title: Danoprevir, a small-molecule NS3/4A protease inhibitor for the potential oral treatment of HCV infection.
abstract: Danoprevir (ITMN-191; RG-7227), under development by InterMune Inc and Roche Holding AG, is a promising, potent NS3/4A protease inhibitor for the oral treatment of HCV infection. Preclinical data demonstrated that danoprevir binds with high affinity and dissociates slowly from the HCV NS3 protease, allowing high liver drug exposure with only modest plasma drug exposure. A phase Ib, 'IFN-free' clinical trial demonstrated that danoprevir, combined with the HCV polymerase inhibitor RG-7128 (Pharmasset Inc/Roche Holding AG), was effective in reducing HCV-RNA levels in a large proportion of treatment-naïve patients with HCV infection and in approximately half of previously non-responsive patients with HCV-1 infection, without resistance or safety concerns. In a phase IIb trial in treatment-naïve patients with HCV-1 infection, danoprevir plus pegylated IFNalpha2a and ribavirin resulted in undetectable levels of HCV-RNA in the majority of patients, without any evidence of viral resistance; however, the high-dose danoprevir arm was prematurely terminated because of grade 4 ALT elevations. Phase I trials have also demonstrated that ritonavir boosting improved the pharmacokinetic profile of danoprevir; therefore, at the time of publication, a phase IIb trial to evaluate ritonavir-boosted, low-dose danoprevir in combination with RG-7128 was planned.
authors: Athens University Medical School, Hippokration General Hospital, 2nd Department of Internal Medicine, 114 Vas Sofias Avenue, 11527 Athens, Greece.
authors: Melanie
authors: M
authors: Deutsch
authors: George V
authors: GV
authors: Papatheodoridis
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D002986:Clinical Trials as Topic; D003521:Cyclopropanes; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D004359:Drug Therapy, Combination; D000882:Haplorhini; D016174:Hepacivirus / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D006526:Hepatitis C / Q000188:drug therapy* / Q000821:virology; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use; D054833:Isoindoles; D007769:Lactams / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D047029:Lactams, Macrocyclic; D011092:Polyethylene Glycols / Q000627:therapeutic use; D011392:Proline / Q000031:analogs & derivatives; D011480:Protease Inhibitors / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins; D012254:Ribavirin / Q000627:therapeutic use; D019438:Ritonavir / Q000627:therapeutic use; D013449:Sulfonamides / Q000009:adverse effects / Q000493:pharmacokinetics / Q000494:pharmacology / Q000627:therapeutic use*; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D000998:Antiviral Agents; D003521:Cyclopropanes; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D054833:Isoindoles; D007769:Lactams; D047029:Lactams, Macrocyclic; D011092:Polyethylene Glycols; D011392:Proline; D011480:Protease Inhibitors; D011994:Recombinant Proteins; D012254:Ribavirin; D019438:Ritonavir; D013449:Sulfonamides; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C553752:danoprevir; C100416:peginterferon alfa-2a