WO2014108410A1

WO2014108410A1 - Combination therapies for treating ocular disorders

Info

Publication number: WO2014108410A1
Application number: PCT/EP2014/050170
Authority: WO
Inventors: Mireia COMA; Patrick ALOY; Albert PUJOL; José Manuel MAS; Jordi NAVAL
Original assignee: Anaxomics Biotech, Sl
Priority date: 2013-01-08
Filing date: 2014-01-07
Publication date: 2014-07-17

Abstract

The invention is directed to combinations of Bethanidine and Levetiracetam, to pharmaceutical compositions, kits and treatment methods for the treatment or prevention of ocular disorders, particularly disorders associated with optic neuropathy and/or retinal ganglion cells degeneration, including glaucoma.

Description

COMBINATION THERAPIES FOR TREATING OCULAR DISORDERS

FIELD OF THE INVENTION The present invention relates generally to the field of ophthalmology. The invention features a novel combinations useful for the treatment of ocular disorders associated with optic neuropathy and/or retinal ganglion cells degeneration, including glaucoma. The invention also relates to methods of treatment of ocular disorders associated with optic neuropathy and/or retinal ganglion cells degeneration including the pharmaceutical combinations of the invention.

BACKGROUND OF THE INVENTION Blindness affects 60 million people worldwide. The leading causes of irreversible blindness include age-related macular degeneration, retinal vascular diseases and glaucoma. Loss of sight affects activities of daily living and substantially reduces quality of life. The leading causes of visual impairment are age-related, and cause damage to the retina and optic nerve (Zhang, K., Zhang, L. & Weinreb, R.N. Ophthalmic drug discovery: novel targets and mechanisms for retinal diseases and glaucoma. Nat Rev Drug Discov 1 1 , 541 -59)

Glaucoma is a complex disease that comprises a group of heterogeneous optic neuropathies characterized by a progressive degeneration of the optic nerve head and visual field defects. It affects more than 66 million people, with at least 6-8 million bilaterally blind (Weinreb, R.N. & Khaw, P.T. Primary open-angle glaucoma. Lancet 363, 171 1 -20 2004).

Glaucoma is characterized by a slow and progressive degeneration of retinal ganglion cells (RGCs) and their axons, resulting in a concomitant pattern of vision loss. Factors such as vascular insufficiency and intraocular pressure are associated with the initiation and progression of glaucomatous changes (Zhang, K., Zhang, L. & Weinreb, R.N. Ophthalmic drug discovery: novel targets and mechanisms for retinal diseases and glaucoma. Nat Rev Drug Discov 1 1 , 541 - 59). The early detection and treatment of glaucoma is critical as the evolution of the disease causes permanent blindness. Once the peripheral or central vision is lost due to glaucoma, any treatment can restore visual field loss. Currently available medications for the treatment of glaucoma belong to several pharmacological classes, including β-adrenergic blockers, cholinergic agonists, carbonic anhydrase inhibitors and alpha agonists. All operate lowering the intraocular pressure. Although many patients benefit from the widespread use of safe and effective medications to lower intraocular pressure, as much as 10% of people who receive proper treatment still experience vision loss (Kass, M.A. et al. The Ocular Hypertension Treatment Study: a randomized trial determines that topical ocular hypotensive medication delays or prevents the onset of primary open-angle glaucoma. Arch Ophthalmol 120, 701 -13; discussion 829- 30 (2002) and Heijl, A., Leske, M.C., Bengtsson, B., Hyman, L. & Hussein, M. Reduction of intraocular pressure and glaucoma progression: results from the Early Manifest Glaucoma Trial. Arch Ophthalmol W0, 1268-79 (2002).

Interventions which focus only on the intraocular pressure reduction may not be beneficial for 10% of the patients with glaucoma. Reducing or slowing down the loss of ganglion cells in glaucoma with neuroprotectants treatments, would appear to be the only way forward. To date, only a few clinical trials have been carried out to investigate the efficacy of neuroprotective agents in retinal neurodegeneration as per example memantine (Namenda; Forest/I und beck) for glaucoma with unsuccessful results (Osborne, N.N. Recent clinical findings with memantine should not mean that the idea of neuroprotection in glaucoma is abandoned. Acta Ophthalmol 87, 450-4 (2009)) or brimonidine (Aiphagan; Allergan) for age-related macular degeneration (Zhang, K., Zhang, L. & Weinreb, R.N. Ophthalmic drug discovery: novel targets and mechanisms for retinal diseases and glaucoma. Nat Rev Drug Discov 1 1 , 541 -59.).

The pathophysiology of glaucomatous neurodegeneration is still not fully understood. Elevated intraocular pressure, local ischaemia-hypoxia, excessive stimulation of the glutamatergic system, alterations in glial cells or astrocytes, and aberrant immunity contributes to glaucomatous neurodegeneration (Weinreb, R.N. & Khaw, P.T. Primary open-angle glaucoma. Lancet 363, 171 1 - 20 (2004)). The multiple molecular mechanisms underlying glaucoma pathogenesis indicate that a multi-target polypharmacological research is needed to interact with different targets and modify different molecular pathways. The discovery of drug combinations and the understanding of their complex modes of action will outline an avenue of therapies against degenerative diseases. Clinical success with multicomponent therapies and multi-targeted agents has been shown in other pathologies such as asthma, hyperlipidemia, HIV-1 or cancer.

