WO2005120489A2

WO2005120489A2 - Treatment of central nervous system disorders or injuries with d-methionine

Info

Publication number: WO2005120489A2
Application number: PCT/US2005/019462
Authority: WO
Inventors: Prasad Sunkara
Original assignee: Molecular Therapeutics Inc
Current assignee: Molecular Therapeutics Inc
Priority date: 2004-06-04
Filing date: 2005-06-03
Publication date: 2005-12-22
Anticipated expiration: 2006-12-04
Also published as: WO2005120489A3

Abstract

The present invention relates to methods for preventing, treating, or ameliorating neuronal damage resulting from a central nervous system disorder or injury in an animal comprising administering to the animal D-methionine.

Description

TREATMENT OF CENTRAL NERVOUS SYSTEM DISORDERS OR INJURIES WITH D-METHIONINE

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The invention is in the field of medicinal chemistry. In particular, the present invention relates to methods for preventing, treating, or ameliorating neuronal damage resulting from a central nervous system (CNS) disorder or injury in an animal comprising administering to the animal D-methionine.

SUMMARY OF THE INVENTION

[0002] One aspect of the present invention is a method for preventing, treating, or ameliorating neuronal damage resulting from a CNS disorder or injury in an animal comprising administering to the animal D-methionine. Another aspect of the present invention is a method for preventing, treating, or ameliorating neuronal damage resulting from a CNS disorder or injury in an animal comprising administering to the animal D-methionine in combination with one or more therapeutic agents.

[0003] In certain embodiments of the invention, a CNS disorder or injury includes neurodegenerative diseases (e.g., Alzheimer's disease, Huntington's chorea, Parkinson's disease, amyotrophic lateral sclerosis, degenerative ataxias, multiple system atrophy), cerebrovascular diseases (e.g., global or local ischemia, intracerebral hemorrhage, stroke), seizures and epilepsy, viral diseases (e.g., meningitis, encephalitis), multiple sclerosis, brain tumors, and mechanical force injury.

[0004] In preferred embodiments of the invention, a combination of therapeutic agents is administered. In one embodiment of the invention, D- methionine administration can start prior to administration of the one or more therapeutic agents and/or continue during and beyond administration of the one or more therapeutic agents. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 shows the decrease in infarct size after ischemia/reperfusion injury in rats induced by administration of D-methionine.

DETAILED DESCRIPTION OF THE INVENTION

[0006] The present invention relates to a method for preventing, treating, or ameliorating neuronal damage resulting from a CNS disorder or injury in an animal comprising administering to the animal D-methionine. The invention further relates to a method for preventing, treating, or ameliorating neuronal damage resulting from a CNS disorder or injury in an animal comprising administering to the animal D-methionine in combination with other therapeutic agents, which therapeutic agents are currently being used, have been used, or are known to be useful in the prevention, treatment, or amelioration of neuronal damage resulting from a CNS disorder or injury.

[0007] Administration of D-methionine alone or in combination with other therapeutic agents can be after the onset of a CNS disorder or injury. Preferably the administration is as soon as possible after the event begins, e.g., 6 hours or less after the onset of injury. Administration can also be prior to an anticipated injurious event in an attempt to prevent or reduce neuronal damage. For example, if an event is planned in which neuronal damage is known to occur or is likely to occur, e.g., neurosurgery or cardiopulmonary bypass surgery, D-methionine alone or in combination with other therapeutic agents can be administered before and/or during the event. If an animal exhibits symptoms or risk factors for future or continued neuronal damage (e.g., hypertension, smoking, diabetes, history of prior stroke, history of cardiac conditions, lipid disorders, prior seizures, dementia), D-methionine alone or in combination with other therapeutic agents can be administered in a short-term or long-term manner to ameliorate or prevent neuronal damage in the event an CNS injury occurs.

