Patent Application
20050282849
The present invention relates to methods and compounds for inhibiting angiogenesis. More particularly, the present invention relates to methods and compounds for treating solid tumor cancers.
Aberrant angiogenesis plays a critical role in the pathogenesis of numerous diseases, including malignant, ischemic, inflammatory and immune disorders (Carmeliet, Nat. Med., 9(6):653-60 (2003), Ferrara, Semin. Oncol., 29(6 Suppl 16):10-4 (2002)). The best-known of these disorders are cancer, exudative macular degeneration and diabetic retinopathy (DR), the last two of which are leading cause of blindness in the United States (Witmer et al., Prog. Retin Eye Res., 22(1):1-29 (2003), Clark et al., Nat. Rev. Drug Discovery, 2:448-459 (2003)). During the last decade our understanding of the molecular basis of angiogenesis has grown considerably. Numerous cytokines and growth factors that stimulate angiogenesis, such as VEGF, FGF-2, PDGF, IGF-1, TGF, TNF-α, G-CSF have been identified (Ferrara et al., Nat. Med., 5(12):1359-64 (1999), Kerbel et al., Nat. Rev. Cancer, 2(10):727-39 (2002), Rofstad et al., Cancer Res., 60(17):4932-8 (2000)). Among these growth factors, Vascular Endothelial Growth Factor (VEGF) plays a central role in angiogenesis (Ferrara, Semin. Oncol., 29(6 Suppl 16):10-4 (2002)).
VEGF, also known as VEGF-A, was initially identified for its ability to induce vascular permeability and to promote vascular endothelial cell proliferation (Leung et al., Science, 246:1306-1309 (1989), Plouet et al., EMBO J, 8:3801-3806 (1989), Connolly et al., J. Biol. Chem., 264:20017-20024 (1989)). VEGF is encoded by a single gene that gives rise to four isoforms by alternative splicing (Tischer et al., J. Biol. Chem., 266:11947-11954 (1991)). All four isoforms share the same unusually long and GC rich 5′-UTR, as well as a 3′-UTR that includes multiple RNA stability determinants. The receptors VEGFR-2 (also known as KDR or Flk-1) and VEGFR-1 (previously known as Flt1) recognize the dimeric form of VEGF (Ortega et al., Front. Biosci., 4:D141-52 (1999), Sato et al., Annals of New York Academy of Science, 902:201-207, (2000)). The highly specific VEGFR-2 receptor is expressed on endothelial cells. VEGF binding to the VEGFR-2 receptor activates the receptor's tyrosine kinase activity, leading to endothelial cell proliferation, differentiation and primitive vessel formation (Shalaby et al., Nature, 376:62-66, (1995)). VEGFR-1 inhibits endothelial cell growth either by acting as a decoy or by suppressing signaling pathways through VEGFR-2 (Fong et al., Nature, 376:66-70 (1995)).
Over 30 years ago, it was proposed that inhibition of tumor angiogenesis could be an effective approach for the treatment of cancer (Folkman, N. Engl. J. Med., 285(21):1182-6 (1971)). VEGF and its receptor have been demonstrated to have a central role in tumor angiogenesis, especially in the early stages of tumor growth (Hanahan et al., Cell, 86:353-364, 1996)). Indeed, increased levels of VEGF expression have been correlated with microvessel density in primary tumor tissues (Gasparini et al., J. Natl. Cancer Inst., 89:139-147 (1997)). Moreover, increased levels of the VEGF transcript are found in virtually all of the common solid tumors (Ferrara et al., Endocr. Rev., 18:4-25, 1997)). In general, tumor-bearing patients have higher levels of VEGF compared to those in tumor-free individuals, and high VEGF levels in serum/plasma are associated with poor prognosis (Dirix et al., Br. J. Cancer, 76:238-243 (1997)). Consistent with the role of VEGF in tumor angiogenesis, VEGF null embryonic stem cells showed a dramatically reduced ability to form tumors in nude mice (Carmeliet et al., Nature, 380:435-439 (1996)). Direct evidence for the involvement of VEGF in tumorgenesis was demonstrated by using specific antibodies against VEGF in human xenografts implanted in nude mice (Kim et al., Nature, 362:841-844 (1993), Hichlin et al., Drug Discovery Today, 6:517-528 (2001)). In these studies, the inhibition of tumor growth correlated positively with decreased vessel formation in the antibody-treated tumors. Subsequent experiments using the soluble receptors substantiated the importance of VEGF activity in tumor growth (Lin et al., Cell Growth Differ., 9(1):49-58 (1998)), and demonstrated that inactivation of VEGF by specific antibody treatment directly resulted in a nearly complete suppression of tumor-associated neovascularization (Borgstrom et al., Prostate, 35:1-10 (1998), Yuan et al. Proc. Natl. Acad. Sci. USA, 93:14765-14770 (1996)).
In exudative macular degeneration and diabetic retinopathy, pre-clinical experiments and clinical trials have demonstrated that over production of VEGF is critical for aberrant retinal or choroidal neovascularization (reviewed in Witmer et al., Prog. Retin Eye Res., 22(1):1-29 (2003)). Evidence has been obtained that intra-ocular VEGF levels are strongly correlated with active retinal/choroidal neovascularization (CNV) in patients with diseases such as diabetic retinopathy and wet form macular degeneration (Funatsu et al., Am. J. Ophthalmol., 133(4):537-43 (2002), Lip et al., Ophthalmology, 108(4):705-10 (2001)). In addition, studies using transgenic mice demonstrated that overexpression of VEGF in retinal pigment epithelial cells or photoreceptor cells results in choroidal or retinal neovasucularization (Schwesinger et al., Am. J. Pathol., 158(3):1161-72 (2001), Ohno-Matsui et al., Am. J. Pathol., 160(2):711-9 (2002)). In recent studies neutralizing antibodies, soluble receptor, receptor antagonists, or siRNA have proven efficacious in reducing VEGF-mediated blood vessel formation in animal models and in the clinic. (Eyetech Study Group, 22(2):143-52 (2002), Krzystolik et al., Arch. Ophthalmol., 120(3):338-46 (2002), Shen et al., Lab Invest., 82(2):167-82 (2002), Honda et al., Gene Ther., 7(11):978-85 (2000), Saishin et al., J Cell Physiol., 195(2):241-8 (2003)).
VEGF expression is regulated by a number of factors and agents including cytokines, growth factors, steroid hormones and chemicals, and mutations that modulate the activity of oncogenes such as ras or the tumor suppressor gene VHL (Maxwell et al., Nature, 399:271-275 (1999), Rak et al., Cancer Res., 60:490-498 (2000)). Nevertheless, hypoxia is the most significant physiologic signal for regulating VEGF expression. Hypoxia results in enhanced VEGF expression by increasing both the transcription rate and stability of the VEGF transcript (Ikeda et al., J. Biol. Chem. 270:19761-19766 (1995), Stein et al., Mol. Cell. Biol. 18:3112-3119 (1998), Levy et al., J. Biol. Chem. 271:2746-2753 (1996)). Hypoxia-inducible factor lax (HIF-1α) is a transcription factor that increases VEGF gene expression in cells undergoing hypoxia by binding to the hypoxia response element (HRE) located in the VEGF promoter (Liu et al., Circ. Res., 77:638-643 (1995), Semenza, Annu. Rev. Cell. Dev. Biol., 5:551-578 (1999)). Both the stability and translation efficiency of the VEGF transcript is influenced by sequences in the 5′- and 3′-untranslated regions (UTRs). The 5′-UTR contains an internal ribosomal entry site (IRES) and mediates cap-independent translation initiation while the 3′-UTR harbors multiple AU-rich (AUR) stability determinants that have been previously shown to regulate turnover of VEGF mRNA. In addition, the translation initiation of the VEGF transcript is uniquely regulated. Under hypoxic conditions, translation of most cellular transcripts mediated by cap-dependent translation initiation process is greatly impaired (Kraggerud et al., Anticancer Res., 15:683-686 (1995)). Initiation of translation of the VEGF mRNA, however, is unique under hypoxic conditions in that it is mediated via an internal ribosome entry site (IRES) within the VEGF 5′UTR (Stein et al., Mol. Cell. Biol. 18:3112-3119 (1998), Levy et al., J. Biol. Chem. 271:2746-2753 (1996), Huez et al., Mol. Cell. Biol., 18:6178-6190 (1998), Akiri et al., Oncogene, 17:227-236 (1998)). Thus, this form of post-transciptional regulation permits cells to produce large amounts of VEGF protein to support either further tumor growth or aberrant neovascularization in ocular diseases under hypoxic conditions. The stability of VEGF mRNA is also greatly enhanced as a consequence of the binding of factors to elements in the 3′-UTR (Goldberg et al., J. Biol. Cell. J. Biol. Chem., 277(16): 13635-40 (2002)).
There is a large body of experimental evidence indicating that tumor growth can be inhibited by the prevention of neovascularization (Lin et al., Cell Growth Differ., 9(1):49-58 (1998), Zhu et al., Invest. New Drugs, 17:195-212 (1999)). Tumor vessels are generally immature and constantly undergo remodeling (Carmeliet, Nat. Med., 9(6):653-60 (2003), Carmeliet et al., Nature, 407:249-257 (2000)). Active and aberrant angiogenesis is the result of a disruption in the normal balance of proangiogenic and anti-angiogenic factors, including various cytokines, growth factors and steroid hormones. Despite the complexity of the regulation of tumor angiogenesis, accumulated evidence indicates that targeting a single proangiogenic factor might be sufficient to inhibit tumor angiogenesis and suppress tumor growth (Kim et al., Nature, 362:841-844 (1993), Millauer et al., Nature, 367:576-579 (1994), Fong et al., Cancer Res., 59:99-106 (1999)). Among many angiogenesis targets, VEGF and its receptor are most attractive (Carmeliet, Nat. Med., 9(6):653-60 (2003), Ortega et al., Front. Biosci., 4:D141-52 (1999)). As noted above, treatment with a monoclonal antibody specifically targeting VEGF inhibited the growth of tumors in human xenografts implanted in nude mice. Subsequently, various approaches designed to inactivate VEGF signaling have been tested in tumor models and have proven to be highly effective in a broad range of tumor cell lines including carcinomas, sarcomas and gliomas (Ferrara et al., Endocr. Rev., 18:4-25, 1997), Kim et al., Nature, 362:841-844 (1993), Millauer et al., Nature, 367:576-579 (1994), Fong et al., Cancer Res., 59:99-106 (1999), Geng et al., Cancer Res., 61:2413-2419 (2001)). In addition, inhibition of VEGF by anti-VEGF antibody did not result in significant side effects in fully developed rodents or primates (Ryan et al, Toxicol. Pathol., 27:78-86 (1999), Ferrara et al., Nat. Med., 4:336-340 (1998)). Taken together, these results indicate that VEGF is a valid target for the development of tumor therapy. Indeed, a number of clinical trials are underway using VEGF inhibitors (Matter, Drug Discovery Today, 6:1005-1024 (2001), Hichlin et al., Drug Discovery Today, 6:517-528 (2001)).