Retinal ganglion cells degeneration has been reported to play a role in a number of ocular disorders such as glaucoma, angle-closure glaucoma, neovascular glaucoma, open-angle glaucoma, low tension glaucoma, glaucoma associated with ocular disorder, glaucomatous visual field constriction (see EP 2 251 009), glaucomatous optic atrophy (see EP 2 251 009), papilledema (see EP 0 866 719), papillitis (see EP 0 866 719), ischemia (see EP 0 866 719) pressure-independent glaucomatous optic neuropathy (see Levin, LA and al., Arch Ophthalmol. (1996) ;1 14(4):488-91 ), ischemic optic neuropathy (see Levin, LA and al., Arch Ophthalmol. (1996) ;1 14(4):488-91 ), inflammatory optic neuropathy (see US 6,291 ,506), compressive optic neuropathy , traumatic optic neuropathy (see US 6,291 ,506), retinitis pigmentosa (see Garcia-Ayuso D et al, Exp Eye Res. (2010); 91 (6):800-10 and US 8,278,284 B2), retinal detachment (see US 8,278,284), retinal ischemic disease (see US 8,278,284), age related macular degeneration (see Kern TS et al., J Physiol. (2008) 15;586(Pt 18):4401 -8), diabetic retinopathy (see Kern TS et al., J Physiol. (2008) 15;586(Pt 18):4401 -8), uveoretinitis, vitreoretinopathy (see Zhong YS et al., Mol Med Rep. (2013) 8(2):31 1 -9), acute optic neuritis (see Shindler KS et al., Mult Scler. (2006) 12(5):526-32), dominant optic atrophy (see Lenaers G et al., Orphanet J Rare Dis. (2012) 9;7:46), Leber's hereditary optic neuropathy (see Newman NJ et al., Brain. (201 1 ) 134(Pt 9):2447-50), optic nerve injuries (see Tang Z et al., J Vis Exp. (201 1 ) 25;(50), ocular hypertension (see Mi XS et al, PLoS One. (2012); 7(10):e45469), central retinal artery occlusion, ischemic central retinal vein thrombosis (see Kaur C et al., Clin Ophthalmol. (2008) ; 2(4):879-89), retinopathy of prematurity (ROP) (see Sivakumar V et al, J Pathol. (201 1 ) 224(2):245-60), retinal ganglion degeneration, and optic neuropathy due to a toxic agent or neuropathy caused by adverse drug reactions or vitamin deficiency (see You Y et al., Rev Neurosci. (2013); 24(3):301 -21 ). SUMMARY OF THE INVENTION

Now, the inventors have surprisingly found that a novel combination of Bethanidine and Levetiracetam is capable of providing neuroprotection to retinal ganglion cells, more particularly a synergistic degree of neuroprotection. Thus, the present invention is directed to a combination of Bethanidine and Levetiracetam, to pharmaceutical compositions, kits and treatment methods for the treatment or prevention of ocular disorders, particularly disorders associated with optic neuropathy and/or retinal ganglion cells degeneration.

In a first aspect the present invention is directed to a combination comprising bethanidine or its pharmaceutically acceptable salts and levetiracetam or its pharmaceutically acceptable salts. In a second aspect the present invention is directed to a composition comprising a combination of bethanidine or its pharmaceutically acceptable salts and levetiracetam or its pharmaceutically acceptable salts.

In a third aspect the present invention is directed to a combination of bethanidine or its pharmaceutically acceptable salts and levetiracetam or its pharmaceutically acceptable salts or to a composition comprising said combination for use in the treatment of ocular disorders associated with optic neuropathy and/or retinal ganglion cell degeneration. The compositions and/or combinations of the present invention are particularly suitable for treating ocular disorders associated with retinal ganglion cells degeneration such as glaucoma, angle-closure glaucoma, neovascular glaucoma, open-angle glaucoma, low tension glaucoma, glaucoma associated with ocular disorder, glaucomatous visual field constriction, glaucomatous optic atrophy, papilledema, papillitis, ischemia, pressure-independent glaucomatous optic neuropathy, ischemic optic neuropathy, inflammatory optic neuropathy, compressive optic neuropathy, traumatic optic neuropathy, retinitis pigmentosa, retinal detachment, and retinal ischemic disease, age-related macular degeneration, diabetic retinopathy, uveoretinitis, vitreoretinopathy, acute optic neuritis, dominant optic atrophy, Leber's hereditary optic neuropathy, optic nerve injuries, ocular hypertension, central retinal artery occlusion, ischemic central retinal vein thrombosis, retinopathy of prematurity (ROP), retinal ganglion degeneration, optic neuropathy due to a toxic agent or neuropathy caused by adverse drug reactions or vitamin deficiency.

In a fourth aspect the present invention is directed to the use of a combination of bethanidine or its pharmaceutically acceptable salts and levetiracetam or its pharmaceutically acceptable salts or to a composition comprising said combination for the manufacture of a medicament for the treatment of ocular disorders associated with optic neuropathy and/or retinal ganglion cell degeneration.

In a fifth aspect the present invention is directed to a method of treating a subject suffering a disorder associated with optic neuropathy and/or retinal degeneration comprising the administration to said subject of a therapeutically effective amount of a combination of bethanidine or its pharmaceutically acceptable salts and levetiracetam or its pharmaceutically acceptable salts or a composition comprising said combination.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGURE 1 . Neuroprotective effect of bethanidine plus levetiracetam in experimental model of glaucoma. Representative image of RGCs distribution in bethanidine plus levetiracetam and vehicle treated retinas. Isodensity maps of the same retina showing the distribution of RGCs FG+ (left) and RGCs Brna3+ (right). FIGURE 2. Neuroprotective effect of bethanidine plus levetiracetam in experimental model of glaucoma. Ratio of survival of RGCs identified by Brna3+ expression (Brna3+) respect to FG tracing (FG+) after bethanidine plus levetiracetam or vehicle treatment (p<0.01 ;^**, p<0.001 ; ^***, Mann-Whitney U test).

