(12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT)
`
`(19) World Intellectual Property Organization
`International Bureau
`
`(43) International Publication Date
`17 October 2002 (17.10.2002)
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` (10) International Publication Number
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`WO 02/080932 A1
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`(51) International Patent Classificationlz
`
`A61K 31/65
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`(21) International Application Number:
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`PCT/USO2/10747
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`(22) International Filing Date:
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`5 April 2002 (05.04.2002)
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`(25) Filing Language:
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`(26) Publication Language:
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`English
`
`English
`
`(30) Priority Data:
`60/281,916
`
`5 April 2001 (05.04.2001)
`
`US
`
`(71) Applicant 0’0r all designated States except US): COL-
`LAGENEX PHARMACEUTICALS, INC. [US/US]; 41
`University Drive, Newtown, PA 18940 (US).
`
`(72) Inventor; and
`(75) Inventor/Applicant (for US only): ASHLEY, Robert, A.
`[US/US]; 63 Woodhill Road, Newtown, PA 18940 (US).
`
`(81) Designated States (national): AE, AG, AL, AM, AT, AU,
`AZ, BA, BB, BG, BR, BY, BZ, CA, CH, CN, CO, CR, CU,
`CZ, DE, DK, DM, DZ, EC, EE, ES, FI, GB, GD, GE, GH,
`GM, HR, HU, lD, lL, lN, lS, JP, KE, KG, KP, KR, KZ, LC,
`LK, LR, LS, LT, LU, LV, MA, MD, MG, MK, MN, MW,
`MX, MZ, NO, NZ, OM, PH, PL, PT, RO, RU, SD, SE, SG,
`SI, SK, SL, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ,
`VN, YU, ZA, ZM, ZW.
`
`(84) Designated States (regional): ARIPO patent (GH, GM,
`KE, LS, MW, MZ, SD, SL, SZ, TZ, UG, ZM, ZW),
`Eurasian patent (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM),
`European patent (AT, BE, CH, CY, DE, DK, ES, FI, FR,
`GB, GR, IE, IT, LU, MC, NL, PT, SE, TR), OAPI patent
`(BF, BJ, CF, CG, CI, CM, GA, GN, GQ, GW, ML, MR,
`NE, SN, TD, TG).
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`Published:
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`with international search report
`before the expiration of the time limit for amending the
`claims and to be republished in the event of receipt of
`amendments
`
`(74) Agents: BARON, Ronald, J. et al.; Hoffmann & Baron,
`LLP, 6900 Jericho Turnpike, Syosset, NY 11791 (US).
`
`For two-letter codes and other abbreviations, refer to the ”Guid-
`ance Notes on Codes andAbbreviations " appearing at the begin-
`ning ofeach regular issue ofthe PCT Gazette.
`
`O02/080932A1
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`(54) Title: METHODS OF TREATING ACNE
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`(57) Abstract: A method of treating acne in a human in need thereof comprising adminestering systemically to said human a tetra—
`cycline compound in an amount that is effective to treat acne but has substantially no antibiotic activity, without administering a
`bisphoshonate compound.
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`NIETHODS OF TREATING ACNE
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`CROSS—REFERENCE TO RELATED APPLICATION
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`This application claims the benefit of US. Provisional Application No.
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`60/281,916, filed April 5, 2001, and U.S. Provisional Application No. 60/325,489,
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`filed September 26, 2001, both of which are incorporated herein by reference.
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`BACKGROUND OF THE INVENTION
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`Acne is a common disease characterized by various types of lesions. The
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`areas affected typically are areas of the skin Where sebaceous glands are largest, most
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`numerous, and most active. The lesions associated with acne are usually categorized
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`as either non—inflammatory or inflammatory.
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`Non-inflammatory lesions include comedones. Comedones appear in two
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`forms, open and closed. Comedones are thought to arise from abnormal follicular
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`differentiation. Instead of undergoing shedding and discharge through the follicular
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`orifice, abnormal desquamated cells (keratinocytes) become unusually cohesive,
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`forming a microcomedo or a microscopic hyperkeratotic plug in the follicular canal.
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`The progressive accumulation of these microcomedones lead to visible comedones.
