Further studies are needed to guide clinicians on whether to extend the duration of treatment with direct-acting antivirals (DAAs) in patients with detectable hepatitis C virus (HCV) RNA who are slow responders, according to a retrospective, single-center study published in the Annals of Pharmacotherapy.

Response-guided therapy using on-treatment viral kinetics to determine treatment duration is used with interferon-based therapies but not for therapy with DAAs. Current guidelines recommend measuring HCV RNA at week 4 of treatment for all patients receiving DAA therapy. However, because of insufficient evidence, no recommendation is provided on whether to discontinue treatment or extend therapy duration in slow responders. Thus, researchers studied whether extending therapy duration in patients with detectable HCV RNA at week 4 of DAA treatment improves the rate of sustained virologic response.

Of the 363 patients included in the study, 58 (16%) received extended therapy. Rates of sustained virologic response at 12 weeks were 100% in the extended-therapy group and 96.7% in the traditional duration group (P =.37). Although no statistically significant benefit of extending therapy was demonstrated, all therapy failures occurred in the traditional-duration group. In addition, no associations with SVR and prespecified patient-specific factors were identified. It is important to note that this study was limited because of the small sample size and likely underpowered to find a statistically significant benefit of extending therapy duration.

The authors concluded, “Based on these findings, a recommendation for extension of therapy cannot be made for patients with detectable HCV RNA at week 4 of treatment at this time.” They suggested, “Cost analyses may help guide recommendations to re-treat rare failures versus extend therapy in all slow responders.”


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Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.

Reference

McKnight AH, Townsend ML, Hashem MG, Naggie S, Park LP, Britt RB. Standard versus extended duration direct-acting antiviral therapy in hepatitis C patients with slow response to treatment. Ann Pharmacother. doi:10.1177/1060028020921166