Hepatitis C treatment from "response-guided" to "resource-guided" therapy in the transition era from interferon-containing to interferon-free regimens.

Peginterferon/ribavirin has been the standard-of-care for chronic hepatitis C virus (HCV) infections: 48 weeks for genotype 1 or 4 (HCV-1/4) and 24 weeks for HCV-2/3. Response-guided therapy recommended shorter 24- and 16-week regimens for HCV-1 with lower baseline viral loads (< 400 000-800 000 IU/mL) and rapid virological response (RVR, undetectable HCV RNA at week 4) and HCV-2/3 with RVR, respectively; and extending to 72 and 48 weeks for HCV-1 slower responders and HCV-2 non-RVR patients, respectively, to improve the efficacy. The progress of directly acting antivirals (DAA), moving from interferon-containing regimens in 2011 to interferon-free regimens in 2013, has greatly improved the treatment success. Interferon-containing regimens include boceprevir or telaprevir or simeprevir or daclatasvir plus peginterferon/ribavirin, 24-48 weeks, for HCV-1 or 4. However, adding these DAA has no benefit for HCV-1 with lower baseline viral loads/RVR. Instead, 12-week sofosbuvir plus peginterferon/ribavirin attained sustained virological response rates of > 90% for HCV-1/3-6. Interferon-free regimens include two main categories: NS5B nucleotide inhibitor (sofosbuvir)-based regimens and NS3/4A inhibitor/NS5A inhibitor-based regimens (daclatasvir/asunaprevir, paritaprevir/r/ombitasvir/dasabuvir and grazoprevir/elbasvir). About 8-24 weeks interferon-free regimens could achieve sustained virological response rates of 82-99% for corresponding HCV genotypes. Although the newly DAA interferon-free regimens have high efficacy and safety, the huge budget impact increases the treatment barriers. The current recommendation should, therefore, base on the availability, indication, and cost-effectiveness in the transition era of DAA. Based on the concept of "resource-guided therapy," peginterferon/ribavirin might be applied for easy-to-treat interferon-eligible patients in resource-constrained areas. Prioritizing patients for interferon-free regimens according to "time-degenerative factors" (age and fibrosis) is justified before the regimens becoming available and affordable.