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`In its mildest form, acne is a more or less superficial disorder characterized by
`slight, spotty skin irritations. In such cases, ordinary skin hygiene is typically a
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`satisfactory treatment. In the more inflammatory types of acne, however, pustules;
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`infected cysts; and in extreme cases, canalizing, inflamed and infected sacs appear.
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`Without effective treatment, these lesions may become extensive and leave
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`permanent, disfiguring scars.
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`Microorganisms, especially Propz'onz'bacterium acnes, are strongly implicated
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`in the pathogenesis of acne. The microorganisms are thought to release microbial
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`mediators of inflammation into the dermis or trigger the release of cytokines from
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`ductal keratinocytes.
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`Accordingly, the efficacy of antibiotics in treating acne is thought to be due, in
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`significant part, to the direct inhibitory effect of the antibiotics on the growth and
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`metabolism of these microorganisms. Systemically—administered tetracycline
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`antibiotics, especially minocycline hydrochloride, are particularly effective in treating
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`acne.
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`The tetracyclines are a class of compounds of which tetracycline is the parent
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`compound. Tetracycline has the following general structure:
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`Tetracycline, as well as the 5-hydroxy (oxytetracycline, e.g. Terramycin) and
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`7—_chloro (chlorotetracycline, e.g. Aureomycin) derivatives, exist in nature, and are all
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`well known antibiotics. Semisynthetic derivatives such as 7—
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`dimethylaminotetracycline (minocycline) and 6oz—deoxy—5—hydroxytetracycline
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`(doxycycline) are also known tetracycline antibiotics. Natural tetracyclines may be
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`modified Without losing their antibiotic properties, although certain elements of the
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`structure must be retained to do so.
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`'In addition'to the direct antibiotic activity of tetracyclines, further activities of
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`antibiotic tetracyclines have been investigated for possible therapeutic effects on acne.
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`For example, a study by Elewski et al., J. Amer. Acad. Dermatol. , 82807-812
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`(1983) suggests that acne therapy, consisting of orally—administered tetracycline at a
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`total daily dose of 1000 mg, may have therapeutic anti—inflammatory effects in
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`addition to antibiotic effects. In particular, it was found that the anti—inflammatory
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`effect of tetracycline was, at least in part, due to inhibition of neutrophil chemotaxis
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`induced by bacterial chemotactic factors.
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`A more recent study, performed by Eady et a1., J. Invest. Dermatol, [01:86-91
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`(1993), evaluated the effects of oral minocycline or tetracycline therapy on the
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`cytokine and microflora content of open comedones in acne patients. The total daily
`dose of minocycline administered was 100 mg. The total daily doseiof tetracycline
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`administered was 1000 mg.
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`Eady et al. found that the therapies upregulated the production of bioactive IL-
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`10(—1ike material and immunochemical [L-lB.
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`IL—1 is considered to be a pro—
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`inflamrnatory cytokine.
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`,
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`Accordingly to Eady et a1., no overall decrease in the numbers of
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`propionibacteria/mg of comedonal material was found. It is important to note,
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`however, that the numbers of propionibacteria/mg of comedonal material are not
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`expected to decrease in response to antibiotic therapy. Since the bacteria within
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`comedones are encapsulated by the follicle, they are not susceptible to antibiotic
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`treatment.
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`Another possible activity of tetracyclines in acne therapy was investigated by
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`Bodokh, I., et a1., Acta. Derm. Venerol., 77255—259 (1997). Their study was
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`designed to evaluate the action of minocycline on sebaceous excretion in acne
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`patients. A 100mg daily dose of minocycline was administered. A subclinical
`increase in seborrhoea was reported. The authors propose that minocycline induces
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`an increase in seborrhoea via a reduction in ductal obstruction. The mechanism by
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`Which the ductal obstruction is reduced is proposed to be a reduction in ductal
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`irritation. The authors suggest that the reduction of ductal irritation is due to
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`minocycline’s direct effect on P. acnes, or minocycline’s effect on the lipase
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`produced by P. acnes.
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`Bodokh et al. also found that during treatment no correlation exists between
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`seborrhoea intensity and clinical severity of acne. The authors state that the lack of
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`correlation shows that seborrhoea is pathogenic because it is the “culture medium” of
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`P. acnes. Thus, it can be concluded that the authors consider the antibiotic activity of
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`minocycline to be therapeutically significant with respect to acne.
