Tuesday, 31 December 2013


Maropitant, is described in WO1992021677, US 6,222,038 and US
6,255,230,US 5340826, US 5393762, EP 0769300, WO 2000073304, WO 2005082419, WO 2005082366


  • Cerenia
  • CJ-11,972
  • Maropitant citrate
  • UNII-LXN6S3999X
Maropitant (trade name Cerenia in the US and other countries), used as maropitantcitrate (USAN), is a neurokinin (NK1) receptor antagonist, which was developed by Zoetisspecifically for the treatment of motion sickness and vomiting in dogs. It was approved by the FDA in 2007 for use in dogs,[1][2] and more recently has also been approved for use in cats.[3]

Use of the cryopreserved human hepatocyte sandwich-culture model to measure hepatic metabolism and biliary efflux
1st Int Conf Drug Des Disc (February 4-7, Dubai) 2008, Abst P-140

Proposed international nonproprietary names (Prop. INN): List 90
WHO Drug Inf 2004, 18(1): 56

Maropitant, a NK-1 antagonist decreases the sevoflurane MAC during visceral stimulation in dogs
13th World Congr Pain (August 29-September 2, Montreal) 2010, Abst PW 320

Identification of metabolites from maropitant using a dual-pressure linear ion trap and mass frontier software
9th Int ISSX Meet (September 4-8, Istanbul) 2010, Abst P343

Effect of maropitant, a new NK-1 receptor antagonist, on the sevoflurane minimum alveolar concentration during ovarian stimulation in cats
Annu Meet Am Soc Anesthesiol (ASA) (October 15-19, Chicago) 2011, Abst A1585

US81832305-23-2012Antimicrobial preservatives to achieve multi-dose formulation using beta-cyclodextrins for liquid dosage forms
US20090993644-17-2009Process for preparation of 1-(2s,3s)-2-benzhydryl-n-(5- tert-butyl-2-methoxybenzyl)quinuclidin-3-amine
US20071557827-6-2007Nk-1 receptor antagonists anesthesia recovery
US20071293286-8-2007Pharmaceutical compositions of neurokinin receptor antagonists and cyclodextrin and methods for improved injection site toleration
US20031394437-25-2003Use of tachykinin antagonists, including NK-1 receptor antagonists, to modify unwanted behavior in dogs, cats and horses
US62553207-4-2001Polymorphs of a crystalline azo-bicyclo (2,2,2) octan-3-amine citrate and their pharmaceutical compositions
US599012511-24-1999NK-1 receptor antagonists for the treatment of cancer
US557631711-20-1996NK-1 receptor antagonists and 5HT3 receptor antagonists for the treatment of
US55190335-22-1996Azabicyclo derivatives for treatment of urinary incontinence
US53937622-29-1995Pharmaceutical agents for treatment of emesis
US53408268-24-1994Pharmaceutical agents for treatment of urinary incontinence

anhydrous (2S,3S)-N-(methoxy-5-t-butylphenylmethyl-2-diphenylmethyl-1-azobicyclo[2,2,2] octan-3-amine citrate monohydrate salt, its single crystalline polymorphic Form A, and pharmaceutical composition containing them. The invention is also directed to a CNS active NK-1 receptor antagonist for treating emesis in a mammal including humans. Treating is defined here as preventing and treating.
Figure US06255320-20010703-C00001

U.S. Pat. No. 5,393,762 and U.S. Ser. No. 08/816,016, both incorporated by reference, describe pharmaceutical compositions and treatment of emesis using NK-1 receptor antagonists. The citrate monohydrate has significantly enhanced stability over other salt forms such as the benzoate which was unstable even at 5° C. The mesylate form is deliquescent.
U.S. 5,807,867, U.S. 6,222,038 and U.S. 6,255,320.
Figure US20090099364A1-20090416-C00001

