WO2007039797A1 - Use of cannabinoid receptor-1 antagonist for treating inflammation and arthritis - Google Patents

Abstract

The invention described herein relates to the treatment of inflammation, pain associated with inflammation, and arthritis with cannabinoid receptor-1 (CB-1 ) antagonists.

Description

USE OF CANNABINOID RECEPTOR-1 ANTAGONIST FOR TREATING INFLAMMATION AND ARTHRITIS

CROSS-REFERENCE TO RELATED PATENTS AND PATENT APPLICATIONS This application claims the benefit of U.S. Patent Application Serial No. 60/723,493, filed

October 3, 2005, which is incorporated by reference herein in its entirety.

FIELD OF INVENTION

The present invention relates to the treatment of inflammation, pain associated with inflammation and arthritis with cannabinoid receptor-1 (CB-1) antagonists. BACKGROUND

Cannabis Sativa has been used for medicinal and recreational purposes for about 5000 years. Progress within the cannabinoid research field in the last 50 years has led to significant interest in the use of cannabinoid pharmacology for the treatment of a host of ailments including pain, inflammation, cancer and cachexia. The mechanism of action of cannabinoids are thought to be mediated by cannabinoid receptors at the cell surface. To date, 2 receptors have been identified, CB1 (Nature, 346:561- 564 (1990); Matsuda et.al.) and CB2 (Nature, 365:61-65 (1993); Munro et.al) that couple to the Gi subtype of G-protein signaling pathways. Multiple studies have demonstrated that activation of these receptors inhibit adenylate cyclase activity among other effects. The distribution of these receptors appears to be fairly distinct with CB1 receptors primarily in the CNS and CB2 primarily in the periphery.

Studies to date provide support for the role of cannabinoid receptors in several physiological functions including food consumption and body weight, in which CB1 receptor activation leads to increased food consumption and weight gain (Prostaglandin Leukot. Essent. Fatty Acids, 66:221-233 (2002); Fride et.al.) whereas CB1 receptor blockade reduces food consumption and leads to weight loss (Lancet. 365:1389-1397 (2005); Van Gaal et.al). Moreover, cannabinoids have also been suggested to be immunomodulatory; this effect has been attributed to the involvement of the CB2 receptor regulation of immune cell expansion and trafficking (Prostaglandin Leukot. Essent. Fatty Acids, 66:319-332 (2002); Parolaro et.al., J Leukoc Biol. 76:1002-1009 (2004); Oka et.al., J Biol Chem. 278:24469-24475 (2003) Kishimoto et.al.). Additionally, several studies have also reported the potential use of cannabinoids, specifically agonists or activators of the receptors to alleviate inflammation and pain associated with inflammation. For studies directed to alleviation of inflammation, see, e.g., Rao GK, et al., "Cannabinoid receptor-mediated regulation of intracellular calcium by []9-t.et.rariydrocannabinol in resting T cells," J Leuko Biol, 75:884-892 (2004); Klein TW, et al., "Cannabinoid receptors and helper T cells," J Neuroimmunol, 147, 91-94 (2004); Klein, TW, et al.,. Cannabinoid receptors and immunity," Immunology Today 19:373-381 (1998); Smith SR, et al., "Effects of cannabinoid receptor agonist and antagonist ligands on production of inflammatory cytokines and antiinflammatory interleukin-10 in endotoxemic mice," J Pharm Exp Ther, 293,136-150 (2000); Smith SR, et al., "Modulation of cytokine responses in Corynebacterium parvum-primed endotoxemic mice by centrally administered cannabinoid ligands," Eur J Pharm. 425,73-83 (2001);

Smith SR, et al., "The anti-inflammatory activities of cannabinoid receptor ligands in mouse peritonitis models," Eur J Pharm, 432,107-119 (2001); Lavon I, et al., "A novel synthetic cannabinoid derivative inhibits inflammatory liver damage via negative cytokine regulation," MoJ Pharm, 64,1334-1341 (2003); and Croci T, "Role of cannabinoid CB1 receptors and tumor necrosis factor-^ in the gut and systemic anti-inflammatory activity of SR141716 (Rimonabant) in rodents," Br J Pharm, 140,115-122 (2003). For studies relating to pain associated with inflammation, see, e.g., Pertwee RG. "Cannabinoid receptors and pain," Prog Neurobiol, 63, 569- 611 (2001 ); Cravatt BF, et al., "The endogenous cannabinoid system and its role in nociceptive behavior," lnt J Neurobiol, 61,149-160 (2004); Richardson JD, et al., "Cannabinoids reduce hyperalgesia and inflammation via interaction with peripheral CB1 receptors," Pain, 75,111-119 (1998); Kelly S, et al., "Activation of peripheral cannabinoid CB1 receptors inhibits mechanically evoked responses of spinal neurons in noninflamed rats and rats with hindpaw inflammation," Eur J Neurosci,. 18, 2239-2243 (2003); Clayton N, et al.,. "CB1 and CB2 cannabinoid receptors are implicated in inflammatory pain," Pain, 96, 253-260 (2002); Watts G. "High hopes for cannabinoid analgesia," Br Med J, 329, 257-258 (2004); and Mbvundula EC, et al., "Cannabinoids in pain and inflammation," Inflammopharm, 12, 99-114 (2004).

The current thought surrounding the use of the cannabinoid receptor ligands as it relates to inflammatory disorders and pain disorders have overwhelmingly involved the use of agents that possess agonist activities at the cannabinoid receptors. For the use of cannabinoid receptor ligands relating in inflammatory disorders, see, e.g., Rao GK, et al., J Leuko Biol 75, 884-892 (2004); Klein TW, et al., J Neuroimmunol, 147, 91-94 (2004); and Klein, TW, et al., Immunology Today, 19, 373-381 (1998). For the use of cannabinoid receptor ligands relating to pain disorders, see e.g., Cravatt BF, et al., lnt J Neurobiol, 61,149-160 (2004); Richardson JD, et al.. Pain. 75,111-1 19 (1998); KeIIv S. et al., Eur J Neurosci. 18, 2239-2243 (2003); Clayton N, et al., Pajn, 96, 253-260 (2002); and Watts G.. Br Med J. 329, 257-258 (2004).

