Title of Invention

DEVICES, METHODS, AND COMPOSITIONS TO PREVENT RESTENOSIS .

Abstract The present invention discloses a medical device configured to deliver a composition comprising a polymer and a first and second drug to a blood vessel to reduce the degree or substantially prevent the occurrence of restenosis in the blood vessel, said first drug being epothilone D and said second drug being rapamycin or a rapamycin analog, wherein said first and second drugs show synergistic activity.
Full Text DEVICES, METHODS, AND COMPOSITIONS TO PREVENT RESTENOSIS
Background of the Invention
Atherosclerosis is the formation of a hardened plaque comprising cholesterol, fatty
acids, cellular wastes, and calcium along the walls of medium and large arteries. Such
plaques can cause a narrowing ("stenosis") of a blood vessel, such as a medium or
large artery, and is a leading cause of heart attack and stroke. Typically,
atherosclerosis is treated using balloon angioplasty (also called Percutaneous
Transluminal Coronary Angioplasty or "PTCA") in which a catheter is inserted in a
major artery of the patient and is guided to a major artery of the heart. A balloon
located in the distal end of the catheter is inflated to push the plaque against the wall
of the constricted vessel, thus widening the vessel and improving blood flow. More
recently, small metallic spring-like devices called stents can be inserted at the point of
construction to provide a supporting framework that maintains the shape of the vessel.
Unfortunately, these procedures do not always provide permanent solutions. In about
40% of all PTCA procedures and about 25% of stentings, the stenosis recurs within
about six months of the procedure. Such recurrence is called "restenosis", and, in the
case of restenosis following stent insertion ("in-stent restenosis"). In-stent restenosis
occurs when scar tissue grows under the layer of otherwise healthy vessel tissue that
grows over the framework of the stent and provides improved blood flow through the
stent to a degree sufficient to restrict blood flow through the stented segment of the
vessel.
Recently, specially coated drug-eluting stents that include a cytotoxic agent have been
provided to reduce the occurrence of in-stent restenosis. A variety of drugs have been
used in such stents, including sirolimus (rapamycin), which inhibits growth of smooth
muscle cells ("SMCs"), paclitaxel, an antiproliferative agent, and several anti-
inflammatory drugs. See, for example: Ozaki et al., (1996), "New stent technologies,"
Prog. Cardiovasc. Disease 39(2): 129-40; Lincoff et al., (1997) "Sustained local
delivery of dexamethasone by a novel intravasculancluting stent to prevent restenosis
in the porcine coronary injury model." Journal of the American College of Cardiology
29(4): 808-816; Violaris et al. (1997) "Endovascular stents: a 'break through
technology', future challenges." Int J Card Imaging 13(1): 3-13; Garas et al. (2001)
"Overview of therapies for prevention of restenosis after coronary interventions."
Pharmacology & Therapeutics 92(2-3): 165-178; Garas et al. (2001) "Overview of
therapies for prevention of restenosis after coronary interventions." Pharmacol Ther
92(2-3): 165-78; Regar et al. (2001) "Stent development and local drug delivery." Br
Med Bull 59: 227-48; Chieffo & Colombo (2002) "Drug-eluting stents." Minerva
Cardioangiol 50(5): 419-29; Greenberg & Cohen (2002) "Examining the economic
impact of restenosis: implications for the cost-effectiveness of an antiproliferative
stent." Z Kardiol 91 Suppl 3: 137-43; Grube & Bullesfeld (2002) "Initial experience
with paclitaxel-coated stents." J Interv Cardiol 15(6): 471-5; Grube et al. (2002)
"Drug eluting stents: initial experiences." Z Kardiol 91 Suppl 3:44-8; Hehrlein et al.
(2002) "Drug-eluting stent: the "magic bullet" for prevention of restenosis?" Basic
Res Cardiol 97(6): 417-23; Liistro et al. (2002) "First clinical experience with a
paclitaxel derivate—eluting polymer stent system implantation for in-stent restenosis:
immediate and long-term clinical and angiographic outcome." Circulation 105(16):
1883-6; Muller et al. (2002) "[State of treatment of coronary artery disease by drug
releasing stents]." Herz 27(6): 508-13; Peters (2002) "Can angiotensin receptor
antagonists prevent restenosis after stent placement?" American Journal of
Cardiovascular Drugs 2(3): 143-148; Prebitero and Asioli (2002) "[Drug-eluting
stents do they make the difference?]." Minerva Cardioangiol 50(5): 431-42; Sheiban
et al. (2002) "Drug-eluting stent: the emerging technique for the prevention of
restenosis." Minerva Cardioangiol 50(5): 443-53; Fattori & Piva (2003) "Drug-
eluting stents in vascular intervention." Lancet 361(9353): 247-9. In particular, U.S.
Patent No. 6,231,600 to Zhong describes a hybrid stent coating including a
non-thrombogenic agent and paclitaxel-containing polymer that allows time-release
of the paclitaxel to reduce or prevent in-stent restenosis. U.S Patent application
20030207856 discloses stents coated with the Hsp90 inhibitor geldanamycin.
Nevertheless, it would be advantageous to provide additional drug-eluting stents
having different restenosis-preventing or reducing agents. For example, paclitaxel has
such great cytotoxicity that necrosis of the vessel wall has been observed. Thus,
paclitaxel has relatively narrow therapeutic window that can complicate formulation
and administration.
SUMMARY OF THE INVENTION
The present invention addresses these needs by providing compositions, methods, and
devices that substantially reduce or prevent restenosis. We have unexpectedly found
that certain geldanamycin analogs, particularly the 17-amino-17-desmethoxy-
geldanamycins such as 17-allylamino-17-desmethoxygeldanamycin (17-AAG) and
17-(dimethylaminoethyl)-17-desmethoxygeldanamycin (DMAG), display selective
cytotoxicity against smooth muscle cells and hence provide unique advantages for use
in controlling restenosis. Further, we have discovered that particular combinations of
cytotoxic drags are unexpectedly synergistic, thus reducing the concentrations of the
individual cytotoxic drugs needed to prevent restenosis.
In one aspect, the present invention includes a medical device configured to deliver
one or more drugs described herein to a blood vessel to reduce the degree or
substantially prevent the occurrence of restenosis in the blood vessel. In one
embodiment, the drug is an epothilone. In another embodiment, the drug is a
geldanamycin derivative. In still another embodiment, the drug is a rapamycin analog.
