Conatus’s liver drug emricasan gets FDA orphan drug status

254750-02-2 cas no

emricasan

PF 03491390, IDN 6556

pfizer

Prevention of fibrosis and inflammation in chronic liver disease

The compound had been studied in phase II clinical trials for the treatment of liver transplant rejection and hepatitis B

(3S)-3-[[(2S)-2-[[2-[(2-tert-butylphenyl)amino]-2-oxoacetyl]amino]propanoyl]amino]-4-oxo-5-(2,3,5,6-tetrafluorophenoxy)pentanoic acid, C26 H27 F4 N3 O7, 569.5

http://www.ama-assn.org/resources/doc/usan/emricasan.pdf

Conatus’s liver drug emricasan gets FDA orphan drug status
US-based biotechnology firm Conatus Pharmaceuticals has received orphan drug designation from the US Food and Drug Administration (FDA) for its drug candidate emricasan to treat liver transplant recipients with re-established fibrosis to delay the progression to cirrhosis and end-stage liver disease.http://www.pharmaceutical-technology.com/news/newsconatuss-chronic-liver-disease-treatment-emricasan-gets-fda-orphan-drug-status-4139697?WT.mc_id=DN_News

 

Emricasan, also known as IDN 6556 and  PF 03491390, is a first-in-class caspase inhibitor in clinical trials for the treatment of liver diseases. IDN-6556 has marked efficacy in models of liver disease after oral administration and thus, is an excellent candidate for the treatment of liver diseases characterized by excessive apoptosis. IDN-6556 appears to be a feasible therapeutic agent against ischemia-reperfusion injury in liver transplantation.

WO 2002057298

WO 2000001666

Interleukin 1 (“IL-1”) is a major pro-inflammatory and immunoregulatory protein that stimulates fibroblast differentiation and proliferation, the production of prostaglandins, collagenase and phospholipase by synovial cells and chondrocytes, basophil and eosinophil degranulation and neutrophil activation. Oppenheim, J.H. et al.. Immunology Today, 7:45-56 (1986). As such, it is involved in the pathogenesis of chronic and acute inflammatory and autoimmune diseases. IL-1 is predominantly produced by peripheral blood monocytes as part of the inflammatory response. Mosely, B.S. et al.. Proc. Nat. Acad. Sci.. 84:4572-4576 (1987); Lonnemann, G. et al. Eur. J. Immunol., 19:1531-1536 (1989).

IL-lβ is synthesized as a biologically inactive precursor, proIL-lβ. ProIL-lβ is cleaved by a cysteine protease called interleukin-lβ converting enzyme (“ICE”) between Asp-116 and Ala-117 to produce the biologically active C-terminal fragment found in human serum and synovial fluid. Sleath, P.R. et al., J. Biol. Chem., 265:14526-14528 (1992); A.D. Howard et al, J. Immunol., 147:2964-2969 (1991).

ICE is a cysteine protease localized primarily in monocytes. In addition to promoting the pro -inflammatory and immunoregulatory properties of IL-lβ, ICE, and particularly its homologues, also appear to be involved in the regulation of cell death or apoptosis. Yuan, J. et al„ Cell, 75:641-652 (1993); Miura, M. et al. Cell, 75:653-660 (1993); Nett-Giordalisi, M.A. et al, J. Cell Biochem., 17B:117 (1993). In particular, ICE or ICE/ced-3 homologues are thought to be associated with the regulation of apoptosis in neurogenerative diseases, such as Alzheimer’s and Parkinson’s disease. Marx, J. and M. Baringa, Science, 259:760-762 (1993); Gagliardini, N et al„ Science, 263:826-828 (1994).

Thus, disease states in which inhibitors of the ICE/ced-3 family of cysteine proteases may be useful as therapeutic agents include: infectious diseases, such as meningitis and salpingitis; septic shock, respiratory diseases; inflammatory conditions, such as arthritis, cholangitis, colitis, encephalitis, endocerolitis, hepatitis, pancreatitis and reperfusion injury, ischemic diseases such as the myocardial infarction, stroke and ischemic kidney disease; immune-based diseases, such as hypersensitivity; auto-immune diseases, such as multiple sclerosis; bone diseases; and certain neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease. Such inhibitors are also useful for the repopulation of hematopoietic cells following chemo- and radiation therapy and for prolonging organ viability for use in transplantation.

ICE/ced-3 inhibitors represent a class of compounds useful for the control of the above-listed disease states. Peptide and peptidyl inhibitors of ICE have been described. However, such inhibitors have been typically characterized by undesirable pharmacologic properties, such as poor oral absorption, poor stability and rapid metabolism. Plattner, J.J. and D.W. Norbeck, in Drug Discovery Technologies, C.R. Clark and W.H. Moos, Eds. (Ellis Horwood, Chichester, England, 1990), pp. 92-126. These undesirable properties have hampered their development into effective drugs.

