Compositions, methods and uses of bucillamine in the treatment a victim exposed to a chemical warfare agent

Abstract

Compositions, methods and uses for treatment of a victim exposed to a chemical agent comprising administering a therapeutically effective amount of bucillamine or a pharmaceutically acceptable salt or solvate thereof to a victim in need thereof. The therapeutically effective amount of bucillamine can be administered as a pretreatment. The method or use wherein the pretreatment can be administered prior to the victim being exposed to the chemical agent.

Description

COMPOSITIONS, METHODS AND USES OF BUCILLAMINE IN THE TREATMENT A VICTIM EXPOSED TO A CHEMICAL WARFARE AGENTFIELD

[0001] The present invention relates to compositions comprising bucillamine and their use for the treatment of a victim exposed to a chemical warfare agent.BACKGROUND

[0002] The Convention on the Prohibition of the Development, Production, Stockpiling and Use of Chemical Weapons and on their Destruction, entered into force on 29 April 1997. prohibits the large-scale use, development, production, stockpiling and transfer of chemical weapons and their precursors, except for very limited purposes (research, medical, pharmaceutical or protective). However, in recent years there have been reports of the use of chemical weapons in armed conflicts which put military personnel at risk. It would be desirable to have a treatment or antidote which can be administered to victims of chemical agent exposure.

[0003] Nerve agents (NA) are organophosphate compounds that cause toxicity through potent acetylcholinesterase (AChE) inhibition, this causes the toxidrome associated with cholinergic overload. One of the characteristic symptoms of nerve agent exposures is benzodiazepine (BZ) treatmentresistant seizures. Despite this, current standard triple therapy for nerve agent casualties is comprised of an oxime, an antimuscarinic, and a BZ anticonvulsant.

[0004] In organophosphate nerve agent poisonings, one of the most difficult to treat symptoms are seizures that rapidly develop treatment resistance to benzodiazepines Benzodiazepines are the first line emergency drug for actively seizing casualties and act as GABA(A) receptor enhancers to restore the excitatory-inhibitory balance in the brain

[0005] Previous in vitro research at DRDC using hippocampal neuronal cultures demonstrated that GABA type A (GABA(A)) receptors were internalized from the plasma membrane into the nerve terminal very quickly following exposure to soman. This was a proposed mechanism for BZ treatment resistance andwas found to be unique to soman when compared to VX. More recently this was repeated in vivo using a soman-induced seizure model in rats and GABA(A) receptor internalization was observed to occur within the three hours after exposure. This confers to seizures unrelated to NA exposure where a subset of the population develop BZ treatment-resistant status epilepticus with evidence of GABA(A) internalization.(0006] Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.SUMMARY OF THE INVENTION

[0007] Bucillamine (N-(mercapto-2-methylpropionyl)-l-cysteine) is a cysteine derivative with 2 thiol groups. The structure of bucillamine is;

[0008] The present disclosure, in one aspect, relates to a method for the treatment of a victim exposed to a chemical agent including chemical warfare agents such as sulfur mustards, nitrogen mustards, nerve agents of G and V type, lewisite and adamsite comprising administering a therapeutically effective or antidote effective amount of bucillamine or a pharmaceutically acceptable salt or solvate thereof, to a victim in need thereof. In certain aspects of methods of the present disclosure, therapeutically effective or antidote effective acceptable compositions of the present disclosure can be administered to humans at a unit dose within range of about 10 mg to about 50 mg, the range of 100 mg to about 200 mg, 1O0mg, and 200 mg and this should provide a therapeutically effective or antidote effective dose. In another aspect, the daily dose is 300 mg per day. In another aspect, the daily does is 600 mg per day. In certain aspects, the unit dose may be higher than 200 mg, In another aspect, the daily dose is 600 mgper day. In certain aspects, the unit dose may be 200 mg to 300 mg. In certain other aspects, the daily dose may be higher than 600 mg per day. In another aspect, the daily dose is 600 mg to 800 mg per day. In another aspect, the daily dose is up to 1000 mg per day. In other aspects, the daily dose is up to 1500 mg per day, up to 2000 mg per day, up to 2500 mg per day, up to 3000 mg per day, 300-600 mg per day, 300-1000 mg per day, 300-1500 mg per day, 300- 2000 mg per day, 300-2500 mg per day, 300-3000 mg per day, 600-1000 mg per day, 600-1500 mg per day, 600-2000 mg per day, 600-2500 mg per day, 600-3000 mg per day. However, the daily dose will necessarily be varied depending upon the victim being treated, the particular route of administration, and the severity of the effects from a chemical warfare agent being treated. Accordingly, the optimum dosage may be determined by the practitioner who is treating any particular patient.

