Factor Xa (FXa)

Human plasma's PT, TT, and APTT are prolonged by edoxaban in a concentration-dependent manner (1, 1, and 5 minutes, respectively)[1]. With an IC50 of 2.90 µM, edoxaban prevents platelet aggregation caused by thrombin[1].

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Inhibitory effect of Edoxaban/DU‐176b on FXa Inhibition of human FXa by DU‐176b was concentration‐dependent and competitive, as shown by the Lineweaver–Burk plot (Fig. 2). The Ki value was 0.561 nm (Table 1), a marked improvement in potency compared with DX‐9065a (Ki = 41 nm) [6]. DU‐176b also inhibited cynomolgus monkey and rabbit FXa with similar potency, whereas the Ki for rat FXa was higher than that for human FXa (Table 1), similar to the profile of DX‐9065a. For FXa bound to FVa, Ca2+ and phospholipids within the prothrombinase complex using S‐2222 as a substrate, inhibition by DU‐176b was competitive (Fig. 3A). The Ki value was 0.903 nm, comparable to its inhibition of free FXa. DU‐176b also suppressed the generation of thrombin from prothrombin by prothrombinase in a non‐competitive/mixed‐type of inhibition (Fig. 3B), with a 5.3‐fold higher Ki (2.98 nm) than that obtained with free FXa.

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Specificity of Edoxaban/DU‐176b DU‐176b was a weak inhibitor of thrombin and FIXa, with Ki values of 6.00 and 41.7 μm, respectively; more than 10 000‐fold higher than the Ki for FXa. There was no effect on the activities of FVIIa/sTF, FXIa, tPA, aPC, trypsin, plasmin and chymotrypsin, demonstrating the high specificity of DU‐176b for FXa.

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Anticoagulant activity in vitro PT, APTT and TT of human plasma were prolonged by Edoxaban/DU‐176b in a concentration‐dependent manner, doubling PT and APTT at 0.256 and 0.508 μm, respectively (Table 2). The CT2 for TT, however, was much higher (4.95 μm), reflecting its anti‐thrombin activity as shown in the enzyme inhibition assay. The potency of DU‐176b for PT prolongation was similar in human, cynomolgus monkey and rabbit plasma, whereas a higher concentration was needed in rat plasma.

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Effects on human platelet aggregation in vitro Edoxaban/DU‐176b did not impair human platelet aggregation induced by ADP, collagen or U46619 (a thromboxane A2 receptor agonist) at concentrations of up to 100 μm in PRP. Thrombin‐induced platelet aggregation was inhibited by a high concentration of DU‐176b (IC50: 2.90 μm), reflecting its weak anti‐thrombin activity.

Edoxaban prolongs PT and significantly and dose-dependently reduces thrombus formation at doses of 0.5, 2.5, and 12.5 mg/kg; po; once[1].

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PD and PK studies in rats and monkeys [1]
There was significant FXa inhibition activity in plasma (86% and 94% inhibition) in rats 0.5 h after oral administration of Edoxaban/DU‐176b (2.5 and 5 mg kg−1) (Fig. 4A), which was sustained for up to 4 h. In cynomolgus monkeys, DU‐176b also elicited a rapid onset of anti‐FXa activity, reaching a peak at 4 h (93%) and persisting 24 h (11%) after dosing (Fig. 4B). The area under the curve (AUC) of plasma concentration and maximum concentration (Cmax) after 1 mg kg−1 DU‐176b dosing were 852 ± 284 ng·h mL−1 and 175 ± 74 ng mL−1 (n = 6, mean ± standard deviation). Compared with DU‐176b, DX‐9065a had a lower anti‐FXa potency in both species (Fig. 4). AUC and Cmax in cynomolgus monkeys after the 1 mg kg−1 DX‐9065a dosing were 191 ± 104 ng·h mL−1 and 36.8 ± 20.5 ng mL−1 (n = 6).

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Antithrombotic effects of orally administered Edoxaban/DU‐176b [1]
Venous stasis thrombosis model in rats and rabbits Infusion of hypotonic saline and stasis of the inferior vena cava in rats led to the formation of thrombi weighing 4.38 ± 0.53 mg. Oral administration of DU‐176b (0.5, 2.5 and 12.5 mg kg−1) significantly and dose‐dependently reduced the thrombus formation (Fig. 5A) and prolonged PT (Fig. 5B). The plasma samples derived from DU‐176b‐treated rats inhibited exogenous FXa activity (Fig. 5C). In rabbits, DU‐176b also exerted a dose‐dependent antithrombotic effect (Fig. 5D), PT prolongation, and anti‐FXa activity in plasma (data not shown), significantly decreasing thrombi by 91% at 3 mg kg−1.

