- Development and pre-clinical testing of a novel hypoxia-activated KDAC inhibitor
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Tumor hypoxia is associated with therapy resistance and poor patient prognosis. Hypoxia-activated prodrugs, designed to selectively target hypoxic cells while sparing normal tissue, represent a promising treatment strategy. We report the pre-clinical efficacy of 1-methyl-2-nitroimidazole panobinostat (NI-Pano, CH-03), a novel bioreductive version of the clinically used lysine deacetylase inhibitor, panobinostat. NI-Pano was stable in normoxic (21% O2) conditions and underwent NADPH-CYP-mediated enzymatic bioreduction to release panobinostat in hypoxia (2). Treatment of cells grown in both 2D and 3D with NI-Pano increased acetylation of histone H3 at lysine 9, induced apoptosis, and decreased clonogenic survival. Importantly, NI-Pano exhibited growth delay effects as a single agent in tumor xenografts. Pharmacokinetic analysis confirmed the presence of sub-micromolar concentrations of panobinostat in hypoxic mouse xenografts, but not in circulating plasma or kidneys. Together, our pre-clinical results provide a strong mechanistic rationale for the clinical development of NI-Pano for selective targeting of hypoxic tumors.
- Skwarska, Anna,Calder, Ewen D.D.,Sneddon, Deborah,Bolland, Hannah,Odyniec, Maria L.,Mistry, Ishna N.,Martin, Jennifer,Folkes, Lisa K.,Conway, Stuart J.,Hammond, Ester M.
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p. 1258 - 13,1270
(2021/09/16)
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- Hypoxia-activated pro-drugs of the KDAC inhibitor vorinostat (SAHA)
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Hypoxia (lower than normal oxygen) is a characteristic of most solid tumours that results in poor cancer patient prognosis. The difference in cellular environment between normoxia (21percent oxygen) or physoxia (4–7.5percent oxygen) and hypoxia (2.0percent oxygen) causes increased resistance to radio- and chemotherapy, but also provides the opportunity to selectively release hypoxia-activated pro-drugs. This approach potentially allows targeting of chemotherapies, including lysine deacetylase (KDAC) inhibitors, to the hypoxic fraction of cells. Here, we report initial work on the development of KDAC inhibitors that are selectively released in hypoxic conditions. We have shown that the addition of a 4-nitrobenzyl (NB) or 1-methyl-2-nitroimidazole (NI) bioreductive group onto the hydroxamic acid moiety of SAHA, giving NB-SAHA and NI-SAHA, abolishes KDAC inhibition activity. Both NB-SAHA and NI-SAHA undergo enzyme-mediated bioreduction, in a hypoxia-dependent manner, to release SAHA selectively in 0.1percent oxygen. This work provides an important foundation for further investigations into the targeted release of KDAC inhibitors in hypoxic tumours.
- Calder, Ewen D. D.,Conway, Stuart J.,Folkes, Lisa K.,Hammond, Ester M.,Mistry, Ishna N.,Skwarska, Anna,Sneddon, Deborah
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- Preparation method of evofosfamide
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The invention relates to a synthetic method for preparing evofosfamide, namely N,N'-bis(2-bromoethyl)diaminophosphonic acid (1-methyl-2-nitro-1H-imidazol-5-yl)methyl ester (I), and belongs to the field of organic synthesis. The synthetic method has the advantages of safe and stable route, convenient operation, easy purification, high yield and the like.
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Paragraph 0039; 0050-0055
(2020/02/20)
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- Compositions and methods for treating cancer
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The invention provides a protected anti-neoplastic agent of the formula Hyp-N, wherein N is an anti-neoplastic agent and a protectable hydroxyl group of the anti-neoplastic is substituted with Hyp; Hyp is a moiety having the formula: wherein R 2 is hydrogen; R 3 is hydrogen or C 1 -C 6 alkyl; R 1 is C 1 -C 6 alkyl or C 1 -C 6 alkoxy, optionally substituted with one or more heteroatom-containing groups; and R 4 is hydrogen, C 1 -C 6 alkyl, or C 1 -C 6 alkoxy, optionally substituted with one or more heteroatom-containing groups.