However, the data are equivocal in terms of the characteristics of the ligands required for anti-inflammatory activity (e.g., agonist vs. antagonist). See, e.g., Rao GK, et al., J Leuko Biol 75, 884-892 (2004); Klein, TW, et al., J Neuroimmunol, 147, 91-94 (2004); Klein, TW, et al., Immunology Today,19, 373-381 (1998);

Smith SR, et al., J Pharm Exp Ther, 293,136-150 (2000); Smith, SR, et al.,. Eur J Pharm, 425,73-83 (2001); Smith SR, et al.,. Eur J Pharm, 432,107-119 (2001); Lavon I, et al., MoI Pharm, 64:1334-1341 (2003); and Croci T, et al...Br J Pharm, 140,115-122 (2003). With the recent controversy relating to COX-2 inhibitors, there still exists a need for effective and safe anti-inflammatory agents.

SUMMARY

Applicants have discovered that cannabinoid CB1 receptor antagonists produce antiinflammatory activities beyond the suppression of TNFα. The data reported herein demonstrates that CB1 receptor antagonists are active in both the mouse LPS challenge acute inflammation model as well as in the rat carrageenan-induced inflammation model.

The present invention provides a method for treating inflammatory diseases comprising the step of administering to an animal (preferably, a mammal, more preferably a human) in need thereof a therapeutically effective amount of a CB-1 antagonist (preferably, a selective CB-1 antagonist). Preferred inflammatory diseases include arthritis, inflammatory bowel disease and congestive obstructive pulmonary disorder. Preferably, the therapeutically effective amount is an amount sufficient to decrease the concentration of TNFoc or MIP-1oc and/or increase the concentration of IL-10 in the blood serum of the animal. The reduction of TNFoc and/or M1P-1«: that is significant or desirable is 40-60% (preferred), 60-80% (more preferred) and 80-100%

(most preferred). In contrast, the increase in IL-10 that is significant or desirable is 10-35%

(preferred), 35-70% (more preferred) and 75-100% (most preferred).

In another embodiment of the present invention, a method is provided for reducing the symptoms of inflammation (e.g., swelling) comprising the step of administering to an animal (preferably a mammal, more preferably a human) in need thereof a therapeutically effective amount of a CB-1 antagonist (preferably, a selective CB-1 antagonist). Preferably, the therapeutically effective amount is an amount sufficient to inhibit production of PGE₂ and TNFcc.

The reduction of TNFoc or PGE₂ that is significant or desirable is 40-60% (preferred), 60-80%

(more preferred) and 80-100% (most preferred). In yet another embodiment of the present invention, a method is provided for treating inflammatory pain comprising the step of administering to an animal (preferably, a mammal, more preferably, a human) in need thereof a therapeutically effective amount of a CB-1 antagonist (preferably, a selective CB-1 antagonist).

In yet another embodiment of the present invention, a method is provided for treating arthritis (preferably, rheumatoid arthritis) comprising the step of administering to an animal

(preferably, a mammal, more preferably, a human) in need thereof a therapeutically effective amount of a CB-1 antagonist (preferably, a selective CB-1 antagonist).

Each of the methods described above may further comprise the administration of an additional anti-inflammatory agent (described herein below). Definitions

The phrase "therapeutically effective amount" means an amount of a compound of the present invention that (i) treats or prevents the particular disease, condition, or disorder, (ii) attenuates, ameliorates, or eliminates one or more symptoms of the particular disease, condition, or disorder, or (iii) prevents or delays the onset of one or more symptoms of the particular disease, condition, or disorder described herein.

The term "animal" refers to humans (male or female), companion animals (e.g., dogs, cats and horses), food-source animals, zoo animals, marine animals, birds and other similar animal species. "Edible animals" refers to food-source animals such as cows, pigs, sheep and poultry. The phrase "pharmaceutically acceptable" indicates that the substance or composition must be compatible chemically and/or toxicologically, with the other ingredients comprising a formulation, and/or the mammal being treated therewith.

The terms "treating", "treat", or "treatment" embrace both preventative, i.e., prophylactic, and palliative treatment.

The terms "modulated by a cannabinoid receptor" or "modulation of a cannabinoid receptor" refers to the activation or deactivation of a cannabinoid receptor. For example, a ligand may act as an agonist, partial agonist, inverse agonist, antagonist, or partial antagonist.

BRIEF DESCRIPTION OF THE FIGURES Figure 1A, 1 B and 1C illustrate circulating TNFoc, MIP-1oc and IL-10 concentration, respectively, in serum of mice following low endotoxin challenge. Mice were dosed intraperitoneally with 1 mg/kg of compounds 1 hour prior to LPS challenge (100 ng/mouse). Animals were terminated and blood collected 1 hour after LPS administration. The data represents 5 mice per group and reported as mean ±SEM. Figures 2A and 2B illustrate paw swelling and production of PGE₂ and TNFoc, respectively, following carrageenan stimuli in the rat. Rats were dosed intravenously with Compound C followed by carrageenan injection (1 mg/100uL/paw) into the right hind paw. Three hours following challenge, paw swelling was determined and paw exudates isolated for PGE₂ and TNFoc analysis. The data represents 8 rats per group and reported as mean ±SEM Figure 3 illustrates the inflammatory pain response following carrageenan-induced paw inflammation in the rat paw. Rats were dosed intravenously with Compound C followed by carrageenan injection (1 mg/100uL/paw) into the right hind paw. Three hours following challenge, response to mechanical and thermal stimuli were determined. The data represents 6-8 rats per group and reported as mean ±SEM. DETAILED DESCRIPTION

