New clinical data show antiviral activity of TMC435, an investigational protease inhibitor (PI) being developed by Tibotec BVBA for the treatment of chronic hepatitis C virus (HCV) infection.
The current standard of care treatment for HCV infection, pegylated interferon (Peg-IFN) combined with ribavirin (RBV), is effective in 30 to 50 percent of patients infected with chronic genotype 1 HCV infection, the most common type in the United States. The development of new therapies and strategies for treating HCV, particularly the introduction of direct antivirals, may offer patients a new option with shorter treatment duration.
TMC435 Phase 2a Study Results
In interim findings from the first 28 days of treatment for the first cohort of fifty (50) treatment naïve HCV+, genotype 1, patients (once daily dose of 25 mg or 75 mg TMC435 versus placebo), both doses showed dose-dependent antiviral activity. TMC435 was administered in combination with PegIFN?-2a/RBV (triple therapy) for 28 days or as monotherapy for seven days and, thereafter, in combination with PegIFN?-2a/RBV (triple therapy) for three weeks. There were neither serious adverse events, nor grade three or four adverse events, related to TMC435 or any safety-related treatment discontinuations during this 28 day treatment period.
The most common adverse events associated with TMC435 were nausea, diarrhea, and headache. There were no clinically relevant changes in laboratory parameters, ECGs, or vital signs. Steady-state plasma trough levels of TMC435 25 mg and 75 mg represented ~10 and >30-fold excess above the HCV replicon EC50 value, respectively.
Mean reductions of HCV RNA from baseline to day seven with TMC435 alone and in triple therapy were 2.63 and 3.47 log10 IU/mL, respectively, in the 25 mg arm, and 3.43 and 4.55 log10 IU/mL in the 75 mg arm. In the 75 mg four-week triple therapy arm, no viral breakthrough was observed; 9/9 patients achieved HCV RNA below lower limit of quantification (<25 IU/mL) and 8/9 patients achieved undetectable HCV RNA (<10 IU/mL) at day 28 (RVR=89 percent).
‘These data provide important information about an emerging new approach to treating HCV,’ said Professor and Chairman Michael Manns, Hannover Medical School, Germany. ‘The discovery and development of new treatments is critical to improving the standard of care for the millions of people living with this disease.’
TMC435 was discovered through a drug discovery collaboration between Medivir and Tibotec.
Release Date: November 3, 2008
Source: Tibotec BVBA
Filed Under: Drug Discovery