Kosaka K, Imamura M, Hayes C N, Abe H, Hiraga N, Yoshimi S, Murakami E, Kawaoka T, Tsuge M, Aikata H, Miki D, Ochi H, Matsui H, Kanai A, Inaba T, Chayama K
Department of Gastroenterology and Metabolism, Applied Life Science, Institute of Biomedical & Health Science, Hiroshima University, Hiroshima, Japan.
J Viral Hepat. 2015 Feb;22(2):158-65. doi: 10.1111/jvh.12271. Epub 2014 Jun 19.
Daclatasvir (DCV) and asunaprevir (ASV) are NS5A and NS3 protease-targeted antivirals respectively, currently under development for the treatment of chronic hepatitis C virus (HCV) infection. We analysed the relationship between pre-existing drug-resistant variants and clinical outcome of the combination treatment with DCV and ASV. Ten patients with HCV genotype 1b were orally treated with a combination of ASV and DCV for 24 weeks. The frequencies of amino acid (aa) variants at NS3 aa positions 155, 156 and 168 and at NS5A aa31 and 93 before and after treatment were analysed by ultra-deep sequencing. We established a minimum variant frequency threshold of 0.3% based on plasmid sequencing. Sustained virological response (SVR) was achieved in 8 out of 10 patients (80%), and relapse of HCV RNA after cessation of the treatment and viral breakthrough occurred in the other two patients. Pre-existing DCV-resistant variants (L31V/M and/or Y93H; 0.9-99.4%) were detected in three out of eight patients who achieved SVR. Pre-existing DCV-resistant variants were detected in a relapsed patient (L31M, Y93H) and in a patient with viral breakthrough (Y93H); however, no ASV-resistant variants were detected. In these patients, HCV RNA rebounded with ASV- and DCV- double resistant variants (NS3 D168A/V plus NS5A L31M and Y93H). While pre-existing DCV-resistant variants might contribute to viral breakthrough in DCV and ASV combination therapy, the effectiveness of prediction of the outcome of therapy based on ultra-deep sequence analysis of pre-existing resistant variants appears limited.
达卡他韦（DCV）和阿舒瑞韦（ASV）分别是靶向NS5A和NS3蛋白酶的抗病毒药物，目前正处于开发阶段，用于治疗慢性丙型肝炎病毒（HCV）感染。我们分析了预先存在的耐药变异与DCV和ASV联合治疗临床结果之间的关系。10例HCV基因1b型患者接受ASV和DCV联合口服治疗24周。通过超深度测序分析治疗前后NS3氨基酸（aa）位置155、156和168以及NS5A aa31和93处氨基酸变异的频率。基于质粒测序，我们确定了0.3%的最小变异频率阈值。10例患者中有8例（80%）实现了持续病毒学应答（SVR），另外2例患者在治疗停止后出现HCV RNA复发和病毒突破。在实现SVR的8例患者中，有3例检测到预先存在的DCV耐药变异（L31V/M和/或Y93H；0.9 - 99.4%）。在1例复发患者（L31M，Y93H）和1例病毒突破患者（Y93H）中检测到预先存在的DCV耐药变异；然而，未检测到ASV耐药变异。在这些患者中，HCV RNA因ASV和DCV双重耐药变异（NS3 D168A/V加上NS5A L31M和Y93H）而反弹。虽然预先存在的DCV耐药变异可能导致DCV和ASV联合治疗中的病毒突破，但基于预先存在的耐药变异的超深度序列分析预测治疗结果的有效性似乎有限。