The compound of Formula I, an NK1 receptor antagonist, is effective as an anti-emetic agent for mammals. The compound of Formula I is the subject of U.S. Pat. No. 6,222,038 and U.S. Pat. No. 6,255,320, and the preparation of the compound of Formula I is described therein. U.S. Pat. No. 5,393,762 also describes pharmaceutical compositions and treatment of emesis using NK-1 receptor antagonists. The multiple-use formulation of the compound of Formula I may be parenterally administrated for about five days at the same site for treatment of emesis or other indications. Intravenous or, preferably, subcutaneous administration is desirable for acute use, since retention and absorption of an oral dosage form may be problematic during bouts of emesis. The multiple-use formulation is described in a co-pending U.S. provisional application No. 60/540,897 assigned to and owned by Pfizer. Inc.
The compound of Formula I also improves anesthesia recovery in mammals. A co-pending U.S. provisional application No. 60/540,697 assigned to and owned by Pfizer Inc., describes a method of improving anesthesia recovery by administering a NK-1 antagonist prior to, during or after the administration of general anesthesia.

Figure US20090099364A1-20090416-C00026
Figure US20090099364A1-20090416-C00027

Figure US20090099364A1-20090416-C00028

Preparation of (2S,3S)-2-benzhydryl-N-(5-tert-butyl-2-methoxybenzyl) quinuclidin-3-amine citrate monohydrate, Compound of Formula Ia Step C, Scheme II
A solution of (2S,3S)-2-benzhydryl-N-(tert-butyl-2-methoxybenzyl) quinuclidin-3-amine (33.95 kg, 72.4 moles) and anhydrous citric acid (15.3 kg, 79.7 moles) in a mixture of acetone (215 kg) and water (13.6 kg) was heated to 38-42° C. The resultant mixture was then transferred to another reactor via an in-line filter. The transfer line and filter were washed through with acetone (54 kg) and these filtered washings were added to the solution. The resultant mixture was then cooled to 20-25° C. and filtered fart-butyl methyl ether (252 kg) was added portion-wise over a period of approximately 35 minutes. The resultant suspension was then granulated at 20-25° C. for approximately 20 hours. The solid was then collected by filtration on an agitated filter-dryer and the filter cake was washed twice with filtered tert-butyl methyl ether (50 kg each). The resultant solid was then dried at 35° C. under vacuum with agitation to give the title compound (44.4 kg) as a colourless solid. The product was then milted.
1H-NMR (500 MHz, d6-methanol, 30° C.) δ: 7.46 (2H, d), 7.45 (2H, d), 7.37 (4H, m), 7.31 (1H, m), 7.29 (1H, m), 7.24 (1H, dd), 6.95 (1H, d), 6.76 (1H, d), 4.75 (1H, dd), 4.71 (1H, d), 3.76 (1H, m), 3.57 (1H, d), 3.55 (3H, s), 3.37 (1H, m), 3.31 (1H, m), 3.26 (1H, m), 3.24 (1H, d), 3.10 (1H, t), 2.83 (2H, d), 2.75 (2H, d), 2.51 (1H, m), 2.35 (1H, m), 2.11 (1H, m), 2.06 (1H, m), 1.85 (1H, m), 1.29 (9H, s).

13C NMR (125.7 MHz, d6-methanol, 30° C.) δ: 179.4, 175.0, 156.8, 144.0, 141.5, 141.4, 131.1, 130.6, 129.4, 128.9, 128.7, 128.3, 128.2, 127.2, 126.4, 111.0, 74.0, 64.7, 56.1, 54.2, 50.4, 48.5, 48.3, 44.9, 43.8, 34.8, 32.9, 25.3, 22.2, 18.1.
LRMS (ES+): m/z [MH+] 469.