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Paragraph 0021-00214
(2019/10/16)
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- Structure-activity relationship study of hypoxia-activated prodrugs for proteoglycan-targeted chemotherapy in chondrosarcoma
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Due to an abundant chondrogenic, poorly vascularized and particularly hypoxic extracellular matrix, chondrosarcoma, a malignant cartilaginous tumour, is chemo- and radio-resistant. Surgical resection with wide margins remains the mainstay of treatment. To address the lack of therapy, our strategy aims to increase anticancer drugs targeting and delivery in the tumour, by leveraging specific chondrosarcoma hallmarks: an extensive cartilaginous extracellular matrix, namely the high negative fixed charge density and severe chronic hypoxia. A dual targeted therapy for chondrosarcoma was investigated by conjugation of a hypoxia-activated prodrug (HAP) to quaternary ammonium (QA) functions which exhibit a high affinity for polyanionic sites of proteoglycans (PGs), the major components of the chondrosarcoma extracellular matrix. Based on preclinical results, an imidazole prodrug, ICF05016, was identified and provided the basis for a lead optimization study. A series of 27 QA-phosphoramide mustard conjugates, differing by the type of QA function and the length of the alkyl linker, was yielded by a common multi-step sequence involving phosphorylation of a key 2-nitroimidazole alcohol. Then, a screening was realized by surface plasmon resonance technology to assess biomolecular interactions between QA derivatives and aggrecan, the most abundant PG in chondrosarcoma. Results revealed that affinity depends more on the type of QA function, than on the linker length. Moreover, the presence of a benzyl group enhanced affinity to aggrecan. Twelve compounds were shortlisted and evaluated for antiproliferative activity (i.e., growth inhibiting concentration 50), under normoxic and hypoxic conditions using the human extraskeletal myeloid chondrosarcoma cell line (HEMC-SS). For all prodrugs, hypoxic selectivity was maintained and even increased, compared with the lead. From this study, compound 31f emerged as the most effective PG-targeted HAPs with a dissociation constant of 2.10 μM in the SPR experiment, a hypoxia cytotoxicity ratio of 24 and an efficient reductive cleavage under chemical and enzymatic conditions.
- Ghedira, Donia,Voissière, Aurélien,Peyrode, Caroline,Kraiem, Jamil,Gerard, Yvain,Maubert, Elise,Vivier, Magali,Miot-Noirault, Elisabeth,Chezal, Jean-Michel,Farhat, Farhat,Weber, Valérie
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- Bioreductively activatable prodrug conjugates of phenstatin designed to target tumor hypoxia
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A variety of solid tumor cancers contain significant regions of hypoxia, which provide unique challenges for targeting by potent anticancer agents. Bioreductively activatable prodrug conjugates (BAPCs) represent a promising strategy for therapeutic intervention. BAPCs are designed to be biologically inert until they come into contact with low oxygen tension, at which point reductase enzyme mediated cleavage releases the parent anticancer agent in a tumor-specific manner. Phenstatin is a potent inhibitor of tubulin polymerization, mimicking the chemical structure and biological activity of the natural product combretastatin A-4. Synthetic approaches have been established for nitrobenzyl, nitroimidazole, nitrofuranyl, and nitrothienyl prodrugs of phenstatin incorporating nor-methyl, mono-methyl, and gem-dimethyl variants of the attached nitro compounds. A series of BAPCs based on phenstatin have been prepared by chemical synthesis and evaluated against the tubulin-microtubule protein system. In a preliminary study using anaerobic conditions, the gem-dimethyl nitrothiophene and gem-dimethyl nitrofuran analogues were shown to undergo efficient enzymatic cleavage in the presence of NADPH cytochrome P450 oxidoreductase. Each of the eleven BAPCs evaluated in this study demonstrated significantly reduced inhibitory activity against tubulin in comparison to the parent anti-cancer agent phenstatin (IC50?=?1.0?μM). In fact, the majority of the BAPCs (seven of the eleven analogues) were not inhibitors of tubulin polymerization (IC50?>?20?μM), which represents an anticipated (and desirable) attribute for these prodrugs, since they are intended to be biologically inactive prior to enzyme-mediated cleavage to release phenstatin.
