The present invention relates generally to the field of medicine, and relates specifically to methods and compositions for the treatment of diseases of the eye using antagonists of the integin receptors αvβ3 and/or αvβ5. More specifically, the invention relates to methods and compositions for the treatment of diseases of the eye using antagonists of the integrin receptors αvβ3 and/or αvβ5 wherein the compositions are administered by injection into the sclera of the eye.
Integrins are a class of cellular receptors known to bind extracellular matrix proteins, and therefore mediate cell-cell and cell-extracellular matrix interactions, referred generally to as adhäsion events. Integrins receptors constitute a family of proteins across membranes with shared structural characteristics heterodimeric glycoprotein complexes formed of α and β subunits.
One class of integrin receptors, the vitronectin receptor, named for its original characteristic of preferential binding to vitronectin, is known to refer to three different integrins, designated. αvβ3 and/or αvβ5. Horton, Int. J. Exp. Pathol., 71:741-759 (1990). αvβ1 binds fibronectin and vitronectin. αvβ3 binds a large variety of ligands, including fibrin, fibrinogen, laminin, thrombospondin, vitronectin, von Willebrand's factor, osteospontin and bone sialoprotein I. αvβ5 binds vitronectin. The specific cell adhesion roles these three integrins play in the many cellular interactions in tissues is still under investigation, but it is clear that there are different integrins with different biological functions.
One important recognition site in the ligand for many integrins is the arginine-glycine-aspartic acid (RGD) tripeptide sequence. RGD is found in all of the ligands identified above for the vitronectin receptor integrins. This RGD recognition site can be mimicked by polypeptides (“peptides”) that contain the RGD sequence, and such RGD peptides are known inhibitors of integrin function.
Integrin inhibitors containing the RGD sequence are disclosed, for example, in EP 0 770 622 A2. The compounds described inhibit in particular the interactions of β3 and/or β5-integrin receptors with ligands and are particularly active in the case of the integrins αvβ3, αvβ5 and aIIβ3, but also relative to αvβ3, αvβ6 and αvβ8 receptors. These actions can be demonstrated, for example, according to the method described by J. W. Smith et al. in J. Biol. Chem. 265, 12267-12271 (1990). In addition, the compounds possess anti-inflammatory effects.
On basis of integrin inhibitors containing the RGD sequence a multitude of antagonists without the RGD sequence have been made available. Those integrin inhibitors without RGD sequence are disclosed, for example, in WO 96/00730 A1, WO 96/18602 A1, WO 97/37655 A1, WO 97/06791 A1, WO 97/45137 A1, WO 97/23451 A1, WO 97/23480 A1, WO 97/44333 A1, WO 98/00395 A1, WO 98/14192 A1, WO 98/30542 A1, WO 99/11626 A1, WO 99/15178 A1, WO 99/15508 A1, WO 99/26945 A1, WO 99/44994 A1, WO 99/45927 A1, WO 99/50249 A2, WO 00/03973 A1, WO 00/09143 A1, WO 00/09503 A1, WO 00/33838 A1.
DE 1970540 A1 disclose bicyclic aromatic amino acids acting as integrin inhibitors of the αv integrin receptors, particulary of the integrins αvβ3 and αvβ5. The compounds are very particularly active as adhesion receptor antagonists for the vitronectin receptor αvβ3. This effect can be demonstrated, for example, by the method described by J. W. Smith et al. in J. Biol. Chem. 265, 11008-11013 and 12267-12271 (1990).
WO 00/26212 A1 discloses chromenone and chromanone derivatives acting as integrin inhibitors of the αv integrin receptors, particulary of the integrins αvβ3 and αvβ5. The compounds are also very particularly active as adhesion receptor antagonists for the vitronectin receptor αvβ3.
Integrin inhibitors have been suggested as pharmaceutically active principle in human and veterinary medicine, in particular for the prophylaxis and treatment of various disorders. Specifically suggested have been their use for the treatment and prophylaxis of the circulation, thrombosis, cardiac infarction, arteriosclerosis, inflammations, apoplexy, angina pectoris, tumor disorders, osteolytic disorders, especially osteoporosis, angiogenesis and disorders resulting from angiogenesis, for example diabetic retinopathy of the eye, macular degeneration, myopia, ocular histoplasmosis, rheumatic arthritis, osteoarthritis, rubeotic glaucoma, and also ulcerative colitis, Crohn's disease, multiple sclerosis, psoriasis and restenosis following angioplasty.