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Monday, 30 December 2013


OSI 906
CAS:  867160-71-2
Chemical Formula: C26H23N5O
Molecular Weight: 421.5
Elemental Analysis: C, 74.09; H, 5.50; N, 16.62; O, 3.80
Linsitinib (OSI-906) is  an orally bioavailable small molecule inhibitor of the insulin-like growth factor 1 receptor (IGF-1R) with potential antineoplastic activity.  OSI-906 selectively inhibits IGF-1R, which may result in the inhibition of tumor cell proliferation and the induction of tumor cell apoptosis. Overexpressed in a variety of human cancers, IGFR-1 stimulates cell proliferation, enables oncogenic transformation, and suppresses apoptosis
Linsitinib (OSI-906) was developed through drug-discovery efforts focused on identifying a potent and selective, small-molecule inhibitor of the IGF-1R signaling axis. The lead optimization phase utilized IR and IGF-1R co-crystal structures, with lead compounds from the imidazopyrazine series, to afford a structure-based design-driven component, which complemented ongoing empirical medicinal chemistry efforts. These combined approaches improved metabolic and pharmacokinetic liabilities of earlier lead compounds and ultimately led to the discovery of OSI-906. OSI-906 was synthesized from an advanced imidazopyrazine intermediate in two linear steps. OSI-906 potently inhibits ligand-dependent auto-phosphorylation of both human IGF-1R and IR in cells, while displaying a high degree of selectivity versus a wide panel of protein kinases.
Moreover, OSI-906, through its inhibition of both IGF-1R and IR, prevents ligand-induced activation of downstream pathways including pAKT, pERK1/2 and p-p70S6K and, therefore, inhibits proliferation in a variety of tumor cell lines. Robust anti-tumor activity was achieved in an IGF-1R-driven LISN xenograft model following once-daily oral administration of OSI-906. The anti-tumor activity obtained in this study correlated well with the degree and duration of inhibition of tumor IGF-1R phosphorylation achieved in vivo by OSI-906. OSI-906 is a novel, potent, selective and orally bioavailable dual IGF-1R/IR kinase inhibitor with demonstrated in vivo efficacy in tumor models. It is currently being evaluated in clinical trials.
Furthermore, the exceptional selectivity profile of OSI-906 in conjunction with its ability to inhibit both IGF-1R and IR provides the unique opportunity to fully target the IGF-1R/IR axis. (source: Future Medicinal Chemistry September 2009, Vol. 1, No. 6, Pages 1153-1171. )
Linsitinib is an experimental drug candidate for the treatment of various types of cancer. It is an inhibitor of the insulin receptor and of the insulin-like growth factor 1 receptor (IGF-1R).[1] This prevents tumor cell proliferation and induces tumor cell apoptosis.[2]
The development of target-based anti-cancer therapies has become the focus of a large number of pharmaceutical research and development programs. Various strategies of intervention include targeting protein tyrosine kinases, including receptor tyrosine kinases believed to drive or mediate tumor growth.
Insulin-like growth factor-1 receptor (IGF-1R) is a receptor tyrosine kinase that plays a key role in tumor cell proliferation and apoptosis inhibition, and has become an attractive cancer therapy target. IGF-1R is involved in the establishment and maintenance of cellular transformation, is frequently overexpressed by human tumors, and activation or overexpression thereof mediates aspects of the malignant phenotype. IGF-1R activation increases invasion and metastasis propensity.
Inhibition of receptor activation has been an attractive method having the potential to block IGF-mediated signal transduction. Anti-IGF-1R antibodies to block the extracellular ligand-binding portion of the receptor and small molecules to target the enzyme activity of the tyrosine kinase domain have been developed. See Expert Opin. Ther. Patents, 17(1):25-35 (2007); Expert Opin. Ther. Targets, 12(5):589-603 (2008); and Am J. Transl. Res., 1:101-114 (2009).
US 2006/0235031 (published Oct. 19, 2006) describes a class of bicyclic ring substituted protein kinase inhibitors, including Example 31 thereof, which corresponds to the dual IR/IGF-1R inhibitor known as OSI-906. As of 2011, OSI-906 is in clinical development in various cancers and tumor types. The preparation and characterization of OSI-906, which can be named as cis-3-[8-amino-1-(2-phenyl-quinolin-7-yl)-imidazo[1,5-a]pyrazin-3-yl]-1-methylcyclobutanol, is described in the aforementioned US 2006/0235031.
OSI-906 is a potent, selective, and orally bioavailable dual IGF-1R/IR kinase inhibitor with favorable drug-like properties. The selectivity profile of OSI-906 in conjunction with its ability to inhibit both IGF-1R and IR affords the special opportunity to fully target the IGF-1R/IR axis. See Future Med. Chem., 1(6), 1153-1171, (2009).
It is desirable to develop novel processes to prepare imidazopyrazine compounds, namely OSI-906, which may be practical, economical, efficient, reproducible, large scale, and meet regulatory requirements.
Linsitinib was discovered by OSI Pharmaceuticals and is currently in Phase III clinical trials for adrenocortical carcinoma and Phase II clinical trials for lung and ovarian cancers.[3][4]