In a more particular embodiment, the drug is a desoxyepothilone, and, more
particularly, epothilone D. In another embodiment, the drug is
17-allylamino-17-desmethoxygeldanamycin, 17-[2-(dimethylamino)ethylamino]-
17-desmethoxy geldanamycin, or 17-[2-(dimethylamino)ethylamino]-17-desmethoxy-
11-O-methylgeldanamycin. In yet another embodiment, the drug is
17-azetidinyl-17-desmethoxy-geldanamycin. In some embodiments, the above-
described drugs are used in combination to provide a synergistic effect. In some
embodiments, the drug or drugs described herein is further combined with an anti-
inflammatory. In some embodiments, the device is a stent. In other embodiments, the
device is a polymer wrapper or device used to cover vascular anastomoses. In some
embodiments, the device includes at least one coating effective to deliver one or more
drugs described herein to a blood vessel.
In another aspect, the present invention provides compositions to reduce the degree or
substantially prevent the occurrence of restenosis in the blood vessel. In one
embodiment, the drug is an epothilone. In another embodiment, the drug is
geldanamycin or a geldanamycin derivative. In still another embodiment, the drug is a
rapamycin analog. In a more particular embodiment, the drug is a desoxyepothilone,
and, more particularly, epothilone D. In another embodiment, the drug is
17-allylamino-l7-desmethoxygeldanamycin, 17-[2-(dimethylamino)ethylamino]-
17-desmethoxy-geldanamycin, or 17-[2-(dimethylamino)ethylamino]- 17-desmethoxy-
11-O-methylgeldanamycin. In yet another embodiment, the drug is 17-azetidinyl-
17-desmethoxy geldanamycin. In some embodiments, the drug or drugs described
herein is further combined with an anti-inflammatory agent. The composition can
include a polymer such that the drug of the invention elutes from the polymer into
blood vessel tissues proximal to the polymer
In still another aspect, the present invention provides methods to to reduce the degree
or substantially prevent the occurrence of restenosis in the blood vessel. In one
embodiment, the method of the invention includes delivering a drug described herein
to a blood vessel requiring treatment for, or prevention of, restenosis, in an amount
sufficient to substantially reduce, or substantially prevent, restenosis in such blood
vessel. In one embodiment, the drug is an epothilone. In another embodiment, the
drug is geldanamycin or a geldanamycin derivative. In still another embodiment, the
drug is a rapamycin analog. In a more particular embodiment, the drug is a
desoxyepothilone, and, more particularly, epothilone D. In another embodiment, the
drug is 17-allylamino-17-desmethoxygeldanamycin, 17-[2-(dimethylamino)-
ethylamino]-17-desmethoxygeldanamycin, or 17-[2-(dimethylamino)ethylamino]-
17-desmethoxy-11-O-methylgeldanamycin. In yet another embodiment, the drug is
17-azetidinyl-17-desmethoxygeldanamycin. In some embodiments, the drug or drugs
described herein is further combined with an anti-inflammatory agent.
These and other aspects and advantages will become apparent when the Description
below is read in conjunction with the accompanying Drawings.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
Figure 1A and Figure IB are plots of cell viability for smooth muscle cells ("SMC",
Figure 1 A) and human umbilical vein endothelial cells ("HUVEC", Figure 1B)
exposed to 17-allylaminogeldanamycin ("17-AAG") as measured by optical density
using the methods described in Example 1 herein. The SMC and HUVEC were
exposed to a control (?) and to 17-AAG at concentrations of 10 nanomolar ("nM",*),
100 nM (A), and 1,000 nM (x).
Figure 2A and Figure 2B are plots of cell viability for smooth muscle cells ("SMC"
Figure 2A) and human umbilical vein endothelial cells ("HUVEC", Figure 2B)
exposed to 17-[(2-dimethylamino)ethylamino]geldanamycin ("17-DMAG") as
measured by optical density using the methods described herein. The SMC and
HUVEC were exposed to a control (?) and to 17-DMAG at concentrations of
10 nanomolar ("nM",¡), 100 nM (A), and 1,000 nM (x).
Figure 3 A and Figure 3B are plots of cell viability for smooth muscle cells ("SMC",
Figure 3 A) and human umbilical vein endothelial cells ("HUVEC", Figure 3B)
exposed to KOS-862 (epothilone D) as measured by optical density using the methods
described herein. The SMC and HUVEC were exposed to a control (?) and to
epothilone D at concentrations of 10 nanomolar ("nM",B), 100 nM (A), and 1,000 nM
(x).
Figure 4 is a plot of the Combination Index for the combination of rapamycin and
17-AAG in SMC, which indicates synergistic effect.
Figure 5 is a plot of the Combination Index for the combination of rapamycin and
KOS-862 in SMC, which indicates synergistic effect.
Figure 6 A and Figure 6B are plots demonstrating the synergistic effect of combining
17-AAG with rapamycin. Figure 6A shows the change in viability of DLD-1 cells as
measured by optical density ("OD") for rapamycin (solid line), 17-AAG (squares),
and their combination (diamonds) at concentrations of 0 to 120 nM. Figure 6B shows
the Combination Index for the combination of rapamycin and 17-AAG, which
indicates synergistic effect.
Figure 7A and Figure 7B are plots demonstrating the synergistic effect of combining
KOS-862 (epothilone D) with rapamycin. Figure 7A shows the change in viability of DLD-1 cells as
measured by optical density ("OD") for rapamycin (solid line), KOS-862 (epothilone
D) (squares), and their combination (diamonds) at concentrations of 0 to 120 nM.
Figure 7B shows the Combination Index for the combination of rapamycin and
KOS-862, which indicates synergistic effect.
Figure 8 shows release kinetics for epothilone D ("KOS-862") from various
polymer matrices. Epothilone D is released from poly(lactide) at a rate of
approximately 6 micrograms/day and from polyurethane at 1.58 micrograms/day.
DETAILED DESCRIPTION OF THE INVENTION
In one embodiment, the present invention provides stents including a coating that
releases a drug selected from the group of epothilones and geldanamycins. Suitable
epothilones for combination in the present invention can be any epothilone, and, more
particularly, any epothilone having useful therapeutic properties; see, for example,
Hoefle et al. (1993) Ger. Offen. DE 4138042; Nicolaou et al. (1998) PCT Publication
WO 98/25929; Reichenbach et al. (1998) PCT Publication WO 98/22461;
Danishefsky et al. (1999) PCT Publication WO 99/01124; Hoefle et al. (1999) PCT
PublicationWO 99/65913; Nicolaou et al. (1999) PCT PublicationWO 99/67253;
Nicolaou (1999) PCT Publication WO 99/67252; Vite et al. (1999) PCT Publication
