Patent Grant
7244441
The disclosed invention relates to stents or intra-luminal prosthesis coated with or otherwise containing a MAP kinase inhibitor such as a p38 MAP kinase inhibitor. MAP kinase inhibitor containing stents or intra-luminal prosthesis control, reduce, or prevent restenosis, inflammation, and complications associated with stent or intra-luminal prosthesis implantation and/or cardiovascular disease.
Coated Stents
The use of stents to hold open the lumens of blood vessels has become quite widespread. Although stents are recognized as being useful for holding open occluded blood vessels, including occluded coronary arteries, the successful use of stents is limited to a certain degree. For example, a significant degree of restenosis, inflammation, and cardiovascular disorders result from stent implantation.
Currently, attempts to improve the clinical performance of stents have involved some variation of either applying a coating to the metal of the stent (as discussed in U.S. Pat. No. 5,356,433, entitled, “Biocompatible metal surfaces” and U.S. Pat. No. 5,336,518, entitled, “Treatment of metallic surfaces using radiofrequency plasma deposition and chemical attachment of bioactive agents”, both of which are hereby incorporated by reference), attaching a covering or membrane, embedding material on the surface of the stent via ion bombardment, or including reservoirs in the design of the stent. In addition, certain therapeutic agents such as rapamycin or heparin are coated on stents.
One area in which stents are limited is with respect to inflammation that occurs at the lesion site. It would be useful in the field of stents to provide a stent that contains a therapeutic agent that control, reduce, or prevent restenosis, inflammation, and cardiovascular complications associated with stent implantation and/or cardiovascular disease.
Also encompassed in the invention is a method of treating a subject including providing a stent containing a MAP kinase inhibitor such as p38 kinase inhibitor to a subject.
The disclosed invention is directed to a stent or intra-luminal prosthesis comprising a MAP kinase inhibitor, preferably p38 kinase inhibitor, wherein the inhibitor is adhered thereto or integral therewith, and methods of making and using such a stent or intra-luminal prosthesis. In one preferred embodiment, the stent further comprises a strut containing at least one channel or well therein which contains the MAP kinase inhibitor. In another preferred embodiment, the coating is a dispersion or solution containing the MAP kinase inhibitor. The coating may also contain a polymer, for example, where the MAP kinase is distributed throughout. The stent or intra-luminal prosthesis itself may be bioabsorbable and have MAP kinase inhibitors coated thereon or distributed therethrough. Such stents or intra-luminal prosthesis may also comprise an additional active component such as rapamycin.
Also encompassed in the invention is a method of treating a subject, for example, one having an occluded blood vessel or cardiovascular disease, including implanting a stent or intra-luminal prosthesis containing a MAP kinase inhibitor such as p38 kinase inhibitor to a subject. Further, the invention is directed to a method of reducing restenosis and/or inflammation comprising implanting the stent or intra-luminal prosthesis in a blood vessel such as an artery of a subject, wherein the restenosis of the vessel resulting from implantation of the stent or intra-luminal prosthesis is less than that observed from implantation of a stent or intra-luminal prosthesis not comprising a MAP kinase inhibitor. The methods above are also applicable where the subject has a vulnerable plaque at a site other than the stent or intra-luminal prosthesis implantation. In one embodiment, inflammation at the site of implantation is reduced in comparison to that observed from an implantation of a stent or intra-luminal prosthesis not comprising a MAP kinase inhibitor. The invention also provides a method to treat plaque comprising implanting a stent or intra-luminal prosthesis of the invention in a blood vessel of a subject in need thereof.
This application describes compositions and methods for delivering a therapeutic agent using a stent or intra-luminal prosthesis. Specifically, a stent or intra-luminal prosthesis containing a MAP kinase inhibitor is placed at the diseased site in the vascular system such as within an artery. Stents that can be used in accordance with the invention may be cylindrical and perforated with passages that are slots, ovoid, circular or the like shape. Stents may also be composed of helically wound or serpentine wire structures in which the spaces between the wires form the passages. Stents may be flat perforated structures that are subsequently rolled to form tubular structures or cylindrical structures that are woven, wrapped, drilled, etched or cut to form passages. Examples of stents include but are not limited stents described in the following U.S. Pat. No. 4,733,665 (hereinafter the Palmaz stent); U.S. Pat. No. 4,800,882 (hereinafter the Gianturco stent); U.S. Pat. No. 4,886,062 (hereinafter the Wiktor stent) and U.S. Pat. No. 5,514,154 (hereinafter the Guidant RX Multilink™ stent). These stents can be made of biocompatible materials including biostable and bioabsorbable materials. Suitable biocompatible metals include, but are not limited to, stainless steel, tantalum, titanium alloys (including nitinol), and cobalt alloys (including cobalt-chromium-nickel alloys). Suitable bioabsorbable metallic stents, such as those produced by Biotronik are also contemplated. Suitable nonmetallic biocompatible materials include, but are not limited to, polyamides, polyolefins (i.e., bioabsorbable polymers such as polypropylene, polyethylene etc.), nonabsorbable polyesters (i.e., polyethylene terephthalate), poly (phosphoester) or polyamino carbonate, and bioabsorbable aliphatic polyesters (i.e., omopolymers and copolymers of lactic acid, glycolic acid, lactide, glycolide, para-dioxanone, trimethylene carbonate, ε-caprolactone, etc. and blends thereof), such as poly-L-lactic acid/glycolic acid. In addition, intraluminal prostheses may be used, e.g., those that are tubular in nature and are made from similar materials.