[0008] As used herein, the term "therapeutically effective amount" refers to that amount of the therapeutic agent sufficient to result in prevention of neuronal damage from a CNS disorder or injury, amelioration of one or more symptoms of neuronal damage from a CNS disorder or injury, or reduction of neuronal damage from a CNS disorder or injury. For example, with respect to the treatment of neuronal damage from a CNS disorder or injury, a therapeutically effective amount preferably refers to the amount of a therapeutic agent that reduces the extent of neuronal damage by at least 10%, preferably at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 100%. The extent of neuronal damage can be determined by any method known in the art for visualizing neuronal function, e.g., electroencephalography, magnetic resonance imaging, computerized tomography, contrast angiography, or Doppler ultrasonography.

[0009] The terms "prevent, preventing, and prevention," as used herein, are intended to refer to a decrease in the occurrence of neuronal damage from a CNS disorder or injury. The prevention may be complete, e.g., the total absence of neuronal damage. The prevention may also be partial, such that the amount of neuronal is less than that which would have occurred without the present invention. For example, the extent of neuronal damage using the methods of the present invention may be at least 10%, preferably at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, or at least 100% less than the amount of neuronal damage that would have occurred without the present invention.

[0010] The term "CNS ischemia," as used herein, is intended to refer to the partial or complete reduction of blood flow to one or more areas of the brain or spinal cord. The ischemia can be global, e.g., a generalized reduction in blood flow due to systemic hypotension. The ischemia can also be focal, e.g., due to a disease in one or more cerebral arteries or localized trauma. The ischemia may be the result of stenosis or occlusion of a blood vessel, for example due to a thrombosis, an embolism, or particle.

[0011] The term "neuronal damage," as used herein, is intended to refer to the damage that occurs to any cell type (e.g., neurons, astrocytes, glia) in the CNS as a result of a CNS disorder or injury. For example, a lack of blood flow results in the death of cells by necrosis and/or apoptosis. If the blood flow is not restored within a few minutes infarction, an area of dead tissue, occurs.

[0012] The term "D-methionine," as used herein, is intended to refer to an optically active composition of methionine wherein the compound rotates plane polarized light clockwise (e.g., a dextrorotatory molecule) as measured by a polarimeter. Preferably, the D-methionine has an enantiomeric excess of 1% to 100%. In one embodiment, the D-methionine has an enantiomeric excess of at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%. The D-methionine can be in any form suitable for administration to an animal, including pharmaceutically acceptable salts.

[0013] The term "therapeutic agent," as used herein, is intended to refer to any agent which is known to be useful, or which has been used or is currently being used for the prevention, treatment, or amelioration of neuronal damage from CNS ischemia. See, e.g., Hardman et al, eds., 2002, Goodman & Gilman's The Pharmacological Basis of Therapeutics 10^th Ed., McGraw-Hill, New York, NY for information regarding therapeutic agents which have been or a currently being used for the prevention, treatment, or amelioration of neuronal damage from a CNS disorder or injury.

[0014] Therapeutic agents useful in the methods of the invention include, but are not limited to, acetylcholinesterase inhibitors (e.g., tacrine, donepezil), anti-convulsants (e.g., phenytoin, carbamazepine, felbamate, lamotrigine), interferon-β, glatiramer acetate, methotrexate, mitoxantrone, methylprednisolone, cladribine, levodopa, amantadine, thrombolytic agents (e.g., tissue plasminogen activator, streptokinase, urokinase), anti-thrombotic agents (e.g., warfarin, aspirin, heparin, nadroparin), anti-platelet agents (e.g., ticlodipine, clopidogrel), cholesterol lowering agents (e.g., simvastatin, lovastatin), anti-hypertensive agents (e.g., diuretics, calcium channel blockers, angiotensin converting enzyme inhibitors), and anti-edema agents (e.g., mannitol).

[0015] In one embodiment of the invention, D-methionine is administered to an animal before, during and/or after an injurious event or the onset of a disorder. The D-methionine can be administered 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 12 hours, 18 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, or more prior to the injurious event or disorder. The D- methionine can be administered 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 12 hours, 18 hours, 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, 1 week, or more after the injurious event or disorder. In certain embodiments the D-methionine is administered before, during, and after the injurious event or disorder.

