimates., Results: Over a 22-month period, 802 tinzaparin treatment periods in 623 patients were analyzed: two-thirds received a prophylactic dose, 66% had an eGFR of <20 mL.min⁻ 1 , and 25% were on renal replacement therapy. In patients for whom anti-Xa measurements were performed (n = 199; 746 values), PK parameters, profiles, and maximum plasma concentrations were comparable with those in patients without renal impairment or in healthy volunteers. In the whole population, major bleeding occurred in 2.4% and 3.5% of patients receiving prophylactic and therapeutic doses over a median 9- and 7-day treatment period, respectively. No patients had thrombotic complications., Conclusion: Tinzaparin PK parameters and profiles were not affected by renal impairment. This suggests that tinzaparin, at therapeutic or prophylactic dose, could be an alternative to unfractionated heparin in hospitalized patients with severe renal impairment., Competing Interests: Declaration of competing interests I.G.T. has received honoraria from Aguettant, Bayer, BMS-Pfizer, Leo-Pharma, Sanofi, Stago, and Viatris. G.M. has received honoraria from Bayer Healthcare, BMS-Pfizer, Leo-Pharma, and Sanofi. P.M. has received honoraria from Bayer Healthcare, BMS-Pfizer, Leo-Pharma, and Sanofi. P.G. has received honoraria from Sanofi. All other authors declare no conflicts of interest., (Copyright © 2024. Published by Elsevier Inc.)

Pulmonary embolism is a critical medical condition and can lead to cardiovascular arrest or death if left untreated. Pulmonary delivery of an anti-coagulant therapeutic could provide a locally limited and efficient therapy, moreover combined with a potentially fast onset of the therapeutic effect that is demanded in emergency situations. Rivaroxaban (riva) was formulated as an inhalable dry powder that can be administered directly to the lungs in order to reach high local drug doses. Particles obtained spray drying dichloromethane-methanol mixtures yielded an aerodynamic diameter of about or smaller than 5 µm and were found to reach an emitted fine particle fraction (FPF EF ) of at least 60 %. Pulmonary administration to rats using a dry powder insufflator revealed a nearly immediate therapeutic onset confirmed by the anticoagulant effects after 5 min in the plasma, followed by a plateau over the next 4 h. Such rivaroxaban particles were further formulated in binary blends using different lactose carriers (Inhalac® 70/251/400). These interactive blends resulted in high emitted fractions of at least 87 %, and furthermore, the highest fine particle fraction - total dose (FPF TD ) (60 %) of all tested formulations was achieved by using Inhalac® 400 as a carrier. The data strongly suggest a significant therapeutic potential of a rivaroxaban dry powder formulation, combining fast onset and a plateau of plasma concentrations turning it into a potential first aid therapeutic., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: [Alf Lamprecht reports equipment, drugs, or supplies was provided by Meggle. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper]., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

Existing conventional antithrombosis drugs have caused many side effects, opening up opportunities for the development of new thrombotic drugs. There is potential to use the hispidulin-rich fraction of sesewanua (HRFS) as a new antithrombotic. The oral route limitation of hispidulin, as a low water solubility and non-polar compound, can be addressed. This study explores the potential of HRFS in the form of dissolving microneedles (DMN). The formula was created using polymers such as polyvinyl alcohol (PVA), polyvinyl pyrrolidone K-30 (PVP), and non-ionic surfactant. Ex vivo permeation studies found that 184.95 µg/cm 2 of hispidulin was released 60 h after the best formulation. After 14 days of applying HRFS-DMN, the anticoagulant and antioxidant activity in male albino rats showed higher Activated Partial Thromboplastin Time (aPTT) and Prothrombin Time (PT) values and lower Inter Cellular Adhesion Molecule-1 (ICAM-1) values. No statistically significant differences were found between the effects of two and four HRFS-DMN and the injection of heparin at a dosage of 200 IU per kilogram. However, notable distinctions were observed when comparing HRFS-DMN to negative controls, oral and quercetin as positive controls at anti-ICAM activity. The findings confirmed the feasibility of HRFS-DMN for thrombosis and its effectiveness in delivering Hispidulin (HIS) into the bloodstream. This DMN is non-irritating, safe, and painless, showing promising outcomes in enhancing the efficacy of thrombosis treatment via the transdermal route., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Purpose: Abiraterone, apalutamide, darolutamide and enzalutamide are second-generation hormone therapies used for advanced prostate cancer; the majority of patients receiving these treatments are elderly, poly-medicated patients. Since their first market authorizations, their pharmacokinetic (PK) characteristics are increasingly well known. A potential risk of drug-drug interaction (DDI), especially with cardiovascular drugs, needs to be considered. In the case of antithrombotics, treatment imbalance can lead to severe consequences., Objectives: To describe PK profiles of hormone therapies and antithrombotics and to predict DDIs and potentially related clinical events., Methods: PK profiles (CYP450 and P-gp substrate, inducer or inhibitor) are described by cross-referencing data sources (summary of product characteristics, European public assessment reports, PubMed database, Micromedex ® , etc.); a description of the potential interactions with anti-cancer drugs for each DDI and related clinical events is provided. We discuss management recommendations, including those set out in international guidelines., Results: Antithrombotics are mainly metabolized by CYP 2C9, 2C19 or 3A4. For abiraterone (CYP 2C8, 2D6 inhibitor) and darolutamide (CYP 3A4 inducer), no interaction was identified with antithrombotics. For apalutamide (CYP 2C9, 2C19, 3A4 and P-gp inducer) and enzalutamide (CYP 2C9, 2C19, 3A4 inducer and P-gp inhibitor), several PK interactions were identified with antithrombotics, which could lead to various clinical events (haemorrhage or thromboembolism)., Conclusion: Numerous interactions are expected between enzalutamide or apalutamide and antithrombotics, for which management should be deployed on a case-by-case basis. PK and pharmaco-epidemiological studies could shed light on whether or not there are clinically significant events related to DDIs with antithrombotics., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Introduction: The drug most frequently used for thrombolysis in cases of acute ischemic stroke (AIS) is alteplase. However, there is moderate-to-high-quality evidence that tenecteplase has similar or higher efficacy and safety. With improved pharmacokinetic properties over alteplase, tenecteplase could be a significant advantage in treating AIS., Areas Covered: After conducting an extensive search on Scopus and PubMed, this manuscript reviews and compares the pharmacokinetic properties of alteplase and tenecteplase. Additionally, it provides information on pharmacodynamics, clinical efficacy, safety, tolerability, and drug-drug interactions., Expert Opinion: The pharmacokinetic profile of alteplase and tenecteplase is derived from studies in patients with acute myocardial infarction. Thanks to its pharmacokinetic properties, tenecteplase is the drug closest to being the ideal fibrinolytic for AIS. Its longer half-life enables a single-bolus administration, which is particularly useful in emergencies. Tenecteplase has proven to have a good efficacy and safety profile in randomized clinical trials. Although we are awaiting the results of the ongoing phase 3 randomized clinical trials, we believe that tenecteplase has the potential to revolutionize the treatment of AIS through thrombolysis.

The pharmacokinetics (PK) of tenecteplase in patients with acute ischemic stroke has not been extensively studied. This study aimed to describe PK characteristics of tenecteplase in patients with acute myocardial infarction (AMI) using a population PK approach and to assess applicability of the findings to patients with acute ischemic stroke by means of external validation. A population PK model was developed using nonlinear mixed-effects modeling based on the phase II TIMI 10B study in patients with AMI (785 PK observations from 103 patients). The statistical and clinical impact of selected covariates on PK parameters were evaluated by a stepwise covariate modeling procedure and simulations, respectively. The performance of the final model was evaluated for patients with acute ischemic stroke using summary statistics of tenecteplase concentrations of 75 patients from investigator-initiated study N1811s. Tenecteplase PK was well described by a 2-compartment linear model, incorporating allometric scaling of clearance and volume parameters and weight-normalized creatinine clearance on clearance. Simulations showed that the identified covariates (weight and creatinine clearance) were of limited influence on exposure at the intended dosing regimen for patients with acute ischemic stroke. The model overpredicted mean tenecteplase plasma concentrations from N1811s by 39%, but 72% of the distribution from N1811s was within the 90% prediction interval of the model predictions. The PK characteristics of tenecteplase in patients with AMI were well described by the final model. Simulations from the model indicated that no specific dose recommendations based on covariates are warranted for patients with AMI., (© 2022 The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals LLC on behalf of American College of Clinical Pharmacology.)