WO 99/54330; Vite et al. (1999) PCT Publication WO 99/02514; Vite et al. (1999)
PCT Publication WO 99/54319; Hoefle et al. (2000) Ger. Offen. DE 19907588;
Hoefle et al. (2000) PCT Publication WO 00/50423; Danishefsky et al. (2001) U.S.
Patent 6,204,388; Danishefsky et al. (2001) PCT Publication WO 01/64650; Santi et
al. (2001) PCT Publication WO 01/92255; Avery (2002) PCT Publication WO
02/30356; Danishefsky et al. (2002) U.S. Pat. Appl. Publ. 20020058286; Nicolaou et
al. (2002) U.S. Patent 6,441,186; Nicolaou et al. (2002) U.S. Patent 6,380,394:
Wessjohan & Scheid (2002) Ger. Offen. DE 10051136; and White et al. (2002) U.S.
Pat. Appl. Publ. 20020062030. Such epothilones can be obtained using any
combination of total chemical synthesis, partial chemical synthesis, or
chemobiosynthesis methods and materials known to those of skill in organic
chemistry, medicinal chemistry, and biotechnology arts. Specific examples of
epothilones having useful therapeutic properties include, but are not limited to,
epothilone A, epothilone B, epothilone C, epothilone D, 4-desmethylepothilone D,
azaepothilone B (epothilone B lactam), 21-aminoepothilone B,
9, 10-dehydroepothilone D, 9, lO-dehydro-26-trifluoroepothilone D,
11-hydroxyepothilone D, 19-oxazolylepothilone D, 10,11-dehydroepothilone D,
19-oxazolyl-10,11-dehydroepothilone D, and trans-9,10-dehydroepothilone D.
In another embodiment, the drug is geldanamycin or an analog or derivative thereof.
In one embodiment, the drug is geldanamycin. In preferred embodiments, the drug is
an analog of geldanamycin, for example a 17-(substituted amino)-17-
desmethoxygeldanamycin. In one preferred embodiment, the drug is
17-allylamino-17-desmethoxygeldanamycin ("17-AAG"). In still another
embodiment, the drug is 17-[2-(dimethylamino)ethylamino]-17-desmethoxy-
geldanamycin ("17-DMAG"). In another embodiment, the drug is
17-[2-(dimethylamino)ethylamino]-17-desmethoxy-11-O-methylgeldanamycin. In yet
another embodiment, the drug is 17-azetidinyl-17-desmethoxygeldanamycin. These
compounds can be obtained using methods known to those having skill in the organic
and medicinal chemistry arts; see, for example, Sasaki et al. (1981) U.S. Patent
4,261,989; Schnur et al. (1999) U.S. Patent 5,932,566; Zhang et al. (2003) PCT
Publication WO 03/026571; Santi et al. (2003) PCT Publication WO 03/13430, as
well as in co-pending U.S. Patent Applications Serial Nos.: 60/389,225; 60/393,929;
60/395,275; 60/415,326; and 60/420,820.
While geldanamycin itself is a potent cytotoxin, with IC50 values for smooth muscle
cells of approximately 0.9 nM, such high cytotoxicity may be problematic for the
treatment of restenosis where the localized drug concentrations can be high. For
effective treatment of restenosis, a drug showing selective cytotoxicity against smooth
muscle cells over endothelial cells, for example, would allow treatment of restenosis
with minimal damage to other cell types not involved in restenosis. We have
unexpectedly found that certain geldanamycin analogs, particularly the 17-amino~17-
desmethoxy-geldanamycins such as 17-allylamino-17-desmethoxygeldanamycin (17-
AAG) and 17-(dimethylaminoethyl)-17-desmethoxygeldanamycin (DMAG), display
selective cytotoxicity against smooth muscle cells (see Figures 1 and 2). While these
analogs are generally less cytotoxic than geldanamycin itself, 17-AAG for example
shows an IC50 of about 10 nM against smooth muscle cells, they show substantially
higher IC50 values against endothelial cells. Thus, these analogs offer unexpected
advantages over geldanamycin itself in the treatment of restenosis.
In another embodiment of the invention, the drug is rapamycin or a rapamycin analog.
By "rapamycin or a rapamycin analog" is meant a compound of structure (I),
wherein R1 is hydroxy, alkoxy, hydroxyethoxy, aryloxy, or heteroaryl; R2 is H or
OMe; R3 is H or Me; and R4 is H, OH, or OMe. Specific examples of rapamycin
analogs are described in PCT Publication WO 01/38416.
In preferred embodiments, rapamycin or a rapamycin analog is administered in
combination with a second drug to provide a synergistic cytotoxic effect on smooth
muscle cells. Examples of synergistic combinations include rapamycin with a
geldanamycin analog, as illustrated for rapamycin and 17-AAG in Figure 4, and
rapamycin with epothilone D, as demonstrated in Figure 5. The use of synergistic
mixtures is highly advantageous, as it allows use of lower drug loadings and/or
increased effectiveness at preventing restenosis. The ratios of the two drugs may be
determined by methods known in the art, for example as described below in Example
2.
In some embodiments, the drug or drug combination is combined with a stent so that
the process of restenosis is substantially mitigated or prevented. Such stents may be
metallic or made of a bioresorbable polymer. Examples of stents suitable with the
present invention include, but are not limited to, stents configured to elute a drug as
are known to those of skill in the cardiovascular medicine and medical device arts.
See, for example, Aggarwal et al. (1996) "Antithrombotic potential of
polymer-coated stents eluting platelet glycoprotein IIb/IIIa receptor antibody."
Circulation 94(12): 3311-3317; Ozaki et al. (1996), "New stent technologies," Prog.
Cardiovasc. Disease 39(2): 129-40; Lincoff et al. (1997) "Sustained local delivery of
dexamethasone by a novel intravascular eluting stent to prevent restenosis in the
porcine coronary injury model." Journal of the American College of Cardiology
29(4): 808-816; Violaris et al. (1997) "Endovascular stents: a 'break through
technology', future challenges." Int J Card Imaging 13(1): 3-13; Garas et al. (2001)
"Overview of therapies for prevention of restenosis after coronary interventions."
Pharmacology & Therapeutics 92(2-3): 165-178; Garas et al. (2001) "Overview of
therapies for prevention of restenosis after coronary interventions." Pharmacol Ther
92(2-3): 165-78; Regar et al. (2001) "Stent development and local drug delivery." Br
Med Bull 59:227-48; Chieffo & Colombo (2002) "Drug-eluting stents." Minerva
Cardioangiol 50(5): 419-29; Greenberg & Cohen (2002) "Examining the economic
impact of restenosis: implications for the cost-effectiveness of an antiproliferative
stent." Z Kardiol 91 Suppl 3: 137-43; Grube & Bullesfeld (2002) "Initial experience
with paclitaxel-coated stents." J Interv Cardiol 15(6): 471-5; Grube et al. (2002)
"Drug eluting stents: initial experiences." Z Kardiol 91 Suppl 3: 44-8; Hehrlein et al.
(2002) "Drug-eluting stent: the "magic bullet" for prevention of restenosis?" Basic