Ocular disorders associated with optic neuropathy and/or retinal degeneration The composition and/or combinations of the invention are particularly suitable for treating ocular disorders associated with retinal ganglion cells degeneration such as glaucoma, angle-closure glaucoma, neovascular glaucoma, open-angle glaucoma, low tension glaucoma, glaucoma associated with ocular disorder, glaucomatous visual field constriction, glaucomatous optic atrophy, papilledema, papillitis, ischemia, pressure-independent glaucomatous optic neuropathy, ischemic optic neuropathy, inflammatory optic neuropathy, compressive optic neuropathy, traumatic optic neuropathy, retinitis pigmentosa, retinal detachment, and retinal ischemic disease, age-related macular degeneration, diabetic retinopathy, uveoretinitis, vitreoretinopathy, acute optic neuritis, dominant optic atrophy, Leber's hereditary optic neuropathy, optic nerve injuries, ocular hypertension, central retinal artery occlusion, ischemic central retinal vein thrombosis, retinopathy of prematurity (ROP), retinal ganglion degeneration, optic neuropathy due to a toxic agent or neuropathy caused by adverse drug reactions or vitamin deficiency.

In a particular embodiment the compounds are used to prepare a medicine for treating a mammal in need thereof, in particular a human patient, wherein compounds are used in a dosage from 0.0037 mg to 37000 mg per m² of body weight, in particular from 0.37mg to 3700 mg per m² of body weight.

In particular, the combination of bethanidine + levetiracetam is ocular administrated daily in a range from 0.01 % to 10% solution for both bethanidine and levetiracetam.

In particular, the combination of bethanidine + levetiracetam is used in a range from 0.005 mg/m²/day to 1 1 10 mg/m²/day, preferably 0.005 mg/m²/day to 370 mg/m²/day, more preferably from 0.010 mg/m²/day to 185 mg/m²/day of bethanidine and 0.037 mg/m²/day to 1850 mg/m²/day, preferably from 1 1 1 to 1850 mg/m²/day of levetiracetam.

Doses of active ingredients may be expressed either in mg of active ingredient per kg of body weight or in mg of active ingredient per square meter of body surface. The article from Reagan-Shaw S. "Dose translation from animal to human studies revisited". FASEB J 2007, 22:659-661 provides the standard conversion factors used to convert mg/kg to mg/m². Dose (mg/kg) x K_m = Dose (mg/m²)

The article also explains that this conversion is the basis for converting dose in a first animal species to dose in a second animal species (allometric dose translation). Thus, animal dose (AD) in mg/kg can be converted to human equivalent dose (HED) in mg/kg using the following formula:

Animal K_m

HED (mg/kg) = AD (mg/kg) X

Human K_m wherein the K_m for each species is shown in Table I (data extracted from Reagan-Shaw S. Dose translation from animal to human studies revisited. FASEB J 2007, 22:659-661 ).

Table I. K_m factor for conversion of AD to HED

In the context of the present invention bethanidine is used to designate the compound 3-benzyl-2,1 -dimethylguanidine or its pharmaceutically acceptable salts. Whenever the present specification contains references to quantities of bethanidine salts they are meant to refer to the quantities expressed as bethanidine in free form.

In the context of the present invention levetiracetam is used to designate the compound (S)-2-(2-oxopyrrolidin-1 -yl)butanamide or its pharmaceutically acceptable salts. Whenever the present specification contains references to quantities of levetiracetam salts they are meant to refer to the quantities expressed as levetiracetam in free form. Pharmaceutical Compositions

This invention also provides pharmaceutical compositions that comprise compounds of this invention formulated together with one or more non-toxic pharmaceutically acceptable carriers. The pharmaceutical compositions may be specially formulated for any mode of administration that is medically acceptable, meaning any mode that produces effective levels of the active compounds without causing clinically unacceptable adverse effects.

In one preferred embodiment, compositions of the invention are administered intraocularly and/or orally. Other modes of administration include topical, buccal, transdermal, within/on implants, or parenteral routes. The term "parenteral" includes subcutaneous, intrathecal, intravenous, intraocular, intramuscular, intraperitoneal, intra-articular injection or infusion. Compositions of the invention can be added to a physiological fluid, such as to the intravitreal humor.

In a particular embodiment, the ophthalmic composition of the present invention may be used in either preparation form of an ophthalmic injection (an agent for subconjunctival injection, an agent for ocular injection and an agent for intraocular injection), an ophthalmic agent for external application (an agent for dropping in eyes and an agent for an ophthalmic ointment), an agent for internal application, an agent for intravenous injection, an agent for intramuscular injection and an agent for subcutaneous injection. In a particular embodiment, the compositions of the invention are administered through micro/nanospheres or controlled drug device suitable for direct implantation into the vitreous of the eye. Biocompatible polymers may be used in achieving controlled release of an active substance, include for example, polylactic acid, polyglycolic acid, copolymers of polylactic and polyglycolic acid, polyepsilon caprolactone, polyhydroxybutyric acid, polyorthoesters, polyacetals, polyhydropyrans, polycyanoacrylates, and cross-linked or amphipathic block copolymers of hydrogels.

The invention particularly provides pharmaceutical compositions that comprise Bethanidine and Levetiracetam, formulated together with one or more pharmaceutically acceptable carriers. The pharmaceutical compositions may be specially formulated for ophthalmic route of administration in solid or liquid form, oral administration in solid or liquid form, for parenteral injection, or for rectal administration.

The term "pharmaceutically acceptable carrier" as used herein means a non- toxic, inert solid, semi-solid or liquid filler, diluent, encapsulating material or formulation auxiliary of any type. Some examples of materials which can serve as pharmaceutically acceptable carriers are sugars such as lactose, glucose and sucrose; starches such as corn starch and potato starch; cellulose and its derivatives such as sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate; powdered tragacanth; malt; gelatin; talc; excipients such as cocoa butter and suppository waxes; oils such as peanut oil, cottonseed oil, safflower oil, sesame oil, olive oil, corn oil and soybean oil; glycols; such a propylene glycol; esters such as ethyl oleate and ethyl laurate; agar; buffering agents such as magnesium hydroxide and aluminum hydroxide; alginic acid; pyrogen-free water; isotonic saline; Ringer's solution; ethyl alcohol, and phosphate buffer solutions, as well as other non-toxic compatible lubricants such as sodium lauryl sulfate and magnesium stearate, as well as coloring agents, releasing agents, coating agents, sweetening, flavoring and perfuming agents, preservatives and antioxidants can also be present in the composition, according to the judgment of the formulator. This invention provides pharmaceutical compositions which comprise compounds of the invention formulated together with one or more non-toxic pharmaceutically acceptable carriers. The pharmaceutical compositions can be formulated for ophthalmic route of administration in solid or liquid form, oral administration in solid or liquid form, for topical administration in solid or liquid form, for parenteral injection or for rectal administration. The pharmaceutical compositions of this invention can be administered to humans (patients) and other mammals ocularly, orally, rectally, parenterally, intracisternally, intraperitoneally, topically (as by powders, ointments or drops, both over skin or over body external mucoses, including but not limited to topical ocular application to the eye and eye attached parts, organs or glandules), bucally or as an oral or nasal spray. The term "parenterally," as used herein, refers to modes of administration which include intraocular, subcutaneous, intrathecal, intravenous, intramuscular, intraperitoneal, intraarticular injection or infusion. Compositions comprising a composition of the invention can be added to a physiological fluid, such as to the intravitreal humor.