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Platinum wire‐induced venous thrombosis model [1]
Placement of a platinum wire in the rat vein induced formation of thrombi weighing 2.45 ± 0.38 mg on the surface of the wire. The thrombus formation was significantly reduced by Edoxaban/DU‐176b in a dose‐dependent manner (Fig. 6A). At a dose of 2.5 mg kg−1, DU‐176b reduced thrombus formation to 0.73 ± 0.21 mg. Similarly, FXa inhibition activity in plasma was significant and dose‐dependent (Fig. 6B).

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Effect on bleeding time [1]
Effect of Edoxaban/DU‐176b on tail bleeding time was not significantly different from control at 3 mg kg−1 (Table 3). At higher doses (10 and 30 mg kg−1), bleeding time was significantly prolonged (1.9‐fold) compared with the control.

Anti‐FXa activity of Edoxaban/DU‐176b [1]
To determine the inhibitory effect of DU‐176b on FXa activity, FXa was added to the mixture of DU‐176b or 5% dimethylsulfoxide (DMSO) control and a chromogenic substrate S‐2222 (250–1000 μm) in a reaction buffer (20 mm Tris–HCl, pH 7.4, 150 mm NaCl, 0.1% BSA). The final concentrations of FXa were as follows: human FXa (0.005 U mL−1, 0.7 nm), rabbit FXa (0.005 U mL−1, molarity unavailable), rat FXa (0.025 U mL−1, 10 nm) and cynomolgus monkey FXa (0.025 U mL−1, 3 nm). To measure amidolysis of S‐2222 by FXa, the absorbance at 405 nm was monitored with a microplate spectrophotometer SPECTRAmax 340 (Molecular Devices, Sunnyvale, CA, USA) at 30 °C for 10 min and the reaction velocity (mO.D./min) was obtained. The inhibition constant (Ki) values of DU‐176b were calculated by the Lineweaver–Burk plots and subsequent secondary plots.

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Inhibition of prothrombinase by Edoxaban/DU‐176b [1]
The inhibitory effect of DU‐176b on prothrombinase activity was examined using S‐2222 and the physiological substrate prothrombin, as described by Rezaie. Briefly, lipid vesicles were prepared by mixing of 1.2 mm phosphatidylcholine and 0.4 mm phosphatidylserine in chloroform, drying under vacuum, and resuspending in 9% sucrose. The suspension was sonicated and vesicles were extruded through filters of pore size 50–200 nm. Prothrombinase was formed by mixing human FXa (0.4 nm for S‐2222 and 0.2 pm for prothrombin), FVa (10 nm), CaCl2 (2.5 mm), and phosphatidylcholine/phosphatidylserine vesicles (25 μm) at 37 °C for 5 min. Amidolysis of S‐2222 (250–1000 μm) was measured as described for anti‐FXa activity of DU‐176b. Thrombin generation from prothrombin (7.8–250 nm) was measured as follows: the prothrombinase reaction proceeded for 3 min and was stopped by the addition of 10 mm EDTA. The activity of generated thrombin was measured by the amidolysis of its substrate S‐2238 and the concentration of thrombin was determined from a standard curve. The Ki values were calculated using the Lineweaver‐Burk plots and subsequent secondary plots.

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Specificity of serine protease inhibition of Edoxaban/DU‐176b [1]
The effects of DU‐176b on the following serine proteases (final concentrations) were examined: thrombin (0.03 U mL−1, 0.5 nm), FVIIa/sTF (2 nm/20 nm), FIXa (6.25 U mL−1, molarity unavailable), FXIa (0.25 nm), tPA (750 U mL−1, 20 nm), aPC (2.5 nm), trypsin (0.3 U mL−1, 1 nm), plasmin (0.004 U mL−1, 4 nm), and chymotrypsin (0.005 U mL−1, 2.5 nm). The enzymatic activities were assessed by the amidolysis of the following chromogenic substrates for correspondent protease: S‐2238 for thrombin, Spectrozyme fVIIa for FVIIa/sTF, Spectrozyme fIXa for FIXa, S‐2366 for FXIa and aPC, S‐2288 for tPA, S‐2251 for plasmin, S‐2222 for trypsin, and S‐2586 for chymotrypsin. The Ki values for these enzymes were determined as previously described.

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Anticoagulant activity in vitro [1]
The in vitro anticoagulant effects of Edoxaban/DU‐176b were studied. Clotting time (CT) in human, rat, cynomolgus monkey and rabbit plasma was measured using a microcoagulometer Amelung KC‐10A (MC Medical, Tokyo, Japan) and anticoagulant activity was expressed as the concentration of DU‐176b required to double CT (CT2), estimated by regression analysis from the dose‐response curves. Prothrombin time (PT) was measured by incubating plasma and DU‐176b (control; 4% DMSO/saline) for 1 min at 37 °C, followed by the addition of Thromboplastin C Plus (final concentration 0.25 U mL−1). Activated partial thromboplastin time (APTT) was measured by incubating plasma, DU‐176b and Platelin LS for 5 min at 37 °C, followed by the addition of CaCl2 (8.3 mm). Thrombin time (TT) was measured by incubating plasma and DU‐176b for 1 min at 37 °C, followed by the addition of human thrombin (4 U mL−1).