Although several pro-angiogenic factors are implicated in the pathology of exudative age-related macular degeneration, VEGF appears to be the most critical in the pathogenesis and development of this disease (Witmer et al., Prog. Retin Eye Res., 22(1):1-29 (2003), Holash et al., Science, 284:1994-1998 (1999)). Data from preclinical experiments and clinical trials have demonstrated that blockade of VEGF alone is sufficient to alleviate or stabilize disease progression (Eyetech Study Group, 22(2):143-52 (2002), Krzystolik et al., Arch. Ophthalmol., 120(3):338-46 (2002), Shen et al., Lab Invest., 82(2):167-82 (2002), Honda et al., Gene Ther., 7(11):978-85 (2000), Saishin et al., J Cell Physiol., 195(2):241-8 (2003)). For example, inhibition of VEGFR signaling by a specific tyrosine kinase inhibitor is sufficient to completely prevent retinal neovascularization in a murine retinopathy of prematurity model (Ozaki H, Seo M S, Ozaki et al., Am. J. Pathol., 156(2):697-707 (2000)). Furthermore, it has recently been demonstrated that small interfering RNAs (siRNA) directed against murine VEGF significantly inhibited ocular neovascularization after laser photocoagulation in a mouse model (Reich et al., Mol. Vis. 30;9:210-6 (2003)). These results indicate that selective inhibition of VEGF expression is achievable and offers validation of this approach for the treatment of ocular neovascular diseases such as exudative macular degeneration and diabetic retinopathy.
Three approaches have been used to inhibit VEGF activity, including (1) neutralization of VEGF activity by using a specific antibody, soluble VEGF receptor or aptamer oligos against the VEGF/VEGFR interaction (Kim et al., Nature, 362:841-844 (1993), Lin et al., Cell Growth Differ., 9(1):49-58 (1998), Borgstrom et al., Prostate, 35:1-10 (1998), Zhu et al., Invest. New Drugs, 17:195-212 (1999), Millauer et al., Nature, 367:576-579 (1994), Asano et al., Jpn. J. Cancer Res., 90(1):93-100 (1999), Brekken et al., Cancer Res., 60(18):5117-24 (2000)); (2) inhibition of VEGFR mediated signal transduction by specific small molecule tyrosine kinase inhibitors (Fong et al., Cancer Res., 59:99-106 (1999), Wedge et al., Cancer Res., 60(4):970-5 (2000), Laird et al., Cancer Res., 60(15):4152-60 (2000)); and (3) inhibition of VEGF/VEGFR expression by using antisense, siRNA or ribozyme (Reich et al., Mol. Vis. 30;9:210-6 (2003), Parry et al., Nucleic Acids Res., 27:2569-2577 (1999), Ellis et al., Surgery, 120:871-878 (1996), Filleur et al., Cancer Res., 63(14):3919-22 (2003)). Although all of these approaches show significant inhibition of angiogenesis in vivo, they all possess significant limitations. For example, therapeutic proteins (antibody and soluble receptors) or oligos (antisense, siRNA and ribozyme) are large molecules with poor permeability that usually require parenteral administration and are costly to produce. For treatment of chronic ocular neovascularization, multiple injections may be impractical due to potential complications such as retinal detachment and procedure related infection. Moreover, tyrosine kinase inhibitors have the potential for limited specificity. VEGF is constitutively expressed at a low level in normal eyes and other tissues and thus it may be harmful to completely suppress VEGF function by administration of antibody or tyrosine kinase inhibitors systemically, especially for patients with AMD and RD many of whom are also hypertensive (Giles et al., Cancer, 97(8):1920-8 (2003), Sugimoto et al., J. Biol. Chem., 278(15):12605-8 (2003), Bergsland et al., American Society of Clinical Oncology 36th Annual Meeting, 20-23 May, 2000, New Orleans, La., USA, Abstract 939), DeVore et al., American Society of Clinical Oncology 36th Annual Meeting, 20-23 May, 2000, New Orleans, La., USA, Abstract 1896).
Thus, there remains a need to develop, characterize and optimize lead molecules for the development of novel anti-angiogenesis drugs. Accordingly, it is an object of the present invention to provide such compounds.
All documents referred to herein are incorporated by reference into the present application as though fully set forth herein.
In accordance with the present invention, compounds that inhibit the expression of VEGF post-transcriptionally have been identified, and methods for their use provided.
In one aspect of the invention, compounds of Formulas (I), (II) and (III), including Formulas (I-a) to (I-l), are provided which are useful in the inhibition of VEGF production, in the inhibition of angiogenesis, and/or in the treatment of cancer, diabetic retinopathy or exudative macular degeneration.
In another aspect of the invention, methods are provided for the inhibition of VEGF production, the inhibition of angiogenesis, and/or the treatment of cancer, diabetic retinopathy, rheumatoid arthritis, psoriasis, atherosclerosis, chronic inflammation, other chronic inflammation-related diseases and disorders, obesity, or exudative macular degeneration using the compounds described herein.
In one embodiment, the invention is directed to methods for inhibiting VEGF production comprising administering a VEGF-expression inhibiting amount of at least one compound of the invention to a subject in need thereof.
In another embodiment, methods for inhibiting angiogenesis are provided comprising administering an anti-angiogenic amount of at least one compound of the invention to a subject in need thereof.
The present invention also provides methods for treating a solid tumor cancer comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention also provides methods for treating a Wilms tumor comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention also provides methods for treating a neuroblastoma comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention further provides methods of treating a malignant melanoma comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention yet further provides methods for treating cervical cancer comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention also provides methods for treating lung cancer comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention also provides methods for treating colon cancer comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention further provides methods for treating a solid tumor cancer by post-transcriptionally modifying VEGF expression comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention yet further provides methods for treating a solid tumor cancer by slowing tumorigenesis at a pre-vascular stage comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention also provides methods for treating a solid tumor cancer by reducing tumor VEGF levels comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention further provides methods for treating a solid tumor cancer by reducing perivascularly sequestered VEGF comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention also provides methods of inhibiting VEGF mRNA translation comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention further provides methods of slowing tumorigenesis at a pre-vascular stage comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention yet further provides methods of reducing tumor VEGF levels comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention also provides methods of reducing plasma VEGF levels comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention further provides methods of reducing perivascularly sequestered VEGF comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention yet further provides methods of treating a solid tumor cancer comprising measuring plasma levels of VEGF, tumor levels of VEGF, or both, and administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer of said compound, to a subject in need thereof.
The present invention also provides methods of diagnosing solid tumor cancers comprising measuring plasma levels of VEGF.
The present invention further provides methods of diagnosing solid tumor cancers comprising measuring tumor levels of VEGF.
The present invention yet further provides methods of treating a solid tumor cancer comprising administering a therapeutically effective amount of a compound of Formula (I), or a pharmaceutically acceptable salt, hydrate, solvate, clathrate, polymorph, racemate or stereoisomer thereof, together with one or more additional agents useful for treating cancer to a subject in need thereof.
These and other aspects of the invention will be more clearly understood with reference to the following preferred embodiments and detailed description.
Aberrant up-regulation of Vascular Endothelial Growth Factor (VEGF), a key factor for angiogenesis, is an important contributor to the pathogenesis of disease states such as cancer, diabetic retinopathy, rheumatoid arthritis, psoriasis, atherosclerosis, chronic inflammation, other chronic inflammation-related diseases and disorders, obesity, or exudative macular degeneration. In accordance with the present invention, compounds that inhibit the expression of VEGF post-transcriptionally have been identified, and methods for their use provided. The compounds of the invention have nanomolar to sub-nanomolar activity for the inhibition of VEGF expression.
A. Compounds of the Invention
In one aspect of the invention, compounds are provided which are useful in the inhibition of VEGF production, in the inhibition of angiogenesis, and/or in the treatment of cancer, diabetic retinopathy or exudative macular degeneration. In certain embodiments, the compounds of the invention specifically inhibit VEGF production, while in other embodiments, the compounds of the invention inhibit VEGF expression as well as that of other angiogenesis factors such as FGF-2. In this regard, pan-angiogenic inhibitor may be preferred in methods of inhibiting tumor growth, while VEGF specific inhibitors may be preferred for the treatment of ocular neovascular disorders (Eyetech Study Group, 22(2): 143-52 (2002)).
The compounds of the invention generally include one or more chiral centers, and as such may exist as racemic mixtures (R/S) or as enantiomerically pure compositions. The compounds may exist as (R) or (S) isomers (when one chiral center is present) in enantiomerically pure compositions. In a preferred embodiment, the compounds of the invention are the (S) isomers and may exist as enantiomerically pure compositions comprising only the (S) isomer. As one of skill will recognize, when more than one chiral center is present, the compounds of the invention may exist as (R,R), (R,S), (S,R), (S,S), etc. isomer. Preferred compounds included (S,S) and (S,R) isomers.
As used herein, “enantiomerically pure” refers to compositions consisting substantially of a single isomer, preferably consisting of greater than or equal to 90%, 92%, 95%, 98%, 99%, or equal to 100% of a single isomer.
As used herein, a “racemic mixture” is any mixture of isometric forms that are not “enantiomerically pure,” including, without limitation, about 50/50, about 60/40, and about 70/30 mixtures.
Preferred compounds of the present invention useful in the inhibition of VEGF production include those of Formula (I) as shown below.
wherein,
As will be evident to one of skill in the art, the compounds of Formula (I) comprise at least one stereocenter (e.g., at the R1 substituent), and may exist as a racemic mixture or as an enantiomerically pure composition. In a preferred embodiment, the compounds of Formula (I) are the (S) isomer, in an enantiomerically pure composition.
As used herein, the term “alkyl” generally refers to saturated hydrocarbyl radicals of straight, branched or cyclic configuration including methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, octyl, n-octyl, and the like. In some embodiments, alkyl substituents may be include C1 to C8, C1 to C6, or C1 to C4 alkyl groups. The alkyl group may be optionally substituted with one or more halogen or alkoxy groups. For instance, the alkyl group may be a haloalkyl, dihaloalkyl, or trihaloalkyl.
As used herein, “alkenyl” generally refers to linear, branched or cyclic alkene radicals having one or more carbon-carbon double bonds, such as C2 to C8 and C2 to C6 alkenyl groups, including 3-propenyl.
As used herein, “alkynyl” generally refers to linear, branched or cyclic alkyne radicals having one or more carbon-carbon triple bonds, such as C2 to C8 and C2 to C6 alkynyl groups, including hex-3-yne.
As used herein, “aryl” refers to a carbocyclic aromatic ring structure. Included in the scope of aryl groups are aromatic rings having from five to twenty carbon atoms. Aryl ring structures include compounds having one or more ring structures, such as mono-, bi-, or tricyclic compounds. Examples of aryl groups that include phenyl, tolyl, anthracenyl, fluorenyl, indenyl, azulenyl, phenanthrenyl (i.e., phenanthrene), and napthyl (i.e., napthalene) ring structures. In certain embodiments, the aryl group may be optionally substituted.