- Winn, Blake A.,Shi, Zhe,Carlson, Graham J.,Wang, Yifan,Nguyen, Benson L.,Kelly, Evan M.,Ross, R. David,Hamel, Ernest,Chaplin, David J.,Trawick, Mary L.,Pinney, Kevin G.
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p. 636 - 641
(2017/01/17)
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- Synthesis and biological evaluation of hypoxia-activated prodrugs of SN-38
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We designed new hypoxia-activated prodrugs by conjugating (1-methyl-2-nitro-1H-imidazol-5-yl)methanol with 7-ethyl-10-hydroxy camptothecin (SN-38). Initially, we improved the method of multi-gram scale synthesis of (1-methyl-2-nitro-1H-imidazol-5-yl)methanol, which increased the yield to 42% compared to 8% by the original synthesis method. The improved method was used to synthesize evofosfamide (TH-302) and hypoxia-activated prodrugs of SN-38. Two different linkages between (1-methyl-2-nitro-1H-imidazol-5-yl)methanol and SN-38 were evaluated that afforded different hypoxia-selectivity and toxicity. Compound 16 (IOS), containing an ether linkage, was considered to be a promising hypoxia-selective antitumor agent.
- Jin, Chen,Zhang, Qiumeng,Lu, Wei
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p. 135 - 141
(2017/03/29)
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- Targeting a Targeted Drug: An Approach Toward Hypoxia-Activatable Tyrosine Kinase Inhibitor Prodrugs
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Tyrosine kinase inhibitors (TKIs), which have revolutionized cancer therapy over the past 15 years, are limited in their clinical application due to serious side effects. Therefore, we converted two approved TKIs (sunitinib and erlotinib) into 2-nitroimidazole-based hypoxia-activatable prodrugs. Kinetics studies showed very different stabilities over 24 h; however, fast reductive activation via E. coli nitroreductase could be confirmed for both panels. The anticancer activity and signaling inhibition of the compounds against various human cancer cell lines were evaluated in cell culture. These data, together with molecular docking simulations, revealed distinct differences in the impact of structural modifications on drug binding to the enzymes: whereas the catalytic pocket of the epidermal growth factor receptor (EGFR) accepted all new erlotinib derivatives, the vascular endothelial growth factor receptor (VEGFR)-inhibitory potential in the case of the sunitinib prodrugs was dramatically diminished by derivatization. In line, hypoxia dependency of ERK signaling inhibition was observed with the sunitinib prodrugs, while oxygen levels had no impact on the activity of the erlotinib derivatives. Overall, proof of principle could be shown for this concept, and the results obtained are an important basis for the future development of tyrosine kinase inhibitor prodrugs.
- Karnthaler-Benbakka, Claudia,Groza, Diana,Koblmüller, Bettina,Terenzi, Alessio,Holste, Katharina,Haider, Melanie,Baier, Dina,Berger, Walter,Heffeter, Petra,Kowol, Christian R.,Keppler, Bernhard K.
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p. 2410 - 2421
(2016/11/13)
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- TH-302 SOLID FORMS AND METHODS RELATED THERETO
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The present invention provides a new method for making TH-302 and solid forms thereof. The compound in its solid form is an effective anti-cancer agent and may be used in various pharmaceutical compositions, and are particularly effective for the treatment of cancer. The invention also provides a method for preparing such compounds and forms and for treating cancer in a mammal comprising the step of administering a therapeutically effective amount of a solid form of TH-302 thereof.
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Paragraph 0053; 0101
(2016/02/10)
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- PHOSPHORAMIDATE ALKYLATOR PRODRUGS
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Phosphoramidate alkylator prodrugs can be used to treat cancer when administered alone or in combination with one or more anti-neoplastic agents.