The invention provides for a biodegradable stent MAP kinase inhibitor delivery platform which in one aspect allows for time-dependent delivery of such drug. It also provides a method for delivery of MAP kinase inhibitors to treat multifocal and more diffuse diseases such as vulnerable plaques and peripheral vascular diseases, for example, diseases associated with superficial femoral artery (SFA) and abdominal aortic aneurism (AAA). Subjects with cardiovascular disease generally have vulnerable plaques in multiple locations throughout their coronary arteries and body. Thus, stents according to the invention, in one embodiment, induce MAP kinase mediated responses in subjects with cardiovascular diseases such as those having complex lesions exhibiting features of vulnerable plaques. Thus, the invention is useful for local therapy as well as systemic therapy.
Any MAP kinase, or preferably, p38 kinase, inhibitor may be used to coat or be distributed in a stent or intraluminal prosthesis. Preferred inhibitors of MAP kinase are disclosed in WO 00/12074, WO 99/61426, WO 02/46158, WO 00/71535, WO 0/59904, WO 00/12497, WO 02/042292, WO 2004/032874, and WO 2004/022712, all of which are incorporated herein in their entirety.
MAP Kinase
A large number of chronic and acute conditions have been recognized to be associated with perturbation of the inflammatory response. A large number of cytokines participate in this response, including interleukin 1 (IL-1), interleukin 6 (IL-6), interleukin 8 (IL-8) and tumor necrosis factor (TNF). It appears that the activity of these cytokines in the regulation of inflammation relies at least in part on the activation of an enzyme on the cell signaling pathway, a member of the MAP kinase family generally known as p38 and alternatively known as CSBP and RK. This kinase is activated by dual phosphorylation after stimulation by physiochemical stress, treatment with lipopolysaccharides or with proinflammatory cytokines such as IL-1 and TNF. Therefore, inhibitors of the kinase activity of p38 are useful anti-inflammatory agents.
PCT applications WO 98/06715, WO 98/07425, and WO 96/40143, all of which are incorporated herein by reference, describe the relationship of p38 kinase inhibitors with various disease states, including but not limited to cardiovascular diseases. As mentioned in these applications, inhibitors of p38 kinase are useful in treating a variety of diseases. The compounds disclosed in these applications are either imidazoles or are indoles substituted at the 3- or 4-position with a piperazine ring linked through a carboxamide linkage. Additional compounds which are conjugates of piperazines with indoles are described as insecticides in WO 97/26252, also incorporated herein by reference.
Indolyl substituted piperidines and piperazines which inhibit p38 kinase are described in PCT publication no. WO 99/61426 published 2 Dec. 1999. Certain aroyl/phenyl-substituted piperazines and piperidines which inhibit p38 kinase are described in PCT publication WO 00/12074 published 9 Mar. 2000. Carbolene derivatives of piperidine and piperazine as p38 inhibitors are described in WO 00/59904 published 12 Oct. 2000. Substituted piperidines and piperazines linked to an indole or indole derivative having a glyoxal group at the position corresponding to 2- or 3-position of indole that are used as p38 inhibitors is described in PCT publication WO 00/71535 published 30 Nov. 2000. Substituted piperidines and piperazines which are linked to an aryl group having a glyoxal substituent that are used for p38 inhibition are described in PCT publication WO 02/46158 published 13 Jun. 2002. Azaindole derivatives linked to a piperazine- or piperidine-type moiety used for p38 inhibition are described in WO 2004/032874 published Apr. 26, 2004. Indole derivatives substituted by an amine at position 1, coupled to piperazine- or piperidine-type moieties, are also useful in the apparatuses and methods of the invention as described in WO 2004/022712.
Quinazoline and quinazoline derivatives containing mandatory substituents at positions corresponding to the 2- and 4-positions of quinazoline that are used for p38 inhibitors are described in WO 00/12497 published on 9 Mar. 2000. Substituted piperazines and piperidines linked to an indole or indole derivative having a glyoxal substituent at the position corresponding to the 4-, 5-, 6-, or 7-position of indole which inhibit p38 kinase are described in PCT publication WO 02/042292 published 30 May 2002.
These quinazoline, piperidine and piperazine compounds are particularly useful in the context of the present invention.
It is contemplated that MAP kinase inhibitors include within their scope salts and cosalts, solvates and cosolvates, crystals and cocrystals or combinations thereof, of the components more specifically discussed herein. Examples of such variants may be found in Remington: The Science and Practice of Pharmacy (20th ed.) Lippincott, Williams & Wilkins (2000). When the compounds of the invention contain one or more chiral centers, the invention includes optically pure forms as well as mixtures of stereoisomers or enantiomers.
Exemplary Inhibitors
Compounds useful in the practice of the present invention include, but are not limited to, compounds of formula:
wherein
Exemplary compounds of this formula include:
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formula:
wherein
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formula:
wherein
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formulas:
wherein
Exemplary compounds of these formulas include:
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formulas:
wherein
Exemplary compounds of these formulas include:
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formula:
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formulas:
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formulas:
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formulas:
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formulas:
wherein
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formulas:
or pharmaceutically acceptable salts thereof, wherein
Compounds useful in the practice of the present invention also include, but are not limited to, compounds of formula:
wherein A is
wherein
or a pharmaceutically-acceptable salt thereof;
or
wherein
Exemplary compounds of these formulas include:
Such compounds are described in published PCT applications WO 96/21452, WO 96/40143, WO 97/25046, WO 97/35856, WO 98/25619, WO 98/56377, WO 98/57966, WO 99/32110, WO 99/32121, WO 99/32463, WO 99/61440, WO 99/64400, WO 00/10563, WO 00/17204, WO 00/19824, WO 00/41698, WO 00/64422, WO 00/71535, WO 01/38324, WO 01/64679, WO 01/66539, and WO 01/66540, each of which is herein incorporated by reference in their entirety.