[0009] The present disclosure, in another aspect, relates to a use of a pharmaceutical composition including bucillamine or a pharmaceutically acceptable salt or solvate thereof, together with one or more pharmaceutically acceptable carriers, diluents and excipients for the treatment of a victim having been exposed to a chemical warfare agent, In certain aspects of uses of the present disclosure, pharmaceutically acceptable compositions of the present disclosure can be used at a unit dose within range of about 10 mg to about 50 mg, the range of 100 mg to about 200 mg, 100mg, and 200 mg and this should provide a therapeutically effective or antidote effective dose. However, the daily dose will necessarily be varied depending upon the host treated, the particular route of administration, and the severity of the effects of chemical warfare agent exposure being treated. Accordingly, the optimum dosage may be determined by the practitioner who is treating any particular victim.DETAILED DESCRIPTION

[0010] Throughout this specification the word “comprise", or variations such as “comprises" or “comprising", will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

[0011] For use in therapy a therapeutically effective amount or an antidote effective amount of the bucillamine or pharmaceutically acceptable salts or solvates thereof, may be presented as a pharmaceutical composition. Thus, in a further embodiment the invention provides a pharmaceutical composition of bucillamine or pharmaceutically acceptable salts or solvates thereof in admixture with one or more pharmaceutically acceptable carriers, diluents, or excipients. The carrier(s), diluent(s) or excipient(s) must be acceptable in the sense of being compatible with the other ingredients of the formulation and not deleterious to the recipient thereof.

[0012] When applicable, the compositions of the present invention, including bucillamine may be in the form of and / or may be administered as a pharmaceutically acceptable salt.

[0013] Typically, a pharmaceutically acceptable salt may be readily prepared by using a desired acid or base as appropriate The salt may precipitate from solution and be collected by filtration or may be recovered by evaporation of the solvent,

[0014] Suitable addition salts are formed from acids which form non-toxic salts and examples are hydrochloride, hydrobromide, hydroiodide, sulphate, nitrate, phosphate, hydrogen phosphate, dihydrogen phosphate acetate, maleate, malate, fumarate, lactate, tartrate, citrate, formate, gluconate, succinate, pyruvate, oxalate, oxaloacetate, trifluoroacetate, saccharinate, benzoate, methanesulphonate, ethanesulphonate, benzenesulphonate, p- toluenesulphonate and isethionate.

[0015] Suitable salts may also be formed from bases, forming salts including ammonium salts, alkali metal salts such as those of sodium and potassium, alkaline earth metal salts such as those of calcium and magnesium.

[0016] Pharmaceutically acceptable salts may also be prepared from other salts, including other pharmaceutically acceptable salts, using conventional methods.(0017] Those skilled in the art of organic or coordination chemistry will appreciate that many organic and coordination compounds can form complexes with solvents in which they are reacted or from which they are precipitated or crystallized. These complexes are known as "solvates". For example, a complex with water is known as a ‘hydrate’’ Solvates of bucillamine are within the scope of the present invention.

[0018] In certain embodiments, pharmaceutical compositions of the invention may be formulated for administration by any appropriate route, for example by the oral (including buccal or sublingual), Therefore, the pharmaceutical compositions of the invention may be formulated, for example, as tablets, capsules, powders, granules, lozenges, creams or liquid preparations, such as oral solutions or suspensions. Such pharmaceutical formulations may be prepared by any method known in the art of pharmacy, for example by bringing into association the active ingredient with the carrier(s) or excipient(s).

[0019] Tablets and capsules for oral administration may be in unit dose presentation form, and may contain conventional excipients such as binding agents, for example syrup, acacia, gelatine, sorbitol, tragacanth, or polyvinylpyrrolidone; fillers, for example lactose, sugar, maize-starch, calcium phosphate, sorbitol or glycine; tableting lubricants, for example magnesium stearate, talc, polyethylene glycol or silica; disintegrants, for example potato starch; or acceptable wetting agents such as sodium lauryl sulphate. The tablets may be coated according to methods well known in normal pharmaceutical practice. Oral liquid preparations may be in the form of, for example, aqueous or oily suspensions, solutions, emulsions, syrups or elixirs, or may be presented as a dry product for reconstitution with water or other suitable vehicle before use. Such liquid preparations may contain conventional additives, such as suspending agents, for example sorbitol, methyl cellulose, glucose syrup, gelatine, hydroxyethyl cellulose, carboxymethyl cellulose, aluminium stearate gel or hydrogenated edible fats, emulsifying agents, for example lecithin, sorbitan, monooleate, or acacia; non-aqueous vehicles (which may include edible oils), for example almond oil, oily esters such as glycerine, propylene glycol, or ethyl alcohol; preservatives, for example methyl or propyl p- hydroxybenzoate or sorbic acid, and, if desired, conventional flavouring or colouring agents.

