WO2005049021A1

WO2005049021A1 - Materials and methods for inhibiting neointimal hyperplasia

Info

Publication number: WO2005049021A1
Application number: PCT/EP2004/012406
Authority: WO
Inventors: Pekka Juha HÄYRY
Original assignee: Oy Helsinki Transplantation R & D Ltd
Priority date: 2003-11-03
Filing date: 2004-11-03
Publication date: 2005-06-02

Abstract

The present invention is based, in part, on the novel, inventive combination of an inhibitor of a mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R) in treating or preventing neointimal hyperplasia. The effect is synergistic and long lasting. In some embodiments, the mTOR inhibitor comprises rapamycin and the PDGF-R inhibitor comprises imatinib mesylate. As discussed in greater detail herein, the inhibitors may administered in a common mixture or as a separate composition, they may also be administered in any number of different ways including orally, e.g., by pill, or locally, e.g., by means of a stent coating.

Description

MATERIALS AND METHODS FOR INHIBITING NEOINTIMAL HYPERPLASIA This application claims the benefit of U.S. Provisional Application No. 60/517,165, filed November 3, 2003, which is herein incorporated by reference in their entirety. FIELD OF THE INVENTION This invention generally relates to use of materials and methods to inhibit, prevent, or treat vascular fibrointimal hyperplasia and vascular remodeling in such conditions as atherosclerosis, stenosis, and restenosis, in diabetic and autoimmune vascular disorders and after allograft or organ transplantation in the graft or transplant itself and in the transplant recipient locally or systematically. BACKGROUND Cardiovascular disorders are some of the major challenges of modern medicine. Many of these disorders involve neointimal hyperplasia, i.e., pathological growth at the inner layer of a blood vessel (including classical (natural) atherosclerosis as well as disorders often associated with diabetes, organ and tissue transplant complications, and damage associated with catheters, stents and other medical devices). Neointimal hyperplasia (also referred to as vascular fibrointimal hyperplasia, or fibro neointimal hyperplasia) develops as a universal response to vascular injury, regardless of the triggering mechanism (oxidative; mechanical; or immunological). While the composition of the neointima may depend on the nature of the injury, myofibroblastoid cell accumulation and extracellular matrix (ECM) deposition are consistent histological features. Rapamycin (sirolimus), a macrolide immunosuppressant, forms a complex with the intracellular receptor FKBP12. The resulting complex inhibits the kinase known as "mammalian Target of Rapamycin" or mTOR. This inhibition affects cell growth at the Gl checkpoint, causing cells to return to a quiescent state. (See, e.g., Toutouzas, K., et al, Zeitschrift Kardiologie, 91 suppl.3. '49-57 (2002).) Rapamycin is labeled for use in kidney and liver transplantation, has been shown to inhibit neointimal hyperplasia caused by either mechanical (post-PTCA restenosis) or immune (transplant arteriopathy) injury. (See Gregory, et al, Transplantation Proceedings, 25(1):120-121 (1993a); Gregory, et al, Transplantation Proceedings 25(1): 770-771 (1993b); Gregory, et al, Transplantation 55(6):1409-1418 (1993c).) In early rat studies, continuous administration of the drug (1.5 mg/kg/d, i.p.) approximately halved restenosis at day 14, but had no reported impact on transplant arteriopathy at day 40. However, the latter reportedly was completely inhibited by higher doses of the drug. (Gregory 1993a,b,c). Later studies suggested that, at least in the restenosis model, rapamycin lacked long-term efficacy, as continuous treatment for 14 or 30 days following injury (in combination with mycophenolate mofetil (MMF)) did not appreciably reduce neointimal hyperplasia at day 44 (Gregory et al, Transplantation 59(5):655-661 (1995)). Overall, the vasculoprotective properties of rapamycin in animal models are limited by its low (~14%) and variable oral bioavailability (Shaw 2000); its powerful immunosuppressive effects (Gregory CR, et al, Transplantation 2001; 72(6): 989-993); and its toxicity profile (Chan 1995; Walpoth 2001). Furthermore, rapamycin appears not to halt the development of neointimal hyperplasia in synthetic vascular grafts (Walpoth 2001). Some of these limitations have been addressed in the clinic with the development of a rapamycin-coated stent, which has suppressed neointimal hyperplasia for up to 6-12 months in clinical trials (Sousa, Circulation, 104:2007-11 (2001)), although this protective effect may not persist indefinitely (Sousa, Circulation, 107:381-3 (2003)). Complications, including subacute thrombosis, have been reported with such stents. Moreover, stenting is not an optimal treatment for the prevention of classical atherosclerosis, diabetic or autoimmune angiopathy, transplant arteriopathy or accelerated atherosclerosis in the transplant recipient. The prevention of restenosis after obstructive femoral artery disease with rapamycin-coated stents is marginal (Duda, Circulation 2002:106:1505-9), and oral rapamycin with non-coated stents seems not to be sufficient to prevent restenosis (Rodriguez J. Invasive Cardiol. 2003:15:581-4). Problems associated with eluting stents include safety issues such as thrombosis, late malapposition, aneurysm, edge effects, overlapped segments and polymer-induced inflammation. (See, e.g., idolfi, et al, Trends Cardiovasc. Med. 13:142-148 (2003).) Narious adverse reactions have been associated with oral rapamycin use including, but not limited to, hypercholesterolemia, hyperhpemia, hypertension, rash, acne, anemia, arthralgia, diarrhea, hypokalemia, and thrombocytopenia. As an immunosuppressant, use of rapamycin may increase the susceptibility to infection. A need exists for novel therapeutic regimens that exploit the cardiovascular benefits of rapamycin while minimizing the immunosuppressive effects and assorted side effects of rapamycin. Prescott, U.S. Pat. Appl. No. 2003/0170287, describes using rapamycin or rapamycin derivatives for treatment of certain vascular diseases, and suggests optionally combining the rapamycin with a variety of other "active compounds." Prescott fails to demonstrate improved efficacy with a combination of compounds. Imatinib mesylate (CGP57148B; STI-571), a selective inhibitor of the Abl, PDGF-R, and c-kit tyrosine kinases originally labeled as an anti-leukemic agent, has been shown to attenuate neointimal hyperplasia in rat models of restenosis (Myllamiemi M, et al, FASEB J 1997; 11(13): 1119-1126; Myllamiemi M, et al, Cardiovasc Drags Ther 1999; 13(2): 159-168) and rat transplant arteriopathy (Sihvola R, et al, Circulation 1999; 99(17): 2295-2301). Specifically, continuous oral administration of the drug (50 mg/kg/d) reportedly inhibited restenosis by 90% at day 14 (Myllamiemi 1997, 1999); and approximately halved the size of lesions in transplant arteries, when used in combination with a suboptimal does of cyclosporine (Sihvola R, et al, Circulation 1999; 99(17): 2295- 2301). The potential of imatinib as a vasculoprotective agent is enhanced by its favorable toxicity profile (doses as high as 1 g/d are well tolerated in humans) and high oral bioavailability (-98%) (FDA approval summary). Adverse reactions that may be associated with imatinib use include, but are not limited to, edema, nausea, vomiting, diarrhea, and muscle cramps, imatinib seems to act in vasculoprotection primarily at the plasma membrane receptor level, including PDGF receptor inhibition. Inhibition of PDGF molecules has been reported to have limitations in the context of anti-restenosis therapies. (See, e.g., Leppanen, et al, Arterioscler. Thromb. Vase. Biol. 20:89-95 (2000).) Both rapamycin and imatinib mesylate are metabolized largely by the cytochrome oxidase CYP3A4. Both rapamycin and imatinib to date have been reported to be relatively short-term in their ability to prevent or diminish neointimal hyperplasia. As vasculopathies generally represent chronic disorders, a need exists for longer acting therapies. The main reason of organ graft loss is death with graft function (53%), followed by chronic rejection (allograft arteriosclerosis, 36%) (Paul 2001 in EBPG Expert Group 2002). Of all deaths with graft function, 42% are cardiovascular (Ojo et al., Kidney Int., 57:307 (2000)). Fibrointimal hyperplasia is a frequent complication of endovascular surgery, PTCA procedures, and of intravascular stents. The increasing prevalence of peripheral and coronary atherosclerotic heart disease and other arteriopathies, as well as the extensive use of organ transplants, angioplasty and vascular stents in the population, and the absence of optimal therapy showing sustained effect without side effects, highlight the need for new compositions and treatments for vascular neointimal hyperplasia. Stenosis of the vein proximal of the anastomosis site is a frequent complication of the shunt (Sugimoto, et al., Eur. J. Radio. 13:1615-1619 (2003); van der Linden, et al., Am. J. Soc. Nephrol. 13:715-720 (2002)). The standard treatment is percutaneous transluminal angioplasty or PTA. Approximately 50% of successful PTAs result in restenosis within 6 months postoperatively (van der Linden 2002). Accordingly, new therapies are needed for preventing stenosis and restenosis in shunts and fistulas. SUMMARY OF THE INVENTION The present invention provides novel materials and methods for addressing one or more of the problems identified above. For example, mTOR inhibitors and PDGF-R inhibitors are used in combination to treat, prevent, or inhibit various conditions such as arteriosclerosis, including, but not limited to, atherosclerosis, stenosis and restenosis (e.g., in angioplasty or organ/graft contexts). Transplant recipients maybe particularly susceptible to transplant arteriosclerosis (which may be characterized by concentric, non-calcified neointimal growth with immune or traumatic causations as opposed to focal, calcified and eccentric lesions that may be found in non-transplant- associated atherosclerosis) and to accelerated atherosclerosis. However, the compositions and methods of the present invention are applicable to any type of patient diagnosed or predisposed to atherosclerosis in general. Atheroscleosis is a slowly-progressing systemic form of fibroproliferative vascular disease characteristic of plaque and atheroma formation, with coronary, carotid, peripheral and other manifestations. One aspect of this invention is a composition comprising an inhibitor of the kinase known as mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R). Any compounds having mTOR and/or PDGF-R inhibitory activities may be used to make compositions of the invention. Moreover, compositions of the invention may include more than one mTOR inhibitor and/or more than one PDGF-R inhibitor. The composition preferably contains amounts or concentrations of the inhibitors that are effective for inhibiting or preventing neointimal hyperplasia in a mammalian subject. The amounts or concentrations are more effective than either inhibitor alone in the mammalian subject. In some variations, the combinations of agents is therapeutically effective with fewer side-effects than therapeutically effective amounts of either inhibitor administered alone. In some embodiments, the inhibitors are present in amounts or concentrations effective for synergistically inhibiting or preventing neointimal hyperplasia. In some embodiments, the mTOR inhibitor comprises rapamycin. In some embodiments, the PDGF-R inhibitor comprises imatinib mesylate or an equivalent salt thereof. Compositions of the invention optionally further include additional agents. For example, compositions of the invention may include one or more physiologically or pharmaceutically acceptable formulation agents. Compositions of the invention optionally further include additional classes of therapeutic agents to further enhance prophylaxis against atherosclerosis, or to treat other conditions of a subject. For example, in some embodiments, the composition further includes a somatostatin receptor 1,4 selective agonist, or an estrogen receptor beta selective agonist. Another aspect of the invention, related to compositions of the invention, is the use of the components of any composition of the invention for the manufacture of a medicament for treatment or preventions of conditions described herein. Another aspect of this invention is a method of inhibiting neointimal hyperplasia, such as classical atherosclerosis, in a mammalian subject, e.g., humans, comprising administering to a mammalian subject in need of treatment to inhibit or prevent neointimal hyperplasia an inhibitor of mammalian Target of Rapamycin (mTOR) and a platelet derived growth factor receptor (PDGF-R) inhibitor, in amounts effective to inhibit neointimal hyperplasia. In some embodiments, the inhibitors are administered in amounts or concentrations effective for synergistically inhibiting or preventing neointimal hyperplasia. The invention also includes any medical device containing or carrying the inhibitors, such as a stent, catheter, fistula, or shunt. Thus, another aspect of the invention is an endovascular stent designed to contact a surface of a blood vessel to treat stenosis of the blood vessel, the stent comprising a surface for contacting a surface of a blood vessel, and a composition on said surface, said composition comprising an inhibitor of mammalian target of rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R), wherein the inhibitors are included in the composition in amounts effective to inhibit neointimal hyperplasia in a blood vessel or other body lumen. In some embodiments, the inhibitors are present in amounts or concentrations effective for synergistically inhibiting or preventing neointimal hyperplasia. In some embodiments, the mTOR inhibitor comprises rapamycin. In some embodiments, the PDGF-R inhibitor comprises imatinib mesylate. In the aforementioned embodiments, the "composition" should be understood to embrace embodiments wherein the two or more inhibitors are separately applied to the stent in distinct formulations. Still another aspect of the invention is an extravascular collar designed to contact a surface of a blood vessel in the course of surgery to treat stenosis of the blood vessel, the collar comprising an outer wall shaped to surround the outer surface of a blood vessel, wherein the wall encloses a space containing an inhibitor of mammalian target of rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R), wherein the inhibitors are provided in amounts effective to inhibit neointimal hyperplasia in a blood vessel or other lumen, hi some embodiments, the inhibitors are present in amounts or concentrations effective for synergistically inhibiting or preventing neointimal hyperplasia. In some embodiments, the mTOR inhibitor comprises rapamycin. In some embodiments, the PDGF-R inhibitor comprises imatinib mesylate. hi the aforementioned embodiments, the "composition" should be understood to embrace embodiments wherein the two or more inhibitors are separately applied to the collar in distinct formulations. Another aspect of the invention is a catheter having a surface for contacting a surface of a blood vessel, and a composition on said surface, said composition comprising an inhibitor of mammalian target of rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R), wherein the inhibitors are provided on the surface in amounts effective to inhibit neointimal hyperplasia in a blood vessel or other body lumen, i some embodiments, the inhibitors are present in amounts or concentrations effective for synergistically inhibiting or preventing neointimal hyperplasia. some embodiments, the mTOR inhibitor comprises rapamycin. In some embodiments, the PDGF-R inhibitor comprises imatinib mesylate. In the aforementioned embodiments, the "composition" should be understood to embrace embodiments wherein the two or more inhibitors are separately applied to the catheter in distinct formulations. Another aspect of the invention is a balloon catheter having a void for holding a therapeutic agent for delivery to the interior of a blood vessel, and a composition contained in the void, the composition comprising an inhibitor of mammalian target of rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R), wherein the inhibitors are provided in the void in amounts effective to inhibit neointimal hyperplasia. In some embodiments, the inhibitors are present in amounts or concentrations effective for synergistically inhibiting or preventing neointimal hyperplasia. hi some embodiments, the mTOR inhibitor comprises rapamycin. In some embodiments, the PDGF-R inhibitor comprises imatinib mesylate. In the aforementioned embodiments, the "composition" should be understood to embrace embodiments wherein the two or more inhibitors are separately applied to the catheter void in distinct formulations. Still another aspect of the invention is a unit dose comprising an inhibitor of mammalian target of rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R), wherein the inhibitors are provided in amounts effective to inhibit neointimal hyperplasia when co-administered; wherein the inhibitors are packaged together for co-administration to a human subject, but are not in admixture. In some embodiments, the inhibitors are present in amounts or concentrations effective for synergistically inhibiting or preventing neointimal hyperplasia. In some embodiments, the mTOR inhibitor comprises rapamycin. hi some embodiments, the PDGF-R inhibitor comprises imatinib mesylate. Another aspect of the invention is the treatment using the compositions of the present invention to treat atherosclerosis, transplant arteriosclerosis, accelerated atherosclerosis, retinopathies, chronic rejection, stenoses, restenoses, diabetic and autoimmune angiopathies, as well as without limitation other fibroproliferative vasculopathies, and other disorders discussed herein. For materials and methods of this invention, references to PDGF-R inhibitors include metabolites, esters, prodrugs, salts, and hydrates of the same that have, or are modified to have in vivo, PDGF-R inhibitor activity. Similarly, references to mTOR inhibitors or methods of using the same include without limitation metabolites, esters, prodrugs, salts, and hydrates of the same that have, or are modified to have in vivo, PDGF-R inhibitor activity. Transplants include autografts, allografts, and xenografts. hi a related variation, the invention includes use of an mTOR inhibitor and a PDGF-R inhibitor in combination for the manufacture of a medicament for treatment, prevention, or inhibition of any of the diseases, disorders, or conditions described herein (e.g., in the context of methods of treatment), hi preferred embodiments, synergistically effective amounts of the inhibitors are employed. This summary of the invention is not intended to be limiting or comprehensive, and additional embodiments are described in the drawings and detailed description, including the examples. All such embodiments are aspects of the invention. Moreover, for the sake of brevity, various details that are applicable to multiple embodiments have not been repeated for every embodiment. Variations reflecting combinations and rearrangements of the embodiments described herein are intended as aspects of the invention. In addition to the foregoing, the invention includes, as an additional aspect, all embodiments of the invention narrower in scope in any way than the variations specifically mentioned above. For example, for aspects described as a genus or range, such as dosages or dosing regimens, every subgenus, subrange or species is specifically contemplated as an embodiment of the invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a cross-section of a blood vessel into which a drug delivery balloon catheter including a protective sheath has been inserted, the protective sheath serving to cover the balloon during insertion and positioning. FIG. 2A depicts a perspective view of an expandable membrane having two layers that are spaced apart, prior to joining edges of the layers to each other. FIG. 2B depicts a perspective view of the membrane of FIG. 2 A that has been rolled into a tube and had opposite edges adjoined. FIGS 3 A and 3B depict, in perspective (3 A) and longitudinal cross-section (3B), schematic views of an extravascular collar surrounding a portion of a blood vessel. FIG. 4A depicts in cross-section a wire coated with a polymer or gel that can include (e.g., be impregnated with) a therapeutic composition. FIG. 4B depicts a perspective view of an intravascular stent formed from the wire of FIG. 4A. FIG. 5 is a graph showing the dose-dependent inhibition of neointimal hyperplasia by rapamycin with an endpoint of 14 days. FIG. 6 is a graph showing the dose-dependent inhibition of neointimal hyperplasia by imatinib mesylate (STI-571) with an endpoint of 14 days. FIG. 7 is a graph showing the mean initimal nuclei count with an endpoint of 14 days of control (rat) subjects, subjects receiving rapamycin or imatinib mesylate, or both drugs. FIG. 8 is a graph showing the mean initimal nuclei count with an endpoint of 40 days of control (rat) subjects, subjects receiving rapamycin or imatinib mesylate, or both drugs. FIG. 9 A shows the percentage of wells showing cell outgrowth (migration) at day 1 and 2 of ex vivo growth of tissue samples (aortic explants) derived from PTCA- injured rats on the various drug regimens (saline/control; lOmg/kg/d imatinib meslyate, 1 mg/kg/d of sirolimus, both drugs in combination; stars indicate p values compared to controls). FIG. 9B shows the millimeter (mm) distance of cell migration from tissue samples derived from PTCA-injured rats on the various drug regimens. FIG. 9C shows the proliferation of migrated cells after 3H-thymidine labeling distance of cell migration from tissue samples derived from PTCA-injured rats on the various drug regimens. FIG. 10A is a representative microphotograph of a left carotid artery tissue sample from a baboon sacrificed 3 days after PTC A of the left carotid and iliac arteries showing BrDU-incorporated cells with Mayer's counterstaining at an objective magnification of 100X (arrows indicate stained cells). FIG. 10B shows the number of BrdU-labeled cells in a left carotid artery tissue sample from baboons sacrificed at various time points after PTC A of the left carotid and iliac arteries. FIG. 10C is a representative microphotograph of a right carotid artery tissue sample from a baboon sacrificed 3 days after PTC A of the left carotid and iliac arteries showing BrDU-incorporated cells with Mayer's counterstaining at an objective magnification of 100X (arrows indicate stained cells). FIG. 10D shows the number of BrdU-labeled cells in a right carotid artery tissue sample from baboons sacrificed at various time points after PTC A of the left carotid and iliac arteries. FIG. 10E is a representative microphotograph of a left iliac artery tissue sample from a baboon sacrificed 3 days after PTC A of the left carotid and iliac arteries showing BrDU-incorporated cells with Mayer's counterstaining at an objective magnification of 100X (arrows indicate stained cells). FIG. 10F shows the number of BrdU-labeled cells in a left iliac artery tissue sample from baboons sacrificed at various time points after PTC A of the left carotid and iliac arteries. FIG. 10G is a representative microphotograph of a right iliac artery tissue sample from a baboon sacrificed 3 days after PTC A of the left carotid and iliac arteries showing BrDU-incorporated cells with Mayer's counterstaining at an objective magnification of 100X (arrows indicate stained cells). FIG. 10H shows the number of BrdU-labeled cells in a right iliac artery tissue sample from baboons sacrificed at various time points after PTC A of the left carotid and iliac arteries. FIG. 11 A shows the frequency of replicating cells by number of cells per unit area (0.0625 mm²) stained for using Ki67 antigen, PCNA antigen and incorporation of BrdU in the abdominal aorta (allograft) in baboons sacrificed at various time points following transplantation. Cells of the intima, media, and adventitia layers were studied. FIG. 1 IB shows the frequency of replicating cells by number of cells per unit area (0.0625 mm²) stained for using Ki67 antigen, PCNA antigen and incorporation of BrdU in the thoractic aorta in baboons sacrificed at various time points following transplantation. Cells of the intima, media, and adventitia layers were studied. FIG. 11C shows the frequency of replicating cells by number of cells per unit area (0.0625 mm²) stained for using Ki67 antigen, PCNA antigen and incorporation of BrdU in a segment of the left carotid artery in baboons sacrificed at various time points following transplantation. Cells of the intima, media, and adventitia layers were studied. FIG. 1 ID shows the frequency of replicating cells by number of cells per unit area (0.0625 mm²) stained for using Ki67 antigen, PCNA antigen and incorporation of BrdU in a segment of the right carotid artery in baboons sacrificed at various time points following transplantation. Cells of the intima, media, and adventitia layers were studied. FIG. 1 IE shows the frequency of replicating cells by number of cells per unit area (0.0625 mm²) stained for using Ki67 antigen, PCNA antigen and incorporation of BrdU in a segment of the left iliac artery in baboons sacrificed at various time points following transplantation. Cells of the intima, media, and adventitia layers were studied. FIG. 1 IF shows the frequency of replicating cells by number of cells per unit area (0.0625 mm²) stained for using Ki67 antigen, PCNA antigen and incorporation of BrdU in a segment of the right iliac artery in baboons sacrificed at various time points following transplantation. Cells of the intima, media, and adventitia layers were studied. FIG. 11G shows the frequency of replicating cells by number of cells per unit area (0.0625 mm²) stained for using Ki67 antigen, PCNA antigen and incorporation of BrdU in a segment of the left coronary artery in baboons sacrificed at various time points following transplantation. Cells of the intima, media, and adventitia layers were studied. FIG. 1 IH shows the frequency of replicating cells by number of cells per unit area (0.0625 mm²) stained for using Ki67 antigen, PCNA antigen and incorporation of BrdU in a segment of the right coronary artery in baboons sacrificed at various time points following transplantation. Cells of the intima, media, and adventitia layers were studied. While the disclosure is susceptible to various modifications and alternative constructions, certain illustrative embodiments thereof have been shown in the drawings and will be described herein in detail. It should be understood, however, that there is no intention to limit the invention to the specific forms disclosed, but on the contrary, the intention is to cover all modifications, alternative constructions, and the equivalents falling within the spirit and scope of the disclosure as defined by the appended claims. DETAILED DESCRIPTION The present invention is based, in part, on the discovery that administration of an mTOR inhibitor and a PDGF-R inhibitor are especially effective for preventing neointimal hyperplasia, and at lower than expected concentrations, hi some embodiments, the mTOR inhibitor comprises rapamycin (sirolimus; e.g., Rapamune, Wyeth- Ayerst) and the PDGF-R inhibitor comprises imatinib mesylate (e.g., Gleevec (Glivec), Novartis). As discussed in greater detail herein, the inhibitors may be administered in a common mixture (composition) or as separate compositions, they may also be administered in any number of different ways including orally, e.g., by pill, or locally, e.g., by means of a stent coating. Inhibitors may comprise, but are not limited to, those compounds that block, in part or completely, such processes as ligand-receptor binding as well as enzymatic, e.g., kinase, activity. PDGF-R inhibitors include, but are not limited to, inhibitors of PDGF-R-α homodimers, PDGF-R-β homodimers, and PDGF-R-αβ heterodimers. Inhibitors also comprise molecules that target the ligands of mTOR and PDGF-R receptors. PDGF targets may comprise homodimers or heterodimers or combinations thereof of PDGF- A, PDGF-B, PDGF-C and PDGF-D. (E.g., Platelet-derived growth factor A (PDGF-A) (see e.g., GenBank Ace. No. X06374). Platelet-derived growth factor B (PDGF-B) (see e.g., GenBank Ace. No. M12783) Platelet-derived growth factor C (PDGF-C) (see e.g., GenBank Ace. No. AAF80597). Platelet-derived growth factor D (PDGF-D) (see e.g., GenBank Ace. No. AAK56136). PDGF inhibitors may include, but are not limited to those of Clader, et al, U.S. Pat. No.: 5,238,950, Ross et al, U.S. Pat. No.: 5,648,076; Brown, et al, U.S. Pat No. 5,795,898; Pershadsingh, et al, U.S. Pat. No. 5,866,595, all incorporated by reference for their teachings of inhibitors and how to make and use them. Inhibitors that may be used in accordance with the present invention include, but are not limited to, competitive, non-competitive, reversible, irreversible, and mixed inhibitors or combinations thereof, hibitors may also be antagonists of the particular kinases. SYNERGISM Pharmaceutical (medicinal) treatment options have been suggested for many of the conditions described herein, which offer varying degrees of relief in reported trials, depending on the subject and the condition treated. Here, mTOR inhibitors and PDGF-R inhibitors are used in materials or methods together to improve efficacy compared to either compound alone, preferably so as to achieve a synergistic effect as judged by one or more of a number of criteria. This synergism may, for example, manifest itself in lower effective doses of one or both inhibitors, which will reduce costs and/or reduce adverse side-effects and toxicity. The inhibition or prevention of neointimal neoplasia for a longer duration also represents synergism. For example, in some embodiments, the combination therapy may be administered for a given time period and then suspended; neointimal hyperplasia may be suppressed even after suspension for a greater duration than if only a single compound were employed. In some embodiments, a greater therapeutic window (range between lowest effective dose and toxic dose) is contemplated. In some embodiments, equivalent or better (e.g, synergistic) inhibition is achieved compared to the use of any one compound alone, and with fewer side effects than when a single compound is employed. Alternatively, amounts of each inhibitor are considered synergistic by satisfying the following formula: D(mTORinhibitor) D(PDGF - Rinhibitor) EeD(mTORinhibitor) EeD(PDGF - Rinhibitor) wherein D(mTOR inhibitor) is the dose of mTOR inhibitor administered and D(PDGF-R inhibitor) is the dose of PDGF-R inhibitor administered to achieve a particular degree of inhibition or prevention of neointimal hyperplasia; wherein EeD(mTOR inhibitor) is an equi-effective dose of mTOR inhibitor and EeD(PDGF-R inhibitor) is an equi-effective dose of PDGF-R inhibitor; wherein the equi-effective dose of mTOR inhibitor and the equi-effective dose of PDGF-R inhibitor result in the same quantity of inhibition or prevention of neointimal hyperplasia. See e.g., Berenbaum, "Synergy, Additivism, and Antagonism in hnmunosuppression," Clin. Exp. Immunol. 28:1-18 (1977); Berenbaum, J. Antimicrob. Chemother. 19(2):271-273 (1987); which are incorporated herein in its entirety Such quantity may manifest itself, for example, as fewer total neointimal nuclei, thinner neointimal deposits, or longer periods of neointimal hyperplasia suppression. hi subjects that require cardiovascular therapy described herein, but do not require immunosuppressive therapy, the toxicity of mTOR inhibitors, e.g. rapamycin and its derivatives, due to immunosuppressant and other effects is undesirable, and use of a PDGF-R inhibitor to achieve therapeutic efficacy with lower dosages of mTOR inhibitors is specifically contemplated. Thus, in accordance with some embodiments, a low dose of an mTOR inhibitor, e.g., rapamycin, is paired with a medium dose of imatinib to inhibit neointimal hyperplasia with reduced side (e.g., immunosuppressive) effects compared to treatment of neointimal hyperplasia with mTOR inhibitor alone. COMPOUNDS Exemplary inhibitors of mTOR and PDGF-R include, but are not limited to, the following drags, the formulation of which is known in the art and/or published in patent and trade literature, which is incorporated herein in its entirety. The inhibitors may include without limitation small molecules, polynucleotides, polypeptides, antibodies, metals, aptamers, antisense and interference RNA, chelators, etc. Exemplary inhibitory compounds and compositions are discussed herein. The pharmaceuticals (e.g., medicines, drugs, biologically active compounds, etc.) that may be used according to this disclosure include, but are not limited to, biologically active compounds (hereinafter, "compounds") such as mTOR inhibitors and PDGF-R inhibitors, h some embodiments, the pharmaceuticals include rapamycin as a mTOR inhibitor and imatinib mesylate as a PDGF-R inhibitor.