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Page/Page column 143
(2008/06/13)
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- Design, synthesis and evaluation of imidazolylmethyl carbamate prodrugs of alkylating agents
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Two approaches to prodrugs of alkylating agents based on an imidazolylmethyl carbamate nucleus were explored. A 2-azido analogue (3) of the bis-carbamate carmethizole (1) displayed similar aerobic cytotoxicity to 1 in a panel of human and murine cell lines. Approaches to the 2-amino and 2- carbamoyl analogues are described. In the second approach an imidazolylmethanol was used as a 'trigger' linked via a carbamate to the alkylating agent N,N-bis(2-chlorethyl)amine (BCEA). Nitroimidazole and methylsulphinylimidazole carbamate prodrugs 6-8 were 5-20-fold less toxic than BCEA. Despite this deactivation in the prodrug form, little increase in cytotoxicity was observed under hypoxia. The data suggest that BCEA released on bioreduction is not sufficiently potent to contribute significant additional cytotoxicity. (C) 2000 Elsevier Science Ltd.
- Hay, Michael P.,Wilson, William R.,Denny, William A.
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p. 645 - 657
(2007/10/03)
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- A 2-nitroimidazole carbamate prodrug of 5-amino-1(chloromethyl)-3- [(5,6,7-trimethoxyindol-2-yl)carbonyl]-1,2-dihydro-3H-benz[e]indole (amino- seco-CBI-TMI) for use with ADEPT and GDEPT
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The synthesis of a 2-nitroimidazol-5-ylmethyl carbamate prodrug 10 of the potent minor groove alkylating agent amino-seco-CBI-TMI 3 is described. Chemical, radiolytic, and enzymic reductions of a model 2-nitroimidazol-5-yl carbamate 8 show release of the amine effector upon reduction. Prodrug 10 gives a ten fold increase in cytotoxicity against human ovarian carcinoma SKOV3 cells in the presence of E. coli B nitroreductase (NTR) and a 21-fold increase in cytotoxicity against a SKOV3 cell line (SC3.2) transfected with the gene for NTR. The cytotoxicity of 10 increased 15- to 40-fold under hypoxia. Prodrug 10 has significant potential as a prodrug for use in ADEPT and GDEPT applications, and as a hypoxia-selective cytotoxin.
- Hay, Michael P.,Sykes, Bridget M.,Denny, William A.,Wilson, William R.
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p. 2237 - 2242
(2007/10/03)
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- 2-Nitroimidazol-5-ylmethyl as a potential bioreductively activated prodrug system: Reductively triggered release of the parp inhibitor 5- bromoisoquinolinone
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5-Chloromethyl-1-methyl-2-nitroimidazole reacted efficiently with the anion derived from 5-bromoisoquinolin-1-one to give 5-bromo-2-((1-methyl-2- nitroimidazol-5-yl)methyl)isoquinolin-1-one. Biomimetic reduction effected release of the 5-bromoisoquinolin-1-one. The 2-nitroimidazol-5-ylmethyl unit thus has potential for development as a general prodrug system for selective drug delivery to hypoxic tissues.
- Parveen, Ifat,Naughton, Declan P.,Whish, William J. D.,Threadgill, Michael D.
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p. 2031 - 2036
(2007/10/03)
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- 2-Nitroimidazole derivatives
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2-Nitroimidazole derivatives of the general formula SPC1 Wherein R is a lower alkyl group and Y is a member of the group consisting of --CH2 OH, --CHO, CH3 CO--, vinyl, formylvinyl, styryl, substituted iminomethyl, 2-benzimidazolyl and 5-amino-1,3,4-thiadiazol-2-yl. The term "lower alkyl" designates aliphatic groups of from 1 to 4 carbon atoms; the term "substituted iminomethyl" designates nitrogen-containing functional derivatives of the aldehydic group. The compounds have antimicrobial activity.
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