[0016] In one aspect of the invention, one or more therapeutic agents are administered to an animal in addition to the D-methionine. The D-methionine can be administered prior to (e.g., 0.5 hours, 1 hour, 2 hours, 4 hours, 6 hours, 12 hours, 18 hours, 24 hours, 36 hours, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, or more), concurrently with, or after (e.g., 0.5 hours, 1 hour, 2 hours, 4 hours, 6 hours, 12 hours, 18 hours, 24 hours, 36 hours, 2 days, 3 days, 4 days, 5 days, 6 days, 7 days, or more) the administration of one or more therapeutic agents. The D-methionine and the therapeutic agents can be administered by different protocols, e.g., different schedules, different routes of administration, or different doses.

[0017] When used, the one or more therapeutic agents are administered in doses known to one of skill in the art to prevent, treat, or ameliorate neuronal damage resulting from a CNS disorder or injury. The one or more therapeutic agents are administered in pharmaceutical compositions and by methods known to be effective. For example, the therapeutic agents may be administered systemically (e.g., intravenously, orally) or locally.

[0018] The D-methionine is preferably administered at a dose of about 0.5 mg to about 1 g, more preferably from about 50 mg to about 500 mg. In a specific embodiment, an effective amount of D-methionine is 0.5, 1, 2, 3, 4, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 320, 340, 360, 380, 400, 420, 440, 460, 480, 500, 550, 60, 650, 700, 750, 800, 850, 900, 950, 1000 mg or more. In certain embodiments, an effective dose of D-methionine is between about 0.5 mg to about 1 g, more preferably between about 50 mg to about 800 mg, more preferably between about 100 mg to about 600 mg, more preferably between about 200 mg to about 400 mg. The D-methionine can be administered at a frequency sufficient to achieve a therapeutic effect, e.g., once a day, twice a day, three times a day, four times a day. The compound may be administered by any route, including oral, intramuscular, intravenous, parenteral, rectal, nasal, buccal, topical, subcutaneous, or transdermal.

[0019] A person of skill in the art will readily understand that the exact dosing and schedule of administration of D-methionine and other therapeutic compounds can vary due to many factors, including, but not limited to, the age, health, weight, and past medical history of the animal, kind of concurrent treatment, frequency of treatment, route of administration, and the nature of the effect desired.

[0020] One of skill in the art will recognize that these standard doses are for an average sized adult of approximately 70 kg and can be adjusted for the factors routinely considered as stated above.

[0021] The D-methionine may be administered as part of a pharmaceutical composition comprising a pharmaceutically acceptable carrier, wherein the D- methionine is present in an amount which is effective to achieve its intended purpose, i.e., to reduce or prevent neuronal damage. The pharmaceutical composition may further comprise one or more excipients, diluents or any other components known to persons of skill in the art and germane to the methods of formulation of the present invention.

[0022] The term "pharmaceutical composition" as used herein is to be understood as defining compositions of which the individual components or ingredients are themselves pharmaceutically acceptable, e.g., where oral administration is foreseen, acceptable for oral use. [0023] The pharmaceutical composition can be prepared in single unit dosage forms. The dosage forms are suitable for oral, mucosal (nasal, sublingual, vaginal, buccal, rectal), parenteral (intravenous, intramuscular, intraarteriai), or topical administration.

[0024] The pharmaceutical compositions comprising D-methionine of the present invention may further comprise one or more additives. Additives that are well known in the art include, e.g., detackifiers, anti-foaming agents, buffering agents, antioxidants (e.g., ascorbyl palmitate, butyl hydroxy anisole (BHA), butyl hydroxy toluene (BHT) and tocopherols, e.g., α-tocopherol (vitamin E)), preservatives, chelating agents, viscomodulators, tonicifiers, flavorants, colorants odorants, opacifiers, suspending agents, binders, fillers, plasticizers, lubricants, and mixtures thereof. The amounts of such additives can be readily determined by one skilled in the art, according to the particular properties desired.