A. SMALL MOLECULES mTOR inhibitors include, but are not limited to the following drugs:

In addition to rapamycin and those derivatives of rapamycin listed in the above table those discussed in U.S. Pat. Appl. No. 20030170287 may also be used. See also WO 94/09010, and WO 96/41807. Rapamycin derivatives may also include without limitation "rapalogs," e.g., as disclosed in WO 98/02441 and WO01/14387; deuterated rapamycin analogs, e.g., as disclosed in U.S. Pat. 6,503,921. Derivatives of other mTOR inhibitors are also contemplated. Rapamycin derivative having mTOR inhibiting properties is meant a substituted rapamycin, e.g., a 40-substituted-rapamycin or a 16-substituted rapamycin, or a 32-hydrogenated rapamycin, for example a compound of formula A:

wherein Ri is CH₃ or C₃-6alkynyl, R₂ is H, ~CH₂-CH₂-OH, 3-hydroxy-2-(hydroxymethyl)- -2-methyl- propanoyl or tetrazolyl, and X is =O, (H,H) or (H,OH) provided that R₂ is other than H when X is =O and R_\ is CH₃, or a prodrug thereof when R₂ is -CH₂-CH₂-OH, e.g. a physiologically hydrolysable ether thereof. Rapamycin derivatives of formula A include without limitation 32- deoxorapamycin, 16-pent-2-ynyloxy-32-deoxorapamycin, 16-pent-2-ynyloxy-32(S or R)- dihydro-rapamycin, 16-pent-2-ynyloxy-32(S or R)-dihydro-40-O-(2-hydroxyethyl)- rapamycin, 40-[3-hydroxy-2-(hydroxymethy- l)-2-methylpropanoate]-rapamycin (also called CC1779) or 40-epi-(tetrazolyl)-rapamycin (also called ABT578). 40-O-(2- hydroxyethyl)-rapamycin disclosed in Example 8 in WO 94/09010. 32-deoxorapamycin and 16-pent-2-ynyloxy-32(S)-dihydro-rapamycin as disclosed in WO 96/41807. Exemplary Platelet-Derived Growth Factor Receptor (PDGF-R) inhibitors include the following without limitation:

The above list of PDGF-R inhibitors is not meant to be limiting. Any PDGF-R inhibitor may be employed, including without limitation PDGF-R inhibitors described in U.S. Pat. Nos. 5,932,580, 6,331,555, and 6,358,954; WO 99/28304; WO 00/09098; WO 01/64200. Other inhibitors that may be used include 3-Substituted frιdolin-2-ones (e.g., SU5416, SU6668), and derivatives thereof (Sun et al., J. Med. Chem., 41:2588-2603; Sun et al., J. Med. Chem. 43:2655-2663 (2000)); 2-Amino-8H- pyrido[2,3-d]pyrimidines (Boschelli et al., J. Med. Chem. 41:4365-4377 (1998)). In some embodiments, the PDGF-R inhibitor is a compound described in U.S. Patent No. 5,521,184 with a stracture according to the following formula B:

According to a first aspect, the N-phenyl-2-pyrimidine-amine compound of formula B is a compound wherein R\ is 4-pyrazinyl, 1 -methyl- lH-pyrrolyl, amino- or amino-lower alkyl-substituted phenyi wherein the amino group in each case is free, alkylated or acylated, lH-indolyl or lH-imidazolyl bonded at a five-membered ring carbon atom, or unsubstituted or lower alkyl-substituted pyridyl bonded at a ring carbon atom and unsubstituted or substituted at the nitrogen atom by oxygen; wherein R₂ and R₃ are each independently of the other hydrogen or lower alkyl, one or two of the radicals ₄, R₅, R₆, R₇ and R₈ are each nitro, fluoro-substituted lower alkoxy or a radical of formula C -N(R₉)-C(-X)-(Y)_n -R₁₀ (C) wherein R₉ is hydrogen or lower alkyl, X is oxo, thio, imino, N-lower alkyl-imino, hydroximino or O-lower alkyl-hydroximino, Y is oxygen or the group NH, n is 0 or 1 and R₁₀ is an aliphatic radical having at least 5 carbon atoms, or an aromatic, aromatic-aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, heterocyclic or hetero- cyclicaliphatic radical, and the remaining radicals R₄, R₅, Rj, R₇ and R₈ are each independently of the others hydrogen, lower alkyl that is unsubstituted or substituted by free or alkylated amino, piperazinyl, piperidinyl, pyrrolidinyl or by morpholinyl, or lower alkanoyl, trifluoromethyl, free, etherified or esterifed hydroxy, free, alkylated or acylated amino or free or esterified carboxy, or a salt of such a compound having at least one salt- forming group. hi some embodiments, the compound of formula B is defined by the first aspect and further characterized wherein one or two of the radicals i, R₅, R₆, R₇, and R₈ are each nitro or a radical of formula C; wherein R₉ is hydrogen or lower alkyl, X is oxo, thio, imino, N-lower alkyl-imino, hydroximino or O-lower alkyl-hydroximino, Y is oxygen or the group NH, n is 0 or 1 and R₁₀ is an aliphatic radical having at least 5 carbon atoms or an aromatic, aromatic-aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, heterocyclic or hetero-cyclicaliphatic radical, and the remaining radicals R₄, R₅, R₆, R₇, and R₈, are each independently of the others hydrogen, lower alkyl that is unsubstituted or substituted by free or alkylated amino, piperazinyl, piperidinyl, pyrrolidinyl or by morpholinyl, or lower alkanoyl, trifluoromethyl, free, etherified or esterifed hydroxy, free, alkylated or acylated amino or free or esterified carboxy, or a salt of such a compound having at least one salt-forming group. In some embodiments, the compound of formula B is defined by the first aspect and further characterized wherein Ri is 4-pyrazinyl, 1 -methyl- lH-pyrrolyl, amino- or amino-lower alkyl-substituted phenyi wherein the amino group in each case is free, alkylated by one or two lower alkyl radicals or acylated by lower alkanoyl or by benzoyl, lH-indolyl or lH-imidazolyl bonded at a five-membered ring carbon atom, or unsubstituted or lower alkyl-substituted pyridyl bonded at a ring carbon atom and unsubstituted or substituted at the nitrogen atom by oxygen, R₂ and R₃ are each independently of the other hydrogen or lower alkyl, one or two of the radicals Rt, R₅, R , R₇ and R₈ are each nitro, fluoro-substituted lower alkoxy or a radical of formula II wherein R is hydrogen or lower alkyl, X is oxo, thio, imino, N-lower alkyl-imino, hydroximino or O-lower alkyl-hydroximino, Y is oxygen or the group NH, n is 0 or 1 and R₁₀ is an aliphatic hydrocarbon radical having 5-22 carbon atoms, a phenyi or naphthyl radical each of which is unsubstituted or substituted by cyano, lower alkyl, hydroxy-lower alkyl, amino-lower alkyl, (4-methyl-piperazinyl)-lower alkyl, trifluoromethyl, hydroxy, lower alkoxy, lower alkanoyloxy, halogen, amino, lower alkylamino, di-lower alkylamino, lower alkanoylamino, benzoylamino, carboxy or by lower alkoxycarbonyl, or phenyl-lower alkyl wherein the phenyi radical is unsubstituted or substituted as indicated above, a cycloalkyl or cycloalkenyl radical having up to 30 carbon atoms, cycloalkyl- lower alkyl or cycloalkenyl-lower alkyl each having up to 30 carbon atoms in the cycloalkyl or cycloalkenyl moiety, a monocyclic radical having 5 or 6 ring members and 1-3 ring hetero atoms selected from nitrogen, oxygen and sulfur, to which radical one or two benzene radicals may be fused, or lower alkyl substituted by such a monocyclic radical, and the remaining radicals R₄, R₅, Re, R₇, and R₈ are each independently of the others hydrogen, lower alkyl that is unsubstituted or substituted by amino, lower alkylamino, di-lower alkylamino, piperazinyl, piperidinyl, pyrrolidinyl or by morpholinyl, or lower alkanoyl, trifluoromethyl, hydroxy, lower alkoxy, lower alkanoyloxy, halogen, amino, lower alkylamino, di-lower alkylamino, lower alkanoylamino, benzoylamino, carboxy or lower alkoxycarbonyl, or a salt of such a compound having at least one salt- forming group. In some embodiments, the compound of formula B is defined by the first aspect and further characterized wherein R\ is pyridyl bonded at a ring carbon atom and unsubstituted or substituted at the nitrogen atom by oxygen, R₂ and R₃ are each hydrogen, i is hydrogen or lower alkyl, R₅ is hydrogen, lower alkyl or fluoro-substituted lower alkoxy, Re is hydrogen, R₇ is nitro, fluoro-substituted lower alkoxy or a radical of formula II wherein R₉ is hydrogen, X is oxo, n is 0 and R₁₀ is an aliphatic hydrocarbon radical having 5-22 carbon atoms, a phenyi radical that is unsubstituted or substituted by cyano, lower alkyl, (4-methyl-piperazinyl)-lower alkyl, lower alkoxy, halogen or by carboxy; a cycloalkyl radical having up to 30 carbon atoms or a monocyclic radical having 5 or 6 ring members and 1-3 sulfur ring atoms, and R₈ is hydrogen, or a pharmaceutically acceptable salt of such a compound having at least one salt-forming group. In some embodiments, the compound of formula B is defined by the first aspect and further characterized wherein R\ is pyridyl or N-oxido-pyridyl each of which is bonded at a carbon atom, R₂ and R are each hydrogen,

