Direct acting antivirals failure: cause and retreatment options

ABSTRACT

Introduction: Chronic hepatitis C (HCV) infection is a systemic life-threatening condition that can lead to hepatic and extra-hepatic complications. Sustained virological response (SVR) is associated with a regression of most liver and non-liver manifestations, which reduce mortality. The history of HCV infection therapy radically changed in the last decade, with the introduction of the first generation direct acting antivirals (DAAs).

Areas covered: The new regimens, based on the combination of 2 or 3 second-generation DAAs, allow SVR, namely hepatitis C infection cure, in more than 95% of cases. Antiviral treatment is generally well tolerated and its duration (8–16 weeks) varies depending on the stage of liver fibrosis, HCV genotype, prior treatment, baseline viral load, presence of resistance-associated variants (RAV). This review evaluates the cause, the efficacy and safety results in case of DAAs failure.

Expert commentary: Despite the excellent efficacy of DAAs, a minority of patients (4–5%) still fail to eradicate HCV, mainly related to poor adherence but also to relapse or viral breakthrough. The main causes of a failure of DAAs are the presence of advanced liver disease, suboptimal treatment and NS5A mutations. Many questions regarding resistant associated substitutions (RASs) prevalence and clinical relevance in re-treatment remain unanswered.     

Early predictors of antiviral treatment response in liver transplant recipients with recurrent hepatitis C genotype 1

The success of current antiviral treatment for hepatitis C virus (HCV) recurrence in liver transplant (LT) recipients remains limited. We aimed at evaluating the value of IL28B genotype and early viral kinetics to predict response to standard treatment in the transplant setting. We retrospectively evaluated 104 LT recipients treated for HCV genotype 1 recurrence between 2001 and 2010. Baseline variables, including IL28B genotype, and early viral kinetics were compared among patients who did or did not achieve a sustained virological response (SVR). Logistic regression analyses of candidate variables were conducted to generate a reliable predictive model based on the minimum set of variables. Twenty‐nine (28%) achieved an SVR. On multivariate analysis, the magnitude of HCV RNA decline at 4 weeks (OR: 3.74, 95% CI: 1.64–9.39; P = 0.003) and treatment compliance (OR: 35.27, 95% CI: 3.35–365.54; P = 0.003) were the only independent predictors of SVR. Favourable recipient IL28B genotype significantly correlates with virological response at week 4 (OR 3.23; 95% CI, 1.12–9.15; P = 0.03). By logistic regression analysis, a model including donor age, recipient rs12979860 genotype and viral load at 4 weeks showed the best predictive value for SVR with an area under the receiver operating curve of 0.861. Favourable recipient IL28B genotype strongly correlates with the viral response at week 4 which is the strongest predictor of response. The combination of recipient IL28B genotype and donor age with the week 4 response reliably estimates the probability of SVR early on‐treatment and may facilitate therapeutic strategies incorporating new antiviral agents.     

The role of serum sphingolipids as potential biomarkers of non-response to direct acting antiviral therapy in chronic hepatitis C virus infection

Elimination strategies of chronic hepatitis C virus (HCV) infection aim to optimize the high antiviral potency of direct-acting antivirals (DAAs). Sphingolipids (SLs) constitute bioactive lipid compounds with a remarkable second messenger potential. SL levels associate with responsiveness to interferon treatment in HCV-patients, thus prompting the question whether failure to DAAs can be predicted by the serologic sphingolipidomic profile. Liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS) was used to retrospectively quantify various sphingolipid metabolites in baseline serum samples of 97 chronic HCV patients with DAA failure compared with an age-matched cohort of 95 HCV-patients with sustained virological response (SVR). Sphingosine, sphinganine, sphingosine-1-phosphate (S1P) and sphinganine-1-phosphate (SA1P) serum concentrations were significantly upregulated at baseline in patients with DAA failure compared to patients with SVR. Similarly, GluC24:1Cer baseline levels were significantly upregulated in patients with DAA failure compared to the patients with SVR. However, GluC18Cer serum levels showed decreased baseline levels for patients with DAA failure compared to patients with SVR. In multivariate analysis sphinganine (OR 0.08494, CI 0.07393–0.9759, p = .021223), SA1P (OR 0.9818, CI 0.9653–0.9987, p = .034801), GluCerC18 (OR 1.0683, CI 1.0297–1.1104, p = .000786) and GluCer24:1 (OR 0.9961, CI 0.994–0.998, p = .000294) constituted independent predictors of treatment response. In conclusion, serum sphingolipid concentrations, in particular sphingosine, sphinganine and their derivatives S1P and SA1P as well as glucosylceramides may identify at baseline the minority of HCV patients with DAA failure. Serum sphingolipids could constitute additional biomarkers for national treatment strategies aiming to eliminate HCV infection.     

