WO2009091889A1 - Treatment of skin disorders with egfr inhibitors - Google Patents

Abstract

Methods and compositions for the treatment of skin disorders (e.g., genetic skin disorders) are provided. The methods and compositions include an EGFR inhibitor. For genetic skin disorders that exhibit a high percentage of penetrance, or complete penetrance, such as Darier's disease, the methods and compositions provided herein can be used to prevent or reduce manifestation of symptoms of the disease.

Description

TREATMENT OF SKIN DISORDERS WITH EGFR INHIBITORS

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 61/022,067, filed January 18, 2008, the entire disclosure of which is hereby incorporated by reference in its entirety.

BACKGROUND

Recent advances in molecular biology have elucidated well over two hundred skin disorders that occur at a genetic level. The vast majority of these disorders are characterized by a disorder in keratinization, usually an over-production of keratin (hyperkeratosis) and/or of the keratinocytes that produce keratin (keratinocyte hyperplasia). Hyperkeratosis is typified by dry, scaly skin, abnormal thickening of the epidermis, and rapid cell turnover in the skin.

Traditional therapies for hyperkeratosis disorders include topical and systemic steroids, antibiotics and topical and oral retinoids. To manage the disorders and keep the symptoms under control, these treatments need to be administered long term. The treatments however tend to be partially effective at best, resulting in some improvement of the manifested symptoms, but limited efficacy in long term use. In addition, retinoids, which are the most commonly used treatment as they tend to be the most efficacious, often cause undesirable side effects such as erythema (redness), scaling, burning, and/or pruritus (itching) and, in more extreme cases, bone toxicity, especially when they are used long term.

SUMMARY

The compositions, methods, combinations, kits and articles of manufacture provided below are characterized by a variety of component ingredients, steps in treatment, and biophysical, physical, biochemical or chemical parameters. As would be apparent to those of skill in the art, the compositions and methods provided herein include any and all permutations and combinations of the ingredients, steps and/or parameters described below. Provided herein are methods and compositions for treating genetic skin disorders, using one or more epidermal growth factor receptor (EGFR) inhibitors. The genetic skin disorders include keratinization disorders. The genetic skin disorders may be characterized by one or more features selected from among hyperkeratosis, keratinocyte hyperplasia, and ichthyosis.

Provided herein is a method of treating a monogenic inherited keratinization disorder by administering to a subject identified as having the disorder a therapeutically effective amount of an EGFR inhibitor. The EGFR inhibitor can be any compound that inhibits the signal transduction pathway triggered by EGFR, and the inhibition can occur at any step of the pathway. The EGFR inhibitor can be selected from among an antibody that binds to EGFR, an antisense nucleic acid, a tyrphostin, a quinazolone compound, a quinazoline compound, a quinazolinamine compound, a 2-phenylaminopyrimidine, a quinoxaline, a phenolic stibenoid, a tyrosine metabolite, a flavonoid, an isoflavonoid and methyl-2,5-dihydroxycinnamate. By way of example, the monogenic keratinization disorder treated using an EGFR inhibitor is Darier's disease.

Also provided herein is a method of treating a keratinization disorder by administering to a subject identified as having the keratinization disorder a therapeutically effective amount of an EGFR inhibitor, wherein the EGFR inhibitor is selected from among an antibody that binds to EGFR, an antisense nucleic acid, a quinoxaline, a phenolic stibenoid, a tyrosine metabolite, a flavonoid, an isoflavonoid and methy 1-2 , 5 -dihy droxy cinnamate .

Also provided herein are compositions, combinations, kits and articles of manufacture that include an EGFR inhibitor, or an EGFR inhibitor and an anticancer agent, for treating a genetic skin disorder. The article of manufacture optionally includes an EGFR inhibitor adjusted to a dosage suitable for the treatment of a monogenic keratinization disorder, and a carrier for topical administration. The articles of manufacture provided herein can further include a delivery system for the EGFR inhibitor. Also provided herein are compositions containing an EGFR inhibitor, an anticancer agent and a carrier selected for topical administration. DETAILED DESCRIPTION A. Treatment of Genetic Skin Disorders 1. Genetic Skin Disorders

Provided herein are compositions and methods for treating genetic skin disorders. Genetic skin disorders, or genodermatoses, represent a broad class of diseases affecting millions of people, worldwide. To date, over 300 skin conditions have been identified as having a genetic basis. Of these, about 170 disorders are believed to be associated with a single gene that can be inhereited in Mendelian fashion (monogenic diseases). Examples of monogenic skin diseases include disorders such as Darier's disease, Hailey-Hailey disease, erythrodermic autosomal recessive lamellar ichthyosis, nonerythrodermic autosomal recessive lamellar ichthyosis, autosomal dominant lamellar ichthyosis, bullous congenital ichthyosiform erythroderma, palmoplantar keratoderma, erythrokeratodermia variabilis, verrucous epidermal nevi, pityriasis rubra pilaris, Netherton syndrome, idiopathic vulgaris, ichthyosis vulgaris, monilethrix, keratosis piliaris, bullous ichthyosiform erythroderma, nonbullous congenital ichthyosis, Sjogreen-Larsson syndrome, erythrokeratodermica variabilis, hyperkeratosis lenticularis perstans, eythrokeratodermia fϊgurate variabilis, mutilating keratoderma of Vohwinkel, Harlequin ichthyosis and Tay's syndrome. Over 100 other genetic skin disorders are polygenic, which are disorders that are correlated to multiple causative genes.

Mutations or other defects in any one of the multiple genes may only have minor effects on disease susceptibility; occurrence of the disease usually involes a complex interplay among the causative genes. In addition, many polygenic genodermatoses are complex diseases requiring interaction of the genetic components with the environment, lifestyle, race, immune system, and other such factors. Examples of polygenic genodermatoses include a spectrum of psoriasis and psoriatic arthritis disorders, vitiligo, alopecia areata, systemic lupus erythematosus, and atopic dermatitis. A comprehensive list of genetic skin disorders, and their associated genes, is set forth in Leech et ah, Br. J. Dermatol, 156:1115-1148 (2007), the contents of which are incorporated by reference herein. The treatment of any of these disorders is contemplated according to the methods provided herein, and using EGFR inhibitors and compositions thereof as provided herein. A vast majority of genetic skin disorders are characterized by disorders in keratinization; these include mutations in keratin genes, over-production of keratin (hyperkeratosis) and/or keratinocyte hyperplasia. Since the late 1980's, and especially in the last ten years, progress in the Human Genome Project and advances in genetic technology have led to the mapping and cloning of the causative genes of many monogenic genodermatoses, the susceptibility genes of many polygenic genodermatoses, and the genotype-phenotype correlation associated with expression and manifestation of these genes.

In 1987, the first human skin disorder gene was identified, the steroid sulfatase (STS) gene on the X-chromosome 9. The entire STS gene is completely deleted in many males with X-linked ichthyosis, allowing its identification by early molecular genetics techniques. In the late 1980s and early 1990s, mutations in human keratin genes were linked to a variety of genetic skin disorders (McLean et ah, Ulster Med. J, 76(2):72-82 (2007)). For example, mutations in ketain 5 or keratin 14 have been linked to epidermolysis bullosa simplex (EBS) disorders, and mutations in keratin 1 or keratin 10 have been linked to epidermolytic hyperkeratosis. Like epidermolytic hyperkeratosis, there are a variety of other skin disorders, described and incorporated by reference herein, which are associated with hyperkeratosis; several of these other disorders, however, are caused by genes other than the keratin genes. For example, Darier's disease and Hailey-Hailey disease, are autosomal dominant disorders caused by mutations in an ATPase, and recessive lamellar ichtyosis is an autosomal recessive disorder caused by keratinocyte transglutaminase.

Darier's disease Among the methods and compositions provided herein for the treatment of genetic skin disorders, are methods and compositions for treating Darier's disease.

The methods and compositions employ EGFR inhibitors that can inhibit any step of the EGFR-mediated signal transduction pathway.

Darier's disease is a genetic hyperkeratosis skin disorder characterized by dark crusty patches on the skin, sometimes containing pus. The crusty patches are also known as keratotic papules and also called keratosis follicularis . Darier's disease is an autosomally dominant inherited mutation in the gene ATP2A2, encoding SERCA2 (sarco/endoplasmic reticulum Ca2+-transport ATPase isoform 2). A related genetic skin disorder characterized by hyperkeratosis is Hailey-Hailey disease, in which the ATP2C 1 (the gene encoding the human secretory pathway Ca2+/Mn2+ ATPase (hSPCAl)) is identified as the pathogenic gene that is transmitted in an autosomal dominant fashion. The incidence of the two disorders is similar, 1 :25, 000-1 : 100,000 for Darier's disease, and 1 :50,000 for Hailey-Hailey disease. The penetrance of both these disorders is complete (i.e., all subjects having one mutated allele manifest the symptoms), but expressivity varies significantly among subjects afflicted with the disease. For example, family members with confirmed identical ATP2A2 mutations can exhibit differences in the clinical severity of disease, suggesting that other genes or environmental factors affect the expression of Darier's disease. With the discovery of the ATP2A2 gene, performing genetic tests to confirm the diagnosis of Darier's disease is now possible.

Darier's disease often starts during or later than the teenage years, typically by the third decade. The symptoms of the disease are thought to be caused by an abnormality in the desmosome-keratin filament complex leading to a breakdown in cell adhesion. The disease most commonly affects the chest, neck, back, ears, forehead, and groin, but may involve other body areas. The rash associated with Darier's disease often has a distinct odor, and can be aggravated by heat, humidity, and exposure to sunlight. Hence, like other genetic skin disorders, it is a disease that poses a significant burden to afflicted persons.

To date, the treatment of choice for Darier's disease has been oral retinoids, such as ACCUTANE® (Hoffman-La Roche, Nutley, New Jersey) (13-cώ-retinoic acid) and SORIATANE® (Hoffman-La Roche, Nutley, New Jersey; all-trans-9-(4- methoxy-2,3,6-trimethylphenyl)-3,7-dimethyl-2,4,6,8-nonatetraenoic acid). In addition, during flares, topical or oral antibiotics may be administered. Cyclosporin and topical corticosteroids have been used during acute flares. Some patients are able to prevent flares with use of topical sunscreens and oral vitamin C. These treatments, however, show moderate and very short-term effectiveness in ameliorating symptoms, such as the severity of skin lesions. Besides, the tolerance to oral retinoids is poor in the long-term.

Provided herein are improved methods and compositions for preventing or treating manifestations of Darier's disease, which use an EGFR inhibitor. As described and exemplified herein, the EGFR inhibitors, such as the antibody ERBITUX® (ImClone, New York, New York; also known as cetuximab) and the quinazolone compound erlotinib, are less toxic and better tolerated than the retionoids. In addition, the EGFR inhibitors produce a dramatic reduction in skin lesions and other physical manifestations of Darier's disease, relative to the retinoids.

The methods can be used to treat Darier's disease or, because of its penetrance at 100%, for reducing the probability of appearance of symptoms prophylactically, prior to their manifestation in a subject identified as carrying the mutant ATP2A2 allele. 2. EGFR Inhibitors The methods and compositions provided herein for the treatment of genetic skin disorders employ the use of EGFR inhibitors. The EGFR inhibitors provided herein can reduce the severity of symptoms/ manifestations of the genetic skin disorders, without triggering unwanted effects. a. Receptor Tyrosine Kinases The epidermal growth factor receptor (EGFR) belongs to a family of proteins known as receptor tyrosine kinases (RTKs). RTKs have a conserved domain structure including an extracellular domain, a membrane-spanning (transmembrane) domain and an intracellular tyrosine kinase domain. The extracellular domain can bind a ligand, such as a polypeptide growth factor or a cell membrane-associated molecule. Some RTKs have been classified as orphan receptors, having no identified ligand.