is hydrogen or lower alkyl, R₅ is hydrogen, lower alkyl or trifluoromethyl, Re is hydrogen, R₇ is nitro, fluoro- substituted lower alkoxy or a radical of formula II wherein R₉ is hydrogen, X is oxo, n is the number 0 and R₁₀ is pyridyl bonded at a carbon atom, phenyi that is unsubstituted or substituted by halogen, cyano, lower alkoxy, carboxy, lower alkyl or by 4-methyl- piperazinylmethyl, or C₅-C₇ alkyl, thienyl, 2-naphthyl or cyclohexyl, and R₈ is hydrogen, or a pharmaceutically acceptable salt of such a compound having at least one salt-forming group. h some embodiments, the compound of formula B is defined by the first aspect and further characterized wherein Ri is pyridyl bonded at a carbon atom, R₂, R₃, Ri, R₅, R₆ and R₈ are each hydrogen and R₇ is nitro or a radical of formula C wherein R₉ is hydrogen, X is oxo, n is the number 0 and R₁₀ is pyridyl bonded at a carbon atom, phenyi that is unsubstituted or substituted by fluorine, chlorine, cyano, lower alkoxy, carboxy, lower alkyl or by 4-methyl-piperazinyl-methyl, or C₅-C₇ alkyl, thienyl or cyclohexyl, or a pharmaceutically acceptable salt thereof. hi a highly preferred embodiment, the PDGF-R inhibitor has the following structure in accordance with formula B above:

said compound being N-{5-[4-(4-Methyl-piperazino-methyl)- benzoylamido]-2-methyl-phenyl}-4-(3-p yridyl)-2-pyrimidme-amine or a pharmaceutically acceptable salt thereof. In addition to or in substitution for PDGF-R inhibitors, inhibitors of other tyrosine kinases (receptors and other types as well) may also be used in accordance with this invention. Some of these inhibitors may inhibit multiple kinases including, but not limited to, PDGF-Rs. Appropriate TK inhibitors are also taught in WO 99/03854; WO 01/64200; US 5,521,184; WO 00/42042; WO 00/09098; EP 0 564409 Bl; US 5,521,184; WO 97/32604; US 6,610,688; US Patent Appl. Pub. No. 20030194749; Livitzki, A., et al, "Protein Tyrosine Kinase Inhibitors as Novel Therapeutic Agents, " Pharmacol. Ther. 82:231-29 (1999). Other classes of compounds may also be employed. For example and without limitation, Leflunomide (U.S. 4284786) and/or derivative FK778 may be used. (See, e.g., Savikko Transplantation 2003:76:455 and editorial Williams ibid p 471.) According to another aspect of the invention, an estrogen receptor-beta agonist and/or somatostatin receptor 1,4 selective agonist is combined with the mTOR/PDGF-R inhibitor combination therapy. Somatostatin receptor (SSTR) active agonists include without limitation somatostatin (SRIF-14), somatostatin (SRIF-28), DADI-SST14, lanreotide (US 4853371), and octreotide (US 4,395,403). (See WO 99/49884; Aavik et al., FASEB J, 16:724-726 (2002)). Other SSTR agonists that maybe used in combination are described in Rohrer et al, Science 282:737-740 (1998), e.g., SS- 14, L-363,377, L-797,591, L-779,976, L-795,778, L-803,087 L-817,818. Estrogen receptor-beta agonists include without limitation those described in Makela et al., Proc Natl Acad Sci U S A. 96(12):7077-82 (1999). WO 00/01716, e.g., 17beta-estradiol and genistein. The patents, patent application publications and other publications (e.g., Journal articles) referenced herein are incorporated in their entirety. B. BIOLOGICAL INHIBITORS Antibodies as well as other "anti" technologies (e.g., aptamers, antisense, interference RNA, etc.) may also be used to inhibit mTOR, PDGF-R, and/or their ligands or other associated molecules. In view of the intracellular location of mTOR, mTOR inhibitors other than anti-mTOR antibodies may be favored in some embodiments. PDGF-R molecules appropriate as antigens may include, without limitation, PDGFR-α [■see e.g., GenBank Ace. No. NM006206], PDGFR-β [see e.g., GenBank Ace. No. NM002609]), and fragments thereof. Monoclonal antibodies may be prepared by recovering spleen cells from immunized animals and immortalizing the cells in a conventional fashion, e.g. by fusion with myeloma cells. The clones are then screened for those expressing the desired antibody. Antibodies for administration to humans, when prepared in a laboratory animal such as a mouse, maybe "humanized", or chimeric, i.e., made to be compatible with the human immune system such that a human subject will not develop an immune response to the antibody. Human antibodies prepared using known methods such as those described for example, in Lonberg, et al, Nature Genetics, 7:13-21 (1994) maybe used for therapeutic administration to subjects. Human mTOR-neutralizing or PDGF-R-Neutralizing antibodies may be generated by phage display techniques such as those described in Aujame, et al, Human Antibodies, 8(4):155-168 (1997); Hoogenboom, TD3TECH, 15:62-70 (1997); and Rader, et al, Curr. Opin. Biotechnol., 8:503-508 (1997), all of which are incorporated by reference. Alternatively, the antibodies are generated in transgenic mice essentially as described in Braggemann and Neuberger, Immunol. Today, 17(8):391-97 (1996) and Bruggemann and Taussig, Curr. Opin. Biotechnol, 8:455-58 (1997). Other applicable inhibitors include, without limitation, antibody fragments, domain antibodies, and polypeptides comprising antibody fragments. Bispecific antibodies that specifically bind to multiple antigens of interest may be produced, isolated, and tested using standard procedures that have been described in the literature. See, e.g., Pluckthun & Pack, Immunotechnology, 3:83-105 (1997). Anti-mTOR and anti-PDGF-R aptamers may be utilized in accordance with the present invention, see generally, Gold, et al, J. Biotechnol. 74:5-13 (2000). Another class of mTOR or PDGF-R inhibitors useful in the present invention is isolated antisense nucleic acid molecules that can hybridize to, or are complementary to, the nucleic acid molecule comprising the mTOR or PDGF-R nucleotide sequence, or fragments, analogs or derivatives thereof. Use of RNA Interference to inactivate or modulate mTOR or PDGF-R expression is also contemplated by this invention. RNA interference is described in U.S. Patent Appl. No. 2002-0162126, and Harmon, G., J. Nature, 11:418:244-51 (2002). C. POLYNUCLEOTIDE-BASED AND POLYPEPTIDE-BASED THERAPIES In another aspect of the invention, the therapeutic effects of mTOR or PDGF-R inhibition is achieved by administration of polynucleotides (including gene therapy vectors comprising such polynucleotides encoding a polypeptide inhibitor) to a subject, hi some embodiments, the PDGF-R inhibitor comprises a soluble extracellular domain fragment of a PDGF-R. In some embodiments, the polypeptides encoded by such polynucleotides may be administered. COMPOSITIONS In yet another aspect, the invention includes compositions of matter that are useful for inhibiting neointimal hyperplasia in human subjects, particularly human subjects having the conditions discussed herein. For example, the invention includes a composition comprising a first compound and a second compound, wherein the first compound is a mTOR inhibitor, e.g., rapamycin or derivative thereof, and the second compound is a PDGF-R inhibitor, e.g., imatinib mesylate, or a derivative, pharmaceutically acceptable salt, hydrate, or prodrug thereof. In some variations, the composition further comprises a pharmaceutically acceptable diluent, adjuvant, excipient, or carrier, to facilitate and improve administration to a human subject. Pharmaceutical formulation chemistry is a well developed art, and exemplary formulation materials and methods are discussed above. Moreover, most approved medications in the categories set forth herein have already been formulated effectively for administration to humans. In some embodiments, it is contemplated that such formulations be minimally modified to include the composition in a stable manner. The first and second compounds, e.g., mTOR inhibitor and PDGF-R inhibitor, preferably are included in the composition or compositions in amounts effective to improve the efficacy of each other, using parameters for evaluation described herein, when administered to a mammalian subject. Compositions comprising an inhibitor of mTOR, an inhibitor of a PDGF- R, or both, may further comprise one or more additional agents to treat or prevent neointimal hyperplasia. Such agents include, but are not limited to, taxol derivatives (e.g., taxane, paclitaxel), batimistat, dexamethosone, actinomycin D, Resten NG, and ABT-578. Non-pharmacological methods may be employed including, without limitation, exercise. Such agents and regimens are discussed in the literature. (See, e.g., Indolfi, et al, "Molecular Mechanisms of I -Stent Restenosis and Approach to Therapy with Eluting Stents, Trends Cardiovasc. Med. 13:142-148 (2003).) The compounds of this invention may also be co-administered with one or more other compounds including without limitation anticoagulants, antineoplastics, antithrombotics, immunosuppressants, thrombolytics, and vasoprotectants. (See, e.g, The Merck Index; Whitehouse Station, NJ; which is incorporated herein in is entirety.) KITS AND UNIT DOSES In related variations of the preceding embodiments, the first compound (e.g., a mTOR inhibitor) may be packaged or formulated together with the second compound (e.g., a PDGF-R inhibitors), e.g., in a kit or package or unit dose, to permit co- administration, but these two compounds are not in admixture. In some embodiments, the two components (compounds) to the kit/unit dose are packaged with instructions for administering the two compounds to a human subject for treatment of one of the above- indicated disorders and diseases. FORMULATIONS Biologically active compounds can be used directly to practice materials and methods of the invention, but in preferred embodiments, the compounds are formulated with pharmaceutically acceptable diluents, adjuvants, excipients, or carriers. The phrase "pharmaceutically or pharmacologically acceptable" refer to molecular entities and compositions that do not produce adverse, allergic, or other untoward reactions when administered to an animal or a human, e.g., orally, topically, transdermally, parenterally, by inhalation spray, vaginally, rectally, by eye drop, or by intracranial injection. (The term parenteral as used herein includes subcutaneous injections, intravenous, intramuscular, intracisternal injection, or infusion techniques. Administration by intravenous, intradermal, intramuscular, intramammary, intraperitoneal, intrathecal, retrobulbar, intrapulmonary injection and/or surgical implantation at a particular site is contemplated as well.) Generally, this will also entail preparing compositions that are essentially free of pyrogens, as well as other impurities that could be harmful to humans or animals. The term "pharmaceutically acceptable carrier" includes any and all solvents, dispersion media, coatings, antibacterial and antifungal agents, isotonic and absorption delaying agents and the like. The use of such media and agents for pharmaceutically active substances is well known in the art. The compounds (e.g., mTOR inhibitor and PDGF-R inhibitor) may include pharmaceutically acceptable salts, particularly where a basic or acidic group is present in a compound. For example, when an acidic substituent, such as -COOH, is present, the ammonium, sodium, potassium, calcium and the like salts, are contemplated as possible embodiments for administration to a biological host. When a basic group (such as amino or a basic heteroaryl radical, such as pyridyl) is present, then an acidic salt, such as hydrochloride, hydrobromide, acetate, maleate, palmoate, phosphate, methanesulfonate, p-toluenesulfonate, and the like, is contemplated as a possible form for administration to a biological host. Similarly, where an acid group is present, then pharmaceutically acceptable esters of the compound (e.g., methyl, tert-butyl, pivaloyloxymethyl, succinyl, and the like) are contemplated as possible forms of the compounds, such esters being known in the art for modifying solubility and/or hydrolysis characteristics for use as sustained release or prodrug formulations. In addition, some compounds may form solvates with water or common organic solvents. Such solvates are contemplated as well. Both L and D isomers of compounds possessing chiral properties are contemplated by the present invention. Racemic mixtures of compounds are also within the scope of the present invention. The pharmaceutical compositions containing compounds may be in a form suitable for oral use, for example, as tablets, troches, lozenges, aqueous or oily suspensions, dispersible powders or granules, emulsions, hard or soft capsules, or syrups or elixirs. Compositions intended for oral use may be prepared according to any known method, and such compositions may contain one or more agents selected from the group consisting of sweetening agents, flavoring agents, coloring agents and preserving agents in order to provide pharmaceutically elegant and palatable preparations. Tablets may contain the active ingredient in admixture with non-toxic pharmaceutically acceptable excipients which are suitable for the manufacture of tablets. These excipients maybe for example, inert diluents, such as calcium carbonate, sodium carbonate, lactose, calcium phosphate or sodium phosphate; granulating and disintegrating agents, for example, com starch, or alginic acid; binding agents, for example starch, gelatin or acacia; and lubricating agents, for example magnesium stearate, stearic acid or talc. The tablets may be uncoated or they may be coated by known techniques to delay disintegration and absorption in the gastrointestinal tract and thereby provide a sustained action over a longer period. For example, a time delay material such as glyceryl monostearate or glyceryl distearate may be employed. They may also be coated by the techniques described in the U.S. Patents 4,256,108; 4,166,452; and 4,265,874 to form osmotic therapeutic tablets for controlled release. Formulations for oral use may also be presented as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent, for example, calcium carbonate, calcium phosphate or kaolin, or as soft gelating capsules wherein the active ingredient is mixed with water or an oil medium, for example peanut oil, liquid paraffin, or olive oil. Aqueous suspensions may contain the active compounds in admixture with excipients suitable for the manufacture of aqueous suspensions. Such excipients are suspending agents, for example sodium carboxymethylcellulose, methylcellulose, hydroxypropylmethylcellulose, sodium alginate, polyvinylpyrrolidone, gum tragacanth and gum acacia; dispersing or wetting agents may be a naturally-occurring phosphatide, for example lecithin, or condensation products of an alkylene oxide with fatty acids, for example polyoxyethylene stearate, or condensation products of ethylene oxide with long chain aliphatic alcohols, for example heptadecaethyl-eneoxycetanol, or condensation products of ethylene oxide with partial esters derived from fatty acids and a hexitol such as polyoxyethylene sorbitol monooleate, or condensation products of ethylene oxide with partial esters derived from fatty acids and hexitol anhydrides, for example polyethylene sorbitan monooleate. The aqueous suspensions may also contain one or more preservatives, for example ethyl, or n-propyl, p-hydroxybenzoate, one or more coloring agents, one or more flavoring agents, and one or more sweetening agents, such as sucrose or saccharin. Oily suspensions may be formulated by suspending the active ingredient in a vegetable oil, for example arachis oil, olive oil, sesame oil or coconut oil, or in a mineral oil such as liquid paraffin. The oily suspensions may contain a thickening agent, for example beeswax, hard paraffin or cetyl alcohol. Sweetening agents such as those set forth herein, and flavoring agents may be added to provide a palatable oral preparation. These compositions may be preserved by the addition of an anti-oxidant such as ascorbic acid. Dispersible powders and granules suitable for preparation of an aqueous suspension by the addition of water provide the active compound in admixture with a dispersing or wetting agent, suspending agent and one or more preservatives. Suitable dispersing or wetting agents and suspending agents are exemplified by those already mentioned above. Additional excipients, for example sweetening, flavoring and coloring agents, may also be present. The pharmaceutical compositions of the invention may also be in the form of oil-in- water emulsions. The oily phase may be a vegetable oil, for example olive oil or arachis oil, or a mineral oil, for example liquid paraffin or mixtures of these. Suitable emulsifying agents may be naturally-occurring gums, for example gum acacia or gum tragacanth, naturally-occurring phosphatides, for example soy bean, lecithin, and esters or partial esters derived from fatty acids and hexitol anhydrides, for example sorbitan monooleate, and condensation products of the said partial esters with ethylene oxide, for example polyoxyethylene sorbitan monooleate. The emulsions may also contain sweetening and flavoring agents. Syrups and elixirs may be formulated with sweetening agents, for example glycerol, propylene glycol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative and flavoring and coloring agents. The pharmaceutical compositions maybe in the form of a sterile injectable aqueous or oleaginous suspension. This suspension may be formulated according to the known art using those suitable dispersing or wetting agents and suspending agents which have been mentioned above. The sterile injectable preparation may also be a sterile injectable solution or suspension in a non-toxic parenterally-acceptable diluent or solvent, for example as a solution in 1,3- butane diol. Among the acceptable vehicles and solvents that may be employed are water, Ringer's solution and isotonic sodium chloride solution. In addition, sterile, fixed oils are conventionally employed as a solvent or suspending medium. For this purpose any bland fixed oil may be employed including synthetic mono- or diglycerides. In addition, fatty acids such as oleic acid find use in the preparation of injectables. The compositions may also be in the form of suppositories for rectal administration of the PTPase modulating compound. These compositions can be prepared by mixing the drug with a suitable non-irritating excipient that is solid at ordinary temperatures but liquid at the rectal temperature and will therefore melt in the rectum to release the drag. Such materials are cocoa butter and polyethylene glycols, for example. The pharmaceutical forms suitable for injectable use include sterile aqueous solutions or dispersions and sterile powders for the extemporaneous preparation of sterile injectable solutions or dispersions. In all cases the form may be sterile and may be fluid to the extent that easy syringability exists. It may be stable under the conditions of manufacture and storage and can be preserved against the contaminating action of microorganisms, such as bacteria and fungi. The carrier may be a solvent or dispersion medium containing, for example, water, ethanol, polyol (for example, glycerol, propylene glycol, and liquid polyethylene glycol, and the like), suitable mixtures thereof, and vegetable oils. The proper fluidity can be maintained, for example, by the use of a coating, such as lecithin, by the maintenance of a given particle size in the case of dispersion and by the use of surfactants. The prevention of the action of microorganisms can be brought about by various antibacterial and antifungal agents, for example, parabens, chlorobutanol, phenol, sorbic acid, thimerosal, and the like. In many cases, it will be preferable to include isotonic agents, for example, sugars or sodium chloride. Prolonged absorption of the injectable compositions can be brought about by the use in the compositions of agents delaying absorption, for example, aluminum monostearate and gelatin. Therapeutic formulations of the compositions useful for practicing the present invention such as mTOR or PDGF-R inhibitor polypeptides, polynucleotides, or antibodies may be prepared for storage by mixing the selected composition having the desired degree of purity with optional physiologically pharmaceutically-acceptable carriers, excipients, or stabilizers (Remington's Pharmaceutical Sciences, 18th edition, A. R. Gennaro, ed., Mack Publishing Company (1990)) in the form of a lyophilized cake or an aqueous solution. Acceptable carriers, excipients or stabilizers are nontoxic to recipients and may be inert at the dosages and concentrations employed, and include buffers such as phosphate, citrate, or other organic acids; antioxidants such as ascorbic acid; low molecular weight polypeptides; proteins, such as serum albumin, gelatin, or immunoglobulins; hydrophilic polymers such as polyvinylpyrrolidone; amino acids such as glycine, glutamine, asparagine, arginine or lysine; monosaccharides, disaccharides, and other carbohydrates including glucose, mannose, or dextrins; chelating agents such as EDTA; sugar alcohols such as mannitol or sorbitol; salt-forming counterions such as sodium; and/or nonionic surfactants such as Tween, Pluronics or polyethylene glycol (PEG). The composition to be used for in vivo administration may be sterile. This is readily accomplished by filtration through sterile filtration membranes, prior to or following lyophilization and reconstitution. The composition for parenteral administration ordinarily will be stored in lyophilized form or in solution. Therapeutic compositions may be placed into a container having a sterile access port, for example, an intravenous solution bag or vial having a stopper pierceable by a hypodermic injection needle. The route of administration of the composition is in accord with known methods, e.g. oral, injection or infusion by intravenous, intraperitoneal, intracerebral, intramuscular, intraocular, intraarterial, or intralesional routes, or by sustained release systems or implantation device. Where desired, the compositions may be administered continuously by infusion, bolus injection or by implantation device. Suitable examples of sustained-release preparations include semipermeable polymer matrices in the form of shaped articles, e.g. films, or microcapsules. Sustained release matrices include polyesters, hydrogels, polylactides (U.S. Pat No. 3,773,919, EP 58,481), copolymers of L-glutamic acid and gamma ethyl-L- glutamate (Sidman, et al, Biopolymers, 22: 547-556 (1983)), poly (2-hydroxyethyl- methacrylate) (Langer, et al, J. Biomed. Mater. Res., 15:167-277 (1981) and Langer, Chem. Tech., 12:98-105 (1982)), ethylene vinyl acetate (Langer, et al, supra) or poly-D(-)-3-hydroxybutyric acid (EP 133,988). Sustained-release compositions also may include liposomes, which can be prepared by any of several methods known in the art (e.g., DE 3,218,121; Epstein, et al, Proc. Natl. Acad. Sci. USA, 82:3688-3692 (1985); Hwang, et al, Proc. Natl. Acad. Sci. USA, 77:4030-4034 (1980); EP 52,322; EP 36,676; EP 88,046; EP 143,949). An effective amount of the compositions to be employed therapeutically will depend, for example, upon the therapeutic objectives, the route of administration, and the condition of the subject. Accordingly, the therapist may titer the dosage and modify the route of administration to obtain the optimal therapeutic effect. A typical daily dosage may range from about lμg/kg to up to 100 mg/kg or more, depending on the factors mentioned above. Typically, a clinician will administer the composition until a dosage is reached that achieves the desired effect. DOSAGE The frequency of dosing and pharmaceutical formulation are based on the pharmacokinetic parameters of the agents and the routes of administration. See e.g., Remington's Pharmaceutical Sciences, 18th Ed. (1990, Mack Publ. Co, Easton PA 18042) pp 1435-1712, incorporated herein by reference. Such formulations may influence the physical state, stability, rate of in vivo release and rate of in vivo clearance of the administered agents. Depending on the route of administration, a suitable dose may be calculated according to body weight, body surface areas or organ size. Further refinement of the calculations to determine the appropriate treatment dose is routinely made as part of any medical treatment regimen, especially in view of the dosage information and assays disclosed herein as well as the pharmacokinetic data observed in animals or human clinical trials. Dosage consideration may also be guided by pharmaceutical references, see, e.g., Physician's Desk Reference (Montvale, NJ), which is incorporated by reference in its entirety. Dosing in humans may be extrapolated from animal dosages, toxicity studies, and pharmacokinetics, according to standard pharmacological methodologies. Dosing may also be calculated by means of a dose response study, e.g., on dialysis patients such as described in Example 14. Each group either receives a placebo or a combination of a mTOR inhibitor and a PDGF-R inhibitor (combination therapy). Subject combination therapy groups differ in the dosage of one or both inhibitors. Dosages for the mTOR inhibitor (e.g., rapamycin) can range between about 0.25 mg/day and about 3 mg/day; dosages for the PDGF-R inhibitor (e.g., imatinib mesylate) may range between 200 mg/day and 800 mg/day. Applicable ranges also include those described elsewhere herein and as determined based on the subject population of a particular experimental study. Data, e.g., flow rate data, from the experiment are then analyzed to see what combination level(s) yields the optimal physiological signs, e.g., relevant flow rate, and also considering combination levels that in result lower side effects. When the two compounds are given orally to adult subjects to inhibit, prevent, or treat atherosclerosis, to inhibit, prevent, or treat restenosis (or stenosis) after endovascular surgery, to inhibit, prevent, or treat allograft arteriosclerosis and accelerated atherosclerosis (in recipient) and to inhibit, prevent, or treat vasculopathy in other indications listed in the applications, PDGF-R inhibitor (e.g. imatinib mesylate or an equivalent salt) is given approximately 400-600 mg/d and mTOR inhibitor (e.g. sirolimus, everolimus) approximately 1-3 mg/d (targeting to blood maintenance trough levels of 10- 20 ng/ml, chromatographic determinations). For other vascular indications, similar dose levels 1-3 mg/d could also suffice. Clinical trials may show that the combination therapy especially for inhibition or prevention may need even smaller dosages. hi some embodiments, the amount of rapamycin is greater than 0.25 mg/day, but less than about 3 mg/day, and the amount of imatinib mesylate is greater than 200 mg/day, but less than about 800 mg/day. In some embodiments, the amount of rapamycin is at least about 0.5 mg/day, but less than about 3 mg/day, and the amount of imatinib mesylate is at least about 200 mg/day, but less than about 800 mg/day, hi some embodiments, the amount of rapamycin is at least about 0.5 mg/day, but less than about 15 mg/day, and the amount of imatinib mesylate is about 200 mg/day, but less than about 800 mg/day. Dosage ranges for the mTOR inhibitor (e.g., rapamycin) may have a daily low range end of about 1 nanogram (ng), lOng, 50ng, lOOng, 250ng, 500ng, 750ng, 1 microgram (μg), lOμg, 50μg, lOOμg, 250μg, 500μg, 750μg, lmg, 1.25 mg, 1.5 mg, 1.75mg, 2mg, 2.25mg, 2.5mg, 2.75mg, 3mg, 3.25mg, 3.5mg, 3.75mg, 4mg, 4.5mg, 5mg, 5.5mg, 6mg, 7mg, 8mg, 9mg, 10 mg, or an intermediate amount. Dosage ranges for the mTOR inhibitor (e.g. , rapamycin) may have a daily high range end of about lOng, 50ng, lOOng, 250ng, 500ng, 750ng, 1 microgram (μg), lOμg, 50μg, lOOμg, 250μg, 500μg, 750μg, lmg, 1.25 mg, 1.5 mg, 1.75mg, 2mg, 2.25mg, 2.5mg, 2.75mg, 3mg, 3.25mg, 3.5mg, 3.75mg, 4mg, 4.5mg, 5mg, 5.5mg, 6mg, 7mg, 8mg, 9mg, 10 mg, or an intermediate amount. Dosage ranges for the PDGF-R inhibitor (e.g., imatinib mesylate) may have a daily low range end of about lmg, 5mg, lOmg, 25mg, 50mg, 75mg, lOOmg,