In all instances herein where there is an alkenyl or alkynyl moiety as a substituent group, the unsaturated linkage, i.e., the vinylene or acetylene linkage, is preferably not directly attached to the nitrogen, oxygen or sulfur moieties, for instance in ORf, or for certain R2 moieties.
As used herein, “optionally substituted” unless specifically defined shall mean such groups as halogen, such as fluorine, chlorine, bromine or iodine; hydroxy; hydroxy-substituted C1-10alkyl; C1-10 alkoxy, such as methoxy or ethoxy; S(O)m alkyl, wherein m is 0, 1 or 2, such as methyl thio, methylsulfinyl or methyl sulfonyl; amino, mono and di-substituted amino, such as in the NR7R17 group; or where the R7R17 can together with the nitrogen to which they are attached cyclize to form a 5- to 7-membered ring which optionally includes an additional heteroatom selected from O, N, and S; C1-10 alkyl, cycloalkyl, or cycloalkyl alkyl group, such as methyl, ethyl, propyl, isopropyl, t-butyl, etc. or cyclopropyl methyl; halo-substituted C1-10 alkyl, such as CF3; an optionally substituted aryl, such as phenyl, or an optionally substituted arylalkyl, such as benzyl or phenethyl, wherein these aryl moieties can also be substituted one to two times by halogen; hydroxy; hydroxy-substituted alkyl; C1-10 alkoxy; S(O)m alkyl; amino, mono- and di-substituted amino, such as in the NR7R17 group; alkyl, or CF3.
Inhibitors useful in the present invention can be used with any pharmaceutically acceptable salt. The term “pharmaceutically acceptable salts” refers to salts prepared from pharmaceutically acceptable non-toxic bases or acids. When the compound utilized by the present invention is acidic, its corresponding salt can be conveniently prepared from pharmaceutically acceptable non-toxic bases, including inorganic bases and organic bases. Salts derived from such inorganic bases include aluminum, ammonium, calcium, copper (ic and ous), ferric, ferrous, lithium, magnesium, manganese (ic and ous), potassium, sodium, zinc and the like salts. Particularly preferred are the ammonium, calcium, magnesium, potassium and sodium salts. Salts derived from pharmaceutically acceptable organic non-toxic bases include salts of primary, secondary, and tertiary amines, as well as cyclic amines and substituted amines such as naturally occurring and synthesized substituted amines. Basic salts of inorganic and organic acids also include as hydrochloric acid, hydrobromic acid, sulphuric acid, phosphoric acid, methane sulphonic acid, ethane sulphonic acid, acetic acid, malic acid, tartaric acid, citric acid, lactic acid, oxalic acid, succinic acid, fumaric acid, maleic acid, benzoic acid, salicylic acid, phenylacetic acid and mandelic acid. In addition, pharmaceutically-acceptable salts of the above-described compounds can also be formed with a pharmaceutically-acceptable cation, for instance, if a substituent group comprises a carboxy moiety. Suitable pharmaceutically-acceptable cations are well known to those skilled in the art and include alkaline, alkaline earth, ammonium and quaternary ammonium cations.
Other pharmaceutically acceptable organic non-toxic bases from which salts can be formed include ion exchange resins such as, for example, arginine, betaine, caffeine, choline, N,N-dibenzylethylenediamine, diethylamine, 2-diethylaminoethanol, 2-dimethylaminoethanol, ethanolamine, ethylenediamine, N-ethylmorpholine, N-ethylpiperidine, glucamine, glucosamine, histidine, hydrabamine, isopropylamine, lysine, methylglucamine, morpholine, piperazine, piperidine, polyamine resins, procaine, purines, theobromine, triethylamine, trimethylamine, tripropylamine, tromethamine and the like. Synthesis of the disclosed compounds is discussed in U.S. patent application Ser. No. 09/575,060, which is hereby incorporated by reference in its entirety.
The inhibitors of MAP kinase such as p38 can be used as a single therapeutic agent in a stent or intra-luminal prosthesis of the invention or in combination with other therapeutic agents. Drugs that could be usefully combined with these compounds include monoclonal antibodies targeting cells of the immune system, antibodies or soluble receptors or receptor fusion proteins targeting immune or non-immune cytokines, and small molecule inhibitors of cell division, protein synthesis, or mRNA transcription or translation, or inhibitors of immune cell differentiation, activation, or function (e.g., cytokine secretion). Additionally, compounds that inhibit cell growth or generally inhibit restenosis are contemplated for use with the claimed invention. Examples of such technology include heparin-coated stents, sirolimus-eluting stents, paclitaxol-coated stents, and the like.
The following terms, as used herein, refer to:
For the purposes herein the “core” 4-pyrimidinyl moiety for R1 or R2 is referred to as the formula:
The compounds useful in the practice of the present invention can contain one or more asymmetric carbon atoms and can exist in racemic and optically active forms. The use of all of these compounds are included within the scope of the present invention.
Compounds useful in the practice of the present invention also include, but are not limited to, the compounds shown in Tables A and B, below.
The compounds described above are provided for guidance and exemplary purposes only. It should be understood that any modulator of p38 MAP kinase is useful for the invention provided that it exhibits adequate activity relative to the targeted protein. Alternative modulators of p38 MAP kinase activity, such as antibodies or functional fragments thereof are also contemplated for use in the claimed invention. Preferred modulators useful for the invention should be adequately active against p38 MAP kinase while being compatible with stent coating and applications. Variables to take into consideration should include stent composition, structure, and use, coating methods and techniques, other manufacturing processes including exposure to solvents and relevant chemistries, shelf life, stability, safety, efficacy, pharmokinetics, pharmacodynamics and the like.
