Direct-acting antiviral agents for HCV infection affecting people who inject drugs.

Globally, 12 million people are estimated to have injected drugs in the past year, 50% of whom have chronic HCV infection, with people who have previously injected drugs presenting an additional large reservoir of infection. The availability of simple and tolerable interferon-free direct-acting antiviral agents (DAAs) for HCV infection, which have a cure rate of >95% represents one of the most exciting advances in clinical medicine in the past few decades. Adherence and response to DAA therapy among people who inject drugs (PWID) receiving opioid substitution therapy (OST) in clinical trials are comparable to populations without a history of injecting drugs. Further data are required among current PWID not receiving OST. Given the potential prevention benefits of treatment, DAAs have enhanced cost-effectiveness among PWID. As HCV therapy is expanded to populations of PWID with high-risk behaviours for re-exposure, acknowledgement that HCV reinfection will occur is crucial, and appropriate strategies must be in place to maximize prevention of reinfection and offer retreatment for reinfection. This Review will also discuss essential components for broadening access to HCV care for PWID as we strive for the global elimination of HCV infection.