Link:  Pharm/Biotech Resources

Title:  Inhibitors of proteasomal activity for stimulating hair growth

United States Patent:  6,958,220

Issued:  October 25, 2005

Inventors:  Mundy; Gregory R. (San Antonio, TX); Garrett; I. Ross (San Antonio, TX); Rossini; Jorge G. (San Antonio, TX)

Assignee:  OsteoScreen, Inc. (San Antonio, TX)

Appl. No.:  050425

Filed:  January 15, 2002

This inventions relates to compounds that inhibit the activity of the proteasome and both promotes hair growth and stimulates the production of hair follicles. The compounds provided herein are thus useful in stimulating hair growth, including hair density, in subject where this is desirable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to compositions and methods for use in enhancing hair density and growth. More specifically, the invention concerns the use of inhibitors of proteasomal activity and inhibitors of NF-κB activity for this purpose.

2. Description of Related Art

Inhibitors of proteasomal activity, and to some extent inhibitors of NF-κB activity, have two important physiological effects. First, they are able to enhance bone formation and are thus useful for treating various bone disorders. Second, they stimulate the production of hair follicles and are thus useful in stimulating hair growth, including hair density, in subject where this is desirable. The present invention focuses on this latter function.

Disorders of human hair growth include male pattern baldness, alopecia areota, alopecia induced by cancer chemotherapy and hair thinning associated with aging. These conditions are poorly understood, but nevertheless common and distressing, since hair is an important factor in human social and sexual communication.

Hair follicle regulation and growth are still not well understood, but represent dynamic processes involving proliferation, differentiation and cellular interactions during tissue morphogenesis. It is believed that hair follicles are formed only in early stages of development and not replaced.

Hardy, M. H. et al. Trans Genet (1992) 8:55-61 describes evidence that bone morphogenetic proteins (BMPs), members of the TGFβ super family, are differentially expressed in hair follicles during development. Harris, S. E. et al. J Bone Miner Res (1994) 9:855-863 describes the effects of TGFβ on expression of BMP-2 and other substances in bone cells. BMP-2 expression in mature follicles also occurs during maturation and after the period of cell proliferation (Hardy et al. (1992, supra). As noted, however, by Blessing, M. et al. Genes and Develop (1992) 7:204-215, the precise role functional role of BMP-2 in hair follicle maturation remains unclear.

Approaches to treat baldness abound in the U.S. patent literature. See for example U.S. Pat. No. 5,767,152 (cyanocarboxylic acid derivatives), U.S. Pat. No. 5,824,643 (keratinocyte growth factors) and U.S. Pat. No. 5,910,497 (16-pyrazinyl-substitute-4-aza-androstane 5-alpha.-reductase isozyme 1 inhibitors). There are many others.

Gat, U. et al. Cell (1998) 95:605-614 has demonstrated that β-catenin causes adult epithelial cells to create hair follicles, a surprising result in light of the known inability of mature cells to do so. B-Catenin is known to play a role in cell-cell adhesion and growth factor signal transfection. It is also known that after ubiquitination, β-catenin is degraded by the proteasomes. Orford, K. et al. J Biol Chem (1997) 272:24735-24738. At least one gene associated with hair growth (or lack thereof) has also been reported. Ahmed, W. et al. Science (1998) 279:720-724.

Two accepted agents currently used for the treatment of hair loss are the antihypertensive drug Minoxidil and the 5α-reductase inhibitor Finasteride. Neither is entirely satisfactory. Both suffer from modest efficacy and are inconvenient to administer. A specific, topically active and easy to administer compound with better efficacy than these agents would represent a marked advance.

The present invention discloses convenient assays for compounds that will be useful in stimulating hair growth. The assays involve inhibition of the activity of the transcription factor NF-κB or of the activity of proteasomal proteases, preferably proteasomal proteases. Compounds which inhibit these activities are generally useful in treating hair growth disorders. Compounds that inhibit the production of the transcription factor and these proteases will also be useful in the invention. Their ability to do so can be further confirmed by additional assays.

The proteasome is a noncompartmentalized collection of unrelated proteases which form a common architecture in which proteolytic subunits are self-assembled to form barrel-shaped complexes (for review, see Baumeister et al., Cell (1998) 92:367-380. The proteasome contains an array of distinct proteolytic activities inside eukaryotic cells. Compounds which inhibit proteasomal activity also reduce NF-κB activity by limiting its capacity to be translocated to the nucleus (Barnes, P. J. et al. New Engl J Med (1997) 336:1066-1071.

