WO2007088554A1 - A pharmaceutical composition for treatment of vulnerable atherosclerotic plaque and inhibition of thrombosis, adhesion molecules and inflammation - Google Patents

Abstract

This invention relates to a pharmaceutical composition for treatment of vulnerable atherosclerotic plaque and inhibition of thrombosis, adhesion molecules and inflammation, and for enhancing endothelial regeneration. A composition for local delivery comprises fucans and / or its functional equivalents having a molecular weight in the range of 8 kDa to less than 30 kDa either alone or in combination with at least one drug capable of synergistically acting therewith such as hormones, genetic material, peptides, antithrombotic agents, oxidative stress inhibitors, agents to decrease plaque size, statins, HDL-cholesterol mimetic agents, fibrinolytic agents, anti-inflammatory agents, and antiproliferative agents. This composition is administered directly and locally through conventional drug administering means and devices such as a stent. In another embodiment of the invention, fucans may be delivered locally by means of any intravascular device (implantable or nonimplantable) for the prevention of restenosis following arterial injury.

Description

TITLE OF THE INVENTION

A pharmaceutical composition for treatment of vulnerable atherosclerotic plaque and inhibition of thrombosis, adhesion molecules and inflammation.

FIELD OF THE INVENTION

The present invention relates generally to a pharmaceutical composition for the treatment of vulnerable plaque in a patient with established atherosclerosis, and specifically to the prevention of thrombosis, inhibition of adhesion molecules and inflammation, and enhancing endothelial regeneration by the local delivery of fucans in the treatment of vulnerable atherosclerotic plaque. In another embodiment, the present invention also relates to the local delivery of fucans by means of any intravascular device (implantable or nonimplantable) for the prevention of restenosis following arterial injury.

BACKGROUND OF THE INVENTION

Each year, more than 1 million patients with atherosclerosis in the United States and over 19 million patients worldwide experience a sudden cardiac event (acute coronary syndromes and/or sudden cardiac death) (Myerburg RJ, et al. Frequency of sudden cardiac death and profiles of risk. Am J Cardiol. 1997; 80: 10F- 19F). The underlying cause in the vast majority of such patients is a vulnerable plaque. Established plaques and complicated plaques are susceptible to rupture, erosion, or sudden expansion resulting in the sudden cardiac event.

Long-term treatment with oral medications such as statins, have been reported to stabilize vulnerable plaque, but acute coronary events occur although less frequently, despite medication. Furthermore, several weeks of treatment with the oral medication is needed before benefits become apparent.

Given the potential serious clinical consequences of a vulnerable plaque, there is a need for a treatment of vulnerable plaques that is effective and ensures that the benefits accrue immediately after treatment.

The present invention proposes to address the need for such a treatment for vulnerable plaque.

U. S. Patent Nos. 5833651 and 6228845 to Donovan et al. describe the application of fucoidan as a polymer for coating the lumen-exposed surface of an intravascular stent as a barrier to minimize diffusion of DNA into the lumen of the artery (DNA is the active agent, and is coated on to the outer surface of the stent on another polymer). U. S. Patent Application No. 20050186243 to Hunter William L et al. describes the application of fucoidan as a carrier to deliver active fibrosing agents (such as silk, fibrin, fibronectin, collagen, etc.) to a vulnerable plaque.

U. S. Patent No. 5321133 to Colliec et al. and U. S. Patent No. 5948405 to Cedro et al. describe the anti-thrombotic properties of fucoidan administered by parenteral, oral or topical route. U. S. Patent No. 6828307 to Colliec- Jouault et al. describes the use of fucan for treatment of systemic arterial thrombosis by intravenous or subcutaneous administration. The same patent also describes the application of fucan delivered locally by balloon catheters for restenosis prevention following balloon angioplasty.