Res Cardiol 97(6): 417-23; Liistro et al. (2002) "First clinical experience with a
paclitaxel derivate-eluting polymer stent system implantation for in-stent restenosis:
immediate and long-term clinical and angiographic outcome." Circulation 105(16):
1883-6; Muller et al. (2002) "[State of treatment of coronary artery disease by drug
releasing stents]." Herz 27(6): 508-13; Peters (2002) "Can angiotensin receptor
antagonists prevent restenosis after stent placement?" American Journal of
Cardiovascular Drugs 2(3): 143-148; Prebitero and Asioli (2002) "[Drug-eluting
stents do they make the difference?]." Minerva Cardioangiol 50(5): 431-42; Sheiban
et al. (2002) "Drug-eluting stent: the emerging technique for the prevention of
restenosis." Minerva Cardioangiol 50(5): 443-53; Fattori & Piva (2003) "Drug-
eluting stents in vascular intervention." Lancet 361(9353): 247-9; Klugherz et al.
(2000) "Gene delivery from a DNA controlled-release stent in porcine coronary
arteries." Nature Biotechnology 18(11): 1181-1184; Carlyle et al. (2002) Eur. Pat.
Appl. Ep 1236478; Farb et al. (2002) "Oral Everolim Inhibits In-Stent Neointimal
Growth." Circulation 106(18): 2379-2384; Morice et al. (2002) "A randomized
comparison of a sirolim-eluting stent with a standard stent for coronary
revascularization." New England Journal of Medicine 346(23): 1773-1780; Moses et
al. (2002) "Perspectives of drug-eluting stents. The next revolution." American
Journal of Cardiovascular Drugs 2(3): 163-172; Shah et al. (2002) "Background
Incidence of Late Malapposition After Bare-Metal Stent Implantation." Circulation
106(14): 1753-1755; Swanson et al. (2002) "Human internal mammary artery organ
culture model of coronary stenting: a novel investigation of smooth mole cell
response to drug-eluting stents." Clinical Science 103(4): 347-353; Virmani et al.
(2002) "Mechanism of Late In-Stent Restenosis After Implantation of a Paclitaxel
Derivate-Eluting Polymer Stent System in Humans." Circulation 106(21):
2649-2651; and Yoon et al. (2002) "Local delivery of nitric oxide from an eluting
stent to inhibit neointimal thickening in a porcine coronary injury model." Yonsei
Medical Journal 43(2): 242-251.
In other embodiments, the stent is coated with one or more polymer substances to
facilitate blood flow over the stent surfaces and to provide a reservoir of the drug such
that the drug is released to provide substantial mitigation or prevention of restenosis.
Examples of such polymer are known to those of skill in the cardiovascular medicine
and medical device arts; see, for example, Levy et al. (1994) "Strategies for treating
arterial restenosis using polymeric controlled release implants." Biotechnol. Bioact.
Polym., [Proc. Am. Chem. Soc. Symp.]: 259-68; De Scheerder et al. (1995)
"Biocompatibility of polymer-coated oversized metallic stents implanted in normal
porcine coronary arteries." Atherosclerosis (Shannon, Ireland) 114(1): 105-14; Peng
et al. (1996) "Role of polymers in improving the results of stenting in coronary
arteries." Biomaterials 17(7): 685-94; Tartaglia et al. (1996) Can. Pat. Appl. Ca
2164684; Herdeg et al. (1998) "Antiproliferative stent coatings: Taxol and related
compounds." Semin Interv Cardiol 3(3-4): 197-9; Reich et al. (1998) PCT
Publication WO 98/08884; Santos et al. (1998) "Local administration of L-703081
using a composite polymeric stent reduces platelet deposition in canine coronary
arteries." American Journal of Cardiology 82(5): 673-675; Whitbourne (1998) PCT
Publication WO 98/32474; Tsuji et al. (2003) "Biodegradable stents as a platform to
drug loading," Int J Cardiovasc Intervent. 5(l):13-6; Lahann et al. (1999)
"Improvement of hemocompatibility of metallic stents by polymer coating." Journal
of Materials Science: Materials in Medicine 10(7): 443-448; Piro et al. (1999) "An
electrochemical method for entrapment of oligonucleotides into a polymer-coated
electrode." Proceedings of the International Symposium on Controlled Release of
Bioactive Materials 26th: 1176-1177; Bar et al. (2000) "New biocompatible polymer
surface coating for stents results in a low neointimal response." Journal of Biomedical
Materials Research 52(1): 193-198; Le More et al. (2000) Fr. Demande FR 2785812;
Verweire et al. (2000) "Evaluation of fluorinated polymers as coronary stent coating."
Journal of Materials Science: Materials in Medicine 11(4): 207-212; Zhong (2001)
U.S. patent 6,231,600; Heublein et al. (2002) Polymerized degradable hyaluronan—a
platform for stent coating with inherent inhibitory effects on neointimal formation in a
porcine coronary model." Int J Artif Organs 25(12): 1166-73; Lewis et al. (2002)
"Analysis of a phosphorylcholine-based polymer coating on a coronary stent pre- and
post-implantation." Biomaterials 23(7): 1697-1706; Roorda et al. (2002) PCT
PublicationWO 02/94335; and Rosenblum et al. (2003) PCT PublicationWO
03/07785.
In preferred embodiments, the polymer is selected from the group consisting of
poly(ester-amides) ("PEA"), polylactides ("PLA"), and amino acid-based
polyurethanes ("PU"). Suitable poly (ester-amides) are described in Lee et al. (2002)
"In-vivo biocompatibility evaluation of stents coated with a new biodegradable
elastomeric and functional polymer," Coron Artery Dis. 2002 Jun;13(4):237-41; and
U.S. Patent 6,703,040, which is incorporated herein by reference, and are prepared by
synthesizing monomers of two alpha amino acids with diols and diacids. In preferred
embodiments, the poly(ester-amide) is prepared from L-leucine, L-lysine, hexanediol,
and sebacic acid. The drugs can be chemically deposited into the polymer matrix or
conjugated onto the polymer backbone via the carboxyl groups of the L-lysine. The
polymer is elastomeric and can be crosslinked in situ using photo activators, resulting
in a strong yet biocompatible and reabsorbable polymer. The polylactide-based
polymers can be made from L-lactide, caprolactone, and polyethylene glycol
monomers in varying ratios. The polyurethane polymers can be made by condensing
monomers of alpha amino acids, such as L-leucine and L-lysine, with a diol. The
carboxyl groups of lateral L-lysine on the polymer can be used as an attachment site
for coupling drugs. The polyurethane polymers generally show a faster degradation
rate than the poly(ester-amide) polymers, and are generally similar in terms of
biocompatibility and reabsorbability.
When used for coating medical devices, for example stents, solutions of the polymer
and drug in volatile solvents, either individually or in combination, may be applied to