Accordingly, the need exists for compounds that can effectively inhibit the action of the ICE/ced-3 family of proteases, for use as agents for preventing unwanted apoptosis, and for treating chronic and acute forms of IL-1 mediated diseases such as inflammatory, autoimmune or neurodegenerative diseases. The present invention satisfies this need and provides further related advantages.

References

1: McCall M, Toso C, Emamaullee J, Pawlick R, Edgar R, Davis J, Maciver A, Kin T, Arch R, Shapiro AM. The caspase inhibitor IDN-6556 (PF3491390) improves marginal mass engraftment after islet transplantation in mice. Surgery. 2011 Jul;150(1):48-55. doi: 10.1016/j.surg.2011.02.023. Epub 2011 May 18. PubMed PMID: 21596412.

2: Pockros PJ, Schiff ER, Shiffman ML, McHutchison JG, Gish RG, Afdhal NH, Makhviladze M, Huyghe M, Hecht D, Oltersdorf T, Shapiro DA. Oral IDN-6556, an antiapoptotic caspase inhibitor, may lower aminotransferase activity in patients with chronic hepatitis C. Hepatology. 2007 Aug;46(2):324-9. PubMed PMID: 17654603.

3: Hoglen NC, Anselmo DM, Katori M, Kaldas M, Shen XD, Valentino KL, Lassman C, Busuttil RW, Kupiec-Weglinski JW, Farmer DG. A caspase inhibitor, IDN-6556, ameliorates early hepatic injury in an ex vivo rat model of warm and cold ischemia. Liver Transpl. 2007 Mar;13(3):361-6. PubMed PMID: 17318854.

4: Baskin-Bey ES, Washburn K, Feng S, Oltersdorf T, Shapiro D, Huyghe M, Burgart L, Garrity-Park M, van Vilsteren FG, Oliver LK, Rosen CB, Gores GJ. Clinical Trial of the Pan-Caspase Inhibitor, IDN-6556, in Human Liver Preservation Injury. Am J Transplant. 2007 Jan;7(1):218-25. PubMed PMID: 17227570.

5: Poordad FF. IDN-6556 Idun Pharmaceuticals Inc. Curr Opin Investig Drugs. 2004 Nov;5(11):1198-204. Review. PubMed PMID: 15573871.

6: Hoglen NC, Chen LS, Fisher CD, Hirakawa BP, Groessl T, Contreras PC. Characterization of IDN-6556 (3-[2-(2-tert-butyl-phenylaminooxalyl)-amino]-propionylamino]-4-oxo-5-(2,3,5,6-te trafluoro-phenoxy)-pentanoic acid): a liver-targeted caspase inhibitor. J Pharmacol Exp Ther. 2004 May;309(2):634-40. Epub 2004 Jan 23. PubMed PMID: 14742742.

7: Valentino KL, Gutierrez M, Sanchez R, Winship MJ, Shapiro DA. First clinical trial of a novel caspase inhibitor: anti-apoptotic caspase inhibitor, IDN-6556, improves liver enzymes. Int J Clin Pharmacol Ther. 2003 Oct;41(10):441-9. PubMed PMID: 14703949.

8: Canbay A, Feldstein A, Baskin-Bey E, Bronk SF, Gores GJ. The caspase inhibitor IDN-6556 attenuates hepatic injury and fibrosis in the bile duct ligated mouse. J Pharmacol Exp Ther. 2004 Mar;308(3):1191-6. Epub 2003 Nov 14. PubMed PMID: 14617689.

9: Natori S, Higuchi H, Contreras P, Gores GJ. The caspase inhibitor IDN-6556 prevents caspase activation and apoptosis in sinusoidal endothelial cells during liver preservation injury. Liver Transpl. 2003 Mar;9(3):278-84. PubMed PMID: 12619025.

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WO2002057298A2

 

http://www.google.com/patents/WO2002057298A2

EXAMPLE 126

 

(3 S)-3 – [N-(N’-(2-TERT-BUTYLPHENYL)OXAMYL) ALANINYL] AMINO-5-(2′,3′,5′,6′-TETRAFLUOROPHENOXY)-4-OXOPENTANOIC ACID

Part A: [(N-Benzyloxycarbonyl Alaninyl]Aspartic Acid, β-tert-Butyl Ester

To a suspension of aspartic acid β-tert-butyl ester (3.784 g, 20 mmol) in dimethylformamide (150 mL) at room temperture under nitrogen was added bis(trimethylsilyl)-trifluoroacetamide (10.6 mL, 40 mmol). After stirring at room temperature for 30 min, the resulting clear solution was treated with (N- benzyloxycarbonyl)alanine N-hydroxysuccinimide ester (6.406 g, 20 mmol). After stirring at room temperature for an additional 48 hrs, the mixture was treated with water (20 mL), stirred for 15 min and then partitioned between EtO Ac/water. The organic phase was washed with water, 5% KHSO and saturated NaCl solutions, dried over anhydrous Na₂SO and evaporated to a dryness. The residue was dissolved in Et₂O and extracted with saturated NaHCO₃. The aqueous extract was acidified (pH 2.0) with concentrated HCl and extracted with EtOAc. The EtOAc extract was washed with saturated NaCl solution, dried over anhydrous Na₂SO₄ and evaporated to a give the title compound (6.463 g, 82%) as a white foam. TLC(EtOAc-hexane-AcOH; 70:30:2) Rf = 0.50.