As used herein, “heteroaryl” refers to cyclic aromatic ring structures in which one or more atoms in the ring, the heteroatom(s), is an element other than carbon. Heteroatoms are typically O, S or N atoms. Included within the scope of heteroaryl, and independently selectable, are O, N, and S heteroaryl ring structures. The ring structure may include compounds having one or more ring structures, such as mono-, bi-, or tricyclic compounds. In some embodiments, the heteroaryl groups may be selected from heteroaryl groups that contain one or more heteroatoms, two or more heteroatoms, three or more heteroatoms, or four or more heteroatoms. Heteroaryl ring structures may be selected from those that contain five or more atoms, six or more atoms, or eight or more atoms. Examples of heteroaryl ring structures include: acridine, benzimidazole, benzoxazole, benzodioxole, benzofuran, dihydro-chromen-4-only, 1,3-diazine, 1,2-diazine, 1,2-diazole, 1,4-diazanaphthalene, furan, furazan, imidazole, indole, isoxazole, isoquinoline, isothiazole, isoindolyl, oxazole, purine, pyridazine, pyrazole, pyridine, pyrazine, pyrimidine, pyrrole, quinoline, quinoxaline, thiazole, thiophene, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole and quinazoline. In certain embodiments, the heteroaryl may be optionally substituted.
As used herein, “heterocycle” refers to cyclic ring structures in which one or more atoms in the ring, the heteroatom(s), is an element other than carbon. Heteroatoms are typically O, S or N atoms. Included within the scope of heterocycle, and independently selectable, are O, N, and S heterocycle ring structures. The ring structure may include compounds having one or more ring structures, such as mono-, bi-, or tricyclic compounds. In some embodiments, the heterocycle groups may be selected from heterocycle groups that contain one or more heteroatoms, two or more heteroatoms, three or more heteroatoms, or four or more heteroatoms. Example of heterocycle groups include morpholinyl, pyrrolidinonyl, pyrrolidinyl, piperidinyl, piperazinyl, hydantoinyl, valerolactamyl, oxiranyl, oxetanyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydropyridinyl, tetrahydroprimidinyl, tetrahydrothiophenyl or tetrahydrothiopyranyl and the like. In certain embodiments, the heterocycle may optionally be substituted.
As used herein, “alkanoyl” generally refers to a group with the structure —C(O)—R. In certain embodiments, R may be a hydrogen, an alkyl, an 4-morpholinyl group, or a thiazoleamino group.
As used herein, “alkoxy” generally refers to a group with the structure —O—R. In certain embodiments, R may be an alkyl group, such as a C1 to C5 alkyl group.
For the purposes of this invention, halo substituents may be independently selected from the halogens such as fluorine, chlorine, bromine, iodine, and astatine.
In certain preferred embodiments, X may be hydrogen, methoxy, hydroxyl, benzoxy, or a halogen, preferably bromide or chloride. In other embodiments, X may preferably be a C1 to C4 alkyl or a haloalkyl.
R1 may preferably be a C6 to C8 aryl group, optionally substituted with at least one Ro group. Ro may then preferably be methoxy, benzoxy, a C1 to C6 alkyl, a 5 to 6 membered heteroaryl (such as furyl or imidazole), cyano, nitro, tri-fluro methyl, or a halogen, more preferably methoxy, benzoxy, iso-butyl or a halogen, and more preferably methoxy, iso-butyl, bromide or chloride. Alternatively, R1 may be a 5 to 10 membered heteroaryl or 3 to 12 membered heterocycle, such as a pyridinyl group, a thiophene group, a furyl group, a tetrahydro furyl group, and a thiazole group dihydro-chromen-4-onyl group, a 1H-isoindolyl group, or a benzodioxole group.
R2 may preferably be a —CH2-furyl group, a pyrimidyl group, or a —C(O)O—Rd group. Rd may preferably then be a C1 to C6 alkyl, optionally substituted with at least one halogen; or a C5 to C6 aryl, optionally substituted with at least one methyl, methoxy, or halogen.
Preferred R1 substituents also include the following, where the * indicates the bond of attachment to the carboline scaffold molecule.
Other preferred R1 substituents include the following, where the * indicates the bond of attachment to the carboline scaffold molecule.
Preferred R2 substituents also include the following, where the * indicates the bond of attachment to the carboline scaffold molecule.
Other preferred R2 substituents include the following, where the * indicates the bond of attachment to the carboline scaffold molecule.
Preferred R3 substituents include the following, where the * indicates the bond of attachment to the carboline scaffold molecule.
A preferred class of compounds within Formula (I) include those compounds of Formula (I-a) as shown below.
Another preferred class of compounds within Formula (I) include those compounds of Formula (I-b) as shown below.
wherein:
Other preferred classes of compounds within Formula (I) include the following.
It is understood that substituents X and R1, Rc, Rd, and Re of the compounds of Formulas (I-c) to (I-i) are defined as in Formula (I).
In other embodiments, preferred compounds of the present invention useful in the inhibition of VEGF production include those of Formulas (I-i) through (I-l), as shown below. In the embodiments of Formulas (I-j) through (I-l), substituents X, R1, R2, R3, etc. are defined as in Formula (I), as well as Formulas (I-a) to (I-i).
Also included within the scope of the invention are pharmaceutically acceptable salts, hydrates, solvates, calthrates, polymorphs, racemates and stereoisomers of the compounds described herein.
In another aspect of the invention, preferred compounds of the present invention useful in the inhibition of VEGF production include those of Formula (I-l) as shown below.
wherein,
In another embodiment, compounds of Formulas (II), (III) and (IV) are provided, which are useful for inhibiting VEGF production, and treating cancer.
Wherein X, R1, R2, Ro and Rd are defined as described above with regard with Formula (I).
For the purposes of this invention, where one or more functionalities encompassing X R1, R2, R0, Ra, Rb, Rc, Rd, and Re, are incorporated into a molecule of Formulas (I), (II), and (III), including Formulas (I-a) to (I-k), each of the functionalities appearing at any location within the disclosed may be independently selected, and as appropriate, independently substituted. Further, where a more generic substituent is set forth for any position in the molecules of the present invention, it is understood that the generic substituent may be replaced with more specific substituents, and the resulting molecules are within the scope of the molecules of the present invention.
Preferred compounds of the invention include the following.
In certain embodiments, preferred compounds include those with an EC50 in the VEGF ELISA assay described in Example 5 of less than about 2 uM, more preferably between about 2 uM and about 0.04 uM (200 nM to 40 nM); more preferably from about 0.04 uM to about 0.008 uM to (40 nM to 8 nM); and more preferably less than about 0.008 uM (<8 nM). Particularly preferred compounds are Compound Nos: 2, 4, 5, 7, 8, 10, 11, 12, 17, 23, 25, 81, 102, 112, 140, 328, 329, 330, 331, 332, 355, 816, 817, 818, 823, 824, 825, 830, 831, 832, 837, 838, 841, 842, 843, and regioisomers thereof. In one embodiment, the preferred compounds of the invention form a racemic mixture, and in another embodiment the compounds of the invention are the (R), (S), (R,R), (S,S), (R,S), (S,R) isomer, in an enantiomerically pure composition. More preferably, the compounds of the invention are the (S) isomers, in an enantiomerically pure composition.
The above compounds are listed only to provide examples that may be used in the methods of the invention. Based upon the instant disclosure, the skilled artisan would recognize other compounds intended to be included within the scope of the presently claimed invention that would be useful in the methods recited herein.
B. Preparation of Compounds of the Invention
Compounds of the invention may be produced in any manner known in the art. By way of example, compounds of the invention may be prepared according to the following general schemes. More specifically, Scheme I may be used to make compounds of Formula I. Scheme Ia can be used when in conjunction with Scheme I when R2 is a —CH2-furanyl group. Alternatively, for asymmetric synthesis when R2 is hydrogen or hydroxyl, Scheme Ib may be used.
Scheme II can be used to prepare compounds of Formula I-h.
Scheme IIIa or IIIb can be used to prepare compounds of Formula I-i.
Ref: Magid Abou-Gharbia et al, J. Med. Chem. 1987, 30, 1818.
In a preferred embodiment, compounds of the invention may be resolved to enantiomerically pure compositions using any method known in art. By way of example, compounds of the invention may be resolved by direct crystallization of enantiomer mixtures, by diastereomer salt formation of enantiomers, by the formation of diasteriomers and separation, or by enzymatic resolution.
In a preferred embodiment, compounds of the invention may be resolved through crystallization using, e.g., N-acetyl-L-phenylalanine to obtain the (S) isomer, or N-acetyl-D-phenylalanine to obtain the (R) isomer, in a manner similar to that illustrated in Scheme IV.
In certain embodiments, exemplary methods of Scheme I for preparing preferred compounds of Formula I involve the formation of free amine Pictet-Spengler reaction products/intermediates, as described below in Procedure-I.
In one embodiment, Procedure-I may involve adding a desired Aldehyde (II) to a suspension of 5-substituted tryptamine. HCl (I) in 0.1N sulfuric acid. The solution may then be stirred at about 110° C.-120° C. in a closed reaction vessel until the reaction is sufficient to complete, e.g., for about 15 minutes to about 20 hours. After completion of the reaction, the reaction mixture may be cooled to room temperature and the precipitated salt may be filtered. The filtered residue may then be washed with ether, EtOAc or a mixture of DCM and DMF and dried to give the product (III) as acid salt. Alternatively, a desired Aldehyde (II) may be added to a suspension of 5-substituted tryptamine.HCl (I) in acetic acid and refluxed until the reaction is sufficiently complete, e.g., for about 15 minutes to about 20 hours. After completion of the reaction, the reaction mixture may be cooled to room temperature and the acid salt may be filtered. The filtered residue may then be washed with acetic acid followed by DCM and dried to give the product (III) as acid salt. The free amine (III) may be obtained by extraction with EtOAc and washing with aqueous ammonium hydroxide or 1M aq. sodium hydroxide.
The free amine, or its salt, may then be used to form other preferred compounds of Formula I, such as carbamate analogs (Formula I-c, Procedure-II), amide analogs, including N-acetyl analogs (Formula I-c, Procedure-IIIa and Procedure-IIIb), urea and thiourea analogs (Formula I-e and I-f, Procedure-IV and Procedure-V respectively), sulfoxide analogs (Formula I-g, Procedure-VI), and pyrimidine analogs (Procedure-VII).
More particularly, Procedure-II may be used to synthesize carbamate analogs of free amines (III), or their salts.
In accordance with Procedure-II, diisopropylethylamine (DIEA) may be added to the free amine (III), or its acid salt in dichloromethane (DCM), followed by slow addition of substituted chloroformate. The reaction mixture may be stirred at room temperature for about 1 to 20 hours. The solvent may then be evaporated and the crude product may either be purified by HPLC or silica gel column chromatography.
