HK1259909A1 - Treatment of muscular disorders with combinations of rxr agonists and thyroid hormones - Google Patents

Description

Treatment of muscle disorders with a combination of RXR agonists and thyroid hormones

RELATED APPLICATIONS

This application claims priority to U.S. provisional patent application No. 62/306472 filed on 10/3/2016. The entire contents of this application are incorporated herein by reference.

Technical Field

The present disclosure relates to methods of treating muscle disorders using a Retinoid X Receptor (RXR) agonist in combination with a thyroid hormone.

Background

Compounds having retinoid-like biological activity are well known in the art and are described in a number of U.S. patents, including, but not limited to, U.S. patent application 5466861; 5675033 and 5917082, all of which are incorporated herein by reference. Preclinical studies of rexinoids (agonists of RXRs) have shown that selective activation of Retinoid X Receptors (RXRs) that modulate functions associated with differentiation, inhibition of cell growth, apoptosis, and metastasis can be used to treat a variety of diseases associated with RXRs.

Attempts to treat muscle disorders have met with limited success. This is due in part to the etiology of muscle disease being a complex response based in part on a variety of factors, including, but not limited to, an individual's genetic makeup, immune dysfunction, enzyme deficiency, endocrine dysfunction, metabolic abnormalities, gender or hormonal status, bacterial or viral infection, exposure to metal or chemical toxins, vaccination or immunization, stress, trauma, and/or nutritional deficiencies. Thus, there is a great need for compounds, compositions and methods that can treat or alleviate symptoms associated with muscle disorders.

There are two major classes of receptors that mediate the effects of vitamin a derivatives in mammals (and other organisms), Retinoic Acid Receptors (RARs) and Retinoid X Receptors (RXRs), three subtypes in each class, RAR α, RAR β and RAR γ for the RAR family, RXR α, RXR β and RXR γ for the RXR family.

PPAR protein subtypes include PPAR α, PPAR β/δ, and PPAR γ, RXR forms heterodimers with each subtype PPAR α regulates lipid metabolism and is well expressed in the liver, heart, muscle, and kidney, PPAR γ is predominantly expressed in macrophages and adipocytes, and regulates adipocyte differentiation, lipid homeostasis, and inflammation PPAR β/δ regulates energy balance and lipid and glucose metabolism, and is a potential drug target for the metabolic syndrome.

While RAR agonists such as RA have been used to treat a variety of diseases, including metabolic diseases and cancer, their use in clinical practice has been limited due to undesirable side effects and counter-therapeutic inflammatory effects. Thus, there is a need for compounds and compositions that promote the maintenance of muscle function, but do not have any pro-inflammatory activity associated with RAR pan agonists such as RA, as well as other undesirable side effects. These compounds have considerable therapeutic value as immunomodulators.

Disclosure of Invention

Activation of Retinoic Acid Receptors (RARs) by non-selective retinoic acid X receptor (RXR) agonists decreases the efficacy of RXR agonists in muscle disorders. Thus, the efficacy of RXR agonists in muscle disorders can be improved by administering doses of RXR agonists that activate RXR but minimally or not at all activate RAR. It has now been proposed that RXR agonists at doses that only specifically activate RXRs may produce optimal anti-muscle disease activity when administered in combination with thyroid hormones. Based on this proposal, a novel method of treating a patient suffering from a muscle disease is disclosed herein.

Accordingly, disclosed herein is a method of treating a muscle disorder comprising administering to an individual in need thereof a therapeutically effective amount of a RXR agonist and one or more thyroid hormones, wherein the administration of the RXR agonist and thyroid hormones is more effective in treating the muscle disorder in the individual than treatment with the RXR agonist or thyroid hormones alone.

In one embodiment, the RXR agonist has the structure shown in formula II

Wherein R is H or lower alkyl of 1-6 carbons. In some embodiments, the RXR agonist is a selective RXR agonist comprising 3, 7-dimethyl-6 (S),7(S) -methanone, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydronaphthalen-7-yl ]2(E),4(E) heptadienoic acid. In other embodiments, the RXR agonist is 3, 7-dimethyl-6 (S),7(S) -methanone, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydronaphthalen-7-yl ]2(E),4(E) heptadienoic acid ethyl ester. In other embodiments, the RXR agonist is bexarotene. In other embodiments, the RXR agonist is LG 268.

In some embodiments, the thyroid hormone is thyroxine.

In some embodiments, the therapeutically effective amount of the RXR agonist is from about 0.001 mg/day to about 1000 mg/day. In certain embodiments, a therapeutically effective amount of an ester of an RXR agonist is from about 0.001 mg/day to about 1000 mg/day. In other embodiments, the therapeutically effective amount of the RXR agonist is from about 10 mg/day to about 1000 mg/day, or from 1 mg/day to 20 mg/day. In other embodiments, a therapeutically effective amount of thyroxine is from about 12.5 μ g/day to about 250 μ g/day.

In some embodiments, the RXR agonist is administered by nasal administration. In other embodiments, the RXR agonist and the thyroxine are both administered by nasal administration. In other embodiments, the RXR agonist is administered orally. In other embodiments, the thyroxine is administered orally. In still other embodiments, the thyroxine is administered subcutaneously.

In certain embodiments, the RXR agonist and the thyroxine are administered substantially simultaneously. In other embodiments, the RXR agonist and the thyroxine are administered at different times.

In some embodiments, the method treats a condition selected from the group consisting of acid maltase deficiency, dystonia, atrophy, ataxia, Becker Muscular Dystrophy (BMD), myocardial ischemia, myocardial infarction, cardiomyopathy, carnitine deficiency, carnitine palmitoyl transferase deficiency, central axial vacancy disease (CCD), central nuclear (myotube) myopathy, cerebral palsy, fascial space syndrome, channelopathy, Congenital Muscular Dystrophy (CMD), corticosteroid myopathy, spasticity, dermatomyositis, distal muscular dystrophy, Duchenne Muscular Dystrophy (DMD), dystrophic diseases (dystrophinopathies), Emery-Dreifuss muscular dystrophy (EDMD), scapular muscular dystrophy (FSHD), fibromyalgia, fibrositis, Limb Girdle Muscular Dystrophy (LGMD), mcarder's syndrome, muscular dystrophy, muscle fatigue, myasthenia gravis, myocardial ischemia, myocardial infarction, and joint strain, Myofascial pain syndrome, myopathy, myotonia, myotonic dystrophy type 1, myotonic dystrophy type 2, linear myopathy, oculopharyngeal muscular dystrophy (OCM), myoglobinuria, congenital paramyotonia (Eulenberg disease), polymyositis, rhabdomyolysis, sarcoidosis (sarcoglobinopathies) or muscle spasm.

In some embodiments, the myopathy is dermatomyositis, inclusion body myositis, or polymyositis.

In certain embodiments, the muscle disease is caused by cancer, HIV/AIDS, COPD, chronic use of steroids, fibromyalgia, or skeletal muscle myopathy.

In other embodiments, the combination of rexinoids and thyroid hormones is beneficial by achieving myocardial protection or regeneration in vivo or in vitro to facilitate subsequent implantation of myocytes into damaged myocardium.

Also provided herein is a method of treating a muscle disorder, the method comprising administering to a subject in need thereof a therapeutically effective amount of 3, 7-dimethyl-6 (S),7(S) -methanone, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydronaphthalen-7-yl ]2(E),4(E) heptadienoic acid, and thyroxine; also, the co-administration can more effectively reduce the severity of a muscle disease in an individual than RXR agonist or thyroxine alone, by slowing or stopping progression, or inducing or accelerating repair or regeneration of the affected muscle.

Drawings

Figure 1 shows activation of RXR agonists transcribed from RXR α β γ, RAR α β and RAR γ using a transactivation assay.

FIGS. 2A-D show that IRX4204 selectively activates RXR-Nurr1 heterodimers IRX4204(194204, formula III) was assayed for transactivation of the farnesoid X receptor FXR (FIG. 2A), the liver X receptors LXR α and LXR β (FIG. 2B), the peroxisome proliferator-activated receptor PPAR γ (FIG. 2C), and the Nurr1 receptor with or without RXR (FIG. 2D).

FIG. 3 shows the percentage of green fluorescent protein (EGFP) -positive oligodendrocytes following incubation of oligodendrocyte precursor cells derived from embryonic mouse brain marrow with IRX4204 and thyroid hormone.

Figure 4 depicts the change in paw placement behavior in mice with 6-OHDA induced parkinson's disease after treatment with the compounds and compositions described herein (p <0.05 versus vehicle, using one-way ANOVA followed by Dunnett's test).

FIG. 5 depicts the percentage and fold change of EGFP + oligodendrocytes after treatment of oligodendrocytes with IRX4204, thyroid hormone and vitamin D (.: P <0.05, student's t-test against DMSO control; error bars, SD).

FIGS. 6A-C depict the percent change in EGFP + oligodendrocytes following IRX4204 and thyroid hormone treatment of oligodendrocytes (FIG. 6A: 10nM IRX 4204; FIG. 6B: 1nM IRX 4204; FIG. 6C: 0.1nM IRX 4204). P < 0.0001; p < 0.01.

Figure 7 depicts terminal circulating serum T4 levels in animals receiving vector, IRX4204 or IRX4204 and T4 (. P <0.005 control vector and young (naive) control).

Figure 8 depicts the amount of SMI32 positive ovoids (ovaids) in the callus of animals receiving vector, IRX4204 or IRX4204 and T46 weeks (. P <0.05, vs Veh + Veh control).

FIGS. 9A-C depict the amount of myelination of callus after in vivo treatment with the compositions described herein, and the data was divided into potential responders and non-responders (multiple comparisons of one-way ANOVA to Tukey, P<0.05**P<0.01，****P<0.001). Fig. 9A depicts myelinated axons per CC unit; FIG. 9B depicts the density of myelinated axons (per 10000 μm)²) (ii) a FIG. 9C depicts the density of SM132+ ovoids (per 250000 μm)²)。

Detailed Description

Preclinical studies using rexinoids have shown that selective activation of Retinoid X Receptors (RXRs) that modulate functions associated with differentiation, inhibition of cell growth, apoptosis, and metastasis are useful in the treatment of a variety of diseases associated with RXRs.

RAR means one or more of RAR α, β, and γ. RXR generally means one or more of RXR α, β, and γ. RAR biomarkers are unique biologically, biochemically, or biologically derived indicators that indicate RAR activity in a patient.

The RAR activation threshold refers to one or more of (1) CYP26 levels, which are 25% higher than baseline, and (2) CRBPI levels, which are 25% higher than baseline. RARs often form heterodimers with RXRs, and these RAR/RXR heterodimers bind to specific response elements in the promoter region of target genes. Binding of RAR agonists to the RAR receptors of the heterodimer results in activation of transcription of the target gene, thereby leading to retinoid effects. On the other hand, RXR agonists do not activate the RAR/RXR heterodimer. RXR heterodimer complexes such as RAR/RXR can be referred to as unlicensed RXR heterodimers because activation of transcription by ligand binding occurs only on non-RXR proteins (e.g., RARs); transcriptional activation does not occur due to ligand binding on RXRs. RXRs also interact with nuclear receptors other than RARs, and RXR agonists can elicit some of their biological effects by binding to this RXR/receptor complex.