the surface by spraying or by dipping. The volatile solvents are then allowed to
evaporate, resulting in a coating on the device comprising the polymer and the drug.
Varying proportions of polymer and drug may be applied, depending upon the
potency of the drug and the time period over which the drug is to be released from the
medical device. To further control the rate of release of the drug, a topcoat of
additional polymer may be applied to the coated device. The medical devices may
subsequently be rendered aseptic, for example by gamma irradiation.
In another embodiment, the drug or drugs described herein can be used with a medical
device to prevent restenosis after vascular anastomosis, for example by being
combined with a polymer sheath or wrapping around the vessel wall. Such materials
are available commercially from Secant Medical, LLC of Perkasie, Pennsylvania,
USA. Further examples of suitable devices that may be coated with the compositions
of the invention may be found, for example in U.S. Patent 6,371,965. These devices
may be useful particularly after vascular anastomosis such as occurs during coronary
artery bypass graft surgery.
In other embodiments, one or more anti-inflammatory drugs effective to reduce or
prevent inflammatory processes from occurring in the vessel wall is included with the
drug or drugs described herein above. Examples of suitable anti-inflammatory drugs
include, but are not limited to, rapamycin and rapamycin analogs described in
WO 01/38416.
In other embodiments, one or more of the drugs described above are deposited
directly to the site of restenosis. Deposition can be accomplished using, e.g., a
catheter or suitable drug delivery device.
EXAMPLES
The following Examples are provided to illustrate certain aspects of the present
invention and to aid those of skill in the art in the art in practicing the invention.
These Examples are in no way to be considered to limit the scope of the invention in
any manner.
EXAMPLE 1
Demonstration that Compounds of the Invention Prevent or Reduce Processes
Associated with Restenosis
Compounds of the invention demonstrate activities consistent with the prevention or
reduction of cellular mechanisms associated with restenosis, as shown hereinbelow.
Thus, the compounds, methods, and devices of the invention will be recognized by
those of skill in the cardiovascular medicine arts as being effective to substantially
prevent or reduce restenosis.
The effects of varying drug concentrations of paclitaxel, rapamycin, and a drug
selected from the group consisting of epothilone D, 17-AAG, and 17-DMAG on
growth characteristics for the same human smooth muscle cells ("SMCs" and
endothelial cells ("ECs") were compared under in-vitro experimental conditions as
described hereinbelow.
Human aortic smooth muscle cells ("AoSMCs") and human umbilical vein
endothelial cells ("HUVECs") were plated on 96-well culture plates at a density of
about 10,000 cells per square centimeter (10,000 cells/cm2). The density was
determined using growth curves determined by calculating the average absolute
optical densities ("ODs", defined as cellular OD - media only OD) for each plating
concentration, for each day, and each cell type (AoSMC or HUVEC) over a five-day
time period. The AoSMCs were purchased frozen from
Clonetics/Biowhittaker/Cambrex (Item # CC-2571 / Lot # 0F0222 ). The AoSMCs
had company-determined culture characteristics on arrival: a total cell number of
917,500; cell viability: 95%; and a doubling time of between about twenty-four and
forty-eight hours. Pooled HUVECs were also purchased in frozen aliquot from
Clonetics/Biowhittaker/Cambrex (Item # CC-2519 / Lot # 1F0832). The
company-determined culture characteristics on arrival were: a total Cell number of
560,000; cell viability of 83%; and a doubling time of between about eighteen and
about forty-eight hours.
Prior to experiments, the AoSMCs and HUVECS were thawed and independently
propagated through two- or three population doublings following Clonetics
recommendations and standard cell culture techniques. Clonetics Growth Media and
Reagents were used without alteration in all aspects of the study described herein
unless otherwise noted. The details of the media and reagents can be found at the
Cambrex World-Wide Web site. SMGM contained: 500 ml SMBM-2 basal media,
5% FBS, and all recommended singlequot growth supplements (provided with
SMGM-2 bulletkit) ECGM contained: 500 ml EBM basal media, 2% FBS, and all
recommended singlequot growth supplements (provided with EGM-bulletkit).
After initial plating all 96-well plates were placed in a standard 37°C, 5% CO2
incubator. Conditions, including media, were not changed except as detailed below.
For consecutive 24-hour time-periods, from Day 1 to Day 5, a single 96-well plate
was removed from the incubator. For this plate, culture media was removed from all
wells and replaced with 100 microliters ("µl") of MTS reagent/media solution (see
below) and the plate was then placed back in the incubator 3-4 hours later this plate
was removed from the incubator and optical density data for each well was obtained
using a 96-well ELISA reader.
Cell Preparation Source cells were selected at 70-80 % confluency of the second or
third population doubling since initial thaw. In order to synchronize cell cycle, source
cells were changed from standard growth media to media containing 1% serum
twenty-four hours prior to experiment (other growth factors were unchanged). On
Day 0 of the experiment, source cells were removed from culture dishes by
trypsinization (0.05 x 1 min.-2 min), quantified by hemacytometer after centrifuge
(800 RPM x 5 min.), and re-suspended in media to obtain a stock solution of about
25,000 cells/ml.
The drugs were dissolved in dimethylsulfoxide ("DMSO") solvent to make stock
solutions, which were then diluted serially in media to three study concentrations
(10 nM; 100 nM; and 1,000 nM). The drugs at three concentration each, solvent
without drug at three concentrations, and standard media were added independently to
cells on the first day of the study only. Cells in two columns (16 wells) for each cell
type on each day will not receive drug and serve as internal controls. Cellular viability
and proliferation was assessed using the MTS assay for each cell type at each of the
six time points. Rapamycin was purchased from Sigma Aldrich as a 1 mg powder
(Item # R0395). Paclitaxel was purchased from Sigma Aldrich as a 5 mg powder
(Item # T7191). Epothilone D, 17-AAG, and 17-DMAG were obtained using the