U. S. Patent Nos. 6410587 and 6734208 to Grainger et al. describe the local delivery of agents (one of which is fucoidan) in the treatment of a mammal having, or at risk of, a vascular indication which is associated with TGF-beta deficiency such as for plaque stabilization in atherosclerosis by a method of increasing the levels of TGF- beta. However, it is worthy of note that, current evidence has clearly demonstrated that TGF-beta deficiency is associated with only the preliminary stage of atherosclerosis such as fatty streaks, whereas, established plaques and complicated plaques are associated with intrinsically high levels of TGF-beta (Panutsopulos D, et al. Protein and mRNA expression levels of VEGF-A and TGF-betal in different types of human coronary atherosclerotic lesions. Int J MoI Med 2005;15:603-10). In fact, the intrinsically high levels of TGF-beta in established plaques and complicated plaques have been implicated to lead to progression of atherosclerosis and complications ( Panutsopulos D, et al. Protein and mRNA expression levels of VEGF- A and TGF-betal in different types of human coronary atherosclerotic lesions. Int J MoI Med 2005;15:603-10; Ross R. Atherosclerosis - an inflammatory disease. N Engl J Med 1999;340: 115-26). Therefore, the U. S. Patent Nos. 6410587 and 6734208 to Grainger et al. would apply only to the treatment of the preliminary stage of atherosclerosis such as fatty streaks (which is associated with a TGF-beta deficiency). The U. S. Patent Nos. 6410587 and 6734208 to Grainger et al. would not apply to the treatment of established plaques and complicated plaques which are associated with intrinsically high levels of TGF-beta. It is well known to those skilled in the art that fatty streaks (which is associated with a TGF-beta deficiency) are not vulnerable plaques, and that, established plaques and complicated plaques (which are associated with intrinsically high levels of TGF-beta) are considered to be vulnerable plaques (Ross R. Atherosclerosis - an inflammatory disease. N Engl J Med 1999;340: 115-26).

Furthermore, importantly, none of the patents or patent applications envisages the application of local delivery of fucoidan for inhibiting thrombosis, for inhibiting adhesion molecules, and for stimulating endothelial regeneration in the treatment of vulnerable plaque. This clearly indicates that the use of local delivery of fucoidan was not known over the art of record for inhibiting thrombosis, for inhibiting adhesion molecules, and for stimulating endothelial regeneration in the treatment of vulnerable plaque.

The present invention describes treatment of vulnerable plaque by the local delivery of fucoidan for inhibiting thrombosis, for inhibiting adhesion molecules, and for stimulating endothelial regeneration. This new use is novel and non-obvious over the art of record. SUMMARY OF THE INVENTION

Fucans (fucoidan, sulfated fucans, fucoidin), and exemplified by fucoidan, have properties of inhibition of thrombosis, inhibition of adhesion molecules thereby suppressing inflammation, and of enhancing endothelial regeneration. These properties make fucans an ideal candidate for the treatment, by local delivery, of vulnerable plaque in established atherosclerosis. Additionally, fucans have properties of inhibiting vascular smooth muscle cell proliferation. This effect, along with their ability to inhibit inflammation and to enhance endothelial regeneration, may be utilized to reduce restenosis after arterial injury by delivering fucans locally by means of any intravascular device (implantable or nonimplantable).

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Vulnerable plaques are atherosclerotic plaques with high likelihood of thrombotic complications and rapid progression. These have been well described in the literature as, (1) rupture-prone plaque with large lipid core and thin fibrous cap infiltrated by macrophages, (2) ruptured plaque with subocclusive thrombus and early organization, (3) erosion-prone plaque with proteoglycan matrix in a smooth muscle cell-rich plaque, (4) eroded plaque with subocclusive thrombus, (5) plaque with intra- plaque hemorrhage, (6) plaque with calcific nodule protruding into the vessel lumen, and (7) chronically stenotic plaque with severe calcification, old thrombus, and eccentric lumen (Naghavi M, et al. From vulnerable plaque to vulnerable patient. Circulation 2003;108:1664).

