Clinical trials of treatment for hepatitis C virus infection in HIV-infected patients: past, present, and future.

Coinfection with hepatitis C virus (HCV) and human immunodeficiency virus (HIV) type 1 is common. Rates of liver-related morbidity and mortality have been increasing in the coinfected population, and treatment for HCV infection in this group remains a challenge. The HCV-monoinfected population, especially patients infected with HCV genotype 2 or 3, has benefited dramatically from the advent of treatment with pegylated interferon plus ribavirin; rates of sustained virological response approach 55%. Coinfected patients lag behind, with rates of sustained virological response ranging between 26% and 40%; rates of sustained virological response are even lower among patients infected with HCV genotype 1. It is encouraging, however, that therapies known to be safe for treating monoinfected patients have been proven to be generally safe and well tolerated in patients coinfected with HIV and HCV, as well. Future therapies, some of which are currently in development, will likely include new targets, such as helicase and polymerase. It is hoped that, as more-effective agents are discovered, the disparity in treatment response will diminish.