What is sustained virologic response (SVR)?
The same measurements that are used to determine disease severity (ALT, HCV RNA, and histological appearance on liver biopsy) are also used to determine if a therapeutic response has been achieved. Treatment for HCV is generally 48 weeks, or perhaps 24 weeks. In HIV/HCV coinfected individuals, 48 weeks of treatment is likely going to be the standard of care. The percent of patients with undetectable virus (<100 copies/ml) when treatment is stopped is called the End-Of-Treatment (ETR) Response. The key evaluation of therapy is the SVR. The SVR is the percent of patients with <100 copies/ml 24 weeks after treatment is stopped. The reason the SVR is the more important evaluation of the success of therapy is because patients who achieve an SVR are more likely to retain undetectable viral loads for years. Several small studies show that well over 90% of patients who achieve an SVR still have undetectable HCV for as long as they have been followed so far which is as far as 11 years. Some pat