Desmoteplase is a bat (Desmodus rotundus) saliva-derived fibrinolytic enzyme resembling a urokinase and tissue plasminogen activator. It is highly dependent on fibrin and has some neuroprotective attributes. Intravenous administration of desmoteplase is safe and well tolerated in healthy subjects. Plasma fibrinolytic activity is linearly related to its blood concentration, its terminal elimination half-life ranges from 3.8 to 4.92 h (50 vs. 90 μg/kg dose). Administration of desmoteplase leads to transitory derangement of fibrinogen, D-dimer, alpha2-antiplasmin, and plasmin and antiplasmin complex which normalize within 4-12 h. It does not alter a prothrombin test, international normalized ratio, activated partial thromboplastin time, and prothrombin fragment 1.2. Desmoteplase was tested in myocardial infarction and pulmonary embolism and showed promising results versus alteplase. In ischemic stroke trials, desmoteplase was linked to increased rates of symptomatic intracranial hemorrhages and case fatality. However, data from "The desmoteplase in Acute Ischemic Stroke" Trials, DIAS-3 and DIAS-J, suggest that the drug is well tolerated and its safety profile is comparable to placebo. Desmoteplase is theoretically a superior thrombolytic because of high fibrin specificity, no activation of beta-amyloid, and lack of neurotoxicity. It was associated with better outcomes in patients with significant stenosis or occlusion of a proximal precerebral vessels. However, DIAS-4 was stopped as it might have not reached its primary endpoint. Due to its promising properties, desmoteplase may be added into treatment of ischemic stroke with extension of the time window and special emphasis on patients presenting outside the 4.5-h thrombolysis window, with wake-up strokes and strokes of unknown onset., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Factor XIa (FXIa) is an enzyme in the coagulation cascade thought to amplify thrombin generation but has a limited role in hemostasis. From preclinical models and human genetics, an inhibitor of FXIa has the potential to be an antithrombotic agent with superior efficacy and safety. Reversible and irreversible inhibitors of FXIa have demonstrated excellent antithrombotic efficacy without increased bleeding time in animal models (Weitz, J. I., Chan, N. C. Arterioscler. Thromb. Vasc. Biol. 2019, 39 (1), 7-12). Herein, we report the discovery of a novel series of macrocyclic FXIa inhibitors containing a pyrazole P2' moiety. Optimization of the series for (pharmacokinetic) PK properties, free fraction, and solubility resulted in the identification of milvexian ( BMS-986177/JNJ-70033093 , 17 , FXIa K i = 0.11 nM) as a clinical candidate for the prevention and treatment of thromboembolic disorders, suitable for oral administration.

The interaction of platelet GPIbα with von Willebrand factor (VWF) is essential to initiate platelet adhesion and thrombosis, particularly under high shear stress conditions. However, no drug targeting GPIbα has been developed for clinical practice. Here we characterized anfibatide, a GPIbα antagonist purified from snake (Deinagkistrodon acutus) venom, and evaluated its interaction with GPIbα by surface plasmon resonance and in silico modeling. We demonstrated that anfibatide interferds with both VWF and thrombin binding, inhibited ristocetin/botrocetin- and low-dose thrombin-induced human platelet aggregation, and decreased thrombus volume and stability in blood flowing over collagen. In a single-center, randomized, and open-label phase I clinical trial, anfibatide was administered intravenously to 94 healthy volunteers either as a single dose bolus, or a bolus followed by a constant rate infusion of anfibatide for 24 h. Anfibatide inhibited VWF-mediated platelet aggregation without significantly altering bleeding time or coagulation. The inhibitory effects disappeared within 8 h after drug withdrawal. No thrombocytopenia or anti-anfibatide antibodies were detected, and no serious adverse events or allergic reactions were observed during the studies. Therefore, anfibatide was well-tolerated among healthy subjects. Interestingly, anfibatide exhibited pharmacologic effects in vivo at concentrations thousand-fold lower than in vitro, a phenomenon which deserves further investigation.Trial registration: Clinicaltrials.gov NCT01588132.

Introduction: Alteplase is an approved treatment for acute ischemic stroke. Tenecteplase is a genetically modified form of alteplase, with lower cost and a more favourable pharmacokinetic profile allowing bolus injection. The aim of this study was to compare both drugs in adult patients with acute ischemic stroke undergoing thrombolysis., Material and Methods: PubMed and CENTRAL were searched for observational and experimental studies comparing both drugs in the population of interest. Additional studies were sought in clinical trial registries and by means of reference check. The efficacy outcomes of interest were functional status at 3 months, recanalization and early neurological improvement (ENI). The safety outcomes of interest were cerebral haemorrhage (ICH), symptomatic ICH and mortality. The effect measure of interest was the absolute risk difference (ARD). Effect measures for each outcome were pooled across studies using random effect models., Results: Eight studies were included, involving 2031 patients. Overall, there were no differences in terms of good or excellent functional outcome (ARR = 0.07 and 0.03 respectively, p > 0.05 for both comparisons) but tenecteplase patients showed higher rates of recanalization (ARD = 0.11, 95% CI [0.01;0.20]) and ENI (ARD = 0.10, 95% CI [0.02;0.17]). There were no differences between groups in terms of ICH (ARD = -0.02, 95% CI [-0.06;0.01]), symptomatic ICH (ARD = 0.00, 95% CI [-0.01;0.02]) or death (ARD = 0.00, 95% CI [-0.03;0.03])., Conclusion: Tenecteplase is an alternative to alteplase for stroke thrombolysis, with lower cost and a more favourable pharmacokinetic profile., Competing Interests: Declaration of Competing Interest None., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: To investigate the efficacy of tenecteplase (TNK), a genetically modified variant of alteplase with greater fibrin specificity and longer half-life than alteplase, prior to endovascular thrombectomy (EVT) in patients with basilar artery occlusion (BAO)., Methods: To determine whether TNK is associated with better reperfusion rates than alteplase prior to EVT in BAO, clinical and procedural data of consecutive patients with BAO from the Basilar Artery Treatment and Management (BATMAN) registry and the Tenecteplase vs Alteplase before Endovascular Therapy for Ischemic Stroke (EXTEND-IA TNK) trial were retrospectively analyzed. Reperfusion >50% or absence of retrievable thrombus at the time of the initial angiogram was evaluated., Results: We included 110 patients with BAO treated with IV thrombolysis prior to EVT (mean age 69 [SD 14] years; median NIH Stroke Scale score 16 [interquartile range (IQR) 7-32]). Nineteen patients were thrombolysed with TNK (0.25 mg/kg or 0.40 mg/kg) and 91 with alteplase (0.9 mg/kg). Reperfusion >50% occurred in 26% (n = 5/19) of patients thrombolysed with TNK vs 7% (n = 6/91) thrombolysed with alteplase (risk ratio 4.0, 95% confidence interval 1.3-12; p = 0.02), despite shorter thrombolysis to arterial puncture time in the TNK-treated patients (48 [IQR 40-71] minutes) vs alteplase-treated patients (110 [IQR 51-185] minutes; p = 0.004). No difference in symptomatic intracranial hemorrhage was observed (0/19 [0%] TNK, 1/91 [1%] alteplase; p = 0.9)., Conclusions: TNK may be associated with an increased rate of reperfusion in comparison with alteplase before EVT in BAO. Randomized controlled trials to compare TNK with alteplase in patients with BAO are warranted., Clinicaltrialsgov Identifiers: NCT02388061 and NCT03340493., Classification of Evidence: This study provides Class III evidence that TNK leads to higher reperfusion rates in comparison with alteplase prior to EVT in patients with BAO., (© 2021 American Academy of Neurology.)