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`Similarly, in a recent clinical study it was reported that tetracycline in sub-
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`antibiotic doses had no clinical effect 011 acne. (Cunliffe et al., J. Am. Acaa’.
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`Dermatol, 1 6:5 91—9 (1987).) In particular, a 100 mg total daily dose of minocycline
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`and a 1.0g total daily dose of tetracycline Were found to be necessary to successfully
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`treat acne.
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`The antibiotic effects of antibiotics are generally directly proportional to the
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`dose administered of the antibiotics. Accordingly, in moderate to severe (i.e.
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`inflammatory) forms of acne, oral antibiotics are typically administered at high doses.
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`For example, in conventional acne therapy, tetracycline is administered at an initial
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`dose of 500 to 2,000 mg/day, followed by a maintenance dose of 250-500 mg/day.
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`Clearly, the state-of—the-art teaching is that the clinical efficacy of
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`systemically—administered tetracyclines in the treatment of acne is due, at least in
`significant part, to the antibiotic effects of the tetracyclines. In addition to their
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`antibiotic effects, it has been proposed that tetracyclines reduce the number of
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`inflammatory lesions (papules, pustules and nodules) by a variety of non—antibiotic
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`mechanisms. Such mechanisms include interfering with the chemotaxis of
`polymorphonuclear leukocytes (PNlNlinto the inflammatory lesion, inhibition of
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`PMN derived collagenase, and by scavenging reactive oxidative species produced by
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`resident inflammatory cells.
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`There is no disclosure in the prior art of using either a sub-antibiotic dose of
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`an antibiotic tetracycline compound, or of using a non-antibiotic tetracycline
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`compound for the treatment of acne.
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`The-use of tetracycline antibiotics, however, can lead to undesirable side
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`effects. For example, the long term administration of antibiotic tetracyclines can
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`reduce or eliminate healthy microbial flora, such as intestinal flora, and can lead to the
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`production of antibiotic resistant organisms or the overgrth of yeast and fungi.
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`Accordingly, there is a need for an effective treatment of acne which causes
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`fewer undesirable side effects produced by the systemically-administered antibiotics
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`used in conventional acne therapy.
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`SUMTMARY OF INVENTION
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`The present invention provides a method of treating acne in a human in need
`
`thereof. The method comprises administering systemically to the human a
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`tetracycline compound in an amount that is effective to treat acne but has substantially
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`no antibiotic activity (i.e. substantially no antimicrobial activity), Without
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`administering a bisphosphonate compound.
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`Additionally, the present invention provides methods for reducing the number
`of comedones, inhibiting oxidation ofmelanin, and/or inhibiting lipid—associated
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`abnormal follicular differentiation in a human in need thereof. These methods
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`compn'se administering systemically to the human a tetracycline compound in an
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`amount that is effective for its purpose, e.g., to reduce the number ofcomedones, to
`inhibit oxidation ofmelanin, and/or to inhibit lipid-associated abnormal follicular
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`differentiation, but has substantially no antibiotic activity.
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`BRIEF DESCRIPTION OF THE DRAWINGS
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`Figure 1 shows the photoirritancy factor (PIF) for some tetracycline
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`compounds. For structure K, the compounds indicated are as follows:
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`R7
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`311
`3 06
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`hydrogen
`hydrogen
`hydrogen
`
`R8
`
`hydrogen
`hydrogen
`hydrogen
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`R9
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`amino
`palmitamide
`dimethylamino
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`For structures L, M, N or O the compounds indicated are as follovvs:
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`R7
`
`R8
`
`4
`
`R9
`
`801
`802
`804
`805
`
`hydrogen
`hydrogen
`hydrogen
`hydrogen
`
`hydrogen
`hydrogen
`hydrogen
`hydrogen
`
`acetamido
`-
`dimethylaminoacetamido
`nitro
`amino
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`For structure P, R8 is hydrogen and R9 is nitro.