125mg, 150mg, 175mg, 200mg, 225mg, 250mg, 275mg, 300mg, 325mg, 350mg, 375mg, 400mg, 425mg, or 450mg, 475mg, 500mg, 525mg, 550mg, 575mg, 600mg, 625mg, 650mg, 675mg, 700mg, 725mg, 750mg, 775mg, 800mg, 825mg, 850mg, 875mg, 900mg, 925mg, 950mg, 975mg, lg, or an intermediate amount. Dosage ranges for the PDGF-R inhibitor (e.g. , imatinib mesylate) may have a daily high range end of about 2mg, 5mg, lOmg, 25mg, 50mg, 75mg, lOOmg, 125mg, 150mg, 175mg, 200mg, 225mg, 250mg, 275mg, 300mg, 325mg, 350mg, 375mg, 400mg, 425mg, or 450mg, 475mg, 500mg, 525mg, 550mg, 575mg, 600mg, 625mg, 650mg, 675mg, 700mg, 725mg, 750mg, 775mg, 800mg, 825mg, 850mg, 875mg, 900mg, 925mg, 950mg, 975mg, lg, or an intermediate amount. In some embodiments, where the two compounds are impregnated in a stent or balloon catheter, the optimal mix ratio may be 1 mg of mTOR inhibitor (e.g. sirolimus, everolimus) and 10 mg of PDGF-R (receptor tyrosine kinase (RTK)) inhibitor (e.g. imatinib mesylate or an equivalent salt thereof). The use of other compounds with similar biological effects may somewhat vary, depending on their affinities on the PDGF- R tyrosine kinase and mTOR. In some embodiments, the two compounds may be given orally to subjects to inhibit or prevent restenosis after endovascular surgery, to inhibit or prevent allograft arteriosclerosis and accelerated atherosclerosis (in recipient) and to inhibit or prevent vasculopathy in other indications listed in the applications. In some embodiments, the PDGF-R inhibitor (e.g. imatinib) may be 6-10 mg/kg/d (approximately 400 - 600 mg/d per subject), hi some embodiments, imatinib, which is relatively non- toxic, is employed with doses of up to about two times the clinical recommended dose. h some embodiments, the mTOR inhibitor (e.g. sirolimus, everolimus), (e.g., in clinical transplants) the loading dose maybe 0.1 mg/kg (6mg/subject), reduced by 2mg/d until dose levels of 1 -3 mg/d and blood maintenance trough levels of 12-20 ng/ml (chromatographic determinations) are eventually obtained, hi some embodiments, e.g., vascular indications, similar dose levels 1-3 mg/d may suffice for mTOR inhibitors. mTOR inhibitors maybe more toxic than PDGF-R, and the instructions of the companies providing sirolimus (Wyeth) and everolimus (Novartis), do not generally recommend any higher dosages, instructions are incorporated herein in their entirety. To inhibit or prevent allograft arteriosclerosis and accelerated atherosclerosis in the recipient, RTK inhibitor maybe administered for 6-12 months combined with unlimited maintenance with m-TOR inhibitor (for immunosuppression). The therapeutic combination may be administered for any range of time, and if necessary may be administered as long as the symptoms, disease, or disorder remains in the subject. In some embodiments, the therapeutic combination is administered so that during a period of certain treatment both a mTOR inhibitor and a PDGF-R inhibitor are administered and during another period of the same treatment only one of the two compounds is administered. In some embodiments, the subject is already on one of the compounds of the combination therapy, and is then started another one (or more) of the compounds of the combination therapy. Dosages may be varied during the course of treatment. For example, the dosages maybe adjusted if the subject encounters side effects, develops unrelated complications, and/or has a change in the kind, dosage, and/or administration of one or more medications other than those of the combination therapy. Administration to a subj ect of the combination therapy may be begun before, during, or after a particular procedure on the subject, e.g., dialysis, organ or tissue transplantation, medical device implantation, vascular surgery, or angioplasty. In some embodiments, the combination therapy is started as early as immediately, 15 minutes (min)., 30 min., 1 hour(s) (hr.), 1 V₂ hr., 2hr., 2 y₂ hr., 3hr., 4 hr., 5hr., 6hr., 7hr., 8hr., 9hr., lOhr., llhr., 12hr., 16hr., 18hr., 20hr., 22hr., 24 hr., 36hr., 48hr., 60hr., 72hr., 84hr., 96, hr., 5 days, 6, days, 10 days, 13 days, 1 week, 2 weeks, three weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, 12 weeks, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, 18 months 20 months, 22 months, 1 year, 2 years, 3 years, 4 years, 5 years, 10 years, 20 years, 25 years, 30 years, 35 years, 40 years, or an intermediate length of time prior to a particular procedure. In some embodiments, the combination therapy is continued for, 15 minutes (min)., 30 min., 1 hour(s) (hr.), 1 ^lA hr., 2hr., 2 y₂ hr., 3hr., 4 hr., 5hr., 6hr., 7hr., 8hr., 9hr., lOhr., llhr., 12hr., 16hr., 18hr., 20hr., 22hr., 24 hr., 36hr., 48hr., 60hr., 72hr., 84hr., 96, hr., 5 days, 6, days, 10 days, 13 days, 1 week, 2 weeks, three weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, 12 weeks, 1 month, 2 months, 3 months, 4 months, 5 months, 6 months, 7 months, 8 months, 9 months, 10 months, 11 months, 12 months, 13 months, 14 months, 15 months, 16 months, 17 months, 18 months 20 months, 22 months, 1 year, 2 years, 3 years, 4 year, 5 years, 10 years, 20 years, 25 years, 30 years, 40 years, 50 years, or an intermediate length of time after a particular procedure. The combination therapy and/or one or more of the compounds of the combination therapy may be administered continuously (e.g., via i.v., medical implant such as a stent, collar, etc.), every 15 minutes 30 min., l-hour(s) (hr.), 1 ^lA hr., 2hr., 2 y₂ hr., 3hr., 4 hr., 5hr., 6hr., 7hr., 8hr., 9hr., lOhr., l lhr., 12hr., 16hr., 18hr., 20hr., 22hr., 24 hr., 36hr., 48hr., 60hr., 72hr., 84hr., 96, hr., 5 days, 6, days, 1 week, 2 weeks, three weeks, 4 weeks, 6 weeks, 8 weeks, 10 weeks, 12 weeks, 1 month, 6 months, 1 year, or an intermediate frequency. The compounds of the combination therapy may be administered such that the compounds are both administered over a certain period of time, but not necessarily given together at any given administration time point, hi some embodiments, the combination compounds are administered together at a given time point. More parameters on administration are provided as follows. ADMINISTRATION As one aspect, the invention provides methods of inhibiting neointimal hyperplasia in a human subject comprising steps of identifying a human subject having at least one condition selected from the group consisting of: fibroproliferative vasculopathy, retinopathy, atherosclerosis, atherosclerosis associated complications, accelerated atherosclerosis, chronic rejection, chronic allograft rejection, allograft arteriosclerosis, restenosis, diabetic angiopathy, diabetic microangiopathy, diabetic macroangiopathy, diabetic nephropathy, diabetic retinopathy, vascular angiopathy, and endothelial denudation; and administering to the human subject a composition comprising at least one mTOR inhibitor and at least one PDGF-R inhibitor or a pharmaceutically acceptable salt, hydrate, or prodrug thereof, wherein the composition is administered in an amount effective to inhibit neointimal hyperplasia in the human subject. The identification of appropriate subjects involves selecting individuals who have been medically evaluated and determined to have one or more of the aforementioned list of conditions (or performing a medical examination and diagnosing one or more of the conditions). In some embodiment, the individual, e.g., a human or other mammalian subject, has undergone at least one procedure selected from the group consisting of an organ transplant, a tissue transplant, endovascular surgery, percutaneous transluminal angioplasty, percutaneous transluminal coronary angioplasty, angioplasty, and vascular intervention. In some embodiments, the mammalian subject has suffered endothelial denudation by any number of different causes. The composition(s) is administered in an amount effective to inhibit neointimal hyperplasia in the human subject. While there are many criteria for evaluating the amount of neointimal hyperplasia, it will be apparent to clinicians any appropriate diagnostic techniques may be utilized, including, but not limited to, angiograms, physicals, intravascular ultrasound, blood pressure, flow rate/pressure in dialysis subjects, and medical dyes (which may be used in conjunction with a scope). Likewise, many of the conditions are associated with undesirable symptoms or physical manifestations, and to lessen the severity or occurrence of one or more symptoms associated with a disease state or disorder is also scored as inhibiting neointimal hyperplasia. Human dosing can initially be estimated from animal studies described in the examples herein. Imaging (ultrasound, fluoroscopy, MRI, angiogram, etc.) are available for assessing neointimal hyperplasia in vivo. As indicated herein, any form of administration and pharmaceutical composition is contemplated, with oral administration of pills, powders, capsules, liquids, or food additives may be used. Those of ordinary skill in the art will readily optimize effective dosages and administration regimens as determined by good medical practice and the clinical condition of the individual subject, taking into account such considerations as therapeutic efficacy, risk of toxicity, and side-effects. Appropriate dosages may be ascertained through the use of established assays for determining blood clotting levels in conjunction with relevant dose-response data. The final dosage regimen will be determined by the attending physician, considering factors that modify the action of drugs, e.g., the drag's specific activity, the age, condition, body weight, sex and diet of the subject, time of administration and other clinical factors. As studies are conducted, further information will emerge regarding appropriate dosage levels and duration of treatment for specific diseases and conditions. A therapeutic or prophylactic treatment of restenosis provided by the present invention involves administering to a mammalian subject such as a human a composition comprising a mTOR inhibitor and a PDGF-R inhibitor. The "administering" may be performed using any medically-accepted means for introducing a therapeutic directly or indirectly into the vasculature of a mammalian subject, including but not limited to injections; oral ingestion; intranasal or topical administration; and the like. In some embodiments, administration of the composition comprising the mTOR inhibitor and PDGF-R inhibitor is performed intravascularly, such as by intravenous, intra-arterial, or intracoronary arterial injection. The mTOR inhibitor and PDGF-R inhibitor need not be administered contemporaneously or even on the same day. In some embodiments, the separation in administration of the two inhibitors may be weeks, months or even years. In some embodiments, immunosuppressive calcineurin inhibitors (e.g., tacrolimus, cyclosporine) maybe utilized for the first two months (e.g., after transplantation or vascular injury), followed by use of a mTOR inhibitor (e.g. , rapamycin or everolimus) starting in the third month. As immunosuppressive calcineurin inhibitors may promote vascular injury and neointimal hyperplasia, use of a PDGF-R inhibitor, e.g., imatimb, during the initial two month period may provide vasculoprotection. The long term efficacy of combination therapy using an inhibitor of mTOR with an inhibitor of a PDGF-R lends itself particularly well to implanted medical devices, e.g., stents. However, oral administration may also be used successfully. Means of administration may include, but are not limited to, oral, catheter, percutaneous transluminal angioplasty (PTA), and percutaneous transluminal coronary angioplasty (PTCA). hi some embodiments, one inhibitor may be administered orally and the other locally, e.g., on a coated stent. In some embodiments, the composition is administered locally, e.g., to the site of angioplasty or bypass. For example, the administering comprises a catheter- mediated transfer of the therapeutic composition into a blood vessel of the mammalian subject, especially into a coronary artery of the mammalian subject. Exemplary materials and methods for local delivery are reviewed in Lincoff et al, Circulation, 90: 2070-2084 (1994); and Wilensky et al, Trends Cardiovasc. Med., 3:163-170 (1993), both incorporated herein by reference. For example, the composition is administered using infusion-perfusion balloon catheters (e.g., mircroporous balloon catheters) such as those that have been described in the literature for intracoronary drug infusions. See, e.g., U.S. Patent No. 5,713,860 (Intravascular Catheter with Infusion Array); U.S. Patent No. 5,087,244; U.S. Patent No. 5,653,689; and Wolinsky et al, J. Am. Coll. Cardiol., 15: 475- 481 (1990) (Wolinsky Infusion Catheter); and Lambert et al, Coron. Artery Dis., 4: 469- 475 (1993), all of which are incorporated herein by reference in their entirety. Use of such catheters for site-directed somatic cell gene therapy is described, e.g., in Mazur et al, Texas Heart Institute Journal, 21; 104-111 (1994), incorporated herein by reference. For example, in subjects with angina pectoris due to a single or multiple lesions in coronary arteries and for whom percutaneous transluminal coronary angioplasty (PTCA) is prescribed on the basis of primary coronary angiogram findings, an exemplary protocol involves performing PTCA through a 7F guiding catheter according to standard clinical practice using the femoral approach. If an optimal result is not achieved with PTCA alone, then an endovascular stent also is implanted. (A non-optimal result is defined as residual stenosis of > 30 % of the luminal diameter according to a visual estimate, and B or C type dissection.) Arterial gene transfer at the site of balloon dilatation is performed immediately after the angioplasty, but before stent implantation, using an infusion-perfusion balloon catheter. The size of the catheter will be selected to match the diameter of the artery as measured from the angiogram, varying, e.g., from 3.0 to 3.5F in diameter. The balloon is inflated to the optimal pressure and gene transfer is performed during a 10 minute infusion at the rate of 0.5 ml/min with viras titer of 1.15 X 10¹⁰. h another embodiment, intravascular administration with a gel-coated catheter is contemplated, as has been described in the literature to introduce transgenes or other biologically active compounds. See, e.g., U.S. Patent No. 5,674,192 (Catheter coated with tenaciously-adhered swellable hydrogel polymer); Riessen et al, Human Gene Therapy, 4: 749-758 (1993); and Steg et al, Circulation, 96: 408-411 (1997) and 90: 1648-1656 (1994); all incorporated herein by reference. As shown in Figure 1, a catheter 21 is provided to which an inflatable balloon 23 is attached at a distal end. The balloon includes a swellable hydrogel polymer coating 25 capable of absorbing a solution comprising a therapeutic composition comprising a mTOR inhibitor and a PDGF-R inhibitor. Briefly, the composition is applied one or more times ex vivo to the surface of an inflated angioplasty catheter balloon coated with a hydrogel polymer (e.g., Slider with Hydroplus, Mansfield Boston Scientific Corp., Watertown, MA). The Hydroplus coating is a hydrophilic polyacrylic acid polymer that is cross-linked to the balloon to form a high molecular weight hydrogel tightly adhered to the balloon. The composition covered hydrogel is permitted to dry before deflating the balloon. Re-inflation of the balloon intravascularly, during an angioplasty procedure, causes the transfer of the composition, and drags therein, to the vessel wall. Thus, referring again to Figure 1, the catheter with attached, coated balloon is inserted into the lumen 27 of a blood vessel 29 while covered by a protective sheath 31 to minimize exposure of the coated balloon to the blood prior to placement at the site of an occlusion 33. When the instrument has been positioned at the treatment region, the protective sheath is drawn back or the catheter is moved forward to expose the balloon, which is inflated to compress the balloon (and thus the coating) into the vessel wall, causing transfer of the therapeutic agents (e.g., the mTOR inhibitor and PDGF-R inhibitor) to the tissue, in a manner analogous to squeezing liquid from a compressed sponge or transferring wet paint to a surface by contact. In yet another embodiment, an expandable elastic membrane, film, or similar stracture, mounted to or integral with a balloon angioplasty catheter or stent, is employed to deliver the mTOR inhibitor and PDGF-R inhibitor therapeutic agents. See, e.g., U.S. Patent Nos. 5,707,385, 5,697,967, 5,700,286, 5,800,507, and 5,776,184, all incorporated by reference herein. As shown in Figures 2A-2B, a single layer 41 or multi- layer 41, 43 sheet of elastic membrane material (Fig. 2A) is formed into a tubular structure 45 (Fig. 2B), e.g., by bringing together and adhering opposite edges of the sheet(s), e.g., in an overlapping or a abutting relationship, hi this manner the elastomeric material may be wrapped around a catheter balloon or stent. A therapeutic mTOR inhibitor, PDGF-R inhibitor composition is combined with the membrane using any suitable means, including injection molding, coating, diffusion, and absorption techniques, hi the multilayer embodiment depicted in the figures, the edges of the two layers may be joined to form a fluid-tight seal. In some embodiments, one layer of material is first processed by stretching the material and introducing a plurality of microscopic holes or slits 47. After the layers have been joined together, the sheet can be stretched and injected with the therapeutic composition through one of the holes or slits to fill the cavity that exists between the layers. The sheet is then relaxed, causing the holes to close and sealing the therapeutic composition between the layers until such time as the sheet is again stretched. This occurs, for example, at the time that an endovascular stent or balloon covered by the sheet is expanded within the lumen of a stenosed blood vessel. The expanding stent or balloon presses radially outward against the inner surface 49 of the tubular sheet covering, thus stretching the sheet, opening the holes, and delivering the therapeutic agent to the walls of the vessel. hi another variation, the composition containing the mTOR inhibitor, PDGF-R inhibitor therapeutic is administered extravascularly, e.g., using a device to surround or encapsulate a portion of vessel. See, e.g., Intemational Patent Publication WO 98/20027, incorporated herein by reference, describing a collar that is placed around the outside of an artery (e.g., during a bypass procedure) to deliver a transgene or other biologically active compound to the arterial wall via a plasmid or liposome vector or deliver other biologically active compounds. As shown in FIGS. 3A and 3B, an extravascular collar 51 including a void space 53 defined by a wall 55 formed, e.g., of a biodegradable or biocompatible material. The collar touches the wall 57 of a blood vessel 59 at the collar's outer extremities 61. Blood 63 flows through the lumen 62 of the blood vessel. A longitudinal slit 65 in the flexible collar permits the collar to be deformed and placed around the vessel and then sealed using a conventional tissue glue, such as a thrombin glue. hi some embodiments in which either or both of the mTOR and PDGF-R inhibitor is a polypeptide (or nucleic acid encoding the same), endothelial cells or endothelial progenitor cells are transfected ex vivo with the relevant transgene, and the transfected cells as administered to the mammalian subject. Exemplary procedures for seeding a vascular graft with genetically modified endothelial cells are described in U.S. Patent No. 5,785,965, incorporated herein by reference. If the mammalian subject is receiving a vascular graft, the mTOR inhibitor, PDGF-R inhibitor therapeutic composition may be directly applied to the isolated vessel segment prior to its being grafted in vivo. In some embodiments, the administering comprises implanting an intravascular stent in the mammalian subject, where the stent is coated or impregnated with the therapeutic mTOR inhibitor, PDGF-R inhibitor composition. Exemplary materials for constructing a drag-coated or drag-impregnated stent are described in literature cited above and reviewed in Lincoff et al, Circulation, 90: 2070-2084 (1994). As shown in Figure 4A and 4B, a metal or polymeric wire 81 for forming a stent is coated with a composition 83 such as a porous biocompatible polymer or gel that is impregnated with (or can be dipped in or otherwise easily coated immediately prior to use with) a mTOR inhibitor, PDGF-R inhibitor therapeutic composition. The wire is coiled, woven, or otherwise formed into a stent 85 suitable for implantation into the lumen of a vessel using conventional materials and techniques, such as intravascular angioplasty catheterization. Exemplary stents that may be improved in this manner are described and depicted in U.S. Patent Nos. 5,800,507 and 5,697,967 (Medtronic, Inc., describing an intraluminal stent comprising fibrin and an elutable drag capable of providing a treatment of restenosis); U.S. Patent No. 5,776,184 (Medtronic, Inc., describing a stent with a porous coating comprising a polymer and a therapeutic substance in a solid or solid/solution with the polymer); U.S. Patent No. 5,799,384 (Medtronic, Inc., describing a flexible, cylindrical, metal stent having a biocompatible polymeric surface to contact a body lumen); U.S. Patent Nos. 5,824,048 and 5,679,400; and U.S. Patent No. 5,779,729; all of which are specifically incorporated herein by reference in the entirety. Implantation of such stents during conventional angioplasty techniques will result in less restenosis than implantation of conventional stents. In this sense, the biocompatibility of the stent is improved. The inhibitors may be operatively associated with the stent in any manner allowing for suitable drag release. In some embodiments, a polymer or a polymeric matrix is applied to a stent surface. A composition comprising the inhibitors and a polymeric material may further comprise a solvent to allow for coating of the stent surface with evaporation of the solvent providing a layer comprising the inhibitors. The inhibitors may be applied using such techniques at the same time or separately. Single or multiple layers of polymers may be employed, and the inhibitors may be in a common or in different layers; some layers may not comprise an inhibitor, but may still allow passage of an inhibitor through that layer. Different surfaces and/or layers may comprise different inhibitors or share common inhibitors. Such surfaces need not be on the same stent. Micropores, strats or channels, on the stent or other medical device may comprise the inhibitors and a polymer layer may be applied to serve as a means to control release of the inhibitors. The inhibitors may be physically or chemically, e.g., covalently, attached to the stent. As described for surfaces, the inhibitors need not be located in a common portion of the stent. Suitable polymers also include, but are not limited to, biocompatible non- degrading materials such as acrylate based polymers or copolymers, e.g. polybutylmethacrylate, poly(hydroxyethyl methylmethacrylate); cellulose esters e.g. cellulose acetate, cellulose nitrate or cellulose propionate; fluorinated polymers such as polytetrafluoethylene; polyurethane; polyolefins; polyesters; polyamides; polycaprolactame; polyimide; polyvinyl chloride; polyvinyl methyl ether; polyvinyl alcohol or vinyl alcohol/olefin copolymers, e.g. vinyl alcohol/ethylene copolymers; polyacrylonitrile; polystyrene copolymers of vinyl monomers with olefins, e.g. styrene acrylonitrile copolymers, ethylene methyl methacrylate copolymers; polydimethylsiloxane; poly(ethylene-vinylacetate); polyvinyl pyrrolidinone; or mixtures thereof. Suitable polymers also include, but are not limited to, biodegradable polymers such as cellulosic polymers; collagen; fibrin; fibrinogen; gelatin; hyaluronic acid; hydrophilic, hydrophobic or biocompatible biodegradable materials, e.g. polycarboxylic acids; lactone-based polyesters or copolyesters, e.g. polylactide; polyglycolide; polylactide-glycolide; polycaprolactone; polycaprolactone-glycolide; poly(hyάr-oxybutyrate); poly(hydroxyvalerate); polyhydroxy(butyrate-co-valerate); polyglycolide-co-trimethylene carbonate; poly(diaxanone); polyorthoesters; polyanhydrides; polyaminoacids; polysaccharides; polyphospoeters; polyphosphoester- urethane; polycyanoacrylates; polyphosphazenes; poly(ether-ester) copolymers, e.g. PEO- PLLA, starch; or mixtures thereof. In some embodiments, the composition comprises microparticles composed of biodegradable polymers such as PGLA, non-degradable polymers, or biological polymers (e.g., starch) which particles encapsulate or are impregnated by the mTOR inhibitor and the PDGF-R inhibitor. Such particles are delivered to the intravascular wall using, e.g., an infusion angioplasty catheter. Other techniques for achieving locally sustained drug delivery are reviewed in Wilensky et al, Trends Caridovasc. Med., 3.T63-170 (1993), incorporated herein by reference. Administration via one or more intravenous injections subsequent to the angioplasty or bypass procedure also is contemplated. In those embodiments in which the mTOR or PDGF-R inhibitor comprises one or more polypeptides, localization of the mTOR inhibitor and/or the PDGF-R inhibitor to the site of the procedure occurs due to expression of mTOR and PDGF receptors on proliferating endothelial cells. Localization is further facilitated by recombinantly expressing the inhibitors as fusion polypeptides (e.g., fused to an apolipoprotein B-100 oligopeptide as described in Shih et al, Proc. Nat'l Acad. Sci. USA, 57:1436-1440 (1990)). The pharmaceutical efficacy of a combinatorial therapy of a mTOR inhibitor and a PDGF-R inhibitor to inhibit or prevent stenosis or restenosis of a blood vessel and other complications involving neointimal hyperplasia is demonstrated in vivo, e.g., using procedures such as those described in the following examples, some of which are prophetic. The examples assist in further describing the invention, but are not intended in any way to limit the scope of the invention. EXAMPLE 1 SYNERGISTIC SUPPRESSION OF RAT NEOINTIMAL HYPERPLASIA BY RAPAMYCIN AND IMATINIB MESYLATE This study employed an animal model, male Wistar rats, of neointimal hyperplasia following aortic denudation achieved using an embolectomy catheter. The animal subjects where given daily doses of rapamycin, imatinib mesylate, both compounds, or a placebo (PBS). The subjects were sacrificed either 14 or 40 days following surgery and relevant tissue examined for neointimal hyperplasia.