  1.  Mulvihill, MJ; Cooke, A; Rosenfeld-Franklin, M; Buck, E; Foreman, K; Landfair, D; O’Connor, M; Pirritt, C et al. (2009). “Discovery of OSI-906: A selective and orally efficacious dual inhibitor of the IGF-1 receptor and insulin receptor”. Future medicinal chemistry 1 (6): 1153–71. doi:10.4155/fmc.09.89.PMID 21425998.
  2.  “Linsitinib”NCI Drug DictionaryNational Cancer Institute. Retrieved October 16, 2012.
  3.  “OSI Pharmaceuticals, LLC”Astellas Pharma. Retrieved October 16, 2012.
  4.  “Linsitinib”. National Institutes of Health’s clinicaltrials.gov. Retrieved October 16, 2012.
OSI-906: A novel, potent, and selective first-in-class small molecule insulin-like growth factor 1 receptor (IGF-1R) inhibitor in phase I clinical trials
238th ACS Natl Meet (August 16-20, Washington) 2009, Abst MEDI 152
cis-3-[8-amino-1-(2-phenyl-quinolin-7-yl)-imidazo[1,5-a]pyrazin-3-yl]-1-methylcyclobutanol (OSI-906) (Compound 1)

Figure US20130123501A1-20130516-C00022

A vessel was charged with DMF (79 kg), cis-3-(8-amino-1-bromo-imidazo[1,5-a]pyrazin-3-yl)-1-methylcyclobutanol (16.725 kg), 2-phenyl-7-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-quinoline (22.4 kg), triphenylphosphine (0.586 kg), cesium carbonate (36.7 kg) and water (20.1 kg). The reaction mixture was degassed and heated to 95-105° C. and a solution of palladium acetate (0.125 kg) in DMF (9.8 kg) was added and rinsed in with DMF (5.9 kg). After the reaction was complete, water (154 kg) was added keeping the temperature above 70° C. The resultant slurry was cooled and the solid was collected by filtration. After washing with a mixture of DMF (9.4 kg) and water (23.4 kg) and then water (67 kg) the solid was suspended in water (167 kg) at 50° C. and the pH of the mixture was adjusted to 2.9 with 6N hydrochloric acid (10.9 kg). The resultant yellow slurry was filtered to remove the major impurities and the cake was washed with water (67 kg). The acid solution was stirred at 50-55° C. and polymer bound trimercaptotriazine resin (MP-TMT) (4.9 kg) was added. The mixture was stirred for 23 hours, the resin was removed by filtration and the cake was washed with water (58 kg).
The resultant acid solution was diluted with 2-propanol (82 kg), the temperature was adjusted to 35-45° C. and the pH was adjusted to 5.0 by the addition of 1N sodium hydroxide solution. The mixture was cooled, the yellow product was collected by filtration and was washed with water (33 kg). The solid was re-suspended in water (157 kg) stirred, filtered and washed with water (125 kg). The solid was dried under vacuum at 45-55° C. (the resulting material was a hemihydrate of OSI-906 designated Form C) and was then stirred in refluxing 2-propanol (157 kg) for 3 hours. The mixture was cooled and the solid was isolated by filtration. After washing with 2-propanol (26.7 kg), the product was dried at 45-55° C. under vacuum to yield 15.6 kg (65% yield) of OSI-906. The resulting material was an anhydrous crystalline form of OSI-906 designated Form A.
Example 2cis-3-(1-bromo-8-chloro-imidazo[1,5-a]pyrazin-3-yl)-1-methylcyclobutanol