Coating Stents or Intra-Luminal Prostheses
One approach to coating stents or intra-luminal prostheses is to incorporate the MAP kinase inhibitor into a polymer material which is then coated on the stent or intra-luminal prosthesis. Such polymer coatings are known in the art such as that discussed in U.S. Pat. Nos. 6,153,252 and 6,364,903. Examples of such polymers include elastomers such as an ε-caprolactone and glycolide copolymer, polytetrafluoroethylene (PTFE), expanded PTFE (ePTFE), polyurethane, fluorinated ethylene propylene (FEP), silicone, polyurethane-acrylate, silicone-acrylate, urethanesilicone, and the like. Combinations of these polymers may also be usefufl. Portions of the stent or intra-luminal prosthesis may also be coated with different polymers.
In addition, film-forming polymers that can be used for coatings in this application can be absorbable or non-absorbable and should be biocompatible to minimize irritation to the vessel wall. The polymer may be either biostable or bioabsorbable depending on the desired rate of release or the desired degree of polymer stability, but a bioabsorbable polymer is preferred since, unlike biostable polymer, it will not be present long after implantation to cause any adverse, chronic local response. Furthermore, bioabsorbable polymers do not present the risk that over extended periods of time there could be an adhesion loss between the stent or intra-luminal prosthesis and coating caused by the stresses of the biological environment that could dislodge the coating and introduce further problems even after the stent is encapsulated in tissue.
Suitable film-forming bioabsorbable polymers that could be used include polymers selected from the group consisting of aliphatic polyesters, poly(amino acids), copoly(ether-esters), polyalkylenes oxalates, polyamides, poly(iminocarbonates), polyorthoesters, polyoxaesters, polyamidoesters, polyoxaesters containing amido groups, poly(anhydrides), polyphosphazenes, biomolecules and blends thereof. For the purpose of this invention aliphatic polyesters include homopolymers and copolymers of lactide (which includes lactic acid d-,1- and meso lactide), ε-caprolactone, glycolide (including glycolic acid), hydroxybutyrate, hydroxyvalerate, para-dioxanone, trimethylene carbonate (and its alkyl derivatives), 1,4-dioxepan-2-one, 1,5-dioxepan-2-one, 6,6-dimethyl-1,4-dioxan-2-one and polymer blends thereof. Poly(iminocarbonate) for the purpose of this invention include as described by Kemnitzer and Kohn, in the Handbook of Biodegradable Polymers, edited by Domb, Kost and Wisemen, Hardwood Academic Press, 1997, pages 251–272. Copoly(ether-esters) for the purpose of this invention include those copolyester-ethers described in Journal of Biomaterials Research, Vol. 22, pages 993–1009, 1988 by Cohn and Younes and Cohn, Polymer Preprints (ACS Division of Polymer Chemistry) Vol. 30(1), page 498, 1989 (e.g., PEO/PLA). Polyalkylene oxalates for the purpose of this invention include U.S. Pat. Nos. 4,208,511; 4,141,087; 4,130,639; 4,140,678; 4,105,034; and 4,205,399 (incorporated by reference herein). Polyphosphazenes, co-, ter- and higher order mixed monomer based polymers made from L-lactide, D, L-lactide, lactic acid, glycolide, glycolic acid, para-dioxanone, trimethylene carbonate and ε-caprolactone such as are described by Allcock in The Encyclopedia of Polymer Science, Vol. 13, pages 31–41, Wiley Intersciences, John Wiley & Sons, 1988 and by Vandorpe, Schacht, Dejardin and Lemmouchi in the Handbook of Biodegradable Polymers, edited by Domb, Kost and Wisemen, Hardwood Academic Press, 1997, pages 161–182 (which are hereby incorporated by reference herein). Polyanhydrides from diacids of the form HOOC—C6H4—O—(CH2)m—O—C6H4—COOH where m is an integer in the range of from 2 to 8 and copolymers thereof with aliphatic alpha-omega diacids of up to 12 carbons. Polyoxaesters polyoxaamides and polyoxaesters containing amines and/or amido groups are described in one or more of the following U.S. Pat. Nos. 5,464,929; 5,595,751; 5,597,579; 5,607,687; 5,618,552; 5,620,698; 5,645,850; 5,648,088; 5,698,213 and 5,700,583; (which are incorporated herein by reference). Polyorthoesters such as those described by Heller in Handbook of Biodegradable Polymers, edited by Domb, Kost and Wisemen, Hardwood Academic Press, 1997, pages 99–118 (hereby incorporated herein by reference). Film-forming polymeric biomolecules for the purpose of this invention include naturally occurring materials that may be enzymatically degraded in the human body or are hydrolytically unstable in the human body such as fibrin, fibrinogen, collagen, elastin, and absorbable biocompatable polysaccharides such as chitosan, starch, fatty acids (and esters thereof), glucoso-glycans and hyaluronic acid.