Treating hepatitis C: current standard of care and emerging direct-acting antiviral agents

Summary. During the late 1990s and early 2000s, major advances were made in the treatment of patients with chronic hepatitis C virus (HCV) infection. Interferon, combination interferon plus ribavirin (RBV) and pegylated interferon plus RBV increased sustained virologic response (SVR) rates from ~5% to ~40-80%, depending on the genotype of HCV infection. Advances in molecular biology have allowed investigators to begin to understand the mechanisms of HCV infection and replication. Advances in understanding of viral kinetics have provided tools to identify patients who are most likely to attain SVR. With the advances in the science of HCV infection, the first part of the 21st century has seen the development and early introduction of a number of direct-acting antiviral (DAA) drugs. These novel medications interfere with critical steps in HCV replication and have the potential to significantly increase SVR rates. This article will review the key elements of HCV replication and evaluate the various classes of new and investigational DAA that have the potential to create a revolution in the management of patients with chronic hepatitis C.     

Real‐world experiences with direct‐acting antiviral agents for chronic hepatitis C treatment

As direct‐acting antiviral (DAA) agents become more readily available for the treatment of chronic hepatitis C, it is important to understand real‐world treatment experiences. In order to assess the effectiveness of DAA regimens and factors that influence sustained virologic response (SVR) rates in the Veterans Affairs healthcare system, we retrospectively identified veterans with chronic hepatitis C who were treated with DAAs from January 2014 to June 2015. We determined SVR rates and collected data on demographics, genotype (GT), previous interferon‐based treatment, antiviral regimens, and co‐morbidities (HIV, prior solid organ transplant, haemodialysis) for analysis. Of 15 720 veterans, the majority were infected with genotype 1a (GT1a, 60.5%). Excluding the special populations, the overall cohort SVR rate was 92%. Compared to treatment‐experienced patients, treatment‐naïve patients had significantly higher SVR rates (90% vs 92%, P = .006). Subgroups associated with lower likelihood of achieving SVR‐included African Americans (OR 0.79, 95% CI 0.69‐0.91), GT3 (OR 0.65, CI 0.50‐0.86), and cirrhosis (OR 0.91, CI 0.84‐0.99) or decompensated cirrhosis (ascites: OR 0.78, CI 0.67‐0.91, variceal bleed: OR 0.75, CI 0.57‐0.99). The only treatment regimen independently associated with lower SVR rates was SOF+RBV+IFN (OR 0.65, CI 0.50‐0.84). Special populations achieved high SVR rates: HIV 92%, haemodialysis 93%, liver transplant 96% and renal transplant 94%. In conclusion, overall SVR rates were comparable to those reported in clinical trials and carried over to historically more difficult‐to‐treat patients. Several patient‐ and treatment‐related factors were identified as independent predictors of treatment failure and suggest subgroups to target for efforts to improve therapeutic strategies.     

Impact of different sofosbuvir based treatment regimens on the biochemical profile of chronic hepatitis C genotype 4 patients

Background: Huge efforts have been made to control chronic HCV in Egypt with introduction of Direct-Acting Antivirals (DAAs). Current study aims at evaluating effect of various DAA regimens on liver biochemical profile and haematological indices during treatment.

