Hepatic protection, antithrombotic, anti-inflammatory, profibrinolytic, anti-ischemic

By agonism at adenosine A1 and A2 receptors, defibrotide sodium limits the release of inflammatory mediators and decreases the production of intracellular adhesion molecule-1, which in turn has anti-inflammatory effects[1]. By raising prostaglandin I2 and E2 synthesis and suppressing plasminogen activator inhibitor type 1 activity, defibrotide sodium prevents platelet aggregation and promotes fibrinolysis[1]. Moreover, defibrotide sodium promotes the synthesis of tissue factor pathway inhibitor while decreasing tissue factor production, which reduces the activation of the extrinsic coagulation cascade and fibrin deposition[1]. Tumor necrosis factor α-mediated endothelial cell damage as well as fludarabine-induced activation and death are prevented by defibrotide sodium[1].

When intraperitoneally (ic) administered before intravenous (ic) thrombin (100 μg/kg), Defibrotide sodium (64 mg/kg bolus plus 64 mg/kg/h for 1 h) dramatically lowers the capacity of thrombin to generate cranial thromboembolism in rabbits[2]. Intravenous (iv) defibrotide (64 mg/kg bolus plus 64 mg/kg/h for 1 h) administered intravenously (iv) prior to intravenous (iv) thrombin administration in rabbits greatly reduces the reversible accumulation of radiolabelled platelets into the thoracic circulation[2]. Pretreatment with defibrotide (150-175 mg/kg, IV) considerably reduces the majority of animals that die after receiving an intravenous injection of human thrombin (1250 μg/kg) in mice[2].

Defibrotide can be dissolved in saline for in vivo studies [2]

---

1. Administration of bovine thrombin (100 u kg-1) into the carotid artery of rabbits induces a sustained accumulation of 111 Indium-labelled platelets within the cranial vasculature over the subsequent 3 h.
2. Intracarotid (i.c.) administration of defibrotide (64 mg kg-1 bolus plus 64 mg kg-1 h-1 for 1 h) prior to i.c. thrombin (100 u kg-1) significantly reduces the ability of thrombin to induce cranial thromboembolism in rabbits.
3. Intravenous (i.v.) administration of thrombin (20 u kg-1) in rabbits induces a reversible accumulation of radiolabelled platelets into the thoracic circulation which is significantly reduced by i.v. administration of defibrotide (64 mg kg-1 bolus plus 64 mg kg-1 h-1 for 1 h) prior to i.v. thrombin. In contrast, platelet accumulation in response to adenosine diphosphate (ADP; 20 micrograms kg-1, i.v.) or platelet activating factor (PAF; 50 ng kg-1, i.v.) is not significantly affected by this treatment.
4. Intravenous administration of the nitric oxide (NO)-synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 10 mg kg-1) potentiates platelet accumulation induced by low dose thrombin (10 u kg-1, i.v.) within the pulmonary vasculature of rabbits. The potentiated response is significantly abrogated following pretreatment with defibrotide (64 mg kg-1 bolus plus 64 mg kg-1 h-1 for 1 h, i.v.).
5. Intravenous injection of human thrombin (1250 u kg-1) to mice induces death within the majority of animals which is significantly reduced by pretreatment with defibrotide (150-175 mg kg-1, i.v.). In contrast, death induced by i.v. collagen (1.25 mg kg-1) plus adrenaline (75 microg kg-1) is not significantly affected by defibrotide pretreatment.
6. The inhibitory effect of defibrotide in mice is abolished following concomitant treatment with the inhibitor of fribrinolysis, tranexamic acid (100 mg kg-1, i.v.), but is unaffected following treatment with the cyclo-oxygenase inhibitor, aspirin (300 mg kg-1, i.p.).
7. The protective effect of defibrotide against thrombin-induced thromboembolism in the mouse is potentiated by recombinant tissue-plasminogen activator (rt-PA; 1 mg kg-1, i.v.) or unfractionated heparin (10 u kg-1, i.v.) administration.
8. The results suggest that defibrotide may possess antithrombotic activity on thrombin-induced thromboembolism which, at least in the mouse, may be partially mediated via induction of the fibrinolytic pathway[2].

Absorption, Distribution and Excretion
Bioavailability is 58-70% following oral administration, compared to parenteral forms (i.v. and i.m. = 100%).

---

Biological Half-Life
t1/2-alpha = minutes (10-20 minutes in rat); t1/2-beta = a few hours

Hepatotoxicity
Defibrotide therapy has not been linked to serum aminotransferase elevations or with instances of clinically apparent liver injury separate from the features of SOS for which it is given. In a trial of defibrotide as prophylaxis against SOS conducted in 356 children undergoing HCT, rates of severe adverse events such as hemorrhage, gastrointestinal complaints and liver injury were similar in those receiving defibrotide as in untreated children.
Likelihood score: E (unlikely cause of clinically apparent acute liver injury).