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`DETAILED DESCRIPTION
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`The present invention provides methods oftreating acne. As used herein, the
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`term "acne" is a disorder of the skin characterized by papules, pustules, cysts, nodules,
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`comedones, and other blemishes or skin lesions. These blemishes and lesions are
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`often accompanied by inflammation of the skin glands and pilosebaceous follicles, as
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`well as, microbial, especially bacterial, infection.
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`F‘or'the purposes of‘thi‘s specification, acne includesall known types of acne.
`Some types of acne include, for example, acne Vulgaris, cystic acne, acne atrophica,
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`bromide acne, chlorine acne, acne conglobata, acne cosmetica, acne detergicans,
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`epidemic acne, acne estivalis, acne fulminans, halogen acne, acne indurata, iodide
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`acne, acne keloid, acne mechanica, acne papulosa, pomade acne, premenstral acne,
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`acne pustulosa, acne scorbutica, acne scrofulosorum, acne urticata, acne varioliformis,
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`acne venenata, propionic acne, acne excoriee, gram negative acne, steroid acne,
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`nodulocystic acne and acne rosacea. Acne rosacea is characterized by inflammatory
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`lesions (erythema) and permanent dilation of blood vessels (telangectasia).
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`The present invention is particularly effective in treating comedones, e. g.,
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`reducing the number of comedones. Both open and closed comedones can be treated
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`in accordance with the methods of this invention.
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`The present invention can also be used to treat certain other types of acneiform
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`dermal disorders, e. g. perioral dermatitis, seborrheic dermatitis in the presence of
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`acne, gram negative folliculitis, sebaceous gland dysfunction, hiddradenitis
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`suppurativa, pseudo—folliculitis barbae, or folliculitis.
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`The method comprises the administration of a tetracycline compound to a
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`human in an amount which is effective for its purpose e. g., the treatment of acne,
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`including reducing the number of comedones, but which has substantially no
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`antibiotic activity.
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`The tetracycline compound can be an antibiotic or non—antibiotic compound.
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`The tetracycline compound has the general tetracycline structure indicated above, or a
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`derivative thereof.
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`Some examples of antibiotic (i.e. antimicrobial) tetracycline compounds,
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`include doxycycline, minocy'cline, tetracycline, oxytetracycline, chlortetracycline,
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`demeclocycline, lymecycline and their phannaceutically acceptable salts.
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`Doxycycline is preferably administered as its hyclate salt or as a hydrate, preferably
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`monohydrate.
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`Non-antibiotic tetracycline compounds are structurally related to the antibiotic
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`tetracyclines, but have had their antibiotic activity substantially or completely
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`eliminated by chemical modification. For example, non—antibiotic tetracycline
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`compounds are Capable of achieving antibiotic activity comparable to that of
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`tetracycline or doxycycline at concentrations at least about ten times, preferably at
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`least about twenty five times, greater than that of tetracycline or doxycycline,
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`respectively.
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`Examples of chemically modified non—antibiotic tetracyclines (CMTs) include
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`4—de(dimethylamino)tetracycline (GMT-1), tetracyclinonitrile (GMT—2), 6—demethyl—
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`6-deoxy—4-de(dimethylamino)tetracycline (GMT-3), 7—chloro—4—
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`de(dimethylamino)tetracycline (CMT~4), tetracycline pyrazole (GMT—5), 4—hydroxy-
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`4-de(dimethylamino)tetracycline (GMT-6), 4-de(dimethylamino-12a-
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`deoxytetracycline (GMT—7), 6-deoxy-5oz-hydroxy—4-de(dimethylamino)tetracycline
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`(GMT-8), 4-de(dimethylamino)-l2oz—deoxyanhydrotetracycline (CMT—9), 4-
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`de(dimethylamino)minocycline (GMT—10).
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`Further examples of chemically modified non-antibiotic tetracyclines include
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`Structures C-Z. (See Index of Structures.)
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`Tetracycline derivatives, for purposes of the invention, may be any
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`tetracycline derivative, including those compounds disclosed generically or
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`specifically in co-pending U.S. patent application serial no. 09/573,654 filed on May
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`18, 2000, which are herein incorporated by reference.
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`The minimal amount of the tetracycline compound administered to a human is
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`the lowest amount capable of providing effective treatment of acne. Effective
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`treatment is a reduction or inhibition of the blemishes and lesions associated with
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`acne. The amount of the tetracycline compound is such that it does not significantly
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`prevent the growth of microbes, e.g. bacteria.