Pharmaceutical compositions of this invention for parenteral injection comprise pharmaceutically acceptable sterile aqueous or non-aqueous solutions, dispersions, suspensions or emulsions and sterile powders for reconstitution into sterile injectable solutions or dispersions. Examples of suitable aqueous and non-aqueous carriers, diluents, solvents or vehicles include water, ethanol, polyols (propylene glycol, polyethylene glycol, glycerol, and the like), suitable mixtures thereof, vegetable oils (such as olive oil) and injectable organic esters such as ethyl oleate. Proper fluidity may be maintained, for example, by the use of a coating such as lecithin, by the maintenance of the required particle size in the case of dispersions, and by the use of surfactants.

These compositions may also contain adjuvants such as preservative agents, wetting agents, emulsifying agents, and dispersing agents. Prevention of the action of microorganisms may be ensured by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, and the like. It may also be desirable to include isotonic agents, for example, sugars, sodium chloride and the like. Prolonged absorption of the injectable pharmaceutical form may be brought about by the use of agents delaying absorption, for example, aluminum monostearate and gelatin.

In some cases, in order to prolong the effect of a drug, it is often desirable to slow the absorption of the drug from subcutaneous or intramuscular injection. This may be accomplished by the use of a liquid suspension of crystalline or amorphous material with poor water solubility. The rate of absorption of the drug then depends upon its rate of dissolution which, in turn, may depend upon crystal size and crystalline form. Alternatively, delayed absorption of a parenterally administered drug form is accomplished by dissolving or suspending the drug in an oil vehicle. Suspensions, in addition to the active compounds, may contain suspending agents, as, for example, ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar, tragacanth, and mixtures thereof. If desired, and for more effective distribution, the compounds of this invention can be incorporated into slow-release or targeted-delivery systems such as polymer matrices, liposomes, and microspheres. They may be sterilized, for example, by filtration through a bacteria-retaining filter or by incorporation of sterilizing agents in the form of sterile solid compositions, which may be dissolved in sterile water or some other sterile injectable medium immediately before use.

The ophthalmic solution in the present invention may be either of an aqueous ophthalmic solution, a non-aqueous ophthalmic solution, a lyophobic ophthalmic solution and a lyophilic ophthalmic solution. In this case, in general, the ophthalmic solution is roughly classified into a case of using an aqueous solvent and a case of using a non-aqueous solvent.

As the aqueous solvent to be used in the present invention, there may be mentioned, for example, a solvent such as sterilized purified water, physiological saline and the like, and a solvent containing various kinds of components necessary for an ophthalmic solution, including various kinds of electrolytic ions such as BSS plus (trade name, produced by Alcon Co.) and the like, a buffer, an isotonicity-imparting agent, glutathione, glucose and the like, or a solvent containing vitamin B12. Also, as the non-aqueous solvent, there may be mentioned, for example, vegetable oils such as cottonseed oil, soybean oil, sesame oil, peanut oil, castor oil, olive oil, camellia oil, rapeseed oil and corn oil, fluid paraffin and the like. The above isotonicity-imparting agent is not limited so long as it is used in this field of the art, and sodium chloride, boric acid, potassium nitrate, D-mannitol, glucose and the like are preferred. The above pH adjuster is not linnited so long as it is used in this field of the art, and boric acid, anhydrous sodium sulfite, hydrochloric acid, sodium hydroxide, sodium citrate, acetic acid, potassium acetate, sodium carbonate, sodium hydrogen carbonate, borax, a buffer (e.g., a citrate buffer, a phosphate buffer, etc.) and the like are particularly preferred. Its amount to be used may be an amount by which the pH of the ophthalmic composition can be adjusted to 3.0 to 8.0. The above viscosity-imparting agent is not limited so long as it is used in this field of the art, and methyl cellulose, hydroxypropyl cellulose, hydroxypropylmethyl cellulose, polyvinyl alcohol, sodium chondroitin sulfate, polyvinyl pyrrolidone and the like are particularly preferred. Its amount to be used may be an amount by which viscosity enough to be dropped from an ophthalmic solution bottle can be imparted, and it may be, for example, 0.001 % to 10 % (W/V).

The above suspending agent is not limited so long as it is used in this field of the art, and Polysorbate 80 (trade name), polyoxyethylene hardened castor oil, polyoxy hardened castor oil, carboxymethyl cellulose and the like are particularly preferred. Its amount to be used may be 0.001 % to 10% (W/V).

The above emulsifier is not limited so long as it is used in this field of the art, and yolk lecithin, Polysorbate 80 and the like are particularly preferred. Its amount to be used may be 0.001 % to 10% (W/V).

The above preservative is not limited so long as it is used in this field of the art, and benzalkonium chloride, benzethonium chloride, chlorobutanol, phenylethyl alcohol, paraoxybenzoate and the like are particularly preferred. Its amount to be used may be 0.001 % to 10% (W/V).