[0020] It should be understood that in addition to the ingredients particularly mentioned above, the formulations may include other agents conventional in the art having regard to the type of formulation in question.

[0021] The compositions of the present invention may be suitable for the treatment of diseases in a human or animal victim. In one embodiment, the victim is a mammal including a human, horse, dog, cat. sheep, cow. or primate. In oneembodiment the victim is a human. In a further embodiment, the victim is not a human.

[0022] As used herein, the term “effective amount1’ means that amount of a drug or pharmaceutical agent that will elicit the biological or medical response of a tissue, system, animal or human that is being sought, for instance, by a researcher or clinician. Furthermore, the term “therapeutically effective amount” means any amount which, as compared to a corresponding subject who has not received such amount, results in improved treatment, healing, prevention, or amelioration of a disease, disorder, or side effect, or a decrease in the rate of advancement of a disease or disorder. The term also includes within its scope amounts effective to enhance normal physiological function.

[0023] As used herein the term "treatment" refers to defending against or inhibiting a symptom, treating a symptom, delaying the appearance of a symptom, reducing the severity of the development of a symptom, and / or reducing the number or type of symptoms suffered by a victim, as compared to not administering a pharmaceutical composition of the invention.

[0024] Accordingly, the present invention, in one embodiment, relates to a method for the treatment of a victim exposed to a chemical agent including chemical warfare agents such as sulfur mustards, nitrogen mustards, nerve agents of G and V type, lewisite and adamsite, comprising administering a therapeutically effective or antidote effective amount of bucillamine or a pharmaceutically acceptable salt or solvate thereof, to a victim in need thereof. In certain aspects of methods of the present invention, therapeutically effective or antidote effective acceptable compositions of the present invention can be administered to humans at a unit dose within range of about 10 mg to about 50 mg, the range of 100 mg to about 200 mg, 100mg, and 200 mg and this should provide a therapeutically effective or antidote effective dose. In another aspect, the daily dose is 300 mg per day. In another aspect, the daily does is 600 mg per day. In certain aspects, the unit dose may be higher than 200 mg. In another aspect, the daily dose is 600 mg per day. In certain aspects, the unit dose may be 200 mg to 300 mg. In certain other aspects, the daily dose may be higher than 600 mg per day. In another aspect, the daily dose is 600 mg to 800 mg per day. In another aspect, the daily dose is up to 1000 mg per day, In other aspects, the daily dose is up to 1500 mg per day, up to 2000 mg per day. up to 2500 mg perday, up to 3000 mg per day, 300-600 mg per day, 300-1000 mg per day. 300- 1500 mg per day, 300-2000 mg per day, 300-2500 mg per day, 300-3000 mg per day, 600-1000 mg per day, 600-1500 mg per day, 600-2000 mg per day, 600-2500 mg per day, 600-3000 mg per day. However, the daily dose will necessarily be varied depending upon the victim being treated, the particular route of administration, and the severity of the effects from a chemical warfare agent being treated. Accordingly, the optimum dosage may be determined by the practitioner who is treating any particular patient,

[0025] The present invention, in another aspect, relates to a use of a pharmaceutical composition including bucillamine or a pharmaceutically acceptable salt or solvate thereof, together with one or more pharmaceutically acceptable carriers, diluents and excipients for the treatment of a victim having been exposed to a chemical warfare agent. In certain aspects of uses of the present invention, pharmaceutically acceptable compositions of the present invention can be used at a unit dose within range of about 10 mg to about 50 mg, the range of 100 mg to about 200 mg, 100mg, and 200 mg and this should provide a therapeutically effective or antidote effective dose However, the daily dose will necessarily be varied depending upon the host treated, the particular route of administration, and the severity of the effects of chemical warfare agent exposure being treated. Accordingly, the optimum dosage may be determined by the practitioner who is treating any particular victim.

[0026] Applicant has conducted a study of the use of bucillamine as a neuroprotective compound administered to a patient to reduce brain injury and augment antiseizure activity. Soman-exposed rats were administered bucillamine and evaluated to determine effect on GABA(A) receptor endocytosis and the effect on diazepam effectiveness to terminate seizures.