Eye diseases resulting from angiogenesis are the leading cause of visual loss in America. While in case of the population of the age of over 65 visual loss is predominantly effected by age-related macular degeneration (AMD) in case of population of the age of less than 65 this is predominantly effected by diabetic retinopathy.
In Wall Street Journal from Mar. 6 th, 2000 an overview about occurence and current therapies of AMD is given. According to this AMD currently afflicts some 12 million Americans. AMD progressively destroys the macula which is responsible for central vision and color vision. In some cases, deterioration of central vision to fuzzy blur can be rapid occuring in weeks or months. Two forms of the disease exists called “atrophic” and “exudative”. Although exudative AMD effects only 10% of the total AMD population, it accounts for 90% of all AMD-related blindness.
Until recently, the only treatment for exudative AMD consisted of directing a powerful laser beam at the harmful blood vessels to heat and coagulate them. However, only about 15% of patients with exudative AMD have been eligible for this laser surgery. Other therapies are currently in experimental phase. In one approach, called photodynamic therapy, a low-power laser is combined with injection of light-absorbing dye. Another therapy is a more surgical approach and is called “limited retinal translocation”. In this therapy the leaky vessels are destroyed with a high-powered laser after separation and rotation of the retina from the outer wall of the eye.
U.S. Pat. No. 5,766,591 discribes the use of RGD-containing αvβ3 antagonists for the treatment of patients in which neovascularisation in the retinal tissue occurs. More specifically the use of said antagonists for the treatment of patients with diabetic retinopathy, macular degeneration and neovasular glaucoma is suggested. However, no examples with regard to this indications are presented. Concerning to the route of administration only general information are given. Specifically intravenous, intraperitoneal, intramuscular, intracavital and transdermal application is mentioned. In all cases αvβ3 antagonists are preferred exhibiting selectivity for αvβ3 over other integrins such as αvβ5.
WO 97/06791 A1 discribes that αvβ5 antagonists can be used for inhibiting angiogenesis too. Likewise as suggested for αvβ3 antagonists in U.S. Pat. No. 5,766,591 αvβ5 antagonists are suggested for the treatment of a patient with diabetic retinopathy, macular degeneration and neovasular glaucoma. With regard to the route of administration intravenous, intraocular, intrasynovial, intramuscular, transdermal and oral application is specifically mentioned.
WO 00/07565 A1 discribes a method for application of pharmaceutically active substances to the eye via intrascleral injection into the scleral layer. The whole disclosure of WO 00/07565 A1 is incorporated to the present application by reference. As active substances a multitude of active substances is mentioned in WO 00/07565 A1 including integrin blockers. However, the term integrin blocker is silent with regard to the receptor type and refer to all substances acting as inhibitor on anyone of the large class of heterodimeric receptors formed from α and β subunits. Moreover, no examples for integrin blockers are given.
It has been found that inhibitors of αvβ3 and/or αvβ5 integrin receptors have particularly useful pharmacological and physicochemical properties combined with good tolerability, as, in particular, they can be used for prophylaxis and treatment of diseases of the eye of a patient resulting from angiogenesis in the eye by injecting the inhibitor into the scleral layer of the eye.
Accordingly, the invention is directed to a method for prophylaxis and/or treatment of diseases of the eye of a patient resulting from angiogenesis in the eye comprising injecting into the scleral layer of the eye of said patient a composition comprising a therapeutically effective amount of an αvβ3 and/or αvβ5 inhibitor sufficient to inhibit angiogenesis of the eye whereby injecting occurs through the location of the exterior surface of the sclera that overlies retinal tissue.
A therapeutically effective amount is an amount of inhibitor sufficient to produce a measureable inhibition of angiogenesis in the tissue of the eye when injected into the scleral layer. In general, this is the case when the αvβ3 and/or αvβ5 inhibitor is used in an amount from about 0.5 μg to about 5 mg.
The method of invention is especially usable for prophylaxis and/or treatment of diabetic retinopathy, macular degeneration, myopia and histoplasmosis.