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Platelet aggregation [1]
Platelet‐rich plasma (PRP) was prepared from blood samples of healthy volunteers by centrifugation at 200 × g for 10 min at room temperature. To prepare washed platelets, PRP was then centrifuged at 600 × g for 10 min and the pellet was washed three times in Cor buffer (138 mm NaCl, 2.9 mm KCl, 10 mm Hepes‐NaOH, pH 7.3, 5.5 mm glucose, 12 mm NaHCO3) containing prostaglandin E1 (1 μm) and EDTA (10 mm). Washed platelets (2 × 108 platelets mL−1) were suspended in Cor buffer containing fibrinogen (1 mg mL−1) and CaCl2 (1 mm). EdoxabanDU‐176b was added to PRP or washed platelet suspension and incubated for 2 or 4 min at 37 °C. Platelet aggregation (>60%) was induced by the addition of collagen (0.8 μg mL−1), U46619 (0.7 μm) or ADP (5 μm) in PRP, and thrombin (0.08 U mL−1) in washed platelet suspension. Platelet aggregation was measured using an aggregometer PAM‐12C (MC Medical). Regression analysis was used to calculate the IC50 of DU‐176b.

Cell Viability Assay [1]
Cell Types: Human, rat, cynomolgus monkey and rabbit plasma; Human platelet
Tested Concentrations:
Incubation Duration: 1 and 5 minutes
Experimental Results: Antithrombin.

Animal/Disease Models: Male Slc: Wistar rats (210-240 g); Male New Zealand White rabbits(2.5-3.5 kg) (Both are venous stasis thrombosis model)[1].
Doses: 0.5, 2.5 and 12.5 mg/kg
Route of Administration: Oral administration; once
Experimental Results: Inhibited exogenous FXa activity. Antithrombotic.

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PD and PK studies of Edoxaban/DU‐176b after oral administration to rats and cynomolgus monkeys [1]
DU‐176b, DX‐9065a or the 0.5% methylcellulose vehicle were administered orally to fasted animals by gavage, and citrated blood samples were collected at 0.5, 1, 2 and 4 h in rats (n = 4 per dose group), and 0.5, 1, 2, 4, 8 and 24 h in cynomolgus monkeys (n = 6 per dose group) after administration. To measure FXa inhibition activity in plasma, a plasma sample (5 μL) was added to the reaction mixture of human FXa (0.01 U mL−1, 1.4 nm) and S‐2222 (300 μm). Amidolysis of S‐2222 was measured as described. The plasma concentrations of DU‐176b and DX‐9065a were measured by high‐performance liquid chromatography with tandem mass spectrometric detection.

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Antithrombotic effects of orally administered Edoxaban/DU‐176b [1]
Venous stasis thrombosis model in rats DU‐176b (0.5–12.5 mg kg−1) or 0.5% methylcellulose was orally administered to fasted rats (n = 8 per dose group). Venous thrombosis was induced 30 min after DU‐176b administration according to the method by Hladovec while the animals were anesthetized with thiopental sodium (100 mg kg−1, i.p.). Briefly, hypotonic NaCl solution (0.225%) was injected into the femoral vein (5 mL kg−1 min−1 for 2 min), and the inferior vena cava was ligated just below the left renal vein. Ten minutes later, the vena cava was ligated again 1.5 cm below the first ligature. The resulting thrombus was removed 1 h after the second ligation and its wet weight was measured. Blood samples were collected 29 min after DU‐176b dosing to measure PT and plasma FXa inhibition activity.

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Venous stasis thrombosis model in rabbits [1]
DU‐176b/Edoxaban (0.3–3 mg kg−1) or 0.5% methylcellulose was administered orally to fasted rabbits (n = 8 per dose group). The rabbits were anesthetized with urethane (2 g kg−1, i.p.) and venous thrombosis was induced 45 min after DU‐176b administration according to the method by Wessler et al. with some modifications. Recombinant human TF (0.05 μg 2‐mL−1 kg−1 for 30 s) was injected into the auricular vein, and 15 s later blood stasis was made in a 2‐cm segment of the jugular vein by a pair of ligations. The resulting thrombus was removed after 30 min, and its wet weight was measured.

