Evaluation of Resistance-Associated Substitutions in NS5A Using Direct Sequence and Cycleave Method and Treatment Outcome with Daclatasvir and Asunaprevir for Chronic Hepatitis C Genotype 1

Abstract

BackgroundThe aim of this study was to evaluate the efficacy of daclatasvir plus asunaprevir therapy in patients infected with hepatitis C virus and determine its relevance to resistant variants.MethodsA total of 629 consecutive patients infected with hepatitis C virus genotype 1 were assessed. Daclatasvir (60 mg/day) plus asunaprevir (200 mg/day) was given for 24 weeks. The virological responses and resistance-associated substitutions of hepatitis C virus mutants were examined by the direct sequence and cycleave methods were evaluated.ResultsOverall, 89.4% (555/621) of patients exhibited a sustained virological response (SVR). The SVR rates in the patients with wild type, mixed, and mutant type Y93 by direct sequencing were 92.5% (520/562), 70.3% (26/37), and 42.9% (9/21), respectively. The SVR rates in the patients with 100%, 90%, 80%-30%, and 20%-0% Y93 wild by the cycleave method were 93.4% (456/488), 88.2%(30/34), 56.0%(14/25), and 36.8%(7/19), respectively. In contrast, the SVR rates for the wild type and mixed/mutant type L31 by direct sequencing were 90.2% (534/592) and 72.4% (21/29), respectively. In the multivariate analyses, the wild type Y93, no history of simeprevir therapy, the wild type L31, and low HCV RNA level were independent factors of SVR.ConclusionNS5A resistance-associated substitutions, especially Y93H, were major factors predicting the SVR. Although direct sequencing can predict the SVR rate, the cycleave method is considered to be more useful for predicting the SVR when used in combination.

Systematic review with meta‐analysis: effectiveness and tolerability of interferon‐free direct‐acting antiviral regimens for chronic hepatitis C genotype 1 in routine clinical practice in Asia

“…Of the 8262 citations and 23 additional manually searched articles evaluated, we included 41 studies published in full articles (Figure ) . Of those, four studies were used only to extract data for subgroup analysis because the overall SVR data were already reported and extracted for overlapping populations in other four included studies .…”

Daclatasvir and asunaprevir treatment in patients infected by genotype 1b of hepatitis C virus with no or subtle resistant associated substitutions (RAS) in NS5A‐Y93

“…Furthermore, another drawback is that the method for determination of NS5A‐Y93 RAS was not uniform and therefore the precise threshold for “subtle” amount of NS5A‐Y93 RAS might be different. However, in general, the detection limit of NS5A‐Y93 RAS by direct sequencing is reported to be 20%, and patients whose RAS levels were lower than these levels had almost the same SVR rate . We therefore consider that the level of the threshold of this study to judge as “subtle amount of RAS” in the present study were valid.…”

“…However, in general, the detection limit of NS5A-Y93 RAS by direct sequencing is reported to be 20%, 17,22 and patients whose RAS levels were lower than these levels had almost the same SVR rate. 15,34 We therefore consider that the level of the threshold of this study to judge as "subtle amount of RAS"…”

“…We determined RAS for HCV NS5A-Y93H using either of the following three methods; direct sequencing, 14,15 the invader assay, 16,17 or the Cycleave assay. 14,15 Among them, 113 patients were detected by direct sequences, 69 patients were detected by invader assay, and 436 patients were detected by Cycleave assay. Each detection limit was 20% of Y93 RAS in direct sequence, <1% in invader assay, and 0% in Cycleave assay.…”

Usefulness of semiquantitative PCR‐Invader assay for selecting candidates for daclatasvir plus asunaprevir combination therapy among patients with hepatitis C virus genotype 1b

“…treated 592 patients with HCV1 who were examined by the Cycleave method, another highly sensitive assay to detect minor variants. The SVR results for patients with rates of Y93H mutants of 0%, 10%, and 20% by the Cycleave method were 93.4% (456/488), 88.2% (30/34), and 50.0% (6/12), respectively . In Japan, Cycleave, DS, Q‐PI, and SQ‐PI are frequently used methods to detect pretreatment NS5A RAVs.…”