Applicants have discovered that cannabinoid CB1 receptor antagonists produce antiinflammatory activities beyond the suppression of TNFα. The data reported herein demonstrates that CB1 receptor antagonists are active in both the mouse LPS challenge acute inflammation model as well as in the rat carrageenan-induced inflammation model. Both models are standard well-established models that assess inhibition of acute inflammatory responses. Therefore, it is reasonable to believe that CB-1 receptor antagonists would be useful for treating inflammation, pain associated with inflammation and arthritis (in particular, rheumatoid arthritis). Consequently, the CB-1 antagonists described herein (including the compositions thereof) may be used in the manufacture of a medicament for the therapeutic applications described herein. Cannabinoid-1 (CB-1) Receptor Antagonists:

As used herein, the term "CB-1 receptor" refers to a G-protein coupled type 1 cannabinoid receptor. The term "antagonist" includes both full antagonists and partial antagonists, as well as inverse agonists. Preferably, the CB-1 receptor antagonist is selective to the CB-1 receptor. "CB-1 receptor selective" means that the compound has little or no activity to antagonize the cannabinoid-2 receptor (CB-2). More preferably, the CB-1 antagonist is at least about 10 fold selective for the CB-1 receptor in comparison to the CB-2 receptor. For example, the inhibitory concentration (IC₅₀) for antagonizing the CB-1 receptor is about 10 or more times lower than the IC₅₀ for antagonizing the CB-2 receptor.

Suitable CB-1 receptor antagonists include compounds disclosed in U.S. Patent Nos. 5,462,960; 5,596,106; 5,624,941 ; 5,747,524; 6,017,919; 6,028,084; 6,432,984; 6,476,060; 6,479,479; 6,518,264; and 6,566,356;

U.S. Patent Publication Nos. 2003/0114495; 2004/0077650; 2004/0092520; 2004/0122074; 2004/0157838; 2004/0157839; 2004/0214837; 2004/0214838; 2004/0214855; 2004/0214856; 2004/0058820: 2004/0235926; 2004/0259887; 2005/0080087; 2005/0026983 and 2005/0101592;

PCT Patent Publication Nos. WO 03/075660; WO 02/076949; WO 01/029007; WO 04/048317; WO 04/058145; WO 04/029204; WO 04/012671 ; WO 03/087037; WO 03/086288; WO 03/082191 ; WO 03/082190; WO 03/063781 ; WO 04/012671 ; WO 04/013120; WO 05/020988; WO 05/039550; WO 05/044785; WO 05/044822; and WO 05/049615:

PCT Patent Application Serial Nos. PCT/IB2004/004050 filed on December 6, 2004; PCT/IB2004/004017 filed on December 6, 2004; PCT/IB2004/004023 filed on December 6, 2004; and PCT/IB2004/004019 filed on December 6, 2004; and

U.S. Provisional Application Nos. 60/523937 filed on November 21 , 2003; 60/529908 filed on December 16, 2003; 60/529909 filed on December 16, 2003; 60/529910 filed on

December 16, 2003; 60/530012 filed on December 16, 2003; and 60/564648 filed on April 21 , 2004.