Some RTKs are classified as constitutive RTKs, active without ligand binding, for example ErbB2 (HER2) does not reqire a ligand for activity.

Typically, dimerization of RTKs activates the catalytic tyrosine kinase domain of the receptor and subsequent activities in signal transduction. RTKs can be homodimers or heterodimers. For example, PDGF is a heterodimer composed of α and β subunits. VEGF receptors are homodimers. EGF receptors can be either heterodimers or homodimers. In another example, erbB3, in the presence of the ligand heregulin, heterodimerizes with other members of the ErbB family (EGFR family) such as ErbB2 and ErbB3. Many RTKs are capable of autophosphorylation when dimerized, such as by transphosphorylation between subunits.

Autophosphorylation in the kinase domain maintains the tyrosine kinase domain in an activated state. Autophosphorylation in other regions of the protein can influence interaction of the receptor with other cellular proteins.

RTKs interact in signal transduction pathways. For example, RTKs, when activated, can phosphorylate other signaling molecules. RTKs are closely associated with cell growth, proliferation, differentiation and signaling of the immune system.

The receptor tyrosine kinases participate in transmembrane signaling, whereas the intracellular tyrosine kinases take part in signal transduction within the cell. For example, EGFR interacts in signal transduction pathways involved in processes including proliferation, dedifferentiation, apoptosis, cell migration and angiogenesis. EGFR family members can recruit signaling molecules through protein:protein interactions; some interactions involve specific binding of signaling molecules to tyrosine phosphorylated sites on the receptor. For example, the Grb2/Sos complex can bind to phosphotyrosine sites on EGFR, in turn activating the Ras/Raf/MAPK signaling cascade, which influences cell proliferation, migration and differentiation. Other exemplary signally molecules include other RTKs, G-coupled receptors, integrins, phospholipase C, Ca2+/calmodulin-dependent kinases, transcriptional activators, cytokines and other kinases.

Because of the topology of receptor tyrosine kinases, the ligand binding domain and the protein kinase activity are separated by the plasma membrane. Signal transduction across the membrane involves receptor dimerization followed by the ligand-induced conformational changes in the extracellular domain. Uncontrolled signaling from receptor tyrosine kinases and intracellular tyrosine kinases can lead to numerous diseases. Over 80% of the oncogenes and protooncogenes involved in human cancers code for RTKs. The enhanced activity of RTKs is also implicated in many nonmalignant diseases, such as psoriasis, papilloma, restenosis, and pulmonary fibrosis. RTKs have also been associated with inflammatory conditions. b. EGFR EGFR is a 170 kDa protein that binds to EGF, a small, 53 amino acid protein- ligand that stimulates the proliferation of epidermal cells and a wide variety of other cell types. EGF receptors are widely expressed in epithelial, mesenchymal and neuronal tissues and play important roles in proliferation and differentiation. EGF receptors are encoded by a family of related genes known also as erbB genes (e.g. erbB2, erbB3, erbB4) and HER genes (e.g. Her-2). The EGF receptor family includes four members, EGF -receptor (HER-I; erbB-1), human epidermal growth factor receptor-2 (HER-2; erbB-2), HER-3 (erbB-3) and HER-4 (erbB-4). The ligand for EGFR/HER- 1 is EGF, while the ligand for HER-2, HER-3 and HER-4 is neuregulin- 1

(NRG-I). NRG-I preferentially binds to either HER-3 or HER-4 after which the bound receptor subunit heterodimerizes with HER-2. HER-4 also is capable of homodimerization to form an active receptor.

Binding of a ligand to the extracellular domain of the EGFR leads to receptor dimerization, activating the tyrosine-kinase activity in the cytoplasmic portion of the molecule and triggering a signaling cascade leading to cellular proliferation. Tyrosine kinase inhibitors from the tyrphostin family were found to block EGF-dependent cell proliferation in psoriatic, HPV 16 immortalized and normal keratinocytes.

The epidermal growth factor receptor has multiple roles in epidermal biology relating to growth, migration and survival of keratinocytes. In addition, overexpression of the EGF receptor (EGFR) kinase is the hallmark of most if not all epithelial cancers. Furthermore, in most epithelial tumors, other members of the EGFR family are co-expressed, enabling also the formation of heterodimers necessary for activation of the kinase. For example, the TGF-α/EGFR system activates in an autocrine manner epidermal keratinocyte proliferation.

Misregulation of the ErbB family has been implicated in a number of different types of cancer. For example, overexpression of EGFR is associated with a number of human tumors including, but not limited to, esophageal, stomach, bladder and colon cancers, gliomas and meningiomas, squamous carcinoma of the lungs, and ovarian, cervical and renal carcinomas, squamous cell carcinoma, colorectal cancer, lung cancer, breast cancer, laryngeal cancer, hypopharyngeal cancer, pancreatic cancer, ovarian cancer, gastric cancer and prostate cancer. Overexpression of EGFR is also believed to be associated with other pathological conditions of the skin including psoriasis, keratinocyte proliferation and skin lesions caused or induced by Papilloma virus infection, seborrheic keratoses, acanthosis nigricans, ichthyosis (e.g. ichthyosis vulgaris and congenital ichthyoses), keratodermias, genodermatoses with pathological cornifϊcation disorders (e.g. Darier's disease), further lichen ruber planus, pityriasis rubra pilaris, and skin cancers such as basal cell carcinoma, squamous cell carcinoma and melanoma. c. EGFR Inhibitors

A wide variety of classes of compounds are known to inhibit EGFR. The inhibitors can act at any step of the EGFR signal transduction pathway. For example, monoclonal antibodies to EGFR inhibit EGFR by preventing the binding of ligands to the receptor binding site. Other classes of compounds, such as the quinazolone compounds, act by blocking autophosphorylation (tyrosine kinase activity of EGFR). Any EGFR inhibitor already known to those of skill in the art, or identified by the assays provided herein, can be used in the methods and compositions for treating genetic skin disorders that are provided herein.

Biological agents that target the EGFR are at the forefront of novel anticancer therapies. For example, EGFR is highly expressed in patients with advanced gastric cancer and esophageal cancer. There are several potential strategies to target the EGFR. However, monoclonal antibodies (mAbs) and the low molecular weight tyrosine kinase inhibitors (TKIs) are the most developed ones and have reached the clinical scenario. A comprehensive review of known EGFR inhibitors that are used as anticancer treatments is provided in Mendelsohn, J. Clin. Oncol., 20, No. 18S, ls-13s (2002), the contents of which are incorporated by reference herein. Exemplary cancers that can be treated using EGFR inhibitors include non small cell lung carcinoma, colorectal cancer, squamous cell carcinoma, head and neck cancer, prostate cancer, ovarian cancer and breast cancer.

Exemplary EGFR inhibitors include, but are not limited to, natural inhibitors such as genistein, genistin, quercetin, equol, staurosporine, aeroplysinin, indocarbazole, lavendustin, piceatannol, kaempferol, daidzein, erbstatin, isoflavones, and tyrphostins.

Other representative EGFR inhibitors include AG-494 (a member of the tyrphostin family of tyrosine kinase inhibitors), AG-825 (5-[(Benzthiazol-2- yl)thiomethyl]-4-hydroxy-3-methoxybenzylidenecyanoaceta mide), AG-1478 (4-(3- Chloroanilino)-6,7-dimethoxyquinazoline) and 4-aniloquinazoline derivatives (W. A.

Denny, "The 4-anilinoquinazoline class of inhibitors of the erbB family of receptor tyrosine kinases," Farmaco 2001 January-February;56(l-2):51-6, discussing both reversibly and irreversibly binding analogs), EI-146 (an Erbstatin analog), methyl-2,5- dihydroxycinnamate, HDBA (2-Hydroxy-5-(2,5-dihydroxybenzylamino)-2- hydroxybenzoic acid; Onoda et al, J. Natural Products, 52:1252, 1989), Lavendustin A, RG-13022 (a non-phenolic tyrphostin analog which inhibits the EGFR), RG-14620 (a non-phenolic tyrphostin analog which is selective for the EGFR and long acting),

Tyrphostin 23 (RG-50810), Tyrphostin 25 ([(3 ,4,5-trihydroxyphenyl)-methylene]- propanedinitrile, Gazit et al., J. Med. Chem., 32:2344, 1989; also known as RG- 50875), Tyrphostin 46, Tyrphostin 47 (also known as RG-50864 and AG-213), Tyrphostin 51 , and Tyrphostin 1. A review article by S. B. Noonberg and C. C. Benz ("Tyrosine Kinase inhibitors Targeted to the Epidermal Growth Factor Receptor Subfamily—Role as Anticancer Agents", Drugs, 2000 Apr:59(4) (the disclosure of which is incorporated herein by reference)) describes various approaches for inhibiting the kinase activity of EGF receptors, including antibodies, immunotoxin conjugates, ligand-binding cytotoxic agents, and small molecule kinase inhibitors.

Small nucleotide inhibitors have also been developed for inhibiting EGFR, as well as for such kinases as JNK, MEKK, and others that activate EGFR signalling. Exemplary U.S. Pat. Nos. include 5,914,269 and 6,187,585 for EGFR inhibition, 5,877,309, 6,133,246, and 6,221,850 for JNK inhibition, 6,168,950 for MEKK inhibition, and other such as 6,054,440, 6,159,697, and 6,262,241 (the disicosures of which are all incorporated herein by reference). Antisense compounds that inhibit EGFR are described in U.S. Pat. Nos. 5,914,269 and 6,187,585.

A variety of other EGFR inhibitors are described in U.S. Patent Nos. 6,638,543; 6,004,967; and 7,247,301; and U.S. published Application Nos. US20060263349 Al and US20070282276 Al, the contents of each of which are incorporated in their entirety by reference herein. Exemplary of these are the following:

Examples of antibodies which bind to EGFR include cetuximab, panitumumab, zalutumumab, nimotuzumab, matuzumab, trastuzumab, ABX-EGF and Mab ICR-62, MAb 579 (ATCC CRL HB 8506), MAb 455 (ATCC CRL HB8507),

MAb 225 (ATCC CRL 8508), MAb 528 (ATCC CRL 8509) (see, U.S. Pat. No. 4,943,533, Mendelsohn et al.) and variants thereof, such as chimerized 225 (C225 or Cetuximab; ERBITUX® (ImClone, New York, New York) and reshaped human 225 (H225) (see, WO 96/40210, Imclone Systems Inc.); IMC-11F8, a fully human, EGFR-targeted antibody (Imclone); antibodies that bind type II mutant EGFR (U.S. Pat. No. 5,212,290); humanized and chimeric antibodies that bind EGFR as described in U.S. Pat. No. 5,891,996; and human antibodies that bind EGFR, such as ABX-EGF or Panitumumab (see WO98/50433, Abgenix/Amgen); EMD 55900 (Stragliotto et al. Eur. J. Cancer 32A:636-640 (1996)); EMD7200 (matuzumab) a humanized EGFR antibody directed against EGFR that competes with both EGF and TGF-alpha for EGFR binding (EMD/Merck); human EGFR antibody, HuMax-EGFR (GenMab); fully human antibodies known as El.1, E2.4, E2.5, E6.2, E6.4, E2.11, E6.3 and E7.6.3 and described in U.S. Pat. No. 6,235,883; MDX-447 (Medarex Inc); and mAb 806 or humanized mAb 806 (Johns et al., J. Biol. Chem. 279(29):30375-30384 (2004)). The anti-EGFR antibody may be conjugated with a cytotoxic agent, thus generating an immunoconjugate (see, e.g., EP659,439A2, Merck Patent GmbH). EGFR antagonists include small molecules such as compounds described in