Part B: (3S,4RS -3-rAlaninynAmino-5-(2′.3′.5′.6′-TetrafluorophenoxyV4- Hydroxypentanoic Acid tert-Butyl Ester

Starting with [(N-benzyloxycarbonyl)alanmyl]aspartic acid, β-tert-butyl ester and following the methods described in Example 28, Parts B through E gave the title compound as a colorless, viscous oil. TLC(EtOAc-hexane; 1:1) Rf = 0.06.

Part C: (3 S,4RS -3-[ -(Η’-f2-tert-Butylρhenyl)Oxamyl) AlaninyllAmino-5- (2′,3′,5′,6′-Tetrafluorophenoxy)-4-Hvdroxypentanoic Acid tert-Butyl

Ester

To a solution of N-(2-tert-butylphenyl)oxamic acid (0.041 g, 0.19 mmol, prepared from 2-tert-butylaniline by the method described in Example 1, Part A) in

CH C1 (6.0 mL) at 0°C under nitrogen was added hydroxybenzofriazole hydrate (0.030 g) followed by l-ethyl-3 -(3 ‘,3 ‘-dimethyl- l’-aminopropyl)- carbodiimide hydrochloride

(0.050 g, 0.26 mmol). After stirring at 0°C for 10 min, the mixture was treated with

(3S,4RS)-3-(alaninyl)amino-5-(2′,3′,5′,6′-tetrafluorophenoxy)-4-hydroxypentanoic acid tert-butyl ester (0.079 g, 0.19 mmol) and N-methylmorpholine (22 μL, 0.20 mmol).

After stirring at room temperature for 16 hrs, the mixture was partitioned between EtOAc-water. The organic phase was washed with water, 5% KHSO , saturated

NaHCO₃ and saturated NaCl solutions, dried over anhydrous Na₂SO₄ and evaporated to give the crude title compound (0.090 g, 77%) as a viscous oil. TLC(EtOAc-hexane;

1:1) Rf= 0.70.

Part D: r3S -3-rN-rN’-(2-tert-Butylphenyl Oxamyl)AlaninyllAmino-5- (2′,3′,5′.6′-Tetrafluorophenoxy)-4-Oxopentanoic Acid tert-Butyl Ester

To a solution of (3S,4RS)-3-[N-(N’-(2-tert-butylphenyl)oxamyl)alaninyl] amino-5-(2′,3′,5′₃6′-tetrafluorophenoxy)-4-hydroxypentanoic acid tert-butyl ester (0.0.092 g, ca 0.15 mmol) in CH₂C1 (6.5 mL) at room temperature under nitrogen was added iodobenzene diacetate (0.188 g, 0.58 mmol) followed by a catalytic amount of 2,2,6,6-tetramethyl-l-piperidinyloxy free radical (TEMPO, 0.0046 g, 0.03 mmol). After stirring at room temperature for 16 hrs, the mixture was partitioned between EtOAc- water. The organic phase was washed with saturated NaHCO₃ and saturated NaCl solutions, dried over anhydrous Na SO₄ and evaporated to a dryness. The residue (0.096 g) was purified by preparative layer chromatography on silica gel eluting with EtOAc- hexane (3:7) to give the title compound (0.071 g, 77%) as a colorless glass. TLC(EtOAc-hexane; 2:3) Rf = 0.60.

Part E: (3S)-3-rN-(N’-r2-tert-Butylphenyl Oxamyl Alaninyl]Amino-5- (2′ ,3 ‘ , 5 ‘ ,6′ -Tetrafluorophenoxy)-4-Oxopentanoic Acid

To a solution of (3S)-3-[N-(N’-(2-tert- butylphenyl)oxamyl)alaninyl]amino-5-(2′,3′,5′,6′-tetrafluorophenoxy)-4-oxopentanoic acid, tert-butyl ester (0.071 g, 0.11 mmol) in CH₂C1₂(2.5 mL)-anisole(0.05 mL) at room temperature under nitrogen was added trifluoroacetic acid (1.5 mL). The resulting clear solution was stirred at room temperature for 1 hr, evaporated to dryness and chased with toluene-CH₂Cl₂ (1:1). The residue (0.061 g) was purified by preparative layer chromatography on silica gel eluting with MeOH-CH₂Cl₂ (1:9) to give the title compound (0.044 g, 69%) as a colorless glass. MS(ES) for C₂₆H₂₇F₄N₃O₇ (MW 569.51): positive 570(M+H); negative 568(M-H).