Methods: 272 patients with chronic HCV genotype 4 treated by different DAA regimens (SOF/RBV, SOF/DAC ± RBV, SOF/SIM) for a duration of 12 or 24 weeks in Kasr Alainy Viral Hepatitis Center, Cairo University were followed up for serum bilirubin (BIL), albumin (ALB), alanine transaminase (ALT), aspartate aminotransferase (AST), prothrombin concentration, international normalized ratio (INR), and CBC at baseline, week-4 and end of treatment.

Results: Mean age was 54 years. Males comprised 64.7%, 72.4% were treatment-naïve, 39% were cirrhotic. Overall SVR12 rate was (93.4%). With all regimens, ALT and AST declined after treatment. In cirrhotics, there was a rise in BIL and INR; with no change in ALB and a decrease in White blood cells. Drop in Hemoglobin and platelets in cirrhotic patients were noted with SOF/RBV, while SOF/SIM showed rise in BIL.

Conclusion: DAAs are safe and effective in genotype 4 chronic HCV patients. It improves liver necro-inflammatory markers in cirrhotics and non-cirrhotics. Cirrhotic patients require careful observation being more vulnerable for treatment related complications.     

Interferon‐free therapies for patients with chronic hepatitis C genotype 3 infection: A systematic review

Treatment of hepatitis C virus (HCV) infection with genotype 3 remains a challenge. The HCV elimination rate with direct‐acting antivirals (DAAs) is lower than the values reported for other HCV genotypes. In addition, genotype 3‐infected patients have a higher risk of disease progression and hepatocellular carcinoma. The aim of this study was to review the relevant literature concerning the treatment of HCV genotype 3 patients with interferon‐free regimens. A literature search was conducted in the PubMed/Medline, Embase and Web of Science electronic databases. Trials enrolling patients with chronic hepatitis C infection treated with DAAs with or without ribavirin were included. Two investigators independently evaluated the trials for inclusion criteria, risk of bias and data extraction. The primary outcome was sustained virological response (SVR). In total, 323 references were identified, and 29 met the inclusion criteria: 18 general clinical trials, three general observational studies, three studies in patients with decompensated liver cirrhosis and four studies in HIV–HCV‐coinfected patients. Overall, 4068 genotype 3 patients were included. As compared with sofosbuvir and ribavirin for 24 weeks, sofosbuvir/velpatasvir for 12 weeks or sofosbuvir plus daclatasvir plus ribavirin for 12 weeks provided higher SVR rates, particularly in patients with cirrhosis. Treatment of patients with decompensated cirrhosis remains a great challenge. Sofosbuvir/ledipasvir+ribavirin for 12 weeks were associated with an SVR of 85% in these patients. In summary, treatment of HCV genotype 3 patients is improving rapidly, and this population may no longer be considered a difficult‐to‐treat subgroup in the near future.     

直接抗病毒药物治疗慢性丙型肝炎的作用机制

近年来随着直接抗病毒药物(DAAs)在全球的研发上市,慢性丙型肝炎的治疗方案不断演化,DAAs在我国也即将上市。DAAs主要作用于HCV的非结构蛋白,抑制HCV RNA的复制。介绍了各类DAAs的作用靶位、作用机制、耐药特性以及在中国的研发现状和临床Ⅲ期试验结果,旨在为慢性丙型肝炎DAAs联合其他抗病毒治疗方案提供临床参考。     