Figure US20130123501A1-20130516-C00023

THF (87 kg) and 3M methyl magnesium chloride (83.6 kg) were charged to a vessel. The contents were cooled to −65 to −55° C. and 3-(1-bromo-8-chloro-imidazo[1,5-a]pyrazin-3-yl)-cyclobutanone (33.0 kg) in THF (253 kg) was added, maintaining the temperature at −65° C. to −45° C.
The charged vessel was rinsed with THF (41 kg) and the reaction mixture was stirred at −65 to −45° C. until reaction completion. Preferably, the level of iron present in the reaction is about 100 ppm or less, or about 20 ppm or less. These conditions are suitable to achieve the desired stereoselectivity. A 5% ammonium chloride solution (462 kg) was added slowly while maintaining the temperature below 10° C. The aqueous layer was then separated, the pH was adjusted to pH 7-8 by the addition of 6N hydrochloric acid and the mixture was extracted with methyl t-butyl ether (2×145 kg). The combined organic extracts were washed sequentially with 1N sodium hydroxide solution (330 kg) and 20% sodium chloride solution (2×330 kg). THF (767 kg) was then added and the solution was distilled to a residual volume of 165 L. Toluene (567 kg) was added and again the mixture was distilled to a volume of 165 L. The mixture was heated to 85-90° C. until complete dissolution was achieved and then cooled to 20-30° C. to crystallize the product. The solids were collected by filtration, washed with toluene (2×41 kg) and dried at 50-60° C. under vacuum. Yield was 78%. 1H NMR (300 MHz, DMSO-d6) δ 8.3 (d, 1H), 7.4 (d, 1H), 5.2 (s, 1H), 3.5 (m, 1H), 2.4 (m, 4H), 1.4 (s, 3H).
Example 3cis-3-(8-amino-1-bromo-imidazo[1,5-a]pyrazin-3-yl)-1-methylcyclobutanol

Figure US20130123501A1-20130516-C00024

Cis-3-(1-bromo-8-chloro-imidazo[1,5-a]pyrazin-3-yl)-1-methylcyclobutanol (27.1 kg), isopropanol (65 kg) and 30% ammonia solution (165 kg) were charged to a suitable vessel. The vessel was sealed and the mixture was heated and stirred for 18 hours at 75 to 85° C. and then cooled. The vessel was vented to a scrubber and water (22 kg) was added. The mixture was concentrated under vacuum to a residual volume of 73-89 L and was then cooled to <5° C. The product was collected by filtration and washed with water (2×108 kg). The product was dried at 40-50° C. under vacuum. Yield was 88%. 1H NMR (300 MHz, DMSO-d6) δ 7.5 (d, 1H), 7.0 (d, 1H), 6.6 (br s, 2H), 5.2 (s, 1H), 3.4 (m, 1H), 2.4 (m, 4H), 1.4 (s, 3H).
Example 4cis-8-amino-3-(3-hydroxy-3-methyl-cyclobutyl)-1-(2-phenyl-quinolin-7-yl)-imidazo[1,5-a]pyrazin-7-ium chloride

Figure US20130123501A1-20130516-C00025

This material was prepared by heating OSI-906 with an equivalent of hydrochloric acid in water and then allowing the solution to cool. The solid was filtered from the cooled mixture and dried. The XRPD and DSC suggest a semi-crystalline material. The DSC, XRPD, and 1H NMR (300 MHz, DMSO-d6) of the sample were recorded and are reproduced in FIGS. 1, 2, and 3, respectively.
WO 2010107968
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The present invention provides for methods of preparing OSI-906 Forms A-G illustrated in Scheme 1 .

Figure imgf000021_0001
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SAR-302503; TG-101348
1. Benzenesulfonamide, N-(1,1-dimethylethyl)-3-[[5-methyl-2-[[4-[2-(1-
2. N-tert-butyl-3-[(5-methyl-2-{4-[2-(pyrrolidin-1-yl)ethoxy]anilino}pyrimidin-4-
CAS REGISTRY NUMBER……….936091-26-8

WHO 9707

TG-101348 , a dual-acting JAK2/FLT3 small molecule kinase inhibitor, has been evaluated in phase III clinical development at Sanofi (formerly known as sanofi-aventis) for the oral treatment of intermediate-2 or high risk primary myelofibrosis, post-polycythemia vera myelofibrosis or post-essential thrombocythemia myelofibrosis with splenomegaly. However, development of the compound has been discontinued due to safety issues.
In preclinical models of myeloproliferative diseases, TG-101348, administered orally, was shown to reduce V617F-expressing cell populations in a dose-dependent manner without adversely impacting normal hematopoiesis. The reduction of V617F- expressing cell populations correlated with improved survival and reduced morbidity. Orphan drug designation was assigned in the U.S. and in Japan for the treatment of secondary and primary myelofibrosis. In July 2010, TargeGen was acquired by Sanofi. In 2013, orphan drug designation was assigned by the FDA for the treatment of polycythemia vera.
WO 2013059548
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US 2007259904
WO 2007053452

Treliński J, Robak T.
Curr Med Chem. 2013;20(9):1147-61.