Methods Operative method and animal care Complete aortic denudation was performed on male Wistar rats weighing 300-400 g (Harian). Briefly, animals were anaesthetized with 60-80 mg chloral hydrate i.p. having received 60 μg s.c. buprenorphine (Tamgesic®, Schering-Plough) for analgesia. The abdomen was opened in two layers along the linea alba, the left iliac artery was exposed, proximally clamped and distally ligated with 6-0 Silkam (Braun Surgical, Melsungen, GDR). A 2F Fogarty embolectomy catheter was introduced, inflated with 0.2 mL air and passed 5 times between the aortic arch and the iliac bifurcation; it was then withdrawn and the vessel was ligated proximally. The abdominal layers (muscle, skin) were closed with running 3-0 Nicryl (Ethicon) and the animals were left to recover from anesthesia before being medicated for the first time. The animals were housed in pairs for the duration of the study and fed standard chow and water ad libitum. Access to food was not restricted prior to dosing. Humane care was applied in compliance with the Guide for the Care and Use of Laboratory Animals (NTH publication #85-23, revised 1996). Drugs and treatments Prescription formulations of both rapamycin (Rapamune® oral solution, Wyeth- Ayerst) and imatinib mesylate (Glivec® capsules, Novartis), administered orally via a curved gavage needle, were used in this study. Rapamycin was stored in the dark at 4°C and used as described herein and in accordance with standard techniques. Imatinib mesylate was dissolved in PBS at various concentrations (5, 10 or 25 mg/mL), stored 4°C and used within 3 days. Under these conditions imatinib mesylate formed stable, white homogeneous suspensions. Drags were administered at the following doses (all in mg/kg/d):

Rapamycin at 0.5, 1 and 1.5; and imatinib mesylate at 2, 5, 10 and 50. Control animals received PBS. For combination treatment imatinib mesylate was administered first, followed by rapamycin; although the drugs may be administered in the reverse order or simulateneously. All treatments were administered immediately following surgery and once daily thereafter (between 09:00 and 11 :00) for 13 days. All dosing was performed under light inhalation anesthesia ((Isofluran®, Baxter). There were no episodes of reflux or dose leakage. Rapamycin pharmacokinetics On post-operative day 13, rapamycin-treated animals were bled via the tail immediately prior to, and at 2, 4 and 6 hours after, dosing. Bleeding was performed under inhalation anesthesia. Whole blood (~1 mL) was collected in EDTA tubes and promptly stored in the dark, at -20°C pending further analysis. lmL of 0.9% NaCl was administered subcutaneously on each occasion to replenish lost fluids. Left kidneys of rapamycin-treated animals were also harvested following sacrifice, prior to perfusion, and promptly stored as described herein. Rapamycin concentrations in whole blood and tissue were determined by HPLC-UV, according to Maleki S, et al, Clin Ther 2000; 22 Suppl B: B25-B37. Briefly, blood specimens were thawed; 1 mL of each was diluted in sodium acetate buffer, spiked with an internal control (desmethoxysirolimus, Wyeth- Ayerst) and extracted with 1- chlorobutane (Sigma). Kidney specimens were weighed, thawed, and disrupted using a homogenizer and similarly extracted. The organic phase was evaporated to dryness and the residue was resuspended in 70% methanol H₂0; and analyzed on a HPLC apparatus using a C18 column (4.6x150 mm; 3 μm particle size). Histology The animals were sacrificed either 14 or 40 days after aortic injury; dissected under inhalation anesthesia and perfused through the left ventricle with 25 mL cold 3% buffered paraformaldehyde (PFA) under constant pressure (~100 mmHg). After ~45 min the thoracic aorta was harvested in fixative and stored at 4°C for a further 5 hours, at which time it was divided into four segments along its length and transferred into PBS. Heart, stomach, jejunum, liver and kidney specimens were also retrieved from some animals for toxicity studies. All tissues were processed into paraffin, sectioned (2-μm thick), stained and mounted for microscopic evaluation. Imaging was performed using a BX-51 microscope fitted with a DP-50 camera (Olympus); tissue images were captured with Studio Lite 1.0 (Pixera Corp.) and exported to Image-Pro Plus software (Media Cybernetics) for vascular area measurements. Two random, consecutive sections from each of the four segments were evaluated per vessel in order to ensure precise and representative results; these were then averaged for every individual vessel. Cell counts and vascular area measurements were performed independently by three individuals blinded to treatment and to each others' reports. Slides in the toxicity sub-study were further reviewed by a resident pathologist.