As in situ thrombosis is a vital feature in the pathogenesis of vulnerable plaque and its complications, agents with anti-thrombotic activity play a crucial role in the treatment of vulnerable plaque. Fucans are potent anti-thrombotic agents. Fucans exert their anti-thrombotic effect by catalysis of the serpins anti-thrombin and heparin cofactor II (Millet J, et al. Anti-thrombotic and anticoagulant activities of a low molecular weight fucoidan by the subcutaneous route. Thromb Haemost 1999;81:391- 5). Fucans release tissue factor pathway inhibitor from endothelial cells, further contributing to their anti-thrombotic activity (Giraux JL, et al. Fucoidan, as heparin, induces tissue factor pathway inhibitor release from cultured human endothelial cells. Thromb Haemost 1998;80:692-5).

Erosion of endothelial lining with resultant loss of endothelial cells is an important histological feature of vulnerable plaque. Regeneration of the damaged endothelial cell lining is an important constituent in the treatment of vulnerable plaque. Fucans have been demonstrated in experimental studies to stimulate the growth and migration of endothelial cells (Giraux JL, et al. Modulation of human endothelial cell proliferation and migration by fucoidan and heparin. Eur J Cell Biol 1998;77:352-9; Matou S, et al. Effect of fucoidan on fibroblast growth factor-2 induced angiogenesis in vitro. Thromb Res 2002;106:213-21; Matsubara K, et al. Effects of middle molecular weight fucoidans on in vitro and ex vivo angiogenesis of endothelial cells. Int J MoI Med 2005; 15:695-9).

In addition to thrombosis and endothelial erosion, vulnerable plaques demonstrate a high local concentration of adhesion molecules such as P-selectin (Tenaglia AN, et al. Levels of expression of P-selectin, E-selectin and intercellular adhesion molecule- 1 in coronary atherectomy specimens from patients with stable and unstable angina pectoris. Am J Cardiol. 1997;79:742-747) crucial for the recruitment of inflammatory cells. Inflammatory cell infiltration plays an important role in pathogenesis of a vulnerable plaque (Ross R. Atherosclerosis - an inflammatory disease. N Engl J Med 1999;340: 115-26; Tiong AY, et al. Inflammation and coronary artery disease. Am Heart J 2005; 150: 11-8). Fucans exert their anti-inflammatory effect by binding to P-selectin and potently inhibiting P-selectin function (Berteau O, et al. Sulfated fucans, fresh perspectives: structures, functions, and biological properties of sulfated fucans and an overview of enzymes active towards this class of polysaccharides. Glycobiology 2003;13:29R-40R). Systemic administration of fucoidan may not achieve a local concentration of the agent sufficient to produce a significant effect. Administration of higher systemic doses to produce the desired effect may result in intolerance or adverse effects. Locally delivering fucoidan directly to the desired site would eliminate any adverse effects associated with systemic administration. As the fucoidan is delivered directly to the desired site of action, the dose required to produce the desired effect is also markedly reduced, further decreasing the incidence of any possible adverse effect.

The molecular weight of fucoidan intended to be used in the present invention will range from 8 kDa to less than 30 kDa. The fucoidan may be administered locally . in a dose ranging from 0.1 mg/kg to 50 mg/kg. The dosage of fucoidan intended to be delivered locally may be determined by the attending physician taking into account factors such as, body weight of the patient, the number of vulnerable plaques to be treated, and other parameters. In experimental studies no adverse effects were observed when doses of 300 mg/kg per day of fucoidan were administered systemically for as long as six months (Li N, et al. Toxicological evaluation of fucoidan extracted from Laminaria japonica in Wistar rats. Food Chem Toxicol 2005 ;43:421-6). The dose of fucoidan intended to be delivered locally in the present invention is only a fraction of the dose used for systemic administration in animal studies, and, more importantly, will be administered to the patient only at the time of the procedure, and not everyday.