These RXR/receptor complexes may be referred to as permissive RXR heterodimers because activation of transcription by ligand binding may occur at the RXR, the other receptor, or both receptors. Examples of permissive RXR heterodimers include, but are not limited to, peroxisome proliferator activated receptors/RXRs (PPAR/RXRs), farnesyl X receptors/RXRs (FXR/RXRs), nuclear receptor-related-1 proteins (Nurr 1/RXRs), and liver X receptors/RXRs (LXR/RXRs). Alternatively, RXRs may form RXR/RXR homodimers, which may be activated by RXR agonists causing rexinoid effects. In addition, RXRs interact with proteins other than nuclear receptors, and ligand binding to RXRs within these protein complexes can also cause rexinoid effects. Due to these differences in mechanism of action, RXR agonists and RAR agonists elicit different biological outcomes, and even where they mediate similar biological effects, they do so by different mechanisms. In addition, undesirable side effects of retinoids, such as pro-inflammatory responses or mucocutaneous toxicity, are mediated by activation of one or more RAR receptor subtypes. In other words, biological effects mediated by the RXR pathway do not induce pro-inflammatory responses and therefore do not lead to undesirable side effects.

Thus, aspects of the present specification provide, in part, RXR agonists as used herein, the term "RXR agonist" is synonymous with "RXR selective agonist" and refers to a compound that selectively binds one or more RXR receptors, such as RXR α, RXR β, or RXR γ, in a manner that triggers gene transcription by a RXR responsive element.

In one embodiment, the selective RXR agonist does not activate to any appreciable extent the permissive heterodimers PPAR/RXR, FXR/RXR and LXR/RXR. In another embodiment, an RXR agonist activates the permissive heterodimer Nurr 1/RXR. An example of such a selective RXR agonist is 3, 7-dimethyl-6 (S),7(S) -methano, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydronaphthalen-7-yl ]2(E),4(E) heptadienoic acid (IRX4204) disclosed herein, the structure of which is shown in formula III. In other aspects of this embodiment, the RXR agonist activates the permissive heterodimers PPAR/RXR, FXR/RXR or LXR/RXR at 1% or less, 2% or less, 3% or less, 4% or less, 5% or less, 6% or less, 7% or less, 8% or less, 9% or less, 10% or less relative to the ability of an agonist to a non-RXR receptor to activate the same permissive heterodimers. Examples of RXR agonists that activate one or more of PPAR/RXR, FXR/RXR, or LXR/RXR include LGD1069 (bexarotene) and LGD 268.

Like some other RXR ligands, IRX4204 does not activate unlicensed heterodimers, such as RAR/RXR. However, IRX4204 is unique in that it can specifically activate Nurr1/RXR heterodimers and does not activate other permissive RXR heterodimers such as PPAR/RXR, FXR/RXR, and LXR/RXR. Other RXR ligands typically activate these permissive RXR heterodimers. Thus, not all RXR ligands can belong to one class. IRX4204 belongs to a unique class of RXR ligands that selectively activate one of the RXR homodimers as well as permissive RXR heterodimers, i.e., Nurr1/RXR heterodimers.

Specific binding is the ability of a RXR agonist to distinguish between a RXR receptor and a receptor that does not contain its binding site (e.g., a RAR receptor).

More specifically, disclosed herein are esters of RXR agonists. May be an ester derived from a carboxylic acid of C1, or may be derived from a carboxylic acid functional group on another part of the molecule (e.g. on the phenyl ring). Although not limiting, the esters may be alkyl, aryl, or heteroaryl esters. The term alkyl has the meaning commonly understood by those skilled in the art and refers to a straight chain, branched chain or cyclic alkyl moiety. C_1-6Alkyl esters are particularly useful wherein the alkyl portion of the ester has 1 to 6 carbon atoms and include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl isomers, hexyl isomers, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, combinations having 1-6 carbon atoms, and the like.

Accordingly, disclosed herein are RXR agonists or esters thereof having the structure of formula I:

wherein R is⁴Is a lower alkyl group of 1 to 6 carbons; b is-COOR⁸Wherein R is⁸Is a lower alkyl group of 1 to 6 carbons, and the configuration of the cyclopropane ring is cisThe configuration of the double bond in the pentadienoic acid or ester chain attached to the cyclopropane ring of formula (la) is trans in each double bond.

In one exemplary embodiment, the ester of the RXR agonist is a compound having the structure of formula II:

wherein R is a lower alkyl group of 1 to 6 carbons.

In another exemplary embodiment, the RXR agonist may be a selective RXR agonist comprising 3, 7-dimethyl-6 (S),7(S) -methanone, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydronaphthalen-7-yl ]2(E),4(E) heptadienoic acid (IRX4204), or esters thereof, and having the structure of formula III:

in certain embodiments, the RXR agonist may be bexarotene (r) ((r))4- [1- (3,5,5,8, 8-pentamethyl-6, 7-dihydronaphthalen-2-yl) ethenyl]Benzoic acid, LGD1069, Mylan Pharmaceuticals) or an ester thereof, having the structure of formula IV:

in other embodiments, the RXR agonist can be LG268(LG100268, LGD268, 2- [1- (3,5,5,8, 8-pentamethyl-5, 6,7, 8-tetrahydro-2-naphthyl) cyclopropyl ] pyridine-5-carboxylic acid), or an ester thereof, having the structure of formula V:

pharmaceutically acceptable salts of RXR agonists or esters thereof may also be used in the disclosed methods. The compounds disclosed herein have sufficient acidic groups, sufficient basic groups, or both functional groups and thus can react with any of a variety of organic or inorganic bases, inorganic and organic acids to form salts.

Administration of RXR agonists or esters thereof can result in suppression of serum thyroid hormones and may lead to hypothyroidism and related disorders. In some embodiments, the thyroid hormone may be used in combination with a RXR agonist or ester thereof. As used herein, the term "thyroid hormone" refers to thyroxine and triiodothyronine. Thyroxine (thyroid hormone T)₄Levothyroxine sodium) is a tyrosine-based hormone produced by the thyroid gland and is primarily responsible for regulating metabolism. Thyroxine is triiodothyronine (T)₃) The source of hormone of (1). RXR agonists are known to inhibit thyroid function. However, supplementation of RXR agonist therapy with thyroid hormones has not been therapeutically useful to enhance the effect of RXR agonists.

Aspects of the present specification provide, in part, compositions comprising RXR agonists, or esters or other derivatives thereof, and thyroid hormones. Examples of RXR agonists are IRX4204, bexarotene and LG 268. Examples of esters of RXR agonists are IRX4204 ethyl ester (IRX4204EE), esters of bexarotene and esters of LG 268.

Aspects of the methods of the present disclosure, in part, include the treatment of mammals. Mammals include humans, which may be patients. Other aspects of the disclosure provide, in part, an individual. Individuals include mammals and humans, and humans may be patients.

The RXR agonists or esters thereof, or compositions comprising RXR agonists or esters thereof, or combinations of RXR agonists or esters thereof with thyroid hormones (e.g., thyroxine) as disclosed herein are typically administered to an individual as a pharmaceutical composition.

Pharmaceutical compositions may be prepared by combining a therapeutically effective amount of at least one RXR agonist (as active ingredient) with conventional acceptable pharmaceutical excipients, and by preparing unit dosage forms suitable for therapeutic use. As used herein, the term "pharmaceutical composition" refers to a therapeutically effective concentration of an active compound, such as any of the compounds disclosed herein. Preferably, the pharmaceutical composition does not produce adverse, allergic, or other adverse or undesirable reactions when administered to an individual. The pharmaceutical compositions disclosed herein are useful for medical and veterinary applications. The pharmaceutical composition may be administered to an individual alone or in combination with other supplementary active compounds, agents, drugs or hormones. The pharmaceutical compositions may be prepared using any of a variety of methods, including but not limited to, conventional mixing, dissolving, granulating, dragee-making, grinding, emulsifying, encapsulating, entrapping, and lyophilizing. The pharmaceutical compositions may take any of a variety of forms, including, but not limited to, sterile solutions, suspensions, emulsions, lyophilizates, tablets, pills, pellets, capsules, powders, syrups, elixirs, or any other dosage form suitable for administration.

The pharmaceutical compositions produced using the methods disclosed herein can be liquid, semi-solid, or solid formulations. The formulations disclosed herein can be prepared in a manner to form a single phase (e.g., without limitation, an oil or a solid). Alternatively, the formulations disclosed herein can be prepared in a manner to form two phases (e.g., an emulsion). The pharmaceutical compositions disclosed herein for such administration can be prepared according to any method known in the art for preparing pharmaceutical compositions.

Liquid formulations suitable for parenteral injection or nasal spray may comprise physiologically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions as well as sterile powders for reconstitution into sterile injectable solutions or dispersions. Formulations suitable for nasal administration may comprise physiologically acceptable sterile aqueous or nonaqueous solutions, dispersions, suspensions or emulsions. Examples of suitable aqueous and non-aqueous carriers (carriers), diluents, solvents or vehicles (vehicles) include, but are not limited to, water, ethanol, polyols (propylene glycol, polyethylene glycol (PEG), glycerol, and the like), suitable mixtures thereof, vegetable oils (such as olive oil or peanut oil) and injectable organic esters such as ethyl oleate. For example, proper fluidity can 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 dispersion and by the use of surfactants.

Aqueous suspensions may include pharmaceutically acceptable excipients such as, but not limited to, a) suspending agents, for example, sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; b) dispersing or wetting agents such as naturally occurring phosphatides or lecithins, or condensation products of an alkylene oxide with fatty acids, for example but not limited to polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example but not limited to heptadecaalkyloxyethanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example but not limited to polyoxyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, ethyl-or n-propyl-p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as, but not limited to, sucrose, saccharin or sodium cyclamate or calcium.

Pharmaceutical formulations adapted for administration by inhalation include fine particle dusts or mists, which may be generated by means of various types of metered, dose pressurised aerosols, nebulizers or insufflators.

Semisolid formulations suitable for topical administration include, but are not limited to, ointments, creams, salves, and gels. In such solid formulations, the active compound may be mixed with at least one inert conventional excipient (or carrier), such as, but not limited to, oils and/or polyethylene glycols.

