NS5A-P32 Deletion in Hepatitis C Genotype 1b Infection is the Most Refractory Treatment-Mediated Amino Acid Change Exhibiting Resistance to all NS5A Inhibitors.

Hayato Hikita,Tetsuo Takehara

doi:10.1055/s-0039-3402001

Hayato Hikita, Tetsuo Takehara

Open Access

https://doi.org/10.1055/s-0039-3402001

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Journal: Seminars in liver disease	Publication Date: Dec 13, 2019
Citations: 6	License type: CC BY 4.0

Affiliation: Osaka University

Abstract

NS5A-P32 deletion (P32del) is a resistance-associated amino acid change that has recently gained popularity in direct-acting antiviral treatment for chronic hepatitis C. Although not yet detected in naive patients, it appears in 5 to 10% of hepatitis C genotype 1b patients who fail to respond to daclatasvir/asunaprevir and sofosbuvir/ledipasvir treatments. In contrast to signature resistance-associated substitutions, such as substitutions at the NS5A-L31 and NS5A-Y93 positions, it shows complete resistance to all NS5A inhibitors in replicon and cell culture. Studies of humanized liver mice suggest that P32del retains good replication fitness and requires two classes of antivirals, except NS5A inhibitors, to be suppressed effectively. Patients with the P32del virus do not respond to glecaprevir/pibrentasvir but do respond to sofosbuvir/velpatasvir/voxilaprevir, presumably to sofosbuvir + glecaprevir/pibrentasvir, and at least partially to sofosbuvir/velpatasvir + ribavirin. Attention should be given to P32del in patients who experience failure with any NS5A inhibitor, especially those with genotype 1b infection.

Highlights

NS5A-P32 deletion (P32del) is a resistance-associated amino acid change that has recently gained popularity in direct-acting antiviral treatment for chronic hepatitis C
NS5A P32 deletion (P32del), which has never been reported in direct-acting antiviral agents (DAAs)-naive patients, has been reported in patients with hepatitis C virus (HCV) genotype 1b who have failed DAA therapy, including daclatasvir-containing and sofosbuvir/ledipasvir treatments
Most cases of NS5A P32del HCV are reported in Japan, some have been reported in clinical trials conducted in Europe[53] and Western countries.[60,61]

Summary

Introduction

NS5A-P32 deletion (P32del) is a resistance-associated amino acid change that has recently gained popularity in direct-acting antiviral treatment for chronic hepatitis C. NS5A P32 deletion (P32del), which has never been reported in DAA-naive patients, has been reported in patients with hepatitis C virus (HCV) genotype 1b who have failed DAA therapy, including daclatasvir-containing and sofosbuvir/ledipasvir treatments.

Results

Conclusion