Procedure-IIIa may be used to synthesize amide analogs of free amine (III), or their salts.
In accordance with Procedure-IIIa, a 15 min pre-stirred mixture of an R2-acid and diisopropyl carbodiimide (DIC) may be added to the free amine (III), or its acid salt in DCM and DIEA. The reaction mixture may be stirring for about 1 h. The solvents may then be evaporated and the crude product purified by HPLC.
Alternatively, Procedure-IIIb may be used to synthesize N-acetyl analogs of free amines (III), or their salts.
In accordance with Procedure-IIIb, pyridine may be added to the free amine (III), or its acid salt in DCM, followed by acetic anhydride. The reaction mixture may be stirred at room temperature for about 8 to 20 hours. The solvents may then be evaporated and the crude product was purified by HPLC.
In accordance with Procedure-IV, DIEA and R2-isocyanate may be added to the free amine (III), or its acid salt in DCM. The reaction mixture may be refluxed for about 1.5 h. The solvents may then be evaporated and the crude product purified by HPLC.
Procedure-V may be used to synthesize thiourea analogs of free amines (III), or their salts.
In accordance with Procedure-V, DIEA and R2-isothiocyanate may be added to the free amine (III), or its acid salt in DCM. The reaction mixture may be refluxed for about 12 h. The solvents may then be evaporated and the crude product purified by HPLC.
Procedure-VI may be used to synthesize sulfonyl analogs of free amines (III), or their salts.
In accordance with Procedure-VI, DIEA and R2-sulfonylchloride may be added to the free amine (III), or its acid salt in DCM. The reaction mixture may be stirred at room temperature for about 12 h. The solvents may then be evaporated and the crude product purified by HPLC. Procedure-VII may be used to synthesize pyrimidine analogs of free amines (III), or their salts.
In accordance with Procedure-VII, triethylamine and 2-bromopyrimidine in N,N-dimethylformamide (DMF) may be added to the free amine (III), or its acid salt in DCM. The reaction mixture may be heated to about 120° C. for about 12 h. The solvents may then be evaporated and the crude product purified by HPLC.
These and other reaction methodologies may be useful in preparing the compounds of the invention, as recognized by one of skill in the art. Various modifications to the above schemes and procedures will be apparent to one of skill in the art, and the invention is not limited specifically by the method of preparing the compounds of the invention.
C. Methods of the Invention
In another aspect of the invention, methods are provided for the inhibition of VEGF production, the inhibition of angiogenesis, and/or the treatment of cancer, diabetic retinopathy, rheumatoid arthritis, psoriasis, atherosclerosis, chronic inflammation, other chronic inflammation-related diseases and disorders, obesity, or exudative macular degeneration using the compounds described herein.
In one embodiment, the invention is directed to methods for inhibiting VEGF production comprising administering a VEGF-expression inhibiting amount of at least one compound of the invention to a subject in need thereof.
In another embodiment, methods for inhibiting angiogenesis are provided comprising administering an anti-angiogenic amount of at least one compound of the invention to a subject in need thereof.
In yet another embodiment, methods for treating cancer, diabetic retinopathy, rheumatoid arthritis, psoriasis, atherosclerosis, chronic inflammation, other chronic inflammation-related diseases and disorders, obesity, or exudative macular degeneration are provided comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof.
In yet a further embodiment, the cancers which can be treated by administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof include solid tumor cancers. Solid tumor cancers that can be treated by the present invention include solid tumor carcinomas and solid tumor sarcomas. Solid tumor carcinomas include, but are not limited to, pediatric solid tumors, such as Wilms tumor and neuroblastoma, and carcinomas of the epidermis, such as malignant melanomas, as well as lung cancers, cervical cancers, colon cancers and renal cancers. Solid tumor sarcomas include, but are not limited to, fibrosarcomas. The methods of treating cancer can further include the administration of one or more additional agents useful for treating cancer.
In yet another embodiment of the invention, methods for treating a solid tumor cancer by slowing tumorigenesis at a pre-vascular stage are provided, comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof, either alone or together with one or more additional agents useful for treating cancer.
In another embodiment of the invention, methods for treating a solid tumor cancer by inhibiting VEGF mRNA translation are provided, comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof, either alone or together with one or more additional agents useful for treating cancer.
In yet another embodiment of the invention methods for treating a solid tumor cancer by reducing tumor VEGF levels are provided, comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof, either alone or together with one or more additional agents useful for treating cancer.
In yet a further embodiment of the invention, methods for treating a solid tumor cancer by reducing perivascularly sequestered or intratumoral VEGF are provided, comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof, either alone or together with one or more additional agents useful for treating cancer. In this aspect, reduced perivascularly sequestered VEGF is an in situ comparison of perivascular VEGF in tumors treated with the compound of the invention and tumors not treated with the compound of the invention. In a preferred aspect, reduced perivascularly sequestered VEGF is compared with levels of perivascular VEGF in tumors treated with antibodies to VEGF.
Without intending to be limited by theory, it is believed that the methods of the present invention act through a combination of mechanisms that modulate the activity of VEGF. In this embodiment of the invention, methods for inhibiting VEGF mRNA translation are provided, comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof. In a preferred aspect, VEGF mRNA translation is inhibited by greater than 10%, 25%, 50%, 75%, 80%, or 90% compared with an untreated tumor or cell.
In another embodiment of the invention, methods for slowing tumorigenesis at a pre-vascular stage are provided, comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof, either alone or together with one or more additional cancer agents. The pre-vascular stage of tumorigenesis is clinically known as “carcinoma in situ” and tumors at this stage are characterized by their reliance on nearby blood vessels for oxygen and diffusion of nutrients, due to the tumors absence of its own vascular infrastructure. So, by slowing tumorigenesis at a pre-vascular stage, one is preventing or slowing the development of a vascular infrastructure in the tumor. In this embodiment of the invention, whether tumorigenesis has been slowed at the pre-vascular stage is determined by identifying to what extent the tumor has developed a vascular infrastructure. In a preferred aspect, treated tumor growth is prevented or slowed, as compared to the untreated tumors, by 90%, 80%, 70%, 60%, 50%, 40%, 30%, 20% or 10%.
In yet a further embodiment of the invention, methods for reducing perivascularly sequestered or intratumoral VEGF are provided, comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof.
In yet an additional embodiment of the invention, methods of diagnosing cancer by measuring tumor and/or plasma levels of VEGF are provided. Tumor levels of VEGF can be measured using biopsy tissue, where plasma VEGF levels can be measured by taking blood. In humans, different tumors secrete different levels of VEGF. Standard ELISA procedures can be used to measure the amount of VEGF in the tumor or plasma. See, for example, Verheul, H. M. W. et al. (2000) Platelet and coagulation activation with vascular endothelial growth factor generation in soft tissue sarcomas. Clin. Cancer Res. 6:166. For tumors that do not secrete large amounts of VEGF into the plasma, the tumor VEGF concentration can be determined to diagnose the tumor progression. For tumors that do secrete large amount of VEGF into the plasma, plasma VEGF concentration can be determined to diagnose the tumor progression. After most known cancer treatments, VEGF levels are not affected, and therefore the plasma or tumor levels of VEGF do not predict efficacy of the treatment (i.e., progression of the cancer). Compounds of the present invention can affect VEGF levels, both in the plasma and tumor, and therefore measuring VEGF levels is an accurate way to monitor and/or predict the progression of the cancer (i.e., the efficacy of the treatment) when the methods of the present invention are used for treating cancer.
In yet another embodiment of the invention, methods for reducing tumor or plasma VEGF levels are provided, comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof. In this embodiment, VEGF levels can be measured in a tumor not treated with the compounds of the present invention and the VEGF levels compared to the VEGF levels measured in a tumor treated with the compounds of the present invention, thereby showing that by treatment of tumors with the compounds of the present invention VEGF levels are reduced.
In yet another embodiment of the invention, methods for treating a solid tumor cancer are provided, comprising (a) measuring plasma VEGF levels, tumor VEGF levels, or both, and administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof. In an embodiment, VEGF concentration is measured to determine whether treatment with a compound of the present invention should be undertaken. In this aspect, treatment with a compound of the present invention is preferred and more effective as the VEGF levels increase.
In yet a further embodiment of the invention, methods for treating a solid tumor cancer are provided, comprising administering a therapeutically effective amount of at least one compound of the invention to a subject in need thereof, together with one or more additional cancer agents.
In preferred embodiments, the methods of the invention comprise administering a therapeutically effective amount of at least one compound of the invention, wherein the compound is an (S) isomer.
According to the methods of the invention, the compound(s) may be administered to the subject via any drug delivery route known in the art. Specific exemplary administration routes include oral, ocular, rectal, buccal, topical, nasal, ophthalmic, subcutaneous, intramuscular, intravenous (bolus and infusion), intracerebral, transdermal, and pulmonary.
The terms “VEGF-inhibiting amount”, “anti-angiogenic amount”, and “therapeutically effective amount”, as used herein, refer to an amount of a pharmaceutical agent to treat, ameliorate, or prevent the identified disease or condition, or to exhibit a detectable therapeutic or inhibitory affect. The affect can be detected by, for example, the assays disclosed in the following examples. The precise effective amount for a subject will depend upon the subject's body weight, size, and health; the nature and extent of the condition; and the therapeutic or combination of therapeutics selected for administration. Therapeutically effective amounts for a given situation can be determined by routine experimentation that is within the skill and judgment of the clinician.
For any compound, the therapeutically effective amount can be estimated initially either in cell culture assays, e.g., of neoplastic cells, or in animal models, usually rats, mice, rabbits, dogs, or pigs. The animal model may also be used to determine the appropriate concentration range and route of administration. Such information can then be used to determine useful doses and routes for administration in humans. Therapeutic/prophylactic efficacy and toxicity may be determined by standard pharmaceutical procedures in cell cultures or experimental animals, e.g., ED50 (the dose therapeutically effective in 50% of the population) and LD50 (the dose lethal to 50% of the population). The dose ratio between therapeutic and toxic effects is the therapeutic index, and it can be expressed as the ratio, ED50/LD50. Pharmaceutical compositions that exhibit large therapeutic indices are preferred. The data obtained from cell culture assays and animal studies may be used in formulating a range of dosage for human use. The dosage contained in such compositions is preferably within a range of circulating concentrations that include an ED50 with little or no toxicity. The dosage may vary within this range depending upon the dosage form employed, sensitivity of the patient, and the route of administration.
More specifically, the concentration-biological effect relationships observed with regard to the compound(s) of the present invention indicate an initial target plasma concentration ranging from approximately 0.1 μg/mL to approximately 100 μg/mL, preferably from approximately 5 μg/mL to approximately 50 μg/mL, more preferably from approximately 5 μg/mL to approximately 10 μg/mL. To achieve such plasma concentrations, the compounds of the invention may be administered at doses that vary from 0.1 μg to 100,000 mg, depending upon the route of administration. Guidance as to particular dosages and methods of delivery is provided in the literature and is generally available to practitioners in the art. In general the dose will be in the range of about 1 mg/day to about 10 g/day, or about 0.1 g to about 3 g/day, or about 0.3 g to about 3 g/day, or about 0.5 g to about 2 g/day, in single, divided, or continuous doses for a patient weighing between about 40 to about 100 kg (which dose may be adjusted for patients above or below this weight range, particularly children under 40 kg).