The base is not limited so long as it is used in this field of the art, and petrolatum, gelatinized hydrocarbon, polyethylene glycol, purified lanolin and the like are particularly preferred.

The active compounds can also be in micro-encapsulated form, if appropriate, with one or more pharmaceutically acceptable carriers as noted above. The solid dosage forms of tablets, dragees, capsules, pills, granules and device can be prepared with coatings and shells such as enteric coatings, release controlling coatings and other coatings well known in the pharmaceutical formulating art. In such solid dosage forms the active compound can be admixed with at least one inert diluent such as sucrose, lactose, or starch. Such dosage forms may also comprise, as is normal practice, additional substances other than inert diluents, e.g., tableting lubricants and other tableting aids such a magnesium stearate and microcrystalline cellulose. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents. They may optionally contain opacifying agents and can also be of such composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes. Injectable depot forms are made by forming microencapsulated matrices of the drug in biodegradable polymers such as polylactide-polyglycolide. Depending upon the ratio of drug to polymer and the nature of the particular polymer employed, the rate of drug release can be controlled. Examples of other biodegradable polymers include poly(orthoesters) and poly(anhydrides) Depot injectable formulations are also prepared by entrapping the drug in liposomes or microemulsions which are compatible with body tissues.

In a particular embodiment, the compositions of the invention are administered through controlled drug device made from the biodegradable copolymers poly- lactic-acid (PLA) and/or poly-lacticglycolic acid (PLGA) and the similar, produced by electrospinning technology or equivalent technologies. Cryoprotectants (e.g. glycerol) can be included during electrospinning or equivalent technology, in order to minimize the dehydrating effect of the process. The optimal rate and extent of drug release from these implants are tailored by modifying the PLA PGA polymer ratio. Biodegradable implant dissolve over time are particularly preferred to avoid the need to remove the implant.

The injectable formulations can be sterilized, for example, by filtration through a bacterial- retaining filter or by incorporating sterilizing agents in the form of sterile solid compositions which can be dissolved or dispersed in sterile water or other sterile injectable medium just prior to use. Injectable preparations, for example, sterile injectable aqueous or oleaginous suspensions may be formulated according to the known art using suitable dispersing or wetting agents and suspending agents. The sterile injectable preparation may also be a sterile injectable solution, suspension or emulsion in a nontoxic, parenterally acceptable diluent or solvent such as a solution in 1 ,3- butanediol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution, U.S. P. and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil can be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid are used in the preparation of injectables.

Solid dosage forms for oral administration include capsules, tablets, pills, powders, and granules. In such solid dosage forms, the active compound is mixed with at least one inert pharmaceutically acceptable carrier such as sodium citrate or calcium phosphate and/or a) fillers or extenders such as starches, lactose, sucrose, glucose, mannitol, and salicylic acid; b) binders such as carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidinone, sucrose, and acacia; c) humectants such as glycerol; d) disintegrating agents such as agar-agar, calcium carbonate, potato or tapioca starch, alginic acid, certain silicates, and sodium carbonate; e) solution retarding agents such as paraffin; f) absorption accelerators such as quaternary ammonium compounds; g) wetting agents such as cetyl alcohol and glycerol monostearate; h) absorbents such as kaolin and bentonite clay; and i) lubricants such as talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate, and mixtures thereof. In the case of capsules, tablets and pills, the dosage form may also comprise buffering agents. Solid compositions of a similar type may also be employed as fillers in soft and hard-filled gelatin capsules using lactose or milk sugar as well as high molecular weight polyethylene glycols and the like.

The solid dosage forms of tablets, dragees, capsules, pills, and granules can be prepared with coatings and shells such as enteric coatings and other coatings well known in the pharmaceutical formulating art. They may optionally contain opacifying agents and can also be of a composition that they release the active ingredient(s) only, or preferentially, in a certain part of the intestinal tract in a delayed manner. Examples of embedding compositions which can be used include polymeric substances and waxes. Compositions for rectal administration are preferably suppositories which can be prepared by mixing the compounds of this invention with suitable non- irritating carriers such as cocoa butter, polyethylene glycol or a suppository wax which are solid at ambient temperature but liquid at body temperature and therefore melt in the rectum and release the active compound.

Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1 ,3-butylene glycol, dimethylformamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof.

Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents.

Dosage forms for topical administration include pharmaceutically acceptable emulsions, microemulsions, solutions, suspensions, syrups and elixirs. In addition to the active compounds, the liquid dosage forms may contain inert diluents commonly used in the art such as, for example, water or other solvents, solubilizing agents and emulsifiers such as ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1 ,3-butylene glycol, dimethylformamide, oils (in particular, cottonseed, groundnut, corn, germ, olive, castor, and sesame oils), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, and mixtures thereof. Besides inert diluents, the oral compositions can also include adjuvants such as wetting agents, emulsifying and suspending agents, sweetening, flavoring, and perfuming agents. Dosage forms for topical or transdermal administration of a compound of this invention include ointments, pastes, creams, lotions, gels, powders, solutions, sprays, inhalants or patches. The active component is admixed under sterile conditions with a pharmaceutically acceptable carrier and any needed preservatives or buffers as may be required. Ophthalmic formulation, ear drops, eye ointments, powders and solutions are also contemplated as being within the scope of this invention.

The ointments, pastes, creams and gels may contain, in addition to an active compound of this invention, animal and vegetable fats, oils, waxes, paraffins, starch, tragacanth, cellulose derivatives, polyethylene glycols, silicones, bentonites, silicic acid, talc and zinc oxide, or mixtures thereof.

Powders and sprays can contain, in addition to the compounds of this invention, lactose, talc, silicic acid, aluminum hydroxide, calcium silicates and polyamide powder, or mixtures of these substances. Sprays can additionally contain customary propellants such as chlorofluorohydrocarbons.