Santos FP, Verstovsek S.
Anticancer Agents Med Chem. 2012 Nov;12(9):1098-109. Review.
Looi CY, Imanishi M, Takaki S, Sato M, Chiba N, Sasahara Y, Futaki S, Tsuchiya S, Kumaki S.
PLoS One. 2011;6(8):e23640. doi: 10.1371/journal.pone.0023640. Epub 2011 Aug 10
Example 90 N-tert-Butyl-3-{5-methyl-2-[4-(2-pyrrolidin-1-yl-ethoxy)-phenylamino]-pyrimidin-4-ylamino}-benzenesulfonamide (Compound LVII)

Figure US20070191405A1-20070816-C00156

A mixture of intermediate 33 (0.10 g, 0.28 mmol) and 4-(2-pyrrolidin-1-yl-ethoxy)-phenylamine (0.10 g, 0.49 mmol) in acetic acid (3 mL) was sealed in a microwave reaction tube and irradiated with microwave at 150° C. for 20 min. After cooling to room temperature, the cap was removed and the mixture concentrated. The residue was purified by HPLC and the corrected fractions combined and poured into saturated NaHCOsolution (30 mL). The combined aqueous layers were extracted with EtOAc (2×30 mL) and the combined organic layers washed with brine, dried over anhydrous Na2SOand filtered. The filtrate was concentrated and the resulting solid dissolved in minimum amount of EtOAc and hexanes added until solid precipitated. After filtration, the title compound was obtained as a white solid (40 mg, 27%).
1H NMR (500 MHz, DMSO-d6): δ 1.12 (s, 9H), 1.65-1.70 (m, 4H), 2.12 (s, 3H), 2.45-2.55 (m, 4H), 2.76 (t, J=5.8 Hz, 2H), 3.99 (t, J=6.0 Hz, 2H), 6.79 (d, J=9.0 Hz, 2H), 7.46-7.53 (m, 4H), 7.56 (s, 1H), 7.90 (s, 1H), 8.10-8.15 (m, 2H), 8.53 (s, 1H), 8.77 (s, 1H). MS (ES+): m/z 525 (M+H)+.

Example 76 N-tert-Butyl-3-(2-chloro-5-methyl-pyrimidin-4-ylamino)-benzenesulfonamide (Intermediate 33)

Figure US20070191405A1-20070816-C00142

A mixture of 2-chloro-5-methyl-pyrimidin-4-ylamine (0.4 g, 2.8 mmol), 3-bromo-N-tert-butyl-benzenesulfonamide (1.0 g, 3.4 mmol), Pd2(dba)(0.17 g, 0.19 mmol), Xantphos (0.2 g, 3.5 mmol) and cesium carbonate (2.0 g, 6.1 mmol) was suspended in dioxane (25 mL) and heated at reflux under the argon atmosphere for 3 h. The reaction mixture was cooled to room temperature and diluted with DCM (30 mL). The mixture was filtered and the filtrate concentrated in vacuo. The residue was dissolved in EtOAc and hexanes added until solid precipitated. After filtration, the title compound (1.2 g, 98%) was obtained as a light brown solid. It was used in the next step without purification. MS (ES+): m/z 355 (M+H)+.