慢性丙型肝炎抗病毒治疗研究的进展

丙型肝炎是由HCV引起的一种主要经血液传播的慢性进展性肝脏疾病.据世界卫生组织统计,全球HCV感染率约为3％,估计约1.7 ～2.0亿人感染了HCV,每年新发丙型肝炎病例约为3.5万例[1,3].HCV感染后约50％～85％转化为慢性感染[4-5].HCV慢性感染可导致肝脏慢性炎症坏死及纤维化,部分患者可发展为肝硬化甚至肝细胞癌,对患者的健康及生命危害极大,已成为严重的社会和公共卫生问题[5-7].HCV感染后的疾病进展与HCV的病毒复制活跃有密切关系,经有效的抗病毒治疗后能控制病毒的复制和肝脏的炎症活动,并阻断疾病的进展,可减少急性丙型肝炎向慢性丙型肝炎发展的概率,也可减少慢性丙型肝炎转为肝硬化和肝癌的可能性[8-10].慢性丙型肝炎抗病毒的治疗目标是清除体内HCV.治疗后能获得持续病毒学应答(sustained virological response,SVR)者,99％可达到临床治愈的目标[11,12].因此,抗病毒治疗是治疗丙型肝炎的关键措施.只要没有干扰素使用的禁忌证,所有的丙型肝炎患者均应进行抗病毒治疗.近来年,慢性丙型肝炎抗病毒治疗有较大的进展,现从三个方面介绍如下:     

Impact of direct‐acting antiviral agents on liver function in patients with chronic hepatitis C virus infection

Whilst the benefit of direct‐acting antiviral agents (DAAs) in achieving sustained virological response (SVR) is now well‐accepted, their impact on liver function, particularly in relation to achievement of SVR, has not been well documented. We studied 2394 patients with chronic HCV infection, 1276 receiving DAAs and 1118 interferon‐based therapy. Liver function was assessed by the albumin‐bilirubin (ALBI) score or grade. Overall survival according to SVR status and baseline ALBI grade was examined. We also studied time to first decompensation according to ALBI grade, as well as longitudinal changes in ALBI score over time according to SVR. Among the patients receiving DAAs, 89% achieved SVR (Japan = 99%, UK = 78%). Amongst the decompensated patients in the UK cohort, three distinct risk groups according to ALBI grade at baseline were observed. The UK patients receiving DAAs, who had predominantly decompensated disease, showed clear evidence of improvement of liver function detectable within 2 years of the start of treatment, especially in those achieving SVR. These early changes in liver function were very similar to those observed in the first 2‐3 years after interferon‐based therapy. DAAs improve liver function especially in those with decompensated disease who achieve SVR. Experience with interferon‐based therapy suggests that failure to achieve SVR is associated with long‐term decline in liver function and, in contrast, patients who do achieve SVR can expect long‐term disease improvement and subsequent stabilization of liver function. Our initial analysis suggests that those receiving DAAs are likely, in the long term, to follow a similar course.     

直接抗病毒药物对儿童慢性丙型肝炎的治疗进展

聚乙二醇干扰素α-2a或α-2b联合利巴韦林是目前治疗儿童慢性丙型肝炎的标准方案。该方案最早应用于成人,对HCV的有效率仅约50%,并且对于儿童HCV的治疗有效率最高也只达70%。近年来,直接作用于HCV基因靶点的抗病毒药物(direct-acting antiviral agents,DAAs)不断被研发出来,对HCV的治疗起到质的飞跃,但该类药物在儿童HCV治疗中的应用大多处在临床试验阶段。本文通过对目前DAAs在儿童慢性丙型肝炎中的研究进展作一综述,以期为HCV患儿的临床治疗提供参考依据。     

Dynamics of liver stiffness by transient elastography in patients with chronic hepatitis C virus infection receiving direct‐acting antiviral therapy—Results from the German Hepatitis C‐Registry