Suitable film-forming biostable polymers with relatively low chronic tissue response, such as polyurethanes, silicones, poly(meth)acrylates, polyesters, polyalkyl oxides (polyethylene oxide), polyvinyl alcohols, polyethylene glycols and polyvinyl pyrrolidone, as well as, hydrogels such as those formed from crosslinked polyvinyl pyrrolidinone and polyesters could also be used. Other polymers could also be used if they can be dissolved, cured or polymerized on the stent or intra-luminal prosthesis. These include polyolefins, polyisobutylene and ethylene-alphaolefin copolymers; acrylic polymers (including methacrylate) and copolymers, vinyl halide polymers and copolymers, such as polyvinyl chloride; polyvinyl ethers, such as polyvinyl methyl ether; polyvinylidene halides such as polyvinylidene fluoride and polyvinylidene chloride; polyacrylonitrile, polyvinyl ketones; polyvinyl aromatics such as polystyrene; polyvinyl esters such as polyvinyl acetate; copolymers of vinyl monomers with each other and olefins, such as etheylene-methyl methacrylate copolymers, acrylonitrile-styrene copolymers, ABS resins and ethylene-vinyl acetate copolymers; polyamides, such as Nylon 66 and polycaprolactam; alkyd resins; polycarbonates; polyoxymethylenes; polyimides; polyethers; epoxy resins, polyurethanes; rayon; rayon-triacetate, cellulose, cellulose acetate, cellulose acetate butyrate; cellophane; cellulose nitrate; cellulose propionate; cellulose ethers (i.e. carboxymethyl cellulose and hydoxyalkyl celluloses); and combinations thereof. Polyamides for the purpose of this application would also include polyamides of the form —NH—(CH2)n—CO—and NH—(CH2)x—NH—CO—(CH2)y—CO, wherein n is preferably an integer in from 6 to 13; x is an integer in the range of form 6 to 12; and y is an integer in the range of from 4 to 16. The list provided above is illustrative but not limiting.
The polymers used for coatings preferably are film-forming polymers that have molecular weight high enough as to not be waxy or tacky. The polymers also should adhere to the stent and not be so readily deformable after deposition on the stent as to be able to be displaced by hemodynamic stresses. The polymers molecular weight be high enough to provide sufficient toughness so that the polymers will not to be rubbed off during handling or deployment of the stent and should not crack during expansion of the stent. The melting point of the polymer used in the present invention should have a melting temperature above 40° C., preferably above about 45° C., more preferably above 50° C. and most preferably above 55° C.
The preferable embodiment includes bioabsorbable elastomers, more preferably aliphatic polyester elastomers. In the proper proportions aliphatic polyester copolymers are elastomers. Elastomers present the advantage that they tend to adhere well to the metal stents and can withstand significant deformation without cracking. The high elongation and good adhesion provide superior performance to other polymer coatings when the coated stent is expanded. Examples of suitable bioabsorbable elastomers are described in U.S. Pat. No. 5,468,253 hereby incorporated by reference. Preferably the bioabsorbable biocompatible elastomers based on aliphatic polyester, including but not limited to those selected from the group consisting of elastomeric copolymers of ε-caprolactone and glycolide (preferably having a mole ratio of ε-caprolactone to glycolide of from about 35:65 to about 65:35, more preferably 45:55 to 35:65) elastomeric copolymers of ε-caprolactone and lactide, including L-lactide, D-lactide blends thereof or lactic acid copolymers (preferably having a mole ratio of ε-caprolactone to lactide of from about 35:65 to about 90:10 and more preferably from about 35:65 to about 65:35 and most preferably from about 45:55 to 30:70 or from about 90:10 to about 80:20) elastomeric copolymers of p-dioxanone (1,4-dioxan-2-one) and lactide including L-lactide, D-lactide and lactic acid (preferably having a mole ratio of p-dioxanone to lactide of from about 40:60 to about 60:40) elastomeric copolymers of ε-caprolactone and p-dioxanone (preferably having a mole ratio of ε-caprolactone to p-dioxanone of from about 30:70 to about 70:30) elastomeric copolymers of p-dioxanone and trimethylene carbonate (preferably having a mole ratio of p-dioxanone to trimethylene carbonate of from about 30:70 to about 70:30), elastomeric copolymers of trimethylene carbonate and glycolide (preferably having a mole ratio of trimethylene carbonate to glycolide of from about 30:70 to about 70:30), elastomeric copolymer of trimethylene carbonate and lactide including L-lactide, D-lactide, blends thereof or lactic acid copolymers (preferably having a mole ratio of trimethylene carbonate to lactide of from about 30:70 to about 70:30) and blends thereof. As is well known in the art these aliphatic polyester copolymers have different hydrolysis rates, therefore, the choice of elastomer may in part be based on the requirements for the coatings adsorption. For example ε-caprolactone-co-glycolide copolymer (45:55 mole percent, respectively) films lose 90% of their initial strength after 2 weeks in simulated physiological buffer whereas the ε-caprolactone-co-lactide copolymers (40:60 mole percent, respectively) loses all of its strength between 12 and 16 weeks in the same buffer. Mixtures of the fast hydrolyzing and slow hydrolyzing polymers can be used to adjust the time of strength retention.
In one embodiment, the PLGA class of polymers preferably have an inherent viscosity of from about 1.0 dL/g to about 4 dL/g, preferably an inherent viscosity of from about 1.0 dL/g to about 2 dL/g and most preferably an inherent viscosity of from about 1.2 dL/g to about 2 dL/g as determined at 25° C. in a 0.1 gram per deciliter (g/dL) solution of polymer in hexafluoroisopropanol (HFIP).
The solvent is chosen such that there is the proper balance of viscosity, deposition level of the polymer, solubility of the MAP kinase inhibitor, wetting of the stent or intra-luminal prosthesis and evaporation rate of the solvent to properly coat the stent or intra-luminal prosthesis. In the preferred embodiment, the solvent is chosen such the MAP kinase inhibitor and the polymer are both soluble in the solvent. In some cases, the solvent should be chosen such that the coating polymer is soluble in the solvent and such that MAP kinase inhibitor is dispersed in the polymer solution in the solvent. In that case the solvent chosen should be able to suspend small particles of the MAP kinase inhibitor without causing them to aggregate or agglomerate into collections of particles that would clog the slots of the stent when applied. Although the goal is to dry the solvent completely from the coating during processing, it is a great advantage for the solvent to be non-toxic, non-carcinogenic and environmentally benign. Mixed solvent systems can also be used to control viscosity and evaporation rates. In all cases, the solvent should not react with or inactivate the MAP kinase inhibitor or react with the coating polymer. Preferred solvents include by are not limited to: acetone, N-methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), toluene, methylene chloride, chloroform, 1,1,2-trichloroethane (TCE), various freons, dioxane, ethyl acetate, tetrahydrofuran (THF), dimethylformamide (DMF), and dimethylacetamide (DMAC).