U.S. Pat. Nos. 5,616,582, 5,457,105, 5,475,001, 5,654,307, 5,679,683, 6,084,095, 6,265,410, 6,455,534, 6,521,620, 6,596,726, 6,713,484, 5,770,599, 6,140,332, 5,866,572, 6,399,602, 6,344,459, 6,602,863, 6,391,874, 6,344,455, 5,760,041, 6,002,008, and 5,747,498, as well as the following PCT publications: WO98/14451, WO98/50038, WO99/09016, and WO99/24037. Particular small molecule EGFR antagonists include OSI-774 (CP-358774, TARCEVA® (erlotinib; OSI Pharmaceuticals, Melville, NY); PD 183805 (CI 1033, 2-propenamide, N-[4-[(3- chloro-4-fluorophenyl)amino]-7-[3-(4-morpholinyl)propoxy]-6-quin- azolinyl]-, dihydrochloride, Pfizer Inc.); ZD 1839, gefitinib (IRESSA™) 4-(3'-Chloro-4'- fluoroanilino)-7-methoxy-6-(3-morpholinopropoxy)quinazoli- ne, AstraZeneca); ZM

105180 ((6-amino-4-(3-methylphenyl-amino)-quinazoline, Zeneca); BIBX-1382 (N- 8-(3-chloro-4-fluoro-phenyl)-N-2-(l-methyl-piperidin-4-yl)-pyrimido[5,- A- d]pyrimidine-2,8-diamine, Boehringer Ingelheim); PKI-166 ((R)-4-[4-[(l- phenylethyl)amino]-lH-pyrrolo[2,3-d]pyrimidin-6-yl]-phenol)- ; (R)-6-(4- hydroxyphenyl)-4-[(l-phenylethyl)amino]-7H-pyrrolo[2,3-d]pyrimi- dine); CL-

387785 (N-[4-[(3-bromophenyl)amino]-6-quinazolinyl]-2-butynamide); EKB-569 (N- [4-[(3-chloro-4-fluorophenyl)amino]-3-cyano-7-ethoxy-6-quinolinyl]-4-(- dimethylamino)-2-butenamide) (Wyeth); AG1478 (Sugen); AG1571 (SU 5271; Sugen); dual EGFR/HER2 tyrosine kinase inhibitors such as lapatinib (GW 572016 or N-[3-chloro-4-[(3 fluorophenyl)methoxy]phenyl]6[5 [[[2methylsulfonyl)ethyl]amino]methyl]-2-furanyl]-4-quinazolinamine; GlaxoSmithKline).

Other tyrosine kinase inhibitors include small molecule HER2 tyrosine kinase inhibitors such as TAKl 65 available from Takeda; CP-724,714, an oral selective inhibitor of the ErbB2 receptor tyrosine kinase (Pfizer and OSI); dual-HER inhibitors such as EKB-569 (available from Wyeth) which preferentially binds EGFR but inhibits both HER2 and EGFR-overexpressing cells; lapatinib (GW572016; available from GlaxoSmithKline) an oral HER2 and EGFR tyrosine kinase inhibitor; PKI- 166 (available from Novartis); pan-HER inhibitors such as canertinib (CI- 1033; Pharmacia); Raf-1 inhibitors such as antisense agent ISIS-5132 available from ISIS Pharmaceuticals which inhibits Raf-1 signaling; non-HER targeted TK inhibitors such as Imatinib mesylate (GLEEVEC™, Novartis, Basel, Switzerland;) MAPK extracellular regulated kinase I inhibitor CI- 1040 (available from Pharmacia); quinazolines, such as PD 153035, 4-(3-chloroanilino) quinazoline; pyridopyrimidines; pyrimidopyrimidines; pyrrolopyrimidines, such as CGP 59326, CGP 60261 and CGP 62706; pyrazolopyrimidines, 4-(phenylamino)-7H-pyrrolo[2,3-d]pyrimidines; curcumin (diferuloyl methane, 4,5-bis(4-fluoroanilino)phthalimide); tyrphostines containing nitrothiophene moieties; PD-0183805 (Warner-Lamber); antisense molecules (e.g. those that bind to HER-encoding nucleic acid); quinoxalines (U.S. Pat. No. 5,804,396); tryphostins (U.S. Pat. No. 5,804,396); ZD6474 (Astra Zeneca); PTK-787 (Novartis/Schering AG); pan-HER inhibitors such as CI-1033 (Pfizer); Affmitac (ISIS 3521; Isis/Lilly); PKI 166 (Novartis); GW2016 (GlaxoSmithKline);

CI-1033 (Pfizer); EKB-569 (Wyeth); Semaxinib (Sugen); ZD6474 (AstraZeneca); PTK-787 (Novartis/Schering AG); INC-ICl 1 (Imclone); or as described in any of the following patent publications: U.S. Pat. No. 5,804,396; WO99/09016 (American Cyanamid); WO98/43960 (American Cyanamid); WO97/38983 (Warner Lambert); WO99/06378 (Warner Lambert); WO99/06396 (Warner Lambert); WO96/30347

(Pfizer, Inc); WO96/33978 (Zeneca); WO96/3397 (Zeneca); and WO96/33980 (Zeneca). Other small molecule EGFR inhibitors include 4-[(3-chloro-4- fluorophenyl)amino]-6- {[4-(morpholin-4-yl)- 1 -oxo-2-buten- 1 - -yljamino} -7- cyclopropylmethoxy-quinazoline, 4-[(R)-(I -phenyl-ethyl)amino]-6-{[4-(morpholin-4- yl)-l -oxo-2-buten- 1-yl] a- mino}-7-cyclopentyloxy-quinazoline, 4-[(3-chloro-4- fluorophenyl)amino]-6- { [4-((R)-6-methyl-2-oxo-morpholin-4~ yl)- 1 -oxo-2-buten- 1 - yljamino} -7- [(S)-(tetrahydrofuran-3-yl)oxy]-quinazolin- e, 4-[(3-chloro-4-fluoro- phenyl)amino]-6-[2-((S)-6-methyl-2-oxo-morphlin-4- -yl)ethoxy]-7-methoxy- quinazoline, 4-[(3-chloro-4-fluorophenyl)amino]-6-({4-[N-(2-methoxy-ethyl)-N- methyl-amino] - 1 -oxo-2-buten- 1 -yl} amino)-7-cyclopropylmethoxy-quinazoline, 4- [(R)-( 1 -phenyl-ethyl)amino] -6-( {4-[N-(tetrahydropyran-4-yl)-N-methy 1-am- ino] - 1 - oxo-2-buten- l-yl}amino)-7-cyclopropylmethoxy-quinazo line, 4-[(3-chloro-4-fluoro- phenyl)amino]-6-( {4-[N-(2-methoxy-ethyl)-N-methyl-a- mino]- 1 -oxo-2-buten- 1 - yl}amino)-7-cyclopentyloxy-quinazoline, 4-[(3-chloro-4-fluorophenyl)amino]-6-{[4- (N,N-dimethylamino)- 1 -oxo-2-bute- n- 1 -yl] amino } -7- [(R)-(tetrahydrofuran-2- yl)methoxy]-quinazoline, 4-[(3-ethinyl-phenyl)amino]-6,7-bis-(2-methoxy-ethoxy)- quinazoline, 4-[(R)-(I -phenyl-ethyl)amino]-6-(4-hydroxy-phenyl)-7H-pyrrolo[2, 3- d]pyrim- idine, 3-cyano-4-[(3-chloro-4-fluorophenyl)amino]-6- { [4-(N₅N- dimethylamino- )- 1 -oxo-2-buten- 1 -yl] amino } -7-ethoxy-quinoline, 4- [(R)-( 1 -phenyl- ethyl)amino]-6- { [4-((R)-6-methyl-2-oxo-morpholin-4-yl)- 1 - -oxo-2-buten- 1 - yl] amino }-7-methoxy-quinazo line, 4-[(3-chloro-4-fluoro-phenyl)amino]-6-{[4-

(morpholin-4-yl)-l -oxo-2-buten-- 1 -yljamino} -7-[(tetrahydrofuran-2-yl)methoxy]- quinazoline, 4-[(3-ethinyl-phenyl)amino]-6-{[4-(5,5-dimethyl-2-oxo-morpholin-4-yl)- 1 -o- xo-2-buten- 1 -yl]amino} -quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6- {2- [4-(2-oxo-morpholin-4-yl)-piperi- din- 1 -yl]-ethoxy} -7-methoxy-quinazoline, 4-[(3- chloro-4-fluoro-phenyl)amino]-6-(trans-4-amino-cyclohexan- 1 -yloxy)-- 7-methoxy- quinazoline, 4- [(3 -chloro-4-fluoro-phenyl)amino] -6-(trans-4-methanesulfonylamino- cyclo- hexan- 1 -yloxy)-7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]- 6-(tetrahydropyran-3 -yloxy)-7-methoxy- -quinazoline, 4- [(3 -chloro-4- fluorophenyl)amino]-6- { 1 -[(morpholin-4-yl)carbonyl]-piperi- din-4-yloxy} -7- methoxy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6-(piperidin-3-yloxy)-7- methoxy-quina- zoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6-[ 1 -(2-acetylamino- ethyl)-pip- eridin-4-yloxy] -7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro- phenyl)amino]-6-(tetrahydropyran-4-yloxy)-7-ethoxy~ quinazoline, 4-[(3-chloro-4- fluoro-phenyl)amino]-6-{trans-4-[(morpholin-4-yl)carbonyla- mino]-cyclohexan-l- yloxy} -7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6- { 1 -[piperidin- 1 -yl)carbonyl]-piperi- din-4-yloxy} -7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro- phenyl)-amino]-6-(cis-4-4- {N-[(morpholin-4-yl)carbo- nyl]-N-methyl-amino} -cyclo- hexan- 1 -yloxy)-7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6- (trans-4-ethanesulfonylamino-cycloh- exan- 1 -yloxy)-7-methoxy-quinazoline, 4-[(3- chloro-4-fluoro-phenyl)amino]-6-(l-methanesulfonyl-piperidin-4-ylox- y)-7-(2- methoxy-ethoxy)-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6-[ 1 -(2-methoxy- acetyl)-piperidin-4-y- loxy]-7-(2-methoxy-ethoxy)-quinazoline, 4-[(3-ethinyl- phenyl)amino]-6-(tetrahydropyran-4-yloxy] -7-methoxy-quinazo- line, 4- [(3 -chloro-4- fluoro-phenyl)amino] -6-(cis-4- (N- [(piperidin- 1 -yl)car- bonyl] -N-methyl-amino } - cyclohexan-l-yloxy)-7-methoxy-quinaozline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6- {cis-4-[(morpholin-4-yl)carbonylami- no]-cyclohexan-l-yloxy}-7-methoxy- quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6- { 1 -[2-(2-oxopyrrolidin-l - yl)ethyl]~ piperidin-4-yloxy} -7-methoxy-quinazoline, 4-[(3-ethinyl-phenyl)amino]-6- (l-acetyl-piperidin-4-yloxy)-7-methoxy-quin- azoline, 4-[(3-ethinyl-phenyl)amino]-6- ( 1 -methyl-piperidin-4-yloxy)-7-meth- oxy-quinazoline, 4- [(3 -ethinyl-phenyl)amino] - 6-(l -methanesulfonyl-piperidin-4-yloxy)-7-met- hoxy-quinazoline, 4-[(3-chloro-4- fluoro-phenyl)amino]-6-(l -methyl-piperidin-4-yloxy)-7-(2-m- ethoxy-ethoxy)- quinazoline, 4- [(3 -ethinyl-phenyl)amino] -6- { 1 - [(morpholin-4-yl)carbonyl] -piperidin- 4-y- loxy} -7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6- { 1 -[(N- methyl-N-2-methoxyethyl-amin- o)carbonyl]-piperidin-4-yloxy)-7-methoxy- quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6-(l-ethyl-piperidin-4-yloxy)-7- metho- xy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6[cis-4-(N- methanesulfonyl-N-methyl-a- mino)-cyclohexan- 1 -yloxy]-7-methoxy-quinazoline, 4- [(3-chloro-4-fluoro-phenyl)amino]-6-[cis-4-(N-acetyl-N-methyl-amino)-cy- clohexan- l-yloxy]-7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]6-(trans-4- methylamino-cyclohexan- 1 -yl- oxy)-7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro- phenyl)amino]-6-[trans-4-(N-methanesulfonyl-N-methy- l-amino)-cyclohexan- yloxy] -7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6-(trans-4- dimethylamino-cyclohexan- 1 - -yloxy)-7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro- phenyl)amino]-6-(trans-4- {N-[(morpholin-4-yl)carbon- yl]-N-methyl-amino} - cyclohexan-l-yloxy)-7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6- [2-(2,2-dimethyl-6-oxo-morpholin-4~ yl)-ethoxy]-7-[(S)-(tetrahydrofuran-2- yl)methoxy] -quinazoline, 4- [(3 -chloro-4-fluorophenyl)amino]-6-( 1 -methanesulfonyl- piperidin-4-yloxy- )-7-methoxy-quinazoline, 4-[(3-chloro-4-fluoro-phenyl)amino]-6-