In a preferred embodiment of the invention polypeptides containing the amino acid sequence RGD are used as αvβ3 and/or αvβ5 inhibitors in the method for prophylaxis and/or treatment of eye diseases. As mentioned above, RGD is the peptide sequence Arg-Gly-Asp (arginine-glycine-aspartic acid) occuring in natural ligands of integrins like fibronectin or vitronectin. Solvable RGD containing linear or cyclic peptides are able to inhibit interactions of this integrins with their corresponding natural ligands.
The abbreviations for the amino acid residues used hereinafter are shown in the following table:
Particularly preferred as αvβ3 and/or αvβ5 inhibitors to be used in the method for prophylaxis and/or treatment of eye diseases are compounds of formula I
cyclo-(Arg-Gly-Asp-D-(A)nE) I,
in which
In formula I alkyl is preferably methyl, ethyl, isopropyl, n-butyl, sec-butyl or tert-butyl.
More particular preferred polypeptides are used as αvβ3, αvβ5 inhibitors in the method of the invention that can be expressed by the subformula Ia, which otherwise corresponds to the formula I but in which
Furthermore, particular preference is given to the use of all physiologically compatible salts of the compounds which come under the subformula Ia.
Most preferred as active compound in said method are cyclo-(Arg-Gly-Asp-DPhe-Val) and cyclo-(Arg-Gly-Asp-DPhe-NMeVal).
This RGD-containing peptides described by formula I as well as the peptides specifically mentioned hereinbefore are disclosed in EP 0 770 622 A2, the disclosure of which is hereby incorporated to the present application by reference. Accordingly, the meaning of the substituents of formula I resp. subformula Ia are the same as defined for the substituents of subformula Ia resp. subformula Ib as disclosed on page 5, line 24 to line 32 resp. page 5, line 33 to line 41 in EP 0 770 662 A2.
It has been found that inhibitors of αvβ3, αvβ5 integrin receptors which are no polypeptides and do not contain the RGD sequence can also be used for prophylaxis and treatment of diseases of the eye of a patient resulting from angiogenesis in the eye by injecting the inhibitor into the scleral layer of the eye.
Therefore, in one further preferred embodiment of the method of invention the αvβ3 and/or αvβ5 inhibitors to be used in the method for prophylaxis or treatment of eye diseases are compounds of formula II
wherein
Particularly preferred αvβ3, αvβ5 inhibitors are used in the method of invention that can be expressed by the subformulae IIa to IIg, which otherwise corresponds to the formula II but in which
in IIa)
The compounds of formula II and subformulae IIa to IIg have been disclosed in DE 197 05 450 A1, the whole disclosure of which is hereby incorporated to the present application by reference. Accordingly, the substituents of formula II resp. subformulae IIa to IIg have the same meaning as defined for the substituents of formula I resp. subformulae Ia to Ig as disclosed on page 2, lines 3 to 43 resp. page 5, line 58 to page 7, line 30 of DE 197 05 450 A1. The definitions for the substituents are given on page 4, line 35 to page 5, line 56 of DE 197 05 450 A1.
More particularly preferred one of the following αvβ3 and/or αvβ5 inhibitors is used in the method of the present invention:
Most preferred are
In one further preferred embodiment of the method of invention the αvβ3 and/or αvβ5 inhibitors to be used in the method for prophylaxis or treatment of eye diseases are compounds of formula II
in which
In this embodiment of the method of the present invention particularly preferred αvβ3 and/or αvβ5 inhibitors are used that can be expressed by the subformulae IIIa to in IIIn, which otherwise correspond to formula III but in which
in IIIa)
The compounds of formula III and subformulae IIIa to in IIIn have been disclosed in WO 00/26212 A1, the whole disclosure of which is incorporated to the present application by reference. Accordingly, the substituents of formula III resp. subformulae IIIa to in IIIn have the same meaning as defined for the substituents of formula I resp. subformulae Ia to In as disclosed on page 1, line 5 to page 2, line 31 resp. page 13, line 20 to page 15, line 6 of WO 00/26212 A1. The definitions for the substituents are given on page 8, line 18 to page 13, line 10 of WO 00/26212 A1.