Compounds of this invention may also be administered in the form of liposomes. As is known in the art, liposomes are generally derived from phospholipids or other lipid substances. Liposomes are formed by mono- or multi-lamellar hydrated liquid crystals that are dispersed in an aqueous medium. Any non-toxic, physiologically acceptable and metabolizable lipid capable of forming liposomes may be used. The present compositions in liposome form may contain, in addition to the compounds of this invention, stabilizers, preservatives, and the like. The preferred lipids are the natural and synthetic phospholipids and phosphatidylcholines (lecithins) used separately or together.

Methods to form liposomes are known in the art. See, for example, Prescott, Ed., Methods in Cell Biology, Volume XIV, Academic Press, New York, N.V., (1976), p 33 et seq. The phrase "therapeutically effective amount" of the compound of this invention means a sufficient amount of the compound to treat ocular disorders, or to prevent the onset of ocular disorders, at a reasonable benefit/risk ratio applicable to any medical treatment. The specific therapeutically effective dose level for any particular patient will depend upon a variety of factors including the disorder being treated and the severity of the disorder; activity of the specific compound employed; the specific composition employed; the age, body weight, general health, sex and diet of the patient; the time of administration, route of administration, and rate of excretion of the specific compound employed; the duration of the treatment; drugs used in combination or coincidental with the specific compound employed; and like factors well known in the medical arts.

Actual dosage levels of active ingredients in the pharmaceutical compositions of this invention can be varied so as to obtain an amount of the active compound(s) which is effective to achieve the desired therapeutic response for a particular patient, compositions, and mode of administration. The selected dosage level will depend upon the activity of the particular compound, the route of administration, the severity of the condition being treated, and the condition and prior medical history of the patient being treated.

A "pharmaceutically-acceptable derivative" denotes any salt, ester of a compound of this invention, or any other compound which upon administration to a patient is capable of providing (directly or indirectly) a compound of this invention, or a metabolite or residue thereof.

The term "pharmaceutically-acceptable salts" embraces salts commonly used to form alkali metal salts and to form addition salts of free acids or free bases. The nature of the salt is not critical, provided that it is pharmaceutically-acceptable. Suitable pharmaceutically-acceptable acid addition salts may be prepared from an inorganic acid or from an organic acid. Examples of such inorganic acids are hydrochloric, hydrobromic, hydroiodic, nitric, carbonic, sulfuric and phosphoric acid. Appropriate organic acids may be selected from aliphatic, cycloaliphatic, aromatic, arylaliphatic, heterocyclic, carboxylic and sulfonic classes of organic acids, example of which are formic, acetic, adipic, butyric, propionic, succinic, glycolic, gluconic, lactic, malic, tartaric, citric, ascorbic, glucuronic, maleic, fumaric, pyruvic, aspartic, glutamic, benzoic, anthranilic, mesylic, 4- hydroxybenzoic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic, ethanesulfonic, ethanedisulfonic,benzenesulfonic, pantothenic,2- hydroxyethanesulfonic, toluenesulfonic, sulfanilic, cyclohexylaminosulfonic, camphoric, camphorsulfonic, digluconic, cyclopentanepropionic, dodecylsulfonic, glucoheptanoic, glycerophosphonic, heptanoic, hexanoic, 2- hydroxy-ethanesulfonic, nicotinic, 2- naphthalenesulfonic, oxalic, palmoic, pectinic, persulfuric, 2-phenylpropionic, picric, pivalic propionic, succinic, tartaric, thiocyanic, mesylic, undecanoic, stearic, algenic, [beta)- hydroxybutyric, salicylic, galactaric and galacturonic acid. Suitable pharmaceutically-acceptable base addition salts include metallic salts, such as salts made from aluminum, calcium, lithium, magnesium, potassium, sodium and zinc, or salts made from organic bases including primary, secondary and tertiary amines, substituted amines including cyclic amines, such as caffeine, arginine, diethylamine, N- ethyl piperidine, aistidine, glucamine, isopropylamine, lysine, morpholine, N- ethyl morpholine, piperazine, piperidine, triethylamine, trimethylamine. All of these salts may be prepared by conventional means from the corresponding compound of the invention by reacting, for example, the appropriate acid or base with the compound of the invention. When a basic group and an acid group are present in the same molecule, a compound of the invention may also form internal salts

Kits containing compositions

The invention is also directed to a method of administration of the combination. More particularly the active agents of the combination therapy are administered sequentially in either order or simultaneously. When the active agents are administered simultaneously, one skilled in the art will understand that the second agent can be administered some time after the first agent. The particular period of delay between the administration of the individual compounds in the combination can extend to days, hours, minutes or seconds.

The invention also relates to a kit, wherein the individual compounds of the combination (bethanidine and levetiracetam) are disposed in separate containers. The invention also relates to a kit where, additionally to the compounds of the combination, other devices such as injection or application devices, and other materials such as pharmaceutical carriers, are included. The invention also relates to a kit according to any of the foregoing, further comprising integrally thereto or as one or more separate documents, information pertaining to the contents or the kit and the use of the inhibitors.

As used in relation to the invention, the term "treating" or "treatment" and the like should be taken broadly. They should not be taken to imply that an animal is treated to total recovery. Accordingly, these terms include amelioration of the symptoms or severity of a particular condition or preventing or otherwise reducing the risk of further development of a particular condition.

The term "comprising" is meant to be open ended, including the indicated component but not excluding other elements. The phrase "therapeutically-effective" is intended to qualify the amount of each agent, which will achieve the goal of improvement in disorder severity and the frequency of incidence.

It should be appreciated that methods of the invention may be applicable to various species of subjects, preferably mammals, more preferably humans.