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`Two ways in which to describe the administered amount of a tetracycline
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`compound is by daily dose, and by serum level.
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`Eor example, tetracycline compounds that have significant antibiotic activity
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`may be administered in a dose (i.e. amount) which is 10—80% of the antibiotic dose.
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`More preferably, the antibiotic tetracycline compound is administered in a dose which
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`is 40-70% of the antibiotic dose.
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`Some examples of antibiotic doses of members of the tetracycline family
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`include 50, 75, and 100 mg/day of doxycycline; 50, 75, 100, and 200 mg/day of
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`minocycline; 250 mg of tetracycline one, two, three, or four times a day; 1000 mg/day
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`of oxytetracycline}; 600 mg/day of demeclocycline; and 600 mg/day of lymecycline.
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`Examples of the maximum non-antibiotic doses of tetracyclines based on
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`steady—state pharmacokinetics are as follows: 20 mg/twice a day for doxycycline; 3 8
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`mg of minocycline one, two, three or four times a day; and 60 mg of tetracycline one,
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`two, three or four times a day.
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`In a preferred embodiment, to reduce the number of comedones, doxycycline
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`is administered in a daily amount of from about 30 to about 60 milligrams, but
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`maintains a concentration in human plasma below the threshold for a significant
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`antibiotic effect.
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`In an especially preferred embodiment, doxycycline hyclate is administered at
`
`a 20 milligram dose twice daily. Such a formulation is sold fer the treatment of
`
`periodontal disease by CollaGenex Pharmaceuticals, Inc. of Newtown, Pennsylvania
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`under the trademark Periostat ®.
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`Example 38 below summarizes a clinical study using 20 mg doxycycline
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`hyclate tablets administered twice a day. A significant reduction in the number of
`
`comedones was observed. This reduction in the number of comedones is unexpected.
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`The reduction is particularly unexpected since, as can be seen from the microbiology
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`results in Example 38, the treatment with doxycycline resulted in no reduction of skin
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`microflora vis—a—vis a placebo control.
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`The administered amount of a tetracycline compound described by serum
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`levels follows.
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`An antibiotic tetracycline compound is advantageously administered in an
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`amount that results in a serum tetracycline concentration which is 10—80% of the
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`minimum antibiotic serum concentration. The minimum antibiotic serum
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`concentration is the lowest concentration known to exert a significant antibiotic effect.
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`Some examples of the approximate antibiotic serum concentrations of
`
`members of the tetracycline family follow.
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`For example, a single dose of two 100 mg minocycline HCl tablets
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`administered to adult humans results in minocycline serum levels ranging from 0.74
`
`to 4.45 [Lg/ml over a period of an hour. The average level is 2.24 rug/ml.
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`Two hundred and fifty milligrams of tetracycline HCl administered every six
`
`hours over a twenty-four hour period produces a peak plasma concentration of
`
`approximately 3 ug/ml. Five hundred milligrams of tetracycline HCl administered
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`every six hours over a twenty—four hour period produces a serum concentration level
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`of 4 to 5 ,ug/ml.
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`In one embodiment, the tetracycline compound can be administered in an
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`amount which results in a serum concentration between about 0.1 and 10.0 rig/nil,
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`more preferably between 0.3 and 5.0 ug/ml. For example, doxycycline is
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`administered in an amount which results in a serum concentration between about 0.l
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`and 0.8 gag/ml, more preferably between 0.4 and 0.7 ug/ml.
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`Some examples of the plasma antibiotic threshold levels of tetracyclines based
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`on steady—state pharmacokinetics are as follows: 1.0 [lg/m1 for doxycycline; 0.8 ug/ml
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`for minocycline; and 0.5 ug/ml for tetracycline.
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`Non—antibiotic tetracycline compounds can be used in higher amounts than
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`antibiotic tetracyclines, While avoiding the indiscriminate killing of microbes, and the
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`emergence of resistant microbes. For example, 6—demethyl—6-deoxy—
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`4-de(dimethylamino)tetracycline (GMT—3) may be administered in doses of about 40
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`to about 200 mg/day, or in amounts that result in serum levels of about 1.55 pg/ml to
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`about 10 ug/ml.