All of the above patents and patent applications are incorporated herein by reference. Preferred CB-1 receptor antagonists for use in the methods of the present invention include: rimonabant (SR141716A also known under the tradename Acomplia™) is available from Sanofi-Synthelabo or can be prepared as described in U.S. Patent No. 5,624,941 ; /V- (piperidin-i-yO-i^^-dichlorophenyO-δ^-iodophenyO^-methyl-I H-pyrazole-S-carboxamide (AM251 ) is available from Tocris™, Ellisville, MO; [5-(4-bromophenyl)-1-(2,4-dichloro-phenyl)-4- ethyl-Λ/-(1-piperidinyl)-1H-pyrazole-3-carboxamide] (SR147778) which can be prepared as described in US Patent No. 6,645,985; Λ/-(piperidin-1-yl)-4,5-diphenyl-1-methylimidazole-2- carboxamide, Λ/-(piperidin-1-yl)-4-(2,4-dichlorophenyl)-5-(4-chlorophenyl)-1-methylimidazole-2- carboxamide, Λ/-(piperidin-1-yl)-4,5-di-(4-methylphenyl)-1-methylimidazole-2-carboxamide, N- cyclohexyM.δ-di^-methylphenyO-i-methylimidazole^-carboxamide, /V-(cyclohexyl)-4-(2,4- dichlorophenyl)-5-(4-chlorophenyl)-1 -methylimidazole-2-carboxamide, and Λ/-(phenyl)-4-(2,4- dichlorophenyl)-5-(4-chlorophenyl)-1-methylimidazole-2-carboxamide which can be prepared as described in PCT Patent Publication No. WO 03/075660; the hydrochloride, mesylate and besylate salt of 1 -[9-(4-chloro-phenyl)-8-(2-chloro-phenyl)-9H-purin-6-yl]-4-ethylamino-piperidine- 4-carboxylic acid which can be prepared as described in U.S. Patent Publication No. 2004/0092520; i-p^-chloro-phenyO-δ^-chloro-phenyO^-methyl-pyrazolofi .δ-alli .S.δltriazin- 4-yl]-3-ethylamino-azetidine-3-carboxylic acid amide and 1-[7-(2-chloro-phenyl)-8-(4-chloro- phenyl^-methyl-pyrazolofi .S-aJII .S.δ^riazin^-ylj-S-methylamino-azetidine-S-carboxylic acid amide which can be prepared as described in U.S. Patent Publication No. 2004/0157839; 3-(4- chIoro-phenyl)-2-(2-chloro-phenyl)-6-(2,2-difluoro-propyl)-2,4,5,6-tetrahydro-pyrazolo[3,4- c]pyridin-7-one, 2-(2-chloro-phenyl)-3-(4-ethyl-phenyl)-5-(2,2,2-trifluoro-ethyl)-4,5-dihydro-2H- pyrrolo[3,4-c]pyrazol-6-one, and 2-(2-chloro-phenyl)-3-(4~isopropyl-phenyl)-5-(2,2,2~trifluoro- ethyI)-4,5-dihydro-2H-pyrrolo[3,4-c]pyrazol-6-one which can be prepared as described in U.S. Patent Publication No. 2004/0214855; 3-(4-chloro-phenyl)-2-(2~chIoro-phenyl)-7-(2,2-difluoro- propyl)-6,7-dihydro-2H,5H-4-oxa-1 ,2,7-triaza-azulen-8-one which can be prepared as described in U.S. Patent Publication No. 2005/0101592; 2-(2-chloro-phenyl)-6-(2,2,2-trifluoro-ethyl)-3-(4- trifluoromethyl-phenyl)-2,6-dihydro-pyrazolo[4,3-d]pyrimidin-7-one which can be prepared as described in U.S. Patent Publication No. 2004/0214838; (S)-4-chloro-N-{[3-(4-chloro-phenyl)-4- phenyl-4,5-dihydro-pyrazol-1-yl]-methylamino-methylene}-benzenesulfonamide (SLV-319) and (S)-N-{[3-(4-chloro-phenyl)-4-phenyl-4,5-dihydro-pyrazol-1-yl]-methylamino-methylene}-4- trifluoromethyl-benzenesulfonamide (SLV-326) which can be prepared as described in PCT Patent Publication No. WO 02/076949; N-piperidino-5~(4-bromophenyl)-1-(2,4~dichlorophenyl)-4- ethylpyrazole-3-carboxamide which can be prepared as described in U.S. Patent No. 6,432,984; 1-[bis-(4-chloro-phenyl)-methyl]-3-[(3,5-difluoro-phenyl)-methanesulfonyl-methylene]-azetidine which can be prepared as described in U.S. Patent No. 6,518,264; 2-(5-(trifluoromethyl)pyridin- 2-yloxy)-N-(4-(4-chlorophenyl)-3-(3-cyanophenyl)butan-2-yl)-2-methylpropanamide which can be prepared as described in PCT Patent Publication No. WO 04/048317; 4-{[6-methoxy-2-(4- methoxyphenyl)-1-benzofuran-3-yl]carbonyl}benzonitrile (LY-320135) which can be prepared as described in U.S. Patent No. 5,747,524; 1-[2-(2,4-dichlorophenyl)-2~(4-fluorophenyl)- benzo[1 ,3]dioxole-5-sulfonyl]-piperidine which can be prepared as described in WO 04/013120; and [S-amino-δ^-chlorophenyO-θ^^-dichlorophenyO-furo^.S-blpyridin^-yO-phenyl- methanone which can be prepared as described in WO 04/012671.

A typical formulation is prepared by mixing the CB-1 receptor antagonist with a carrier, diluent or excipient. Suitable carriers, diluents and excipients are well known to those skilled in the art and include materials such as carbohydrates, waxes, water soluble and/or swellable polymers, hydrophilic or hydrophobic materials, gelatin, oils, solvents, water, and the like. The particular carrier, diluent or excipient used will depend upon the means and purpose for which the compound of the present invention is being applied. Solvents are generally selected based on solvents recognized by persons skilled in the art as safe (GRAS) to be administered to a mammal. In general, safe solvents are non-toxic aqueous solvents such as water and other nontoxic solvents that are soluble or miscible in water. Suitable aqueous solvents include water, ethanol, propylene glycol, polyethylene glycols (e.g., PEG400, PEG300), etc. and mixtures thereof. The formulations may also include one or more buffers, stabilizing agents, surfactants, wetting agents, lubricating agents, emulsifiers, suspending agents, preservatives, antioxidants, opaquing agents, glidants, processing aids, colorants, sweeteners, perfuming agents, flavoring agents and other known additives to provide an elegant presentation of the drug or aid in the manufacturing of the pharmaceutical product (i.e., medicament). The formulations may be prepared using conventional dissolution and mixing procedures. For example, the bulk drug substance (the compound or stabilized form of the compound (e.g., complex with a cyclodextrin derivative or other known complexation agent)) is dissolved in a suitable solvent in the presence of one or more of the excipients described above. The compound is typically formulated into pharmaceutical dosage forms to provide an easily controllable dosage of the drug and to give the patient an elegant and easily handleable product. The CB-1 receptor antagonist may be formulated into a single dosage form or separate dosage forms. To enhance dissolution rates, it may be advantageous to disperse poorly water-soluble compounds in a suitable dispersant prior to formulating into a dosage form. For example, the water-insoluble or partially water-insoluble compound may be spray-dried in the presence of a solubilizing or dispersing agent. See, e.g., Takeuchi, Hirofumi, et al., J Pharm Pharmacol, 39, 769-773 (1987). Other techniques for improving bioavailability of poorly water-soluble compounds are described in Verreck, G., et al., J Pharm Sci, 93(5), 1217-1228 (2004).

For oral administration the pharmaceutical composition is generally administered in discrete units. For example, typical dosage forms include tablets, dragees, capsules, granules, sachets and liquid solutions or suspensions where each contain a predetermined amount of the active ingredient(s) in the form of a powder or granules, or as a solution or a suspension in an aqueous liquid, a non-aqueous liquid, an oil-in-water emulsion or a water-in-oil liquid emulsion. Compressed tablets may be prepared by compressing the active ingredient(s) in a free- flowing form such as a powder or granules with a binder, lubricant, inert diluent, surface active agent and/or dispersing agent.