(l-cyano-piperidin-4-yloxy)-7-metho- xy-quinazoline, and 4-[(3-chloro-4-fluoro- phenyl)amino]-6- { 1 -[(2-methoxyethyl)carbonyl]-piper- idin-4-yloxy } -7-methoxy- quinazoline, optionally in the form of their racemates, enantiomers or diastereomers, optionally in the form of their pharmacologically compatible acid addition salts, their solvates and/or hydrates.

Any of the above-mentioned EGFR inhibitors, or EGFR inhibitors identified as inhibiting any step of the EGFR-mediated signal transduction pathway, are contemplated for use in the methods and compositions provided herein.

3. Cancers and Skin Disease As discussed above, EGFR over-expression is associated with a number of cancers, including several that are of epithelial origin. Therefore, patients susceptible to such cancers often have associated genetic skin disorders. Accordingly, provided herein are methods and compositions for treating cancer patients having a genetic skin disorder, by administering an EGFR inhibitor to treat the skin disorder. The methods and compositions can include additional agents to treat the cancer. Such agents can include an EGFR inhibitor that is different from the inhibitor that is used to treat the skin disorder, radiation treatment, and a variety of other antineoplastic agents including, but not limited to:

Irinotecan, cisplatin, carboplatin, oxaliplatin, 5-fluorouracil, leucovorin; Alkylating agents, such as Alkyl sulfonates such as Busulfan, Improsulfan and

Piposulfan;

Aziridines such as Benzodepa, Carboquone, Meturedepa and Uredepa; Ethylenimines and methylmelamines such as Altretamine,

Triethylenemelamine, Triethylenephosphoramide, Triethylenethiophosphoramide and Trimethylolomelamine;

Nitrogen mustards such as Chlorambucil, Chlornaphazine, Chclophosphamide, Estramustine, Ifosfamide, Mechlorethamine, Mechlorethamine Oxide Hydrochloride, Melphalan, Novembichin, Phenesterine, Prednimustine, Trofosfamide and Uracil Mustard;

Nitrosoureas such as Carmustine, Chlorozotocin, Fotemustine, Lomustine, Nimustine and Ranimustine; and others such as Camptothecin, Dacarbazine, Mannomustine, Mitobronitol, Mitolactol and Pipobroman;

Antibiotics such as Aclacinomycins, Actinomycin Fl, Anthramycin, Azaserine, Bleomycins, Cactinomycin, Carubicin, Carzinophilin, Chromomycins, Dactinomycin, Daunorubicin, 6-Diazo-5-oxo-L-norleucine, Doxorubicin, Epirubicin, Mitomycins, Mycophenolic Acid, Nogalamycin, Olivomycins, Peplomycin, Plicamycin, Porfiromycin, Puromycin, Streptonigrin, Streptozocin, Tubercidin,

Ubenimex, Zinostatin and Zorubicin;

Antimetabolites, including: Folic acid analogs such as Denopterin, Methotrexate, Pteropterin and Trimetrexate;

Purine analogs such as Fludarabine, 6-Mercaptopurine, Thiamiprine and Thioguanaine; and

Pyrimidine analogs such as Ancitabine, Azacitidine, 6-Azauridine, Carmofur, Cytarabine, Doxifluridine, Enocitabine, Floxuridine Fluroouracil and Tegafur;

Enzymes such as L- Asparaginase; and others such as Aceglatone, Amsacrine, Bestrabucil, Bisantrene, Bryostatin 1, Carboplatin, Cisplatin, Defofamide, Demecolcine, Diaziquone, Elfornithine, Elliptinium Acetate, Etoglucid, Etoposide,

Gallium Nitrate, Hydroxyurea, Interferon-α, Interferon-β, Interferon-γ, Interleukine-2, Lentinan, Letrozole, Lonidamine, Mitoguazone, Mitoxantrone, Mopidamol, Nitracrine, Pentostatin, Phenamet, Pirarubicin, Podophyllinicc Acid, 2- Ethythydrazide, Polynitrocubanes, Procarbazine, PSK7, Razoxane, Sizofiran, Spirogermanium, Taxol, Teniposide, Tenuazonic Acid, Triaziquone, 2.2'.2"-

Trichlorotriethylamine, Urethan, Vinblastine, Vincristine, Vindesine and Vinorelbine;

Antineoplastic (hormonal) drugs, including: Androgens such as Calusterone, Dromostanolone Propionate, Epitiostanol, Mepitiostane and Testolactone;

Antiadrenals such as Aminoglutethimide, Mitotane and Trilostane; Antiandrogens such as Flutamide and Nilutamide; and

Antiestrogens such as Tamoxifen and Toremifene; and

Antineoplastic adjuncts including folic acid replenishers such as Frolinic Acid. Patients having any of a variety of cancers can be treated in this manner for any associated genetic skin disease. Such cancers include those of epithelial origin and others including, but not limited to, squamous cell carcinoma, colorectal cancer, lung cancer, esophageal cancer, breast cancer, laryngeal cancer, hypopharyngeal cancer, bladder cancer, pancreatic cancer, ovarian cancer, gastric cancer and prostate cancer.

4. Identifying compounds having EGFR inhibitory activity. The methods provided herein can employ known EGFR inhibitors as described or incorporated by reference herein, or they can employ agents identified as possessing EGFR inhibitory activity, through screening assays. The biological activity of EGFR, and its reduction in the presence of a putative inhibitor, can be assessed by the exemplary assays provided below and by standard assays known in the art, including but not limited to, in vitro assays, cell-based assays, in vivo assays, animal models and other known biological models. EGFR inhibitors that can be used in the methods and compositions provided herein can be any agents that are known or are identified as inhibiting any step of the signal transduction pathway triggered by EGFR. a. Kinase assays

Kinase activity of the EGFR in the presence or absence of the putative inhibitor can be detected and/or measured directly and indirectly. For example, antibodies against phosphotyrosine can be used to detect phosphorylation of the EGFR or of other proteins and signaling molecules in the signal transduction pathway.

Activation of tyrosine kinase activity of EGFR can be measured in the presence of a ligand for EGFR. The autophosphorylation, detected for example by anti-phosphotyrosine antibodies, can be measured and/or detected in the presence and absence of a putative EGFR inhibitor, thus measuring the ability of the putative inhibitor to effectively reduce EGFR activity. Briefly, cells expressing EGFR are treated with the putative inhibitor. Cells are lysed and protein extracts (whole cell extracts or fractionated extracts) are loaded onto a polyacrylamide gel, separated by electrophoresis and transferred to membrane, such as used for Western blotting. Immunoprecipitation with anti-EGFR antibodies also can be used to fractionate and isolate EGFr before performing gel electrophoresis and western blotting. The membranes can be probed with anti-phosphotyrosine antibodies to detect phosphorylation. Control cells not treated with the putative inhibitor can be subjected to the same procedures for comparison. Tyrosine phosphorylation also can be measured directly, such as by mass spectroscopy. Following treatment of cells expressing EGFR with a putative EGFR inhibitor, the EGFR can be isolated from the cells by immunoprecipitation and trypsinized to produce peptide fragments for analysis by mass spectroscopy. Peptide mass spectroscopy is a well-established method for quantitatively determining the extent of tyrosine phosphorylation for proteins; phosphorylation of tyrosine increases the mass of the peptide ion containing the phosphotyrosine, and this peptide is readily separated from the non-phosphorylated peptide by mass spectroscopy. For example, tyrosine-1139 and tyrosine-1248 are known to be autophosphorylated in ErbB-2. Trypsinized peptides can be empirically determined or predicted based on polypeptide sequence, for example by using ExPASy-

PeptideMass program. The extent of phosphorylation of tyrosine-1139 and tyrosine- 1248 can be determined from the mass spectroscopy data of peptides containing these tyrosines. Such assays can be used to assess the extent of autophosphorylation of EGFR in the presence or absence of a putative EGFR inhibitor. b. Complexation

Complexation, such as dimerization of EGFR, can be detected and/or measured in the presence or absence of a putative EGFR inhibitor. Antibodies recognizing EGFR polypeptides can be used to detect the presence of monomers, dimers and other complexed forms. Alternatively, labeled EGFR can be detected in assays that can assess homodimerization or heterodimerization of EGFR in the presence and absence of a putative inhibitor. c. Ligand binding

Ligand binding (e.g., EGF, TGF-α) modulates the activity of EGFR and thus modulates signaling within the signal transduction pathway. Ligand binding to EGFR can be measured in the presence and absence of a putative inhibitor. For example, radiolabeled ligand such as radiolabeled ligand can be added to purified or partially purified EGFR in the presence and absence of the putative inhibitor. Immunoprecipitation and measurement of radioactivity can be used to quantify the amount of ligand bound to EGFR in the presence and absence of the putative inhibitor. d. Cell Proliferation assays EGFR is known to play a role in cell proliferation. Therefore, the effects of a putative EGFR inhibitor on cell proliferation can be measured. For example, ligand (EGF, TGF-α) can be added to cells expressing EGFR. A putative EGFR inhibitor can be added to such cells before, concurrently or after ligand addition and effects on cell proliferation measured. The cells are incubated at standard growth temperature (e.g. 37⁰C) for several days. Cells are trypsinized, stained with trypan blue and viable cells are counted. Cells not exposed to the putative inhibitor are used as controls for comparison. e. Cell disease model assays

Cells from a disease or condition or which can be modulated to mimic a disease or condition, such as a variety of cancers that over-express EGFR, can be used to measure and/or detect the effect of a putative inhibitor on EGFR. A putative EGFR inhibitor is added to such cells and a phenotype is measured or detected in comparison to cells not exposed to the putative inhibitor. Such assays can be used to measure effects including effects on cell proliferation, metastasis, inflammation, angiogenesis, pathogen infection and bone resorption. f. Animal models

Animal models can be used to assess the effect of a putative inhibitor on EGFR. In an exemplary assay, cancer cells such as ovarian cancer cells are exposed to a putative EGFR inhibitor. After a culturing period in vitro, cells are trypsinized, suspended in a suitable buffer and injected into mice (e.g., into flanks and shoulders of model mice such as Balb/c nude mice). Tumor growth is monitored over time. Control cells, not exposed to a putative EGFR inhibitor, can be injected into mice for comparison. Similar assays can be performed with other cell types and animal models, for example, murine lung carcinoma (LLC) cells and C57BL/6 mice and SCID mice. 5. Assessing the efficacy of EGFR inhibitors in treating genetic skin disorders

Efficacy of the EGFR inhibitors in ameliorating the symptoms/manifestations of a genetic skin disorder can be assessed by measuring in subjects, before and after treatment, a number of parameters including, but not limited to, the extent of lesions, lesion thickness, mean rating of severity, and global examination by a physician. This is exemplified in Examples 1 and 2.