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Platinum wire‐induced venous thrombosis model in rats [1]
Thrombus was induced by the insertion of a platinum wire (2 cm long) into the inferior vena cava of rats (n = 8 per dose group) just caudal to the left renal vein 30 min after oral administration of Edoxaban/DU‐176b (0.1–2.5 mg kg−1) or 0.5% methylcellulose according to the method of Lavelle and Iomhair. The resulting thrombus was fixed 1 h later with 1% glutaraldehyde. The wet weight of the thrombus was measured and blood samples were collected 29 min after DU‐176b dosing to measure plasma FXa inhibition activity.

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Effect of Edoxaban/DU‐176b on bleeding time [1]
Hemorrhage was induced 30 min following oral administration of DU‐176b (3–30 mg kg−1) or 0.5% methylcellulose and bleeding time was measured in a rat tail bleeding model. Briefly, an incision (1 mm deep) was made 4 cm from the tip of the tail. Blood was blotted every 15 s on filter papers, and bleeding time was defined as the time from the incision to the first arrest of bleeding. The maximum observation period was 30 min and longer bleeding time was assigned a value of 30 min.

Absorption, Distribution and Excretion
Following oral administration, peak plasma edoxaban concentrations are observed within 1-2 hours. Absolute bioavailability is 62%.
Edoxaban is eliminated primarily as unchanged drug in urine. Renal clearance (11 L/hour) accounts for approximately 50% of the total clearance of edoxaban (22 L/hour). Metabolism and biliary/intestinal excretion account for the remaining clearance.
The steady state volume of distribution is 107 L.
22 L/hr
/MILK/ There are no data on the presence of edoxaban in human milk ... . Edoxaban was present in rat milk. ...
Disposition is biphasic. The steady-state volume of distribution (Vdss) is 107 (19.9) L (mean (SD)). In vitro plasma protein binding is approximately 55%. There is no clinically relevant accumulation of edoxaban (accumulation ratio 1.14) with once daily dosing.
Administration of a crushed 60 mg tablet, either mixed into applesauce or suspended in water and given through a nasogastric tube, showed similar exposure compared to administration of an intact tablet.
Edoxaban is eliminated primarily as unchanged drug in the urine. Renal clearance (11 L/hour) accounts for approximately 50% of the total clearance of edoxaban (22 L/hour). Metabolism and biliary/intestinal excretion account for the remaining clearance.
Following oral administration, peak plasma edoxaban concentrations are observed within 1-2 hours. Absolute bioavailability is 62%. Food does not affect total systemic exposure to edoxaban. Savaysa was administered with or without food in the ENGAGE AF-TIMI 48 and Hokusai VTE trials.

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Metabolism / Metabolites
Edoxaban is not extensively metabolized by CYP3A4 resulting in minimal drug-drug interactions. However, it does interact with drugs that inhibit p-gp (p-glycoprotein), which is used to transport edoxaban across the intestinal wall. Unchanged edoxaban is the predominant form in plasma. There is minimal metabolism via hydrolysis (mediated by carboxylesterase 1), conjugation, and oxidation by CYP3A4. The predominant metabolite M-4, formed by hydrolysis, is human-specific and active and reaches less than 10% of the exposure of the parent compound in healthy subjects. Exposure to the other metabolites is less than 5% of exposure to edoxaban.
... All subjects received a single oral 60 mg edoxaban dose in period 1, and 7 days of 600 mg rifampin (2 x 300 mg capsules once daily) with a single oral edoxaban 60 mg dose administered concomitantly on day 7 in period 2. A 6-day washout period separated the treatments. Plasma concentrations of edoxaban and its metabolites M4 and M6 were measured, and limited assessments of pharmacodynamic markers of coagulation were performed. In total, 34 healthy subjects were enrolled; 32 completed the study. Coadministration of rifampin with edoxaban decreased edoxaban exposure but increased active metabolite exposure. Rifampin increased apparent oral clearance of edoxaban by 33% and decreased its half-life by 50%. Anticoagulant effects based on the prothrombin time (PT) and the activated partial thromboplastin time (aPTT) with and without rifampin at early time points were maintained to a greater-than-expected degree than with edoxaban exposure alone, presumably because of an increased contribution from the active metabolites. Edoxaban was well tolerated in this healthy adult population. Rifampin reduced exposure to edoxaban while increasing exposure to its active metabolites M4 and M6. PT and aPTT at early time points did not change appreciably; however, the data should be interpreted with caution.
Edoxaban and its low-abundance, active metabolite M4 are substrates of P-glycoprotein (P-gp; MDR1) and organic anion transporter protein 1B1 (OATP1B1), respectively, and pharmacological inhibitors of P-gp and OATP1B1 can affect edoxaban and M4 pharmacokinetics (PK). In this integrated pharmacogenomic analysis, genotype and concentration-time data from 458 healthy volunteers in 14 completed phase 1 studies were pooled to examine the impact on edoxaban PK parameters of allelic variants of ABCB1 (rs1045642: C3435T) and SLCO1B1 (rs4149056: T521C), which encode for P-gp and OATP1B1. Although some pharmacologic inhibitors of P-gp and OATP1B1 increase edoxaban exposure, neither the ABCB1 C3435T nor the SLCO1B1 T521C polymorphism affected edoxaban PK. A slight elevation in M4 exposure was observed among SLCO1B1 C-allele carriers; however, this elevation is unlikely to be clinically significant as plasma M4 concentrations comprise <10% of total edoxaban levels.
The predominant metabolite M-4, formed by hydrolysis, is human-specific and active and reaches less than 10% of the exposure of the parent compound in healthy subjects. Exposure to the other metabolites is less than 5% of exposure to edoxaban.
Unchanged edoxaban is the predominant form in plasma. There is minimal metabolism via hydrolysis (mediated by carboxylesterase 1), conjugation, and oxidation by CYP3A4.