Fucosylated chondroitin sulfate (FCS) polysaccharide isolated from sea cucumber has potent anticoagulant activity. Based on its resistance to the enzymes present in vertebrates, it may serve as an anticoagulant and shows antithrombotic effects when delivered through gastro-resistant (GR) tablets. However, due to the multiple plasma targets of FCS polysaccharide in the coagulation pathway, bleeding can occur after its oral administration. In the current study, we used FCS oligomers, in particular a mixture of oligosaccharides having 6 to 18 saccharide units, as the active ingredient in GR microcapsules for oral anticoagulation. In a Caco-2 model, the FCS oligomers showed higher absorption than native FCS polysaccharides. Oral administration of FCS oligomer-GR microcapsules provided a dose-dependent, prolonged anticoagulant effect with a selective inhibition of the intrinsic coagulation pathway when compared with subcutaneous administration of FCS oligomers or oral administration of unformulated FCS oligomers or native FCS-GR microspheres. Continued oral administration of FCS oligomer-GR microcapsules did not result in the accumulation of oligosaccharides in the plasma. Venous thrombosis animal models demonstrated that FCS oligomers delivered via GR microcapsules produced a potent antithrombotic effect dependent on their anticoagulant properties in the plasma, while oral administration of unformulated FCS oligomers at the same dose exhibited a weaker antithrombotic effect than the formulated version. Oral administration of FCS oligomer-GR microcapsules resulted in no bleeding, while oral administration of native FCS-GR microcapsules resulted in bleeding ( p  < 0.05). Our present results suggest that a FCS oligomer-GR microcapsule formulation represents an effective and safe oral anticoagulant for potential clinical applications., Competing Interests: None declared., (Thieme. All rights reserved.)

A selective and sensitive procedure for quantitation of a new antithrombotic drug (GRS) in rat plasma was developed and validated using an HPLC-UV. The method was validated according to recommendations of the FDA, EMA in terms of selectivity, linearity, accuracy, precision, recovery, matrix effect, stability, and carry-over. The preparation of the biological sample included liquid-liquid extraction with acetonitrile, separation of water-organic mixture with inorganic salts, organic phase clean-up with a sorbent (QuEChERS method), its evaporation to dryness and reconstitution of the residue with A:B eluents mixture (1:1). The chromatographic separations were performed on a micro-column 75 × 2 mm, 5 μm particle size sorbent ProntoSIL 120-5-C 18 AQ. The flowrate was of 0.15 ml/min, detector wavelength was set at 360 nm for GRS and at 230 nm for papaverine (IS). It was found that GRS recovery from rat plasma is 94%, the response linearity is in the range of 10 to 1000 ng ml -1 . The accuracy values for intra-day determination were of 93.2 to 101.8%, for inter-day determination were of 91.2 to 102.2%, coefficient of variation for intra- and inter-day precision did not exceed 4.1 to 9.3%. The application of the method was shown in pharmacokinetic studies of GRS in rats at a dose of 20 mg kg -1 ., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Objective: PAR (protease-activated receptor)-4 antagonism has antiplatelet effects under conditions of high shear stress. We aimed to establish whether PAR4 antagonism had additive antithrombotic activity in the presence of factor Xa inhibition in an ex vivo model of acute arterial injury. Approach and Results: Fifteen healthy volunteers (29±6 years, 7 women) completed a phase zero double-blind randomized controlled crossover trial. Ex vivo platelet activation, platelet aggregation, and thrombus formation were measured following blood perfusion of low shear and high shear stress chambers. Upstream of the chambers, extracorporeal blood was admixed with (1) vehicle, (2) low-dose apixaban (20 ng/mL), (3) high-dose apixaban (80 ng/mL), (4) BMS-986141 (400 ng/mL), (5) BMS-968141 and low-dose apixaban, or (6) BMS-968141 and high-dose apixaban in 6 sequential studies performed in random order. Compared with vehicle, BMS-986141 demonstrated selective inhibition of PAR4-AP (agonist peptide)-stimulated platelet aggregation, platelet-monocyte aggregates, and P-selectin expression ( P ≤0.01 for all). Total thrombus area was reduced under both low shear and high shear stress conditions for all drug infusions ( P <0.0001 for all versus vehicle). BMS-968141 reduced total (≤44.4%) and platelet-rich (≤39.3%) thrombus area, whereas apixaban reduced total (≤42.9%) and fibrin-rich (≤31.6%) thrombus area. Combination of BMS-986141 with apixaban caused a further modest reduction in total thrombus area (9.6%-12.4%), especially under conditions of high shear stress ( P ≤0.027)., Conclusions: In the presence of factor Xa inhibition, PAR4 antagonism with BMS-986141 further reduces thrombus formation, especially under conditions of high shear stress. This suggests the potential for additive efficacy of combination PAR4 antagonism and factor Xa inhibition in the prevention of atherothrombotic events.

Essential thrombocythemia (ET) patients are treated with aspirin (acetylsalicylic acid [ASA]) to prevent thrombosis. Previous studies showed that serum thromboxane (Tx) B 2 was high 24 hours after enteric-coated (EC)-ASA in ET patients, due to increased number of noninhibited reticulated platelets (RPs), consequent to high platelet turnover, and that ASA should be given twice a day to ET patients. We studied ET patients ( n  = 17) and healthy subjects ( n  = 10) on 100 mg EC-ASA once daily; experiments were repeated after 14-day treatment with 100 mg plain-ASA once daily. Serum TxB 2 , plasma ASA, and salicylic acid (SA) were measured before the morning dose and up to 8 hours thereafter. Blood activity of ASA-deacethylating esterases, in vitro inhibition of collagen-induced TxB 2 production by ASA (10-1,000 µM), and number of RP were measured. TxB 2 inhibition by ASA in vitro and esterases activities were normal in all subjects. EC-ASA elicited highly variable responses; 6 ET patients were poor responders, as their serum TxB 2 was high after EC-ASA; their plasma levels of ASA and SA were low/undetectable. In contrast to EC-ASA, plain ASA decreased serum TxB 2 and increased plasma ASA and SA in all subjects. Serum TxB 2 was high in ET patients at 24 hours and significantly correlated with RP count (but not RP percentage) and platelet count. Plain ASA should be used in ET patients to inhibit platelets efficiently. The identification of ET patients who might benefit from twice a day ASA could simply be based on their platelet count: since their platelet turnover is not increased, ET patients with normalized platelet count should not need twice a day ASA treatment., Competing Interests: None declared., (Thieme. All rights reserved.)

Competing Interests: Dr. Bikdeli reports that he is a consulting expert, on behalf of the plaintiff, for litigation related to a specific type of inferior vena cava filters. Dr. Madhavan reports being supported by an institutional grant by the National Institutes of Health/National Heart, Lung, and Blood Institute to Columbia University Irving Medical Center (T32 HL007854).

Intravascular thrombosis is a main cause of multiple cardiovascular diseases. A high thrombolytic activity of the microbial fibrinolytic enzyme Subtilisin QK-2, which is highly homologous to Nattokinase, shows great exploitable potential in thrombolytic therapy. However, the lack of a sensitive detection method limits the further analysis of Subtilisin QK-2 in vivo. We prepared a polyclonal antibody and four monoclonal antibodies (IgG1, titers of 1:500,000) to establish a sensitive sandwich ELISA for Subtilisin QK-2 detection. The limit of detection (LOD) of this ELISA was 1.160 ng/mL. The linear range of the standard curve was 1.96-250 ng/mL (R 2  = 0.9912). The cut-off value was 0.236. Subsequently, a pharmacokinetic dose (IV bolus) was administered and analyzed with the established ELISA. The concentration-time profiles were best fitted to a two-compartment model. T1/2α values for doses of 2 mg/kg, 4 mg/kg, and 8 mg/kg were 29.90 ± 10.02 min, 27.17 ± 1.96 min, and 21.83 ± 9.95 min, and T1/2β values were 144.43 ± 49.73 min, 173.46 ± 52.58 min, and 159.49 ± 48.75 min, respectively. Subtilisin QK-2 was eliminated through a mechanism with first-order kinetics. In conclusion, this study provides useful data for further research and clinical applications of Subtilisin QK-2 in the treatment of cardiovascular diseases., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Oral factor XIa (FXIa) inhibitors may provide a promising new antithrombotic therapy with an improved benefit to bleeding risk profile over existing antithrombotic agents. Herein, we report application of a previously disclosed cyclic carbamate P1 linker which provided improved oral bioavailability in the imidazole-based 13-membered macrocycle to the 12-membered macrocycle. This resulted in identification of compound 4 with desired FXIa inhibitory potency and good oral bioavailability but high in vivo clearance. Further structure-activity relationship (SAR) studies of heterocyclic core modifications to replace the imidazole core as well as various linkers to the P1 group led to the discovery of compound 6f , a potent FXIa inhibitor with selectivity against most of the relevant serine proteases. Compound 6f also demonstrated excellent pharmacokinetics (PK) profile (high oral bioavailability and low clearance) in multiple preclinical species. Compound 6f achieved robust antithrombotic efficacy in a rabbit efficacy model at doses which preserved hemostasis.