Animal models are available for studying a number of genetic skin disorders including disorders characterized by skin blistering, such as epidermolysis bullosa

(Arm, MJ. and Roop, D.R, Trends MoI. Med. 7:422-424 (2001)), hyperkeratosis disorders characterized by crusty lesions, including Darier's disease (Byrne C.R., J. Invest. Dermatol. 126(4):702-703 (2006); Zhao, X.S. et al, EMBO J. 20(l l}:2680- 2689 (2001); Arin, M.J. and Roop, D.R., Cells Tissues Organs 177(3^:160-168 (2004)), and ichthyosis disorders characterized by scaly skin, such as Netherton syndrome (Hewett, D.R. et al, Hum. MoI. Genet. 14(2):335-346 (2005)). The animal models described in these publications, the contents of each of which are incorporated by reference herein, can be used to test the efficacy of EGFR inhibitors for the prevention and/or treatment of genetic skin disorders. For example, a canine genetic model of Darier's disease exhibits a phenotype similar to Darier's disease, including skin lesions histologically similar to Darier's disease and depleted sarcoplasmic/endoplasmic reticulum-gated calcium stores in keratinocytes. Such a model could be used to test the efficacy of EGFR inhibitors in reducing the severity of the lesions and/or replenishing the keratinocyte calcium stores (Byrne C.R., J. Invest. Dermatol. 126(4):702-703 (2006)). Similarly, a mouse model of Darier's disease, characterized by mutations in the ATP2A2 gene, exhibits perturbations in Ca²⁺ homeostatis and a high incidence of squamous cell carcinomas and papillomas in keratinized epithelial cells, the same cell type affected in human Darier disease (Liu et al, J. Biol. Chem., 276(29):26737-26740 (2001)). The efficacy of EGFR inhibitors can be tested by observing whether treatment with EGFR inhibitors affords a reduction in symptoms associated with the phenotype. B. Methods and Compositions

Provided herein are methods of treating monogenic inherited keratinization disorders by administering to a subject identified as having the disorder a therapeutically effective amount of an EGFR inhibitor. The disorders can be autosomal dominant or autosomal recessive and may further be characterized by hyperkeratosis or ichthyosis. The keratinization disorders can be selected from among over 300 genetic skin disorders as provided or incorporated by reference herein. The keratinization disorder can be selected from among Darier's disease, Hailey-Hailey disease, erythrodermic autosomal recessive lamellar ichthyosis, nonerythrodermic autosomal recessive lamellar ichthyosis, autosomal dominant lamellar ichthyosis, bullous congenital ichthyosiform erythroderma, palmoplantar keratoderma, erythrokeratodermia variabilis, verrucous epidermal nevi, pityriasis rubra pilaris, Netherton syndrome, idiopathic vulgaris, ichthyosis vulgaris, monilethrix, keratosis piliaris, bullous ichthyosiform erythroderma, nonbullous congenital ichthyosis, Sjogren-Larsson syndrome, erythrokeratodermica variabilis, hyperkeratosis lenticularis perstans, eythrokeratodermia fϊgurate variabilis, mutilating keratoderma of Vohwinkel, Harlequin ichthyosis and Tay's syndrome.

The EGFR inhibitors used in the methods provided herein can belong to any one of a number of different types of compounds that inhibit the signal transduction pathway triggered by EGFR. The inhibition can occur at any step of the signal transduction pathway. For example, the EGFR inhibitor can be a monoclonal antibody that inhibits EGFR activity by binding to EGFR in a manner that prevents binding of a ligand, such as epidermal growth factor (EGF), which ordinarily would trigger the EGFR-mediated signal transduction pathway. As another example, the EGFR inhibitor can be a quinazolone compound that inhibits EGFR-mediated signalling by binding to adenosine triphosphate (ATP) and preventing autophosphorylation of EGFR. The EGFR inhibitor can be a known agent as provided herein. Alternately, the EGFR inhibitor can be one that is identified as having EGFR inhibitory activity by conducting assays, as provided herein and as known to those of skill in the art, on a test agent heretofore unidentified as being an

EGFR inhibitor. The EGFR inhibitor can be selected from among quinazolone compounds. A quinazolone compound used as an EGFR inhibitor can be selected from among those provided herein, or a heretofore unknown quinazolone EGFR inhibitor can be identified as having EGFR inhibitory activity by performing assays as provided herein and as known to those of skill in the art. For example, the quinazoline compound is selected from among erlotinib, gefitinib and lapatinib. In one example, the quinazoline compound is erlotinib.

The subject, in addition to having a genetic skin disorder, can further be identified as having cancer. The cancer can be one of many that are known to those of skill in the art, including epithelial cancers. Exemplary cancers include, but are not limited to, squamous cell carcinoma, colorectal cancer, lung cancer, esophageal cancer, breast cancer, laryngeal cancer, hypopharyngeal cancer, bladder cancer, pancreatic cancer, ovarian cancer, gastric cancer and prostate cancer. A subject having a genetic skin disorder and cancer can be administered one or more EGFR inhibitor(s) for treatment of the skin disorder, or they can be administered one or more

EGFR inhibitor(s) for treatment of the skin disorder in combination with a therapeutically effective amount of one or more anticancer agents.

The anticancer agent can be an EGFR inhibitor that is different from the one used to treat the genetic skin disorder, or it can be selected from among other anticancer agents as provided and incorporated by reference herein. Exemplary anticancer agents include irinotecan, cisplatin, carboplatin, oxaliplatin, 5-fluorouracil, leucovorin and radiation treatment. As one example, the anticancer agent is radiation treatment. As another example, the anticancer agent is irinotecan. In yet other examples, the cancer is squamous cell carcinoma and the anticancer agent is radiation treatment, or the cancer is colorectal cancer and the anticancer agent is irinotecan.

The monogenic inherited keratinization disorder treated using an EGFR inhibitor can be Darier's disease. The EGFR inhibitor used to treat Darier's disease can be selected from among the various classes of EGFR inhibitors as provided herein, or an agent that is identified as an EGFR inhibitor by one or more of the assays as provided herein and as known to those of skill in the art. For example, the

EGFR inhibitor is an antibody that binds to EGFR. Exemplary antibodies include, but are not limited to, cetuximab, panitumumab, zalutumumab, nimotuzumab, matuzumab, trastuzumab, ABX-EGF and Mab ICR-62. As one example, the monoclonal antibody is cetuximab. The EGFR inhibitor used to treat Darier's disease can also a quinazoline compound such as, for example, erlotinib.

In the methods as applied to the treatment of Darier's disease, the subject identified as having Darier's disease can further be identified as having cancer. The cancer can be selected from among squamous cell carcinoma, colorectal cancer, lung cancer, esophageal cancer, breast cancer, laryngeal cancer, hypopharyngeal cancer, bladder cancer, pancreatic cancer, ovarian cancer, gastric cancer and prostate cancer. In some examples, the cancer is squamous cell carcinoma. The methods can further include the administration of a therapeutically effective amount of one or more anticancer agent(s). The anticancer agents that is/are administered to the patient identified as having Darier's disease and cancer, may be EGFR inhibitor(s), or they may not be EGFR inhibitors. The anticancer agent can be selected from among those that are provided herein and known to those of skill in the art. Exemplary anticancer agents include, but are not limited to, irinotecan, cisplatin, carboplatin, oxaliplatin, 5- fluorouracil, leucovorin and radiation treatment.

By way of example, the patient identified as having Darier's disease is further identified as having squamous cell carcinoma. In patients having Darier's disease and squamous cell carcinoma, an exemplary treatment can include treating the Darier's disease with an EGFR inhibitor and the squamous cell carcinoma with radiation as the anticancer agent. As another example, the patient identified as having Darier's disease is further identified as having colorectal cancer. In patients having Darier's disease and colorectal cancer, the Darier's disease can be treated with an EGFR inhibitor and the colorectal cancer can be treated using irinotecan as the anticancer agent.

Also provided herein is a method of treating a keratinization disorder by administering to a subject identified as having the keratinization disorder a therapeutically effective amount of an EGFR inhibitor, wherein the EGFR inhibitor is selected from among an antibody that binds to EGFR, an antisense nucleic acid, a quinoxaline, a phenolic stibenoid, a tyrosine metabolite, a flavonoid, an isoflavonoid and methyl-2,5-dihydroxycinnamate. The keratinization disorder can be monogenic or polygenic. The keratinization disorder may be a complex disorder. According to the methods provided herein, any genetic skin disorder, including keratinization disorders, may be treated by administration of an EGFR inhibitor that is an antibody that binds to EGFR. The antibody can be a polyclonal antibody, or it can be a monoclonal antibody. The monoclonal antibody can be selected from among a variety of antibodies as provided herein and as known to those of skill in the art. Exemplary monoclonal antibodies include, but are not limited to, cetuximab, panitumumab, zalutumumab, nimotuzumab, matuzumab, trastuzumab, ABX-EGF and Mab ICR-62. In one example, the monoclonal antibody is cetuximab. The methods provided herein can further include a step of administering one or more additional agents for treating keratinization disorders. The additional agent(s) can be selected from among a number of agents, exemplary of which are an EGFR inhibitor that is different from the EGFR inhibitor administered as the first agent for treatment of the keratinization disorder, a retinoid, a corticosteroid, cyclosporin, an alpha-hydroxy acid, a beta-hydroxy acid, benzoyl peroxide, tazarotene, bexarotene, adapalene and a laser treatment.

Also provided herein are compositions, combinations, kits and articles of manufacture that include an EGFR inhibitor, or an EGFR inhibitor and an anticancer agent, for treating a genetic skin disorder. The compositions, combinations and articles of manufacture can be administered using a variety of routes such as intravenous or other systemic route, topical application, subcutaneous or transdermal application. As one example, provided herein is an article of manufacture that includes an EGFR inhibitor, an anticancer compound and a carrier for topical administration, for treating a genetic skin disorder.

Also provided herein is an article of manufacture that includes an EGFR inhibitor adjusted to a dosage suitable for the treatment of a monogenic keratinization disorder, and a carrier for topical administration. The article of manufacture can, by way of example, contain exclusively an EGFR inhibitor adjusted to a dosage suitable for the treatment of a monogenic keratinization disorder, and a carrier for topical administration. The monogenic keratinization disorder may, for example, be Darier's disease. The articles of manufacture provided herein can further contain a label indicating that the composition is for treating Darier's disease or other skin disorder as provided herein. The EGFR inhibitor contained in the articles of manufacture may be an antibody that binds to EGFR. The antibody can be a polyclonal antibody, or a monoclonal antibody. For example, the antibody can be a monoclonal antibody selected from among cetuximab, panitumumab, zalutumumab, nimotuzumab, matuzumab, trastuzumab, ABX-EGF and Mab ICR-62. In one example, the monoclonal antibody is cetuximab.

