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Exciting news from Inhibitex about their anti-Hepatitis C drug, INX-189

8 November 2011

3D structure/image of INX-189 anti-hepatitis C drug

3D structure/image of INX-189 an anti-hepatitis C drug synthesised in the School

 More information here 


Inhibitex, the US biopharmaceutical company, which is working on potential anti-viral drugs with Prof Chris McGuigan’s laboratory in the Welsh School of Pharmacy, have just reported that INX-189 produced a more than 10,000 reduction in viral load in patients treated with 200mg daily for 7 days, with only minimal side effects.   



 INV-189 viral reduction after 7 days

INV-189 viral reduction after 7 days

Click for full sized image  123.0 Kb



This drug, first synthesised  about three years ago in the laboratory in the Welsh School of Pharmacy, is active against Hepatitis C.  This disease affects some 170 million individuals worldwide (3% of the human population) and current treatment  is unsatisfactory.  




Professor McGuigan,. who is also a member of the Board of Directors of Inhibitex, warmly welcomed this news, saying:  "It is big news, and sent the share price up 130% on the day (the largest rise on the whole of NASDAQ) to reach a current valuation of $760M. This is on the basis of two potential drugs, both from Cardiff, FV100 for shingles and INX-189 for HCV. The HCV market is much larger and main value driver. Certainly >90% of the value comes from HCV.

The news (see link below for full text) essentially reveals that we have a highly powerful and effective single drug therapy for HCV, based on these early trials in patients. A single daily oral dose of 200mg  knocked the virus back over 10,000 fold (4.25 log in fact) after 7 days (7 doses). This makes INX-189 amongst the very most potent agents for HCV in the World. In the patients dosed so far it also seems very safe, with no serious side effects.  By comparison, the current therapy involves a weekly injection, and a tablet, both of which have side-effects, and therapy lasts for almost a year, and fails in many patients. Of course, they are early trials, and we need major phase 3 studies before we could apply for a license, but the data are incredibly encouraging; hence the jump in valuation."


We are very pleased with the progress we have made in the clinical development of INX-189 over the past several months, as well as the continued potent, dose-dependent antiviral activity it is demonstrating as monotherapy in genotype 1 treatment-naïve HCV patients,” stated Russell H. Plumb, President and CEO of Inhibitex, Inc. “We look forward to expanding the scope of our Phase 2 program to include interferon-free combinations of INX-189 with other antiviral agents in HCV genotype 1, 2, and 3 patients in 2012.”



For  recent scientific papers describing the development of INX-189 see


INX-08189, a Phosphoramidate Prodrug of 6-O-Methyl-2’-C-Methyl Guanosine, is a Potent Inhibitor of Hepatitis C Virus Replication with Excellent Pharmacokinetic and Pharmacodynamic Properties.  

J.H. Vernachio, B. Bleiman, K.D. Bryant, S. Chamberlain, D. Hunley, J. Hutchins, B. Ames, E. Gorovits, B. Ganguly, A. Hall, A. Kolykhalov, Y. Liu, J. Muhammad, N. Raja, R.C. Walters, J. Wang, K. Williams, J.M. Patti, G. Henson, K. Madela, M. Aljarah, A. Gilles, C. McGuigan    

Antimicrob Agents, Chemother, 2011, 1843-1851.


Design, synthesis and evaluation of a novel double pro-drug: INX-08189.  A new clinical candidate for hepatitis C virus

Christopher McGuigan, Karolina Madela, Mohamed Aljarah, et al.   

Bioorganic & Medicinal Chemistry Letters 20 (2010) 4850–4854


Phosphoramidate ProTides of 2’-C-Methylguanosine as highly potent inhibitors of hepatitis C virus. Study of their in vitro and in vivo properties.

 C. McGuigan, A. Gilles, K. Madela, M. Aljarah, et al.

J. Med. Chem., 2010, 4949-4957.


A current Powerpoint presentation from Prof McGuigan describing Pro Tides is available here. 


See also

 Full text of Inhibitex press release from 4th  Nov. 2011 



Inhibitex, Inc.   company web-site


Prof Chris McGuigan

Position:Professor of Medicinal Chemistry
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Telephone: +44 (0)29 208 74537 Extension: 74537