[0025] Compositions in accordance with the present invention may be employed for administration in any appropriate manner, e.g., orally, e.g., in unit dosage form, for example in a solution, in hard or soft encapsulated form including gelatin encapsulated form, parenterally or topically, e.g., for application to the skin, for example in the form of a cream, paste, lotion, gel, ointment, poultice, cataplasm, plaster, dermal patch or the like, as a coating for a medical device, e.g., a stent, or for ophthalmic application, for example in the form of an eye-drop, -lotion or -gel formulation. Readily flowable forms, for example solutions and emulsions, may also be employed e.g., for intralesional injection, or may be administered rectally, e.g., as an enema.

[0026] Animals which may be treated according to the present invention include all animals which may benefit from administration of the compounds of the present invention. Such animals include humans, pets such as dogs and cats, and veterinary animals such as cows, pigs, sheep, goats and the like.

[0027] The following examples are illustrative, but not limiting, of the methods of the present invention. Other suitable modifications and adaptations of the variety of conditions and parameters normally encountered in medical treatment and pharmaceutical science and which are obvious to those skilled in the art are within the spirit and scope of the invention.

EXAMPLE 1 Prevention and Treatment of Brain Ischemia

[0028] Rats 8-10 weeks of age (Charles River Laboratories) underwent general anesthesia. A ventral midline incision of approximately 2.0 cm was made in the neck. One common carotid arterial (CCA) system was identified and the CCA were dissected from the surrounding tissue. The ipsilateral internal carotid artery (ICA) and external carotid artery (ECA) were exposed to a maximal length. Branches of the right ECA were occluded by electrocautery and the distal portion of the ECA were ligated. The right CCA and ICA were occluded by temporary clamping followed by which the distal end of the ICA was cut to allow for the insertion of a PE-50 catheter. A loose suture was tied around the proximal right ICA after the insertion of the catheter. A nylon suture was then passed through the catheter into the ICA. The suture was inserted approximately 16 mm to a point above the ICA bifurcation. Proper placement of the filament was verified by a reduction in blood flow as measured by laser Doppler flowmetry. The filament was then left in place for approximately 90 minutes. At the end of the 90 minute occlusion period the filament and catheter were withdrawn, the carotid artery was tied off, and the skin incision was closed with surgical staples. This was considered the start of the reperfusion period.

[0029] D-methionine (Aldrich Chemicals, 98% purity) was dissolved in saline on a weight to volume basis and filtered through a 0.2 micron filter. D- methionine and the saline control were administered by intravenous injection via the tail vein in a bolus injection of 1.5 ml. The study design is shown in Table 1.

All time points are post reperfusion.

[0030] Neurological deficit evaluation was conducted at 4 and 24 hours after reperfusion. The neurological findings were scored on the following four- point scale: 0 - no observable deficit 1 - forelimb flexion 2 - forelimb flexion and decreased resistance to lateral push 3 - forelimb flexion, decreased resistance to lateral push, and unilateral circling in three successive trials.

[0031] A rating of 3 was also given when any of the above findings were present along with a decrease in consciousness. [0032] A seizure activity assessment was blindly conducted on study animals at 4 and 24 hours after reperfusion. A modified five-point classification of the Racine Score was used as follows 0 - no seizure 1 - rhythmic mouth and facial movement 2 - rhythmic head nodding 3 - forelimb clonus 4 - rearing and bilateral forelimb clonus 5 - rearing and falling

[0033] Infarct volume was evaluated using TTC staining. Briefly, after an overdose of pentobarbital, rats were killed by decapitation after 24 hours of reperfusion. The brains were quickly removed and placed in ice-cold saline for 5 minutes and then cut into 2-mm coronal slices by Brain Matrix (Brain Tree Scientific). Sections were incubated in 2% TTC (Sigma) dissolved in saline for 15 minutes at 37°C. The stained brain sections were stored in 10% formalin and refrigerated at 4°C for further processing and storage. Coronal sections (2 mm) were placed on a flat bed color scanner (Hewlett-Packard Scanjet 5400C) connected to a computer. The infarct area, outlined in white, was measured by image analysis software (Photoshop 4.0 Adobe Systems). The volume of infarction in each animal was obtained from the product of average slice thickness and sum of infarction area in all brain slices. The area of infarction in cortex and basal ganglia was expressed as a percent area of the whole coronal section.