The film-forming biocompatible polymer coatings are generally applied to reduce local turbulence in blood flow through the stent, as well as, adverse tissue reactions. The coating may also be used to administer a pharmaceutically active material to the site of the stents placement. Generally, the amount of polymer coating to be placed on the stent will vary with the polymer and the stent design and the desired effect of the coating. As a guideline the amount of coating may range from about 0.5 to about 20 as a percent of the total weight of the stent or intra-luminal prosthesis after coating and preferably will range from about 1 to about 15 percent. The polymer coatings may be applied in one or more coating steps depending on the amount of polymer to be applied. Different polymers may also be used for different layers in the stent coating. In fact it is highly advantageous to use a dilute first coating solution as primer to promote adhesion of a subsequent coating layers that may contain pharmaceutically active materials.
Additionally, a diffusion barrier can be applied to modulate the release of the MAP kinase inhibitor, or they could be used as the matrix for the delivery of a different pharmaceutically active material. The amount of release regulating layer on the stent or intra-luminal prosthesis may vary, but will generally be less than about 2000 μg preferably the amount of release regulating layer will be in the range of about 10 μg to about 1700 μg and most preferably in the range of from about 100 μg to about 500 μg. Layering of coating of fast and slow hydrolyzing copolymers can be used to stage release of the drug or to control release of different agents placed in different layers. Polymer blends may also be used to control the release rate of different agents or to provide desirable balance of coating (i.e. elasticity, toughness etc.) and drug delivery characteristics (release profile). Polymers with different solubilities in solvents can be used to build up different polymer layers that may be used to deliver different drugs or control the release profile of a drug. For example since ε-caprolactone-co-lactide elastomers are soluble in ethyl acetate and ε-caprolactone-co-glycolide elastomers are not soluble in ethyl acetate. A first layer of ε-caprolactone-co-glycolide elastomer containing a drug can be over coated with ε-caprolactone-co-lactide elastomer using a coating solution made with ethyl acetate as the solvent. Additionally, different monomer ratios within a copolymer, polymer structure or molecular weights may result in different solubilities. For example, 45/55 ε-caprolactone-co-glycolide at room temperature is soluble in acetone whereas a similar molecular weight copolymer of 35/65 ε-caprolactone-co-glycolide is substantially insoluble within a 4 weight percent solution. The second coating (or multiple additional coatings) can be used as a top coating to delay the drug deliver of the drug contained in the first layer. Alternatively, the second layer could contain a different drug to provide for sequential drug delivery. Multiple layers of different drugs could be provided by alternating layers of first one polymer then the other. As will be readily appreciated by those skilled in the art numerous layering approaches can be used to provide the desired drug delivery.
Coating may be formulated by mixing or applying a MAP kinase inhibitor with one or more therapeutic agents with the coating polymers in a coating mixture. The therapeutic agent may be present as a liquid, a finely divided solid, or any other appropriate physical form. Optionally, the mixture may include one or more additives, e.g., nontoxic auxiliary substances such as diluents, carriers, excipients, stabilizers or the like. Other suitable additives may be formulated with the polymer and MAP kinase inhibitor or compound. For example hydrophilic polymers selected from the previously described lists of biocompatible film forming polymers may be added to a biocompatible hydrophobic coating to modify the release profile (or a hydrophobic polymer may be added to a hydrophilic coating to modify the release profile). One example would be adding a hydrophilic polymer selected from the group consisting of polyethylene oxide, polyvinyl pyrrolidone, polyethylene glycol, carboxylmethyl cellulose, hydroxymethyl cellulose and combination thereof to an aliphatic polyester coating to modify the release profile. Appropriate relative amounts can be determined by monitoring the in vitro and/or in vivo release profiles for the therapeutic agents.
In a preferred embodiment, the coating application is performed using a solvent common to the polymer and MAP kinase inhibitor. This provides a wet coating that is a true solution. Less desirable, yet still useable are coatings that contain the MAP kinase inhibitor as a solid dispersion in a solution of the polymer in solvent. Under the dispersion conditions, preferably the particle size of the dispersed MAP kinase inhibitor powder, both the primary powder size and its aggregates and agglomerates, is small enough not to cause an irregular coating surface or to clog the slots of the stent that need to be kept coating-free. In cases where a dispersion is applied to the stent for improved smoothness of the coating surface or to ensure that all particles of the drug are fully encapsulated in the polymer, or in cases where slowing the release rate of the drug is preferable, deposited either from dispersion or solution, a clear (i.e. polymer only) top coat of the same polymer may be used to provide sustained release of the drug or another polymer that further restricts the diffusion of the drug out of the coating. The top coat can be applied by dip coating with mandrel or by spray coating (loss of coating during spray application is preferable for the clear topcoat since the MAP kinase inhibitor is not included). Dip coating of the top coat can be problematic if the MAP kinase inhibitor is more soluble in the coating solvent than the polymer and the clear coating redissolves previously deposited MAP kinase inhibitor. The time spent in the dip bath may need to be limited so that the MAP kinase inhibitor is not extracted out into the MAP kinase inhibitor-free bath. Drying should be rapid so that the previously deposited MAP kinase inhibitor does not completely diffuse into the topcoat.