BRIEF SUMMARY OF THE INVENTION

The present invention adds to the repertoire of osteogenic and hair growth stimulating agents by providing drugs which would inhibit key proteins and enzymes involved in proteasomal activity and which decrease the activity of the nuclear transcription factor NF-κB, and thus stimulate bone and hair growth. In accordance with the present invention, we have discovered that inhibition of the functions of the proteasomal proteins and the transcription factor NF-κB in bone cells leads to increased bone growth and to hair follicle formation and stimulation. Thus, assessing a candidate compound for its ability to inhibit proteasomal proteins or NF-κB provides a useful means to identify bone and hair growth anabolic agents.

The present specification thus provides methods for identification of osteogenic compounds to stimulate bone growth and compounds that stimulate hair growth by assessing their capacity to inhibit proteasome activity or to inhibit the activity of the transcription factor NF-κB, preferably to inhibit proteasomal activity. Also useful in the methods of the invention are compounds which inhibit the in situ production of the enzymes contained in the proteasome or inhibit the production of NF-κB, preferably of enzymes of the proteasomes. Once a compound found to inhibit these activities has been identified, it can be used in an additional aspect of the invention—a method to stimulate the growth of bone or of hair by contacting suitable cells with the identified compound. The cellular contact may include in vivo administration and the compounds of the invention are thus useful in treating degenerative bone diseases, fractures, dental problems, baldness, alopecia and the like. These methods are performed, according to the present invention, with compounds identified as inhibitors of proteasome activity or inhibitors of the activity of transcription factor NF-κB, preferably inhibitors of the proteasome enzymes, or inhibitors of the production of the proteasome enzymes or of NF-κB, preferably of the proteasome enzymes.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the present invention, there are provided methods of treating disorders of hair growth. Disorders of hair growth may be the result of a defect in the ability of existing hair follicles to extrude hair, or may be the result of a deficiency in the number of hair follicles per se. "Stimulation of hair growth" refers to increasing the volume of hair in a particular area of a subject whether this is the result of an increased rate of growth in length and/or thickness from the same number of hair follicles, growth proceeding from an enhanced number of hair follicles, or both. The number of hair follicles can be enhanced by further activating existing hair follicles or by stimulating the appearance or proliferation of hair follicles in a particular region of the skin.

As employed herein, the term "subject" embraces human as well as other animal species, such as, for example, canine, feline, bovine, porcine, rodent, and the like. It will be understood by the skilled practitioner that the subject is one appropriate to the desirability of stimulating bone growth or hair growth. Thus, in general, for example, stimulation of hair growth will be confined in most instances to animals that would appropriately exhibit such growth.

Conditions which would be benefited by "treating" or "treatment" for stimulation of hair growth include male pattern baldness, alopecia caused by chemotherapy, hair thinning resulting from aging, genetic disorders which result in deficiency of hair coverage, and, in animals, providing additional protection from cold temperatures. Thus, while use in humans may be primarily of cosmetic benefit, use in animals may be therapeutic as well.

The compositions of the invention may be administered systemically or locally. For systemic use, the compounds herein are formulated for parenteral (e.g., intravenous, subcutaneous, intramuscular, intraperitoneal, intranasal or transdermal) or enteral (e.g., oral or rectal) delivery according to conventional methods. Intravenous administration can be by a series of injections or by continuous infusion over an extended period. Administration by injection or other routes of discretely spaced administration can be performed at intervals ranging from weekly to once to three times daily. Alternatively, the compounds disclosed herein may be administered in a cyclical manner (administration of disclosed compound; followed by no administration; followed by administration of disclosed compound, and the like). Treatment will continue until the desired outcome is achieved. In general, pharmaceutical formulations will include a compound of the present invention in combination with a pharmaceutically acceptable vehicle, such as saline, buffered saline, 5% dextrose in water, borate-buffered saline containing trace metals or the like. Formulations may further include one or more excipients, preservatives, solubilizers, buffering agents, albumin to prevent protein loss on vial surfaces, lubricants, fillers, stabilizers, etc. Methods of formulation are well known in the art and are disclosed, for example, in Remington's Pharmaceutical Sciences, latest edition, Mack Publishing Co., Easton Pa., which is incorporated herein by reference. Pharmaceutical compositions for use within the present invention can be in the form of sterile, non-pyrogenic liquid solutions or suspensions, coated capsules, suppositories, lyophilized powders, transdermal patches or other forms known in the art. Local administration may be by injection at the site of injury or defect, or by insertion or attachment of a solid carrier at the site, or by direct, topical application of a viscous liquid, or the like. For local administration, the delivery vehicle preferably provides a matrix for the growing bone or cartilage, and more preferably is a vehicle that can be absorbed by the subject without adverse effects.