Liquid dosage forms for oral administration include pharmaceutically acceptable emulsions, solutions, suspensions, syrups, and elixirs. In addition to the active ingredient(s), the liquid dosage form may contain inert diluents commonly used in the art, such as water or other solvents, solubilizing agents and emulsifiers, as for example, ethyl alcohol, isopropyl alcohol, ethyl carbonate, ethyl acetate, benzyl alcohol, benzyl benzoate, propylene glycol, 1 ,3-butylene glycol, dimethylformamide, oils (e.g., cottonseed oil, groundnut oil, corn germ oil, olive oil, castor oil, sesame seed oil and the like), glycerol, tetrahydrofurfuryl alcohol, polyethylene glycols and fatty acid esters of sorbitan, or mixtures of these substances, and the like. Besides such inert diluents, the composition can also include adjuvants, such as wetting agents, emulsifying and suspending agents, sweetening, and flavoring agents.

Suspensions, in addition to the active ingredients, may further comprise suspending agents, e.g., ethoxylated isostearyl alcohols, polyoxyethylene sorbitol and sorbitan esters, microcrystalline cellulose, aluminum metahydroxide, bentonite, agar-agar, and tragacanth, or mixtures of these substances, and the like.

The pharmaceutical composition (or formulation) for application may be packaged in a variety of ways depending upon the method used for administering the drug. Generally, an article for distribution includes a container having deposited therein the pharmaceutical formulation in an appropriate form. Suitable containers are well-known to those skilled in the art and include materials such as bottles (plastic and glass), sachets, ampoules, plastic bags, metal cylinders, and the like. The container may also include a tamper-proof assemblage to prevent indiscreet access to the contents of the package. In addition, the container has deposited thereon a label that describes the contents of the container. The label may also include appropriate warnings. The compounds can be administered by any method which delivers the compounds preferentially to the desired tissue (e.g., brain, renal or intestinal tissues). These methods include oral routes, parenteral, intraduodenal routes, transdermal, etc. Generally, the compounds are administered orally in single (e.g., once daily) or multiple doses. The amount and timing of compounds administered will, of course, be dependent on the subject being treated, on the severity of the affliction, on the manner of administration and on the judgment of the prescribing physician. Thus, because of patient to patient variability, the dosages given herein are a guideline and the physician may titrate doses of the drug to achieve the treatment that the physician considers appropriate for the patient. In considering the degree of treatment desired, the physician must balance a variety of factors such as age of the patient, presence of preexisting disease, as well as presence of other diseases (e.g., cardiovascular disease).

A daily dose of the CB-1 receptor antagonist is generally between about 0.01 mg to about 10 mg per kilogram of body weight, preferably between about 1 mg to about 10 mg per kilogram of body weight, more preferably between about 0.1 mg to about 1 mg per kilogram of body weight, most preferably between about 0.01 mg to about 0.1 mg per kilogram of body weight.

In certain situations, it may be advantageous to combine the CB-1 receptor antagonist with an additional anti-inflammatory agent for treating the diseases, conditions or disorders described herein. Suitable anti-inflammatory agents include COX-2 inhibitors (e.g., Vioxx™, Celebrex™ and Bextra™); non-selective anti-inflammatory agents (ibuprofen, naproxen), acetaminophen, and steroids such as prednisolone, and budesonide. Other agents that may be used in combination to increase the efficacy of CB1 antagonists for the above indications include selective serotonin reuptake inhibitors (SSRIs, also known as serotonin boosters), such as Cipramil™ or Celexa™ (citalopram), Effexor™ (venlafaxine HCI), Elavil™ (amitriptyline), fluvoxamine maleate, Lexapro® (escitalopram oxalate), _Paxil™ or Aropax™. (paroxetine), Prozac™ (fluoxetine), Sarafem™ (fluoxetine HCI), Zyban™ or Wellbutrin™ (bupropion HCI) and Zoloft™ (sertraline HCI), and selectrive seritonin and noradrenaline reuptake inhibitors (SSNRIs), such as Cymbalta™ (duloxetine) and Effexor™ (venlafaxine).

EXAMPLES

The following compounds used in the experiments illustrated below may be prepared as described in the listed disclosures or purchased from the corresponding vendors.

Compound A N -(piperidin-1-yl)-1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-1 H- pyrazole-3-carboxamide AM251 available from Tocris™, Ellisville, MO.

Compound B N-(piperidin-1-yl)-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)- 4-methyl-1 H-pyrazole-3-carboxamide hydrochloride SR141716A or Rimonabant also known under the tradename Acomplia™ available from Sanofi-Synthelabo Inc., New York, NY; or prepared as described in U.S. Patent No. 5,624,941 Compound C 1-[7-(2-Chloro-phenyl)-8-(4-chloro-phenyl)-2-methyl- pyrazolo[1 ,5-a][1 ,3,5]triazin-4-yl]-3-methylamino-azetidine-3- carboxylic acid amide was prepared as described in U.S. Publication No. 2004/0157839 (incorporated herein by reference)

Compound D (6-lodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1/-/-indol-3-yl)(4- methoxyphenyl)methanone

AM630 available from ALEXIS Biochemicals, San Diego, CA

Both the acute inflammatory and carrageenan-induced inflammation models were used to test the inflammatory response of the test compounds (e.g., CB-1 antagonists). In the acute inflammatory response paradigm (LPS challenge), the key cytokine, tumor necrosis factor α (TNFα) was used as an indicator of the inflammatory response. In the rat carrageenan-induced inflammation model, both paw swelling, and the production of PGE₂ and TNFα in the paw were used as indicators of the inflammatory response.

