HK1093900B - Novel association consisting of an anti-atherothrombotic agent and of a platelet antiaggregating agent - Google Patents

Description

New combination of an anti-atherothrombotic agent and an anti-platelet aggregation agent

The present invention relates to a novel combination of an anti-atherothrombotic agent and an anti-platelet aggregation agent, and to pharmaceutical compositions containing them.

More particularly, the present invention relates to a combination of a specific TP receptor antagonist and clopidogrel.

Thromboxane A₂(TXA₂) Is an unstable metabolite of arachidonic acid and is involved in the pathogenesis of many cardiovascular diseases. Thromboxane A₂Is a strong platelet activator, and is also a strong vasoconstrictor with cell proliferative and pro-adhesive properties.

TXA₂And other arachidonic acid metabolites, such as endoperoxides (PGGG)₂-PGH₂)、HETES and isoprostanes, both exhibit their effects via a co-receptor known as the TP receptor (thromboxane-prostaglandin-endoperoxide).

Recently, a great deal of research has been carried out with the aim of preventing the overproduction of thromboxane A in the cardiovascular and neurovascular system₂A related phenomenon. Among such antagonists, those described in the specification of patent EP 648741 were found to be strong and selective antagonists of the TP receptor, which are active and have a long duration of action when administered by the oral route.

More particularly, the applicant has found that the compounds of formula (I) (a) and their pharmaceutically acceptable salts, in racemic form or in optically pure isomeric form, are strong anti-atherothrombotic agents:

compound (A) is a specific TP receptor antagonist, more particularly, a thromboxane A₂And prostaglandin-endoperoxides (PGGs)₂-PGH₂) Specific antagonists of the receptor, thus conferring a potent atherothrombotic effect on the compound.

Generally, after rupture of an atherosclerotic plaque, thrombosis results from the interaction of circulating platelets with collagen of the vascular endothelial lining exposed to the blood stream. This phenomenon is called atherothrombosis.

Collagen is present in the basal layer of the vessel wall and is a determinant of atheromatous lesion thrombosis in humans and animals.

Platelets adhere to collagen fibers via collagen receptors and are also associated with platelet adhesion, activation and aggregation.

Platelet activation is accompanied by the release of two major agonists, ADP and thromboxane a₂They bind to the respective receptors (P2Y, TP) on adjacent platelets, resulting in enhanced adhesion and platelet aggregation.

ADP is also present in the blood as a circulating medium, and thromboxane A₂Is a strong secondary mediator which is produced from arachidonic acid by the enzyme cyclooxygenase 1 in activated platelets.

Thromboxane A₂Not only promotes thrombosis, but also induces dysfunction of the vascular wall (vasoconstriction), promotes vascular wall hyperplasia and inflammatory infiltration.

Among the antiplatelet therapies currently available, aspirin inhibits the treatment of thromboxane A₂Platelets are produced while clopidogrel inhibits ADP-induced platelet aggregation.

ADP and thromboxane A₂Plays an important complementary role in arterial thrombosis.

Compound A is obtained by blocking thromboxane A₂And other TP receptor ligands, regardless of source, platelet and platelet.

It is also through inhibition by thromboxane A₂Induced vasoconstriction and works by fighting endothelial dysfunction and proliferation of the vessel wall and inflammation.

The applicant has now found that the combination of compound a with clopidogrel has a surprising antithrombotic synergistic effect in humans.

In fact, since compound a acts on platelets with completely different aggregation pathways than clopidogrel, it is particularly advantageous to combine these two compounds in order to obtain a new therapeutic approach.

The applicant has surprisingly found that the combination of compound a with clopidogrel has a significant synergistic effect with respect to activity, which is not suggested from any existing literature. The improvement of the antithrombotic effect of this combination product can be evaluated ex vivo by the inhibition of collagen-induced platelet aggregation.

This test shows that the antithrombotic activity of compound a is enhanced in the presence of clopidogrel and increases in an extremely significant and completely unpredictable manner. Furthermore, the combination product has good acceptability.

In the combination of the present invention, compound a and clopidogrel may be in the form of pharmaceutically acceptable salts.

Among the addition salts of compound a, there may be mentioned addition salts with pharmaceutically acceptable bases, such as sodium salt, potassium salt, tert-butylamine salt, diethylamine salt and the like, but not limited thereto.

The preferred salt is the sodium salt.

Among the addition salts of clopidogrel, the hydrogen sulfate is preferred.

In the combination of the invention, compound a preferably has the absolute configuration (R).

The invention also relates to a pharmaceutical composition containing a combination product of compound a and clopidogrel or a pharmaceutically acceptable salt thereof, which may also contain one or more suitable inert non-toxic excipients, if desired.