The amount of MAP kinase inhibitor will be dependent upon the particular MAP kinase inhibitor employed, medical condition being treated and the amount of inflammation present. Typically, the amount of MAP kinase inhibitor represents about 0.001% to about 70%, more typically about 0.001% to about 60%, most typically about 0.001% to about 45% by weight of the coating.
The quantity and type of polymers employed in the coating layer containing the MAP kinase inhibitor in one embodiment of the invention will vary depending on the release profile desired and the amount of MAP kinase employed. The product may contain blends of the same or different polymers having different molecular weights to provide the desired release profile or consistency to a given formulation.
Absorbable polymers upon contact with body fluids including blood or the like, undergoes gradual degradation (mainly through hydrolysis) with concomitant release of the dispersed drug for a sustained or extended period (as compared to the release from an isotonic saline solution). Nonabsorbable and absorbable polymers may release dispersed drug by diffusion. This can result in prolonged delivery (about 1 to 2,000 hours, preferably 2 to 800 hours) of effective amounts (about 0.001 μg/cm2-min to 100 μg/cm2-min) of the drug. The dosage can be tailored to the subject being treated, the severity of the affliction, the judgment of the prescribing physician, and the like.
Individual formulations of drugs and polymers may be tested in appropriate in vitro and in vivo models to achieve the desired drug release profiles. For example, a drug could be formulated with a polymer (or blend) coated on a stent and placed in an agitated or circulating fluid system (such as PBS 4% bovine albumin). Samples of the circulating fluid could be taken to determine the release profile (such as by HPLC). The release of a MAP kinase inhibitor from a stent coating into the interior wall of a lumen could be modeled in appropriate porcine system. The drug release profile could then be monitored by appropriate means such as, by taking samples at specific times and assaying the samples for drug concentration (using HPLC to detect drug concentration). Thrombus formation can be modeled in animal models using the 111In-platelet imaging methods described by Hanson and Harker, Proc. Natl. Acad. Sci. USA 85:3184–3188 (1988). Following this or similar procedures, those skilled in the art will be able to formulate a variety of stent coating formulations.
In a preferred embodiment, the coating material must be able to adhere strongly to the metal stent or intra-luminal prosthesis both before and after expansion, be capable of retaining the drug at a sufficient load level to obtain the required dose, be able to release the drug in a controlled way over a period of several weeks, and be as thin as possible so as to minimize the increase in profile. In addition, the coating material preferably should not contribute to any adverse response by the body (i.e., should non-thrombogenic, non-inflammatory, etc.)
The polymeric coating may be applied to the stent or intra-luminal prosthesis using a number of different techniques. Two preferred examples of application of polymer coating include spraying the stent with a spray of polymer such as PTFE particles or dip coating the stent in a mixture containing PTFE particles. Powder coating generally refers to a variety of methods employing powdered plastics and resins which are used commercially to apply coatings to various articles. These methods include fluidized bed, electrostatic spray, electrostatic fluidized bed, plasma spray, and hot flocking, as well as combinations and variants of these methods.
In the electrostatic spray process, a coating powder is withdrawn from a reservoir in an air stream and electrostatically charged in the high voltage corona field of a spray gun. The charged particles are attracted to the grounded metal object to be coated and adhere to it by electrostatic attraction. The coated substrate is then placed in an oven and the coating is fused to form a substantially continuous film. The discrete polymers such as PTFE particles form a connected path around the stent. The relatively high viscosity of the PTFE melt serves to effectuate a superior coating. If the powder is sprayed on a preheated article, the powder melts and fuses directly on the hot surface; further heating to fuse or cure the coating may be required, depending upon the type of coating powder.
Plasma coating is a method comprising establishing a hot temperature plasma in an inert gas such as nitrogen, and the coating powder is introduced at the periphery of the plasma. The particles melt and are propelled at high velocity to the substrate, where they form a film. In hot flocking techniques, powders are usually dispersed in air and sprayed or blown onto the preheated substrate, where they melt and form a coating. In a variant of this process, small parts are preheated and dropped into a bed of powder kept in a mobile state by vibration. In this method, the parts are completely coated with an unfused layer of powder on the surface.
Another method for coating the stent or intra-luminal prosthesis is to suspend stent in the air, such as, on a hook, and spray the polymeric coating onto the stent according to the electrostatic spray method mentioned above. An advantage of applying the powder coating in this manner, is that it would sufficiently coat the stent in its entirety, and thus provide improved adhesion at its mating surface to the graft.
In another preferred embodiment, the stent can contain reservoirs which could be loaded with the MAP kinase inhibitor. A coating or membrane of biocompatable material could be applied over the reservoirs which would control the diffusion of the MAP kinase inhibitor from the reservoirs to the artery wall. One advantage of this system is that the properties of the coating can be optimized for achieving superior biocompatibility and adhesion properties, without the addition requirement of being able to load and release the drug. The size, shape, position, and number of reservoirs can be used to control the amount of drug, and therefore the dose delivered.
Delivery methods can vary. MAP kinase inhibitors such as a p38 kinase inhibitor can be delivered locally from the struts of a stent, from a stent graft, grafts, stent cover or sheath. In addition, delivery can involve a comixture with polymers (both degradable and nondegrading) to hold the MAP kinase inhibitor to the stent or graft. In addition the drug could be entrapped into the metal of the stent or intra-luminal prosthesis or graft body which has been modified to contain micropores or channels, as discussed in U.S. Pat. No. 6,273,913. In addition, the MAP kinase inhibitor can be covalently bound to the stent or intra-luminal prosthesis via solution chemistry techniques (such as via the Carmeda process) or dry chemistry techniques (e.g., vapor deposition methods such as rf-plasma polymerization) and combinations thereof. In addition, the delivery method could include catheter delivery intravascularly from a tandem balloon or a porous balloon for intramural uptake, extravascular delivery by the pericardial route, extravascular delivery by the advential application of sustained release formulations.
