Idenix 
                Begins Proof-of-Concept Study of HCV Protease Inhibitor IDX320
              
              
                
                 
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                        | SUMMARY: 
                          Idenix 
                          Pharmaceuticals announced last week that it has started 
                          a 3-day proof-of-concept study of its experimental hepatitis 
                          C virus (HCV) protease inhibitor IDX320. As 
                          previously reported, researchers presented data 
                          at the recent EASL conference showing that IDX320 showed 
                          good anti-HCV activity in laboratory studies and had 
                          good pharmacokinetic and safety profiles in animals 
                          and HCV negative volunteers. If the latest study produces 
                          favorable results, the company expects to test IDX320 
                          and its investigational HCV polymerase inhibitor IDX184 
                          as a combination regimen. | 
                       
                     
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              Below 
                is an excerpt from a recent Idenix press release describing the 
                drugs and the new study.
              Idenix 
                Pharmaceuticals Initiates Proof-of-Concept Study for Protease 
                Inhibitor IDX320 in Hepatitis C Patients
              Cambridge, 
                Mass. -- June 10, 2010 -- Idenix Pharmaceuticals, Inc. (Nasdaq: 
                IDIX), a biopharmaceutical company engaged in the discovery and 
                development of drugs for the treatment of human viral diseases, 
                today announced that it has initiated a 3-day proof-of-concept 
                study of IDX320, a protease inhibitor for the treatment of hepatitis 
                C virus (HCV) infection, under a Clinical Trial Application (CTA). 
                The study is evaluating IDX320 in treatment-naive hepatitis C 
                genotype 1-infected patients. 
                
                "The potent and multi-genotypic activity demonstrated in 
                vitro, as well as the favorable pharmacokinetics observed 
                in healthy volunteers, suggests a promising profile for further 
                development of IDX320," said Jean-Pierre Sommadossi, PhD, 
                chief executive officer of Idenix. "The landscape for combination 
                development in HCV is evolving quickly. Assuming favorable results 
                from the IDX320 proof-of-concept study, we plan to discuss with 
                regulatory agencies a direct-acting antiviral combination strategy 
                with IDX320 and IDX184, our HCV nucleotide polymerase inhibitor." 
                
                
                Douglas Mayers, MD, Idenix's chief medical officer commented, 
                "We are encouraged by the results seen to date with IDX320 
                and are hopeful that future clinical studies will allow us to 
                continue advancing this program with the ultimate goal of treating 
                a wide range of patients infected with HCV." 
                
                The proof-of-concept trial in HCV-infected patients is a Phase 
                I/II randomized, parallel-arm, double-blind, placebo-controlled 
                study evaluating the safety and antiviral activity of IDX320 in 
                treatment-naive adult patients infected with chronic hepatitis 
                C. The study will evaluate four doses of IDX320, ranging from 
                50 to 400 mg once-per-day, administered for three days. Each cohort 
                of the study will evaluate eight patients randomized six to IDX320 
                and two to placebo. 
                
                About IDX320 
                
                IDX320, a macrocyclic HCV protease inhibitor, is an inhibitor 
                of NS3/4A proteases from genotypes 1a, 1b, 2a and 4a (IC50 values 
                from 0.8 to 1.9 nM), as well as from genotype 3a (IC50=23 nM). 
                IDX320 did not inhibit nine tested cellular proteases (IC50 > 
                10 uM) in vitro, suggesting high selectivity. IDX320 bound 
                tightly to the HCV protease enzyme with a long dissociation half-life 
                (> 9 hours). After single 2 mg/kg oral doses of IDX320 in two 
                animal species, favorable bioavailability and a long plasma half-life 
                were observed, with substantial plasma concentrations 24 hours 
                post dose. Comparable drug exposure was confirmed in healthy volunteers 
                (n=6) receiving a single 200 mg oral dose. Further, no significant 
                in vitro inhibition of human drug metabolizing enzymes, 
                CYP450s and UGT1A1, by IDX320 suggests low potential for drug-drug 
                interactions in patients. 
                
                About IDX184
                
                IDX184 is a novel, liver-targeted nucleotide prodrug of 2'-methyl 
                guanosine monophosphate, which includes Idenix's proprietary liver-targeting 
                technology. This technology enables the delivery of nucleoside 
                monophosphate to the liver, leading to the formation of high levels 
                of nucleoside triphosphate, potentially maximizing drug efficacy 
                and limiting systemic side effects with low, once-daily dosing. 
                IDX184 in combination with pegylated interferon and ribavirin 
                has demonstrated a generally favorable safety profile and potent 
                antiviral activity in an ongoing Phase IIa study. 
                
                About Idenix 
                
                
Idenix 
                Pharmaceuticals, Inc., headquartered in Cambridge, Massachusetts, 
                is a biopharmaceutical company engaged in the discovery and development 
                of drugs for the treatment of human viral diseases. Idenix's current 
                focus is on the treatment of patients with chronic hepatitis C 
                infection. 
                
                For further information about Idenix, please refer to www.idenix.com. 
                
                
                6/8/10
              Source
                Idenix Pharmaceuticals. Idenix Pharmaceuticals Initiates Proof-of-Concept 
                Study for Protease Inhibitor IDX320 in Hepatitis C Patients. Press 
                release. June 10, 2010.