In an embodiment of the invention, the local delivery of fucans at the desired site can be performed with the help of a variety of drug delivery catheters. The use of various drug delivery catheters for local drug delivery is well described and is known to those skilled in the art (Chandrasekar B, et al. Local delivery in coronary artery disease: an overview for the interventional cardiologist. Indian Heart Journal 1999; 51: 21-6). These include, but are not limited to a double-balloon catheter, porous balloon catheter, infusion sleeve catheter, coil balloon catheter (Dispatch catheter), iontophoretic balloon catheter, the infiltrator, and the hydrogel-coated balloon catheter. In one embodiment, an aqueous solution of fucans (1 ml to 10 ml) may be delivered using designated drug delivery catheters. In another embodiment, fucans can be delivered in the form of a viscous material or gel using a hydrogel-coated balloon catheter. In another embodiment, fucans can be delivered using iontophoresis. The fucans may also be administered in the form of a suspension, such as a suspension of bio-degradable polymers releasing fucans.

In yet another embodiment of the invention, fucans may be delivered locally at the desired site by means of any intravascular implantable device, such as a stent. The drug-eluting stent may be metallic, made of metal alloy, non-metallic, or biodegradable. The fucan may be released from the drug-eluting stent either with or without the use of polymers or other bio-degradable materials as drag carriers. Alternatively, the fucan may be released directly from a bare drug-eluting stent. The use of drug-eluting stents for local drug delivery is well known to those skilled in the art (de Scheerder I, et al. The Elutes clinical study: 12 -month clinical follow-up. Circulation 2002;106;II-394; Park SJ, et al. A paclitaxel-eluting stent for the prevention of coronary restenosis. N Engl J Med 2003;348:1537-45; Moses JW, et al. Sirolimus-eluting stents versus standard stents in patients with stenosis in a native coronary artery. N Engl J Med 2003 ;349: 1315-23; Colombo A, et al. Randomized study to assess the effectiveness of slow- and moderate-release polymer-based paclitaxel-eluting stents for coronary artery lesions. Circulation 2003; 108:788-94).

Accordingly the present invention provides a pharmaceutical composition for treatment of vulnerable atherosclerotic plaque and for the inhibition of thrombosis, adhesion molecules and inflammation, and for enhancing endothelial regeneration comprises fucans and / or its functional equivalents having a molecular weight in the range of 8 kDa to less than 30 kDa either alone or in combination with a drug capable of synergistically acting with fucans such as hormones, genetic materials, peptides, antithrombotic agents, inhibitors of oxidative stress, agents to decrease plaque size, statins, HDL-cholesterol mimetic agents, fibrinolytic agents, anti-inflammatory agents, and antiproliferative agents. The present invention also provides a method of treating vulnerable atherosclerotic plaque and for inhibiting thrombosis, adhesion molecules and inflammation, and for enhancing endothelial regeneration comprising the step of administering locally and intramurally a pharmaceutical composition containing fucans and / or its functional equivalents having a molecular weight of 8Kda to less than 30 kDa either alone or in combination with a drug capable of synergistically acting with said fucans such as hormones, genetic material, peptides, antithrombotic agents, oxidative stress inhibiting agents, agents to decrease plaque size, statins, HDL- cholesterol mimetic agents, fibrinolytic agents, anti-inflammatory agents, and antiproliferative agents.

The present invention further relates to a method of administering a pharmaceutically effective dosage of a composition containing fucans and / or its functional equivalents directly and locally to the desired site either alone or in combination with one or more drug capable of synergistically acting with said fucans such as hormones, genetic material, peptides, antithrombotic agents, oxidative stress inhibiting agents, agents to decrease plaque size, statins, HDL-cholesterol mimetic agents, fibrinolytic agents, anti-inflammatory agents, and antiproliferative agents.