The exact dosage will be determined by the practitioner, in light of factors related to the subject that requires treatment. Dosage and administration are adjusted to provide sufficient levels of the active agent(s) or to maintain the desired effect. Factors which may be taken into account include the severity of the disease state, general health of the subject, age, weight, and gender of the subject, diet, time and frequency of administration, drug combination(s), reaction sensitivities, and tolerance/response to therapy. Long-acting pharmaceutical compositions may be administered every 3 to 4 days, every week, or once every two weeks depending on half-life and clearance rate of the particular formulation.
D. Metabolites of the Compounds of the Invention
Also falling within the scope of the present invention are the in vivo metabolic products of the compounds described herein. Such products may result for example from the oxidation, reduction, hydrolysis, amidation, esterification and the like of the administered compound, primarily due to enzymatic processes. Accordingly, the invention includes compounds produced by a process comprising contacting a compound of this invention with a mammalian tissue or a mammal for a period of time sufficient to yield a metabolic product thereof. Such products typically are identified by preparing a radio-labeled (e.g. C14 or H3) compound of the invention, administering it in a detectable dose (e.g., greater than about 0.5 mg/kg) to a mammal such as rat, mouse, guinea pig, monkey, or to man, allowing sufficient time for metabolism to occur (typically about 30 seconds to 30 hours), and isolating its conversion products from urine, blood or other biological samples. These products are easily isolated since they are labeled (others are isolated by the use of antibodies capable of binding epitopes surviving in the metabolite). The metabolite structures are determined in conventional fashion, e.g., by MS or NMR analysis. In general, analysis of metabolites may be done in the same way as conventional drug metabolism studies well-known to those skilled in the art. The conversion products, so long as they are not otherwise found in vivo, are useful in diagnostic assays for therapeutic dosing of the compounds of the invention even if they possess no biological activity of their own.
E. Pharmaceutical Compositions of the Invention
While it is possible for the compounds of the present invention to be administered neat, it may be preferable to formulate the compounds as pharmaceutical compositions. As such, in yet another aspect of the invention, pharmaceutical compositions useful in the methods of the invention are provided. The pharmaceutical compositions of the invention may be formulated with pharmaceutically acceptable excipients such as carriers, solvents, stabilizers, adjuvants, diluents, etc., depending upon the particular mode of administration and dosage form. The pharmaceutical compositions should generally be formulated to achieve a physiologically compatible pH, and may range from a pH of about 3 to a pH of about 11, preferably about pH 3 to about pH 7, depending on the formulation and route of administration. In alternative embodiments, it may be preferred that the pH is adjusted to a range from about pH 5.0 to about pH 8.0.
More particularly, the pharmaceutical compositions of the invention comprise a therapeutically or prophylactically effective amount of at least one compound of the present invention, together with one or more pharmaceutically acceptable excipients. Optionally, the pharmaceutical compositions of the invention may comprise a combination of compounds of the present invention, or may include a second active ingredient useful in the treatment of cancer, diabetic retinopathy, or exudative macular degeneration.
Formulations of the present invention, e.g., for parenteral or oral administration, are most typically solids, liquid solutions, emulsions or suspensions, while inhaleable formulations for pulmonary administration are generally liquids or powders, with powder formulations being generally preferred. A preferred pharmaceutical composition of the invention may also be formulated as a lyophilized solid that is reconstituted with a physiologically compatible solvent prior to administration. Alternative pharmaceutical compositions of the invention may be formulated as syrups, creams, ointments, tablets, and the like.
The term “pharmaceutically acceptable excipient” refers to an excipient for administration of a pharmaceutical agent, such as the compounds of the present invention. The term refers to any pharmaceutical excipient that may be administered without undue toxicity. Pharmaceutically acceptable excipients are determined in part by the particular composition being administered, as well as by the particular method used to administer the composition. Accordingly, there exists a wide variety of suitable formulations of pharmaceutical compositions of the present invention (see, e.g., Remington's Pharmaceutical Sciences).
Suitable excipients may be carrier molecules that include large, slowly metabolized macromolecules such as proteins, polysaccharides, polylactic acids, polyglycolic acids, polymeric amino acids, amino acid copolymers, and inactive virus particles. Other exemplary excipients include antioxidants such as ascorbic acid; chelating agents such as EDTA; carbohydrates such as dextrin, hydroxyalkylcellulose, hydroxyalkylmethylcellulose, stearic acid; liquids such as oils, water, saline, glycerol and ethanol; wetting or emulsifying agents; pH buffering substances; and the like. Liposomes are also included within the definition of pharmaceutically acceptable excipients.
The pharmaceutical compositions of the invention may be formulated in any form suitable for the intended method of administration. When intended for oral use for example, tablets, troches, lozenges, aqueous or oil suspensions, non-aqueous solutions, dispersible powders or granules (including micronized particles or nanoparticles), emulsions, hard or soft capsules, syrups or elixirs may be prepared. Compositions intended for oral use may be prepared according to any method known to the art for the manufacture of pharmaceutical compositions, and such compositions may contain one or more agents including sweetening agents, flavoring agents, coloring agents and preserving agents, in order to provide a palatable preparation.
Pharmaceutically acceptable excipients particularly suitable for use in conjunction with tablets include, for example, inert diluents, such as celluloses, calcium or sodium carbonate, lactose, calcium or sodium phosphate; disintegrating agents, such as croscarmellose sodium, cross-linked povidone, maize starch, or alginic acid; binding agents, such as povidone, starch, gelatin or acacia; and lubricating agents, such as magnesium stearate, stearic acid or talc. Tablets may be uncoated or may be coated by known techniques including microencapsulation to delay disintegration and adsorption 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 alone or with a wax may be employed.
Formulations for oral use may be also presented as hard gelatin capsules where the active ingredient is mixed with an inert solid diluent, for example celluloses, lactose, calcium phosphate or kaolin, or as soft gelatin capsules wherein the active ingredient is mixed with non-aqueous or oil medium, such as glycerin, propylene glycol, polyethylene glycol, peanut oil, liquid paraffin or olive oil.
In another embodiment, pharmaceutical compositions of the invention may be formulated as suspensions comprising a compound of the present invention in admixture with at least one pharmaceutically acceptable excipient suitable for the manufacture of a suspension. In yet another embodiment, pharmaceutical compositions of the invention may be formulated as dispersible powders and granules suitable for preparation of a suspension by the addition of suitable excipients.
Excipients suitable for use in connection with suspensions include suspending agents, such as sodium carboxymethylcellulose, methylcellulose, hydroxypropyl methylcelluose, sodium alginate, polyvinylpyrrolidone, gum tragacanth, gum acacia, dispersing or wetting agents such as a naturally occurring phosphatide (e.g., lecithin), a condensation product of an alkylene oxide with a fatty acid (e.g., polyoxyethylene stearate), a condensation product of ethylene oxide with a long chain aliphatic alcohol (e.g., heptadecaethyleneoxycethanol), a condensation product of ethylene oxide with a partial ester derived from a fatty acid and a hexitol anhydride (e.g., polyoxyethylene sorbitan monooleate); and thickening agents, such as carbomer, beeswax, hard paraffin or cetyl alcohol. The suspensions may also contain one or more preservatives such as acetic acid, methyl and/or n-propyl p-hydroxy-benzoate; one or more coloring agents; one or more flavoring agents; and one or more sweetening agents such as sucrose or saccharin.
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, such as olive oil or arachis oil, a mineral oil, such as liquid paraffin, or a mixture of these. Suitable emulsifying agents include naturally-occurring gums, such as gum acacia and gum tragacanth; naturally occurring phosphatides, such as soybean lecithin, esters or partial esters derived from fatty acids; hexitol anhydrides, such as sorbitan monooleate; and condensation products of these partial esters with ethylene oxide, such as polyoxyethylene sorbitan monooleate. The emulsion may also contain sweetening and flavoring agents. Syrups and elixirs may be formulated with sweetening agents, such as glycerol, sorbitol or sucrose. Such formulations may also contain a demulcent, a preservative, a flavoring or a coloring agent.
Additionally, the pharmaceutical compositions of the invention may be in the form of a sterile injectable preparation, such as a sterile injectable aqueous emulsion or oleaginous suspension. This emulsion or 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, such as a solution in 1,2-propane-diol. The sterile injectable preparation may also be prepared as a lyophilized powder. 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 may be 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 may likewise be used in the preparation of injectables.
Generally, the compounds of the present invention useful in the methods of the present invention are substantially insoluble in water and are sparingly soluble in most pharmaceutically acceptable protic solvents and in vegetable oils. However, the compounds are generally soluble in medium chain fatty acids (e.g., caprylic and capric acids) or triglycerides and have high solubility in propylene glycol esters of medium chain fatty acids. Also contemplated in the invention are compounds which have been modified by substitutions or additions of chemical or biochemical moieties which make them more suitable for delivery (e.g., increase solubility, bioactivity, palatability, decrease adverse reactions, etc.), for example by esterification, glycosylation, PEGylation, etc.
In a preferred embodiment, the compounds of the present invention may be formulated for oral administration in a lipid-based formulation suitable for low solubility compounds. Lipid-based formulations can generally enhance the oral bioavailability of such compounds. As such, a preferred pharmaceutical composition of the invention comprises a therapeutically or prophylactically effective amount of a compound of the present invention, together with at least one pharmaceutically acceptable excipient selected from the group consisting of: medium chain fatty acids or propylene glycol esters thereof (e.g., propylene glycol esters of edible fatty acids such as caprylic and capric fatty acids) and pharmaceutically acceptable surfactants such as polyoxyl 40 hydrogenated castor oil.
In an alternative preferred embodiment, cyclodextrins may be added as aqueous solubility enhancers. Preferred cyclodextrins include hydroxypropyl, hydroxyethyl, glucosyl, maltosyl and maltotriosyl derivatives of α-, β-, and γ-cyclodextrin. A particularly preferred cyclodextrin solubility enhancer is hydroxypropyl-β-cyclodextrin (HPBC), which may be added to any of the above-described compositions to further improve the aqueous solubility characteristics of the compounds of the present invention. In one embodiment, the composition comprises 0.1% to 20% hydroxypropyl-β-cyclodextrin, more preferably 1% to 15% hydroxypropyl-β-cyclodextrin, and even more preferably from 2.5% to 10% hydroxypropyl-β-cyclodextrin. The amount of solubility enhancer employed will depend on the amount of the compound of the present invention in the composition.