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`The actual preferred amounts of tetracycline compounds in a specified case
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`Will vary according to the particular compositions formulated, the mode of
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`application, the particular sites of application, and the subject being treated.
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`The tetracycline compounds can be in the form of pharmaceutically acceptable
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`salts of the compounds. The term "pharmaceutically acceptable salt” refers to a salt
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`prepared from tetracycline compounds and pharmaceutically acceptable non—toxic
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`acids or bases. The acids may be inorganic or organic acids of tetracycline
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`compounds. Examples of inorganic acids include hydrochloric, hydrobromic,
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`hydroiodic, sulfuric, and phosphoric acids. Examples oforganic acids include
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`carboxylic and sulfonic acids. The radical of the organic acids may be aliphatic or
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`aromatic. Some examples of organic acids include formic, acetic, phenylacetic,
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`propionic, succinic, glycolic, glucuronic, maleic, furoic, glutamic, benzoic,
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`anthranilic, salicylic, phenylacetic, mandelic, embonic (pamoic), methanesulfonic,
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`ethanesulfonic, panthenoic, benzenesulfonic, stearic, sulfanilic, alginic, tartaric, citric,
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`gluconic, gulonic, arylsulfonic, and galacturonic acids. Appropriate organic bases
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`may be selected, for example, fi'om N,N~dibenzylethylenediamine, chloroprocaine,
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`choline, diethanolamine, ethylenediamine, meglumine (N-methy1glucamine)_, and
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`procaine.
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`The tetracycline compounds mentioned above, especially doxycycline and
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`minocycline, are unexpectedly effective in reducing the number of comedones when
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`administered at a dose which has substantially no antibiotic effect. Preferably the
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`reduction is at least about 20% greater than for a placebo control, more preferably at
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`least about 30% greater than for a placebo control, most preferably at least about 40%
`
`greater than for a placebo control, and optimally at least about 50% greater than for a
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`placebo control.
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`The inventors are not certain of, and do not wish to be limited by, any
`
`particular mechanism of action. Nevertheless, it is believed that the ability of
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`tetracyclines, such as doxycycline, to inhibit oxidation of melanin and to inhibit lipid—
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`associated abnormal folliCular differentiation prevents keratinocytes from becoming
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`cohesive, thereby inhibiting the formation of comedones.
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`Preferably, the tetracycline compounds have low phototoxicity, or are
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`administered in an amount that results in a serum level at which the phototoxicity is
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`acceptable. Phototoxicity is a chemically—induced photosensitivity. Such
`
`photosensitivity renders skin susceptible to damage, 6. g. sunburn, blisters, accelerated
`
`aging, erythemas and eczematoid lesions, upon exposure to light, in particular
`
`ultraviolet light. The preferred amount of the tetracycline compound produces no
`
`more phototoxicity than is produced by the administration of a 40 mg total daily dose
`
`of doxycycline.
`
`Phototoxicity can be evaluated in terms of a photoirritancy factor (PIP), as
`
`described in the examples. A PIF value of about 1.0 indicates that a compound is
`
`considered to have no measurable phototoxicity.
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`10
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`15
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`20
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`25
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`The low phototoxic derivatives preferably have PIP values no greater than
`
`about 5, preferably no greater than about 2, more preferably no greater than about 1.5,
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`30
`
`most preferably no greater than about 1.2, and optimally about 1.
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`Some antibiotic tetracyclines having low phototoxicity include, for example,
`
`minocyoline and tetracyline.
`
`Some non—antibiotic tetracyclines having low phototoxicity include, but are
`
`not limited to, tetracycline compounds having the general formulae:
`
`STRUCTURE K
`
`wherein: R7, R8, and R9 taken together in each case, have the following meanings:
`
`R7
`
`R8
`
`R9 ‘
`
`hydrogen
`hydrogen
`hydrogen
`“
`
`and
`
`hydrogen
`hydrogen
`hydrogen
`
`amino
`palmitamide
`dimethylamino
`
`STRUCTURE L
`
`STRUCTURE N
`
`STRUCTURE M
`
`STRUCTURE 0
`
`wherein: R7, R8, and R9 taken together in each case, have the following meanings:
`
`R7
`
`hydrogen
`hydrogen
`hydrogen
`hydrogen
`
`and
`
`R8
`
`’
`
`hydrogen
`hydrogen
`hydrogen
`hydrogen
`
`R9
`
`acetamido
`dimethylarninoacetamido
`nitro
`amino
`
`STRUCTURE P
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`10
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`15
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`20
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`25
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`30
`
`wherein: R8, and R9 taken together are, respectively, hydrogen and nitro.