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Biological Half-Life
The terminal elimination half-life of edoxaban following oral administration is 10 to 14 hours.
The terminal elimination half-life of edoxaban following oral administration is 10 to 14 hours.

Toxicity Summary
IDENTIFICATION AND USE: Edoxaban is a white to pale yellowish-white crystalline powder. It is used to reduce the risk of stroke and systemic embolism in patients with nonvalvular atrial fibrillation. It is also used for the treatment of deep vein thrombosis (DVT) and pulmonary embolism following 5 to 10 days of initial therapy with a parenteral anticoagulant. HUMAN STUDIES: Overdose of the drug increases the risk of bleeding. Edoxaban increases the risk of hemorrhage and can cause serious, potentially fatal, bleeding. Patients should be promptly evaluated if any manifestations of blood loss occur during therapy. The drug should be discontinued if active pathological bleeding occurs. However, minor or "nuisance" bleeding is a common occurrence in patients receiving any anticoagulant and should not readily lead to treatment discontinuance. Edoxaban and its human-specific metabolite, M-4 were not genotoxic in in vitro human lymphocytes micronucleus test. ANIMAL STUDIES: Edoxaban was not carcinogenic when administered daily to mice and rats by oral gavage for up to 104 weeks. Edoxaban showed no effects on fertility and early embryonic development in rats at doses of up to 1000 mg/kg/day. In a rat pre- and post-natal developmental study, edoxaban was administered orally during the period of organogenesis and through lactation day 20 at doses up to 30 mg/kg/day. Vaginal bleeding in pregnant rats and delayed avoidance response (a learning test) in female offspring were seen at 30 mg/kg/day. Embryo-fetal development studies were conducted in pregnant rats and rabbits during the period of organogenesis. In rats, no malformation was seen when edoxaban was administered orally at doses up to 300 mg/kg/day. Increased post-implantation loss occurred at 300 mg/kg/day, but this effect may be secondary to the maternal vaginal hemorrhage seen at this dose in rats. In rabbits, no malformation was seen at doses up to 600 mg/kg/day. Embryo-fetal toxicities occurred at maternally toxic doses, and included absent or small fetal gallbladder at 600 mg/kg/day, and increased post-implantation loss, increased spontaneous abortion, and decreased live fetuses and fetal weight at doses equal to or greater than 200 mg/kg/day. Edoxaban and its human-specific metabolite, M-4, were genotoxic in in vitro chromosomal aberration tests but were not genotoxic in the in vitro bacterial reverse mutation (Ames test), in in vivo rat bone marrow micronucleus test, in in vivo rat liver micronucleus test, and in in vivo unscheduled DNA synthesis tests.

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Hepatotoxicity
Edoxaban is associated with serum aminotransferase elevations greater than 3 times the upper limit of normal in 2% to 5% of treated patients. This rate is similar or lower than rates with warfarin or comparator arms. The elevations are generally transient and not associated with symptoms or jaundice. In premarketing studies, no instances of clinically apparent liver injury were reported, but there was little experience in large numbers of patients treated for extend periods of time. In large health care databases, the rate of liver injury has been somewhat less with edoxaban than rivaroxaban and apixaban, but the numbers of patients treated with edoxaban has been limited and the nature of the liver injury not described.
Likelihood score: D (possible race cause of clinically apparent liver injury).

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Effects During Pregnancy and Lactation
◉ Summary of Use during Lactation
Because no information is available on the use of edoxaban during breastfeeding and the drug is orally absorbable, an alternate drug is preferred, especially while nursing a newborn or preterm infant.
◉ Effects in Breastfed Infants
Relevant published information was not found as of the revision date.
◉ Effects on Lactation and Breastmilk
Relevant published information was not found as of the revision date.