methods and materials described above.
On Day 1, six hours after initial plating, the media was removed from all wells by
vacuum suction; and with the appropriate growth media-drug solution for each of
three drugs at three concentrations described above was added to the wells. For each
cell type (AoSMC or HUVEC), and on each day, two 96-well plates were required to
incorporate all three drugs (24 total plates). Standard wells contained only media and
were used for optical density ("OD") control in each individual plate during analysis.
Control wells contained the plate specific cells without drug or solvent, and served as
the control for all drug effects on a given day for a given cell type.
For consecutive 24 hour time-periods, from Day 0 to Day 5, four 96-well plates were
removed from the incubator (two plates each for AoSMCs and HUVECs). For these
plates, the culture media was removed from all wells and replaced with 100 µl of
MTS reagent solution, which contained 20 µl of Promega CellTiter 96 Aqueous One
reagent in 80 µl of cell appropriate growth media for each well. Promega
recommendations for assay use were followed throughout including reagent
administration under dark lighting 3-4 hours later these plates were removed from the
incubator and optical density data for each well or each plate was obtained using a 96-
well automated ELISA reader. Plates were read within 1.5 hrs of the same time each
day. Additional details for the CellTiter 96 Aqueous One Assay are available online at
the Promega World-Wide Web site.
Optical Densities for each column were averaged (n = 8). Using the MTS assay steps
detailed above, the "standard" wells contained only MTS reagent in media at the time
of analysis. The average OD values for these "standard" columns were then
subtracted from those column averages of drug treated cells, in order to obtain an
absolute OD for drug treated cells. The average OD values for the "standard"
columns were also subtracted from those columns containing control cells in order to
obtain an absolute OD for control cells.
Average absolute OD s for cells at a given drug concentration were plotted for Days
0-5 for both AoSMCs and HUVECs. Average absolute OD s for AoSMC and
HUVEC control cells were plotted on the same respective graphs for Days 0-5.
The results of the study are shown in Figures 1 and 2. From the figures, those of skill
in the pharmacology and medicine arts will understand that epothilone D, 17-AAG,
and 17-DMAG each shows dose-response characteristics consistent with utility to
reduce or prevent restenosis. Moreover, those of such skill will also understand from
the data presented that 17-AAG, and 17-DMAG each shows relative selectivity for
SMCs over ECs. Thus, the present invention also provides treatment methods and
compositions that are relatively selective for SMCs over ECs.
EXAMPLE 2
Demonstration of Synergistic Effects With Anti-Inflammatory Compounds
Human aortic smooth muscle cells were obtained from Cambrex (Walkersville, MD).
The cells were maintained in SmGM-2 growth medium (Cambrex). Rapamycin, 17-
AAG, and KOS-862 were obtained as described above or from commercial sources.
The compounds were dissolved in dimethylsulfoxide ("DMSO") to a concentration of
10 mM and stored at -20°C.
The cells were seeded in duplicate, in opaque-walled 96-well microtiter plates at a
cell density of 3,000 cells per well and allowed to attach overnight. Serial dilutions of
each drug were added, and the cells were incubated for 96 hours. The IC50 values for
the drugs was determined using the CellTiter-Glo Luminescent Cell Viability Assay
(Promega, Madison, WI), which correlates with the number of live cells.
For the drug combination assays, the cells were seeded in duplicate in 96-well plates
(3,000 cells/well). After an overnight incubation, the cells were treated with drug
alone or a combination of the drug and rapamycin. Based on the IC50 values of each
individual drug, combined drug treatments were designed to provide constant ratios of
the two drugs being tested for synergistic effect, i.e., at a concentration equivalent to
the ratio of their individual IC50 values. Three different treatment schedules were
used: The cells were treated with rapamycin and 17-AAG; or rapamycin and KOS-
862 simultaneously for 96 hours. Cell viability was determined by luminescent assay
(Promega). Combination analysis was performed by using Calcusyn software
(Biosoft, Cambridge, UK).
Each of the combinations of rapamycin and 17-AAG and rapamycin and KOS-862
was found to be synergistic as shown in Figures 4 and 5. Thus, each of these two
combinations is likely to have better pharmacological effect in preventing or treating
restenosis than the effect of either component alone. Synergy was also demonstrated
using the procedure described above in DLD-1 cells (Figures 6 and 7).
EXAMPLE 3
In Vitro Drug Elution of 17-AAG Matrixed PEA
The elution of 17-AAG from representative poly (ester-amide) coated stainless
steel disks was determined by UV and HPLC methods. Stainless steel disks (0.71
cm") were coated with polymer and 17-AAG by pipetting solutions of PEA-24-Bz
and 17-AAG in absolute ethanol onto the disks and air drying overnight. In some
cases, the coated disks were further topcoated with either PEA-24 or PEA-17, and
then dried using the same techniques. Total drug loads of 50, 100, or 200
micrograms/cm2 were used, with a drug load of either 10 or 20% (w/w) versus
polymer. For elution, the disks were placed in a 15 mL plastic vial containing 1.5 mL
of medium consisting of either chymotrypsin (0.4 mg/mL), phosphate buffered saline
(PBS), fetal bovine serum (FBS), or human serum. The vials were incubated at 37 °C,
and the medium was sampled daily. Drug release was assayed by HPLC analysis of
an aliquot pretreated by solid-phase extraction (see Example 4), or by the UV
absorbance of the aliquot (200 µL), extrapolated from a calibration curve made from
drug standards. The UV assay gave results consistent with 96% of theoretical. The
HPLC method entailed chromatography using a 250x4.6 mm 5 micron 100 A Zorbax
Eclipse XDB C8 reversed-phase column with a 12.5 x 4.6 mm matching guard
column. The mobile phases were A: 0.2% acetic acid in water, and B: 0.1% acetic
acid in acetonitrile, flow rate 1 mL/min. A gradient elution was performed: 50%B for
2 minutes, then 9 minutes to 95% B, then isocratic at 95% B for 5 min, then back to
50% for 1 min and equilibrate for 4 min. 17-AAG was detected by UV at 330 nm.
The release data for 17-AAG into chymotrypsin medium demonstrated that