More particularly preferred one of the following αvβ3 and/or αvβ5 inhibitors is used in this embodiment of the method of the present invention:
Most preferred are
In one further preferred embodiment of the method of invention the αvβ3 and/or αvβ5 inhibitors to be used in the method for prophylaxis or treatment of eye diseases are compounds of formula IV
wherein
In this embodiment of the method of invention particularly preferred αvβ3 and/or αvβ5 inhibitors are used that can be expressed by the subformulae IVa to IVi, which otherwise correspond to formula IV but in which
in IVa
in IVb
in IVc
in IVd
in IVe
in IVf
in IVg
in IVh
in IVi
More particularly preferred the αvβ3 and/or αvβ5 inhibitor according to formula IV to be used in the method of the present invention is:
Most preferred the αvβ3 and/or αvβ5 inhibitor according to formula IV to be used in the method of the present invention is
This compounds as well as the compounds of formula IV and subformulae IVa to IVi are disclosed in copending german patent application no. 100 06 139.7, the whole disclosure of which is hereby incorporated to the present application by reference. Accordingly, the substituents of formula IV and subformulae IVa to IVi have the same meaning as defined for the substituents of formula I resp. subformulae Ia to Ii as disclosed on page 1, line 3 to page 2, line 13 resp. page 17, line 4 to page 20, line 9 of german patent application no. 100 06 139.7. The definitions for the substituents are given on page 9, line 6 to page 16, line 28 of german patent application no. 100 06 139.7.
The particular suitability of the compounds as described hereinbefore for using in the method of treatment of eye diseases was experimentally confirmed for some representative compounds.
Inhibition of angiogenesis after intrascleral application of the compounds can be demonstrated by quantification of neovascularisation in the eye after stimulation of angiogenesis and subsequent intrascleral application of the αvβ3 and/or αvβ5 inhibitor. One model suitable for demonstrating the inhibiting effect of αvβ3 and/or αvβ5 inhibitor on angiogenesis is, for example, the rabbit corneal micropocket model described by Shaffer R. W. et al., in: Molecular, Cellular, and Clinical Aspects of Angiogenesis, Maragoudakis E. (ed.), Plenum Press, New York, 241ff. (1996). In this model angiogenesis is stimulated by implantation of Hydron pellets containing an angiogenesis stimulating cytokine like, for example, fibroblast growth factor (FGF) or vascular endothelial growth factor (VEGF) into the cornea. After implantation the active compound to be tested is administered by paralimbal intrascleral injection. Effect on neovascularisation is measured after predetermined time intervals by visual examination using a microscope, photographing and computer-assisted quantification of photographs.
As an alternative to application of cytokine induced angiogenesis, induction of angiogenesis can also be performed by laser photocoagulation, as, for example, described by Murata T. et al., IOVS, 41, 2309ff. (2000).
It is a further object of the invention to provide a composition suitable for the method for prophylaxis and treatment of diseases of the eye of a patient resulting from angiogenesis comprising injecting into the scleral layer of the eye of said patient a composition comprising a therapeutically effective amount of an αvβ3 and/or αvβ5 inhibitor sufficient to inhibit angiogenesis of the eye.
The formulation used for administration of the compound into the scleral layer of the eye can be any form suitable for application into the sclera by injection through a cannula with small diameter suitable for injection into the scleral layer. Examples for injectable application forms are solutions, suspensions or colloidal suspensions. The sclera is a thin avascular layer, comprised of highly ordered collagen network surrounding most of vertebrate eye. Since the sclera is avascular it can be utilized as a natural storage depot from which injected material cannot rapidly removed or cleared from the eye.
Depending from the application form the active compound liberates in an immediate or a sustained release manner. A sustained release formulation is preferred because the injection frequency can be further reduced.
One possibility to achieve sustained release kinetics is embedding or encapsulating the active compound into nanoparticles. Nanoparticles can be administrated as powder, as powder mixture with added excipients or as suspensions. Colloidal suspensions of nanoparticles are preferred because they can easily be administrated through a cannula with small diameter.