Solid formulations suitable for oral administration include capsules, tablets, pills, powders and granules. In such solid formulations, the active compound may be mixed with at least one inert conventional excipient (or carrier), such as, but not limited to, sodium citrate or dicalcium phosphate or (a) fillers or extenders, such as, but not limited to, starches, lactose, sucrose, glucose, mannitol, and silicic acid, (b) binders, such as, but not limited to, carboxymethylcellulose, alginates, gelatin, polyvinylpyrrolidone, sucrose, and acacia, (c) humectants, such as, but not limited to, glycerol, (d) disintegrating agents, such as, but not limited to, agar, calcium carbonate, potato or tapioca starch, alginic acid, certain complex silicates, and sodium carbonate, (e) solution retarders, such as, but not limited to, paraffin, (f) absorption enhancers, such as, but not limited to, quaternary ammonium compounds, (g) wetting agents, such as, but not limited to, cetyl alcohol, and glyceryl monostearate, (h) adsorbents such as, but not limited to, kaolin and bentonite, and (i) lubricants such as, but not limited to, talc, calcium stearate, magnesium stearate, solid polyethylene glycols, sodium lauryl sulfate or mixtures thereof. In the case of capsules, tablets and pills, the dosage forms may also comprise buffering agents.

In liquid or semisolid formulations, the concentration of the RXR agonist is typically between 50mg/mL to 1000 mg/mL. In some aspects of this embodiment, a therapeutically effective amount of a therapeutic compound disclosed herein can be from about 50mg/mL to about 100mg/mL, about 50mg/mL to about 200mg/mL, about 50mg/mL to about 300mg/mL, about 50mg/mL to about 400mg/mL, about 50mg/mL to about 500mg/mL, about 50mg/mL to about 600mg/mL, about 50mg/mL to about 700mg/mL, about 50mg/mL to about 800mg/mL, about 50mg/mL to about 900mg/mL, about 50mg/mL to about 1000mg/mL, about 100mg/mL to about 200mg/mL, about 100mg/mL to about 300mg/mL, about 100mg/mL to about 400mg/mL, about 100mg/mL to about 500mg/mL, or, About 100mg/mL to about 600mg/mL, about 100mg/mL to about 700mg/mL, about 100mg/mL to about 800mg/mL, about 100mg/mL to about 900mg/mL, about 100mg/mL to about 1000mg/mL, about 200mg/mL to about 300mg/mL, about 200mg/mL to about 400mg/mL, about 200mg/mL to about 500mg/mL, about 200mg/mL to about 600mg/mL, about 200mg/mL to about 700mg/mL, about 200mg/mL to about 800mg/mL, about 200mg/mL to about 900mg/mL, about 200mg/mL to about 1000mg/mL, about 300mg/mL to about 400mg/mL, about 300mg/mL to about 500mg/mL, about 300mg/mL to about 600mg/mL, about 300mg/mL to about 700mg/mL, about, About 300mg/mL to about 800mg/mL, about 300mg/mL to about 900mg/mL, about 300mg/mL to about 1, 000mg/mL, about 400mg/mL to about 500mg/mL, about 400mg/mL to about 600mg/mL, about 400mg/mL to about 700mg/mL, about 400mg/mL to about 800mg/mL, about 400mg/mL to about 900mg/mL, about 400mg/mL to about 1000mg/mL, about 500mg/mL to about 600mg/mL, about 500mg/mL to about 700mg/mL, about 500mg/mL to about 800mg/mL, about 500mg/mL to about 900mg/mL, about 500mg/mL to about 1000mg/mL, about 600mg/mL to about 700mg/mL, about 600mg/mL to about 800mg/mL, about 600mg/mL to about 900mg/mL, about 600mg/mL to about 1000mg/mL, or any other range constrained by these values.

In semi-solid and solid formulations, the amount of RXR agonist can be between about 0.01% to about 45% by mass. In some aspects of this embodiment, the amount of a therapeutic compound disclosed herein can be 0.1% to about 45% by mass, about 0.1% to about 40% by mass, about 0.1% to about 35% by mass, about 0.1% to about 30% by mass, about 0.1% to about 25% by mass, about 0.1% to about 20% by mass, about 0.1% to about 15% by mass, about 0.1% to about 10% by mass, about 0.1% to about 5% by mass, about 1% to about 45% by mass, about 1% to about 40% by mass, about 1% to about 35% by mass, about 1% to about 30% by mass, about 1% to about 25% by mass, about 1% to about 20% by mass, about 1% to about 15% by mass, about 1% to about 10% by mass, about 1% to about 5% by mass, about 5% to about 40% by mass, about 40% by mass, About 5% to about 35% by mass, about 5% to about 30% by mass, about 5% to about 25% by mass, about 5% to about 20% by mass, about 5% to about 15% by mass, about 5% to about 10% by mass, about 10% to about 45% by mass, about 10% to about 40% by mass, about 10% to about 35% by mass, about 10% to about 30% by mass, about 10% to about 25% by mass, about 10% to about 20% by mass, about 10% to about 15% by mass, about 15% to about 45% by mass, about 15% to about 40% by mass, about 15% to about 35% by mass, about 15% to about 30% by mass, about 15% to about 25% by mass, about 15% to about 20% by mass, about 20% to about 45% by mass, about 20% to about 40% by mass, about 20% to about 35% by mass, about 10% to about 15% by mass, about 15% to about 45% by mass, About 20% to about 30% by mass, about 20% to about 25% by mass, about 25% to about 45% by mass, about 25% to about 40% by mass, about 25% to about 35% by mass, about 25% to about 30% by mass, or any other range bounded by these values.

The pharmaceutical compositions disclosed herein may optionally include a pharmaceutically acceptable carrier that facilitates processing of the active compound into a pharmaceutically acceptable composition. As used herein, the term "pharmaceutically acceptable" refers to those compounds, materials, compositions, and/or dosage forms which are, within the scope of sound medical judgment, suitable for contact with the tissues of human beings and animals without excessive toxicity, irritation, allergic response, or other problem complication commensurate with a reasonable benefit/risk ratio. As used herein, the term "pharmacologically acceptable carrier" is synonymous with "pharmacological carrier" and refers to any carrier that is substantially free of long-term or permanent deleterious effects upon administration, and includes terms such as "pharmacologically acceptable carrier, stabilizer, diluent, additive, adjuvant or excipient". Such carriers are typically mixed with the active compound or allow dilution or encapsulation of the active compound and may be solid, semi-solid or liquid agents. It will be appreciated that the active compound may be soluble or may be delivered as a suspension in a desired carrier or diluent.

Any of a variety of pharmaceutically acceptable carriers can be used, including, but not limited to, aqueous media such as water, saline, glycine, hyaluronic acid, and the like; solid carriers such as starch, magnesium stearate, mannitol, sodium saccharin, talcum, cellulose, glucose, sucrose, lactose, trehalose, magnesium carbonate, and the like; a solvent; a dispersion medium; coating; antibacterial and antifungal agents; isotonic and absorption delaying agents; or any other inactive ingredient. Can be administered according to the mode of administrationA pharmacologically acceptable carrier is selected. Unless a pharmacologically acceptable carrier is incompatible with the active compound, its use in pharmaceutically acceptable compositions is contemplated. Non-limiting examples of specific uses of such Pharmaceutical carriers can be found in Pharmaceutical Dosage Forms and drug Delivery Systems (Howard C.Ansel et al, eds., Lippincott Williams)&WilkinsPublishers,7^thed.1999)；Remington:The Science and Practice of Pharmacy(AlfonsoR.Gennaro ed.,Lippincott,Williams&Wilkins,20^thed.2000)；Goodman&Gilman's ThePharmacological Basis of Therapeutics(Joel G.Hardman et al.,eds.,McGraw-HillProfessional,10^thed.2001); and Handbook of Pharmaceutical Excipients (Raymond. Rowe et al, APhA Publications,4^thedition 2003). Such protocols are conventional and any modifications are within the skill of the art and the teachings herein.

The pharmaceutical compositions disclosed herein may optionally include, but are not limited to, other pharmaceutically acceptable components (or pharmaceutical ingredients) including, but not limited to, buffers, preservatives, tonicity adjusting agents, salts, antioxidants, tonicity adjusting agents, physiological substances, pharmacological substances, bulking agents, emulsifiers, wetting agents, sweeteners or flavoring agents and the like. Various buffers and means for adjusting the pH may be used in the preparation of the pharmaceutical compositions disclosed herein, provided that the resulting formulation is pharmaceutically acceptable. These buffers include, but are not limited to, acetate buffer, borate buffer, citrate buffer, phosphate buffer, neutral buffered saline, and phosphate buffered saline. It is understood that acids or bases can be used to adjust the pH of the composition as desired.

Pharmaceutically acceptable antioxidants include, but are not limited to, sodium metabisulfite, sodium thiosulfate, acetylcysteine, butylated hydroxyanisole, and butylated hydroxytoluene. Useful preservatives may include, but are not limited to, benzalkonium chloride, chlorobutanol, thimerosal, phenylmercuric acetate, phenylmercuric nitrate, stabilized oxychloro compounds, sodium chlorite and chelating agents, DTPA or DTPA-bisamide, calcium DTPA and CaNaDTPA-bisamide. Tonicity adjusting agents that may be used in the pharmaceutical composition may include, but are not limited to, salts such as sodium chloride, potassium chloride, mannitol, or glycerol and other pharmaceutically acceptable tonicity adjusting agents. The pharmaceutical compositions may be provided in the form of a salt, and may be formed with a number of acids, including but not limited to hydrochloric acid, sulfuric acid, acetic acid, lactic acid, tartaric acid, malic acid, succinic acid, and the like. Salts are more readily soluble in water or other protic solvents than the corresponding free base form. It is to be understood that these and other materials known in the pharmacological arts can be included in the useful pharmaceutical compositions herein.

The compounds disclosed herein, e.g., combinations of RXR agonists and thyroid hormones, can also be incorporated into drug delivery platforms in order to achieve a controlled release profile of the compound over time. Such drug delivery platforms can comprise the combinations disclosed herein dispersed within a polymeric matrix, which is typically a biodegradable, bioerodible, and/or bioresorbable polymeric matrix. As used herein, the term "polymer" refers to synthetic homopolymers or copolymers, naturally occurring homopolymers or copolymers having a linear, branched, or star structure, and man-made modifications or derivatives thereof. The copolymers may be arranged in any form, such as random, block, segmented, tapered, graft, or triblock. The polymer is typically a condensation polymer. The polymer may be further modified to enhance its mechanical or degradation properties by introducing cross-linkers or by altering the hydrophobicity of the pendant groups. If crosslinked, the polymer is typically less than 5% crosslinked, typically less than 1% crosslinked.