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Protein Binding
In vitro plasma protein binding is ~55%.

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Interactions
Edoxaban, an oral direct factor Xa inhibitor, is in development for thromboprophylaxis, including prevention of stroke and systemic embolism in patients with atrial fibrillation (AF). P-glycoprotein (P-gp), an efflux transporter, modulates absorption and excretion of xenobiotics. Edoxaban is a P-gp substrate, and several cardiovascular (CV) drugs have the potential to inhibit P-gp and increase drug exposure. /The objective of the study was/ to assess the potential pharmacokinetic interactions of edoxaban and 6 cardiovascular drugs used in the management of AF and known P-gp substrates/inhibitors. Drug-drug interaction studies with edoxaban and CV drugs with known P-gp substrate/inhibitor potential were conducted in healthy subjects. In 4 crossover, 2-period, 2-treatment studies, subjects received edoxaban 60 mg alone and coadministered with quinidine 300 mg (n = 42), verapamil 240 mg (n = 34), atorvastatin 80 mg (n = 32), or dronedarone 400 mg (n = 34). Additionally, edoxaban 60 mg alone and coadministered with amiodarone 400 mg (n = 30) or digoxin 0.25 mg (n = 48) was evaluated in a single-sequence study and 2-cohort study, respectively. Edoxaban exposure measured as area under the curve increased for concomitant administration of edoxaban with quinidine (76.7%), verapamil (52.7%), amiodarone (39.8%), and dronedarone (84.5%), and exposure measured as 24 hr concentrations for quinidine (11.8%), verapamil (29.1%), and dronedarone (157.6%) also increased. Administration of edoxaban with amiodarone decreased the 24-hr concentration for edoxaban by 25.7%. Concomitant administration with digoxin or atorvastatin had minimal effects on edoxaban exposure. Coadministration of the P-gp inhibitors quinidine, verapamil, and dronedarone increased edoxaban exposure. Modest/minimal effects were observed for amiodarone, atorvastatin, and digoxin.
The oral direct factor Xa inhibitor edoxaban is a P-glycoprotein (P-gp) substrate metabolized via carboxylesterase-1 and cytochrome P450 (CYP) 3A4/5. The effect of rifampin-induced induction of P-gp and CYP3A4/5 on transport and metabolism of edoxaban through the CYP3A4/5 pathway was investigated in a single-dose edoxaban study. This was a phase 1, open-label, two-treatment, two-period, single-sequence drug interaction study in healthy adults. All subjects received a single oral 60 mg edoxaban dose in period 1, and 7 days of 600 mg rifampin (2 x 300 mg capsules once daily) with a single oral edoxaban 60 mg dose administered concomitantly on day 7 in period 2. A 6-day washout period separated the treatments. Plasma concentrations of edoxaban and its metabolites M4 and M6 were measured, and limited assessments of pharmacodynamic markers of coagulation were performed. In total, 34 healthy subjects were enrolled; 32 completed the study. Coadministration of rifampin with edoxaban decreased edoxaban exposure but increased active metabolite exposure. Rifampin increased apparent oral clearance of edoxaban by 33% and decreased its half-life by 50%. Anticoagulant effects based on the prothrombin time (PT) and the activated partial thromboplastin time (aPTT) with and without rifampin at early time points were maintained to a greater-than-expected degree than with edoxaban exposure alone, presumably because of an increased contribution from the active metabolites. Edoxaban was well tolerated in this healthy adult population. Rifampin reduced exposure to edoxaban while increasing exposure to its active metabolites M4 and M6. PT and aPTT at early time points did not change appreciably; however, the data should be interpreted with caution.
Verapamil increased peak plasma concentrations and systemic exposure of edoxaban by approximately 53%; pharmacokinetic parameters of verapamil were altered to only a slight extent. Dosage of edoxaban should be reduced when the drug is administered concomitantly with verapamil in patients with venous thromboembolism.
Quinidine increased peak plasma concentrations and systemic exposure of edoxaban by approximately 85 and 77%, respectively, but edoxaban did not affect pharmacokinetics of quinidine. Dosage of edoxaban should be reduced when the drug is administered concomitantly with quinidine in patients with venous thromboembolism.
For more Interactions (Complete) data for Edoxaban (19 total), please visit the HSDB record page.

[1]. DU-176b, a potent and orally active factor Xa inhibitor: in vitro and in vivo pharmacological profiles. J Thromb Haemost. 2008 Sep;6(9):1542-9.

