11. Hepatitis B: Interferon Boosts Cure Rate, Tenofovir Works Long-Term

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Compared with hepatitis C and HIV, the hepatitis B treatment field moves slowly, but a number of studies presented in 2014 advanced knowledge about how best to treat chronic hepatitis B virus (HBV) with existing therapies and offered some promising agents in the pipeline. 

Antiviral therapy using nucleoside/nucleotide analogs such as tenofovir (Viread), entecavir (Baraclude), or adefovir (Hepsera) is the mainstay of hepatitis B treatment. While antivirals are effective at suppressing HBV viral load over the long term, relapse is common after stopping therapy and they rarely lead to a cure, as indicated by the loss of hepatitis B surface antigen (HBsAg) and seroconversion, or development of anti-HBs antibodies.

Several studies have looked at combining antivirals with pegylated interferon, which stimulates the body's natural immune responses against HBV. As reported at the AASLD Liver Meeting in November, alarge international study showed that chronic hepatitis B patients who added pegylated interferon to tenofovir for 48 weeks were more likely to experience HBsAg loss than those who used interferon or tenofovir alone, although it remained uncommon even with the combination (7%, 3%, and 0%, respectively).

Another study at AASLD confirmed that staying on tenofovir is a feasible approach. Almost all patients treated with tenofovir for 8 years maintained viral suppression, side effects were minimal, kidney and bone problems were rare, and there was no evidence of drug resistance. But even after such prolonged antiviral therapy, HBsAg loss and seroconversion remained uncommon.

Looking further down the pipeline, a novel siRNA therapy known ARC-520was associated with a reduction in HBsAg levels when used with entecavir. However, in early January the U.S. Food and Drug Administration asked for lower doses and may place a partial hold on trials due to safety concerns.

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