Suitable polymers may include, but are not limited to, alginates, aliphatic polyesters, polyalkylene oxalates, polyamides, polyesteramides, polyanhydrides, polycarbonates, polyesters, polyethylene glycols, polyhydroxyaliphatic carboxylic acids, polyorthoesters, polyoxaesters, polypeptides, polyphosphazenes, polysaccharides, and polyurethanes. The polymer typically comprises at least about 10% (w/w), at least about 20% (w/w), at least about 30% (w/w), at least about 40% (w/w), at least about 50% (w/w), at least about 60% (w/w), at least about 70% (w/w), at least about 80% (w/w), or at least about 90% (w/w) of the drug delivery platform. Examples of biodegradable, bioerodible, and/or bioresorbable polymers and methods for making drug delivery platforms are described in U.S. patent nos. 4756911; 5378475, respectively; 7048946, respectively; and U.S. patent publication No. 2005/0181017; 2005/0244464, respectively; 2011/0008437, each of which is incorporated by reference as they disclose information relating to drug delivery.

In aspects of this embodiment, the polymer comprising the matrix may be a polypeptide, such as, but not limited to, silk fibroin, keratin, or collagen. In other aspects of this embodiment, the polymer comprising the matrix may be a polysaccharide, such as, but not limited to, cellulose, agarose, elastin, chitosan, chitin or mucopolysaccharides such as chondroitin sulfate, dermatan sulfate, keratan sulfate or hyaluronic acid. In other aspects of this embodiment, the polymer comprising the matrix can be a polyester, such as D-lactic acid, L-lactic acid, racemic lactic acid, glycolic acid, caprolactone, and combinations thereof.

One of ordinary skill in the art understands that the selection of a suitable polymer for forming a suitable disclosed drug delivery platform depends on a variety of factors. Factors of relevance in selecting an appropriate polymer include, but are not limited to, compatibility of the polymer with the drug, desired drug release kinetics, desired biodegradation kinetics at the implantation site platform, desired bioerodible kinetics at the implantation site platform, desired bioabsorbability kinetics at the implantation site platform, in vivo mechanical properties of the platform, processing temperature, biocompatibility of the platform, and patient tolerance. Other relevant factors that determine to some extent the in vitro and in vivo behavior of polymers include chemical composition, spatial distribution of components, molecular weight and crystallinity of the polymer.

The drug delivery platforms may include sustained release drug delivery platforms and extended release drug delivery platforms. The term "sustained release" as used herein refers to release of a compound disclosed herein over a period of about 7 days or more. The term "extended release" as used herein refers to release of a compound disclosed herein in less than about 7 days.

In aspects of this embodiment, the sustained release drug delivery platform can release the RXR agonist disclosed herein, or a combination of the RXR agonist and a thyroid hormone, at substantially first order release kinetics over a time period of about 7 days post-administration, about 15 days post-administration, about 30 days post-administration, about 45 days post-administration, about 60 days post-administration, about 75 days post-administration, or about 90 days post-administration. In other aspects of this embodiment, the sustained release drug delivery platform releases a compound disclosed herein with substantially first order release kinetics over a period of at least 7 days post-administration, at least 15 days post-administration, at least 30 days post-administration, at least 45 days post-administration, at least 60 days post-administration, at least 75 days post-administration, or at least 90 days post-administration.

In aspects of this embodiment, the drug delivery platform can release the RXR agonist disclosed herein, or a combination of the RXR agonist and a thyroid hormone, at substantially first order release kinetics over a period of about 1 day post-administration, about 2 days post-administration, about 3 days post-administration, about 4 days post-administration, about 5 days post-administration, or about 6 days post-administration. In other aspects of this embodiment, the drug delivery platform releases a compound disclosed herein with substantially first order release kinetics over a period of time of at most 1 day post-administration, at most 2 days post-administration, at most 3 days post-administration, at most 4 days post-administration, at most 5 days post-administration, or at most 6 days post-administration.

Aspects of the disclosure include, in part, administering a RXR agonist, or a combination of a RXR agonist and a thyroid hormone, such as thyroxine. As used herein, the term "administering" means providing any delivery mechanism of a compound, composition, or combination disclosed herein to an individual that may result in a clinically, therapeutically, or experimentally beneficial result.

The co-administration of the RXR agonists disclosed herein with thyroid hormones may include various enteral or parenteral methods alone, including, but not limited to, oral administration in any acceptable form, such as tablets, liquids, capsules, powders, and the like; topically administered in any acceptable form, such as drops, spray, cream, gel or ointment; oral, nasal and/or inhalation administration in any acceptable form; rectally in any acceptable form; vaginal administration in any acceptable form; intravascular administration in any acceptable form, such as intravenous bolus, intravenous infusion, intra-arterial bolus, intra-arterial infusion, and catheter perfusion into the vasculature; peri-and intra-tissue administration in any acceptable form, such as intraperitoneal, intramuscular, subcutaneous, intraocular, retinal or subretinal injection or epidural injection; intravesicular administration in any acceptable form, such as catheter instillation; by deploying a device, such as an implant, stent, patch, pellet, catheter, osmotic pump, suppository, bioerodible delivery system, non-bioerodible delivery system, or another implanted extension or slow release system. An exemplary list of biodegradable Polymers and methods of use are described, for example, in Handbook of biodegradable Polymers (Abraham j. domb et al, eds., overturas publica association, 1997).

The compounds, compositions or combinations disclosed herein can be administered to a mammal using a variety of routes. Routes of administration suitable for treating the muscle disorders disclosed herein include local and systemic administration. Topical administration may result in significantly more delivery of the compound, composition or combination at a particular location in the mammal than throughout the body, whereas systemic administration may result in delivery of the compound, composition or combination substantially throughout the body of the individual.

One of ordinary skill in the art will determine the actual route of administration of a compound, composition or combination used herein by considering factors including, but not limited to, the duration of desired treatment, the degree of desired relief, the duration of desired relief, the particular compound, composition or combination, the rate of excretion of the compound, composition or combination used, the pharmacodynamics of the compound, composition or combination used, the nature of the other compounds included in the composition or combination, the particular route of administration, the specificity, medical history and risk factors (e.g., age, weight, general health, etc.) of the individual, the response of the individual to treatment, or any combination thereof. Thus, an effective dose of a compound, composition or combination disclosed herein can be readily determined by one of ordinary skill in the art, taking into account all conditions and using his best judgment for the individual.

In one embodiment, a compound, composition or combination disclosed herein is administered to a mammal systemically. In another embodiment, a compound, composition or combination disclosed herein is administered topically to a mammal. In one aspect of this embodiment, a compound, composition or combination disclosed herein is administered to a muscle disease site of a mammal.

In other embodiments, the RXR agonist may be administered orally, buccally, intranasally and/or by inhalation, intravascularly, intravenously, intraperitoneally, intramuscularly, subcutaneously, intraocularly, epidurally or by intravesicular administration; thyroxine may be administered orally or subcutaneously or by other routes. The RXR agonist and thyroid hormone need not be administered by the same route or at the same time of administration.

Aspects of the present specification, in part, provide a therapeutically effective amount of a RXR agonist in combination with a thyroid hormone. As used herein, the term "therapeutically effective amount" is synonymous with "therapeutically effective dose" and, when used to treat a muscle disease, refers to the dose of a compound, composition or combination necessary to achieve the desired therapeutic effect, including a dose sufficient to reduce tumor burden or bring a patient into clinical remission.

In addition, where repeated administrations using the compounds, compositions, or combinations disclosed herein are used, the actual effective amount of the compounds, compositions, or combinations disclosed herein will further depend on factors including, but not limited to, the frequency of administration, the half-life of the compounds, compositions, or combinations disclosed herein. One of ordinary skill in the art understands that an effective amount of a compound or composition disclosed herein can be extrapolated by in vitro assays and in vivo administration studies using animal models prior to administration to humans. The large differences in the necessary effective amounts are to be expected in view of the different efficiencies of the various routes of administration. For example, oral administration typically requires higher dosage levels than administration by intravenous or intravitreal injection. These variations in dosage levels can be adjusted using standard empirical optimization procedures well known to those of ordinary skill in the art. The precise therapeutically effective dose level and pattern will preferably be determined by the attending physician considering the above considerations.

By way of non-limiting example, a therapeutically effective amount can generally be from about 0.001 mg/day to about 3000 mg/day when the RXR agonist disclosed herein is administered to a mammal. In some aspects of this embodiment, an effective amount of a compound or composition disclosed herein can be about 0.01 mg/day to about 0.1 mg/day, about 0.03 mg/day to about 3.0 mg/day, about 0.1 mg/day to about 3.0 mg/day, about 0.3 mg/day to about 3.0 mg/day, about 1 mg/day to about 3 mg/day, about 3 mg/day to about 30 mg/day, about 10 mg/day to about 30 mg/day, from about 10 mg/day to about 100 mg/day, from about 30 mg/day to about 100 mg/day, from about 100 mg/day to about 1000 mg/day, from about 100 mg/day to about 300 mg/day, from about 1000 mg/day to about 3000 mg/day, from about 1 mg/day to about 100 mg/day, or from about 1 mg/day to about 20 mg/day. In other aspects of this embodiment, a therapeutically effective amount of a compound or composition disclosed herein can be at least 0.001 mg/kg/day, at least 0.01 mg/day, at least 0.1 mg/day, at least 1.0 mg/day, at least 3.0 mg/day, at least 10 mg/day, at least 30 mg/day, at least 100 mg/day, at least 300 mg/day, or at least 1000 mg/day. In still further aspects of this embodiment, a therapeutically effective amount of a compound or composition disclosed herein can be up to 0.001 mg/day, up to 0.01 mg/day, up to 0.1 mg/day, up to 1.0 mg/day, up to 3.0 mg/day, up to 10 mg/day, up to 30 mg/day, up to 100 mg/day, up to 300 mg/day, up to 1000 mg/day, or up to 3000 mg/day.

Suitable doses of thyroxine will generally be initially administered orally at about 12.5 μ g/day to about 250 μ g/day, increasing as doses of about 12.5 to about 25 μ g per day every 2-4 weeks as needed. In other embodiments, suitable thyroxine doses are from about 5 μ g/day to about 225 μ g/day, from about 7.5 μ g/day to about 200 μ g/day, from about 10 μ g/day to about 175 μ g/day, from about 12.5 μ g/day to about 150 μ g/day, from about 15 μ g/day to about 125 μ g/day, from about 17.5 μ g/day to about 100 μ g/day, from about 20 μ g/day to about 100 μ g/day, from about 22.5 μ g/day to about 100 μ g/day, from about 25 μ g/day to about 100 μ g/day, from about 5 μ g/day to about 200 μ g/day, from about 5 μ g/day to about 100 μ g/day, from about 7.5 μ g/day to about 90 μ g/day, from about 10 μ g/day to about 80 μ g/day, From about 12.5 μ g/day to about 60 μ g/day or from about 15 μ g/day to about 50 μ g/day. Dose escalation is typically performed in increments of about 5 μ g/day, about 7.5 μ g/day, about 10 μ g/day, about 12.5 μ g/day, about 15 μ g/day, about 20 μ g/day, or about 25 μ g/day. In certain embodiments, for laboratory testing, a suitable thyroid hormone dose is a dose capable of producing a T4 serum level of the top 50%, the top 60%, the top 70%, the top 80%, or the top 90% of the normal range. Since the normal range of T4 levels may vary from test laboratory to test laboratory, the target T4 level is the normal range determined from each particular test laboratory.