The EGFR inhibitor contained in the articles of manufacture can, in some examples, be a quinazolone compound. The quinazoline compound can be selected from among those provided and incorporated by reference herein. By way of examples, the quinazolone compound is selected from among erlotinib, gefϊtinib and lapatinib. In one example, the quinazolone compound is erlotinib.

The articles of manufacture provided herein can further include a delivery system for the EGFR inhibitor. The delivery system can be selected from among a variety of vehicles for administering therapeutic agents, as known to those of skill in the art. For example, the delivery system can be selected from among a transdermal patch, a lotion, a cream, a syringe, an intravenous drip, an intravenous tube, a tablet or a feeding tube.

Also provided herein are compositions containing an EGFR inhibitor, an anticancer agent and a carrier selected for topical administration. The EGFR inhibitor and the anticancer agent can be selected from among any of those provided herein, incorporated by reference herein, identified by assays as provided herein, or known to those of skill in the art.

Therapeutically effective concentrations (for amelioration of the symptoms manifested by the genetic skin disorder) of one or more EGFR inhibitors or pharmaceutically acceptable derivatives thereof are mixed with a suitable pharmaceutical carrier or vehicle for oral, subcutaneous, transdermal, intravenous, intramuscular, ophthalmic or other routes. The EGFR inhibitors are included in an amount effective for reducing the genetic skin disorder for which treatment is contemplated. The concentration of active compound (EGFR inhibitor) in the composition will depend on absorption, inactivation, excretion rates of the active compound, the dosage schedule, and amount administered as well as other factors known to those of skill in the art. Generally, the dosages will be lower, typically at least about or at 5 to 10 fold lower but up to about or at 15, 20, 25, 30, 35, 40, 50, 100, 200 or 500-fold lower, than the amount of EGFR inhibitor administered for the treatment of cancer. The period of administration of the EGFR inhibitor for the treatment of the skin disorder will generally be longer than when administered for the treatment of cancer, because the symptoms of genetic skin disorders generally recur in the absence of treatment. The dosages and period of administration may be empirically determined. Exemplary dosages of an EGFR inhibitor that is an antibody administered as an intravenous infusion can be in the range of from about or at 20 mg/m² to about or at 500 mg/m²; about or at 40 mg/m² to about or at 500 mg/m²; about or at 50 mg/m² to about or at 400 mg/m²; about or at 100 mg/m² to about or at

400 mg/m²; about or at 200 mg/m² to about or at 300 mg/m²; about or at 200 mg/m² to about or at 250 mg/m².

Exemplary dosages of an EGFR inhibitor administered orally, such as a quinazolone compound, can be in the range of from about or at 0.1, 0.2, 0.5, 1, 2, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 115, 125,

150, 200 or 250 mg. The frequency of dosage can be determined empirically; exemplary frequencies are twice daily, daily, weekly, bi-weekly or monthly. Dosage frequencies can be gradually attenuated over time and maintained at a steady dose suitable for long-term - six months, 1 year, 5 years, 10 years or more, up to lifelong administration to control the symtoms of the skin disorder. For example, dosage administration can begin at from three or more times a day, to two times a day, to once a day, to two times a week, to once a week, to once every two weeks or less frequent than once every two weeks.

Pharmaceutical carriers or vehicles suitable for administration of the compounds and for the methods provided herein include any such carriers known to those skilled in the art to be suitable for the particular mode of administration. In addition, the compounds may be formulated as the sole pharmaceutically active ingredient in the composition or may be combined with other active ingredients, such as anticancer agents as provided herein. Typically, a therapeutically effective dosage is formulated to contain a concentration (by weight) of at least about 0.1% up to about 50% or more, and all combinations and subcombinations of ranges therein. The compositions can be formulated to contain the EGFR inhibitor or inhibitor(s) in a concentration of from about 0.1 to less than about 50%, for example, about 49, 48, 47, 46, 45, 44, 43, 42, 41 or 40%, with concentrations of from greater than about 0.1%, for example, about 0.2, 0.3, 0.4 or 0.5%, to less than about 40%, for example, about 39, 38, 37, 36, 35, 34, 33, 32, 31 or 30%. Exemplary compositions may contain from about 0.5% to less than about 30%, for example, about 29, 28, 27, 26, 25, 25, 24, 23, 22, 21 or 20%, with concentrations of from greater than about 0.5%, for example, about 0.6, 0.7, 0.8, 0.9 or 1%, to less than about 20%, for example, about 19, 18, 17, 1 6, 1 5, 14, 13, 12, 11 or 10%. The compositions can contain from greater than about 1% for example, about 2%, to less than about 10%, for example about 9 or 8%, including concentrations of greater than about 2%, for example, about 3 or 4%, to less than about 8%, for example, about 7 or 6%. The active agent can, for example, be present in a concentration of about 5%. In all cases, amounts may be adjusted to compensenate for differences in amounts of active ingredients actually delivered to the treated tissue.

The active ingredient such as the EGFR inhibitor or the EGFR inhibitor combined with an anticancer agent may be administered at once, or may be divided into a number of smaller doses to be administered at intervals of time. It is understood that the precise dosage and duration of treatment is a function of the tissue being treated and may be determined empirically using known testing protocols or by extrapolation from in vivo or in vitro test data. It is to be noted that concentrations and dosage values may also vary with the age of the individual treated. It is to be further understood that, for any particular subject, specific dosage regimens should be adjusted over time according to the individual need and the professional judgment of the person administering or supervising the administration of the compositions, and that the concentration ranges set forth herein are exemplary only. The form and mode of administration of the resulting composition depends upon a number of factors, including the intended application, the subject (whether afflicted with only a genetic skin disorder or a genetic skin disorder and cancer), and the solubility of the active agent(s) in the selected carrier or vehicle. The effective concentration is sufficient for ameliorating the manifestations of the genetic skin disorder, and may be empirically determined. The resulting compositions may be a solution, suspension, emulsion or the like and are formulated as creams, gels, ointments, emulsions, solutions, elixirs, lotions, suspensions, tinctures, pastes, foams, aerosols, irrigations, sprays, suppositories, bandages, injectable solutions, or any other formulation suitable for topical or intravenous or other systemic administration.

Pharmaceutical carriers or vehicles suitable for administration of the compounds provided herein include any such carriers known to those skilled in the art to be suitable for the particular mode of administration. In addition, the compounds may be formulated as the sole pharmaceutically active ingredient in the composition or may be combined with other active ingredients, such as anticancer agents. The active compound(s) is included in the carrier in an amount sufficient to exert a therapeutically useful effect [i.e., amelioration of the symptoms of the genetic skin disorder, or both the skin disorder and cancer, in the case of cancer patients], with minimal or no toxicity or other side effects. For topical administration, the compounds may be formulated in compositions in the form of gels, creams, lotions, solids, solutions or suspensions, or aerosols. Generally, emollient or lubricating vehicles that help hydrate the skin are more preferred than volatile vehicles, such as ethanol, that dry the skin. Examples of suitable bases or vehicles for preparing compositions for use with human skin are petrolatum, petrolatum plus volatile silicones, lanolin, cold cream and hydrophilic ointment.

Suitable pharmaceutically and dermatologically acceptable vehicles for topical application include those suited for use include lotions, creams, solutions, gels, tapes and the like. Generally, the vehicle is either organic in nature or an aqueous emulsion and capable of having the selected compound or compounds, which may be micronized, dispersed, suspended or dissolved therein. The vehicle may include pharmaceutically-acceptable emollients, moisterizers, including lactic acid, ammonium lactate and urea, skin penetration enhancers, coloring agents, fragrances, emulsifiers, thickening agents, and solvents. Depending on the application, the compounds can be formulated and used as tablets, capsules or elixirs for oral administration; salves or ointments for topical application; suppositories for rectal administration; sterile solutions, suspensions, and the like for injection. Injectables can also be prepared in conventional forms either as liquid solutions or suspensions, solid forms suitable for solution or suspension in liquid prior to injection, or as emulsions. Suitable excipients are, for example, water, saline, dextrose, mannitol, lactose, lecithin, albumin, sodium glutamate, cysteine hydrochloride and the like. In addition, if desired, the injectable pharmaceutical compositions can contain minor amounts of nontoxic auxiliary substances, such as wetting agents, pH buffering agents and the like. C. Combinations, Kits, Articles of manufacture

Combinations and kits containing the combinations optionally including instructions for administration are provided. The combinations include, for example, the compositions as provided herein containing one or more EGFR inhibitors, optionally one or more anticancer agents, and reagents or solutions for diluting the compositions to a desired concentration for administration to a host subject, including human beings. Additionally provided herein are kits containing the above-described combinations and optionally instructions for administration by oral, topical, subcutaneous, transdermal, intravenous, intramuscular, ophthalmic or other routes, depending on the agent(s) to be delivered.

The compositions provided herein can be packaged as articles of manufacture containing packaging material, a composition provided herein, and a label that indicates that the composition is for treating a genetic skin disorder, such as Darier's disease, and is formulated for oral delivery, intravenous delivery, or other form of delivery as described herein.

The articles of manufacture provided herein contain packaging materials. Packaging materials for use in packaging pharmaceutical products are well known to those of skill in the art. See, e.g., U.S. Patent Nos. 5,323,907, 5,052,558 and 5,033,252. Examples of pharmaceutical packaging materials include, but are not limited to, blister packs, bottles, tubes, inhalers, pumps, bags, vials, containers, bottles, and any packaging material suitable for a selected formulation and intended mode of administration and treatment. D. Definitions

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of skill in the art. All patents, patent applications, published applications and publications and other published materials referred to throughout the entire disclosure herein, unless noted otherwise, are incorporated by reference in their entirety.

As used herein, a "genetic skin disorder" is any skin disease whose occurrence can be attributed to a defective or abnormal gene or genes. By "defective" or "abnormal," used interchangeably herein, is meant gene(s) that is/are mutated, i.e., point mutations, insertions, deletions, or whose expression is de-regulated, i.e., down- regulated or up-regulated relative to normal expression levels. Exemplary genetic skin disorders include, but are not limited to, Darier's disease, Hailey-Hailey disease, erythrodermic autosomal recessive lamellar ichthyosis, nonerythrodermic autosomal recessive lamellar ichthyosis, autosomal dominant lamellar ichthyosis, bullous congenital ichthyosiform erythroderma, palmoplantar keratoderma, erythrokeratodermia variabilis, verrucous epidermal nevi, pityriasis rubra pilaris, Netherton syndrome, idiopathic vulgaris, ichthyosis vulgaris, monilethrix, keratosis piliaris, bullous ichthyosiform erythroderma, nonbullous congenital ichthyosis, Sjogren-Larsson syndrome, erythrokeratodermica variabilis, hyperkeratosis lenticularis perstans, eythrokeratodermia figurate variabilis, mutilating keratoderma of

Vohwinkel, Harlequin ichthyosis, psoriasis and Tay's syndrome. An extensive list of genetic skin disorders is set forth in Leech et al, Br. J. Dermatol, 156:1115-1148 (2007), the contents of which are incorporated by reference herein.

As used herein, an "inherited skin disorder" is one that is caused by a defective gene or genes that are transmitted from generation to generation in an autosomal dominant, autosomal recessive, or partially or completely co-dominant fashion. An "autosomal dominant" disease is one where the phenotype of the disease can be manifested when one defective allele is present. An "autosomal recessive" disease is one where both alleles must be defective for the disease phenotype to become manifest. A "co-dominant" disease is one where a defective allele and a normal (wild-type) allele combine to produce a phenotype that is intermediate between the normal gene phenotype and the defective gene phenotype. It is understood by those of skill in the art that a person carrying a genotype for a disease (e.g. , present on a single allele for an autosomal dominant disorder, or on both alleles for an autosomal recessive disorder), may nonetheless fail to exhibit the disease gene phenotype, depending on the penetrance of the disease gene. As used herein, "penetrance" is a measure of the likelihood that a person carrying a disease gene will manifest symptoms of the disease. For example, the penetrance of Darier's disease is 100% or complete, which means that every person carrying the mutant allele will exhibit symptoms of the disease, although the degree of severity will vary. As another example, a penetrance of 30% means that only 30% of the subjects carrying the mutant allele in an autosomal dominant disorder, or 30% of subjects carrying both defective alleles in an autosomal recessive disorder, will exhibit symptoms of the disorder.

