The success of HCV treatment is defined as an undetectable HCV viral load test six months after completing a successful course of HCV treatment. This is called a sustained virological response, or SVR. People who achieve an SVR are generally considered to be “cured” virologically. However, even when people achieve an SVR, they may still be at higher risk for developing liver cancer later on, especially if they waited to treat their HCV until they had cirrhosis.

Several different terms are also used throughout the course of treatment to help predict whether people are likely to achieve an SVR, and in one case, whether or not they should continue treatment after the first 12 weeks. These terms are:

• Rapid virological response (RVR), which is an undetectable HCV level after four weeks of treatment
• Early virological response (EVR), which is an undetectable HCV level after 12 weeks of treatment
• End of treatment response (ETR), which is an undetectable HCV level at the completion of treatment