In another embodiment of the invention, the local administration of fucan may be performed in combination with the local delivery of another drug, hormone, chemical, pharmaceutical agent, genetic material, or peptide, that may have one or more functions as an anti-thrombotic, or, anti-inflammatory, or, that facilitates endothelial regeneration. The second agent to be administered combined with fucans is such that its effect will be complimentary to, or additive or synergistic with the effect of fucans in the treatment of vulnerable plaque. Such combinations may include but are not limited to combination of fucan with either anti-thrombotic agents, fibrinolytic agents, anti-proliferative agents, immunosuppressive agents, antiinflammatory agents such as but not limited to dexamethasone, or agents that enhance endothelial proliferation and function, hormones such as 17beta-estradiol, agents to decrease plaque size, statins, HDL-cholesterol mimetic agents, inhibitors of extracellular matrix synthesis, inhibitors of oxidative stress, etc.

Local delivery of fucans for the treatment of vulnerable plaque can be also administered to patients who are already on oral or parenteral medications for the treatment of established atherosclerosis and/or its complications. Such medications are easily obvious to those skilled in the art.

In another embodiment of the invention, fucans may be administered locally in the form of, for example but not limited to, any implantable intravascular device such as a drug-eluting stent for the prevention of restenosis following arterial injury, in view of its documented effects on inhibition of smooth muscle cell proliferation and inhibition of intimal hyperplasia after arterial injury (Religa P, et al. Fucoidan inhibits smooth muscle cell proliferation and reduces mitogen-activated protein kinase activity. Eur J Endovasc Surg 2000;20:419-26; Deux JF, et al. Low molecular weight fucoidan prevents neointimal hyperplasia in rabbit iliac artery in-stent restenosis model. Arterioscler Thromb Vase Biol 2002;22: 1604-9), effects of inhibition of adhesion molecules and inflammation (Berteau O, et al. Sulfated fucans, fresh perspectives: structures, functions, and biological properties of sulfated fucans and an overview of enzymes active towards this class of polysaccharides. Glycobiology 2003;13:29R-40R), and its favorable effects on endothelial regeneration (Giraux JL, et al. Modulation of human endothelial cell proliferation and migration by fucoidan and heparin. Eur J Cell Biol 1998;77:352-9; Matou S, et al. Effect of fucoidan on fibroblast growth factor-2 induced angiogenesis in vitro. Thromb Res 2002;106:213- 21; Matsubara K, et al. Effects of middle molecular weight fucoidans on in vitro and ex vivo angiogenesis of endothelial cells. Int J MoI Med 2005;15:695-9). Deux et al. (Deux JF, et al. Low molecular weight fucoidan prevents neointimal hyperplasia in rabbit iliac artery in-stent restenosis model. Arterioscler Thromb Vase Biol 2002;22: 1604-9) describe the prevention of restenosis by fucans delivered systemically. U. S. Patent No. 6828307 to Colliec- Jouault et al. describes the application of fucan locally by balloon catheters (which are non-implantable devices) for restenosis prevention. The local administration of fucans as an active agent by means of an intravascular implantable device such as a stent for the prevention of restenosis has not been described in the art. Furthermore, in addition to inhibition of smooth muscle cell proliferation and inhibition of inflammation, enhancing endothelial regeneration is also important in the prevention of restenosis {Lafont A, et al. Endothelial dysfunction and collagen accumulation: two independent factors for restenosis and constrictive remodelling after experimental angioplasty. Circulation. 1999;100:l 109-1115; Krasinski K, et al. Estradiol accelerates functional endothelial recovery after arterial injury. Circulation 1997;95:1768-72; Chandrasekar B, et al. Coronary artery endothelial protection following local delivery of 17-β estradiol during balloon angioplasty in a porcine model: a potential new pharmacological approach to improve endothelial function. J Am Coll Cardiol 2001 ;38: 1570-6). The local delivery of fucans to enhance endothelial regeneration and to inhibit inflammation as a method to prevent restenosis is novel, and non-obvious over the art of record. The drug-eluting stent may be metallic, made of metal alloy, non-metallic, or bio-degradable. The fucan may be released from the drug-eluting stent either with or without the use of polymers or other bio-degradable materials as drug carriers. Alternatively, the fucan may be released directly from a bare drug-eluting stent.