Among the pharmaceutical compositions of the invention, mention may be made more particularly of those suitable for oral, parenteral or nasal administration, which are tablets or lozenges, sublingual tablets, gelatin capsules, suppositories, creams, ointments, dermal gels, etc.

The dosage employed may vary depending on the nature and severity of the condition, the mode of administration and the age and weight of the patient.

In the composition of the present invention, the amount of the active ingredient is 1 to 300mg of compound a, 10 to 600mg of clopidogrel.

Thus, the compositions of the invention may be used to treat cardiovascular diseases involving TP receptor activation, as well as to treat the consequences of such diseases. Such conditions include, but are not limited to, acute coronary syndrome, stable or unstable angina, endothelial dysfunction, vascular disease associated with atherosclerosis, hypertension, diabetes and heart failure, and also for the prevention and treatment of vascular, cardiovascular or neurovascular system diseases, in particular thromboembolic diseases associated with atherosclerosis, atrial fibrillation, as well as thromboembolic diseases associated with invasive surgery (angioplasty, stenting, bypass surgery, catheter, etc.) in cardiology, neurology, vascular pathology and radiology.

Inhibition of collagen-induced platelet aggregation

18 volunteers, who had been treated with clopidogrel 75mg for 7 days, were orally administered 10mg of compound a and 75mg of clopidogrel daily for three consecutive days. The therapeutic effect of the combination product of compound a and clopidogrel was compared with the effect of taking compound a and clopidogrel separately.

During the experiment, platelet aggregation on citric acid platelet rich plasma (PRPc) was measured using a platelet aggregation meter, and the percentage inhibition of in vitro collagen (5. mu.g/ml) induced platelet aggregation was calculated.

The results obtained were as follows:

35% inhibition by administration of compound a itself,

clopidogrel itself achieved 11% inhibition upon administration,

the administration of the combination of compound a and clopidogrel resulted in 62% inhibition.

These results clearly show that the administration of a combination of the two compounds has a synergistic effect on collagen-induced platelet aggregation. The anti-aggregation effect produced by this combination product is higher than the sum of the effects of the two products when taken separately. This effect has never been mentioned in the literature.

The above results indicate that such a combination product can be effective in the treatment of acute or chronic conditions (acute treatment or secondary prevention of neurovascular or cardiovascular diseases) where an enhanced antithrombotic effect associated with vascular effects is required.

Claims (12)

1. A combination of a compound (a) of formula (I) below or one of its pharmaceutically acceptable salts and clopidogrel or one of its pharmaceutically acceptable salts, optionally in the form of optical isomers:

2. combination according to claim 1, characterized in that compound (a) is in the form of the optical isomer of the (R) configuration.

3. Combination according to claim 1, characterized in that compound (a) is in the form of the sodium salt.

4. Combination according to any one of claims 1, 2 and 3, characterized in that clopidogrel is in the form of the bisulfate salt.

5. A pharmaceutical composition containing, as active ingredients, compound (a) or one of its pharmaceutically acceptable salts and clopidogrel or one of its pharmaceutically acceptable salts, optionally in the form of optical isomers, and also containing one or more pharmaceutically acceptable inert excipients or carriers.

6. Pharmaceutical composition according to claim 5, characterized in that compound (A) is in the form of the (R) configuration optical isomer.

7. Pharmaceutical composition according to claim 5, characterized in that compound (A) is in the form of the sodium salt.

8. The pharmaceutical composition according to any one of claims 5, 6 and 7, characterized in that clopidogrel is in the form of the bisulfate salt.

9. Pharmaceutical composition according to any one of claims 5 to 7, characterized in that the amount of active ingredient is 1 to 300mg of Compound A, 10 to 600mg of clopidogrel, respectively.

10. A pharmaceutical composition according to any one of claims 5 to 7 for use in the treatment of cardiovascular diseases involving activation of the TP receptor and also for the treatment of the consequences of said diseases.

11. The pharmaceutical composition according to claim 10, for the treatment of acute coronary syndrome, stable or unstable angina pectoris, endothelial dysfunction, vascular diseases associated with atherosclerosis, hypertension, diabetes and heart failure, and for the prophylaxis and treatment of vascular, cardiovascular or neurovascular diseases and thromboembolic diseases.

12. The pharmaceutical composition according to claim 11, for the prevention and treatment of thromboembolic diseases associated with atherosclerosis, atrial fibrillation, as well as thromboembolic diseases associated with invasive surgical procedures in cardiology, neurology, vascular pathology, and radiology.