Administration can be single dose or cumulative (continuous administration) and can be readily determined by one skilled in the art. For example, treatment of a muscle disorder can comprise a single administration of an effective dose of a compound, composition, or combination disclosed herein. As a non-limiting example, an effective dose of a compound, composition or combination disclosed herein can be administered to a mammal in a single injection or deposition at or near the site of manifestation of symptoms of a muscle disease or in a single oral administration of the compound, composition or combination. Alternatively, treating a muscle disease can comprise administering an effective dose of a compound, composition, or combination disclosed herein multiple times over a period of time, e.g., daily, every few days, weekly, monthly, or yearly. As a non-limiting example, a compound, composition, or combination disclosed herein can be administered to a mammal once or twice a week. The time of administration will vary from mammal to mammal depending on such factors as the severity of the symptoms in the mammal. For example, an effective dose of a compound, composition, or combination disclosed herein can be administered to a mammal once a month for an indefinite period of time or until the mammal no longer requires treatment. One of ordinary skill in the art understands that the condition of the mammal can be monitored throughout the treatment and the effective amount of the compound, composition, or combination disclosed herein administered can be adjusted accordingly.

In other embodiments, the method still further comprises measuring the C of the RXR agonist of the patient_maxAnd adjusting the dosage to achieve C in the patient_maxMaintained at an optimum level.

In one embodiment, the RXR agonist is 3, 7-dimethyl-6 (S),7(S) -methanone, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydro-naphthalen-7-yl]2(E),4(E) heptanedioic acid or salts or esters thereof, and in another embodiment, the RXR agonistOr a salt or ester thereof. In another embodiment, the RXR agonist may be LG268(LG100268, LGD268, 2- [1- (3,5,5,8, 8-pentamethyl-5, 6,7, 8-tetrahydro-2-naphthyl) cyclopropyl]Pyridine-5-carboxylic acid) or a salt or ester thereof.

In some embodiments, the method further comprises treating the patient with one or more triglyceride lowering agents.

Non-limiting examples of muscle disorders that can be treated using the compounds, compositions, or combinations disclosed herein include, but are not limited to, acid maltase deficiency, anergy, atrophy, dyskinesia, Bell's Muscular Dystrophy (BMD), myocardial ischemia, myocardial infarction, cardiomyopathy, carnitine deficiency, carnitine palmitoyl transferase deficiency, central axis vacancy disease (CCD), central nuclear (myotube) myopathy, cerebral palsy, fascial compartment syndrome, channelopathy, Congenital Muscular Dystrophy (CMD), corticosteroid myopathy, spasticity, dermatomyositis, distal muscular dystrophy, Duchenne Muscular Dystrophy (DMD), dystrophic disorders (dynophopathies), Emery-Dreifuss muscular dystrophy (EDMD), facioscapulohumeral muscular dystrophy (FSHD), fibromyalgia, fibrositis, Limb Girdle Muscular Dystrophy (LGMD), Mcal calder's syndrome, Mcal-Kandel's syndrome, and/or combinations thereof, Muscular dystrophy, muscle fatigue, myasthenia gravis, myofascial pain syndrome, myopathy, myotonia, myotonic dystrophy (DM, type 1 or type 2; Steinert's disease), linear myopathy, oculopharyngeal muscular dystrophy (OCM), myoglobinuria, paramyotonia congenita (Eulenberg's disease), polymyositis, rhabdomyolysis, sarcoidosis (sarcophagia) or myospasm. In some embodiments, the myopathy is dermatomyositis, inclusion body myositis, or polymyositis. In certain embodiments, the muscle disease is caused by cancer, HIV/AIDS, COPD, chronic use of steroids, fibromyalgia, or skeletal muscle myopathy.

In other embodiments, a combination of rexinoids and thyroid hormones is beneficial by achieving myocardial protection or regeneration in vivo or in vitro to facilitate subsequent implantation of myocytes into damaged myocardium.

Also provided herein are methods of treating a muscle disorder comprising administering to a subject in need thereof a therapeutically effective amount of 3, 7-dimethyl-6 (S),7(S) -methanone, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydronaphthalen-7-yl ]2(E),4(E) heptadienoic acid, and a therapeutically acceptable amount of thyroxine; and wherein the co-administration reduces the severity of the muscle disease in the patient by slowing or stopping progression, or inducing or accelerating repair or regeneration of affected muscles (muscles) or muscles (muscles).

Non-limiting examples of symptoms that are ameliorated or alleviated by the methods of treating muscle disorders disclosed herein include, but are not limited to, weakness, fatigue, stiffness, pain, spasticity, movement disorders, muscle relaxation, exercise intolerance, facial erythema, cachexia, metabolic disorders, dysphagia, aphasia, rash, periungual congestion, telangiectasia, subcutaneous nodules and calcification, ulcers, lesions, and ptosis.

In some embodiments, the method can be used to treat muscular dystrophy. Muscular dystrophy is a group of genetic diseases in which the muscles of a patient gradually deteriorate and weaken and the muscle mass declines. Muscular dystrophy was diagnosed by health examination, patient history assessment, blood examination (serum creatinine kinase levels, serum aldolase, aspartate Aminotransferase (AST), Lactate Dehydrogenase (LDH), and myoglobin), muscle biopsy, exercise assessment, genetic, neurological, cardiac, pulmonary, and imaging tests.

In some embodiments, the method can be used to ameliorate or reduce muscular dystrophy. Symptoms of muscular dystrophy include, but are not limited to, restricted or delayed motor skill development, muscle weakness, muscle spasms, blepharoptosis, dysphagia, aphasia, vision problems, and watery mouth. In other embodiments, the method can treat or alleviate complications associated with muscular dystrophy. Complications associated with muscular dystrophy may include, but are not limited to, cardiomyopathy in heart failure, cataracts, hypokinesia, depression, lung failure, contractures, mental injury, and scoliosis.

In some embodiments, the method can reduce serum aldolase levels in the patient. In other embodiments, the method can reduce the aldolase level in the patient to about 3.0Sibley-Lehninger units/dL to about 8.0Sibley-Lehninger units/dL, or about 3.0Sibley-Lehninger units/dL to about 9.0Sibley-Lehninger units/dL, or about 20mU/L to about 60 mU/L.

In other embodiments, the method can reduce serum creatinine levels in the patient. In other embodiments, the method can reduce the serum creatinine level of the patient to about 5IU/L to about 100IU/L (male), about 10IU/L to about 70IU/L (female).

In some embodiments, the method can reduce AST levels in the patient. In other embodiments, the method may reduce the AST level in the patient to between about 5IU/L and about 35IU/L or between about 5IU/L and about 40 IU/L.

In some embodiments, the method can reduce LDH levels in a patient. In other embodiments, the method can reduce the LDH level in the patient to between about 290U/L and about 775U/L (patients between about 0 and about 4 days); between about 545U/L and about 2000U/L (patients between about 4 days to about 10 days); between about 180U/L and about 430U/L (patients between about 10 days and about 24 months); between about 110U/L and about 295U/L (in patients between about 24 months and about 12 years of age); between about 100U/L and about 190U/L (in patients between about 12 years of age and about 60 years of age); or between about 110U/L and about 210U/L (for patients 60 years of age or older).

In some embodiments, the method can reduce the myoglobin level of the patient. In other embodiments, the method can reduce the patient's myoglobin level to between about 0ng/mL to about 85 ng/mL.

In some embodiments, the method can reduce Creatinine Phosphokinase (CPK) levels in the patient. In some embodiments, the method can reduce the patient's CPK level to between about 22U/L to about 198U/L.

In some embodiments, the ventricular ejection fraction is measured. Ventricular ejection fraction is a reflection of heart health and is determined by echocardiography, nuclear stress testing, CAT scanning, cardiac catheterization, or radionuclide ventricular angiography (or radionuclide angiography; MUGA). In some embodiments, the ventricular ejection fraction is normalized to between 50 and 70 as a result of the disclosed methods.

The compounds, compositions or combinations disclosed herein can also be administered to a mammal in combination with other therapeutic compounds to increase the overall therapeutic effect of the treatment. Treatment of indications with multiple compounds can increase the beneficial effects while reducing the presence of side effects.

Aspects of the description may also be described as follows:

examples

The following non-limiting examples are provided for illustrative purposes only to facilitate a more complete understanding of the presently contemplated representative embodiments. These examples should not be construed as limiting any of the embodiments described in this specification, including methods relating to the treatment of a muscle disorder using the RXR agonists disclosed herein in combination with thyroid hormones, the use of the RXR agonists disclosed herein and thyroid hormones for the manufacture of a medicament for the treatment of a muscle disorder.

Example 1

Selective RXR agonists, IRX4204, exert their biological effects through RXR signaling

To determine whether a RXR agonist can modulate its effect through a RXR α receptor homodimer, a RXR β receptor homodimer, a RXR γ receptor homodimer, or any combination thereof, or the corresponding RAR/RXR heterodimers, receptor-mediated transactivation assays were performed for transactivation assays to assess RXR homodimer signals, CV-1 cells were transfected with 1) an expression vector comprising full-length RXR α, RXR β, or RXR γ, and 2) a crbpii/RXRE-tk-Luc reporter construct comprising a RXR homodimer-specific RXRE/DR1 response element linked to a luciferin gene, for transactivation assays to assess RAR/RXR dimer heterodimer signals, CV-1 cells were transfected with 1) a fusion protein comprising a hormone receptor (RAR) DNA binding domain linked to a RAR α, RAR β, or female RAR γ ligand binding domain linked RAR, and 2) a fusion protein comprising a hormone receptor (RAR) DNA binding domain linked to an estrogen gene, RXR-expressing the expression vector and 2) a luciferase receptor-receptor (RAR) fusion protein expressing the activity of RXR-expressing the maximum RXR activity after transfection assay using a full-20 μ r agonist assay to provide an increasing percent RXR activity reading for the cells treated with RXR-5 cells.

TABLE 1 RXR agonists ability to activate RXR and RAR

These results show thatThe RXR agonist IRX4204 activates the RXR receptor and has very high potency (EC) against all three RXR subtypes₅₀<0.5nM) (Table 1). In contrast, EC of RXR agonists on RARs₅₀>1000nM, minimal activity detected at ≥ 1 μ M. This difference indicates that RXRs are more selective than RARs in functional transactivation assays>2000 times. Furthermore, these data indicate that the RXR agonist IRX4204 is 1000-fold more potent at activating the RXR receptor than the RAR receptor. These results indicate that the biological effects of selective agonists such as IRX4204 are mediated through the RXR signaling pathway, rather than through the RAR signaling pathway. Furthermore, by using appropriate receptor and reporter constructs, it was shown that the RXR agonist IRX4204 is not transactivating for the so-called "permissive RXR heterodimers" PPAR/RXR, FXR/RXR and LXR/RXR (fig. 1A-C). In this regard, the RXR agonist IRX4204 is distinct from other RXR agonists. In addition, IRX4204 selectively activates the Nurr1/RXR permissive heterodimer (fig. 1D). Therefore, the RXR agonist IRX4204 is unique in that it selectively activates only RXR homodimers and Nurr1/RXR heterodimers.