Statistics Treatment groups were compared using Student's unpaired t test. Two- tailed p values less than 0.05 were considered statistically significant.

Results Treatment tolerability No animals were lost to follow-up; neither rapamycin nor imatinib mesylate produced signs of overt toxicity (marked weight loss; hair loss; diarrhea; or sickness behavior) at any of the doses used, alone or in combination. When administered individually, each drag dose-dependently inhibited the acute weight loss following surgery; however, only imatinib mesylate (5 and 10 mg/kg/d) significantly promoted weight recovery at 14 days. Animals assigned to the highest does of imatinib mesylate (50 mg/kg/d) did not show any weight gain over this observation period. Heart, stomach, jejunum, liver and renal histology was normal in these animals (not shown). Rats assigned to the medium- and high-dose drag combinations tended to regain weight more slowly than rats in other treatment groups. However, once treatment was halted, the rate of weight gain was virtually identical in all drag-treated groups. Healing of surgical wounds proceeded normally in all animals. Treatment efficacy Both drags independently inhibited neointimal hyperplasia, in a dose- dependent fashion, 14 days after aortic injury (FIG. 5 (rapamycin, "rapa") and FIG. 6 (imatinib mesylate, "glivec")) with rapamycin (ED50=0.63 mg/kg/d) being more potent than imatinib mesylate (ED50=11.2 mg/kg/d) in this respect. Pharmacological and therapeutic interaction in combination regiments of the two drags was subsequently evaluated, on the background of their individual dose- response curves. A low-dose combination ("low combi") of the two agents (rapamycin 0.25 mg/kg/d + imatinib mesylate 2 mg/kg/d) produced a response suggestive of antagonism. Conversely, two higher dose combinations (rapamycin 0.5 or 1 mg/kg/d + imatinib mesylate 10 mg/kg/d, "mid combi" and "hi combi," respectively) indicated a moderate degree of synergism between the two drags (FIG. 7). Pharmacokinetic interactions For imatinib mesylate, the bioavailability after oral administration is 98% and half life 18-40 hrs with no accumulation in repeated administration. Long-term efficacy The long-term effect of a two-week treatment with either drag alone, or the highest dose combination (rapamycin 1 mg/kg/d + imatinib mesylate 10 mg/kg/d), was assessed in aortic tissue retrieved 40 days after vascular injury. (See generally, FIG. 8.) Neointimal lesions in control specimens were typically larger than the respective 14-day lesions, containing abundant extracellular matrix and increased numbers of myofibroblastoid cells. When used individually, rapamycin and imatinib mesylate had no lasting vasculoprotective effect. Conversely, combination therapy resulted in a synergistic effect and sustained and virtually complete suppression of lesion growth (FIG. 8). In contrast to the histological picture seen in control and single drag-treated animals, where neointimal lesions grew both along the periphery and across the lumen, "lesions" developing under early combination therapy remained small and focal. EXAMPLE 2 USE OF AN MTOR INHIBITOR AND PDGF-R INHIBITOR TO INHIBIT OR PREVENT RESTENOSIS A. Materials and Methods 1. Pharmaceutical Compositions Compositions as outlined in Example 1 are appropriate. 2. Animal Model New Zealand White rabbits may be employed for the study. A first group of rabbits is fed a 0.25 % cholesterol diet for two weeks, then subjected to balloon denudation of the aorta, then administered medication starting three days later to experimental or control animals and continuing until and including the thirteenth day. A second group of rabbits is only subjected to experimental or control dosages of medication. Animals are sacrificed 14 or 40 days after beginning the administration of the medication. The number of experimental (mTOR and PDGF-R inhibitors) and control (placebo, mTOR inhibitor alone, PDGF-R inhibitor alone) animals in each group may include at least six animals. In the first group of rabbits, the whole aorta, beginning from the tip of the arch, is denuded using a 4.0 F arterial embolectomy catheter (Sorin Biomedical, Irvine, CA). The catheter is introduced via the right iliac artery up to the aortic arch and inflated, and the aorta was denuded twice. 3. Administration of Experimental and Control Medications Administration may be by any means generally understood in the art, including, but not limited to the types of administration described herein. 4. Histology Three hours before sacrifice, the animals are injected intravenously with 50 mg of BrdU dissolved in 40% ethanol. After the sacrifice, the aortic segment where the denudation had been performed is removed, flushed gently with saline, and divided into five equal segments. The proximal segment is snap frozen in liquid nitrogen and stored at -70° C. The next segment is immersion-fixed in 4% paraformaldehyde / 15% sucrose (pH 7.4) for 4 hours, rinsed in 15% sucrose (pH 7.4) overnight, and embedded in paraffin. The medial segment is immersion-fixed in 4% paraformaldehyde / phosphate buffered saline (PBS) (pH 7.4) for 10 minutes, rinsed 2 hours in PBS, embedded in OCT compound (Miles), and stored at -70 °C. The fourth segment is immersion-fixed in 70% ethanol overnight and embedded in paraffin. The distal segment is immersion-fixed in 4% paraformaldehyde / 15% sucrose (pH 7.4) for 4 hours, rinsed in 15% sucrose overnight, and embedded in paraffin. Paraffin sections are used for immunocytochemical detection of smooth muscle cells (SMC), macrophages, and endothelium. BrdU-positive cells are detected according to manufacturer's instructions. Morphometry is performed using haematoxylin-eosin stained paraffin sections using image analysis software. Measurements are taken independently by two observers from multiple sections, without knowledge of the origin of the sections. Intima/media (I/M) ratio are used as a parameter for intimal thickening. B. Results Restenosis (and/or stenosis) is expected to be inhibited in those animals receiving both the mTOR inhibitor and PDGF-R inhibitor to a degree that is more than would be expected from the additive effects of the two inhibitors, which may depend on the amount of each inhibitor administered. Restenosis (and/or stenosis) inhibition or prevention maybe based on the quantity of neointimal nuclei as described in Example 1 or using other appropriate techniques including without limitation those discussed herein, see, e.g., Example 6. EXAMPLE 3 USE OF AN INHIBITOR OF MTOR AND AN INHIBITOR OF A PDGF-R TO INHIBIT OR PREVENT RESTENOSIS FOLLOWING ANGIOPLASTY WITH STENT IMPLANTATION The procedures described in Example 1 and/or 2 are repeated with the modification that initial balloon angioplasty is accompanied by implantation of a coronary or peripheral stent using conventional procedures. The mTOR and PDGF-R inhibitors are delivered concurrently or immediately before or after stent implantation essentially as described in the preceding examples. In some variations, the stent is coated with the inhibitor of mTOR and the inhibitor of a PDGF-R is administered orally, or vice versa. In some variations both inhibitors may be coated on the stent. Decreased neointimal thickening and/or decreased thrombotic occlusion in the dual inhibitor-treated animals versus control subjects is considered evidence of the efficacy of the dual inhibitor therapy. Other suitable criteria including without limitation those described herein may also be used to judge the effectiveness of the treatment. In some variations, in order to show the long term efficacy (lasting effect) of the treatment, the stent is removed at a particular time point (or in the alterative loaded with amounts of inhibitors, so that the inhibitors are exhausted after a particular time point), and that time point may be varied amongst the subjects within a group or between different groups, hi such variations, the degree of occlusion may be measured at time points (e.g., every week, month, year) after cessation of the inhibitor administration. EXAMPLE 4 USE OF AN EXTRAVASCULAR COLLAR TO REDUCE VASCULAR STENOSIS. An inert silicone collar such as described in Intemational Patent Publication No. WO 98/20027 is surgically implanted around the carotid arteries of New Zealand White Rabbits. The collar acts as an irritation agent that will induce intimal thickening, and contains a reservoir suitable for local delivery of an mTOR inhibitor and PDGF-R inhibitor pharmaceutical formulation. Dual inhibitor formulation or control formulations, e.g., as described in Example 1, is initiated five days later by injecting the given formulation into the collar. Animals are sacrificed 14 or 28 days later and histological examinations are performed as described in Example 1 and/or 2. Intima/media thickness ratio [Yla-Herttuala et al, Arteriosclerosis, 6: 230-236 (1986)] may be used as an indicia of stenosis. Reduced I/M ratio in the dual inhibitor treated subjects, as compared to the control subjects, indicates therapeutic efficacy of the dual inhibitor treatment for inhibiting or preventing arterial stenosis (and/or restenosis). Criteria as described in Examples 1 and 6 may also be employed. In some variations, in order to show the long term efficacy (lasting effect) of the treatment, the collar is removed at a particular time point (or in the alterative loaded with amounts of inhibitors, so that the inhibitors are exhausted after a particular time point), and that time point may be varied amongst the subjects within a group or between different groups. In such variations, the degree of occlusion may be measured at time points (e.g., every week, month, year) after cessation of the inhibitor administration. EXAMPLE 5 MTOR INHIBITOR, PDGF-R INHIBITOR AND TREATMENT OF ANGIOPLASTY SUBJECTS The purpose of this example is to demonstrate the benefits of treating subjects, who have undergone angioplasty and/or have received a vascular or coronary stent, to help inhibit or prevent restenosis. Subjects, having undergone angioplasty are divided into four groups. One group is given a straight control, one group is given a mTOR inhibitor, e.g. rapamycin, one group is given a PDGF-R inhibitor, e.g., imatinib mesylate, and one group is given both a mTOR inhibitor and a PDGF-R inhibitor (e.g., both rapamycin and imatinib mesylate). In non-human animals, the straight control may comprise inert substances, hi humans, the straight control may comprise, for example, a non-mTOR inhibitor, hi some variations, a mTOR inhibitor may be employed as the straight control, but at levels higher that that used in the combination group. Subjects are generally grouped by sex, weight, age, and medical history to help minimize variations among subjects. Dosages as discussed above in Example 1 or in the "Dosage" section may be employed. For example, PDGF-R inhibitor (e.g. imatinib mesylate) 6-10 mg/kg/d (approximately 400-600 mg/d per subject). For mTOR inhibitor (e.g. sirolimus, everolimus), the loading dose is 0.1 mg/kg (6mg/subject), reduced by 2mg/d until dose levels of 1-3 mg/d and blood maintenance trough levels of 12-20 ng/ml (chromatographic determinations) are eventually obtained. Administration may begin before, after or concurrent with the transplantation. Duration of administration can be as described herein or for any other relevant period. The study may involve examinations at zero point, at six months, at one year, and optionally the subjects may be examined using any appropriate technique and criteria including without limitation intravascular ultrasound, and those techniques discussed in Example 6 and elsewhere herein. Improvements may be evaluated using statistical analysis of the data, e.g., with ANOVA t-tests or student t-tests. Significant improvement over any parameter used to assess treatment for stenosis, restenosis, or neointimal thickening (neointimal hyperplasia) provides an indication that the combinatorial therapy of a mTOR inhibitor and PDGF-R inhibitor is beneficial. Methodologies for assessing the success of the treatment are also discussed in more detail in Example 6. In some variations, in order to show the long term efficacy (lasting effect) of the treatment, the inhibitor administration is ceased at a particular time point, and that time point may be varied amongst the subjects within a group or between different groups. To control for variables, administration of an experimental formulation may be replaced with a control formulation, or one control formulation with another, upon cessation of the initial administration period. In the aforementioned variations, the amount of neointimal thickening and/or other parameters maybe measured at time points (e.g., every week, month, year) after cessation of the inhibitor administration. EXAMPLE 6 MTOR INHIBITOR, PDGF-R INHIBITOR AND TREATMENT OF TRANSPLANT RECIPIENTS The purpose of this example is to demonstrate the benefits of treating subjects, who have undergone an organ or tissue transplants or transplant of artificial devices. In some embodiments, a vessel or portion of a vessel is transplanted. The transplant recipients are divided into four groups. One group is given a straight control (e.g., as discussed in Example 5), one group is given a mTOR inhibitor, e.g. rapamycin, one group is given a PDGF-R inhibitor, e.g., imatimb mesylate, and one group is given both a mTOR inhibitor and a PDGF-R inhibitor (e.g., both rapamycin and imatinib mesylate). An non-mTOR inhibitor immunosuppressant may be used to treated graft versus host disease (GNHD). Such an immunosuppressant may be added to the other groups as well so as to minimize the number of variables between the different groups. In addition or in the alternative, subjects may be generally grouped by sex, weight, age, and medical history to help minimize variations among subjects. Dosages as discussed in Example 1 or in the "Dosage" section may be employed. For example, PDGF-R inhibitor (e.g. imatimb mesylate) 6-10 mg/kg/d (approximately 400-600 mg/d per subject). For mTOR inhibitor (e.g. sirolimus, everolimus), the loading dose is 0.1 mg/kg (6mg/subject), reduced by 2mg/d until dose levels of 1-3 mg/d and blood maintenance trough levels of 12-20 ng/ml (chromatographic determinations) are eventually obtained. Administration may begin before, after or concurrent with the transplantation. Duration of administration can be as described herein or for any other relevant period. The study may involve examinations at zero point, at six months, at one year, and optionally the subjects maybe examined using any appropriate technique and criteria including without limitation intravascular ultrasound (e.g., power Doppler), angiograms, MRI, blood pressure, physicals and any other means of assessing the vascular health of the subject, hi particular, the existence or progression of transplant arteriosclerosis and/or accelerated atherosclerosis may be followed. Biopsies may be performed periodically, e.g., every six months, e.g., at surgery, at one year and at three years. Progression of vascular disease, rejection and major vascular events are recorded. Improvements maybe evaluated using statistical analysis of the data, e.g., with ANONA t-tests or student t-tests. Significant improvement over any parameter used to assess the inhibition or prevention of stenosis, restenosis, or neointimal thickening (neointimal hyperplasia), e.g., maintenance of blood flow, provides an indication that the combinatorial therapy of a mTOR inhibitor and PDGF-R inhibitor is beneficial. In some variations, the transplant study involves a primate kidney transplant model. Such model studies are described throughout the literature. See, e.g., Birsan, et al, Transplantation, 75(12):2106-13; Yuzawa et al, Transplantation, 75(9):1463-8 (2003); Qi, et al, Transplantation, 75(8):1124-8 (2003); Yang, et al, Transplantation 75(8): 1166-71 (2003); Gaschen and Shuurman, Brit. J. Radiology, 74:411-419 (2001); and Schuurman, et al, Transplantation, 69(5):737-42 (2000). These models may be adapted using the methods, dosages, and compositions described herein. hi some variations, subgroups within one or more of the groups is established with individuals receiving varying amounts of one or more inhibitor. In some embodiments, subgroups may be established, such that the drug regimen is suspended at different time points for each subgroup within a group to investigate the lasting effects of the regimen. Such subgroups may also be established for the groups described in the other examples described herein. For example, in order to show the long term efficacy (lasting effect) of the treatment, the inhibitor administration is ceased at a particular time point, and that time point may be varied amongst the subjects within a group or between different groups. To control for variables, administration of an experimental formulation may be replaced with a control formulation, or one control formulation with another, upon cessation of the initial administration period. In the aforementioned variations, the amount of neointimal thickening and/or other parameters may be measured at time points (e.g., every week, month, year) after cessation of the inhibitor administration. EXAMPLE 7 MTOR INHIBITOR, PDGF-R INHIBITOR AND TREATMENT OF ATHEROSCLEROSIS SUBJECTS The purpose of this example is to demonstrate the benefits of treating subjects, who have been diagnosed with atherosclerosis (or a predisposition for the disease) in helping to inhibit or prevent the progression of the disease. Subjects, so identified are divided into four groups. One group is given a straight placebo (e.g., as discussed in Example 5), one group is given a mTOR inhibitor, e.g. rapamycin, one group is given a PDGF-R inhibitor, e.g., imatinib mesylate, and one group is given both a mTOR inhibitor and a PDGF-R inhibitor (e.g., both rapamycin and imatinib mesylate). In addition or in the alternative, subjects maybe generally grouped by sex, weight, age, and medical history to help minimize variations among subjects. Dosages as discussed above in Example 1 or in the "Dosage" section may be employed. For example, PDGF-R inhibitor (e.g. imatinib mesylate) 6-10 mg/kg/d (approximately 400-600 mg/d per subject). For mTOR inhibitor (e.g. sirolimus, everolimus), the loading dose is 0.1 mg/kg (6mg/subject), reduced by 2mg/d until dose levels of 1-3 mg/d and blood maintenance trough levels of 12-20 ng/ml (chromatographic determinations) are eventually obtained. In some embodiments, dose levels 1-3 mg/d or less may suffice. The study may involve examinations at zero point, at six months, at one year, and optionally the subjects may be examined using any appropriate technique and criteria including without limitation intravascular ultrasound (e.g., power Doppler), angiograms, MRI, blood pressure, physicals and any other means of assessing the vascular health of the subject. Improvements may be evaluated using statistical analysis of the data, e.g., with ANONA t-tests or student t-tests. Significant improvement over any parameter used to assess treatment for atherosclerosis provides an indication that the combinatorial therapy of a mTOR inhibitor and PDGF-R inhibitor is beneficial. Testing for effectiveness may performed as described in Example 6. hi some embodiments, an atherosclerosis model is achieved by feeding baboons a high fat diet for at least three years (although other durations are also possible). The drag administration may begin before, after or during the high fat diet. However, any model of atherosclerosis maybe employed. One may also use an experimental set-up analogous to that described in Example 2. hi some variations, in order to show the long term efficacy (lasting effect) of the treatment, the inhibitor administration is ceased at a particular time point, and that time point may be varied amongst the subjects within a group or between different groups. To control for variables, administration of an experimental formulation may be replaced with a control formulation, or one control formulation with another, upon cessation of the initial administration period, hi the aforementioned variations, the amount of neointimal thickening and/or other parameters may be measured at time points (e.g., every week, month, year) after cessation of the inhibitor administration. EXAMPLE 8 ESTABLISHING DOSAGE REGIMEN FOR INHIBITOR OF MTOR AND INHIBITOR OF A PDGF-R IN STENT APPLICATIONS To test various dosage combinations of inhibitors when administered via coated-stents, mammalian subjects are given stents with varying concentrations of one or both inhibitors. In the case of primates, e.g., humans or baboons, neointimal hyperplasia is followed using various techniques including, but not limited to, angiograms, intravascular ultrasound, and without limitation those techniques described herein.