F. Combination Therapy
It is also possible to combine any compound of the present invention with one or more other active ingredients or agents useful in the treatment of cancer, including compounds, in a unitary dosage form, or in separate dosage forms intended for simultaneous or sequential administration to a patient in need of treatment. When administered sequentially, the combination may be administered in two or more administrations. In an alternative embodiment, it is possible to administer one or more compounds of the present invention and one or more additional active ingredients by different routes.
The skilled artisan will recognize that a variety of active ingredients may be administered in combination with the compounds of the present invention that may act to augment or synergistically enhance the VEGF-inhibiting and/or anti-angiogenesis activity of the compounds of the invention.
More specifically, for methods involving the treatment of cancer, agents known in the art to be useful for treating cancer are provided. Such agents include, but are not limited to, radiation therapy, agents that cause DNA damage, agents that reduce the concentration or effect of a growth factor, agents that inhibit angiogenesis, paclitaxel, fluorouracil, CPT-11, a tyrosine kinase inhibitor, a COX-2 inhibitor, thalidomide, gemcitabine, squalamine, endostatin, angiostatin, AE-941, lenalidomide, medi-522, 2-methoxyestradiol, carboxyamidotriazole, combretastatin A4 phosphate, SU6668, SU11248, BMS-275291, COL-3, cilengitide, IMC-1121B, vatalanib, LY317615, VEGF Trap, ZD6474, halofuginone, hydrobromide, celecoxib, interferon alpha, interleukin-12, and antibodies capable of binding VEGF or a VEGF receptor, such as bevacizumab. VEGF receptors include VEGF receptor 1, VEGF receptor 2, and VEGF receptor 3. In another embodiment, the compounds of the present invention are used in combination with an agent that blocks the activity of a VEGF receptor. In yet another embodiment, the compounds of the present invention can be used in combination with agents that can block the VEGF signaling pathway. Treatment only with a factor that can block VEGF signaling may cause an increase in VEGF concentration. In such a case, including a compound of the present invention in the treatment protocol can prevent the subsequent increase in VEGF levels. Similarly, use of the compounds of the present invention in combination with an antibody is highly preferred. Antibodies are relatively large and may not cross tight barriers, allowing secreted VEGF to remain in areas such as the perivascular space. Post-transcriptional control of VEGF expression can prevent the tumor from retaining as much VEGF in the perivascular space, in the extracellular matrix, or in other spaces and vessels that have a physical barrier to antibodies.
According to the methods of the invention, the combination of active ingredients may be: (1) co-formulated and administered or delivered simultaneously in a combined formulation; (2) delivered by alternation or in parallel as separate formulations; or (3) by any other combination therapy regimen known in the art. When delivered in alternation therapy, the methods of the invention may comprise administering or delivering the active ingredients sequentially, e.g., in separate solution, emulsion, suspension, tablets, pills or capsules, or by different injections in separate syringes. In general, during alternation therapy, an effective dosage of each active ingredient is administered sequentially, i.e., serially, whereas in simultaneous therapy, effective dosages of two or more active ingredients are administered together. Various sequences of intermittent combination therapy may also be used.
To assist in understanding the present invention, the following Examples are included. The experiments relating to this invention should not, of course, be construed as specifically limiting the invention and such variations of the invention, now known or later developed, which would be within the purview of one skilled in the art are considered to fall within the scope of the invention as described herein and hereinafter claimed.
The present invention is described in more detail with reference to the following non-limiting examples, which are offered to more fully illustrate the invention, but are not to be construed as limiting the scope thereof. The examples illustrate the preparation of certain compounds of the invention, and the testing of these compounds in vitro and/or in vivo. Those of skill in the art will understand that the techniques described in these examples represent techniques described by the inventors to function well in the practice of the invention, and as such constitute preferred modes for the practice thereof. However, it should be appreciated that those of skill in the art should in light of the present disclosure, appreciate that many changes can be made in the specific methods that are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.
Using the schemes and procedures described above in Section B, one may prepare certain compounds of the invention as follows. Other preferred compounds of the invention, such as those in Table 5 below, may be similarly prepared.
Certain compounds of Formula I may be prepared according to Scheme I using free amine products/intermediates, or their salts prepared in accordance with Procedure I. By way of example, certain free amines (III), or their salts are prepared using Procedure I. Table 4 illustrates certain free amines (III) or their salts, Intermediates 1-11.
Intermediate-1:
This intermediate is prepared using Procedure-I with 5-chlorotryptamine.HCl (5.8 g, 25 mmol), p-anisaldehyde (6.13 mL, 50 mmol) and 0.1N sulfuric acid (60 mL) to give the title compound as an acid salt (6.1 g, 59%). ES-MS: 313 (M+H)+. Alternatively, this intermediate is prepared using Procedure-1B with 5-chlorotryptamine.HCl (20 g, 86.5 mmol), p-anisaldehyde (15.9 mL, 130 mmol) and acetic acid (250 mL) to give the title compound as an acid salt (25.8 g, 79%). ES-MS: 313 (M+H)+.
Intermediate-2:
This intermediate is prepared using Procedure-I with 5-chlorotryptamine.HCl (116 mg, 0.5 mmol), 2,3-difluoro benzaldehyde (109 μL, 1 mmol) and 0.1N sulfuric acid (2 mL) to give the title compound as an acid salt (158 mg, 75%). ES-MS: 319 (M+H)+
Intermediate-3:
This intermediate is prepared using Procedure-I with 5-chlorotryptamine.HCl (462 mg, 2 mmol), 4-chloro benzaldehyde (562 mg, 4 mmol) and 0.1N sulfuric acid (8 mL) to give the title compound as an acid salt (825 mg, 99%). ES-MS: 317 (M+H)+
Intermediate-4:
This intermediate is prepared using Procedure-I with 5-chlorotryptamine.HCl (462 mg, 2 mmol), 4-cyano benzaldehyde (525 mg, 4 mmol) and 0.1N sulfuric acid (8 mL) to give the title compound as an acid salt (810 mg, 100%). ES-MS: 308 (M+H)+
Intermediate-5:
This intermediate is prepared using Procedure-I with 5-chlorotryptamine.HCl (374 mg, 1.5 mmol), 4-fluoro benzaldehyde (322 μL, 3 mmol) and 0.1N sulfuric acid (4 mL) to give the title compound as an acid salt (250 mg, 42%). ES-MS: 301 (M+H)+
Intermediate-6:
This intermediate is prepared using Procedure-I with 5-chlorotryptamine.HCl (1.15 g, 5 mmol), 4-isopropyl benzaldehyde (1.516 mL, 10 mmol) and 0.1N sulfuric acid (12 mL) to give the title compound as an acid salt (628 mg, 30%). ES-MS: 325 (M+H)+
Intermediate-7:
This intermediate is prepared using Procedure-I with 5-bromotryptamine.HCl (551 mg, 2 mmol), 4-chloro benzaldehyde (562 mg, 4 mmol) and 0.1N sulfuric acid (8 mL) to give the title compound as an acid salt (330 mg, 36%). ES-MS: 363 (M+H)+
Intermediate-8:
This intermediate is prepared using Procedure-I with 5-bromotryptamine.HCl (551 mg, 2 mmol), p-tolualdehyde (471 μL, 4 mmol) and 0.1N sulfuric acid (8 mL) to give the title compound as hydrogen sulfate salt (257 mg, 29%). ES-MS: 341 (M+H)+. Alternatively, this intermediate is prepared using Procedure-1B with 5-bromotryptamine.HCl (10 g, 36.3 mmol), p-tolualdehyde (6.41 mL, 54.5 mmol) and acetic acid (120 mL) to give the title compound as acetate salt (14.5 g, 100%). ES-MS: 341 (M+H)+
Intermediate-9 (Compound 112):
This product/intermediate is prepared using Procedure-I with 5-bromotryptamine.HCl (551 mg, 2 mmol), 4-isopropyl benzaldehyde (606 μL, 4 mmol) and 0.1N sulfuric acid (8 mL) to give the title compound as hydrogen sulfate salt (329 mg, 35%). ES-MS: 369 (M+H)+. Alternatively, this intermediate is prepared using Procedure-1B with 5-bromotryptamine.HCl (10 g, 36.3 mmol), 4-isopropyl benzaldehyde (8.24 mL, 54.5 mmol) and acetic acid (120 mL) to give the title compound as acetate salt (13 g, 77%). ES-MS: 369 (M+H)+
Intermediate-10:
This intermediate is prepared using Procedure-I with 5-bromotryptamine.HCl (551 mg, 2 mmol), 3-chloro benzaldehyde (453 μL, 4 mmol) and 0.1N sulfuric acid (8 mL) to give the title compound as an acid salt (662 mg, 72%). ES-MS: 361 (M+H)+
Intermediate-11:
This intermediate is prepared using Procedure-I with 5-bromotryptamine.HCl (551 mg, 2 mmol), p-anisaldehyde (491 μL, 4 mmol) and 0.1N sulfuric acid (8 mL) to give the title compound as an acid salt (611 mg, 67%). ES-MS: 357 (M+H)+
Intermediate-12:
The 4-(2-Morpholin-4-yl-ethoxy)-benzaldehyde reaction intermediate is prepared by combining 4-hydroxybenzaldehyde (1.2 g, 10.0 mmol), 4-(2-chloroethyl)-morpholine hydrochloride (2.0 g, 11.0 mmol), potassium carbonate (4.1 g, 30.0 mmol), and potassium iodide (170 mg, 1 mmol) in 100 ml of acetone and heating to reflux with stirring. After all the 4-hydroxybenzaldehyde is consumed (48 hours by LC/MS), the solids are filtered and the solvent is removed in vacuo. The yield is 4.1 g.
Then Intermediate 12 is prepared in accordance with Procedure-IB. Thus, 5-Chlorotryptamine hydrochloride (231 mg, 1.0 mmol) is combined with 4-(2-Morpholin-4-yl-ethoxy)-benzaldehyde (565 mg, ˜1.2 mmol) in 3 mL of glacial acetic acid. The suspension is heated to about 120° C. for 10 minutes with constant cooling and a max power of 300 W using the CEM Explorer microwave system. Acetonitrile (2 mL) is added to the cooled reaction mixture, and the solid is filtered and washed with 1 mL of acetonitrile to produce the acetic acid salt of Intermediate 12 (6-Chloro-1-[4-(2-morpholin-4-yl-ethoxy)-phenyl]-2,3,4,9-tetrahydro-1H-β-carboline) (179 mg, 34%).
Intermediates 1-12 may then be used to prepare compounds of the invention according to Procedures II through VII as follows.
Compound 2:
This product is prepared by Procedure-II using the Intermediate-1 (3 g, 9.6 mmol), ethyl chloroformate (1.37 mL, 14.4 mmol) and DIEA (2.5 mL, 14.4 mmol) in dichloromethane (70 mL) to give the title compound as white powder (1.56 g, 42%). ES-MS: 385 (M+H)+.
Compound 4:
This product is prepared by Procedure-II using the Intermediate-7 (72 mg, 0.2 mmol), ethyl chloroformate (29 μL, 0.3 mmol) and DIEA (52 μL, 0.3 mmol) in dichloromethane (2 mL) to give the title compound as white powder (37 mg, 43%). ES-MS: 435 (M+H)+.