Therapeutic Uses
Factor Xa Inhibitors
/CLINICAL TRIALS/ ClinicalTrials.gov is a registry and results database of publicly and privately supported clinical studies of human participants conducted around the world. The Web site is maintained by the National Library of Medicine (NLM) and the National Institutes of Health (NIH). Each ClinicalTrials.gov record presents summary information about a study protocol and includes the following: Disease or condition; Intervention (for example, the medical product, behavior, or procedure being studied); Title, description, and design of the study; Requirements for participation (eligibility criteria); Locations where the study is being conducted; Contact information for the study locations; and Links to relevant information on other health Web sites, such as NLM's MedlinePlus for patient health information and PubMed for citations and abstracts for scholarly articles in the field of medicine. Edoxaban is included in the database.
Savaysa is indicated to reduce the risk of stroke and systemic embolism (SE) in patients with nonvalvular atrial fibrillation (NVAF). /Included in US product label/
Savaysa is indicated for the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE) following 5 to 10 days of initial therapy with a parenteral anticoagulant. /Included in US product label/
For more Therapeutic Uses (Complete) data for Edoxaban (7 total), please visit the HSDB record page.

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Drug Warnings
/BOXED WARNING/ REDUCED EFFICACY IN NONVALVULAR ATRIAL FIBRILLATION PATIENTS WITH CRCL > 95 ML/MIN. Savaysa should not be used in patients with CrCL > 95 mL/min. In the ENGAGE AF-TIMI 48 study, nonvalvular atrial fibrillation patients with CrCL > 95 mL/min had an increased rate of ischemic stroke with Savaysa 60 mg once daily compared to patients treated with warfarin. In these patients another anticoagulant should be used.
/BOXED WARNING/ PREMATURE DISCONTINUATION OF SAVAYSA INCREASES THE RISK OF ISCHEMIC EVENTS. Premature discontinuation of any oral anticoagulant in the absence of adequate alternative anticoagulation increases the risk of ischemic events. If Savaysa is discontinued for a reason other than pathological bleeding or completion of a course of therapy, consider coverage with another anticoagulant as described in the transition guidance.
/BOXED WARNING/ SPINAL/EPIDURAL HEMATOMA. Epidural or spinal hematomas may occur in patients treated with Savaysa who are receiving neuraxial anesthesia or undergoing spinal puncture. These hematomas may result in long-term or permanent paralysis. Consider these risks when scheduling patients for spinal procedures. Factors that can increase the risk of developing epidural or spinal hematomas in these patients include: use of indwelling epidural catheters; concomitant use of other drugs that affect hemostasis, such as nonsteroidal anti-inflammatory drugs (NSAIDs), platelet inhibitors, other anticoagulants; a history of traumatic or repeated epidural or spinal punctures; a history of spinal deformity or spinal surgery; optimal timing between the administration of Savaysa and neuraxial procedures is not known. Monitor patients frequently for signs and symptoms of neurological impairment. If neurological compromise is noted, urgent treatment is necessar. Consider the benefits and risks before neuraxial intervention in patients anticoagulated or to be anticoagulated.
Safety and efficacy of edoxaban have not been evaluated in patients with mechanical heart valves or moderate to severe mitral stenosis; use of the drug is not recommended in such patients.
For more Drug Warnings (Complete) data for Edoxaban (18 total), please visit the HSDB record page.

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Pharmacodynamics
Administration of edoxaban results in prolongation of clotting time tests such as aPTT (activated partial thromboplastin time), PT (prothrombin time), and INR (international normalized ratio).

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Edoxaban is a monocarboxylic acid amide that is used (as its tosylate monohydrate) for the treatment of deep vein thrombosis and pulmonary embolism. It has a role as an anticoagulant, an EC 3.4.21.6 (coagulation factor Xa) inhibitor and a platelet aggregation inhibitor. It is a monocarboxylic acid amide, a chloropyridine, a thiazolopyridine and a tertiary amino compound. It is a conjugate base of an edoxaban(1+).

Edoxaban is a member of the Novel Oral Anti-Coagulants (NOACs) class of drugs, and is a rapidly acting, oral, selective factor Xa inhibitor. By inhibiting factor Xa, a key protein in the coagulation cascade, edoxaban prevents the stepwise amplification of protein factors needed to form blood clots. It is indicated to reduce the risk of stroke and systemic embolism (SE) in patients with nonvalvular atrial fibrillation (NVAF) and for the treatment of deep vein thrombosis (DVT) and pulmonary embolism (PE) following 5-10 days of initial therapy with a parenteral anticoagulant. Traditionally, warfarin, a vitamin K antagonist, was used for stroke prevention in these individuals but effective use of this drug is limited by it's delayed onset, narrow therapeutic window, need for regular monitoring and INR testing, and numerous drug-drug and drug-food interactions. This has prompted enthusiasm for newer agents such as dabigatran, apixaban, and rivaroxaban for effective clot prevention. In addition to once daily dosing, the benefits over warfarin also include significant reductions in hemorrhagic stroke and GI bleeding, and improved compliance, which is beneficial as many patients will be on lifelong therapy.

