Selective inhibitors of hepatitis C virus replication

Area of Science:

• Hepatology
• Virology
• Drug Discovery

Background:

• Hepatitis C virus (HCV) chronically infects over 170 million people worldwide, posing a significant risk for fatal liver disease.
• Current standard therapy (pegylated interferon alfa plus ribavirin) exhibits limited efficacy (50-60%) and notable side effects.
• Development of effective antiviral strategies was historically impeded by a lack of suitable cell culture models for HCV propagation.

Purpose of the Study:

• To review advancements in HCV research, focusing on novel antiviral strategies and therapeutic targets.
• To discuss the development and importance of HCV cell culture and mouse models in drug efficacy assessment.
• To explore potential therapeutic approaches, including combination therapies and alternative agents like cyclosporin A analogues.

Main Methods:

• Establishment of the HCV replicon system (1999) and robust HCV cell culture models (2005) facilitated research.
• Development of mouse models for in vivo efficacy assessment of novel antiviral drugs.
• Investigation of viral serine protease and RNA-dependent RNA polymerase as key therapeutic targets.

Main Results:

• HCV protease and polymerase inhibitors have demonstrated encouraging results in early clinical studies.
• Preclinical data indicate a high potential for rapid development of viral resistance to these inhibitors.
• Alternative strategies, such as non-immunosuppressive cyclosporin A analogues, show potent anti-HCV activity and distinct resistance profiles.

Conclusions:

• Combination therapy with drugs having different mechanisms of action and resistance profiles is likely essential for effective HCV treatment.
• Alternative antiviral strategies, exemplified by cyclosporin A analogues, offer a promising avenue, particularly due to their potentially different resistance patterns compared to protease or polymerase inhibitors.
• Continued research into novel therapeutic targets and combination strategies is crucial for overcoming HCV and managing drug resistance.