Compound 5:
This product is prepared by the Procedure-II using the Intermediate-2 (50 mg, 0.16 mmol), ethyl chloroformate (23 μL, 0.24 mmol) and DIEA (42 μL, 0.24 mmol) in dichloromethane (2 mL) to give the title compound as white powder (25 mg, 41%). ES-MS: 391 (M+H)+.
Compound 7:
This product is prepared by the Procedure-II using the Intermediate-9 (74 mg, 0.2 mmol), ethyl chloroformate (29 μL, 0.3 mmol) and DIEA (52 μL, 0.3 mmol) in dichloromethane (2 mL) to give the title compound as white powder (34 mg, 38%). ES-MS: 441 (M+H)+.
Compound 8:
This product is prepared by the Procedure-II using the Intermediate-8 (72 mg, 0.2 mmol), ethyl chloroformate (29 μL, 0.3 mmol) and DIEA (52 μL, 0.3 mmol) in dichloromethane (2 mL) to give the title compound as white powder (39 mg, 47%). ES-MS: 413 (M+H)+.
Compound 10:
This product is prepared by the Procedure-II using the Intermediate-I acetate (10.5 g, 28.2 mmol), 4-chlorophenyl chloroformate (4.74 mL, 33.8 mmol) and DIEA (9.8 mL, 56.4 mmol) in dichloromethane (300 mL) to give the title compound as white powder (10.2 g, 78%). ES-MS: 467 (M+H)+.
Compound 11:
This product is prepared by the Procedure-II using the Intermediate-3 (63 mg, 0.2 mmol), ethyl chloroformate (29 μL, 0.3 mmol) and DIEA (52 μL, 0.3 mmol) in dichloromethane (2 mL) to give the title compound as white powder (31 mg, 40%). ES-MS: 389 (M+H)+.
Compound 12:
This product is prepared by the Procedure-II using the Intermediate-4 (31 mg, 0.1 mmol), 2-chloroethyl chloroformate (16 μL, 0.15 mmol) and DIEA (26 μL, 0.15 mmol) in dichloromethane (2 mL) to give the title compound as white powder (22 mg, 53%). ES-MS: 414 (M+H)+.
Compound 17:
This product is prepared by the Procedure-II using the Intermediate-I (47 mg, 0.15 mmol), 4-methylphenyl chloroformate (33 μL, 0.23 mmol) and DIEA (39 μL, 0.23 mmol) in dichloromethane (2 mL) to give the title compound as white powder (34 mg, 51%). ES-MS: 447 (M+H)+.
Compound 23:
This product is prepared by the Procedure-II using the Intermediate-5 (30 mg, 0.1 mmol), ethyl chloroformate (14 μL, 0.15 mmol) and DIEA (26 μL, 0.15 mmol) in dichloromethane (2 mL) to give the title compound as white powder (21 mg, 56%). ES-MS: 373 (M+H)+.
Compound 25:
This product is prepared by the Procedure-VII using the Intermediate-9 (74 mg, 0.2 mmol), 2-bromopyrimidine (48 mg, 0.3 mmol) and triethylamine (42 μL, 0.3 mmol) in DMF (2 mL) to give the title compound (42 mg, 47%). ES-MS: 447 (M+H)+.
Compound 102:
This product is prepared by the Procedure-IIIb using the Intermediate-9 (74 mg, 0.2 mmol), acetic anhydride (47 μL, 0.5 mmol) and pyridine (41 μL, 0.5 mmol) in dichloromethane (2 mL) to give the title compound as white powder (31 mg, 38%). ES-MS: 411 (M+H)+.
Compound 140:
This product is prepared by the Procedure-IV using the Intermediate-10 (72 mg, 0.2 mmol), cyclohexyl isocyanate (26 μL, 0.2 mmol) and DIEA (37 μL, 0.21 mmol) in dichloromethane (2 mL) to give the title compound as white powder (51 mg, 53%). ES-MS: 486 (M+H)+.
Compound 166:
This product is prepared by the Procedure-IIIa using its free amine intermediate (141 mg, 0.5 mmol), Boc-L-Alanine (105 mg, 0.6 mmol), DIC (94 μL, 0.6 mmol), DIEA (105 μL, 0.6 mmol) and dichloromethane (4 mL) to give the title compound (105 mg, 46%). ES-MS: 420 (M+H)+.
Compound 225:
This product is prepared by the Procedure-VI using its free amine intermediate (78 mg, 0.2 mmol), methyl sulfonylchloride (16 μL, 0.2 mmol) and DIEA (37 μL, 0.21 mmol) and dichloromethane (2 mL) to give the title compound (32 mg, 34%). ES-MS: 461 (M+H)+.
Compound 242:
This product is prepared by the Procedure-V using its free amine intermediate (59 mg, 0.2 mmol), cyclohexyl isothiocyanate (29 μL, 0.2 mmol), DIEA (35 μL, 0.2 mmol) and dichloromethane (4 mL) to give the title compound (52 mg, 60%). ES-MS: 438 (M+H)+.
Compound 279:
This product is prepared by generating Intermediate 12 (6-Chloro-1-[4-(2-morpholin-4-yl-ethoxy)-phenyl]-2,3,4,9-tetrahydro-1H-β-carboline) using Procedure-I. Intermediate 12 is then used to generate Compound 279 (6-Chloro-1-[4-(2-morpholin-4-yl-ethoxy)-phenyl]-1,3,4,9-tetrahydro-b-carboline-2-carboxylic acid ethyl ester) using Procedure-II.
In accordance with Procedure-II, Intermediate 12 (82 mg, 0.20 mmol), ethyl chloroformate (24 mg, 21 μL, 0.22 mmol), and diisopropylethylamine (175 μL, 1.00 mmol) are dissolved in methylene chloride (2 mL) and stirred at room temperature for 15 minutes to form Compound 279. The solvent is removed under a stream of nitrogen. The crude mixture is purified by preparative reversed phase HPLC on a C-18 column using a gradient of acetonitrile in water buffered with 0.2% trifluoroacetic acid (TFA). The TFA salt of Compound 279 (3.7 mg, 3%) is isolated as a yellow solid. The same procedure may be applied for other carbamate formation reactions according to Procedure-II.
Compound 320:
This product/intermediate is prepared using Procedure-I with 5-benzyloxy tryptamine.HCl (100 mg, 0.33 mmol), pyridine-3-carboxaldehyde (62 μL, 0.66 mmol) and 0.1N sulfuric acid (2 mL) to give the title compound as dihydrogen sulfate salt (64 mg, 55%). ES-MS: 356 (M+H)+
Compound 329:
This product is prepared by the Procedure-VII using the Intermediate-11 (71 mg, 0.2 mmol), 2-bromopyrimidine (48 mg, 0.3 mmol) and triethylamine (42 μL, 0.3 mmol) in DMF (2 mL) to give the title compound (41 mg, 49%). ES-MS: 434 (M+H)+.
Compound 330:
This product is prepared by the Procedure-II using the Intermediate-6 (65 mg, 0.2 mmol), 2-fluoroethyl chloroformate (38 μL, 0.3 mmol) and DIEA (70 μL, 0.4 mmol) in dichloromethane (2 mL) to give the title compound as white powder (34 mg, 41%). ES-MS: 415 (M+H)+.
Compound 332:
This product is prepared by the Procedure-II using the Intermediate-7 (36 mg, 0.1 mmol), 4-methoxyphenyl chloroformate (22 μL, 0.15 mmol) and DIEA (26 μL, 0.15 mmol) in dichloromethane (2 mL) to give the title compound as white powder (41 mg, 81%). ES-MS: 511 (M+H)+.
Scheme Ia can be used when in conjunction with Scheme I (above) to generate starting materials when R2 is a —CH2-furanyl group, as follows.
2-furaldehyde (0.05 mL, 1.1 eq) is added to a solution of 5-chlorotryptamine (114 mg, 0.586 mmol) in 2 mL of MeOH. The reaction mixture is stirred at room temperature for about 1 hour. NaBH4 (110 mg, 5 eq) is added slowly. The reaction mixture is stirred at room temperature for about 30 min. MeOH is evaporated and the residue is partitioned between water and methylene chloride. The organic layer is separated and dried over K2CO3. The collected organic layer is concentrated to give 134.9 mg of viscous oil (84%).
Alternatively, certain compounds of Formula I may be prepared according to Scheme Ib as follows.
A suspension of reaction material A (8.05 g, 35.9 mmol) and CH3COONH4 (4.15 g, 1.5 eq) in 60 mL of CH3NO2 is refluxed in oil bath at about 110° C. After about 30 minutes, the reaction mixture is cooled with ice-bath. The precipitated solid is filtered and washed with water (3×100 mL), followed by hexane (2×50 mL) to give crude indole product B. The collected solid is dried under vacuum at about 40° C. for about 30 min to give 6.97 g of brown solid (73%).
A solution of indole product B (12.32 g, 46.1 mmol) in THF (130 mL) is then treated with a solution of tetrabutylammonium borohydride (11.9 g, 1 eq) in 75 mL of THF slowly for about 60 minutes at about −5° C. The reaction is stirred at room temperature for about 1 hour and diluted with dichloromethane (200 mL). The organic layer is washed with water twice and brine. The combined organic layers are dried and evaporated under vacuum. The residue is purified on silica gel to give 10.28 g of solid C (83%).
Ammonium chloride (9.9 mL of aqueous solution (100 mg/mL), 2 eq) and Zn (725 mg, 1.2 eq) are then added to a solution of indole product C (2.49 g, 9.24 mmol) in 161 mL of THF. The reaction mixture is stirred at room temperature for about 10 min and Zn (725 mg, 1.2 eq) is then added. After about 30 min, additional Zn (967 mg, 1.6 eq) is added and stirred for about 2 hours, followed by the addition of further Zn (845 mg, 1.4 eq). After stirring at room temperature for about 15 min, Zn is filtered off and the residue is concentrated and dissolved in THF. The resulting solution is then treated with p-chlorobenzaldehyde (0.7 eq) and stirred at room temperature for about 15 hours. The reaction mixture is concentrated under vacuum and purified on silica gel to give 953.5 mg of the desired nitrone product D.
(+)-DIP-Cl (6.93 mL, 2 eq, 85.8 mg/mL in CH2Cl2) is then added to a solution of nitrone product D (350 mg, 0.93 mmol) in 60 mL of dichloromethane. The reaction mixture is stirred at about −78° C. for about 10 days and quenched with a mixture of 10% NaHCO3 (7 mL) and 10 mL of water. The aqueous layer is extracted with dichloromethane three times. Combined organic layers are concentrated and purified on silica gel to give the desired hydroxylamine product E (>98% ee).