[0034] Light microscopy was performed to evaluate the morphology of brain tissue from ischemic, treated, and control groups. Brain tissue sections were fixed in 10% buffered formalin (Stephens Scientific, NJ). The tissues were embedded in paraffin and sectioned at 4 μm thickness. Sections were then stained with hematoxylin and eosin to evaluate the morphological changes in brain tissue.

[0035] The data presented in Figure 1 demonstrate the protection provided by D-methionine as seen by the reduction in infarct size and volume. The study demonstrates a reduction in infarct size to a range of from 32 to 47.5% of infarct size in control animals when D-methionine was given either prior to ischemia/reperfusion or as late as 2 hours after MCA occlusion. No behavioral changes, loss in body weight or ischemia induced seizure was observed in any of the groups.

[0036] Having now fully described the invention, it will be understood by those of ordinary skill in the art that the same can be performed within a wide and equivalent range of conditions, formulations and other parameters without affecting the scope of the invention or any embodiment thereof. All patents, patent applications and publications cited herein are fully incorporated by reference herein in their entirety.

Claims

WHAT IS CLAIMED IS:

1. A method for preventing, treating, or ameliorating neuronal damage resulting from a central nervous system (CNS) disorder or injury in an animal in need thereof comprising administering to the animal a therapeutically effective amount of D-methionine.

2. The method of claim 1, wherein said D-methionine is administered intravenously.

3. The method of claim 1, wherein said D-methionine is administered orally.

4. The method of claim 1, wherein said D-methionine is administered at a dose of 0.5 mg to 1 g.

5. The method of claim 1, wherein said CNS disorder or injury is Alzheimer's disease, Huntington's chorea, Parkinson's disease, global or local ischemia, intracerebral hemorrhage, stroke, seizures, epilepsy, meningitis, encephalitis, multiple sclerosis, brain tumors, or mechanical force injury.

6. The method of claim 1, wherein said D-methionine is administered during said CNS disorder or injury.

7. The method of claim 1, wherein said D-methionine is administered after said CNS disorder or injury.

8. The method of claim 1, wherein said D-methionine is administered before said CNS disorder or injury.

9. The method of claim 1, wherein said D-methionine is administered within 6 hours of the onset of said CNS disorder or injury.

10. The method of claim 9, wherein said D-methionine is administered within 2 hours of the onset of said CNS disorder or injury.

11. The method of claim 1, wherein said D-methionine is administered in combination with one or more therapeutic agents.

12. The method of claim 11, wherein said one or more therapeutic agents are selected from the group consisting of acetylcholinesterase inhibitors, anti-convulsants, thrombolytic agents, anti-thrombotic agents, anti- platelet agents, cholesterol lowering agents, anti-hypertensive agents, and anti- edema agents.

13. The method of claim 11, wherein said one or more therapeutic agents are selected from the group consisting of tacrine, donepezil, phenytoin, carbamazepine, felbamate, lamotrigine, interferon-β, glatiramer acetate, methotrexate, mitoxantrone, methylprednisolone, cladribine, levodopam, amantadine, tissue plasminogen activator, streptokinase, urokinase, warfarin, aspirin, heparin, nadroparin, ticlodipine, clopidogrel, simvastatin, lovastatin, diuretics, calcium channel blockers, angiotensin converting enzyme inhibitors, and mannitol.

14. The method of claim 11, wherein said D-methionine is administered prior to said one or more therapeutic agents.

15. The method of claim 11, wherein said D-methionine is administered concurrently with said one or more therapeutic agents.

16. The method of claim 11, wherein said D-methionine is administered after said one or more therapeutic agents.