Nanoparticles are particles with a diameter from about 5 nm to up to about 1000 nm. The term “nanoparticles” as it is used hereinafter refers to particles formed by a polymeric matrix in which the active compound is dispersed, also known as “nanospheres”, and also refers to nanoparticles which are composed of a core containing the active compound which is surrounded by a polymeric membrane, also known as “nanocapsules”. For administration into the sclera of the eye nanoparticles are preferred having a diameter from about 50 nm to about 500 nm, in particular from about 100 nm to about 200 nm.
Nanoparticles can be prepared by in situ polymerization of dispersed monomers or by using preformed polymers. Since polymers prepared in situ are often not biodegradable and/or contain toxicological serious byproducts nanoparticles from preformed polymers are preferred. Nanoparticles from preformed polymers can be prepared by different techniques, i.e. by emulsion evaporation, solvent displacement, salting-out and by emulsification diffusion.
Emulsion evaporation is the classical technique for preparation of nanoparticles from preformed polymers. According to this technique, the polymer and the active compounds are dissolved in a water-immiscible organic solvent, which is emulsified in an aqueous solution. The crude emulsion is then exposed to a high-energy source such as ultrasonic devices or passed through high pressure homogenizers or microfluidizers to reduce the particle size. Subsequently the organic solvent is removed by heat and/or vacuum resulting in formation of the nanoparticles with a diameter of about 100 nm to about 300 nm. Usually, methylene chloride and chloroform are used as organic solvent because of their water insolubility, good solubilizing properties, easy emulsification and high volatility. These solvents are, however, critical in view of their physiological tolerability. Moreover, the high shear force needed for particle size reduction can lead to damage of polymer and/or the active compound.
The solvent displacement process was firstly described in EP 0 274 961 A1. In this process the active compound and the polymer are dissolved in an organic solvent which is miscible with water in all proportions. This solution is introduced in an aqueous solution containing a stabilizer under gentle agitation resulting in spontaneous formation of nanoparticles. Examples for suitable organic solvents and stabilizer are acetone or ethanol resp. polyvinyl alcohol. Advantageously chlorinated solvents and shear stress can be avoided. The mechanism of formation of nanoparticles has been explained by interfacial turbulence generated during solvent displacement (Fessi H. et al., Int. J. Pharm. 55 (1989) R1-R4). Recently, a solvent displacement technique was disclosed by WO 97/03657 A1, in which the organic solvent containing the active compound and the polymer is introduced into the aqueous solution without agitation.
The salting-out technique was firstly described in WO 88/08011 A1. In this technique a solution of a water-insoluble polymer and an active compound in a water-soluble organic solvent, especially acetone, is mixed with a concentrated aqueous viscous solution or gel containing a colloidal stabilizer and a salting-out agent. To the resulting oil-in-water emulsion water is added in a quantity sufficient to diffuse into the aqueous phase and to induce rapid diffusion of the organic solvent into the aqueous phase leading to interfaciale turbulence and formation of nanoparticles. The organic solvent and the salting-out: agent remaining in the suspension of nanoparticles are subsequently eliminated by repeated washing with water. Alternatively, the solvent and salting-out agent can be eliminated by cross-flow filtration.
In emulsification-diffusion process the polymer is dissolved in a water-saturated partially water-soluble organic solvent. This solution is mixed with an aqueous solution containing a stabilizer resulting in an oil-in-water emulsion. To this emulsion water is added causing the solvent to diffuse into the aqueous external phase accompanied with formation of nanoparticles. During particle formation each emulsion droplet leads to several nanoparticle. As this phenomenon cannot be fully explained by convection effect caused by interfacial turbulence, it has been proposed that diffusion of organic solvent from the droplets of the crude emulsion carries molecules of active compound and polymer phase into the aqueous phase resulting in supersaturated local regions, from which the polymer aggregates in the form of nanoparticles (Quintanar-Guerrero D. et al. Colloid. Polym. Sci. 275 (1997) 640-647). Advantageously, pharmaceutically acceptable solvents like propylene carbonate or ethyl acetate can be used as organic solvents.
With the methods described above nanoparticles can be formed with various types of polymers. For use in the method of the present invention, which involves injection of the formulation into the sclera of the eye, nanoparticles made from biocompatible polymers are preferred. The term “biocompatible” refers to material which, after introducing in a biological environment, have no serious effects to the biological environment. From biocompatible polymers those polymers are especially preferred which are also biodegradable. The term “biodegradable” refers to material which, after introducing in a biological environment, is enzymatically or chemically degraded into smaller molecules which can be eliminated subsequently.
