Small molecule and novel treatments for chronic hepatitis C virus infection

Viral response to specifically targeted antiviral therapy for hepatitis C and the implications for treatment success

Currently, hepatitis C virus (HCV) antiviral therapy is characterized by long duration, a multitude of side effects, difficult administration and suboptimal success; clearly, alternatives are needed. Collectively, specifically targeted antiviral therapy for HCV (STAT-C) molecules achieve rapid viral suppression and very high rapid virological response rates, and improve sustained virological response rates. The attrition rate of agents within this class has been high due to various toxicities. Regardless, several STAT-C molecules are poised to become the standard of care for HCV treatment in the foreseeable future. Optimism must be tempered with concerns related to the rapid development of drug resistance with resulting HCV rebound. Strategies including induction dosing with interferon and ribavirin, use of combination high-potency STAT-C molecules and an intensive emphasis on adherence to HCV antiviral therapy will be critical to the success of this promising advance in HCV therapy.

Retreating chronic hepatitis C with daily interferon alfacon-1/ribavirin after nonresponse to pegylated interferon/ribavirin: DIRECT results

Up to 50% of patients with chronic hepatitis C fail to respond to initial therapy with pegylated interferon (PEG-IFN) and ribavirin (RBV). With unsuccessful viral eradication, these patients remain at risk for developing progression of their liver disease. Retreatment with PEG-IFN/RBV yields sustained virologic response (SVR) rates that are under 10%. A wholly synthetic interferon, interferon alfacon-1 or consensus interferon (CIFN) given with RBV, was evaluated in patients who failed initial PEG-IFN/RBV therapy. The intent-to-treat analysis included 487 patients; 245 received CIFN 9 microg/day and RBV, and 242 received CIFN 15 microg/day and RBV. Within this group of patients, 59.3% had documented advanced fibrosis at baseline liver biopsy (stage F3 or F4). SVR rates were 6.9% (17/245 patients) in the 9 microg group and 10.7% (26/242) in the 15 microg group. In the intent-to-treat analysis, SVR rates were higher among patients with a >2-log(10) decrease in hepatitis C virus RNA during prior PEG-IFN/RBV therapy: 11% (4/38) in the 9 mug group and 23% (7/31) in the 15 microg group. Among patients with lower baseline fibrosis scores (F0-F3), SVR rates were 7.8% (15/192) in the 9 microg group and 13.1% (23/175) in the 15 microg group. In this same group of patients (F0-F3), if a >2-log(10) decrease in hepatitis C virus RNA with previous PEG-IFN/RBV treatment was achieved, SVR rates improved to 10.7% and 31.6% in the 9 microg and 15 microg groups, respectively. CIFN/RBV combination retreatment was safe and well tolerated.

CONCLUSION

Retreatment of PEG-IFN and RBV nonresponders with CIFN and RBV is safe and efficacious and can be considered a retreatment strategy for patients failing previous therapy with PEG-IFN/RBV, especially in interferon-sensitive patients with lower baseline fibrosis scores.

Management complexities of HIV/hepatitis C virus coinfection in the twenty-first century

Because of shared routes of transmission, hepatitis C virus (HCV) coinfection is common among HIV-infected persons. Because of the effectiveness of antiretroviral therapy, chronic HCV has now emerged as a major cause of morbidity and mortality in this population. Because chronic HCV is highly prevalent among HIV-infected patients and has a rapid disease progression, antiviral therapy with pegylated interferon plus ribavirin is critical for the long-term survival of HIV/HCV-coinfected patients. In this article, the authors review the (1) epidemiology of HCV among HIV-infected individuals, (2) effect of HIV on the natural history of chronic HCV, (3) impact of antiretroviral therapy on HCV coinfection, and (4) management of chronic HCV in the HIV-infected person.