17-A AG is released at a sustained rate at least up to day 5, at which time the
experiment terminated. Non-topcoated matrix released 17-AAG at a faster rate than
topcoated matrix, with 56% total drug released over 5 days compared with 40% for
the non-topcoated matrix.
The release data for 17-AAG into FBS medium demonstrated that 17-AAG is
is released at a sustained rate at least up to day 4.5, at which time the experiment
terminated. Non-topcoated matrix released 17-AAG at a faster rate than topcoated
matrix, with 31% total drug released over 4.5 days compared with 21% for the non-
topcoated matrix.
The effect of increased topcoating was studied using human serum medium.
With a drug loading of 200 micrograms/cm2, a 200 microgram topcoat gave 16%
release of 17-AAG after 24 hours in human serum, whereas both a 400 microgram
and a 600 microgram topcoate gave 6-7% release. Thus, doubling the topcoat has a
significant effect on 17-AAG release, wheras tripling the topcoat has no further effect.
The solubility of 17-AAG in PBS is 60 micrograms/mL, and the IC50 for
endothelial cells is 350 nM. These studies suggest a drug loading of at least 200
micrograms of 17-AAG per stent with a 20-30% (w/w) drug/polymer formulation.
EXAMPLE 4
Solid-Phase Extraction of Drugs from Serum
Drug aliquots from serum experiments were subjected to solid-phase
extraction by loaded onto the top of 3 mL Isolute HM-N solid phase extraction
columns (Argonaut; San Carlos, California). After 5-10 minutes, the columns were
eluted with 10-12 mL of chloroformdsopropanol (95/5 v/v) followed by 4 mL of ethyl
acetate/isopropanol (95/5 v/v). The total eluate was concentrated, and the residues
reconstituted and filtered through an 0.5 micron filter prior to HPLC analysis.
Recovery of 17-AAG from the solid phase extraction was 88.7%. Recovery of
epothilone D was 95-98%.
EXAMPLE 5
Release Kinetics of 17-AAG from Coated Stents in Porcine Serum
Unmounted Metronic 'Driver' 18 x 3.5 mm stents were coated with
MVPEA/17-AAG matrixed polymer material by spray coating. Three groups of
stents were used in this study: (i) a low-dose group with 10% (w/w) drug load; these
had 450 micrograms of polymer, 50 micrograms of 17-AAG, and 250 micrograms of
topcoat; (ii) a high-dose group with 30% (w/w) drug load; mese had 150 micrograms
of polymer, 150 micrograms of 17-AAG, and 250 micrograms of topcoat; and (iii) a
control group coated with polymer only (700 micrograms). Coated stents were
sterilized by gamma irradiation.
Three stents from each group were placed aseptically into sterile glass vials
and treated with 5 mL of sterile porcine serum at 37 °C with gentle agitation by
shaking at 120 rpm. All 5 mL of serum was removed from each vial under sterile
conditions at 0.5,2,4,6,12, and 24 hours, and then 2, 3,5,7, and 10 days. Fresh
serum was added to the vials and incubation was continued after each time point. The
time point aliquots were subjected to solid-phase extraction (see Example 4) prior to
analysis by HPLC.
These studies demonstrated that 17-AAG was released into porcine serum
along with an apparent metabolite.
EXAMPLE 6
Release Kinetics of 17-AAG in Human Serum
Stainless steel disks (0.71 cm2) coated on one side with PEA-17-AAG having
a drug loading of 100 ug/cm2 (equal to 71 micrograms total 17-AAG) with either no
topcoat or 210 ug, 420 ug, or 640 ug of a PEA topcoate (same as basecoat) were
exposed to either human serum or chymotrypsin solution and 17-AAG was measured
as described in Example 3. Results are given in Table 1.
Table 1. Release kinetics of 17-AAG in human serum. Percent of loaded drug found
in serum as a function of the amount of topcoat polymer over a 14-day period.
A disk coated with the PEA polymer exposed to chymotrypsin (0.4 mg/mL)
showed increasing weight loss due to degradation of the polymer, with the PEA
degradation by about 14% over 5 days and about 30% over 14 days. After 5 days in
chymotrypsin solution, a drug-loaded disk released about 55%, indicating that drug
release represents the combined effects of drug diffusion and matrix erosion.
The advantages and qualities of the invention will be apparent from the foregoing
discussion. The present invention provides useful methods, compositions, devices,
and drugs for reducing or preventing restenosis. Moreover, the invention provides
useful methods, compositions, devices, and drugs for reducing or preventing
restenosis that are selective for smooth muscle cells over endothelial cells. Thus, the
present invention will be appreciated by those of skill in the pharmacology and
medicine arts to provide treatments and prophylactics for restenosis that have reduced
undesirable side effects compared to current restenosis treatment methodologies
described herein. Furthermore, those of skill in the pharmacology, medicine, and
medical device arts will understand that many alternative embodiments of the
invention not explicitly described herein are nevertheless encompassed by the present
invention. Examples of such alternative embodiments include, but are not limited to,
particular combinations of polymers for drug delivery, particular stents, and particular
methods of drug delivery.
WE CLAIM;
1. A medical device configured to deliver a first and second drug to a blood
vessel to reduce the degree or substantially prevent the occurrence of
restenosis in the blood vessel, said first drug being epothilone D and said
second drug being rapamycin or a rapamycin analog, wherein said first and
second drugs show synergistic activity.
2. The medical device as claimed in claim 1 wherein the medical device is a stent
or polymer wrapper.
3. A composition comprising a polymer and a first and second drug, said first
drug being epothilone D and said second drug being rapamycin or a
rapamycin analog, wherein said first and second drugs show synergistic
activity.
4. The composition as claimed in claim 3 wherein the polymer is selected from
the group consisting of a polylactide, a photo-curable poly(ester-amide), and a
polyurethane.
5. A composition as claimed in claim 3 for reducing the degree or substantially
preventing restenosis in a blood vessel.
The present invention discloses a medical device configured to deliver a
composition comprising a polymer and a first and second drug to a blood vessel to
reduce the degree or substantially prevent the occurrence of restenosis in the blood
vessel, said first drug being epothilone D and said second drug being rapamycin or a
rapamycin analog, wherein said first and second drugs show synergistic activity.