Check-ups using such techniques may be used at any time point, but in one variation, they are performed at least at sixth months and one year following implantation of the stents, and optionally at six month intervals thereafter. When the mammalian subjects are mice or rats, they may be sacrificed at suitable time points, e.g., six months and one year. In some embodiments the stent contains only a single inhibitor, e.g., rapamycin, and the other compound is administered orally, e.g., imatinib mesylate. See, e.g., Example 3 above, the other variation described in Example 3 may also be employed here in Example 8 where appropriate. EXAMPLE 9 DIABETIC VASCULOPATHY STUDIES An experimental set-up similar to that presented in Example 6, except that instead of transplant recipients, the mammalian subjects chosen have been diagnosed with diabetes. In those embodiments using humans subjects, individuals with either Type I or Type II diabetes or both types may participate. Appropriate animal models may also include Type I (insulin-dependent) and Type II (non-insulin dependent) diabetic subjects. Type I animal models are available through use of beta-islet cell destroying compounds including without limitation antibodies and small molecules, e.g., alloxan and streptozotocin. Any Type II model is also appropriate. See, e.g., Clark and Pierce, J Pharmacol Toxicol Methods, 43(1): 1-10 (2000). In addition to general vascular health and conditions as described in the other examples, particular attention is made to diabetic conditions, including without limitation diabetic angiopathies, e.g., diabetic microangiopathy, diabetic macroangiopathy, diabetic nephropathy, and diabetic retinopathy. Success of treatment may also be assessed as described in Example 6 and elsewhere herein. EXAMPLE 10 EX VIVO STUDIES WITH A RAT MODEL OF AORTIC ANGIOPLASTY This study was carried out to demonstrate the behavior of cells following angioplasty and how that behavior is influenced by the combination therapy described herein. Such behavior includes both the migration and proliferation of cells following angioplasty. Explant outgrowth, migration and proliferation of smooth muscle cell-like cells from aortic tissue were measured after PTCA injury, i.e., at the time point when the circulating precursors to intimal cells appear in the injured vessel wall. Three days prior to performing PTCA injury on the thoracic aorta, Wistar rats were started on one of the following regimens: the rats received PDGF-R inhibitor imanitib mesylate (lOmg/kg/d), mTOR inhibitor rapamycin (lmg/kg/d), both drags, or neither drug (control-saline). On day 2 after injury, the vessels were removed, chopped into 1 mm³ pieces using a McElwain tissue chopper, and the pieces were plated on 96 well microculture plates in regular culture medium as described in Aavik, et al., FASEB J, 16:724-726 (2002), incorporated by reference herein in its entirety. 3H-TdR incorporation was measured using scintillation 48 hours after pulse. The percent of wells showing outgrowth on days 1 and 2 ex vivo, cell migration (outgrowth), and the proliferation of migrating cells after 3H-TdR pulse labeling were quantitated and are depicted in FIGS. 9A-C (stars indicate p-values compared to drug non-treated controls using unpaired t-test). Both drags significantly inhibited outgrowth (sprouts) both on day 1 and on 2 of ex vivo culture (FIG. 9A). The combination therapy caused greater inhibition than either drag administered alone. Both drags also significantly inhibited migration distance of outgrowing cells as measured on day 2 of ex vivo culture (FIG. 9B). The combination therapy was again better at inhibition than either drug administered alone. As seen in FIG. 9C, both drugs significantly inhibited the cell replication as measured at day 2 of vivo culture. The mTOR inhibitor was better in inhibiting proliferation than was (at this dose level) the PDGF-R inhibitor. These data indicate that sirolimus appears to be both anti-proliferative and anti-migratory, whereas imatinib appears to be primarily anti-migrative. That the two target proteins, mTOR and PDGF-receptor, employ different signaling cascades helps explain the differences in action ex vivo as well as the synergistic effect observed after PTCA in vivo. These results reinforce the efficacy and utility of an mTOR inhibitor and PDGF-R inhibitor combination in controlling remodeling and neointimal hyperplasia, e.g., following injury from allograft and/or PTCA and inhibiting vessel cell growth in general. EXAMPLE 11 INTRAVASCULAR SURGERY IN BABOONS EXPOSES NON-OPERATED VESSELS TO CELL PROLIFERATION Endovascular surgery is used to conect localized defects in the arterial tree. These defects are usually a local manifestation of generalized disease, most commonly atherosclerosis. Proliferative vasculopathy leading to restenosis of the operated area is a well-known complication of intravascular operative intervention, such as endarterectomy. The following experiments demonstrate that, concomitantly with the restenotic process in the operated artery, proliferation in non-operated arteries is also induced. Vasculoprotective drag therapies (like the combination of a mTOR inhibitor and PDGF-R inhibitor presented herein) can be administered to protect against both of these complications concomitantly. PTCA of the left carotid and left iliac arteries was performed in baboons using techniques and procedures in accordance with those described in DuToit, et al., Ann. Med. 33:63-78 (2001) incorporated by reference herein in its entirety. The arteries of the baboons were labeled with 5-bromo-2-deoxyuridine (BrdU) three hours before sacrifice as described in DuToit, et al. Subjects were sacrificed at 0 (no PTCA performed), 0.01 (15 minutes), 2, 3, 4, 7, 14 and 28 days after PTCA. One subject was sacrificed at each time point, except for day 3 when two subjects were sacrificed. Specimens for histological sections were taken from two proximal (P) and two distal (D) segments of the injured carotid and inquinal (iliac) arteries and from the same segments in contralateral arteries, i.e., the right carotid and right iliac arteries. All specimens were fixed in paraformaldehyde, embedded in paraffin and stained for BrdU as described in Du Toit, 2001. There were no proliferating cells in any of the arteries of non-operated baboon vessels. Therefore, any level of proliferation seen in PTCA-treated animals was considered significant. Results are shown in FIGS. 10A-H. The micrographs (FIGS 10A, 10C, 10E, and 10G) show BrDU-incorporated cells with Mayer's counterstaining at an objective magnification of 100X (arrows indicate stained cells). A strong proliferative response was seen in the adventitia, media and (neo)intima of the injured left carotid and inquinal (iliac) arteries. The proliferation peaked on days 2-3 and subsided by day 7, the next time point measured. Interestingly, a strong proliferative response was also observed in the contralateral arteries. The proliferative response in the contralateral arteries corresponded timewise to the proliferation in the injured artery, and the magnitude of proliferation was approxomately 10% of that of the injured arteries. These results indicate that endovascular surgery leads to proliferation in non-injured vessels, and possibly exposes the subject to accelerated vascular disease.

Prophylactic vasculoprotective drag therapy, including the combination therapy described herein, can be administered before, during, and/or after endovascular intervention, not only to prevent restenosis in the operated area, but also to stop any acceleration of vascular disease in the rest of the arteries. Example 13 sets out how the procedures in the present example maybe modified to demonstrate the efficacy of such therapies. EXAMPLE 12 REJECTION OF AN ALLOGRAFT EXPOSES RECIPIENT VESSELS TO PROLIFERATION Accelerated recipient atherosclerosis is a frequent complication of organ allografts. According to registry data, approximately 50% of renal transplant recipients die with a functioning graft and close to 40% lose their transplant because of chronic allograft rejection. Of those who die with a functioning graft, approximately 40% die for cardiovascular reasons, followed by 20% for infection and 10% for malignancy. Core needle biopsy-controlled multicenter studies have indicated that cardiovascular death rate follows the progression of chronic rejection in the transplant (unpublished). Acute vascular rejection is an important risk factor for chronic rejection. This study was undertaken to determine whether acute rejection is associated with pathological abnormalities in the recipient vessels. Aortic allografts were exchanged between mixed lymphatic culture (MLC) incompatible male baboons. Anesthetic, pain control and post operative care were carried out in accordance with Du Toit, 2001. A midline laparotomy was performed on each baboon, followed by a left medial visceral rotation of the left colon and the small bowel, that exposed the infrarenal aorta below the left renal vein. The aorta, both common iliacal arteries, the median sacral (tail) artery and the inferior mesenteric artery were dissected and prepared for clamping. Intravenous heparin (100E/ kg) was administered, and after 3 minutes, the above-mentioned vessels were clamped, the inferior mesenteric and lumbar arteries were ligated, and this piece of aorta was simultaneously excised in each baboon. The grafts were swapped and immediately transplanted to the recipients with continuous 6-0 Prolene suture for proximal and distal anastomoses. The clamps were released, hemostasis assured and the hindgut, lower limbs and tail were assessed for ischemia. No complications occurred. The laparotomies were closed in standard fashion using 1 Nylon mass closure and 30 Nylon skin stitches. One subject was sacrificed on each of 0, 2, 3, 14, 28, 42, and 92 days following the allograft surgery. The animals were labeled with BrdU three hours before sacrifice. Upon sacrifice, the abdominal transplant (AA) and the thoracic aorta (TA) were retrieved via midline incision, excluding the suture lines, hi addition, 3 cm of the right (RCA) and left (LCA) carotid artery, 5 cm of the right (RIA) and left (LIA) iliac artery, and 2 cm long segments of the right (RCOR) and left (LCOR) coronaries were retrieved. All vessels were fixed in paraformaldehyde and the mid-portion of each vessel was processed for histology. The proliferating cells in the vessel wall were assessed after 3 hour BrdU pulse and by demonstration of Ki67 and PCNA antigens with immunohistochemistry with largely concordant results. Results are shown in FIGS. 11 A&B. (Unit area is 0.0625 mm²; note differences in the scale. The symbols for each vascular layer are indicated in the figure insert.) In aorta allografts, a strong biphasic proliferation pattern was observed. Within the first peak (day 3) the proliferating cells were found mostly in the adventitia and media but during the second peak (days 28-42) also in the neointima. In recipient vessels, proliferation coincided or followed the first proliferative peak in the allograft and was often nearly equal in intensity. Contrary to the transplant, replicating cells in the recipient vessels were mostly found in the media. Concomitantly, internal elastic laminae appeared fragmented, endothelial staining for FNIJJ antigen became weak and staining for alpha smooth muscle antigen increased. The intima size of the thoracic aorta and both iliac arteries tripled in size as a consequence of acute allograft rejection. The results obtained with this non-human primate model demonstrate that acute rejection of a (vascular) transplant is accompanied with a generalized proliferative response in recipient arteries and suggest that acute vascular rejection contributes to accelerated vascular disease in the recipient. The results further suggest that the immune and inflammatory response in the allograft is causative to the proliferation in the recipient vessels, and that acute (vascular) rejection is one causative factor in accelerated atherosclerosis of the transplant recipient. Vasculoprotective drag therapies (such as the combination mTOR inhibitor and PDGF-R inhibitor therapy described herein) can be applied during acute rejection to prevent accelerated fibrointimal vascular disease both in the allograft and in the graft recipient. Example 13 sets out how the procedures in the present example may be modified to carry out and study such therapies. EXAMPLE 13 VASCULOPROTECTIVE THERAPY STUDIES The studies described in Examples 11 and 12 are carried out using the combination drag therapy described herein. Administration of the drag therapy (or saline control) is begun two days before the procedure (PTCA in the case of Example 11, allograft surgery in the case of Example 12). The dosages may be varied from one study to another, e.g., suitable dosages are described above in the dosage section. The number of animals in a given group may also be varied. In one embodiment, there are 3 baboons or other primates per group. The dates of sacrifice may be as described in Examples 11 and 12 or may occur more or less frequently. The length of the study may also be varied. If a particular dose or combination of doses appears effective, the study may be repeated at a lower dosage of one or both inhibitors. For the PTCA study of Example 11, a successful drag treatment is characterized by a decrease in the number of BrdU-labeled cells relative to those in control. Such decreases in BrdU-labeled cells as well as Ki67 and PCNA positive cells relative to control would be indicative of successful treatment for the allograft study of Example 12. EXAMPLE 14 MTOR INHIBITOR, PDGF-R INHIBITOR AND TREATMENT OF DE NOVO STENOSIS AND RESTENOSIS FOLLOWING ANGIOPLASTY IN ARTERIO-VENOUS BRESCIA FISTULA The purpose of this example is to demonstrate how the propensity for de novo stenosis and restenosis of a AN- Brescia fistula (Brescia-Cimino Shunt) used for access in hemodialysis could be prevented, inhibited, or treated. Because of turbulence in such an AN fistula there is a high propensity for stenosis due to intimal hyperplasia in the arterialized venous vessel used for the connection between the two vessels. Following a stenosis the flow becomes reduced and the fistula cannot be used any longer for vascular access in hemodialysis. This situation is usually solved by angioplasty, in which a stent cannot be used, because vascular access is obtained by punching high-flow, wide needles into the fistula. The flow rate is of great importance in order to achieve high enough performance in the dialyzer. Angioplasty is often followed by restenosis in the fistula, calling for an additional session of angioplasty. Drugs have not previously been used for the prevention of de novo stenosis or for prevention of restenosis following angioplasty. 50%) of the procedures probably fail in 6 months because of restensosis. Brescia-Cimino fistula is performed by distal side-to-side anastomosis of radial artery to cephalic vein. If the distal vein is too small, a Teflon graft proximal to the wrist is used for a u-shaped anastomosis of the same vessels at the level of cubital fossa. Together with arterialized pressure the wall of the cephalic vein begins to resemble that of an artery, the lumen expands and the vessel is used as a puncture site in hemodialysis treatment. Within 1-2 years, stenosis develops in the vein, distal to the anastomosis site at the area of turbulent blood flow. The standard therapy is percutaneous transluminal angioplasty (PTA). The treatment is carried out in, e.g., 20, patients who have been subjected to angioplasty because of stenosis of the fistula. The study may comprise hemodialysis subjects with stenotic AN-fistula. Preferably, subjects include hemodialysis patients who have been on regular hemodialysis for at least three months with a stenotic AN-fistula who is undergoing PTA. Age of patients is 18 years for human subject studies. Patients exhibiting evidence of systemic infection and/or known hypersensitivity to sirolimus are generally excluded. Hemodialysis patients with stenotic AN-fistula are randomized prior to PTA in the following four treatment arms: (1) No medication; (2) mTOR inhibitor (Sirolimus) lmg/d for 3 months; (3) PDGFR inhibitor (imanitib) 10 mg/kg/d for 3 months; (4) mTOR inhibitor 1 mg/d and PDGFR inhibitor 10 mg/kg/d for 3 months. Medication will be started 2 days before PTA, and thereafter orally and daily for 3 months Study duration may be shortened to 1 month if results are seen earlier. Also dosage may be lowered if results favorable. In some experiments, an mTOR inhibitor and/or a PDGF-R inhibitor is administered during 4-6 weeks after the primary operation of the fistula or following angioplasty, i.e., until re-endothelialization has occurred. This study also provides guidance for dosing for other indications, including those described herein, where stenosis, restenosis, and/or arteriosclerosis is a concern and where monitoring is more difficult than in the context of dialysis. The treatment can be applied at the time point of precursor cell influx and their maturation to intima SMC-like cells; these precursors may be recent immigrants from bone marrow. The study includes flow measurements of the AN-fistula up to three times a week using transonic instrument. The restenosis propensity will be monitored by measuring the flow rate in the fistula, which can be assessed easily at every dialysis session, e.g., 2-3 times per week. Reduction by 50% of the reduced flow rate in the placebo group by the mTOR-PDGF-R inhibitor treatment is judged highly clinically effective. Pulmonary x-ray and laboratory data are taken to detect ongoing infections. Study duration and follow-up is suggested to be 3-6 months The primary end-point is flow measurement at each dialysis treatment.