Low-molecular-weight heparins (LMWHs) are the mainstay of the prophylaxis and treatment of venous thromboembolism (VTE). Due to their renal elimination, the risk of accumulation with the related bleeding risk may represent a limitation for the use of LMWHs in patients with chronic kidney disease (CKD) as the risk of major bleeding is increased in patients with creatinine clearance (CrCl) < 30 mL/min, especially in patients with cancer. LMWH structure and molecular weight (MW) are heterogeneous among available agents. The elimination of tinzaparin, which has the highest mean MW among LMWHs, is less dependent on renal function as it is also metabolized through the reticuloendothelial system. A subcutaneous therapeutic dose of tinzaparin (175 IU/kg) once daily has been shown to cause no accumulation of anti-factor Xa activity in patients with CrCl ≥ 20 mL/min. Clinical experience from randomized controlled studies has shown no significant impact of CKD on bleeding risk in cancer patients receiving treatment doses of tinzaparin. This suggests that in these patients the use of treatment doses of tinzaparin does not require anticoagulation monitoring or dose adjustment.

Background and Purpose- The RE-SPECT ESUS trial (Randomized, Double-Blind, Evaluation in Secondary Stroke Prevention Comparing the Efficacy and Safety of the Oral Thrombin Inhibitor Dabigatran Etexilate Versus Acetylsalicylic Acid in Patients With Embolic Stroke of Undetermined Source) tested the hypothesis that dabigatran would be superior to aspirin for the prevention of recurrent stroke in patients with embolic stroke of undetermined source. This exploratory subgroup analysis investigates the impact of age, renal function (both predefined), and dabigatran dose (post hoc) on the rates of recurrent stroke and major bleeding. Methods- RE-SPECT ESUS was a multicenter, randomized, double-blind trial of dabigatran 150 or 110 mg (for patients aged ≥75 years and/or with creatinine clearance 30 to <50 mL/minute) twice daily compared with aspirin 100 mg once daily. The primary outcome was recurrent stroke. Results- The trial, which enrolled 5390 patients from December 2014 to January 2018, did not demonstrate superiority of dabigatran versus aspirin for prevention of recurrent stroke in patients with embolic stroke of undetermined source. However, among the population qualifying for the lower dabigatran dose, the rate of recurrent stroke was reduced with dabigatran versus aspirin (7.4% versus 13.0%; hazard ratio, 0.57 [95% CI, 0.39-0.82]; interaction P =0.01). This was driven mainly by the subgroup aged ≥75 years (7.8% versus 12.4%; hazard ratio, 0.63 [95% CI, 0.43-0.94]; interaction P =0.10). Stroke rates tended to be lower with dabigatran versus aspirin with declining renal function. Risks for major bleeding were similar between treatments, irrespective of renal function, but with a trend for lower bleeding rates with dabigatran versus aspirin in older patients. Conclusions- In subgroup analyses of RE-SPECT ESUS, dabigatran reduced the rate of recurrent stroke compared with aspirin in patients qualifying for the lower dose of dabigatran. These results are hypothesis-generating. Aspirin remains the standard antithrombotic treatment for patients with embolic stroke of undetermined source. Registration- URL: https://www.clinicaltrials.gov; Unique identifier: NCT02239120.

DS-1040, a novel low-molecular-weight inhibitor of activated thrombin-activatable fibrinolysis inhibitor, is under development for the treatment of thromboembolic diseases including venous thromboembolism and acute ischemic stroke. Here we describe the results of 3 studies that evaluated the safety and tolerability of DS-1040 along with the effect on DS-1040 pharmacokinetic (PK) parameters, when dosed alone or when coadministered with aspirin (NCT02071004), clopidogrel (NCT02560688), or enoxaparin in healthy subjects. Concomitant administration of single-dose DS-1040 with multiple-dose aspirin, multiple-dose clopidogrel, or single-dose enoxaparin, consistent with clinically relevant dose regimens, was safe and well tolerated with no serious treatment-emergent adverse events (TEAEs), TEAEs leading to discontinuation, bleeding-related TEAEs, and no significant changes in coagulation parameters. DS-1040 did not prolong bleeding time when administered concomitantly with aspirin or clopidogrel. In the aspirin study, DS-1040 PK was evaluated following the concomitant administration with multiple-dose aspirin, where the plasma DS-1040 exposure (peak plasma concentration [C max ] and area under the concentration-time curve [AUC inf ]) was to be similar to the data previously published in the first-in-human study of DS-1040 in healthy subjects. The PK parameters of DS-1040 coadministered with clopidogrel were similar to those of DS-1040 alone, with small increases in geometric means for C max (7%) and AUC last (9%). When coadministered with enoxaparin, the PK parameters of DS-1040 were not affected (1.1% and 1.5% decreases in geometric means for C max and AUC last , respectively). Therefore, concomitant administration of DS-1040 and clopidogrel or enoxaparin did not demonstrate PK drug-drug interactions., (© 2020, The American College of Clinical Pharmacology.)

Astaxanthin (ASTX) has been reported as a potential therapeutic agent for hepatic fibrosis treatment. However, its therapeutic effect is limited due to low bioavailability and poor aqueous solubility. In this study, biopolymer-based nanoparticles were fabricated using stearic acid-chitosan conjugate (SA-CS) and sodium caseinate (NaCas) via ionic gelation. Its nanostructure was cross-linked using oxidized dextran (Odex) via Schiff base reaction. Concentration of cross-linker, cross-linking temperature and time were systematically optimized by response surface methodology (RSM) to achieve superior particulate properties and colloidal stability. The optimized nanoparticles exhibited a diameter of 120 nm with homogeneous size distribution. A good ASTX encapsulation capacity with up to 6% loading ratio and high encapsulation efficiency was obtained. The final ASTX concentration in nanoparticles was 140 μM. The aqueous dispersibility of encapsulated ASTX was greatly improved, which was confirmed by significantly increased ABTS radical scavenging capacity. Compared to the anti-fibrogenic effect of free ASTX in LX-2 cells, the encapsulated ASTX demonstrated dramatically enhanced cellular bioactivity, as evidenced by significantly lower TGFβ1-induced fibrogenic gene (ACTA2 and COL1A1) expression level, as well as α-SMA and COL1A1 protein levels. This study suggests that the as-prepared biopolymer nanoparticles hold promising features as an oral delivery vehicle for lipophilic bioactives., Competing Interests: Declaration of competing interest There are no conflicts of interest to declare., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Pleural empyema is an inflammatory condition characterized by accumulation of pus inside the pleural cavity, which is usually followed by bacterial pneumonia. During the disease process, the pro-inflammatory and pro-fibrotic cytokines in the purulent pleural effusion cause proliferation of fibroblasts and deposition of extracellular matrix, which lead to fibrin deposition and fibrothorax. Urokinase instillation therapy through a chest drainage tube is frequently used for fibrinolysis in patients with empyema. However, urokinase treatment requires multiple instillation (2-3 times per day, for 4-8 days) and easily flows out from the chest drainage tube due to its high water solubility. In this in vitro study, we developed a thermo-responsive hydrogel based on poloxamer 407 (P407) combined with hyaluronic acid (HA) for optimal loading and release of urokinase. Our results show that the addition of HA to poloxamer gels provides a significantly more compact microstructure, with smaller pore sizes (**p < 0.001). The differential scanning calorimetry (DSC) profile revealed no influence on the micellization intensity of poloxamer gel by HA. The 25% poloxamer-based gel was significantly superior to the 23% poloxamer-based gel, with slower gel erosion when comparing the 16th hour residual gel weight of both gels (*p < 0.05; **p < 0.001). The 25% poloxamer-HA gel also exhibited a superior urokinase release profile and longer release time. A Fourier-transform infrared spectroscopy (FT-IR) study of the P407/HA hydrogel showed no chemical interactions between P407 and HA in the hydrogel system. The thermoresponsive P407/HA hydrogel may have a promising potential in the loading and delivery of hydrophilic drugs. On top of that, in vitro toxicity test of this combination demonstrates a lower toxicity., Competing Interests: The authors have declared that no competing interests exist.