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`35
`
`The tetracycline compounds are administered without administering a
`bisphosphonate compound. Bisphosphonates compounds are related to inorganic
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`pyrophosphonic acid. The bisphOSphonates include, as non—limiting examples,
`
`alendronate ((4—amino-l— hydroxybutylidene) bisphosphonic acid), clodronate
`
`(dichloromethane diphOSphonic acid), etidronate ((l-hydroxyethylidene) diphosphanic
`acid) and pamidronate ((3—amino-l- hydroxypropylidene) bisphosphonic acid); also
`
`risedronate ([—hydroxy-Z—(3—pyridinyl)ethylidene] bisphosphonic acid), tiludronate,
`
`i.e., tiludronic acid ([(4—chlorophenyl) thio] methylene] bisphosphonic acid) and
`
`zolendronate.
`
`‘ The tetracycline compounds may, for example, be administered systemically.
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`10
`
`For the purposes of this specification, “systemic administration” means administration
`
`to a human by a method that causes the compounds to be absorbed into the
`
`bloodstream.
`
`For example, the tetracyclines compounds can be administered orally by any
`
`15
`
`method known in the art. For example, oral administration can be by tablets,
`
`capsules, pills, troches, elixirs, suspensions, syrups, wafers, chewing gum and the
`
`like.
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`20
`
`25
`
`30
`
`Additionally, the tetracycline compounds can be administered enterally or
`
`parenterally, e.g., intravenously; intramuscularly; subcutaneously, as injectable
`
`solutions or suspensions; intraperitoneally; or rectally. Administration can also be
`
`intranasally, in the form of, for example, an intranasal spray; or transderrnally, in the
`
`form of, for example, a patch.
`
`For the pharmaceutical purposes described above, the tetracycline compounds
`
`of the invention can be formulated per se in pharmaceutical preparations optionally
`
`with a suitable pharmaceutical carrier (vehicle) or excipient as understood by
`practitioners in the art. These preparations can be made according to conventional
`
`chemical methods.
`
`In the case of tablets for oral use, carriers which are commonly used include
`
`lactose and corn starch, and lubricating agents such as magnesium stearate are
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`commonly added. For oral administration in capsule form, useful carriers include
`
`lactose and corn starch. Further examples of carriers and excipients include milk,
`
`sugar, certain types of clay, gelatin, stearic acid or salts thereof, calcium stearate, talc,
`
`vegetable fats or oils, gums and glycols.
`
`When aqueous suspensions are used for oral administration, emulsifying
`
`and/or suspending agents are commonly added. In addition, sweetening and/or
`
`flavoring agents may be added to the oral compositions.
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`10
`
`For intramuscular, intraperitoneal, subcutaneous and intravenous use, sterile
`
`solutions of the tetracycline compounds can be employed, and the pH of the solutions
`
`can be suitably adjusted and buffered. For intravenous use, the total concentration of
`
`the solute(s) can be controlled in order to render the preparation isotonic.
`
`15
`
`The tetracycline compounds of the present invention can further comprise one
`
`or more pharmaceutically acceptable additional ingredient(s) such as alum, stabilizers,
`
`buffers, coloring agents, flavoring agents, and the like.
`
`20
`
`25
`
`The tetracycline compound may be administered intermittently. For example,
`
`the tetracycline compound may be administered 1—6 times a day, preferably 1-4 times
`
`a day.
`
`Alternatively, the tetracycline compound may be administered by sustained
`
`release. Sustained release administration is a method of drug delivery to achieve a
`
`certain level of the drug over a particular period of time. The level. typically is
`
`measured by serum concentration. Further description of methods of delivering
`
`, tetracycline compounds by sustained release can be found in the patent application,
`
`“Controlled Delivery of Tetracycline and Tetracycline Derivatives,” filed on‘April 5,
`
`i 2001 and assigned to CollaGeneX Pharmaceuticals, Inc. ofNewtown, Pennsylvania.