Edoxaban is a Factor Xa Inhibitor. The mechanism of action of edoxaban is as a Factor Xa Inhibitor.
Edoxaban is an oral, small molecule inhibitor of factor Xa which is used as an anticoagulant to decrease the risk of venous thromboses, systemic embolization and stroke in patients with atrial fibrillation, and as treatment of deep vein thrombosis and pulmonary embolism. Edoxaban has been linked to a low rate of serum aminotransferase elevations during therapy and to rare instances of clinically apparent acute liver injury.
Edoxaban is an orally active inhibitor of coagulation factor Xa (activated factor X) with anticoagulant activity. Edoxaban is administered as edoxaban tosylate. This agent has an elimination half-life of 9-11 hours and undergoes renal excretion.
EDOXABAN is a small molecule drug with a maximum clinical trial phase of IV (across all indications) that was first approved in 2015 and has 6 approved and 15 investigational indications. This drug has a black box warning from the FDA.

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Background: Factor Xa (FXa), a key serine protease that converts prothrombin to thrombin in the coagulation cascade, is a promising target enzyme for the prophylaxis and treatment of thromboembolic diseases. Edoxaban/DU-176b is a novel antithrombotic agent that directly inhibits FXa activity.

Objective: To evaluate the in vitro pharmacological profiles and in vivo effects of DU-176b in animal models of thrombosis and bleeding.

Methods: In vitro, FXa inhibition, specificity and anticoagulant activities were examined. Oral absorption was studied in rats and cynomolgus monkeys. In vivo effects were studied in rat and rabbit models of venous thrombosis and tail bleeding.

Results: DU-176b/Edoxaban inhibited FXa with Ki values of 0.561 nm for free FXa, 2.98 nm for prothrombinase, and exhibited >10 000-fold selectivity for FXa. In human plasma, DU-176b doubled prothrombin time and activated partial thromboplastin time at concentrations of 0.256 and 0.508 microm, respectively. DU-176b did not impair platelet aggregation by ADP, collagen or U46619. DU-176b was highly absorbed in rats and monkeys, as demonstrated by more potent anti-Xa activity and higher drug concentration in plasma following oral administration than a prototype FXa inhibitor, DX-9065a. In vivo, DU-176b dose-dependently inhibited thrombus formation in rat and rabbit thrombosis models, although bleeding time in rats was not significantly prolonged at an antithrombotic dose.

Conclusions: DU-176b/Edoxaban is a more potent and selective FXa inhibitor with high oral bioavailability compared with its prototype, DX-9065a. DU-176b represents a promising new anticoagulant for the prophylaxis and treatment of thromboembolic diseases. [1]

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In conclusion, Edoxaban/DU‐176b is a potent and highly selective direct FXa inhibitor and represents a remarkable improvement in the potency, selectivity and oral bioavailability compared with DX‐9065a. The present study demonstrates that DU‐176b has potential as an oral antithrombotic agent and a promising novel anticoagulant for the prophylaxis and treatment of thromboembolic diseases.[1]

C24H30CLN7O4S

548.06

547.176

C, 52.60; H, 5.52; Cl, 6.47; N, 17.89; O, 11.68; S, 5.85

480449-70-5

Edoxaban tosylate;480449-71-6; Edoxaban tosylate monohydrate; 1229194-11-9; Edoxaban-d6;1304701-57-2;Edoxaban hydrochloride;480448-29-1; 480449-70-5

10280735

White to off-white solid powder

1.4±0.1 g/cm3

Crystals as monohydrate from ethanol + water. MP: 245-48 (decomposes) /Edoxaban tosylate/

1.646

1.24

3

8

5

37

880

3

CN1CCC2=C(C1)SC(=N2)C(=O)N[C@@H]3C[C@H](CC[C@@H]3NC(=O)C(=O)NC4=NC=C(C=C4)Cl)C(=O)N(C)C

HGVDHZBSSITLCT-JLJPHGGASA-N

InChI=1S/C24H30ClN7O4S/c1-31(2)24(36)13-4-6-15(27-20(33)21(34)30-19-7-5-14(25)11-26-19)17(10-13)28-22(35)23-29-16-8-9-32(3)12-18(16)37-23/h5,7,11,13,15,17H,4,6,8-10,12H2,1-3H3,(H,27,33)(H,28,35)(H,26,30,34)/t13-,15-,17+/m0/s1

N'-(5-chloropyridin-2-yl)-N-[(1S,2R,4S)-4-(dimethylcarbamoyl)-2-[(5-methyl-6,7-dihydro-4H-[1,3]thiazolo[5,4-c]pyridine-2-carbonyl)amino]cyclohexyl]oxamide

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)