Inflammation Activity

Three different CB-1 antagonists (Compounds A, B and C) were tested in the following models, as well as a comparative CB-2 antagonist (Compound D)

Acute Inflammation Model

The following standard mouse model was used for measuring acute inflammation. Lipopolysaccharide (LPS)-lnduced TNF<χ Production in BALB/c Mice: Ten-week-old female BALB/c mice from Charles River Laboratory were used. Mice were fasted 18 hours prior to dosing with the test compound and allowed free access to water throughout the experiment. Animal care, use and handling procedures were approved by the Institutional Animal Care and Use Committee (IACUC) and adhere to the American Association for the Accreditation of Laboratory Animal Care (AALAC) guidelines. Each treatment group consisted of 5 mice.

Test compounds were prepared in dimethylsulfoxide (DMSO):emulphor:saline (1 :1 :18). Compounds or vehicle alone were administered i.p. in 0.1 ml volume. LPS, at 100 ng/mouse, were administered 1 hour later by intravenous injection into the tail vein in 0.2 ml sterile saline. Blood was collected in serum separator tubes via cardiac puncture or orbital bleed 1 hour after LPS injection. Blood was allowed to clot, and serum obtained by centrifugation. Serum was stored at -80⁰ C until assayed. This is a non-lethal dose of LPS, and therefore no adverse, reportable events, occurred.

Acute Inflammation and Pain Model

The following standard rat model was used to measure acute inflammatory pain and oedema. Carrageenan-induced paw inflammation and hyperalgesia:

Male Sprague-Dawley rats weighing 180-22Og were used from an approved source (Harlan, Indianapolis, IN). Prior to testing, rats were fasted overnight (16-24 hours). Carrageenan was injected with a 27 ga. needle (0.1ml volume 1-2 mg carrageenan/paw) into one hindpaw/rat causing a hyperalgesic state and paw oedema. Test compounds, or appropriate vehicle were administered by intraperitoneal injection either prior to or after subplantar injection of the carrageenan stimulus. No reportable adverse events were found to occur in this model.

The anti-inflammatory activity of test compounds was determined as oedema measured by a UGO Basile water plethysmometer (volume displacement). The paw volume, due to oedema, increases approximately 1 ml after injection of the carrageenan. Withdrawal latencies and paw oedema were measured between 15 minutes to 3hours after the subplantar injection of carrageenan. At the conclusion of the above measurements, animals were terminated for analysis of inflammatory mediators in the paw exudates.

Results

As reported in Table 1 below, all three CB-1 receptor antagonist chemotypes showed a consistent decrease in TNFcc (see, Figure 1a), decrease in MIP-1oc (see, Figure 1 b) and increase in IL-10 (see, Figure 1c) which demonstrate that CB-1 receptor antagonists (Compounds A, B, and C) have anti-inflammatory activity in vivo following LPS challenge in mice. Unlike the CB-1 receptor antagonists, no efficacy was observed for the selective CB-2 receptor antagonist (Compound D: AM630).

Table 1A (TNFoc)

Table 1 C (IL-10)

The data listed in Tables 1A, 1 B and IC (and graphically illustrated in Figures 1A, 1 B and 1 C) suggest that CB-1 antagonism leads to a profile of cytokines that may result to an antiinflammatory shift. In fact, this is the first report to demonstrate CB-1 antagonists reduce MIP-1 α following an inflammatory challenge. Therefore, it is reasonable to believe that CB-1 antagonists would be useful in inflammatory disorders that involve increased MIP-1 α, TNFα and reduced IL10. Taking into account the overall profile of cytokines modulated by CB-1 antagonists, it is reasonable to believe that CB-1 antagonists provide a novel intervention/mechanism in the treatment of inflammatory diseases such as arthritis, inflammatory bowel disease and congestive obstructive pulmonary disorder. In addition, the data presented in Tables 2A and 2B below also suggests that CB1 antagonists would be useful in reducing the mediators and symptoms of inflammation including swelling (see also, Figure 2A and 2B). Table 2A

(Mediators)

Table 2B (Swelling)

As discussed in the background above, previous studies have suggested that cannabinoid agents may be used to alleviate pain associated with inflammation. However, the use of cannabinoid agents to impact pain disorders has overwhelmingly involved the use of agents that possess agonist activities at the cannabinoid receptors. Therefore, it is counterintuitive and unexpected that CB1 antagonists could lead to pain suppression. The data reported below demonstrates that a CB1 receptor antagonist (Compound C) is analgesic in the rat carrageenan-induced hyperalgesia model. Based on these findings, it is reasonable to believe that cannabinoid receptor antagonists produce analgesic activities due to pain associated with inflammation.

Acute Inflammatory Pain Model In the acute inflammatory pain model, an inflammation-inducing agent (carrageenan) was administered in the plantar surface of the rat hind paw to initiate pain and swelling. This model has been shown to be effective in the assessment of anti-inflammatory and analgesic agents. See, Hargreaves K, et al., "A New and Sensitive Method for Measuring Thermal Nociception in Cutaneous Hyperalgesia," Pain, 32, 77-88 (1988). The following model is the standard model for acute inflammatory pain and oedema.

Carrageenan-induced h yperalgesia:

Male Sprague-Dawley rats weighing 180-22Og were used from an approved source(Harlan, Indianapolis, IN)] Prior to testing, rats were fasted overnight (16-24 hours). Carrageenan was injected with a 27 ga. needle (0.1 ml volume 1-2 mg carrageenan/paw) into one hindpaw/rat causing a hyperalgesic state and paw oedema. Test compounds, or appropriate vehicle were administered by intraperitoneal injection either prior to or after subplantar injection of the carrageenan stimulus. No reportable adverse events were found to occur in this model.