Sunday, 29 December 2013



Treatment of anemia

Roxadustat nonproprietary drug name


1. Glycine, N-[(4-hydroxy-1-methyl-7-phenoxy-3-isoquinolinyl)carbonyl]-

2. N-[(4-hydroxy-1-methyl-7-phenoxyisoquinolin-3-yl)carbonyl]glycine

FG-4592 (also known as ASP1517), 2-(4-hydroxy-1-methyl-7-phenoxyisoquinoline-3-carboxamido)acetic acid,
 is a potent small molecule inhibitor of hypoxia-inducible factor prolyl hydroxylase (HIF-PH),
an enzyme up-regulating the expression of endogenous human erythropoietin (Epo).
It is currently being investigated as an oral treatment for anemia associated with chronic kidney disease (CKD). 
Unlike other anemia treating agents, erythropoiesis-stimulating agents (ESAs), 
FG-4592 inhibits HIF, through a distinctive mechanism, by stabilization of HIF. According to previous studies, 
FG-4592 is capable of correcting and maintaining hemoglobin levels in CKD patients not
receiving dialysis and in patients of end-stage renal disease 
who receives dialysis but do not need intravenous iron supplement.
1. Luis Borges. Different modalities of erythropoiesis stimulating agents.
 Port J Nephrol Hypert 2010; 24(2): 137-145
2. “FibroGen and Astellas announce initiation of phase 3 trial of FG-4592/ASP1517 for treatment 
of anemia of chronic kidney disease” Fibrogen Press Release. Dec 11 2012
3. “FibroGen announces initiation of phase 2b studies of FG-4592, 
an oral HIF prolyl hydroxylase inhibitor, for treatment of anemia”