In another embodiment, the local administration of fucan for the prevention of restenosis may be performed in combination with the local delivery of another drug, hormone, chemical, pharmaceutical agent, genetic material, or peptide that is effective in the prevention of restenosis. Such combinations may include but are not limited to combination of fucan with either anti-proliferative agents, or immunosuppressive agents, or agents that enhance endothelial proliferation and function, hormones such as 17beta-estradiol, inhibitors of extracellular matrix synthesis, inhibitors of oxidative stress (the redox process) after arterial injury, etc.

In another embodiment of the invention, fucans may be administered locally either alone or in combination as described above for the treatment of vulnerable plaques in peripheral arteries such as the arteries supplying the limbs, renal arteries or carotid arteries. In yet another embodiment, fucans may be administered locally either alone or in combination with another agent as discussed above for the prevention of restenosis in peripheral arteries such as the arteries supplying the limbs, renal arteries or carotid arteries following arterial injury.

Natural, semi-synthesized, or synthesized substances, or, their derivatives that contain L-fucose branches (sulfated or non-sulfated), with or without varying concentrations of other monosaccharides such as but not limited to galactose, mannose, xylose, or uronic acid are considered as functional equivalents of fucans and are included within the scope of this invention. Drugs, chemicals, pharmaceutical agents, genetic material, peptides that are considered functional equivalents of fucans are also intended to be included within the scope of this invention. The description of functional equivalence to fucans will be easily obvious to those skilled in the art.

Although the invention has been described in detail with particular reference to these preferred embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents.

Claims

CLAIMS :

1. A pharmaceutical composition for treatment of vulnerable atherosclerotic plaque and for the inhibition of thrombosis, adhesion molecules and inflammation, and for enhancing endothelial regeneration comprises fucans and / or its functional equivalents having a molecular weight in the range of 8 kDa to less than 30 kDa either alone or in combination with at least a drug capable of synergistically acting with said fucans such as hormones, genetic materials, peptides, antithrombotic agents, inhibitors of oxidative stress, agents to decrease plaque size, statins, HDL-cholesterol mimetic agents, fibrinolytic agents, anti-inflammatory agents, and antiproliferative agents.

2. A method of treating vulnerable atherosclerotic plaque and for inhibiting thrombosis, adhesion molecules and inflammation, and for enhancing endothelial regeneration comprising the step of administering locally and intramurally a pharmaceutical composition containing fucans and / or its functional equivalents having a molecular weight of 8kDa to less than 30 kDa either alone or in combination with at least a drug capable of synergistically acting with said fucans such as hormones, genetic material, peptides, antithrombotic agents, oxidative stress inhibiting agents, agents to decrease plaque size, statins, HDL-cholesterol mimetic agents, fibrinolytic agents, antiinflammatory agents, and antiproliferative agents.

3. The method according to claim 2 wherein said pharmaceutical composition is an aqueous solution of fucans and / or its functional equivalents, or in the form of a suspension, or viscous gel, or hydrogel coated balloon, or an implantable device such as a drug-eluting stent.

4. A method of administering a pharmaceutically effective dosage of a composition containing fucans and / or its functional equivalents directly and locally to the desired site either alone or in combination with one or more drug capable of synergistically acting with said fucans such as hormones, genetic material, antithrombotic agents, oxidative stress inhibiting agents, agents to decrease plaque size, statins, HDL-cholesterol mimetic agents, fibrinolytic agents, anti-inflammatory agents, and antiproliferative agents.

5. The method according to claim 4, wherein said dosage is administered directly by means of a drag eluting stent positioned in the coronary or the peripheral arteries for treatment of vulnerable atherosclerotic plaque and / or for preventing restenosis.

6. Use of fucans and / or its functional equivalents for treatment of vulnerable atherosclerotic plaque and inhibition of thrombosis, adhesion molecules and inflammation, for enhancing endothelial regeneration, and for restenosis after arterial injury.