Analgesia was monitored via two behavioral endpoints. In the thermal hyperalgesia mode, rats were placed in a clear plastic chamber with a transparent glass floor. A radiant heat source (a high intensity projector lamp bulb) , positioned under the chamber floor, was sequentially applied to each hindpaw. Withdrawal latency was the endpoint and it is defined as the time between onset of light and the behavioral response of lifting the paw. The difference between the withdrawal latency of the non-injected hindpaw and the carrageenan-injected hindpaw was the measure of thermal hyperalgesia. After induction of oedema, withdrawal latencies typically go from approximately 15 to 2 seconds. The maximum exposure was 20 seconds. To avoid potential acclimation to pain threshold, no more than 5 measurements per rat were taken. Therefore, animals were exposed to the light source only 1-5 times/paw/animal/experiment.

Responses to noxious mechanical stimuli, mechanical hyperalgesia, were assessed in conscious rats using the Randall-Selitto test. Rats were restrained in a gauze wrap and pressure was applied to the dorsal surface of the paw with a conical piston using an Analgesy- Meter (Stoelting Instruments, Wood Dale, IL). Pressure was applied until the rat reacted with a withdrawal response by struggling or vocalization using a maximum cutoff value of 250 g.

Results

The data reported in Table 3 below and shown graphically in Figure 3 supports the proposition that CB1 antagonists would be useful in the treatment and management of inflammatory pain. As discussed in the Background above, previous studies focused on the use of cannabinoid agonist in the treatment of pain. It is likely that the pain suppression observed in the studies presented herein is secondary to CB1 antagonism leading to anti-inflammatory activity (see, Figures 1 A, 1 B, 1 C, 2A and 2B). Clearly, the data reported herein demonstrate the utility of CB1 antagonists in pain intervention.

Table 3

Rheumatoid Arthritis

In the acute inflammatory response paradigm (LPS challenge), the key cytokine, tumor necrosis factor α (TNFα) is used as an indicator of the inflammatory response (see, Figure 1a). TNFα has been implicated in the pathogenesis of rheumatoid arthritis (RA), as well as joint inflammation in rodent models of the disease. See, e.g., Keffer J, et al., "Transgenic mice expressing human tumor necrosis factor: a predictive genetic model of arthritis," EMBO J, 10, 4025 (1991); and Feldmann M, et al., "Role of cytokines in rheumatoid arthritis," Ann Rev Immunol, 14, 397 (1996). .Proteins that neutralize TNFα activity such as the soluble human TNF receptor, etanercept, and the anti-human TNF monoclonal antibody, infliximab, suppress inflammatory signs and symptoms in both rheumatoid arthritis in patients as well as in preclinical models. See, e.g., Moreland L et al., "Treatment of rheumatoid arthritis with a recombinant human tumor necrosis factor soluble receptor. N Engl J Med, 337, 141 (1997); Miani R, et al., "Beneficial effects of tumor necrosis factor alpha blockade in rheumatoid arthritis, "Clin. Exp. Immunol, 101, 207 (1995); Joosten L, M. et al., "Anticytokine treatment of established type Il collagen-induced arthritis in DBA/1 mice," Arthritis Rheum, 39, 797 (1996); and Williams R, et al.. "Successful therapy of collagen induced arthritis with TNF receptor-lgG fusion protein and combination with anti- CD4," Immunology," 84, 433 (1995). Therefore, based on the data presented in Table 1 , the study was extended to test the ability of a CB1 antagonist to inhibit the development and progression of arthritis in a well-accepted preclinical model of arthritis (mouse collagen induced arthritis - mCIA)

Arthritis Model Briefly, DBA/1 mice (Jackson Labs, Bar Harbor, Maine) were immunized with type Il collagen (CII) in complete Freund's adjuvant. The immune response to CII involves both humoral and cellular mechanisms and the cellular response is T helper 1 -mediated. Mouse CIA is characterized by rapid onset of clinical joint inflammation, resulting in destruction of joint tissues and cartilage/bone erosions. In the study reported here, male DBA1 Lac/J mice were immunized with bovine CII. The animals were boosted with bovine CII 21 days following the initial immunization and they were started on treatment regiments. Starting on the 22^nd day, the animals were monitored daily for clinical scores (signs and symptoms of arthritis), percent incidence and number of limbs demonstrating arthritis through the course of the experiment. The data represents 12 animals per group and reported as mean ±SEM.

The data shown below in Table 4 demonstrate that the CB1 antagonist (Compound C) may reduce the clinical score (signs and symptoms) and incidence (development and progression) of arthritis. Activity of compounds in this model have been proposed to predict the clinical efficacy of these compounds in the disease modification of rheumatoid arthritis. The data clearly supports the proposition that CB1 antagonists may possess the disease modifying properties for the treatment of arthritis. Table 4

Claims

CLAIMS What is claimed is

1. A method for treating an inflammatory disease comprising the step of administering to an animal in need thereof a therapeutically effective amount of a CB-1 antagonist, wherein said inflammatory disease is selected from the group consisting of arthritis, inflammatory bowel disease, and congestive obstructive pulmonary disorder.

2. The method of Claim 1 wherein said inflammatory disease is arthritis.

3. The method of Claim 2 wherein said arthritis is rheumatoid arthritis.

4. The method of Claim 2 or 3 further comprising the step of administering a COX-2 inhibitor, a non-selective anti-inflammatory agent, acetaminophen, or a steroid.

5. The method of Claim 4 wherein said COX-2 inhibitor is Celebrex, said nonselective anti-inflammatory agent is ibuprofen or naproxen, and said steroid is prednisone, prednisolone, or budesonide.

6. The method of Claim 1 wherein said inflammatory disease is inflammatory bowel disease.

7. The method of Claim 5 further comprising the step of administering loperamide or aminosalicylates (mesalamine, sulfasalazine) or steroids (prednisone, prednisolone, budesonide).

8. The method of Claim 1 wherein said inflammatory disease is congestive obstructive pulmonary disorder. ,

9. The method of Claim 8 further comprising the step of administering a bronchodilator; beta-2 agonists such as salbutamol, albuterol, salmeterol, clenbuterol, pirbuterol, bitolterol or formoterol, inhaled steroids such as fluticasone, budesonide or flunisolide, or anti- leukotrienes such as zafirlukast, pranlukast, montelukast and zilueton.