Documents:

1931-kolnp-2005-granted-abstract.pdf

1931-kolnp-2005-granted-assignment.pdf

1931-kolnp-2005-granted-claims.pdf

1931-kolnp-2005-granted-correspondence.pdf

1931-kolnp-2005-granted-description (complete).pdf

1931-kolnp-2005-granted-drawings.pdf

1931-kolnp-2005-granted-examination report.pdf

1931-kolnp-2005-granted-form 1.pdf

1931-kolnp-2005-granted-form 13.pdf

1931-kolnp-2005-granted-form 18.pdf

1931-kolnp-2005-granted-form 3.pdf

1931-kolnp-2005-granted-form 5.pdf

1931-kolnp-2005-granted-gpa.pdf

1931-kolnp-2005-granted-reply to examination report.pdf

1931-kolnp-2005-granted-specification.pdf


Patent Number 233869
Indian Patent Application Number 1931/KOLNP/2005
PG Journal Number 16/2009
Publication Date 17-Apr-2009
Grant Date 16-Apr-2009
Date of Filing 28-Sep-2005
Name of Patentee KOSAN BIOSCIENCES, INC.
Applicant Address 3832 BAY CENTER PLACE, HAYWARD, CA
Inventors:
# Inventor's Name Inventor's Address
1 JOHNSON ROBERT JR., G. 3656 HAPPY VALLEY ROAD, LAFAYETTE, CA 94549
PCT International Classification Number A61F 2/00
PCT International Application Number PCT/US2004/010212
PCT International Filing date 2004-03-29
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 60/490,098 2003-07-24 U.S.A.
2 60/458,521 2003-03-28 U.S.A.