Background: Thrombotic events continue to be a major cause of morbidity and mortality worldwide. Tissue plasminogen activator (tPA) is used for the treatment of acute ischemic stroke and other thrombotic disorders. Use of tPA is limited by its narrow therapeutic time window, hemorrhagic complications, and insufficient delivery to the location of the thrombus. Magnetic nanoparticles (MNPs) have been proposed for targeting tPA delivery. It would be advantageous to develop an improved in vitro model of clot formation, to screen thrombolytic therapies that could be enhanced by addition of MNPs, and to test magnetic drug targeting at human-sized distances., Methods: We utilized commercially available blood and endothelial cells to construct 1/8th inch (and larger) biomimetic vascular channels in acrylic trays. MNP clusters were moved at a distance by a rotating permanent magnet and moved along the channels by surface walking. The effect of different transport media on MNP velocity was studied using video photography. MNPs with and without tPA were analyzed to determine their velocities in the channels, and their fibrinolytic effect in wells and the trays., Results: MNP clusters could be moved through fluids including blood, at human-sized distances, down straight or branched channels, using the rotating permanent magnet. The greatest MNP velocity was closest to the magnet: 0.76 ± 0.03 cm/sec. In serum, the average MNP velocity was 0.10 ± 0.02 cm/sec. MNPs were found to enhance tPA delivery, and cause fibrinolysis in both static and dynamic studies. Fibrinolysis was observed to occur in 85% of the dynamic MNP + tPA experiments., Conclusion: MNPs hold great promise for use in augmenting delivery of tPA for the treatment of stroke and other thrombotic conditions. This model system facilitates side by side comparisons of MNP-facilitated drug delivery, at a human scale., Competing Interests: Mr Sebastian P Pernal and Mr Alexander J Willis report gift support from Pulse Therapeutics, Inc. to the University of Illinois at Chicago during the conduct of the study. Mr Michael E Sabo reports grants from the National Institutes of Health, during the conduct of the study; he was an employee of Pulse Therapeutics Inc., during the submitted work. Ms Laura M Moore was an employee of Pulse Therapeutics, Inc. Mr Sean C Morris reports personal fees from Pulse Therapeutics, Inc., he also is an employee of Pulse Therapeutics Inc.. In addition, he has a patent 8715150 issued, a patent 9339664 issued, a patent 10029008 issued, a patent 8308628 issued, a patent 8313422 issued, a patent 8529428 issued, a patent 8926491 issued, a patent 9345498 issued, a patent 10159734 issued, a patent 9883878 issued, a patent 2010313105 issued, a patent 2777841 issued, a patent 2934401 issued, a patent ZL 201080060370.4 issued, a patent EP 2496302 issued, a patent 219515 issued, a patent 60 2010 058 639.1 issued, a patent 246714 issued, a patent 5865252 issued, a patent 6169677 issued, a patent 10-1616465 issued, a patent 324087 issued, a patent 2012/02947 issued, a patent EP 2849657 issued, a patent 60 2013 042 824.7 issued, a patent 6335163 issued, a patent 2019/0038748 pending, a patent 2019/0255174 pending, a patent 2018/0221041 pending, a patent WO/2011/053984 issued, a patent WO/2013/173235 issued, and a patent 15/886, 130 issued. Dr Francis M Creighton reports grants from NIH/NINDS, and grants from NIH/NIMHD, during the conduct of the study. In addition, he has a patent US10159734 issued, a patent US10029008 issued, a patent US9883878 issued, a patent US9345498 issued, a patent US8926491 issued, a patent US8715150 issued, a patent US8529428 issued, a patent US8313422 issued, and a patent US8308628 issued. Dr Herbert H Engelhard reports gifts and non-financial support, from Pulse Therapeutics, Inc. made to the University of Illinois at Chicago, during the conduct of the study. In addition, he has a patent “Tissue Culture Tray and System for the In Vitro Testing and Characterization of Magnetically-Induced Rotation and Translational Motion of Magnetic Particles” July 2017 US20180024109A1 pending. The authors report no other conflicts of interest in this work., (© 2020 Pernal et al.)

Factor XIa (FXIa) inhibitors are promising novel anticoagulants, which show excellent efficacy in preclinical thrombosis models with minimal effects on hemostasis. The discovery of potent and selective FXIa inhibitors which are also orally bioavailable has been a challenge. Here, we describe optimization of the imidazole-based macrocyclic series and our initial progress toward meeting this challenge. A two-pronged strategy, which focused on replacement of the imidazole scaffold and the design of new P1 groups, led to the discovery of potent, orally bioavailable pyridine-based macrocyclic FXIa inhibitors. Moreover, pyridine-based macrocycle 19 , possessing the phenylimidazole carboxamide P1, exhibited excellent selectivity against relevant blood coagulation enzymes and displayed antithrombotic efficacy in a rabbit thrombosis model.

Fibrinolytic agents including plasmin and plasminogen activators improve outcomes in acute ischemic stroke and thrombosis by recanalizing occluded vessels. In the decades since their introduction into clinical practice, several limitations of have been identified in terms of both efficacy and bleeding risk associated with these agents. Engineered nanoparticles and microparticles address some of these limitations by improving circulation time, reducing inhibition and degradation in circulation, accelerating recanalization, improving targeting to thrombotic occlusions, and reducing off-target effects; however, many particle-based approaches have only been used in preclinical studies to date. This review covers four advances in coupling fibrinolytic agents with engineered particles: (a) modifications of plasminogen activators with macromolecules, (b) encapsulation of plasminogen activators and plasmin in polymer and liposomal particles, (c) triggered release of encapsulated fibrinolytic agents and mechanical disruption of clots with ultrasound, and (d) enhancing targeting with magnetic particles and magnetic fields. Technical challenges for the translation of these approaches to the clinic are discussed., (© 2019 International Society on Thrombosis and Haemostasis.)

A marine fibrinolytic compound was studied for use in thrombolytic therapy. Firstly, the absorption and transportation characteristics of 2,5-B H PA (2,5-B H PA:2,5-Bis-[8-(4,8-dimethyl-nona-3,7-dienyl)-5,7-dihydroxy-8-methyl-3-keto-1,2,7,8-tertahydro-6 H -pyran[a]isoindol-2-yl]-pentanoic acid, a novel pyran-isoindolone derivative with bioactivity isolated from a rare marine microorganism in our laboratory) in the human Caco-2 cells monolayer model were investigated. We collected 2,5-B H PA in the cells to calculate the total recovery, and its concentration was analyzed by LC/MS/MS (Liquid Chromatography/ Mass Spectrum/ Mass Spectrum). The results showed that 2,5-B H PA has low permeability and low total recoveries in the Caco-2 cells membrane. Pharmacokinetics and tissue distribution of 2,5-B H PA were investigated in beagle dogs using HPLC (High Performance Liquid Chromatography) after intravenous administration of three different doses (7.5, 5.0, 2.5 mg·kg -1 ). Pharmacokinetic data indicated that 2,5-B H PA fitted well to a two-compartment model. Elimination half-lives (T 1/2 ) were 49 ± 2, 48 ± 2, and 49 ± 2 min, respectively; the peak concentrations (C max ) were 56.48 ± 6.23, 48.63 ± 5.53, and 13.64 ± 2.76 μg·mL -1 , respectively; clearance rates (CL) were 0.0062 ± 0.0004, 0.0071 ± 0.0008, and 0.0092 ±0.0006 L·min -1 ·kg -1 , respectively; mean retention times (MRT) were 28.17 ± 1.16, 26.23 ± 0.35, and 28.66 ± 0.84 min, respectively. The low penetrability of 2,5-B H PA indicated that the intravenous route of administration is more appropriate than the oral route. Meanwhile, 2,5-B H PA showed a good pharmacokinetic profile in beagle dogs. The tissue distribution showed that 2,5-B H PA could quickly distribute into the heart, intestines, liver, stomach, spleen, lungs, testicles, urine, intestine, kidneys, brain, and feces. The concentration of 2,5-B H PA was higher in the liver and bile. Interestingly, 2,5-B H PA was detected in the brain. Taken together, the above results suggested that our work might be beneficial in the development of agents for thrombolytic treatment., Competing Interests: The authors declare no conflict of interest.