10. A method for treating inflammatory diseases comprising the step of administering to an animal in need thereof a therapeutically effective amount of a CB-1 antagonist, wherein said therapeutically effective amount is an amount sufficient to decrease the concentration of TNFoc or MIP-1<χ of said animal.

11. The method of Claim 10 wherein said therapeutically effective amount is sufficient to increase the concentration of 1L-10 in the blood serum of said animal.

12. A method for reducing the symptoms of inflammation comprising the step of administering to an animal in need thereof a therapeutically effective amount of a CB-1 antagonist.

13. The method of Claim 7 wherein said therapeutically effective amount is an amount sufficient to inhibit production of PGE₂ and TNFoc.

14. The method of Claim 13 further comprising the step of administering a a COX-2 inhibitor, a non-seiective anti-inflammatory agent, acetaminophen, or a steroid.

15. The method of Claim 14 wherein said COX-2 inhibitor is Celebrex, said nonselective anti-inflammatory agent is ibuprofen or naproxen, and said steroid is prednisolone, or budesonide.

16. A method for treating inflammatory pain comprising the step of administering to an animal in need thereof a therapeutically effective amount of a CB-1 antagonist.

17. The method of Claim 16 further comprising the step of administering a a COX-2 inhibitor, a non-selective anti-inflammatory agent, acetaminophen, or a steroid.

18. The method of Claim 14 wherein said COX-2 inhibitor is Celebrex, said nonselective anti-inflammatory agent is ibuprofen or naproxen, and said steroid is prednisolone, or budesonide.

19. The method of any one of the preceding Claims wherein said CB-1 antagonist is selected from the group consisting of rimonabant;

Λ/-(piperidin-1-yl)-1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-1 H-pyrazole-3- carboxamide; δ^-bromophenyO-i^^-dichloro-phenyO^-ethyl-Λ/^i-piperidinylJ-IH-pyrazole-S- carboxamide;

Λ/-(piperidin-1-yl)-4,5-diphenyl-1-methylimidazole-2-carboxamide;

/V-(piperidin-1-yl)-4-(2,4-dichlorophenyl)-5-(4-chlorophenyl)-1-methylimidazole-2- carboxamide;

Λ/-(piperidin-1-yl)-4,5-di-(4-methylphenyl)-1-methylimidazole-2-carboxamide;

Λ/-cyclohexyl-4,5-di-(4-methylphenyl)-1-methylimidazole-2-carboxamide;

/V-(cyclohexyl)-4-(2,4-dichlorophenyl)-5-(4-chlorophenyl)-1-methylimidazole-2- carboxamide; Λ/^phenyO^^^-dichlorophenylJ-δ^-chlorophenyO-i-methylimidazole^-carboxamide; hydrochloride, mesylate or besylate salt of 1-[9-(4-chloro-phenyl)-8-(2-chloro-phenyl)- 9H-purin-6-yl]-4-ethylamino-piperidine-4-carboxylic acid amide;

ethylamino-azetidine-3-carboxylic acid amide; 1-[7-(2-chloro-phenyl)-8-(4-chloro-phenyl)-2-methyl-pyrazolo[1 ,5-a][1 ,3,5]triazin-4-yl]-3- methylamino-azetidine-3-carboxylic acid amide;

S^-chloro-phenyl^^-chloro-phenylJ-δ^^-difluoro-propylJ-Σ^.δ.δ-tetrahydro- pyrazolo[3,4-c]pyridin-7-one;

2-(2-chloro-phenyl)-3-(4-ethyl-phenyl)-5-(2,2,2-trifluoro-ethyl)-4,5-dihydro-2H- pyrrolo[3,4-c]pyrazol-6-one;

2-(2-chloro-phenyl)-3-(4-isopropyl-phenyl)-5-(2,2,2-trifluoro-ethyl)-4,5-dihydro-2H- pyrrolo[3,4-c]pyrazol-6-one;

S^-chloro-phenylJ-Σ^-chloro-phenylJ-T^^-difluoro-propylJ-δJ-dihydro^H.δH^-oxa- 1 ,2,7-triaza-azulen-8-one; 2-(2-chloro-phenyl)-6-(2,2,2-trifluoro-ethyl)-3-(4-trifluoromethyl-phenyl)-2,6-dihydro- pyrazolo[4,3-d]pyrimidin-7-one;

(SJ^-chloro-N-lfS^-chloro-phenyO^-phenyl^.δ-dihydro-pyrazol-i-ylJ-methylamino- methylene}-benzenesulfonamide;

(S)-N-{[3-(4-chloro-phenyl)-4-phenyl-4,5-dihydro-pyrazol-1-yl]-methylamino-methylene}- 4-trifluoromethyl-benzenesulfonamide;

N-piperidino-δ^-bromophenyO-i^^-dichlorophenyO^-ethylpyrazole-S-carboxamide; 1-[bis-(4-chloro-phenyl)-methyl]-3-[(3,5-difluoro-phenyl)-methanesulfoπyl-methylene]- azetidine;

2-(5-(trifluoromethyl)pyridin-2-yloxy)-N-(4-(4-chlorophenyl)-3-(3-cyanophenyl)butan-2- yl)-2-methylpropanamide;

4-{[6-methoxy-2-(4-methoxyphenyl)-1-benzofuran-3-yl]carbonyl}benzonitrile; 1-[2-(2,4-dichlorophenyl)-2-(4-fluorophenyl)-benzo[1 ,3]dioxole-δ-sulfonyl]-piperidine; and S-amino-δ^-chlorophenyO-δ^^-dichlorophenyO-furop.S-bJpyridiπ-Σ-yll-phenyl- methanone.