Where the plural form is used for compounds, salts, and the like, this is taken to mean also a single compound, salt and the like. Methods of treatment

The invention thus provides a method for treating ocular disorders associated with retinal ganglion cells degeneration such as glaucoma, angle-closure glaucoma, neovascular glaucoma, open-angle glaucoma, low tension glaucoma, glaucoma associated with ocular disorder, glaucomatous visual field constriction, glaucomatous optic atrophy, papilledema, papillitis, ischemia, pressure-independent glaucomatous optic neuropathy, ischemic optic neuropathy, inflammatory optic neuropathy, compressive optic neuropathy, traumatic optic neuropathy, retinitis pigmentosa, retinal detachment, and retinal ischemic disease, age-related macular degeneration, diabetic retinopathy, uveoretinitis, vitreoretinopathy, acute optic neuritis, dominant optic atrophy, Leber's hereditary optic neuropathy, optic nerve injuries, ocular hypertension, central retinal artery occlusion, ischemic central retinal vein thrombosis, retinopathy of prematurity (ROP), retinal ganglion degeneration, optic neuropathy due to a toxic agent or neuropathy caused by adverse drug reactions or vitamin deficiency, and more particularly for the treatment of an ocular disorder selected from the group consisting of glaucomatous visual field constriction, glaucomatous optic atrophy, pressure-independent glaucomatous optic neuropathy, ischemic optic neuropathy, inflammatory optic neuropathy, compressive optic neuropathy, traumatic optic neuropathy and retinal ischemic disease, age-related macular degeneration, diabetic retinopathy, acute optic neuritis, dominant optic atrophy, Leber's hereditary optic neuropathy, optic nerve injuries, retinal ganglion degeneration and optic neuropathy due to a toxic agent or neuropathy caused by adverse drug reactions or vitamin deficiency, in a mammal in need thereof, particularly in a human patient, that includes the step of administering to the mammal, particularly to the human mammal, a therapeutically effective amount, particularly a synergistically effective amount of a combination comprising bethanidine and levetiracetam either in the form of a pharmaceutical composition comprising said combination or in the form of a kit wherein the individual compounds of the combination (bethanidine or its pharmaceutically acceptable salts and levetiracetam or its pharmaceutically acceptable salts) are disposed in separate containers.

In another embodiment, the present combinations may also be used with other types of therapies for treating ocular diseases. In another embodiment, the present combinations may also be used or administered in combination with other drugs for the treatment of glaucoma, including -adrenergic blockers, cholinergic agonists, carbonic anhydrase inhibitors, alpha agonists. As will be appreciated, the dose of a combination of the present invention to be administered, the period of administration, and the general administration regime may differ between subjects depending on such variables as the severity of symptoms, the type of ocular disorder to be treated, the mode of administration chosen, type of composition, size of a unit dosage, kind of excipients, the age and/or general health of a subject, and other factors well known to those of ordinary skill in the art. Administration may include a single daily dose or administration of a number of discrete divided doses as may be appropriate. An administration regime may also include administration of one or more of the active agents, or compositions comprising same, as described herein. The period of administration may be variable. It may occur for as long a period is desired.

Administration may include simultaneous administration of suitable agents or compositions or sequential administration of agents or compositions. In a further embodiment, the compositions and methods described herein may be used prophylactically as a means to prevent the development and/or onset of ocular disorders.

The compounds and methods described herein can be used also as visual protection treatments or preventive treatments.

The following examples further illustrate specific embodiments of the invention; however, the following illustrative examples should not be interpreted in any way to limit the extent of the invention

EXAMPLES EXAMPLE 1 The efficacy of the drug combination of bethanidine on retinal damage was studied in a rat model of glaucoma. Ocular hypertension (OHT) was induced in left eye of Albino Sprague Dawley female rats by laser cauterization of limbar and espiscleral veins as described in Vidal-Sanz, M. et al. Understanding glaucomatous damage: anatomical and functional data from ocular hypertensive rodent retinas. Prog Retin Eye Res 31 , 1 -27 and in Salinas- Navarro, M. et al. Ocular hypertension impairs optic nerve axonal transport leading to progressive retinal ganglion cell degeneration. Exp Eye Res 90, 168- 83. Drugs and vehicle were daily administered during 2 weeks. Phosphate buffered saline (PBS) was employed as a vehicle. Bethanidine was topically administered at a daily dose of one 20 μΙ-drop of a PBS solution comprising 2% w/v of bethanidine instillated on the left eye of the rats. This corresponds to a daily dose of 0.002 mg/kg or 0.012 img/m². Levetiracetam was intraperitoneally administrated at a daily dose of 54 mg/kg or 324 mg/m². Levetiracetam was used at a dilution of 0.054 mg/ L, so 1 pL/g of animal weight were injected to reach the desired concentration.

We examined rat retinal ganglion cell (RGCs) survival in experimental glaucoma in OHT (n=9), in response to the combination of bethanidine plus levetiracetam (n=9), or vehicle treatment (Phosphate buffered saline solution) (n=8). Intraocular pressure (IOP), which is a pathological hallmark of glaucoma, was assessed using a rebound tonometer (TonoPen) between 13:00 and 14:00 before OHT induction as well as 24 hours, 48 hours, 3 days, 5 days, 7 days, 9 days and 14 days after OHT induction. 7 days after OHT induction, fluorogold (FG) was applied to both superior colliculi (SCi), which are the main retino-recipient target regions in the brain, to retrogradely label the RGCs. RGCs with a functional axon transport the FG from the axon terminals in the SCi and store it in their cytoplasm, allowing visualization of the FG through epifluorescence microscope. Therefore, fluorogold tracing indicates the extent of the lesion as described in Salinas- Navarro, M. et al. Ocular hypertension impairs optic nerve axonal transport leading to progressive retinal ganglion cell degeneration. Exp Eye Res 90, 168- 83. All the animals were killed 14 days after the induction of OHT. Left and right retinas were dissected and RGC were immunodetected by means of Brn3a labelling. Brn3a is a transcription factor that is only expressed in RGC that are alive despite being injured, in such a manner that RGC Brna3+ population encompasses those cells that survive OHT (see Sanchez-Migallon MC, Nadal- Nicolas FM, Jimenez-Lopez M, Sobrado-Calvo P, Vidal-Sanz M, Agudo- Barriuso M. 201 1 . Brain derived neurotrophic factor maintains Brn3a expression in axotomized rat retinal ganglion cells. Exp Eye Res. 92:260-267).