In an effort to identify novel antithrombotics, we have investigated protease-activated receptor 4 (PAR4) antagonism by developing and evaluating a tool compound, UDM-001651 , in a monkey thrombosis model. Beginning with a high-throughput screening hit, we identified an imidazothiadiazole-based PAR4 antagonist chemotype. Detailed structure-activity relationship studies enabled optimization to a potent, selective, and orally bioavailable PAR4 antagonist, UDM-001651 . UDM-001651 was evaluated in a monkey thrombosis model and shown to have robust antithrombotic efficacy and no prolongation of kidney bleeding time. This combination of excellent efficacy and safety margin strongly validates PAR4 antagonism as a promising antithrombotic mechanism.

Background: The Fontan procedure is the final step of the 3-stage palliative procedure commonly performed in children with single ventricle physiology. Thrombosis remains an important complication in children after this procedure. To date, guideline recommendations for the type and duration of thromboprophylaxis after Fontan surgery are mainly based on extrapolation of knowledge gained from adults at risk for thrombosis in other clinical settings. Warfarin is being used off-label, and because of its multiple interactions with other drugs and food, a new alternative is highly desirable. Rivaroxaban, a direct Factor Xa inhibitor with a predictable pharmacokinetic profile, is a candidate to address this medical need., Study Design: The UNIVERSE study is a prospective, open-label, active-controlled, multicenter study in children 2 to 8 years of age who have single ventricle physiology and had the Fontan procedure within the 4 months preceding enrollment. This study consists of 2 parts. In Part A, rivaroxaban pharmacokinetics, pharmacodynamics, safety, and tolerability are assessed to validate the pediatric dosing selected. In Part B, safety and efficacy of rivaroxaban versus acetylsalicylic acid are evaluated for thromboprophylaxis in children post-Fontan procedure. Children in each part will receive study drug for 12 months. Part A has been completed with 12 children enrolled. Enrollment into Part B is currently ongoing., Conclusions: The UNIVERSE study aims to provide dosing, pharmacokinetics/pharmacodynamics, safety, and efficacy information on the use of rivaroxaban, an oral anticoagulant, versus acetylsalicylic acid, an antiplatelet agent, in children with single ventricle physiology after the Fontan procedure., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Hirudin, an extract from Hirudo spp., is an anticoagulant used to treat a variety of renal diseases, including diabetic nephropathy (DN). Currently, hirudin has to be used at high dosages to treat DN because it poorly targets the kidneys, although at high dosages it can have severe side effects. Developing a targeted drug delivery system for hirudin, then, could boost its positive therapeutic effects while lowering the risk of side effects. Liposomes have been demonstrated to have significant renal targeting potential, but here we show that a hirudin-loaded liposome is an effective delivery method for patients with DN., Method: In this study, we prepared a hirudin/liposome complex and tested its efficacy by injecting it into a rat model. We then compared the renal accumulation of hirudin between complex-injected rat models and rat models that received injections of hirudin alone. We also investigated the mechanisms behind the complex's effects., Result: The hirudin/liposome complex increased the accumulation of hirudin in kidney tissues and relieved the renal injury in DN rat models. Moreover, the hirudin/liposome complex down-regulated the expression of TGF-β1 and VEGF in the kidneys., Conclusion: We demonstrated that a hirudin/liposome complex can have a significant positive effect on DN. The mechanism may be that the complex inhibits the expression of VEGF and TGF-β1.

Background: Targeted neutrophil inhibitory-hirulog (TNHH) is a novel hybrid glycoprotein that may be a potential drug candidate for acute ischaemic stroke., Objective: The aim of this study was to evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of TNHH in healthy volunteers and thereby determine the dose range for future clinical studies., Methods: This randomized, placebo-controlled study was a single ascending dose design with dose levels of 0.05-1.8 mg/kg (n = 4-6 active, 2 placebos per cohort) in 68 participants. In the TNHH 0.2-1.8 mg/kg and control cohorts, pharmacokinetic and pharmacodynamic blood samples were collected over 168 h after intravenous (IV) administration. TNHH occupancy in peripheral blood neutrophils and blood coagulation were evaluated as the markers of target engagement., Results: Two subjects withdrew from the trial before administration of the study treatment, 66 subjects are included in the data analysis. TNHH was well tolerated in all dose regimens. In total, five mild, self-limiting adverse events (AEs) were observed in 4 of the 66 study subjects. Dose-proportional increases in maximum plasma concentration (C max ) and area under the curve (AUC 0-t ) of TNHH were observed. Traces of TNHH were excreted in urine. The elimination half-life (t ½ ) ranged from 0.6 to 1.3 h in the eight groups with ascending dose levels. TNHH combined with CD11b/CD18 quickly achieved > 90% receptor occupancy in groups with doses above 0.2 mg/kg. The C max and AUC of binding TNHH with CD11b/CD18 increased with the dose. A significant prolongation with dose was observed on thrombin time (TT), and weak influences were observed on prothrombin time (PT) and activated partial thromboplastin time (APTT)., Conclusion: TNHH was well-tolerated following IV infusion. The pharmacokinetic and pharmacodynamic characteristics of TNHH indicate that it merits clinical trials. It is recommended that the single dose of TNHH should be 1.0 mg/kg in future studies, and the expected effect may be achieved after 5-7 days of continuous administration., Trial Registration: The study is registered at http://www.chictr.org.cn as ChiCTR-TQR-14004752.

Objective: Blast injury is associated with multi-organ failure (MOF), causing significant morbidity and mortality in trauma patients. However, the pathogenesis of blast-induced MOF still remains obscure. In this study, we evaluate the pathophysiological changes related to blast-induced MOF in a clinically relevant rat model of blast injury., Methods: A moderate blast overpressure was applied to induce injury in anesthetized rats. Pathological changes were evaluated by H&E staining. Complement activation, plasminogen, and myeloperoxidase levels were analyzed by complement hemolytic assay (CH50) and/or ELISA in blood samples., Results: Analysis of lung, brain, and liver tissue at 24 hour after blast overpressure revealed severe injuries. The level of complement components C3 and C1q decreased in parallel with the reduction of CH50 level in injured animals at 1, 3, and 6 hours after blast. Consumption of plasminogen was also detected as early as 1 hour post-injury. Myeloperoxidase levels were elevated within 1 hour of blast injury., Conclusion: Our data reveal that blast injury triggers the complement and fibrinolytic systems, which likely contribute to blast-induced MOF. Conceivably, therapies that target these systems early may improve clinical outcomes in blast patients., (© Association of Military Surgeons of the United States 2019. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Thrombus diseases, induced by blood stasis or vascular embolization normally, frequently occur with high disability and mortalities worldwide. At present, drug thrombolysis, a primary clinical therapy for blood clot lysis, could increase the lethal risk for hemorrhage when thrombolysis agents are overused in the whole body. Therefore, a novel and advanced therapy for blood clot lysis, based on remote physical signals, is helpful for assisting clinical therapy. Here, we used the localized light-Au-hyperthermia (LAH) treatment, induced by gold nanorods (Au NRs) irradiated with near-infrared light (808 nm), for precise, rapid, and drug-free blood clot lysis. The LAH technology was first introduced in the murine hematoma model and the murine myocardial infarction model for blood clot lysis. Compared with traditional therapy, LAH was assured to shorten the time of detumescence in the murine hematoma model owing to their precise and localized hyperthermia. Meanwhile, we also discovered that LAH was a benefit to vascular recanalization in the murine myocardial infarction model. In addition, the Au NRs used in LAH present ideal biocompatibility in the murine model, which endows it to be suitable for blood clot lysis in vivo.