Delivery of compounds herein to wound sites may be enhanced by the use of controlled-release compositions, such as those described in PCT publication WO93/20859, which is incorporated herein by reference. Films of this type are particularly useful as coatings for prosthetic devices and surgical implants. The films may, for example, be wrapped around the outer surfaces of surgical screws, rods, pins, plates and the like. Implantable devices of this type are routinely used in orthopedic surgery. The films can also be used to coat bone filling materials, such as hydroxyapatite blocks, demineralized bone matrix plugs, collagen matrices and the like. In general, a film or device as described herein is applied to the bone at the fracture site. Application is generally by implantation into the bone or attachment to the surface using standard surgical procedures.

In addition to the copolymers and carriers noted above, the biodegradable films and matrices may include other active or inert components. Of particular interest are those agents that promote tissue growth or infiltration, such as growth factors. Exemplary growth factors for this purpose include epidermal growth factor (EGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), transforming growth factors (TGFs), parathyroid hormone (PTH), leukemia inhibitory factor (LIF), insulin-like growth factors (IGFs) and the like. Agents that promote bone growth, such as bone morphogenetic proteins (U.S. Pat. No. 4,761,471; PCT Publication WO90/11366), osteogenin (Sampath et al. Proc. Natl. Acad. Sci. USA (1987) 84:7109-13) and NaF (Tencer et al. J. Biomed. Mat. Res. (1989) 23:571-89) are also preferred. Biodegradable films or matrices include calcium sulfate, tricalcium phosphate, hydroxyapatite, polylactic acid, polyanhydrides, bone or dermal collagen, pure proteins, extracellular matrix components and the like and combinations thereof. Such biodegradable materials may be used in combination with non-biodegradable materials, to provide desired mechanical, cosmetic or tissue or matrix interface properties.

Alternative methods for delivery of compounds of the present invention include use of ALZET osmotic minipumps (Alza Corp., Palo Alto, Calif.); sustained release matrix materials such as those disclosed in Wang et al. (PCT Publication WO90/11366); electrically charged dextran beads, as disclosed in Bao et aL (PCT Publication WO92/03 125); collagen-based delivery systems, for example, as disclosed in Ksander et al. Ann. Surg. (1990) 211(3):288-94; methylcellulose gel systems, as disclosed in Beck et al. J. Bone Min. Res. (1991) 6(11):1257-65; alginate-based systems, as disclosed in Edelman et al. Biomaterials (1991) 12:619-26 and the like.

In additional formulations, conventional preparations such as those described below may be used.

Aqueous suspensions may contain the active ingredient in admixture with pharmacologically acceptable excipients, comprising suspending agents, such as methyl cellulose; and wetting agents, such as lecithin, lysolecithin or long-chain fatty alcohols. The said aqueous suspensions may also contain preservatives, coloring agents, flavoring agents, sweetening agents and the like in accordance with industry standards.

Preparations for topical and local application comprise aerosol sprays, lotions, gels and ointments in pharmaceutically appropriate vehicles which may comprise lower aliphatic alcohols, polyglycols such as glycerol, polyethylene glycol, esters of fatty acids, oils and fats, and silicones. The preparations may further comprise antioxidants, such as ascorbic acid or tocopherol, and preservatives, such as p-hydroxybenzoic acid esters.

Parenteral preparations comprise particularly sterile or sterilized products. Injectable compositions may be provided containing the active compound and any of the well known injectable carriers. These may contain salts for regulating the osmotic pressure.

If desired, the hair stimulating agents can be incorporated into liposomes by any of the reported methods of preparing liposomes for use in treating various pathogenic conditions. The present compositions may utilize the compounds noted above incorporated in liposomes in order to direct these compounds to macrophages, monocytes, as well as other cells and tissues and organs which take up the liposomal composition. The liposome-incorporated compounds of the invention can be utilized by parenteral administration, to allow for the efficacious use of lower doses of the compounds. Ligands may also be incorporated to further focus the specificity of the liposomes.