The impact of direct‐acting antiviral (DAA) therapies on fibrosis regression remains uncertain. In the current study, we prospectively evaluated dynamics of liver stiffness by transient elastography (TE) in patients with chronic HCV infection receiving DAA‐based treatment. Patients (260) were enrolled in the German Hepatitis C‐Registry (DHC‐R), a national multicentre real‐world cohort. Liver stiffness (LS) was assessed at baseline, end of treatment (EOT) and 24 weeks after EOT (FU24) by TE. Biochemical, virological and clinical data were obtained in parallel. In patients with SVR, there was a significant improvement of LS between baseline (median [range], 8.6 [1.7‐73.5] kPa) and FU24 (7.9 [1.7‐75 kPa]; P < .0001) as well as between EOT (8.4 [1.7‐73.5 kPa]) and FU24 [P < .0001]. Stratified by fibrosis stage, patients classified into F4 had higher magnitude of LS reduction between BL (median [range], 25.1 [13.5‐73.5] kPa) and FU24 (21.5 [3.1‐75] kPa; P = .002) compared to those with F2‐F3 (8.9 [7.1‐12.4] kPa and 8.8 [4.2‐29.1]; P = .060) or F0‐F1 (5.3 [1.7‐7] kPa and 5.2 [1.7‐7.7]; P = .064). In cirrhotic patients, low platelets were significantly associated with lack of liver stiffness improvement, both at EOT (P = .018) and at FU24 (P = .012). LS significantly correlated with ALT (r = .371), AST (r = .552), platelets (r = ?.499), GGT (r = .250), bilirubin (r = .230), APRI score (r = .512), FIB‐4 score (r = .517) and FORNS index (r = .562); P < .0001. Liver elastography improved significantly in our real‐world cohort after DAA‐based therapy. As LS correlates similarly with transaminase levels and serum fibrosis markers, it might reflect both reduction of necroinflammation and fibrosis regression.     

Low incidence of hepatitis B virus reactivation and subsequent hepatitis in patients with chronic hepatitis C receiving direct‐acting antiviral therapy

To determine the clinical characteristics of hepatitis B virus (HBV) reactivation in patients undergoing interferon‐free antihepatitis C virus (HCV) therapy, we examined HBV DNA in 25 HBV co‐infected patients and 765 patients with resolved HBV infection during and after treatment with direct‐acting antiviral agents (DAAs). Among those with HCV genotype 1, asunaprevir plus daclatasvir was administered to 160 patients, sofosbuvir (SOF) plus ledipasvir to 438 patients and paritaprevir plus ombitasvir and ritonavir to 25 patients. In total, 167 patients with genotype 2 were treated with SOF plus ribavirin. Three patients with an HBV DNA level ≥2000 IU/mL were treated with entecavir before anti‐HCV therapy, without reactivation of HBV. In 3 of 22 (12%) HBV surface antigen (HBsAg)‐positive patients with an HBV DNA level <2000 IU/mL, the viral load increased during treatment. However, hepatitis flare did not occur in these patients. There was no significant difference in clinical history between patients with and without HBV reactivation. Among 765 patients with resolved HBV infection, HBV reactivation occurred in 1 (0.1%) patient after initial resolution, whose HBV DNA level spontaneously decreased after DAA therapy. We compared anti‐HBs titres at baseline with those at post‐DAA therapy in 123 patients without HBsAg. There was no significant difference in anti‐HBs levels between the two points (P = .79). In conclusion, HBV reactivation was rare in HBsAg‐negative patients treated with DAA therapy. Additionally, hepatitis did not occur in HBV‐reactivated patients with a baseline HBV DNA level <2000 IU/mL before DAA therapy.     