Example 2

Affinity of RXR agonists

Expression of RXR α, RXR β, RXR γ, RAR α, RAR β or RAR γ in SF21 cells using a baculovirus expression system and purification of the resulting proteins to determine the affinity of RXR agonists to RXR, purified RXR α, RXR β, RXR γ and 10nM, respectively³H]-9CRA incubation and the affinity of the RXR agonist IRX4204 is determined by competitive displacement of³H]Purified RAR α, RAR β and RAR γ were used at 5nM [ alpha ], [ alpha ]³H]-ATRA incubation, the affinity of the RXR agonist IRX4204 being determined by competitive displacement of [ alpha ], [ beta ] -from the receptor³H]ATRA. The Ki values are the average of at least two independent experiments (table 2). Standard error (±) in independent experiments is shown.

As shown in table 2, the RXR agonist IRX4204 showed high affinity for RXR α, RXR β and RXR γ with Ki values of 1.7, 16 and 43 nM. respectively, in contrast to the RXR agonist IRX4204 which had very low affinity for each RAR (Ki values >1000 nM).

TABLE 2 affinity of RXR agonists

Example 3 RXR agonist IRX4204 as a Selective activator of Nurr1/RXR permissive heterodimers

To determine which permissive RXR heterodimers were activated by RXR agonist IRX4204, receptor transactivation assays were performed as follows for PPAR γ/RXR, FXR/RXR, LXR α/RXR, LXR/RXR and Nurr1/RXR for PPAR γ: CV-1 cells were transfected with 3x (rAOX/DR1) -tk-Luc reporter and PPAR γ expression vector for FXR: CV-1 cells were transfected with 3x (IBABP/IRI) -tk-Luc reporter and vectors for FXR and RXR α for LXR: CV-1 cells were transfected with 3x (PLTP/DR re) -tk-Luc reporter and vectors for LXR α or LXR β for LXR nu 1: full length nrr 8295-1 cells with 3xNBRE reporter and full length RXR 829-Luc for RXR and with RXR 4 or without RXR agonist irr 4. RXR 4204. RXR agonist activity was then normalized to the maximum activity data (LXR 4204. RXR/RXR activating map) and RXR γ expression data for LXR γ 2. LXR, LXR 2. LXR activation assays were performed as shown by LXR/RXR agonist activity (RXR/RXR 4204. RXR/RXR 4204. RXR co-1 cells), LXR activation data for LXR, LXR 2. LXR activation data, LXR activation data (RXR)₅₀<1nm) Nurr1/RXR heterodimer (FIG. 2D). Together, these data indicate that IRX4204 is a unique RXR agonist because it selectively activates the Nurr1/RXR heterodimer but not the PPAR γ/RXR, FXR/RXR or LXR/RXR heterodimers.

Example 4

Effect of RXR agonists on oligodendrocyte precursor cell differentiation

The purpose of this study was to evaluate the effect of IRX4204 on the differentiation of Oligodendrocyte Precursor Cells (OPCs) into oligodendrocytes. OPCs were produced from a neurosphere culture of E14.5PLP-EGFP (on a C57BL/6J background) mouse brain. Isolated OPCs were treated with IRX4204 and/or T3 to assess the Expression of Green Fluorescent Protein (EGFP), which is associated with the differentiation of OPCs into oligodendrocytes. EGFP expressing cells were quantified using a cytological neurological analysis Algorithm (Cellomics neural Profiling Algorithm). The positive (T3) control demonstrated the expected differentiation of OPCs. As a result, an increase in the number of EGFP-positive cells compared to the negative control (DMSO) indicates that IRX4204 promotes the differentiation of OPC into oligodendrocytes. All concentrations tested showed a significant increase in the differentiation of OPC into oligodendrocytes (fig. 3). However, the addition of T3 to IRX4204 treated cultures induced even higher EGFP + oligodendrocyte levels, demonstrating that the effect of IRX4204 and thyroid hormone combination was significant.

EGFP expressing cells were quantified in the control group and in all compounds using a cytological neuronic Profiling Algorithm (Cellomics neural Profiling Algorithm). This experiment was successful as demonstrated by a significant increase in% EGFP cells in the positive control (T3; 8.5%) compared to the negative control (DMSO 2.3%). IRX4204 promotes the differentiation of OPCs into oligodendrocytes as demonstrated by a dose-dependent increase in the number of EGFP-positive cells compared to negative control (DMSO). IRX4204 did not show any difference in total cell number and pycnotic cells compared to the control. The results of this study indicate that IRX4204 promotes OPC differentiation. The data show a dose-dependent increase in the percentage of EGFP cells compared to the negative control. These data indicate that IRX4204 promotes the growth of myelin forming cells in cell culture.

Example 5

Differentiation of mouse oligodendrocyte progenitor cells

The objective of this study was to evaluate the possible effect of IRX4204 in combination with triiodothyronine (T3) on the differentiation of mouse Oligodendrocyte Progenitor Cells (OPCs) into oligodendrocytes. OPCs were derived from plp-EGFP expressing mice.

Therapeutic agents were tested in 96-well plates (6 wells per concentration). Negative and positive controls (DMSO or 10ng/ml T3 thyroid hormone) were included in each plate. All media contained 0.1% DMSO. At the end of the 5 day treatment, cells were imaged in two channels on Cellomics and the nuclei and EGFP + oligodendrocytes were counted using an algorithm.

FIGS. 5A-C show the apparent dose response of oligodendrocyte production to different doses of IRX4204 and T3. Under all conditions, oligodendrocyte production was greater in the combination therapy of RX4204 and T3 than in the individual treatments. This indicates that IRX4204 and T3 have additive or potentially synergistic effects in driving oligodendrocyte precursor cell differentiation. Similar results were obtained when cells were stained with MBP antibody and quantified (data not shown). These data indicate that the combination of IRX4204 and T3 (or T4) is optimal in remyelination.

Example 6

Assessment of neuroprotective potential of IRX4204 and IRX4204+ thyroxine in a non-immune mediated demyelinating mouse model

The modified cuprizone model (cuprizone + rapamycin) facilitates reliable, reproducible and unambiguous analysis of neurodegeneration caused by demyelination. SMI-32 immunostaining allows visualization and quantification of swollen and transected axons (ovoids) in callus and allows assessment of the degree of axonal degeneration. There were four groups of mice in this study: copper only + rapamycin (CR) (n ═ 6), CR + vector (n ═ 12), CR + IRX4204(n ═ 12) and CR + IRX4204+ thyroxine (n ═ 12). The test article was administered simultaneously with CR for 6 weeks. IRX4204 is orally administered once daily at 10mg/kg body weight. Thyroxine (T4) treatment was initiated one day after initiation of IRX4204 treatment. T4 was administered once daily Subcutaneously (SC) at 20ng/g body weight. The CR + vehicle group received IRX4204 vehicle (oral) and T4 vehicle (SC). Terminal blood was collected from all animals to determine plasma T4 levels. After sacrifice, the density of SMI-32 positive ovoids per unit area of each group was determined. The higher the density of SMI-32 positive ovoids, the greater the degree of axonal degeneration. SMI-32+ ovaloid was reduced by 13.3% in the IRX4204 group relative to the vector group, indicating that only IRX4204 had some neuroprotective effect. However, a 37.5% reduction in the IRX4204+ thyroxine group relative to the vehicle group indicates that IRX4204 in combination with thyroxine provides a considerable degree of neuroprotective effect of CR-induced neurotoxicity by inhibiting axonal transection in the corpus callosum (figure 7).

Example 7

Neuroprotective effects of IRX4204 in demyelinating mouse models

The aim of this study was to evaluate the neuroprotective effect of IRX4204 in a non-immune mediated demyelinating mouse model.

In this study, the neuroprotective potential of IRX4204 was evaluated after 6-week synchronized treatment during demyelination using a 6-week demyelination model. Subgroups were treated with T4 and IRX 4204. The results of this study indicate that IRX4204 promotes neuroprotection without reducing the degree of demyelination in the corpus callosum.

Animals (8-week-old male C57BL/6J mice) were subjected to a 6-week copper diet and rapamycin injection (CR) to induce demyelination. During demyelination, animals were treated daily with either vector or IRX4204(10mg/kg, PO) or IRX4204+ T4(10mg/kg, PO and 20ng/g, SQ) for the entire 6 weeks. All animals were sacrificed after CR 6 weeks to assess axonal integrity and microglial/macrophage activity in white matter (corpus callosum, CC). The two groups (vector and IRX4204+ T4) were further examined for any protective effect on the extent of myelination in CC.

Axonal transection was significantly reduced as shown by the reduction in the number of SMI32 positive axonal ovoids in animals treated with IRX4204+ T4. However, there was no difference in microglia/macrophage activity and the number of myelinated axons in CC between the vector and the IRX4204+ T4 group. These findings support the neuroprotective effect of IRX4204, which is mediated by a potentially direct effect on demyelinated axons.

A total of 50 animals were included in this study, of which 43 received CR demyelination for 6 weeks. During demyelination, a portion of the (n-7) animals were kept on a normal diet for use as a young matched control. The remaining animals received IRX4204(n ═ 14) or vehicle (n ═ 14) or IRX4204+ T4(n ═ 15) simultaneously during CR for 6 weeks. There was no death during life. In addition, no health problems were observed during the treatment period. All animals remained alert and showed proper grooming behavior. ANOVA analysis of multiple group comparisons showed no significant difference in final body weight between IRX4204 and the vehicle group.

To assess thyroid hormone levels, terminal blood draws were taken to quantify the level of T4. The level of T4 was reduced by about 50% in animals treated with IRX4204 alone compared to vehicle control animals. Exogenous treatment of T4 corrected thyroid hormone levels as indicated by an increase in T4 levels in the IRX4204+ T4 group.

Floating brain sections were immunostained with SMI-32 to allow visualization and quantification of axonal eggs in CCs. Animals receiving CR had significantly higher numbers of SMI32 stained axonal eggs in CC compared to young animals. The number of axonal eggs was significantly reduced in animals treated with IRX4204 and T4 compared to vehicle. IRX4204 alone showed a trend towards a reduction in the number of axonal eggs, but was not statistically different from the vehicle.

Immunostaining was performed with Iba-1 floating brain sections to allow visualization and quantification of microglia/macrophages in CC. Compared to young animals, animals receiving CR and treated with vehicle showed a strong increase in Iba1 staining in CC compared to young animals. There was no difference in Iba1 staining levels in IRX4204 or IRX4204+ T4 treated animals compared to vehicle.