A "monogenic" skin disorder is one whose cause is attributable to a single gene. An example of a monogenic skin disorder is Darier's disease, an autosomal dominant skin disorder caused by a mutation in the ATP2A2 (an ATPase) gene.

Family members with confirmed identical ATP2A2 mutations can exhibit differences in the clinical severity of disease, suggesting that other genes or environmental factors can affect the expression of Darier's disease. However, a monogenic skin disorder is characterized by the feature of being able to confirm the diagnosis of the disorder (manifested or as a carrier), based on mutations in a single gene. A monogenic skin disorder as used herein can be caused by mutations in more than one alternate gene. For example, the skin disorder epidermolytic hyperkeratosis is caused by mutations in the keratin 1 gene or the keratin 10 gene.

As used herein, a "polygenic" skin disorder is one whose manifestation is attributable to more than one gene. Manifestation of the disease involves the interplay of more than one gene, each of which predisposes the person to the disorder. Examples of polygenic diseases are psoriasis and psoriatic arthritis. Polygenic diseases such as a spectrum of psoriasis disorders often are characterized as "complex" diseases which, as used herein, means that the defective genes are involved in a complex interplay with one or more other factors including other genes, lifestyle, environmental factors and immune responses. As used herein, the term "keratinization disorder" refers to a defect in keratin metabolism. Some keratinization disorders are caused by mutations in keratin genes. In the context of skin diseases, a keratinization disorder usually results in the appearance of scaly and/or thickened skin. Skin keratinization disorders generally are characterized by "hyperkeratosis," which as used herein means the over-production of keratin, and/or "keratinocyte hyperplasia," which as used herein means the generation of a larger than normal number of keratinocytes.

As used herein, the term "ichthyosis" disorder refers to a family of genetic dermatological conditions seen in humans and domestic animals. The word comes from the Greek term for "forming fish," as people or animals with ichthyosis have scaly skin which can vaguely resemble the scales of a fish. While ichthyosis acquisita is acquired (as its name indicates), most forms of ichthyosis are considered congenital. These types include Ichthyosis vulgaris, X-linked ichthyosis, Ichthyosis lamellaris, Epidermolytic hyperkeratosis, Harlequin type ichthyosis, Netherton's syndrome and Sjόgren-Larsson syndrome.

As used herein, a "receptor tyrosine kinase (RTK)" refers to a protein, typically a glycoprotein, that is a member of the growth factor receptor family of proteins. Growth factor receptors are typically involved in cellular processes including cell growth, cell division, differentiation, metabolism and cell migration. RTKs also are known to be involved in cell proliferation, differentiation and determination of cell fate as well as tumor growth. RTKs have a conserved domain structure including an extracellular domain, a membrane-spanning (transmembrane) domain and an intracellular tyrosine kinase domain. Typically, the extracellular domain binds a polypeptide growth factor or a cell membrane-associated molecule. In some cases, an RTK does not bind a ligand, and/or is active independently from ligand binding; for example HER2 is active without ligand binding and a ligand binding HER2 has not been identified. Typically, the tyrosine kinase domain is involved in positive and negative regulation of the receptor. In some cases, for example ErbB3, kinase activity is not present in the receptor alone. Receptor tyrosine kinases have been grouped into families based on, for example, structural arrangements of sequence motifs in their extracellular domains. For example, structural motifs such as, immunoglobulin, fibronectin, cadherin, epidermal growth factor and kringle repeats. Classification by structural motifs has identified greater than 16 families of RTKs, each with a conserved tyrosine kinase domain. Examples of RTKs include, but are not limited to, erythropoietin-producing hepatocellular (EPH) receptors, epidermal growth factor (EGF) receptors, fibroblast growth factor (FGF) receptors, platelet-derived growth factor (PDGF) receptors, vascular endothelial growth factor (VEGF) receptor, cell adhesion RTKs (CAKs), Tie/Tek receptors, insulin-like growth factor (IGF) receptors, and insulin receptor related (IRR) receptors. Exemplary genes encoding RTKs include, but are not limited to, ERBB2, ERBB3, DDRl, DDR2, TKT, EGFR, EPHAl, EPHA8, FGFR2, FGFR4, FLTl (also known as VEGFR-I), FLKl (also known as VEGFR-2) MET, PDGFRA,

PDGFRB, and TEK (also known as TIE-2).

As used herein, "modulate" and "modulation" refer to a change of an activity of a molecule, such as a protein. Activities include, but are not limited to biological activities, such as signal transduction. Modulation can include an increase in the activity (i.e., up-regulation of agonist activity), a decrease in activity (i.e., down- regulation or inhibition) or any other alteration in an activity (such as periodicity, frequency, duration, kinetics). Modulation can be context-dependent and typically modulation is compared to a designated state, for example, the wildtype protein, the protein in a constitutive state, or the protein as expressed in a designated cell type or condition.

As used herein, "inhibit" and "inhibition" refer to a reduction in a biological activity, and "inhibitor" refers to a molecule that effects the reduction in biological activity. The reduction in activity generally contemplated herein is anywhere from about or at 10% reduction of the normal biological activity to about or at 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%,

95%, 96%, 97%, 98%, 99% or 100% reduction of the normal biological activity.

In the context of receptor tyrosine kinases, such as EGFR, "inhibitors" refer to any of a large class of compounds capable of modulating tyrosine kinase signal transduction. Thus, the inhibitors can include molecules such as antibodies that compete for binding of the ligand (EGF, TGF-α) to EGFR, or they can include molecules such as quinazolones that bind to ATP and inhibit autophosphorylation of EGFR, or they can include any inhibitor that blocks the signal transduction pathway mediated by the interaction of EGF with EGFR. Examples of tyrosine kinase inhibitors and molecules capable of modulating tyrosine kinase signal transduction include, but are not limited to, 4-aminopyrrolo[2,3-d]pyrimidines (see for example, U.S. Pat. No. 5,639,757), and quinazoline compounds and compositions (e.g., U.S. Pat. No. 5,792,771). A variety of EGFR inhibitors are listed, for example, in U.S.

Patent Nos. 5,914,269; 6,187,585; 6,638,543; 6,004,967; and 7,247,301; and U.S. published Application Nos. US20060263349 Al and US20070282276 Al . The contents of each of the references which are incorporated in their entirety by reference herein. Exemplary of these inhibitors are antibodies that bind to EGFR, antisense nucleic acids, tyrphostins, quinazolone compounds, 2-phenylaminopyrimidines, quinoxalines, phenolic stibenoids, tyrosine metabolites, flavonoids, isoflavonoids and methy 1-2 , 5 -dihy droxy cinnamate .

As used herein, a "composition" refers to any mixture. It can be a solution, a suspension, liquid, powder, a paste, aqueous, non-aqueous or any combination thereof.

As used herein, a "combination" refers to any association between or among two or more items. The combination can be two or more separate items, such as two compositions or two collections, can be a mixture thereof, such as a single mixture of the two or more items, or any variation thereof. As used herein, a "pharmaceutical effect" refers to an effect observed upon administration of an agent intended for treatment of a disease or disorder or for amelioration of the symptoms thereof.

As used herein, "treatment" means any manner in which the symptoms of a condition, disorder or disease or other indication, are ameliorated or otherwise beneficially altered.

As used herein, "therapeutic effect" means an effect resulting from treatment of a subject that alters and typically improves or ameliorates the symptoms of a disease or condition or that cures or prevents a disease or condition. A therapeutically effective amount refers to the amount of a composition, molecule or compound which results in a therapeutic effect following administration to a subject.

As used herein, the term "prevention" means that the statistical likelihood of manifestation of the disease in the presence of the preventative (drug or prophylactic, e.g., an EGFR inhibitor) is less than the statistical likelihood of occurrence of the disease in the absence of the preventative. "Prevention" as used herein can also mean there is a delay in the onset of symptoms of the disease. The reduction in likelihood of occurrence, or the delay in onset of symptoms of the disease, can be anywhere from a factor of about or at 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%,

55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100%.

As used herein, the term "subject" refers to animals, including mammals, such as human beings. As used herein, a patient refers to a human subject.

As used herein, a "biological activity" refers to a function of a polypeptide including but not limited to complexation, dimerization, multimerization, phosphorylation, dephosphorylation, autophosphorylation, ability to form complexes with other molecules, ligand binding, catalytic or enzymatic activity, activation including auto-activation and activation of other polypeptides, inhibition or modulation of another molecule's function, stimulation or inhibition of signal transduction and/or cellular responses such as cell proliferation, migration, differentiation, and growth, degradation, membrane localization, membrane binding, and oncogenesis. A biological activity can be assessed by assays described herein and by standard assays known in the art, including but not limited to, in vitro assays, cell- based assays, in vivo assays, animal models and other known biological models. In general, the terms "activity" or "function" are interchangeable with

"biological activity" and refer to the in vivo activities of a compound, such as a protein, vitamin, mineral or drug, or physiological responses that result upon in vivo administration of a compound, composition or other mixture. Activity, thus, encompasses therapeutic effects and pharmaceutical activity of compounds, compositions and mixtures. Biological activities also can be observed in in vitro systems designed to test or use such activities.

As used herein, a "kit" refers to a combination in which components are packaged optionally with instructions for use and/or reagents and apparatus for use with the combination. As used herein, the term "polypeptide," means at least two amino acids, or amino acid derivatives, including mass modified amino acids and amino acid analogs, that are linked by a peptide bond, which can be a modified peptide bond. The terms "polypeptide," "peptide" and "protein" are used synonymously herein. A polypeptide can be associated with one or more functional activities including, but not limited to, a nutrient to provide amino acid building blocks, an antioxidant, an enzyme, an antibody, a regulator of gene expression, a scaffold, etc. As used herein, therapeutically effective amount refers to an amount of the active agent for a desired therapeutic, prophylactic, or other biological effect or response when a composition is administered to a subject in a single or multiple dosage form. The particular amount of active agent in a dosage will vary widely according to conditions such as the nature of the active agent, the nature of the condition being treated, the age and size of the subject.

As used herein, pharmaceutically acceptable derivatives of a compound, such as an EGFR inhibitor, include salts, esters, enol ethers, enol esters, acids, bases, solvates, hydrates or prodrugs thereof. Such derivatives can be readily prepared by those of skill in this art using known methods for such derivatization. The compounds produced can be administered to animals or humans without substantial toxic effects and either are pharmaceutically active or are prodrugs. Pharmaceutically acceptable salts include, but are not limited to, amine salts, such as but not limited to N₅N'- dibenzylethylenediamine, chloroprocaine, choline, ammonia, diethanolamine and other hydroxyalkylamines, ethylenediamine, N-methylglucamine, procaine, N- benzylphenethylamine, 1 -para-chlorobenzyl-2-pyrrolidin- 1 '-ylmethylbenzimidazole, diethylamine and other alkylamines, piperazine and tris(hydroxymethyl)aminomethane; alkali metal salts, such as but not limited to lithium, potassium and sodium; alkali earth metal salts, such as but not limited to barium, calcium and magnesium; transition metal salts, such as but not limited to zinc; and other metal salts, such as but not limited to sodium hydrogen phosphate and disodium phosphate; and also including, but not limited to, salts of mineral acids, such as but not limited to hydrochlorides and sulfates; and salts of organic acids, such as but not limited to acetates, lactates, malates, tartrates, citrates, ascorbates, succinates, butyrates, valerates and fumarates. Pharmaceutically acceptable esters include, but are not limited to, alkyl, alkenyl, alkynyl, aryl, heteroaryl, aralkyl, heteroaralkyl, cycloalkyl and heterocyclyl esters of acidic groups, including, but not limited to, carboxylic acids, phosphoric acids, phosphinic acids, sulfonic acids, sulfϊnic acids and boronic acids.

