Utility of Hepatitis C Viral Load Monitoring On Directly Acting Antiviral Therapy.

Clin Infect Dis. 2015 Mar 2. pii: civ170. [Epub ahead of print]

Utility of Hepatitis C Viral Load Monitoring On Directly Acting Antiviral Therapy.

Sidharthan S1, Kohli A1, Sims Z1, Nelson A2, Osinusi A3, Masur H1, Kottilil S2.

Author information

1Critical Care Medicine Department, National Institutes of Health Clinical Center, National Institutes of Health, Bethesda, Maryland.
2Institute of Human Virology, University of Maryland, Baltimore, Maryland Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland.
3Gilead Sciences Inc., Foster City, California.

Abstract

BACKGROUND: Hepatitis C (HCV) viral loads aided as predictors of treatment response during interferon-based therapy. We evaluated the predictive ability of HCV RNA levels at end of treatment (EOT) for sustained virologic response (SVR12) during interferon-sparing directly acting antiviral (DAA) therapies.

METHODS: HCV genotype 1, treatment naive patients were treated with sofosbuvir and ribavirin for 24 weeks (n=55), sofosbuvir and ledipasvir for 12 weeks (n=20), sofosbuvir, ledipasvir, and GS-9669 for 6 weeks (n=20), or sofosbuvir, ledipasvir, and GS-9451 for 6 weeks (n=19). Measurements of HCV RNA were performed using the Roche COBAS TaqMan HCV test and the Abbott RealTime HCV assay. Positive and negative predictive values (PPV, NPV) of HCV RNA less than the level of quantification (<LLOQ) at EOT for SVR12 were calculated.

RESULTS: All patients treated with sofosbuvir and ribavirin (55/55) had HCV RNA <LLOQ at EOT by the Roche and Abbott assays, but only 38 achieved SVR12 (PPV: 69%). Among patients treated with sofosbuvir, ledipasvir, +/- GS-9669 or GS-9451, 100% (59/59) had HCV RNA <LLOQ by Roche and one relapsed (PPV: 98%). By Abbott, 90% (53/59) had HCV RNA <LLOQ out of which one patient relapsed (PPV: 98%). Notably, six patients with HCV RNA ≥LLOQ at EOT (range: 14-64 IU/mL) achieved SVR12 (NPV: 0%). Quantifiable HCV RNA (range: 15-57 IU/mL) was measured two weeks post-treatment in four individuals, and four weeks post-treatment in one (14 IU/mL).

CONCLUSIONS: Contrary to past experience with interferon-containing treatments, low levels of quantifiable HCV RNA at EOT do not preclude treatment success.

Published by Oxford University Press on behalf of the Infectious Diseases Society of America 2015. This work is written by (a) US Government employee(s) and is in the public domain in the US.