The retinas were analysed in an epifluorescence microscope in order to quantify the signal emitted by the FG (blue) and the Brn3a (red). Consecutive individual photographs were taken using a monitored mechanical stage and later assembled together to create a complete image of the entire retina. Each entire retina was the result of 144 individual pictures. The detailed spatial distribution FG+ (traced) or Brn3a+ (immunodetected) RGCs over the entire retinas was obtained through quadrant analysis, and topological^ evaluated by constructing isodensity maps as previously described in Nadal-Nicolas, F.M. et al. Brn3a as a marker of retinal ganglion cells: qualitative and quantitative time course studies in naive and optic nerve-injured retinas. Invest Ophthalmol Vis Sci 50, 3860-8 (2009) .

STATISTICAL ANALYSIS AND RESULTS:

No significant differences in IOP values between groups were observed.

The percentage of RGC-FG+ or RGC-Brn3a+ in left retinas (OHT) was compared with the percentage of labelled cells RGCs in right retinas (control). Moreover, survival ratios were calculated relative to the lesion in each retina: (CGRs-Brn3a+/CGRs-FG+) x 100. This calculus indicates how many RGCs survive the lesion. The extent of the lesion was quantified by measuring the number of RGC-FG+ cells (the higher the number, the lesser the lesion), whereas survival was evaluated by counting the number of RGC-Brn3a+ cells (the higher the number, the higher the survival).

Statistical analysis was performed using the SigmaStat software for Windows, and the significance threshold was set at p<0.05. Bethanidine plus levetiracetam treated-rats displayed higher percentage of RGCs survival compared to OHT (Mann-Whitney test p=0.034 and vehicle-treated rats) and vehicle treated mice (Mann-Whitney test p=0.049 and vehicle-treated rats).

The ratio of RGCs survival revealed a 97.54 % improvement of Bethanidine plus levetiracetam treated animal versus untreated animals or vehicle treated animals (Figure 2).

Claims

1 . A combination comprising bethanidine or its pharmaceutically acceptable salts and levetiracetam or its pharmaceutically acceptable salts.

2. Pharmaceutical composition comprising a combination as defined in claim 1 .

3. A combination as defined in claim 1 or a pharmaceutical composition as defined in claim 2 for use in the treatment of ocular disorders associated with optic neuropathy and/or retinal ganglion cell degeneration.

4. A combination or a pharmaceutical composition for use according to claim 3 wherein the ocular disorder is selected from the group consisting of glaucoma, angle-closure glaucoma, neovascular glaucoma, open-angle glaucoma, low tension glaucoma, glaucoma associated with ocular disorder, glaucomatous visual field constriction, glaucomatous optic atrophy, papilledema, papillitis, ischemia, pressure-independent glaucomatous optic neuropathy, ischemic optic neuropathy, inflammatory optic neuropathy, compressive optic neuropathy, traumatic optic neuropathy, retinitis pigmentosa, retinal detachment, and retinal ischemic disease, age-related macular degeneration, diabetic retinopathy, uveoretinitis, vitreoretinopathy, acute optic neuritis, dominant optic atrophy, Leber's hereditary optic neuropathy, optic nerve injuries, ocular hypertension, central retinal artery occlusion, ischemic central retinal vein thrombosis, retinopathy of prematurity (ROP), retinal ganglion degeneration and optic neuropathy due to a toxic agent or neuropathy caused by adverse drug reactions or vitamin deficiency.

5. Use of a combination as defined in claim 1 or of a pharmaceutical compositions as defined in claim 2 for the manufacture of a medicament for the treatment of ocular disorders associated with optic neuropathy and/or retinal ganglion cell degeneration.

6. Use according to claim 6 wherein the ocular disorder is selected from the group consisting glaucoma, angle-closure glaucoma, neovascular glaucoma, open-angle glaucoma, low tension glaucoma, glaucoma associated with ocular disorder, glaucomatous visual field constriction, glaucomatous optic atrophy, papilledema, papillitis, ischemia, pressure-independent glaucomatous optic neuropathy, ischemic optic neuropathy, inflammatory optic neuropathy, compressive optic neuropathy, traumatic optic neuropathy, retinitis pigmentosa, retinal detachment, and retinal ischemic disease, age-related macular degeneration, diabetic retinopathy, uveoretinitis, vitreoretinopathy, acute optic neuritis, dominant optic atrophy, Leber's hereditary optic neuropathy, optic nerve injuries, ocular hypertension, central retinal artery occlusion, ischemic central retinal vein thrombosis, retinopathy of prematurity (ROP), retinal ganglion degeneration and optic neuropathy due to a toxic agent or neuropathy caused by adverse drug reactions or vitamin deficiency.

7. Method of treating a subject suffering a disorder associated with optic neuropathy and/or retinal degeneration comprising the administration to said subject of a therapeutically effective amount of a combination as defined in claim 1 or of a pharmaceutical composition as defined in claim 2.

8. Method according to claim 7 wherein the ocular disorder is selected from the group consisting of glaucoma, angle-closure glaucoma, neovascular glaucoma, open-angle glaucoma, low tension glaucoma, glaucoma associated with ocular disorder, glaucomatous visual field constriction, glaucomatous optic atrophy, papilledema, papillitis, ischemia, pressure-independent glaucomatous optic neuropathy, ischemic optic neuropathy, inflammatory optic neuropathy, compressive optic neuropathy, traumatic optic neuropathy, retinitis pigmentosa, retinal detachment, and retinal ischemic disease, age-related macular degeneration, diabetic retinopathy, uveoretinitis, vitreoretinopathy, acute optic neuritis, dominant optic atrophy, Leber's hereditary optic neuropathy, optic nerve injuries, ocular hypertension, central retinal artery occlusion, ischemic central retinal vein thrombosis, retinopathy of prematurity (ROP), retinal ganglion degeneration and optic neuropathy due to a toxic agent or neuropathy caused by adverse drug reactions or vitamin deficiency.