Half-thin (1 μm) sections of Epon-embedded CC tissue from animals receiving CR and vector or IRX4204+ T4 were used for visualization and quantification of the number and density of myelinated axons in the CC. Animals receiving CR and vehicle showed significant CC demyelination. There was no significant difference in the number and density of myelinated axons in IRX4204+ T4 treated animals compared to vehicle.

Treatment with IRX4204 alone, but not with T4, showed a trend of axon egg reduction, but was not statistically different from the vehicle. However, when the animals receiving IRX4204 were supplemented with exogenous T4, the number of axon eggs was significantly reduced compared to the vehicle. This data together with our previous in vivo findings support the neuroprotective effect of IRX 4204. Although the axonal ovoids were reduced, there was no significant difference in microglial/macrophage activity and myelination in the vector and the corpus callosum of IRX4204+ T4 group.

The finding that IRX4204 only showed neuroprotective effect in the group with supplemental T4 suggests that the combination therapy has an enhanced effect relative to IRX4204 alone.

Quantification of myelinated axons in the corpus callosum revealed potential responders and non-responders. FIGS. 9A-C show a high correlation between axonal ovoids and the number of myelinated axons (i.e., animals with very few ovoids in the corpus callosum have very high number and density of myelinated axons).

Example 8

Role of IRX4204 in Parkinson's disease model

The objective of this study was to evaluate the improvement of IRX4204 treatment on behavioral deficits in the rat 6-OHDA-induced Parkinson's Disease (PD) model. A rat model of PD was generated by unilateral intrastriatal injection of neurotoxin 6-hydroxydopamine (6-OHDA). This injection produced Dopaminergic (DA) neuron loss on the injection side while preserving the contralateral DA neurons. The study design is shown in table 3.

TABLE 3

The paw position (cylinder test) was used to assess damage. This test evaluates the use of a rat's independent forelimb to support the body on the wall of a cylindrical enclosure. The test exploits the innate driving force of animals to explore a new environment by standing on hind limbs and close to the fence.

To perform the test, the rats were individually placed in glass cylinders (diameter 21cm, height 34cm) and wall probing was recorded for 3 minutes. The cylinder is not allowed to adapt before recording.

Statistical analysis was performed as the ratio between intact and damaged legs (R/L ratio). The ratio is expressed as the value of the intact right + two forelimbs divided by the value of the damaged left + two forelimbs. Lower ratios mean stronger healing of 6-OHDA induced brain injury.

All treated animals gained weight throughout the study. On days 17 and 24 of the study, the average body weight of animals treated with test sample IRX4204(TA1) and vehicle TA2 (group 2) or in combination with thyroxine and triiodothyronine (TA 2; group 4) was significantly higher than that of vehicle treated group (group 1) (day 24, group 2 was 157.17. + -. 2.93%, group 4 was 157.61. + -. 3.54%, vehicle group was 142.62. + -. 2.93%; p < 0.05).

All animals with R/L ratios >1.5 were included in the study (the ratio between intact (R) and injured leg (L) was expressed as intact right + two forelimb values divided by injured left + two forelimb values).

Paw placement positions were measured before induction of injury (baseline) and 3 days post 6-OHDA injection (one day before IRX4204 treatment). Animals were retested for performance in paw placement tests once a week for three weeks (study days 10, 17 and 24).

Animals were pre-selected on study day 3 based on R/L ratio when the mean ratio between the injured side and intact side increased relative to baseline levels (1.01 ± 0.01 before surgery, 6.49 ± 0.59 three days after surgery).

As shown in FIG. 4, on study day 10, treatment with IRX4204(TA1) in combination with either vector TA2 (group 2) or with thyroxine and triiodothyronine (TA 2; group 4) significantly reduced the mean calculated R/L ratio (2.76. + -. 0.57 for group 2, 2.86. + -. 0.76 for group 4, 6.33. + -. 1.41 for group carrier; p <0.05) compared to the vector treated group (group 1).

On study days 17 and 24, the mean calculated ratio was lower in these groups compared to the vehicle group, but the ratio was not statistically significant.

The average of the ratios was calculated from four values on day 3, day 10, day 17 and day 24. The calculated values for group 2 and 4 were 3.79 and 3.14, respectively. This indicates that group 4 (IRX4204 in combination with thyroxine and triiodothyronine) is more effective than group 2 (IRX4204) alone.

Example 9

Human clinical trials demonstrating the role of IRX4204 in parkinson's disease

A non-blind, single-center clinical study of subjects treated with IRX4204 for early stage parkinson's disease was conducted to determine whether the preclinical desirability of IRX4204 as a disease modifier for PD would translate into clinical use according to the unified parkinson's disease rating scale (UPSRS) measurements and safety assessments after treatment of early stage PD patients with IRX 4204. Changes in the UPDRS score correlated with circulating thyroxine levels.

The objective of this study was to further characterize the safety and tolerability of IRX4204 in early stage patients, especially in patients with reduced levels of T4, and to evaluate the therapeutic efficacy of motor symptoms of PD as measured by UPDRS following treatment with IRX 4204.

The study endpoints were (1) the change in exercise test score from the end of the dosing period (day 17), and (2) the change in T4 levels.

This is a single-center, non-blind study aimed at examining the effectiveness ((reduction of UPDRS score) and safety, for a period of about two weeks) of 3 dose levels of IRX4204 on a population of early PD patients in which each subject in at least 3 cases needs to report to the clinical study site:

screening (visit 1) -screening to determine eligibility (up to 30 days before baseline visit)

Baseline period (visit 2) -day 1 of starting treatment with IRX 4204.

Week 2 (visit 3) -subjects returned to the clinic for safety and efficacy assessment approximately 17 days after the start of IRX 4204.

Safety and tolerability were assessed by all study visits including blood and urine samples for laboratory testing, ECG, physical examination, neurological examination and assessment of adverse reactions.

To qualify for study participation, subjects were asked to meet the following criteria: 40-80 years old (including 40 and 80 years old); clinical diagnosis of PD according to UK Brain Bank Criteria (UK Brain Bank criterion); participants' Hoehn and Yahr ratings < 3; participants may be treated with a stable dose of PD symptom therapy for at least 30 days prior to the screening visit. The dose level of PD symptom therapy in this study will remain stable; must be willing and able to provide a consent form; women must have non-fertility potential or must be willing to avoid pregnancy by using medically accepted contraceptive measures 4 weeks before the study and 4 weeks after the last dose of study medication.

Subjects who meet any of the following criteria are not included in the study: parkinson's disease in any form other than congenital PD; is currently experiencing fluctuations in symptoms (hypopharmacodynamics or dyskinesias) that reflect later stages of PD; evidence of dementia or severe cognitive dysfunction; a medical or psychiatric disease with clinically significant abnormal laboratory value and/or clinically significant instability; the subject has any disease that may interfere with drug absorption, distribution, metabolism, or excretion; the subject has clinically significant evidence of gastrointestinal, cardiovascular, hepatic, pulmonary or other disorders or diseases; pregnancy or lactation.

The clinical site prepared the study drug for administration by assigning the correct dose (20 mg/day, 10 mg/day or 5 mg/day) of IRX4204 to each subject. On day 1, subjects received their first dose of IRX 4204. After day 1, IRX4204 drug administration was performed daily at home. Patients take their daily dose of study medication with food approximately at the same time each day, preferably between 8 am and 10 am. On day 1, subjects received a 15 day supply of IRX4204 at a once daily dose of 20mg, 10mg or 5 mg. Five subjects were enrolled at each of the three dose levels. All 15 subjects completed 15 days dosing.

All subjects (total n-52, n-12-13 per dose level) completed 15 days dosing and returned to the clinic at the end of 2 weeks (days 15-17) for UPDRS scoring and safety assessments, including determination of plasma thyroxine (T4) levels. The percent change in total motor score, total UPDRS score, and plasma T4 values were determined according to the following methods:

the mean percent change in total exercise and total UPDRS scores for the three dose levels are given in table 4. Negative scores indicate disease improvement, as measured by the comprehensive UPDRS assessment. The lowest dose of IRX4204(5 mg/day) gave the maximum therapeutic response (-31.4%) of IRX4204 treatment as measured by total exercise score. Surprisingly, efficacy decreased by total exercise score at 10 mg/day (11.7%) and 20 mg/day (-14.5%) at each higher dose. Similar results were obtained when the Total UPDRS score was considered. The best therapeutic response was obtained with the 5 mg/day cohort (-18.7%). At each higher dose, 10 mg/day and 20 mg/day, the efficacy declined gradually with changes in Total UPDRS of-13.6% and 6.6%, respectively.

TABLE 4

Dosage form	Total change of motion	Total UPDRS changes
			20 mg/day	-14.5％	-6.6％
10 mg/day	-11.7％	-13.6％
			5 mg/day	-31.4％	-18.7％

The mean percent change in plasma T4 levels for the three cohorts is given in table 5. The relationship between dose level and percent reduction in plasma thyroxine (T4) is direct: the higher the dose of IRX4204, the greater the decrease in T4. IRX4204 at a dose of 20 mg/day resulted in almost complete disappearance of plasma T4 (98.8% reduction). Interestingly, this high dose of IRX4204 correlated with the lowest efficacy (only a 6.6% reduction in total UPDRS score).

TABLE 5

Dosage form	TSH variation
		20 mg/day	-98.8％
10 mg/day	-36.6％
		5 mg/day	-28.9％

These data in human clinical trials clearly indicate that a decrease in thyroid hormone levels following administration of IRX4204 negatively affects the therapeutic benefit of IRX 4204. Data from clinical trials showed an inverse relationship between inhibition of the thyroid axis (manifested as inhibition of TSH, thyroid stimulating hormone) and baseline clinical improvement in total motor score and UPDRS.

Example 10

Comparison of bexarotene, IRX4204 and IRX4204+ thyroxine in cell differentiation

To determine and compare the efficacy of bexarotene, IRX4204 and IRX4204+ thyroxine in stem cell differentiation, stem cells were exposed to increasing concentrations of each compound. Pluripotent P19 cells (ATCC) were grown in culture medium, transferred to petri dishes 4 days after aggregation, and cultured on gelatin-coated coverslips in the presence of different concentrations of bexarotene, IRX4204+ thyroxine, retinoic acid, or vehicle alone, in the presence of 1% dimethyl sulfoxide (DMSO), at concentrations ranging from about 1nM to about 1 μ M.

Cells fixed on the coverslip were then incubated with a primary antibody for skeletal muscle markers and then labeled with a secondary antibody. Microscopic analysis was performed and the number of skeletal muscle cells was quantified. Treatment with IRX4204 or IRX4204+ thyroxine showed a greater number of myogenic differentiated cells compared to cells treated with retinoic acid, bexarotene or vehicle alone; treatment of IRX4204 with thyroid hormone showed a higher number of myogenic differentiated cells compared to cells treated with IRX4204 alone.