Each patient can serve as the patient's own control with first post-PTA flow measurement as reference; consequently the number of patients to be randomized can be small. Alternatively, or in addition, controls may include age-matched subjects that have not received the therapy medications. The secondary end point is restenosis. The restenosis may be judged from measurements of blood flow in the fistula using a transonic instrument. Safety Endpoints may include pulmonary X-ray before starting and evaluation of safety data comparing the two groups, with special focus on infections. Power calculations: 50% of patients are expected to develop restenosis in the placebo arm within 6 mos. A clinically significant reduction of the degree of restenosis would be if it is reduced by 50%, i.e., a finding of no more than a 25% reduction in blood flow in the actively treated patients would be clinically highly significant. Power calculations in Uppsala show that with this layout only 3-4 patients are needed for each treatment arm. Considering 5 patients per arm, 20 patients would be needed to complete the study with a single dose medication level. This experiment allows one to follow the restenosing process using repeated flow measurements when the patients are given dialysis treatment. Blood flow in the fistula conesponds very well with the degree of stenosis in the fistula, and can thus be monitored up to 3 times a week, at each dialysis session, following the intervention. Each measurement takes only 5 minutes. As approximately 50% of patients are expected to develop significant restenosis within 6 months, a 6-month follow-up would be sufficient. Iterative measurements may be done during the follow up, which also would improve the precision in these assessments of re-appearance of restenosis. hi those terms an example maybe that from a flow of 500 ml/ min after procedure, a reduction to 250 ml/min would be considered to be an end-point. If the treatment leads to a reduction by only <125 ml/min, this would be considered as a clinically highly significant and important effect. The precision in the measurements of flow with this instrument is considered to be, without any correction for variation in cardiac output, 7-8% (coefficient of variation). The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Because modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof. The patents, patent application publications and other publications (e.g., Journal articles) referenced herein are incorporated in their entirety. Although the applicant(s) invented the full scope of the claims appended hereto, the claims are not intended to encompass within their scope the prior art work of others. Therefore, in the event that statutory prior art within the scope of a claim is brought to the attention of the applicants by a Patent Office or other entity or individual, the applicant(s) reserve the right to exercise amendment rights under applicable patent laws to redefine the subject matter of such a claim to specifically exclude such statutory prior art or obvious variations of statutory prior art from the scope of such a claim. Variations of the invention defined by such amended claims also are intended as aspects of the invention.

Claims

CLAIMS What is claimed is: 1. A composition comprising an inhibitor of mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R).

2. Use of an inhibitor of mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R), in combination, in the manufacture of a medicament for prophylactic treatment of neointimal hyperplasia in mammals.

3. The composition or use of claim 1 or 2, further comprising a pharmaceutically acceptable diluent, adjuvant, excipient, or carrier.

4. The composition or use of any one of claims 1 -3 , wherein the inhibitors are present in the composition in amounts effective to achieve a synergistic inhibition of neointimal hyperplasia in a mammalian subject.

5. The composition or use of any one of claims 1 -4, wherein the inhibitor of mTOR comprises a member selected from the group consisting of rapamycin, everolimus, CCI-779, tumstatin, ABT578, AP23573, and AP22594.

6. The composition of any one of claims 1 -4, wherein the inhibitor of mTOR is a compound of formula:

wherein Ri is CH₃ or C -6alkynyl, R₂is H, -CH₂-CH₂-OH, 3-hydroxy-2-(hydroxymethyl)- -2-methyl- propanoyl or tetrazolyl, and X is =0, (H,H) or (H,OH) provided that R₂ is other than H when X is =O and Ri is CH₃, or a prodrug thereof when R is -CH₂-CH₂-OH, e.g. a physiologically hydrolysable ether thereof.

7. The composition of any one of claims 1-4, wherein the inhibitor of mTOR comprises rapamycin.

8. The composition of any one of claims 1 -7, wherein the inhibitor of the PDGF-R comprises a compound of the formula:

wherein the N-phenyl-2-pyrimidine-amine compound of formula B is a compound wherein Ri is 4-pyrazinyl, 1 -methyl- IH-pyrrolyl, amino- or amino-lower alkyl-substituted phenyi wherein the amino group in each case is free, alkylated or acylated, lH-indolyl or lH-imidazolyl bonded at a five-membered ring carbon atom, or unsubstituted or lower alkyl-substituted pyridyl bonded at a ring carbon atom and unsubstituted or substituted at the nitrogen atom by oxygen; wherein R₂ and R₃ are each independently of the other hydrogen or lower alkyl, one or two of the radicals R , R₅, R_δ, R₇ and R₈ are each nitro, fluoro-substituted lower alkoxy or a radical of formula: -N(R₉)-C(=X)-(Y)_n -R₁₀ wherein R₉ is hydrogen or lower alkyl, X is oxo, thio, imino, N-lower alkyl-imino, hydroximino or O-lower alkyl-hydroximino, Y is oxygen or the group NH, n is 0 or 1 and R₁₀ is an aliphatic radical having at least 5 carbon atoms, or an aromatic, aromatic-aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, heterocyclic or hetero- cyclicaliphatic radical, and the remaining radicals R₄, R₅, RQ, R₇ and R₈ are each independently of the others hydrogen, lower alkyl that is unsubstituted or substituted by free or alkylated amino, piperazinyl, piperidinyl, pyrrolidinyl or by morpholinyl, or lower alkanoyl, trifluoromethyl, free, etherified or esterifed hydroxy, free, alkylated or acylated amino or free or esterified carboxy, or a salt of such a compound having at least one salt- forming group.

9. The composition of any one of claims 1 -7, wherein the inhibitor of the PDGF-R comprises imatinib mesylate.

10. A composition according to any one of claims 1-9, further comprising a somatostatin receptor 1,4 selective agonist.

11. A composition according to claim 10, wherein the selective agonist comprises a compound selected from the group consisting of SS-14, L-363,377, L-797,591, L-779,976, L-795,778, L-803,087, L-817,818, and combinations thereof.

12. A composition according to any one of claims 1-9, further comprising an estrogen-receptor beta selective agonist.

13. A composition according to claim 12, wherein the estrogen- receptor beta selective agonist is selected from the group consisting of 17beta-estradiol, genistein, and combinations thereof.

14. A method of inhibiting neointimal hyperplasia in a mammalian subject, comprising: administering to a mammalian subject in need of treatment to inhibit or prevent neointimal hyperplasia, an inhibitor of mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R) in amounts effective to inhibit neointimal hyperplasia.

15. The method of claim 14, wherein the inhibitors are administered in amounts effective to achieve a synergistic inhibition or prevention of neointimal hyperplasia in the mammalian subject.

16. The method of claim 14 or 15, wherein the inhibitor of mTOR is administered locally using a stent and the PDGF-R inhibitor is administered orally.

17. The method of claim 14 or 15, wherein the inhibitor of the PDGF- R is administered locally using a stent and the inhibitor of mTOR is administered orally.

18. The method of claim 14 or 15, wherein the inhibitor of the PDGF- R and the inhibitor of mTOR are administered systemically.

19. The method of any one of claims 14-18, wherein the mammalian subject is in need of treatment to inhibit or prevent atherosclerosis.

20. The method of any one of claims 14-18, wherein the method further comprises the step of selecting a mammalian subject in need of treatment to inhibit or prevent neointimal hyperplasia.

21. The method of claim 20, comprising selecting a mammalian subject that is an allograft, autograft, or xenograft transplant recipient, and wherein the inhibitors are administered in amounts effective to inhibit at least one disease or condition selected from the group consisting of accelerated atherosclerosis, chronic allograft rejection, transplant arteriosclerosis, and allograft arteriosclerosis.

22. The method of claim 21 , wherein the mammalian subj ect has undergone an allograft or xenograft transplant of an organ or tissue.

23. The method according to claim 22, further comprising administering to the mammalian subject an immunosuppressant that is not an mTOR inhibitor.

24. The method of claim 21 , wherein the mammalian subj ect has received an autograft of a tissue or vessel.

25. The method of claim 21, wherein the mammalian subject has received or will receive an arteriovenous graft.

26. The method of any one of claims 21-25, wherein administration is begun prior to the transplant surgery.

27. The method of claim 26, wherein administration is begun at least two days prior to the transplant surgery.

28. The method according to any one of claims 21-27, further comprising monitoring the mammalian subject for accelerated atherosclerosis, chronic allograft rejection, transplant arteriosclerosis, and allograft arteriosclerosis.

29. The method of claim 20, comprising selecting a mammalian subject that is an angioplasty patient in need of treatment to inhibit or prevent restenosis of a blood vessel endothelial denudation.

30. The method of claim 29, wherein the mammalian subject has undergone a percutaneous transluminal angioplasty (PTA).

31. The method of claim 29, wherein the mammalian subj ect has undergone a percutaneous transluminal coronary angioplasty (PTCA).

32. The method of any one of claims 29-31 , wherein the angioplasty included implantation of a stent.

33. The method of claim 32, wherein at least one of the inhibitors is administered as a coating on the stent.

34. The method of any one of claims 29-32, wherein at least one of the inhibitors is administered orally.

35. The method of any one of claims 29-34, wherein administration is begun prior to the angioplasty.

36. The method of claim 32, wherein the inhibitor of mTOR and inhibitor of the PDGF-R are administered as coatings on the stent.

37. The method of claim 20, comprising selecting a mammalian subject that is is a diabetic subject in need of treatment to inhibit or prevent diabetic angiopathy.

38. The method of claim 37, wherein the diabetic angiopathy is selected from the group consisting of diabetic microangiopathy, diabetic macroangiopathy, diabetic nephropathy, and diabetic retinopathy.

39. The method of claim 20, comprising selecting a mammalian subject that has been diagnosed with an autoimmune disorder.

40. The method of claim 20, wherein the mammalian subject is selected because of need for hemodialysis.

41. The method of claim 20 or 40, wherein the mammalian subject is selected because the subject has, or will receive, an arteriovenous fistula (ANF) for vascular access.

42. The method of claim 41 , wherein the ANF is a Brescia-Cimino fistula.

43. The method of claim 41 , wherein the ANF links a radial artery to a cephalic vein.

44. The method of claim 41 , wherein the administering begins before the primary operation of the fistula.

45. The method of any one of claims 41-44, wherein the administering is performed for 2-10 weeks following primary operation of the fistula.

46. The method of any one of claims 41 -44, wherein the administering is performed for 4-6 weeks following primary operation of the fistula.

47. The method of claim 41 , wherein the administering begins before angioplasty to treat stenosis of the fistula.

48. The method of claim 41 or 47, wherein the administering is performed for 2-10 weeks following angioplasty of the fistula.

49. The method of claim 41 or 47, wherein the administering is performed for 4-6 weeks following angioplasty of the fistula.

50. The method of any one of claims 14-49, wherein the inhibitor of mTOR comprises a member selected from the group consisting of rapamycin, everolimus, CCI-779, tumstatin, ABT578, AP23573, and AP22594.

51. The method of any one of claims 14-49, wherein the inhibitor of mTOR is a compound of formula :

wherein Ri is CH₃ or C₃-6alkynyl, R₂ is H, -CH₂-CH₂-OH, 3-hydroxy-2-(hydroxymethyl)- -2-methyl- propanoyl or tetrazolyl, and X is =O, (H,H) or (H,OH) provided that R₂ is other than H when X is =O and Ri is CH , or a prodrag thereof when R₂ is -CH₂-CH -OH, e.g. a physiologically hydrolysable ether thereof.

52. The method of any one of claims 14-49, wherein the inhibitor of mTOR comprises rapamycin.

53. The method of any one of claims 14-52, wherein the inhibitor of the PDGF-R comprises a compound of the formula:

wherein the N-phenyl-2-pyrimidine-amine compound of formula B is a compound wherein Ri is 4-pyrazinyl, 1 -methyl- lH-pymolyl, amino- or amino-lower alkyl-substituted phenyi wherein the amino group in each case is free, alkylated or acylated, lH-indolyl or lH-imidazolyl bonded at a five-membered ring carbon atom, or unsubstituted or lower alkyl-substituted pyridyl bonded at a ring carbon atom and unsubstituted or substituted at the nitrogen atom by oxygen; wherein R₂ and R₃ are each independently of the other hydrogen or lower alkyl, one or two of the radicals R_t, R₅, R_ό, R and R₈ are each nitro, fluoro-substituted lower alkoxy or a radical of formula: -N(R₉)-C(=X)-(Y)_n -Rio wherein R₉ is hydrogen or lower alkyl, X is oxo, thio, imino, N-lower alkyl-imino, hydroximino or O-lower alkyl-hydroximino, Y is oxygen or the group NH, n is 0 or 1 and Rio is an aliphatic radical having at least 5 carbon atoms, or an aromatic, aromatic-aliphatic, cycloaliphatic, cycloaliphatic-aliphatic, heterocyclic or hetero- cyclicaliphatic radical, and the remaining radicals R_t, R₅, R₆, R₇ and R₈ are each independently of the others hydrogen, lower alkyl that is unsubstituted or substituted by free or alkylated amino, piperazinyl, piperidinyl, pyrrolidinyl or by morpholinyl, or lower alkanoyl, trifluoromethyl, free, etherified or esterifed hydroxy, free, alkylated or acylated amino or free or esterified carboxy, or a salt of such a compound having at least one salt- forming group.

54. The method of any one of claims 14-53, wherein the inhibitor of the PDGF-R comprises imatinib mesylate.

55. The method of any one of claims 12-49, wherein the inhibitor of mTOR comprises rapamycin and the inhibitor of the PDGF-R comprises imatinib meslyate.

56. The method according to any one of claims 14-55, further comprising a somatostatin receptor 1,4 selective agonist.

57. The method according to any one of claims 14-55, further comprising an estrogen-receptor beta selective agonist.

58. The method of any one of claims 14-15, 18-32, and 37-57, wherein the inhibitors are administered orally.

59. The method of any one of claims 14-15, 19-33, and 35-57, wherein the inhibitors are administered proximate to a location susceptible to or characterized by neointimal hyperplasia.

60. The method of any one of claims 14-15, 19-24, 28-31, and 37-57, wherein the inhibitors are administered via an endovascular stent, an extravascular collar, or a catheter.

61. The method of any one of claims 14-15, 19-24, 28-31, and 37-57, wherein the inhibitors are administered by impregnating or coating a medical device with at least one of the inhibitors and introducing the medical device into the mammalian subject.

62. The method of claim 61 , wherein the medical device is a stent.

63. The method of any one of claims 14-62, wherein the mTOR inhibitor is administered with the PDGF-R inhibitor at a ratio of 1 mg of mTOR inhibitor to 10 mg of PDGF-R inhibitor.

64. The method of any one of claims 14-32, 34-35, and 37-57, wherein the inhibitors are administered daily for at least about 13 days.

65. The method of any one of claims 14-32, 34-35 and 37-57, wherein the inhibitors are administered daily for at least about 1 year.

66. The method of any one of 14-32, 34-35 and 37-57, wherein the inhibitors are administered daily.

67. The method of any one of 14-32, 34-35 and 37-57, wherein the mTOR inhibitor is provided in a range of about 1-3 mg/day and the PDGF-R inhibitor is provided in a range of about 400-600 mg/day.

68. A medical device comprising a surface or chamber for delivery of a therapeutic agent to a mammalian subject, wherein the device comprises an inhibitor of mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Ractor Receptor (PDGF-R) on the surface or in the chamber, and wherein the inhibitors are provided in amounts effective to inhibit neointimal hyperplasia in a mammalian subject. -

69. A medical device according to claim 68 comprising an endovascular stent designed to contact a surface of a blood vessel in the course of surgery to treat stenosis of the blood vessel, the stent comprising a surface for contacting a surface of a blood vessel, and a composition on said stent surface, said composition comprising an inhibitor of mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet- Derived Growth Ractor Receptor (PDGF-R), wherein the inhibitors are provided in amounts effective to inhibit neointimal hyperplasia.

70. A medical device according to claim 68 comprising an extravascular collar designed to contact a surface of a blood vessel in the course of surgery to treat stenosis of the blood vessel, the collar comprising a wall shaped to surround the outer surface of a blood vessel, wherein the wall encloses a space containing an inhibitor of mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet- Derived Growth Factor Receptor (PDGF-R), wherein the inhibitors are provided in amounts effective to inhibit neointimal hyperplasia.

71. A medical device according to claim 68 comprising a catheter having a surface for contacting a surface of a blood vessel, and a composition on said catheter surface, said composition comprising an inhibitor of mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet-Derived Growth Factor Receptor

(PDGF-R), wherein the inhibitors are provided in amounts effective to inhibit neointimal hyperplasia.

72. A medical device according to claim 68 comprising a balloon catheter having a void for holding a therapeutic agent for delivery to the interior of a blood vessel, and a composition contained in the void, the composition comprising an inhibitor of mammalian Target of Rapamycin (mTOR) and an inhibitor of a Platelet- Derived Growth Factor Receptor (PDGF-R), wherein the inhibitors are provided in amounts effective to inhibit neointimal hyperplasia.

73. The medical device of any one of claims 68-72, wherein the amounts are effective to synergistically inhibit neointimal hyperplasia in a mammalian subject.

74. A unit dose comprising an inhibitor of mammalian Target of

Rapamycin (mTOR) packaged with an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R), wherein the inhibitors are included in the unit dose in amounts effective to inhibit neointimal hyperplasia when co-administered; wherein the inhibitors are packaged together for co-administration to a human subject, but are not in admixture.

75. The unit dose of claim 74, wherein the inhibitor of mTOR comprises rapamycin and the inhibitor of the PDGF-R comprises imatinib meslyate.

76. The unit dose of claim 74 or 75, wherein the amounts are effective to synergistically inhibit neointimal hyperplasia in a mammalian subject.

77. hi a composition comprising an inhibitor of mammalian Target of Rapamycin (mTOR), the improvement comprising the addition of an inhibitor of a Platelet-Derived Growth Factor Receptor (PDGF-R) in the composition, wherein the inhibitors are present in amounts effective to synergistically inhibit or prevent neointimal hyperplasia in a mammalian subject.

78. The composition of claim 77, wherein the inhibitor of mTOR comprises rapamycin and the inhibitor of the PDGF-R comprises imatinib mesylate.