不同直接抗病毒药物方案对基因1b型慢性丙型肝炎及代偿期丙型肝炎肝硬化临床结局的影响

目的探讨不同直接抗病毒药物(DAAs)对基因1b型慢性丙型肝炎(CHC)及丙型肝炎代偿期肝硬化(CLC)临床结局的影响。方法以2018年1月-2018年12月就诊于山西医科大学第一医院感染科门诊的115例基因型1b型CHC(n=91)及CLC(n=24)患者为研究对象。所有患者根据病情均采用DAAs抗病毒治疗,CHC患者中28例采用索磷布韦联合维帕他韦方案,21例采用艾尔巴韦格拉瑞韦片方案,16例采用奥比帕利联合达塞布韦方案,13例采用索磷布韦联合达拉他韦方案,13例采用索磷布韦联合利巴韦林方案;CLC患者中15例采用索磷布韦联合维帕他韦方案,4例采用艾尔巴韦格拉瑞韦片方案,5例采用索磷布韦联合达拉他韦方案。分析2组患者的肝功能复常率及病毒学应答率,并观察药物的不良反应。计量资料组间比较采用t检验,计数资料组间比较采用χ^2检验。结果90.4%的患者在治疗1周时获得超快速病毒学应答,98.2%的患者在治疗4周时获得快速病毒学应答,100%的患者在治疗12周时获得完全早期病毒学应答,100%的患者在治疗结束后12周获得持续病毒学应答;不同抗病毒治疗方案在治疗1周、4周时HCV RNA阴转率差异均无统计学意义(χ^2值分别为2.83、0.07,P值均>0.05)。不同抗病毒方案均可明显改善患者肝功能(ALT和AST复常率),不同组间疗效差异均无统计学意义(χ^2值分别为0.83、1.23,P值均>0.05)。DAAs治疗12周后,2组患者肾功能指标与治疗前相比未见有明显升高或降低,差异均无统计学意义(t值分别为1.32、0.56,P值均>0.05)。不良事件的发生率较低,恶心2例(1.74%),头晕、心悸、皮疹、溶血各1例(0.87%)。结论根据病情采用相应DAAs抗病毒方案治疗1b型患者,均可取得较好的病毒学应答率,肝功能改善显著、不良事件的发生率低。     

Long-term cohort study of chronic hepatitis C according to interferon efficacy

Background and Aim: We investigated the prognosis of patients with C‐viral chronic liver disease (C‐CLD) according to the efficacy of interferon (IFN) therapy in a long‐term retrospective cohort study. Methods: Of 721 patients with C‐CLD who underwent liver biopsy between January 1986 and December 2005, 577 were treated with IFN, and 221 of these patients achieved sustained virological response (SVR) with a follow‐up period of 9.9 ± 5.3 years. Results: The annual rate of HCC development was 2.71%/year, 2.31%/year, and 0.24%/year in untreated, non‐SVR, and SVR patients, respectively. Multivariate Cox proportional regression analysis showed that the risk of HCC development was significantly lower in SVR patients than in untreated or non‐SVR patients; moreover, this risk was similar in non‐SVR patients and untreated patients. The annual mortality rate in overall death was 3.19%/year, 1.98%/year, and 0.44%/year in untreated, non‐SVR, and SVR patients, respectively. Multivariate Cox proportional hazards regression analysis showed that the SVR status reduced the risk ratio for overall death to 0.173, whereas the non‐SVR status did not significantly reduce the risk ratio. Conclusions: The risk ratio of overall death and HCC development was significantly reduced in SVR patients, whereas no significant reduction was found in non‐SVR patients in a long‐term cohort study.     

Efficacy and safety of telaprevir, a new protease inhibitor, for difficult-to-treat patients with genotype 1 chronic hepatitis C

The aims of this phase III study were to assess the efficacy and safety of telaprevir in combination with peginterferon alfa-2b (PEG-IFN) and ribavirin (RBV) for difficult-to-treat patients who had not achieved sustained virological response (SVR) to prior regimens in Japan. The subjects were 109 relapsers (median age of 57.0 years) and 32 nonresponders (median age of 57.5 years) with hepatitis C virus genotype 1. Patients received telaprevir (750 mg every 8 h) for 12 weeks and PEG-IFN/RBV for 24 weeks. The SVR rates for relapsers and nonresponders were 88.1% (96/109) and 34.4% (11/32), respectively. Specified dose modifications of RBV that differed from that for the standard of care were introduced to alleviate anaemia. RBV dose reductions were used for 139 of the 141 patients. The SVR rates for relapsers did not depend on RBV dose reduction for 20-100% of the planned dose (SVR rates 87.5-100%, P < 0.05). Skin disorders were observed in 82.3% (116/141). Most of the skin disorders were controllable by anti-histamine and/or steroid ointments. The ratios of discontinuation of telaprevir only or of all the study drugs because of adverse events were 21.3% (30/141) and 16.3% (23/141), respectively. A frequent adverse event leading to discontinuation was anaemia. Telaprevir in combination with PEG-IFN/RBV led to a high SVR rate for relapsers and may offer a potential new therapy for nonresponders even with a shorter treatment period.