The following examples are exemplary only and are not intended to limit the scope of the subject matter claimed herein.

EXAMPLE 1

Treatment of Darier's disease using the EGFR inhibitor antibody ERBITUX® (Cetuximab) :

A patient with stage IV squamous cell carcinoma, originally diagnosed in September, 2006, and a long-standing history of Darier's disease, was examined for possible therapeutic options to treat the malignancy. The patient had, in the past, tried ACCUTANE® (Hoffman-La Roche, Nutley, New Jersey) to manage the symptoms of Darier's disease. Shortly prior to the time of examination for treatment of the stage IV squamous cell carcinoma, the patient had been on SORIATANE® (Hoffman-La Roche, Nutley, New Jersey) 25 mg. orally, once a day, for treatment of Darier's disease. The patient had discontinued the SORIATANE® as it produced only a modest reduction in severity of the lesions

Physical examination of the patient revealed the presence of lichenified, indurated popular lesions throughout the entire body, characteristic of Darier's disease. The patient had had a metastatic squamous cell mass in the right groin with a fungating wound, which had been excised. At the examination, it was determined that the patient would need palliative radiation therapy to the right groin, beginning in one week. In addition, the decision was made to administer monoclonal antibody therapy to treat the cancer. The patient was administered the monoclonal antibody ERBITUX® (ImClone, New York, New York; also known as cetuximab) as a 200 mg/m² intravenous (i.v.) infusion on the day of examination. This was followed in one week by the administration of 400 mg/m² i.v. infusion of cetuximab, along with the radiation therapy. Thereafter, weekly i.v. infusions of cetuximab were continued at 250 mg/m², co-administered with radiation therapy, for a total often i.v. infusions. The patient tolerated the infusions well; with the exception of a brief episode of chills during the administration, no other toxicities or other side effects such as fever, chills, chest pain or shortness of breath were reported. Examination of the patient showed a dramatic reduction in the lesions associated with Darier's disease. The skin lesions had almost entirely cleared in the forearm within eleven weeks of treatment with cetuximab, and in the forehead within six weeks of treatment with cetuximab.

EXAMPLE 2

Treatment of Darier's disease using the EGFR inhibitor quinazolone compound TARCEVA® (Erlotinib) :

A patient with stage IV squamous cell carcinoma and a long-standing history of Darier's disease, was examined for a clinical update and possible options for further treatments. The patient had recently completed a treatment often weekly infusions of cetuximab (as described in Example 1), as adjuvant therapy for the metastatic squamous cell carcinoma. The cetuximab had shown dramatic effects in reducing the lesions associated with Darier's disease. The patient had taken ACCUTANE® and SORIATANE® (retinoids) in the past, for treating Darier's disease, and neither of the treatments had shown a good response.

The patient started taking TARCEVA® (erlotinib; OSI Pharmaceuticals, Melville, NY), 150 mg orally per day, as adjuvant therapy for the metastatic squamous cell carcinoma. The patient tolerated treatment with TARCEVA® well, with no side effects or other complications. Treatment led to a significant reduction in severity of the Darier's lesions.

At the time of examination, the patient had been off TARCEVA® for five weeks, and the Darier's lesions had deteriorated at all sites. Treatment with TARCEVA® was resumed on the day of examination as adjuvant therapy for the metastatic squamous cell carcinoma. The treatment for over six months was very well-tolerated by the patient, and resulted in a dramatic reduction of the severity of Darier's lesions. In fact, within six weeks, the lesions associated with the disease had almost cleared, relative to the period when the patient had been off TARCEVA®.

Claims

WHAT IS CLAIMED IS:

1. A method of treating a monogenic inherited keratinization disorder, comprising administering to a subject identified as having the disorder a therapeutically effective amount of an EGFR inhibitor.

2. A method of treating a keratinization disorder, comprising administering to a subject identified as having the keratinization disorder a therapeutically effective amount of an EGFR inhibitor, wherein the EGFR inhibitor is selected from among an antibody that binds to EGFR, an antisense nucleic acid, a quinoxaline, a phenolic stibenoid, a tyrosine metabolite, a flavonoid, an isoflavonoid and methyl-2,5- dihy droxy cinnamate .

3. The method of claim 1, wherein the EGFR inhibitor is selected from among an antibody that binds to EGFR, an antisense nucleic acid, a tyrphostin, a quinazolone compound, a quinazoline compound, a quinazolinamine compound, a 2- phenylaminopyrimidine, a quinoxaline, a phenolic stibenoid, a tyrosine metabolite, a flavonoid, an isoflavonoid and methyl-2,5-dihydroxycinnamate.

4. The method of claim 1 or claim 2, wherein the EGFR inhibitor is an antibody that binds to EGFR.

5. The method of claim 4, wherein the antibody is a monoclonal antibody.

6. The method of claim 5, wherein the monoclonal antibody is selected from among cetuximab, panitumumab, zalutumumab, nimotuzumab, matuzumab, trastuzumab, ABX-EGF and Mab ICR-62.

7. The method of claim 6, wherein the monoclonal antibody is cetuximab.

8. The method of claim 1, wherein the EGFR inhibitor is a quinazoline compound.

9. The method of claim 8, wherein the quinazoline compound is selected from among erlotinib, gefitinib and lapatinib.

10. The method of claim 8, wherein the quinazoline compound is erlotinib.

11. The method of claim 2, wherein the keratinization disorder is monogenic.

12. The method of claim 2, wherein the keratinization disorder is polygenic.

13. The method of claim 2, wherein the keratinization disorder is complex.

14. The method of claim 1, wherein the disorder is autosomal dominant.

15. The method of claim 1, wherein the disorder is autosomal recessive.

16. The method of any of claims 1-15, further comprising the administration of one or more additional agents for treating keratinization disorders.

17. The method of claim 16, wherein the additional agent(s) is/are selected from among an EGFR inhibitor, a retinoid, a corticosteroid, cyclosporin, an alpha- hydroxy acid, a beta-hydroxy acid, benzoyl peroxide, tazarotene, bexarotene, adapalene and a laser treatment.

18. The method of claim 1, wherein the keratinization disorder is a hyperkeratosis disorder or an ichthyosis disorder.

19. The method of claim 18, wherein the keratinization disorder is selected from among Darier's disease, Hailey-Hailey disease, erythrodermic autosomal recessive lamellar ichthyosis, nonerythrodermic autosomal recessive lamellar ichthyosis, autosomal dominant lamellar ichthyosis, bullous congenital ichthyosiform erythroderma, palmoplantar keratoderma, erythrokeratodermia variabilis, verrucous epidermal nevi, pityriasis rubra pilaris, Netherton syndrome, idiopathic vulgaris, ichthyosis vulgaris, monilethrix, keratosis piliaris, bullous ichthyosiform erythroderma, nonbullous congenital ichthyosis, Sjogren-Larsson syndrome, erythrokeratodermica variabilis, hyperkeratosis lenticularis perstans, eythrokeratodermia fϊgurate variabilis, mutilating keratoderma of Vohwinkel, Harlequin ichthyosis and Tay's syndrome.

20. The method of any of claims 1 and 3-7, wherein the subject is further identified as having cancer.

21. The method of claim 20, wherein the cancer is selected from among squamous cell carcinoma, colorectal cancer, lung cancer, esophageal cancer, breast cancer, laryngeal cancer, hypopharyngeal cancer, bladder cancer, pancreatic cancer, ovarian cancer, gastric cancer and prostate cancer.

22. The method of claim 20 or claim 21, further comprising the administration of a therapeutically effective amount of one or more anticancer agent(s), wherein the anticancer agent(s) is/are not an EGFR inhibitor.

23. The method of claim 22, wherein the anticancer agent is selected from among irinotecan, cisplatin, carboplatin, oxaliplatin, 5-fluorouracil, leucovorin and radiation treatment.

24. The method of claim 23, wherein the cancer is squamous cell carcinoma and the anticancer agent is radiation treatment.

25. The method of claim 23, wherein the cancer is colorectal cancer and the anticancer agent is irinotecan.

26. The method of claim 19, wherein the disorder is Darier's disease.

27. The method of claim 26, wherein the EGFR inhibitor is an antibody that binds to EGFR.

28. The method of claim 27, wherein the antibody is cetuximab.

29. The method of claim 26, wherein the EGFR inhibitor is a quinazoline compound.

30. The method of claim 29, wherein the compound is erlotinib.

31. The method of claim 26, wherein the subject is further identified as having cancer.

32. The method of claim 31, wherein the cancer is selected from among squamous cell carcinoma, colorectal cancer, lung cancer, esophageal cancer, breast cancer, laryngeal cancer, hypopharyngeal cancer, bladder cancer, pancreatic cancer, ovarian cancer, gastric cancer and prostate cancer.

33. The method of claim 32, wherein the cancer is squamous cell carcinoma.

34. The method of claim 31 or claim 32, further comprising the administration of a therapeutically effective amount of one or more anticancer agent(s), wherein the anticancer agent(s) is/are not an EGFR inhibitor.

35. The method of claim 34, wherein the anticancer agent is selected from among irinotecan, cisplatin, carboplatin, oxaliplatin, 5-fluorouracil, leucovorin and radiation treatment.

36. The method of claim 35, wherein the cancer is squamous cell carcinoma and the anticancer agent is radiation treatment.

37. The method of claim 35, wherein the cancer is colorectal cancer and the anticancer agent is irinotecan.

38. An article of manufacture, comprising an EGFR inhibitor, an anticancer compound and a carrier for topical administration, for treating a genetic skin disorder.

39. An article of manufacture, comprising an EGFR inhibitor and a carrier for topical administration, wherein the amount of the EGFR inhibitor is adjusted to a dosage suitable for treating a monogenic keratinization disorder.

40. A pharmaceutical composition comprising an EGFR inhibitor, an anticancer agent and a carrier selected for topical administration.

41. The article of claim 39, wherein the article of manufacture further comprises a label indicating that the composition is for treating Darier's disease.

42. The article of claim 38 or claim 39, wherein the EGFR inhibitor is an antibody that binds to EGFR.

43. The article of claim 42, wherein the antibody is a monoclonal antibody.

44. The article of claim 43, wherein the monoclonal antibody is selected from among cetuximab, panitumumab, zalutumumab, nimotuzumab, matuzumab, trastuzumab, ABX-EGF and Mab ICR-62.

45. The article of claim 44, wherein the monoclonal antibody is cetuximab.

46. The article of claim 38 or claim 39, wherein the EGFR inhibitor is a quinazoline compound.

47. The article of claim 46, wherein the quinazoline compound is selected from among erlotinib, gefitinib and lapatinib.

48. The article of claim 47, wherein the quinalozine compound is erlotinib.

49. The article of any of claims 38, 39 and 41-48, further comprising a delivery system for the EGFR inhibitor.

50. The article of claim 49, wherein the delivery system is selected from among a transdermal patch, a lotion, a cream, a syringe, an intravenous drip, an intravenous tube, a tablet or a feeding tube.