In addition, it is contemplated that another drug may also be coated onto the stent, such as heparin as described in U.S. Pat. No. 5,876,433, or another drug such as rapamycin or other immunosuppressive drug, or another anti-inflammatory drug.
As implied above, although the compounds of the invention may be used in humans, they are also available in treating animal subjects such as mammals. Stents of the invention may be used in a similar fashion as coated or uncoated stents as known in the art.
All of the references listed herein are incorporated herein by reference. The following examples are intended to illustrate but not to limit the invention.
The compounds to be tested are solubilized in DMSO and diluted into water to the desired concentrations. The p38 kinase is diluted to 10 μg/ml into a buffer containing 20 mM MOPS, pH 7.0, 25 mM beta-glycerol phosphate, 2 mg/ml gelatin, 0.5 mM EGTA, and 4 mM DTT.
The reaction is carried out by mixing 20 μl test compound with 10 μl of a substrate cocktail containing 500 μg/ml peptide substrate and 0.2 mM ATP (+200 μCi/ml gamma-32P-ATP) in a 4× assay buffer. The reaction is initiated by the addition of 10 μl of p38 kinase. Final assay conditions are 25 mM MOPS, pH 7.0, 26.25 mM beta-glycerol phosphate, 80 mM KCI, 22 mM MgCl2, 3 mM MgSO4, 1 mg/ml gelatin, 0.625 mM EGTA, 1 mM DTT, 125 μg/ml peptide substrate, 50 μM ATP, and 2.5 μg/ml enzyme. After a 40 minute incubation at room temperature, the reaction is stopped by the addition of 10 μl per reaction of 0.25 M phosphoric acid.
A portion of the reaction is spotted onto a disk of P81 phosphocellulose paper, the filters are dried for 2 minutes and then washed 4× in 75 mM H3PO4. The filters are rinsed briefly in 95% ethanol, dried, then placed in scintillation vials with liquid scintillation cocktail.
Alternatively, the substrate is previously biotinylated and the resulting reactions are spotted on SAM2™ streptavidin filter squares (Promega). The filters are washed 4× in 2M NaCl, 4× in 2M NaCl with 1% phosphoric acid, 2× in water, and briefly in 95% ethanol. The filter squares are dried and placed in scintillation vials with liquid scintillation cocktail.
Counts incorporated are determined on a scintillation counter. Relative enzyme activity is calculated by subtracting background counts (counts measured in the absence of enzyme) from each result, and comparing the resulting counts to those obtained in the absence of inhibitor.
IC50 values are determined with curve-fitting plots available with common software packages. Approximate IC50 values were calculated using formula:
IC50(app)=A×i/(1−A)
where A=fractional activity and i=total inhibitor concentration.
Venous blood is collected from healthy male volunteers into a heparinized syringe and is used within 2 hours of collection. Test compounds are dissolved in 100% DMSO and 1 μl aliquots of drug concentrations ranging from 0 to 1 mM are dispensed into quadruplicate wells of a 24-well microtiter plate (Nunclon Delta SI, Applied Scientific, So. San Francisco, Calif.). Whole blood is added at a volume of 1 ml/well and the mixture is incubated for 15 minutes with constant shaking (Titer Plate Shaker, Lab-Line Instruments, Inc., Melrose Park, Ill.) at a humidified atmosphere of 5% CO2 at 37° C. Whole blood is cultured either undiluted or at a final dilution of 1:10 with RPMI 1640 (Gibco 31800+NaHCO3, Life Technologies, Rockville, Md. and Scios, Inc., Sunnyvale, Calif.). At the end of the incubation period, 10 μl of LPS (E. coli 0111:B4, Sigma Chemical Co., St. Louis, Mo.) is added to each well to a final concentration of 1 or 0.1 μg/ml for undiluted or 1:10 diluted whole blood, respectively. The incubation is continued for an additional 2 hours. The reaction is stopped by placing the microtiter plates in an ice bath and plasma or cell-free supernates are collected by centrifugation at 3000 rpm for 10 minutes at 4° C. The plasma samples are stored at −80° C. until assayed for TNF-α levels by ELISA, following the directions supplied by Quantikine Human TNF-α assay kit (R&D Systems, Minneapolis, Minn.).
According to the assays in Examples 1 and/or 2, the compounds in Table B exhibit an IC50 relative to p38 kinase of less than 5 μM.
The effect of p38 MAP kinase inhibitor coated stents on restenosis in a porcine model is studied. Eight normolipemic pigs undergo coronary angiography and segments of the left anterior descending and left circumflex arteries are selected as targets for stent implantation. A p38 MAP kinase inhibitor selected from Table B is used to coat 3.5-mm tantalum stents. The p38 MAP kinase inhibitor coated stents are implanted in both arteries of four test pigs. Uncoated stents are implanted into the arteries of four control pigs. Stent-to-artery ratio is similar in the coated stent arteries and the control arteries. Animals are administered 325 mg aspirin daily and are killed at 28 days. The intimal area is significantly reduced in the coated stent arteries as compared with control arteries treated with stent only. This experimental procedure can be used to determine the ability of any p38 MAP kinase to inhibit restenosis.
Modifications of the above-described modes for carrying out the invention that are obvious to persons of skill in the art are intended to be within the scope of the following claims. All publications, patents, and patent applications cited in this specification are incorporated herein by reference as if each such publication, patent or patent application were specifically and individually indicated to be incorporated herein by reference.
This application claims priority to U.S. provisional application 60/506,216 filed Sep. 25, 2003. The contents of this document are incorporated herein by reference.
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