Surrogate markers of efficacy for medical treatment of viral hepatitis.

As a chronic illness, hepatitis presents a challenge for clinical research, regulatory bodies, and clinicians treating patients - how can one adequately assess the effectiveness of antiviral therapy after years or decades of undiagnosed infection? Because the outcome of infection with hepatitis B or C (HBV, HCV) may follow years or decades of infection, the clinical benefit of a therapeutic may not be recognized during the short time frames of most human clinical trials. This is in clear contrast to many other therapeutics, where the outcome and efficacy can be evaluated in few weeks or months. In HBV and HCV, it is impractical to wait until the disease has abated to determine a drug's benefit, so surrogate markers that can predict disease outcome are essential to developing effective therapies. This review will highlight the ability of surrogate markers to detect early disease and to evaluate the effectiveness of HBV and HCV therapies.