Purpose: Desmoteplase (DSPA) was evaluated and compared with tissue plasminogen activator (t-PA) for its intraocular fibrinolytic effect and short-term toxicity in an in vivo study using rabbit eyes., Methods: Fibrin clots were induced in the anterior chamber of 44 rabbit eyes, and drug efficacy was measured by clot size reduction over 24 h. Topical DSPA eye drops (1.4 and 2 mg/mL) were compared with vehicle solution in a multiple-drop regimen in 8 animals per group. Intracameral injections of 0.6 μg DSPA (n = 14) and 25 μg t-PA (n = 14) were evaluated for their fibrinolytic efficacy. Animals were euthanized 24 h after drug application., Results: No significant differences were seen between topically treated DSPA and vehicle-treated animals. Intracameral t-PA had a higher fibrinolytic efficacy than DSPA at early time points, but no significant difference was seen between both groups at 24-h postapplication. Animals with t-PA treatment demonstrated significantly more side effects compared with DSPA-treated animals. DSPA showed no-to-mild side effects after topical and intracameral treatment. Histologically, no toxic effects were observed in any globe., Conclusions: DSPA is a promising drug with fewer side effects and similar fibrinolytic efficacy compared with t-PA 24 h after intracameral application in rabbit eyes at the tested concentration. Drug efficacy might be improved by increasing intracameral DSPA doses.

Pyragrel is a novel thromboxane A2-synthetase inhibitor for the treatment of cerebral infarction, and it is currently being investigated in phase I clinical trials. This paper reports the first reliable LC-MS/MS method for the simultaneous determination of Pyragrel and its two main metabolites, M1 and M2, in human plasma. All analytes were extracted from human serum using liquid-phase extraction and separated on a Zorbax EcLipse XDB C18 column using isocratic elution with a mobile phase composed of methanol, water and formic acid (65:35:0.1, v/v/v). Determination of the analytes was achieved by tandem-mass spectrometry with positive electrospray ionization. The multiple reaction monitoring transitions under positive electrospray ionization were performed at m/z 329.0 → m/z 135.9 for Pyragrel, m/z 303.1 → m/z 135.0 for M1, m/z 331.2 → m/z 135.0 for M2, and 482.2 → m/z 258.0 for IS, respectively. The following parameters were validated: specificity, recovery, matrix effects, carry-over, linearity, sample stability under a variety of storage and handling conditions, and stock solution stability. The validated method has been successfully applied to an initial pharmacokinetic study in healthy volunteers following intravenous administrations of 60 mg of Pyragrel, and this method will facilitate further studies involving more comprehensive identification of the metabolic profile of Pyragrel and the appropriate dosage regimen., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: DLBS1033 is a bioactive protein fraction extracted from Lumbricus rubellus, with fibrinogenolytic, fibrinolytic and anti-aggregation activities reported in an in vitro study. Plasma half-life is an important parameter to calculate its dose. This study was conducted to evaluate the biological half-life of DLBS1033 by measuring serial plasmin-antiplasmin (PAP) complex. PAP complex is a stable and inactive compound as a result of fibrinolysis process., Methods: this was an open-label clinical trial in healthy adult subjects. Subjects were divided into two groups to receive single dose drugs (received 3 x 490 mg) or repeated administration until steady state conditions (3 x 490 mg/day for 3 days). Blood samples for PAP complex measurement were collected at time 0 (before drug administration for single dose group), then at 0.5, 1, 1.5, 2, 3, 6, 8, 10, 12, and 24 hours after drug administration. Safety parameters used in this study were creatinine, prothrombin time (PT), activated partial thromboplastin time (aPTT), SGOT, and SGPT., Results: the biological half-life of DLBS1033 was calculated based on the mean of PAP complex concentration on each time sampling. In single dose group, the highest mean of PAP complex concentration was reached before drug administration. Our result showed that the activity of DLBS1033 could not be determined after single dose administration. In steady state condition, the PAP complex concentration increase in 2 hours after last drug administration. The biological half-life of DLBS1033 was 8.6 hours. There were no significant safety findings on all laboratory parameters and no serious adverse events., Conclusion: it is concluded that the fibrinolytic effects of DLBS1033 can be measured in steady state condition. The biological half-life of DLBS1033 in steady state condition was 8.6 hours. There were no serious adverse events on two groups of subjects.

In patients with solid tumours or haematological malignancies, venous thromboembolism (VTE) is a leading cause of death and significantly contributes to morbidity and healthcare resource utilization. Current practice guidelines recommend long-term anticoagulation with low-molecular-weight heparin (LMWH) as the treatment of choice for cancer-associated VTE, based on clinical trial data showing an overall improved safety and efficacy profile of LMWH compared to vitamin K antagonists. However, several open questions remain, e. g. with regard to the intensity and duration of LMWH therapy; moreover, recent real-world evidence indicates that adherence to parenteral anticoagulation with LMWH over the course of treatment is poor in clinical practice. In this regard, the direct oral factor Xa or thrombin inhibitors (DOACs) have emerged as potential alternatives in the management of patients with cancer-associated VTE, albeit findings from randomized controlled studies with a direct head-to-head comparison of DOACs with LMWH, the current standard of care, are still lacking. Based on the case of a lymphoma patient experiencing symptomatic pulmonary embolism during immunochemotherapy, this article aims at both highlighting the current state-of-the-art approach to cancer-associated VTE and pointing out some of the unresolved, controversial issues clinicians have to face when taking care of haematology and oncology patients with already established or with high risk of developing VTE. These issues include the management of patients with incidental pulmonary embolism or thrombocytopenia, the use of DOACs, and the initiation of pharmacological thromboprophylaxis in non-surgical cancer patients.

Anagrelide is an established therapy for essential thrombocythemia. Common adverse effects have been linked to peak plasma concentrations of anagrelide and its 3OH metabolite. Our study was performed to investigate the pharmacokinetics (PK) of a novel anagrelide extended-release (AER) formulation and its active metabolites. Thirty healthy volunteers were randomized to receive either 2 mg AER (under fasting and fed conditions) or 2 mg commercially available reference product (CARP) in an open-label, 3-way crossover trial with washout periods of 6 days. Plasma concentrations of anagrelide and its active metabolites were assessed by tandem mass spectrometry. The PK differed significantly between all treatment periods. Bioavailability of AER was 55% of the CARP under fasting conditions and 60% under fed conditions. C max , AUCt, and AUC∞ were significantly higher and T max and T 1/2 were significantly shorter after the CARP compared with AER. Food had a significant impact on the PK of AER, increasing the C max and AUC t while reducing the T 1/2 , plateau, and mean residence time. Both formulations were well tolerated, with a trend toward more frequently occurring adverse events after the CARP. The PK of AER and the CARP differed significantly in all parameters. Food enhanced the bioavailability of AER., (© 2017, The Authors. Clinical Pharmacology in Drug Development Published by Wiley Periodicals, Inc. on behalf of The American College of Clinical Pharmacology.)

Objective: BMS-986120 is a novel first-in-class oral PAR4 (protease-activated receptor 4) antagonist with potent and selective antiplatelet effects. We sought to determine for the first time, the effect of BMS-986120 on human ex vivo thrombus formation., Approach and Results: Forty healthy volunteers completed a phase 1 parallel-group PROBE trial (Prospective Randomized Open-Label Blinded End Point). Ex vivo platelet activation, platelet aggregation, and thrombus formation were measured at 0, 2, and 24 hours after (1) oral BMS-986120 (60 mg) or (2) oral aspirin (600 mg) followed at 18 hours with oral aspirin (600 mg) and oral clopidogrel (600 mg). BMS-986120 demonstrated highly selective and reversible inhibition of PAR4 agonist peptide (100 μM)-stimulated P-selectin expression, platelet-monocyte aggregates, and platelet aggregation ( P <0.001 for all). Compared with pretreatment, total thrombus area (μm 2 /mm) at high shear was reduced by 29.2% (95% confidence interval, 18.3%-38.7%; P <0.001) at 2 hours and by 21.4% (9.3%-32.0%; P =0.002) at 24 hours. Reductions in thrombus formation were driven by a decrease in platelet-rich thrombus deposition: 34.8% (19.3%-47.3%; P <0.001) at 2 hours and 23.3% (5.1%-38.0%; P =0.016) at 24 hours. In contrast to aspirin alone, or in combination with clopidogrel, BMS-986120 had no effect on thrombus formation at low shear ( P =nonsignificant). BMS-986120 administration was not associated with an increase in coagulation times or serious adverse events., Conclusions: BMS-986120 is a highly selective and reversible oral PAR4 antagonist that substantially reduces platelet-rich thrombus formation under conditions of high shear stress. Our results suggest PAR4 antagonism has major potential as a therapeutic antiplatelet strategy., Clinical Trial Registration: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02439190., (© 2017 The Authors.)