[0027] Pre-treatments using n-acetylcysteine (NAC) and bucillamine to provide some neuroprotection were assessed. These compounds were assessed based on ability to reduce brain injury and ability to preserve GABA(A) receptors which were evaluated with late administration of diazepam. The objective of this portion of the study was to provide a compound which will allow benzodiazepines to be effective at terminating seizure activity and possibly further reduce evidence of brain injury. The animals were monitored. Asoxime chloride (HI-6) and atropine methyl nitrate (AMN) were used to prevent lethalityfrom the peripheral effects of soman while having minimal effect on seizures and brain injury due to their limited ability to cross the blood brain barrier. Hi-6 and AMN were administered by intraperitoneal injection (IP) 30 minutes prior to soman exposure. NAC and bucillamine were each tested by administration as a pretreatment (preTx) IP 60 min prior to soman exposure in a volume of less than 0.5 mL. The doses of antioxidant were 100, 200 and 300 mg / kg On one embodiment, the human equivalent doses (HED) based on the rat to human dose conversion (Nair and Jacob, "A simple practice guide for dose conversion between animals and human", J Basic Clin Pharm. 2016 Mar;7(2):27-31 which is incorporated herein by reference in its entirety) are 16,12 mg / kg, 32.25 mg / kg, and 48.39 mg / kg, respectively. Diazepam (1 mg / kg) was administered by intramuscular injection (IM) into the bicep femoris in a volume less than 0.2 mL.

[0028] Number of Animals; 6 soman / preTx + 6 soman / preTx / BZ + 6 sallne / preTx + 6 saline / PreTx / BZ = 24 x 2 compounds x 3 doses = 144 (* 10% contingency of 14) = 158.

[0029] A subset of the animals were assigned to immunohistochemical brain analyses, once the final timepoint was recorded, the animal was placed in an isoflurane induction chamber until deep anesthesia is achieved, -3 minutes. 1 mL Euthanol (240 mg / mL) was injected intraperitoneal and the animals were quickly transported to the perfusion set up where following a pain check the heart was exposed and 100 mL saline was perfused before being fixed with 4% paraformaldehyde using gravity flow rate for 20 minutes. The brain was then excised and preserved.

[0030] The remaining animals were assigned to Western blot and / or biochemical analyses. Again, once the final timepoint was recorded, the animal was placed in an isoflurane induction chamber until deep anesthesia is achieved, -3 minutes, as soon as a pain response is absent immediately decapitate using rat guillotine and extract whole brain. Dissection is conducted within 5 minutes then brain sections are placed in ice cold lysis buffer. Tissue preparation will proceed as appropriate for homogenates and synaptoneurosomes.

[0031] Results of the study indicate that bucillamine is a significantly more effective antioxidant than NAC and has increased efficacy against seizure activity while limiting the anticoagulant and bleeding event liability observed with NAC.

Claims

CLAIMS:1 . A method for the treatment of a victim exposed to a chemical agent comprising administering a therapeutically effective amount of bucillamine or a pharmaceutically acceptable salt or solvate thereof to a victim in need thereof.

2. The method of claim 1 , wherein the chemical agent is a chemical warfare agent.

3. The method of claim 2, wherein the chemical warfare agent is selected from the group consisting of chemical warfare agents such as sulfur mustards, nitrogen mustards, nerve agents of G and V type, lewisite and adamsite.

4. The method of claim 2, wherein the chemical warfare agent is a sulfur mustard.

5. The method of claim 2, wherein the chemical warfare agent is lewisite.

6. The method of claim 2, wherein the chemical warfare agent is soman.

7. The method of claim 2, wherein the therapeutically effective amount of bucillamine is administered in a dose selected from 16,12 mg / kg, 32.25 mg / kg, 48.39 mg / kg, and 10 mg / kg to 50 mg / kg.

8. The method of claim 7, wherein the therapeutically effective amount of bucillamine is administered as a pretreatment.

9. The method of claim 8, wherein the pretreatment is administered prior to the victim being exposed to the chemical agent.

10. Use of a therapeutically effective amount of bucillamine or a pharmaceutically acceptable salt or solvate thereof for treating a victim exposed to a chemical agent comprising administering to a victim in need thereof.

11. The use of claim 10. wherein the chemical agent is a chemical warfare agent.

12. The use of claim 11, wherein the chemical warfare agent is selected from the group consisting of chemical warfare agents such as sulfur mustards, nitrogen mustards, nerve agents of G and V type, lewisite and adamsite.13.The use of claim 11 , wherein the chemical warfare agent is a sulfur mustard.

14. The use of claim 11 , wherein the chemical warfare agent is lewisite.15 The use of claim 11 , wherein the chemical warfare agent is soman.

16. The use of claim 11 , wherein the therapeutically effective amount of bucillamine is administered in a dose selected from 16.12 mg / kg, 32.25 mg / kg, 4839 mg / kg and 10 mg / kg to 50 mg / kg.

17. The use of claim 16. wherein the therapeutically effective amount of bucillamine is used as a pretreatment18. The use of claim 17, wherein the pretreatment is used prior to the victim being exposed to the chemical agent.

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