Biodegradable polymers are well known by the person skilled in the art. Examples are polyesters from hydroxycarboxylic acids such as poly(lactic acid) (PLA), poly(glycolic acid) (PGA), polycaprolactone (PCL), copolymers of lactic acid and glycolic acid (PLGA), copolymers of lactic acid and caprolactone, polyepsilon caprolactone, polyhyroxy butyric acid and poly(ortho)esters, polyurethanes, polyanhydrides, polyacetals, polydihydropyrans, polycyanoacrylates, natural polymers such as alginate and other polysaccharides including dextran and cellulose, collagen and albumin.
Liposomes are a further drug delivery system which is easily injectable. Accordingly, in the method of invention the active compounds can also be administered into the sclera of the eye in the form of a liposome delivery system. Liposomes are well-known by a person skilled in the art. Liposomes can be formed from a variety of phospholipids, such as cholesterol, stearylamine of phosphatidylcholines. Liposomes being usable for the method of invention encompass all types of liposomes including, but not limited to, small unilamellar vesicles, large unilamellar vesicles and multilamellar vesicles.
The effect of intrascleral application of an αvβ3 and/or αvβ5 inhibitor was examined in rabbit corneal micropocket model as described by Shaffer R. W. (see above). As an example for an αvβ3 and/or αvβ5 inhibitor (2S)-2-(2,2-dimethylpropyloxycarboxamido)-3-{3,4-dihydro-2-[N-(2-imidazolyl)carbamoylethyl]-(2S)-2H-1,4-benzoxazin-3-on-6-yl}propionic acid was used in the experiment. For induction of angiogenesis Hydron pellets containing basic fibroblast growth factor (bFGF) were used. Preparation of bFGF containing implants was performed by casting Hydron [poly(hydroxyethyl)methacrylate] in specially prepared Teflon pegs that have a 5 mm core drilled into their surfaces. Approximately 12 μl of casting material was placed into each peg and polymerized overnight in a sterile hood, then sterilized by ultraviolet irradiation.
The experiment consisted of 12 animals; in each eye of the animals one individual pellet was implanted into a surgically created “pocket” in the mid stroma of the rabbit cornea. The surgical procedure was done under sterile technique using a Wild model M691 operating microscope equipped with a beamsplitter and camera for photographically recording individual corneas. A 69 Beaver blade was used to create a 3 mm by 5 mm “pocket” to a depth of half the corneal thickness. The stroma was dissected peripherally using an spatula and the pellet implanted with its peripheral margin 2 mm from limbus. Immediately after implantation of bFGF-containing Hydron pellets 6 of the 12 animals received in each eye 100 μl of a drug solution consisting of 2.0 mg/ml (2S)-2-(2,2-dimethylpropyloxycarboxamido)-3-3,4-dihydro-2-[N-(2-imidazolyl)carbamoylethyl]-(2S)-2H-1,4-benzoxazin-3-on-6-yl}propionic acid solubilized in phosphate buffered saline (PBS) by paralimbal intrascleral injection. For comparison the same procedure was performed in the other 6 animals using PBS only. Following implantation the eyes were photographed and the area of neovascularisation measured after predetermined intervals. The results obtained 5 and 7 days post implantion are presented in tables 1 and 2.
5 days post implantation neovascularisation was inhibited by 56.5% (p<0.01) in the group of animals receiving drug solution compared to the animal group receiving PBS only.
7 days post implantation neovascularisation was inhibited by 52.3% (p<0.01) in the group of animals receiving drug solution compared to the animal group receiving PBS only.
The results obtained clearly demonstrate the advantagous effect of the present invention. Although only a single dosis of αvβ3 and/or αvβ5 inhibitor was given and drug formulation was only a solution, strong inhibition of neoascularization was performed over many days.
Number | Date | Country | Kind |
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00124817.8 | Nov 2000 | EP | regional |
Number | Date | Country | |
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60244606 | Nov 2000 | US |
Number | Date | Country | |
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Parent | 10415484 | Apr 2003 | US |
Child | 11448001 | Jun 2006 | US |