[1]. Defibrotide: An Oligonucleotide for Sinusoidal Obstruction Syndrome. Ann Pharmacother. 2018 Feb;52(2):166-174.

[2]. The effect of defibrotide on thromboembolism in the pulmonary vasculature of mice and rabbits and in the cerebral vasculature of rabbits. Br J Pharmacol. 1993 Dec;110(4):1565-71.

Defibrotide is the sodium salt of a mixture of single-stranded oligodeoxyribonucleotides derived from porcine mucosal DNA. It has been shown to have antithrombotic, anti-inflammatory and anti-ischemic properties (but without associated significant systemic anticoagulant effects). It is marketed under the brand names Dasovas (FM), Noravid, and Prociclide in a variety of countries. In the USA it is was approved in March, 2016 as Defitelio.
Defibrotide is a complex mixture of single stranded polydeoxyribonucleotides derived from porcine intestinal mucosa that has antithrombotic and profibrinolytic activity and is used in the treatment of severe sinusoidal obstruction syndrome (SOS) after hematopoietic cell transplantation (HCT). Defibrotide is used in patients with severe liver injury and has not been associated with worsening of serum aminotransferase elevations during therapy and has not been linked to cases of clinically apparent, idiosyncratic liver injury.
Defibrotide is a mixture of single-stranded oligodeoxyribonucleotides derived from the intestinal mucosa of pigs, with anti-thrombotic, thrombolytic, and fibrinolytic activities. Upon administration, and although the exact mechanism of action has yet to be fully elucidated, defibrotide induces the release of prostaglandin I2 (PGI2), E2 (PGE2), and prostacyclin and reduces the expression of adhesion molecules on endothelial cells. This relaxes the smooth muscle of blood vessels and prevents platelets from adhering to each other and to the endothelium. This protects the endothelium lining bloods vessels. Defibrotide increases tissue plasminogen activator (t-PA) and decreases plasminogen activator inhibitor-1 activity. This increases the activity of plasmin, prevents blood clot formation and dissolves blood clots.
See also: Defibrotide Sodium (annotation moved to).

---

Drug Indication
Indicated for the treatment of severe hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), with renal or pulmonary dysfunction following hematopoietic stem-cell transplantation (HSCT).
FDA Label

---

Mechanism of Action
The drug appears to prevent the formation of blood clots and to help dissolve blood clots by increasing levels of prostaglandin I2, E2, and prostacyclin, altering platelet activity, increasing tissue plasminogen activator function, and decreasing activity of tissue plasminogen activator inhibitor. Prostaglandin I2 relaxes the smooth muscle of blood vessels and prevents platelets from adhering to each other. Prostaglandin E2 at certain concentrations also inhibits platelet aggregation. Moreover, the drug provides additional beneficial anti-inflammatory and antiischemic activities as recent sudies have shown. It is yet unclear, if the latter effects can be utilized clinically (e.g., treatment of ischemic stroke).

C20H21N4O6P

444.377

444.119

83712-60-1

83712-60-1(sodium);1118915-78-8 (free acid);1402907-09-8 (disodium);1118915-79-9 (monosodium);

135565962

Powder form

1.8

4

7

5

31

773

0

P(=O)(O)(O)OC1=CC(=C(C=C1C(C)C)C1=NNC(N1C1C=CC2=C(C=CN2C)C=1)=O)O

JNWFIPVDEINBAI-UHFFFAOYSA-N

InChI=1S/C20H21N4O6P/c1-11(2)14-9-15(17(25)10-18(14)30-31(27,28)29)19-21-22-20(26)24(19)13-4-5-16-12(8-13)6-7-23(16)3/h4-11,25H,1-3H3,(H,22,26)(H2,27,28,29)

[5-hydroxy-4-[4-(1-methylindol-5-yl)-5-oxo-1H-1,2,4-triazol-3-yl]-2-propan-2-ylphenyl] dihydrogen phosphate

Defibrotide;1118915-78-8; UNII-E1942E7K32; STA-1474; UNII-E1942E7K32; 5-Hydroxy-2-isopropyl-4-(4-(1-methyl-1H-indol-5-yl)-5-oxo-4,5-dihydro-1H-1,2,4-triazol-3-yl)phenyl dihydrogen phosphate; E1942E7K32; Defibrotide sodium

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)

Soluble in H2O or saline (e.g. >5 mg/mL)

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.

---

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).

View More

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)

---

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).

View More

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

---

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.

---

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