Water (11.5 mL), NH4Cl (2.5 mL, 5 eq) and Zn (908 mg, 15 eq) are then added to a solution of hydroxylamine product E (0.927 mmol) in THF (28 mL). The reaction mixture is stirred at room temperature for about 1 day. Additional THF (10 mL), NH4Cl (5 mL, 10 eq) and Zn (1.8 g, 30 eq) are then added and stirred for about another 21 hours. Again, THF (10 mL), NH4Cl (5 mL, 10 eq) and Zn (1.8 g, 30 eq) are added and stirred for about another 20 hours. The reaction mixture is then filtered through celite and washed with MC. The collected dichloromethane layer is washed with water and brine. The organic layer is dried and concentrated to give a boron complex of beta-carboline. This product is dissolved in 20 mL of THF. This solution is loaded into prepacked cation exchange resin (preconditioned with MeOH and THF) and washed with THF. The combined THF solution is concentrated to give 390 mg of free amine. The solid is then washed with ether and hexane consecutively to yield 130 mg of the enantiomerically pure compound F.
Compounds of Formula I-h may be prepared according to Scheme II as follows.
p-anisaldehyde (2.16 g, 15.9 mmol, 1.93 mL) is added to a suspension of 5-Bromotryptophan A (3 g, 10.6 mmol) in 100 mL of Acetic acid at room temperature. The reaction mixture is then heated to reflux at about 125° C. in silicon oil bath and maintained at that temperature for about 3 hours 20 minutes. The resultant solution is concentrated under vacuum. The residue is triturated with dichloromethane, diethyl ether and hexane to yield a powdery brown solid. The acetic salts of the intermediate product B is collected and washed with hexane three times.
The intermediate product B is suspended (70 mg, 0.174 mmol) in 2 mL of dichloromethane, and triethylamine (52.8 mg, 0.522 mmol), 5-methyl-2-aminothiazole (37.6 mg, 0.26 mmol) and PyBOP (135.8 mg, 0.26 mmol) is added to the suspension. The reaction mixture is stirred at room temperature for about 6 hour and quenched with sat. NaHCO3 solution. The aqueous layer is extracted with dichloromethane. The combined organic layers are dried over K2CO3 and concentrated. Purification on silica gel with 40% ethyl acetate in hexane yields 8.1 mg of the desired amide C. LCMS [MH+] 498, Rt=2.54.
Compounds of Formula I-i may be prepared according to Scheme III as follows.
Tryptophan A (1.0 g, 5.0 mmol) and 3-methoxybenzaldehyde (670 μL, 5.5 mmol) are suspended/dissolved in acetonitrile (100 mL) and concentrated sulfuric acid (100 μL) is added. The reaction is heated to reflux until all the aldehyde was consumed (overnight). The solvent was removed in vacuo and the residue was dissolved in 5 mL of ethanol. The product was precipitated out with ether, filtered, and washed with 10 mL of ether. The desired β-carboline product/intermediate B (1-(3-Methoxy-phenyl)-2,3,4,9-tetrahydro-1H-β-carboline-3-carboxylic acid) is isolated as a beige solid (1.2 g, 76%). LC/MS RT=2.33 min. M/Z+323, 100%.
The β-carboline product/intermediate B (200 mg, 0.62 mmol) is then dissolved in 5 mL of dry THF and cooled to about 0° C. Lithium aluminum hydride (LAH) solution (1.2 mL, 1.0M in ether, 1.2 mmol) is added to the cooled reaction mixture under nitrogen. After the addition is complete (about 10 minutes), the reaction is allowed to warm to room temperature for about 4 hours. The reaction mixture is then cooled back to 0° C., and saturated sodium sulfate solution (750 μL) is added and the mixture stirred for about 5 minutes at 0° C. The reaction mixture is then filtered and washed with THF (100 mL). The solvent is removed in vacuo, and the crude product purified by preparative HPLC. The product C ([1-(3-Methoxy-phenyl)-2,3,4,9-tetrahydro-1H-b-carbolin-3-yl]-methanol) is isolated as a white solid (106 mg, 55%). LC/MS RT=2.25 min. M/Z+309, 100%.
Compounds of the invention may optionally be chemical resolved to enantiomerically pure compositions, preferably enantiomerically pure (S) isomer compositions as follows.
The racemic amine A (18.21 g, 58.2 mmol) is mixed with N-acetyl-L-phenylalanine (12.05 g, 58.2 mmol) in EtOH (1.28 L) and refluxed to get a clear solution. The solution is then allowed to cool to room temperature. After overnight standing, the precipitated solid is filtered and washed with EtOH (200 mL) to give the salt B (16.4 g). The salt B is taken in EtOAc (500 mL) and washed with aqueous 1N NaOH (300 mL×2) or NH4OH (200 mL×2), dried and evaporated to give the S-isomer of the free amine C (7.4 g). The R-isomer is prepared by similar procedure using N-acetyl-D-phenylalanine.
By way of further non-limiting example, the following compounds (Table 5) may be prepared by similar methodology to that described above, as will be recognized by one of skill in the art.
The ability of the compounds of the invention to modulate hypoxia-inducible endogenous VEGF expression may be analyzed as follows. VEGF protein levels may be monitored by an ELISA assay (R&D Systems). Briefly, HeLa cells may be cultured for 24-48 hours under hypoxic conditions (1% O2, 5% CO2, balanced with nitrogen) in the presence or absence of a compound of the invention. The conditioned media may then be assayed by ELISA, and the concentration of VEGF calculated from the standard ELISA curve of each assay.
A dose-response analysis may be performed using the ELISA assay and conditions described above. The conditions for the dose-response ELISA are analogous to those described above. A series of, e.g., seven different concentrations may be analyzed. In parallel, a dose-response cytotoxicity assay may be performed using Cell Titer Glo (Promega) under the same conditions as the ELISA to ensure that the inhibition of VEGF expression was not due to the cytotoxicity. Dose-response curves may be plotted using percentage inhibition versus concentration of the compound, and EC50 and CC50 values may be generated for each compound with the maximal inhibition set as 100% and the minimal inhibition as 0%.
Preferred compounds of the invention will have an EC50 of less than 50, preferably less than 10, more preferably less than 2, even more preferably less than 0.5, and even more preferably less than 0.01.
# (S) Isomer prepared and tested.
Wherein:
1 star, >1 uM (1000 nM)
2 stars, 0.2 to 1 uM (200 nM to 1000 nM)
3 stars, 0.04 uM to 0.2 uM (40 nM to 200 nM)
4 stars, 0.008 uM to 0.04 uM (8 nM to 40 nM)
5 stars, <0.008 uM (<8 nM)
Compounds of the invention also show activity in the following pharmacodynamic model that assesses tumor VEGF levels. Briefly, HT1080 cells (a human fibrosarcoma cell line) may be implanted subcutaneously in nude mice. After seven days, mice may be administrated compounds orally at a desired dosage range, e.g., 200 mg/kg/day, for seven days. The tumors may then be excised from mice, weighed and homogenized in Tris-HCl buffer containing proteinase inhibitors. Moulder et al., Cancer Res. 61(24):8887-95 (2001). Tumor VEGF levels are subsequently measured using a human VEGF ELISA kit (R&D System). Protein concentrations of the homogenates are measured with a Bio-Rad Protein assay kit and tumor VEGF levels are normalized to the protein concentrations.
Preferred compounds of the invention, when used for one week on a 100 mm3 tumor, will generally inhibit tumor growth by at least 50%, as compared to the vehicle-treated control groups. In similarly conducted experiments, compounds of the invention are shown to reduce lung cancer tumor growth (at a dosage of 3 mg/kg, twice a day, or 30 mg/kg, twice a day) (
The tumors excised from the mice can also be used in immunochemistry experiments to determine levels of angiogenesis. As seen in
Human solid tumor cells are treated with various concentrations of a compound of the present invention or a control under hypoxic conditions. Actinomycin D blocks transcription and is used as a control. Total RNA is isolated using the RNeasy kit (Qiagen, Inc., Valencia, Calif., USA) or an acid-guanidinium thiocyanate-phenol-chloroform based method (See Chomczynski, P. and Sacchi, N., Anal. Biochem. 162: 156 (1987), hereby incorporated by reference).
Concentration of total RNA can be determined using the RiboGreen® fluorescent dye (Molecular Probes, Inc., Eugene, Oreg., USA) with the VersaFluor Fluorometer System (BioRad, Hercules, Calif., USA). Quality and integrity of total RNA can be assessed on 1% formaldehyde-agarose gels. First-strand cDNA was synthesized using 1 μg of total RNA (DNase-treated) in a 20 μl reverse transcriptase reaction mixture (Leclerc G J, Barredo J C, Clin. Cancer Res. 2001, 7:942-951, which is hereby incorporated by reference). A region of the VEGF mRNA is amplified using PCR primers. The cDNA amplified fragment (approximately 300 basepairs) is cloned into a vector such as the pCR2.1-TOPO vector (Invitrogen, Carlsbad, Calif., USA) to generate a plasmid. Serial ten-fold dilutions (104 to 109 molecules) of this plasmid are used as a reference molecule for standard curve calculation. All Real-Time PCR reactions are performed in a 25 μl mixture containing 1/20 volume of cDNA preparation (1 μl), 1×SYBR Green buffer (PE Applied Biosystems, Foster City, Calif., USA), 4 mM MgCl2, 0.2 μM of each VEGF primer used above, 0.2 mM dNTPs mix and 0.025 Unit of AmpliTaq Gold® thermostable DNA polymerase (Applied Biosystems, Foster City, Calif., USA). Real-Time quantitations are performed using the BIO-RAD iCycler iQ system (BioRad, Hercules, Calif., USA). The fluorescence threshold value can be calculated using the iCycle iQ system software. Using similar methodologies, the data shown in
The compounds of the invention are tested to assess their affect on phosphodiesterase 5 (PDE5) activity. The affect on PDE5 activity is determined using the High-Efficiency Fluorescence Polarization Assay (HEFP) kit from Molecular Devices. The HEFP assay measures the activity of PDE-5 by using fluorescein-labeled derivatives of cGMP as a substrate. When hydrolyzed by PDE-5, fluorescein-labeled cGMP derivatives are able to bind to a binding reagent. The cGMP substrate:binding reagent complex results in a highly polarized fluorescent state.
All publications and patent applications cited herein are incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
Although certain embodiments have been described in detail above, those having ordinary skill in the art will clearly understand that many modifications are possible in the embodiments without departing from the teachings thereof. All such modifications are intended to be encompassed within the claims of the invention.
This application is a continuation-in-part of U.S. application Ser. No. 11/079,420, filed Mar. 15, 2005, and having the title “Carboline Derivatives Useful in the Inhibition of Angiogenesis,” which claims the benefit of and priority to U.S. Provisional Application No. 60/552,725, filed Mar. 15, 2004, which applications are incorporated herein by reference. This application also claims priority to International Application No. (application number to be assigned), filed Mar. 15, 2005, and having the title “Carboline Derivatives Useful in the Inhibition of Angiogenesis,” which application is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 60552725 | Mar 2004 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11079420 | Mar 2005 | US |
| Child | 11107783 | Apr 2005 | US |