To test the efficacy of RXRs on myogenic transformation of embryonic stem cells (ES), embryoid bodies were formed in the absence of DMSO. Embryoid bodies were treated with retinoic acid, bexarotene, IRX4204+ thyroxine or vehicle alone at concentrations ranging from about 1nM to about 1 μ M and plated on coverslips and stained for musculoskeletal markers. Myoblasts were examined microscopically and the number of myocytes was counted. Cells treated with IRX4204 or IRX4204+ thyroxine were more effective at increasing differentiation than cells treated with retinoic acid, bexarotene or vehicle alone, and IRX4204+ thyroxine was more effective at increasing differentiation than IRX4204 alone.

Example 11

Comparison of IRX4204 and IRX4204+ thyroxine in myoblast differentiation

To determine and compare the efficacy of IRX4204 and IRX4204+ thyroxine in myoblast differentiation, murine skeletal myoblasts and primary myoblasts were cultured. Myogenic differentiation is initiated when cells are approximately 60-80% confluent and the cells differentiate into cell types, such as myotubes.

Cells were treated with thyroxine, IRX4204+ thyroxine or vehicle alone at concentrations ranging from about 10nM to about 1 μ M. Cells treated with IRX4204 or IRX4204+ thyroxine showed a higher number of microfibrils than cells treated with thyroxine or vehicle alone, and cells treated with IRX4204+ thyroxine showed more differentiated cells than cells treated with IRX4204 alone. Thus, IRX4204+ thyroxine was more effective in myoblast differentiation than treatment with thyroxine or IRX4204 alone.

Example 12

Therapeutic effect of bexarotene, IRX4204 or IRX4204+ thyroxine on cardiac hypertrophy

To determine and compare the efficacy of bexarotene, IRX4204 and IRX4204+ thyroxine in cardiac hypertrophy, each compound was administered to Spontaneously Hypertensive Rats (SHR) and its effect monitored. 4 week old SHR and control rats were randomized and divided into 5-10 rats/group. Each group was administered 10mg to 100mg/kg bexarotene, IRX4204a + thyroxine or vehicle alone. A cross echocardiogram is performed to determine heart weight and measurements.

When the animals reached 12 weeks of age, the heart mass and heart wall thickness were significantly increased in the SHR of animals treated with vehicle only compared to the control group. SHR treated with bexarotene, IRX4204 or IRX4204+ thyroxine showed inhibition of increase in cardiac mass and wall thickness compared to SHR treated with vehicle alone. Animals treated with IRX4204 or IRX4204+ thyroxine showed greater inhibition of increase in cardiac mass and wall thickness compared to animals treated with bexarotene, and animals treated with IRX4204+ thyroxine showed the greatest inhibition.

Animals were sacrificed at 16 weeks of age to determine cardiac hypertrophy. Hypertrophy is determined by the ratio of left ventricular weight to body weight of the animal. Myocyte cross-sectional area was also determined. From about 10mg to about 30mg of the left ventricle of the animal was homogenized and subjected to sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblot analysis.

SHR treated with bexarotene, IRX4204 or IRX4204+ thyroxine showed a significantly lower ratio of left ventricular weight to body weight compared to SHR treated with vehicle alone. Animals treated with IRX4204 or IRX4204+ thyroxine showed lower left ventricular weight to body weight ratios compared to bexarotene treated animals, and animals treated with IRX4204+ thyroxine showed the lowest left ventricular weight to body weight ratio.

Furthermore, RXR α expression was more upregulated in myocardial tissue in animals treated with IRX4204 or IRX4204+ thyroxine as compared to animals treated with bexarotene and a higher RXR α upregulation in RXR tissue in animals treated with IRX4204 or IRX4204+ thyroxine as compared to animals treated with bexarotene alone in immunoblot analysis as compared to animals treated with bexarotene.

Therefore, IRX4204 and IRX4204+ thyroxine showed greater efficacy than bexarotene in treating left ventricular hypertrophy in hypertensive rats.

Finally, it should be understood that the aspects of the present description, while highlighted by reference to specific embodiments, are readily understood by those skilled in the art that these disclosed embodiments are merely illustrative of the principles of the subject matter disclosed herein. Accordingly, it is to be understood that the disclosed subject matter is in no way limited to the specific methods, protocols, and/or reagents, etc., described herein. As such, various modifications or changes or substitutions to the disclosed subject matter may be made in accordance with the teachings herein without departing from the spirit of the present specification. Finally, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention, which will be limited only by the appended claims. Accordingly, the invention is not limited to exactly those shown and described.

Certain embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on those described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described embodiments in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

Groupings of alternative embodiments, elements or steps of the present invention should not be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other group members disclosed herein. It is contemplated that one or more members may be included in a group or deleted from a group for convenience and/or patentability. When any such inclusion or deletion occurs, the specification is considered to contain the modified group so as to satisfy the written description of all markush groups used in the appended claims.

Unless otherwise indicated, all numbers expressing features, items, quantities, parameters, properties, terms, and so forth, used in the specification and claims are to be understood as being modified in all instances by the term "about. As used herein, the term "about" means that the feature, item, quantity, parameter, property, or term so defined includes a range of ± 10% of the value of the feature, item, quantity, parameter, or term above and below. Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical indication should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and values setting forth the broad scope of the invention are approximations, the numerical ranges and values set forth in the specific examples are reported as precisely as possible. Any numerical range or value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value of a range of values is included in the specification as if it were individually recited herein.

The use of the terms "a" and "an" and "the" and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

The embodiments disclosed herein may be further limited in the claims using language consisting of, or consisting essentially of. The transitional term "consisting of" when used in a claim, whether filed or added with a modification, does not include any elements, steps or components not specified in the claim. The transitional term "consisting essentially of" limits the scope of the claims to the specified materials or steps and those that do not materially affect the basic and novel characteristics. Embodiments of the claimed invention are described and claimed herein either inherently or explicitly.

All patents, patent publications, and other publications cited and identified in this specification are herein incorporated by reference in their entirety individually and specifically for the purpose of description and disclosure, e.g., the compositions and methods described in these publications can be used in connection with the present invention. Publications disclosed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing in this regard should be construed as an admission that the inventors are not entitled to antedate such information by virtue of prior invention or for any other reason. Statements as to the date or representation as to the contents of these documents is based on the information available to the applicants and does not constitute any admission as to the correctness of the dates or contents of these documents.

Claims (23)

1. A method of treating a muscle disorder comprising administering to an individual in need thereof a therapeutically effective amount of a RXR agonist and a thyroid hormone, wherein the RXR agonist has the structure of formula II

Wherein R is H or lower alkyl of 1 to 6 carbons; bexarotene or LG 268;

wherein administration of the RXR agonist and thyroid hormone is more effective than the RXR agonist or thyroid hormone alone in treating the muscle disorder in the subject.

2. The method according to claim 1, wherein the RXR agonist is a selective RXR agonist comprising 3, 7-dimethyl-6 (S),7(S) -methano, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydronaphthalen-7-yl ]2(E),4(E) heptadienoic acid.

3. The method according to claim 1, wherein the RXR agonist is 3, 7-dimethyl-6 (S),7(S) -methano, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydronaphthalen-7-yl ]2(E),4(E) heptadienoic acid.

4. The method according to claim 1, wherein the RXR agonist is bexarotene.

5. The method according to claim 1, wherein the RXR agonist is LG 268.

6. The method of claim 1, wherein the thyroid hormone is thyroxine.

7. The method according to claim 1, wherein the therapeutically effective amount of the ester of the RXR agonist is from about 0.001 mg/day to about 1000 mg/day.

8. The method according to claim 1, wherein the therapeutically effective amount of the RXR agonist is from about 0.001 mg/day to about 1000 mg/day.

9. The method according to claim 1, wherein the therapeutically effective amount of the RXR agonist is from about 1 mg/day to about 100 mg/day.

10. The method of claim 6, wherein the dose of thyroxine is from about 12.5 μ g/day to about 250 μ g/day.

11. The method according to claim 1, wherein the RXR agonist is administered by nasal administration.

12. The method according to claim 1, wherein the RXR agonist and thyroid hormone are both administered by nasal administration.

13. The method according to claim 1, wherein the RXR agonist is administered orally.

14. The method according to claim 1, wherein the RXR agonist and the thyroid hormone are administered substantially simultaneously.

15. The method according to claim 1, wherein the RXR agonist and thyroid hormone are administered at different times.

16. The method of claim 1, wherein the thyroid hormone is administered orally.

17. The method of claim 1, wherein the thyroid hormone is administered subcutaneously.

18. The method of claim 1, wherein the method treats a condition selected from acid maltase deficiency, dystonia, atrophy, ataxia, Becker Muscular Dystrophy (BMD), myocardial ischemia, myocardial infarction, cardiomyopathy, carnitine deficiency, carnitine palmitoyl transferase deficiency, central axial vacancy disease (CCD), central nuclear (myotube) myopathy, cerebral palsy, fascial space syndrome, channelopathy, Congenital Muscular Dystrophy (CMD), corticosteroid myopathy, spasticity, dermatomyositis, Duchenne Muscular Dystrophy (DMD), dystrophic diseases (dystrophinopathies), Emery-Dreifuss muscular dystrophy (EDMD), facioscapulobrachial muscular dystrophy (FSHD), fibrositis, Limb Girdle Muscular Dystrophy (LGMD), mecader syndrome, muscular dystrophy, muscle fatigue, myasthenia gravis, myalgia syndrome, muscle pain syndrome, Myopathy, myotonia, myotonic dystrophy type 1, myotonic dystrophy type 2, linear myopathy, oculopharyngeal muscular dystrophy, fibromyalgia, polymyositis, rhabdomyolysis and myospasm.

19. The method of claim 18, wherein the myopathy is dermatomyositis, inclusion body myositis, or polymyositis.

20. The method of claim 18, wherein the muscle disease is caused by cancer, HIV/AIDS, COPD, or chronic use of cholesterol.

21. The method of claim 18, wherein the combination of a retinoid agonist and a thyroid hormone is beneficial by achieving myocardial protection or regeneration in vivo.

22. The method of claim 18, wherein the combination of the retinoid agonist and thyroid hormone is beneficial for treating muscle cells in vitro for subsequent implantation of the muscle cells into a subject to regenerate cardiac muscle.

23. A method of treating a muscle disorder, the method comprising administering to a subject in need thereof therapeutically effective amounts of 3, 7-dimethyl-6 (S),7(S) -methanone, 7- [1,1,4, 4-tetramethyl-1, 2,3, 4-tetrahydronaphthalen-7-yl ]2(E),4(E) heptadienoic acid, and thyroxine; and wherein administration of the combination reduces the severity of the muscle disease in the individual by slowing or stopping progression, and/or inducing or accelerating repair or regeneration of the affected muscle or muscle, wherein administration of the RXR agonist and thyroid hormone treats the muscle disease in the individual more effectively than the RXR agonist or thyroid hormone alone.