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`30
`
`The aforementioned application is incorporated herein by reference in its entirety.
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`For example, 40 milligrams of doxycycline may be administered by sustained release
`
`over a 24 hour period.
`
`In the embodiment in which the tetracycline compound is a non-antibiotic
`
`tetracycline compound, administration can include topical application. Particular non—
`
`antibiotic tetracycline compounds have only limited biodistribution, e. g. GMT-5. In
`
`such cases, topical application is the preferred method of administration of the
`
`compound.
`
`Carrier compositions deemed to be suited for topical use include gels, salves,
`
`lotions, creams, ointnients and the like. The non—antibiotic tetracycline compound can
`
`also be incorporated with a support base or matrix or the like which can be directly
`
`applied to skin.
`
`TOpical application of non—antibiotic tetracycline compounds are effective in
`
`treating acne while not inducing significant toxicity in the human. For example,
`
`amounts of up to about 25% (w/w) in a vehicle are effective. Amounts of from about
`
`0.1% to about 10% are preferred.
`
`Combined or coordinated topical and systemic administration of the
`
`tetracycline compounds is also contemplated under the invention. For example, a
`
`non—absorbable non-antibiotic tetracycline compound can be administered topically,
`
`while a tetracycline compoundlcapable of substantial absorption and effective
`
`systemic distribution in a human can be administered systemically.
`
`.
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`10
`
`15
`
`20
`
`25
`
`The tetracycline compounds are prepared by methods known in the art. For
`example, natural tetracyclines may be modified without losing their antibiotic A
`properties, although certain elements of the structure must be retained. The
`
`modifications that may and may not be made to the basic tetracycline structure have
`
`30
`
`been reviewed by Mitscher in The Chemise}; of Tetracyclines, Chapter 6, Marcel
`
`Dekker, Publishers, New York (1978‘). According to Mitscher, the substituents at
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`positions 5—9 of the tetracycline ring system may be modified without the complete
`
`loss of antibiotic properties. Changes to the basic ring system or replacement of the
`
`substituents at positions 1-4 and 1012, however, generally lead to synthetic
`
`tetracyclines with substantially less or effectively no antibiotic activity.
`
`Further methods of preparing the tetracycline compounds are described in the
`
`examples.
`
`EXAMPLES
`
`The following examples serve to provide further appreciation of the invention
`
`but are not meant in any way to restrict the effective scope of the invention.
`
`Preparation of Compounds
`
`EXAMPLE 1
`
`4-Dedimethylamino-7-dimethylamino~6-demethyl-6-deoxy~9—nitrotetracycline sulfate
`
`To a solution of one millirnole of 4—dedimethylamino-7-dimethylamino—6-
`
`demethyl—6-deoxytetracycline in 25 ml of concentrated sulfuric acid at 0°C was added
`
`1.05 mmole of potassium nitrate. The resulting solution was stirred at ice bath
`
`temperature for 15 minutes and poured in one liter of cold ether with stifling. The
`
`precipitated solid was allowed to settle and the majority of solvent decanted. The
`
`remaining material was filtered through a sintered glass funnel and the collected solid
`
`was washed well with cold ether. The product was dried in a vacuum desiccator
`
`10
`
`15
`
`20
`
`25
`
`overnight.
`
`9—amino—4—dedimethylamino—7—dimethylarriino:6~demethyl~6—deoxytetracycline
`
`EXAMPLE 2
`
`30
`
`sulfate
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`To a solution of 300 mg of the 9—nitr0 compound from example 1, in 30 ml of
`
`ethanol was added 50 mg of Pt02. The mixture was hydrogenated at atmospheric
`
`pressure until the theoretical amount of hydrogen was absorbed. The system is
`
`flushed with nitrogen, the catalyst PtOz is filtered and the filtrate added dropwise to
`
`5
`
`300 ml of ether. The product that separates is filtered and dried in a vacuum
`
`desiccator:
`
`W
`
`9-Acetaniido~4—dedim