Suitable conventional methods of liposome preparation include, but are not limited to, those disclosed by Bangham, A. D. et al. J Mol Biol (1965) 23:238-252, Olson, F. et al. Biochim Biophys Acta (1979) 557:9-23, Szoka, F. et al. Proc Natl Acad Sci USA (1978) 75:4194-4198, Kim, S. et al. Biochim Biophys Acta (1983) 728:339:348, and Mayer, et al. Biochim Biophys Acta (1986) 858:161-168.

The liposomes may be made from the present compounds in combination with any of the conventional synthetic or natural phospholipid liposome materials including phospholipids from natural sources such as egg, plant or animal sources such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingomyelin, phosphatidylserine, or phosphatidylinositol and the like. Synthetic phospholipids that may also be used, include, but are not limited to: dimyristoylphosphatidylcholine, dioleoylphosphatidylcholine, dipalmitoylphosphatidylcholine and distearoylphosphatidycholine, and the corresponding synthetic phosphatidylethanolamines and phosphatidylglycerols. Cholesterol or other sterols, cholesterol hemisuccinate, glycolipids, cerebrosides, fatty acids, gangliosides, sphingolipids, 1,2-bis(oleoyloxy)-3-(trimethyl ammonio) propane (DOTAP), N-[1-(2,3-dioleoyl) propyl-N,N,N-trimethylamnmonium chloride (DOTMA), and other cationic lipids may be incorporated into the liposomes, as is known to those skilled in the art. The relative amounts of phospholipid and additives used in the liposomes may be varied if desired. The preferred ranges are from about 60 to 90 mole percent of the phospholipid; cholesterol, cholesterol hemisuccinate, fatty acids or cationic lipids may be used in amounts ranging from 0 to 50 mole percent. The amounts of the present compounds incorporated into the lipid layer of liposomes can be varied with the concentration of the lipids ranging from about 0.01 to about 50 mole percent.

The liposomes with the above formulations may be made still more specific for their intended targets with the incorporation of monoclonal antibodies or other ligands specific for a target. For example, monoclonal antibodies to the BMP receptor may be incorporated into the liposome by linkage to phosphatidylethanolamine (PE) incorporated into the liposome by the method of Lesernan, L. et al. Nature (1980) 288:602-604.

Veterinary uses of the disclosed compounds are also contemplated, as set forth above. Such uses would include treatment of defects associated with hair or fur in domestic animals, livestock and thoroughbred horses.

The compounds of the present invention may also be used to stimulate the growth of hair either by enhancing its rate of formation from existing follicles, stimulating inactive follicles, effecting the production of additional hair follicles or some combination of the foregoing, or by any other mechanism that may or may not presently be understood.

Within the present invention, an "effective amount" of a composition is that amount which produces a statistically significant effect. An "effective amount" for uses in stimulating hair growth is that amount which provides the desired effect in terms of length or density of hair. Such effective amounts will be determined using routine optimization techniques and are dependent on the particular condition to be treated, the condition of the patient, the route of administration, the formulation, and the judgment of the practitioner and other factors evident to those skilled in the art. General guidance for treatment regimens is obtained from experiments carried out in animal models of the disease of interest. Differences between successfully treated subjects and controls with regard to stimulation of hair growth can generally be ascertained by direct observation.

The dosage of the compounds of the invention will vary according to the extent and severity of the need for treatment, the activity of the administered compound, the general health of the subject, and other considerations well known to the skilled artisan. Generally, they can be administered to a typical human on a daily basis as an oral dose of about 0.1 mg/kg-1000 mg/kg, and more preferably from about 1 mg/kg to about 200 mg/kg. The parenteral dose will appropriately be 20-100% of the oral dose. While oral administration may be preferable in most instances where the condition is a bone deficit (for reasons of ease, patient acceptability, and the like), alternative methods of administration may be appropriate for selected compounds and selected defects or diseases. While topical administration is generally preferable for stimulating hair growth, as generally only local effects are desired, systemic treatment may be preferable in some instances as well.
 

Claim 1 of 8 Claims

1. A method to treat a mammalian subject for a condition benefited by stimulating hair growth which method comprises administering to said mammalian subject in need of such treatment an effective amount of a compound that inhibits proteasomal activity, wherein said compound is a peptidyl aldehyde or a peptidyl epoxy ketone.

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