synthesis will be updated
WO 2004108681
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SAN FRANCISCO, Nov 12, 2013 (BUSINESS WIRE) -- FibroGen, Inc. (FibroGen), today announced that data from a China-based Phase 2 study of roxadustat (FG-4592), a first-in-class oral compound in late stage development for the treatment of anemia associated with chronic kidney disease (CKD) and end-stage renal disease (ESRD), were presented in an oral session at the 2013 American Society of Nephrology (ASN) Kidney Week in Atlanta, Georgia.
Roxadustat is an orally administered, small molecule inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase. HIF is a protein that responds to oxygen changes in the cellular environment and meets the body's demands for oxygen by inducing erythropoiesis, the process by which red blood cells are produced and iron is incorporated into hemoglobin (Hb).
The randomized, double-blind, placebo-controlled study was designed to evaluate the efficacy, safety, and tolerability of roxadustat in the correction of anemia in patients (N=91) with chronic kidney disease who had not received dialysis treatment, were not receiving erythropoiesis-stimulating agents (ESAs), and had Hb levels less than 10 g/dL. The correction study randomized patients 2:1 between roxadustat and placebo for 8 weeks of dosing, and included a low-dose cohort (n=30) and high-dose cohort (n=31). Intravenous (IV) iron was not allowed. The study also evaluated iron utilization, changes in serum lipids, and other biomarkers during treatment with roxadustat.
Data from this study suggest that roxadustat effectively corrected hemoglobin levels in anemic CKD patients in a dose-dependent manner as compared to placebo, and did so in the absence of IV iron supplementation regardless of degree of iron repletion at baseline. At the end of the 8-week treatment period, subjects showed mean maximum Hb increases from baseline of 2.6 g/dL in the high dose cohort and 1.8 g/dL in the low dose cohort, as compared to 0.7 g/dL in the placebo group (p < 0.0001) from mean baseline Hb of 8.8 g/dL, 8.8 g/dL, and 8.9 g/dL in the high dose, low dose, and placebo groups, respectively. 87% of patients in the high-dose cohort, 80% of patients in the low-dose cohort, and 23% of patients in the placebo group experienced a hemoglobin increase of 1 g/dL or greater from baseline (p < 0.0001). Similarly, 71% of patients in the high-dose cohort, 50% of patients in the low-dose cohort, and 3% of patients in the placebo group achieved target hemoglobin of 11 g/dL or greater (p < 0.0001). Serum iron levels remained stable in subjects randomized to roxadustat while the subjects underwent brisk erythropoiesis.
Study data also suggest that roxadustat may lower cholesterol. Dyslipidemia is highly prevalent in chronic kidney disease patients and a major cardiovascular risk factor in this population. Patients treated with roxadustat experienced a statistically significant reduction in total cholesterol (p <0.0001) and low-density lipoprotein (LDL) cholesterol (p <0.0001) at the end of the treatment period. The relative proportion of high density lipoprotein (HDL) cholesterol to LDL cholesterol increased significantly (p <0.02). Overall LDL cholesterol levels declined by a mean of 26% and median of 23% from a mean baseline value of 103 mg/dL.
Roxadustat was well tolerated by patients in the study with incidence of adverse events similar across all groups. In contrast to the exacerbation of hypertension observed in studies in which patients received currently available ESA therapies, subjects who received roxadustat in the present study showed small decreases in blood pressure that were similar to blood pressure changes in the placebo group. No cardiovascular serious adverse events were reported in patients treated with roxadustat.
The efficacy and safety of roxadustat are currently being investigated in a global pivotal Phase 3 development program.
"There is a global need for effective, safe, and accessible anemia therapies," said Thomas B. Neff, Chief Executive Officer of FibroGen. "Side effects associated with current treatments include exposure to supra-physiological levels of erythropoietin and depletion of iron stores. Preliminary clinical findings show that oral administration of roxadustat (FG-4592) is able to correct anemia and maintain hemoglobin levels in patients with chronic kidney disease, to do so with peak erythropoietin levels within physiological range, and to achieve these effects without the administration of intravenous iron. These results suggest roxadustat, as an oral agent, has the potential to overcome the treatment barriers and inconveniences of current ESA therapies, including administration by injection and IV iron supplementation, in treating anemia in CKD patients."
About Chronic Kidney Disease (CKD) and Anemia
Diabetes, high blood pressure, and other conditions can cause significant damage to the kidneys. If left untreated, those can result in chronic kidney disease and progress to kidney failure. Such deterioration can lead to patients needing a kidney transplant or being placed on dialysis to remove excess fluid and toxins that build up in the body. The progression of CKD also increases the prevalence of anemia, a condition associated with having fewer of the red blood cells that carry oxygen through the body, and/or lower levels of hemoglobin, the protein that enables red blood cells to carry oxygen. As hemoglobin falls, the lower oxygen-carrying capacity of an anemic patients' blood results in various symptoms including fatigue, loss of energy, breathlessness, and angina. Anemia in CKD patients has been associated with increased hospitalization rates, increased mortality, and reduced quality of life.
Chronic kidney disease is a worldwide critical healthcare problem that affects millions of people and drives significant healthcare cost. In the US, prevalence of CKD has increased dramatically in the past 20 years, from 10 percent of the adult population (or approximately 20 million U.S. adults) as stated in the National Health and Nutrition Evaluation Survey (NHANES) 1988-1994, to 15 percent (or approximately 30 million U.S. adults) in NHANES 2003-2006. In 2009, total Medicare costs for CKD patients were $34 billion. China has an estimated 145 million CKD patients, or approximately five times the number of CKD patients in the U.S. (Lancet April 2012).
About Roxadustat / FG-4592
Roxadustat (FG-4592) is an orally administered small molecule inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase activity, in development for the treatment of anemia in patients with chronic kidney disease (CKD). HIF is a protein transcription factor that induces the natural physiological response to conditions of low oxygen, "turning on" erythropoiesis (the process by which red blood cells are produced) and other protective pathways. Roxadustat has been shown to correct anemia and maintain hemoglobin levels without the need for supplementation with intravenous iron in CKD patients not yet receiving dialysis and in end-stage renal disease patients receiving dialysis. An Independent Data Monitoring Committee has found no signals or trends to date to suggest that treatment with roxadustat is associated with increased risk of cardiovascular events, thrombosis, or increases in blood pressure requiring initiation or intensification of antihypertensive medications.
About FibroGen
FibroGen is a privately-held biotechnology company focused on the discovery, development, and commercialization of therapeutic agents for treatment of fibrosis, anemia, cancer, and other serious unmet medical needs. FibroGen's FG-3019 monoclonal antibody is in clinical development for treatment of idiopathic pulmonary fibrosis and other proliferative diseases, including pancreatic cancer and liver fibrosis. Roxadustat (FG-4592), FibroGen's small molecule inhibitor of hypoxia-inducible factor (HIF) prolyl hydroxylase, is currently in clinical development for the treatment of anemia. FibroGen is also currently pursuing the use of proprietary recombinant human type III collagens in synthetic corneas for treatment of corneal blindness. For more information please visit: www.fibrogen.com .