With over 1.5 billion people, East Asians are the most populous race in the world. Health status in this population is an important global issue. In the contemporary trials of antithrombotic treatment, East Asian patients have a lower risk for atherothrombotic diseases (especially, Coronary Artery Disease [CAD]) and a higher risk for bleeding (especially, gastrointestinal bleeding and hemorrhagic stroke). Despite these observations, antithrombotic treatment strategies in East Asian patients are mainly based on the American or European guidelines that are derived from randomized, controlled trials including mostly Caucasians. Despite a low response to clopidogrel, East Asian patients with CAD show a similar or even a lower rate of ischemic event occurrence and higher bleeding risk compared with Caucasian patients. The latter is referred to as the "East Asian Paradox", suggesting a dissimilar therapeutic window for antiplatelet therapy than Caucasians. In addition, different net clinical benefits have been observed between the races with potent P2Y12 inhibitors that may be related to racial differences in pharmacokinetic and pharmacodynamic profiles. Furthermore, there is emerging concern regarding differences between East Asian vs. Western patients in pharmacodynamic and clinical efficacies of anticoagulant agents. We now summarize experimental and clinical evidence of the efficacy and safety of antithrombotic agents in the East Asian population. We suggest the concept of "race-tailored antithrombotic treatment" in CAD patients and/or in patients undergoing percutaneous coronary intervention., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Purpose: To determine whether intravitreal unconjugated tissue plasminogen activator (tPA) (alteplase) can penetrate the intact neural retina and reach the subretinal space in an experimental model., Methods: This study was performed in 24 Sprague-Dawley rats aged 12 weeks. Under general anesthesia, the right eye was injected with either 0.75 μg of 3 μL tPA (14 rats; study group) or saline (10 rats, control group) into the vitreous. Animals were euthanized at 3, 24, and 48 h. The eyes were enucleated, and cryosections were prepared for immunofluorescence staining. Goat anti-tPA antibody was used to detect tPA., Results: In the study group, staining for tPA was detected in the deep retinal layers in all eyes. The staining was deeper and more intense at 3 and 24 h than at 48 h. There was no tPA staining in the retina of eyes injected with saline., Conclusions: This experimental study shows that unconjugated tPA administered into the vitreous is capable of penetrating the deep retinal layers and the subretinal space. These findings suggest that further clinical research is warranted on the benefits of intravitreal tPA in the treatment of submacular hemorrhage., (© 2017 S. Karger AG, Basel.)

The present study aimed to prepare injectable Lumbrokinase (LK) with long circulation time in addition to enhanced anti-thrombotic efficacy. Following preparation, the pharmacokinetic and anti‑thrombotic effect of the drug in a rat carotid artery thrombosis model was evaluated. The drug was prepared by conjugation of LK with mPEG‑SC20000 as previously reported. The pharmacokinetics of the mPEG‑SC20000‑LK were then examined and the anti‑thrombotic activity in an artery‑vein bypass thrombosis rat model was evaluated. Finally, the parameters of fibrinolysis including thromboxane B2, prostaglandin F1α, tissue plasminogen activator and plasminogen activator inhibitor‑1 were compared between native LK and mPEG‑SC20000‑LK in a FeCl3‑induced carotid artery thrombosis rat model. mPEG‑SC20000‑LK was successfully prepared by PEGylation of LK with mPEG20000‑SC in optimal conditions. Pharmacokinetic analysis demonstrated that the biological half‑life of the mPEG20000‑SC‑LK increased by 2.2‑fold compared with native LK. In vivo anti‑thrombotic analysis indicated that mPEG20000‑SC‑LK exhibited a greater anti‑thrombotic effect in artery‑vein bypass thrombosis and FeCl3-induced carotid artery thrombosis models compared with native LK. In conclusion, injectable PEGylated LK with prolonged half-life and enhanced anti‑thrombotic effect is a potential anti‑thrombotic agent for long‑acting treatment of the thrombus diseases.

Background: GPVI (Glycoprotein VI) is the essential platelet collagen receptor in atherothrombosis. Dimeric GPVI-Fc (Revacept) binds to GPVI binding sites on plaque collagen. As expected, it did not increase bleeding in clinical studies. GPVI-Fc is a potent inhibitor of atherosclerotic plaque-induced platelet aggregation at high shear flow, but its inhibition at low shear flow is limited. We sought to increase the platelet inhibitory potential by fusing GPVI-Fc to the ectonucleotidase CD39 (fusion protein GPVI-CD39), which inhibits local ADP accumulation at vascular plaques, and thus to create a lesion-directed dual antiplatelet therapy that is expected to lack systemic bleeding risks., Methods and Results: GPVI-CD39 effectively stimulated local ADP degradation and, compared with GPVI-Fc alone, led to significantly increased inhibition of ADP-, collagen-, and human plaque-induced platelet aggregation in Multiplate aggregometry and plaque-induced platelet thrombus formation under arterial flow conditions. GPVI-CD39 did not increase bleeding time in an in vitro assay simulating primary hemostasis. In a mouse model of ferric chloride-induced arterial thrombosis, GPVI-CD39 effectively delayed vascular thrombosis but did not increase tail bleeding time in vivo., Conclusions: GPVI-CD39 is a novel approach to increase local antithrombotic activity at sites of atherosclerotic plaque rupture or injury. It enhances GPVI-Fc-mediated platelet inhibition and presents a potentially effective and safe molecule for the treatment of acute atherothrombotic events, with a favorable risk-benefit ratio., (© 2017 The Authors and AdvanceCor GmbH. Published on behalf of the American Heart Association, Inc., by Wiley.)

Bleeding is one of the most feared complications of flexible bronchoscopy. Although infrequent, it can be catastrophic and result in fatal outcomes. Compared to other endoscopic procedures, the risk of morbidity and mortality from the bleeding is increased, as even a small amount of blood can fill the tracheobronchial tree and lead to respiratory failure. Patients using antithrombotic agents (ATAs) have higher bleeding risk. A thorough understanding of the different ATAs is critical to manage patients during the peri-procedural period. A decision to stop an ATA before bronchoscopy should take into account a variety of factors, including indication for its use and the type of procedure. This article serves as a detailed review on the different ATAs, their pharmacokinetics and the pre- and post-bronchoscopy management of patients receiving these medications., Competing Interests: Conflict of interest: None declared., (Copyright ©ERS 2017.)

The constant increase in cardiovascular disease rate coupled with significant drawbacks of existing therapies emphasise the necessity to improve therapeutic strategies. Natural flavonoids exert innumerable pharmacological effects in humans. Here, we demonstrate the effects of chrysin, a natural flavonoid found largely in honey and passionflower on the modulation of platelet function, haemostasis and thrombosis. Chrysin displayed significant inhibitory effects on isolated platelets, however, its activity was substantially reduced under physiological conditions. In order to increase the efficacy of chrysin, a sulfur derivative (thio-chrysin), and ruthenium-complexes (Ru-chrysin and Ru-thio-chrysin) were synthesised and their effects on the modulation of platelet function were evaluated. Indeed, Ru-thio-chrysin displayed a 4-fold greater inhibition of platelet function and thrombus formation in vitro than chrysin under physiologically relevant conditions such as in platelet-rich plasma and whole blood. Notably, Ru-thio-chrysin exhibited similar efficacy to chrysin in the modulation of haemostasis in mice. Increased bioavailability and cell permeability of Ru-thio-chrysin compared to chrysin were found to be the basis for its enhanced activity. Together, these results demonstrate that Ru-thio-coupled natural compounds such as chrysin may serve as promising templates for the development of novel anti-thrombotic agents.

Novel anticoagulants (NAGs) have emerged as the preferred alternatives to vitamin K antagonists. In patients being considered for regional anesthesia, these drugs present a layer of complexity in the preprocedure evaluation. There are no established tests to monitor anticoagulant activity and our experience is short with these drugs. These authors believe it is important to review the relevant hematology, orthopedics, and anesthesiology literature to provide a valuable reference for the clinician who is met with these challenges. In addition to discussing NAGs, we also review the existing American Society of Regional Anesthesia guidelines for heparin, low-molecular-weight heparin, and antiplatelet agents., (Copyright © 2017 Elsevier Inc. All rights reserved.)