Low frequency of NS5A relevant resistance-associated substitutions to Elbasvir among hepatitis C virus genotype 1a in Spain: a cross-sectional study

Treatment outcomes in hepatitis C virus genotype 1a infected patients with and without baseline NS5A resistance-associated substitutions

BACKGROUND&AIMS

The presence of baseline resistance-associated substitutions (RASs) reduced sustained virologic response (SVR) rates in chronic hepatitis C virus (HCV) genotype 1a infected patients treated with Elbasvir/Grazoprevir (EBR/GZR). This study aimed to evaluate the frequency of NS5A RASs and treatment outcomes in patients for whom EBR/GZR was intended.

METHODS

We sequenced NS5A in 832 samples from German genotype1a-infected DAA-naïve patients population-based, which were collected in the European Resistance Database. Treatment outcomes and clinical parameters were evaluated in 519 of these patients retrospectively.

RESULTS

Overall, 6.5% of patients harbored EBR-specific NS5A RASs at baseline, including Q30H/R (3.3%), L31M (1.8%), Y93H (1.6%) and other individual variants. Antiviral treatment, including EBR/GZR, was initiated in 88% of patients. In the absence of RASs, the majority of patients received EBR/GZR for 12 weeks (57%) and the SVR rate was 97% compared to 99% SVR achieved using other DAA regimens (LDV/SOF±RBV, G/P, PrOD+RBV, VEL/SOF). Various regimens were used in the presence of RASs and SVR rates were high following treatment with LDV/SOF (100%), G/P (83%), PrOD/RBV (100%), VEL/SOF (100%), SMV/SOF (100%) and EBR/GZR+RBV for 16 weeks (100%). However, two patients received EBR/GZR for 16 weeks without RBV and one relapsed.

CONCLUSIONS

EBR/GZR treatment with or without RBV for 12 or 16 weeks according to a baseline RAS analysis was highly effective with ≥97% SVR in patients with genotype 1a. EBR/GZR without RBV should be avoided in patients with RASs. High SVR rates were also achieved using other 8 or 12 weeks DAA regimens.

Pre-treatment antiviral resistance in Australians with chronic hepatitis C: prevalence of NS3 and NS5A resistance data in the state of New South Wales

BACKGROUND

Direct-acting antivirals (DAAs) have revolutionized HCV treatment, but the impact of antiviral resistance at a population level is still not clear. The majority of patients who fail DAA therapy develop resistance-associated substitutions (RASs), which can impact re-treatment. There is potential for resistance prevalence to rise in the community with treatment scale up, due to transmission of resistant virus. Monitoring for increasing antiviral resistance requires a reliable baseline, yet there are few published data on the prevalence of HCV resistance in Australia. The aim of this study was to determine the prevalence of RASs among untreated Australians with HCV genotype-1a infection, to inform ongoing surveillance.

METHODS

A cross-sectional study was performed at a single large university hospital pathology laboratory in Australia. Archived blood samples referred for HCV genotype testing were analysed. All patients were naive to DAAs. The prevalence of RASs in the HCV NS3 and NS5A regions was determined using Sanger based population sequencing.

RESULTS

Of 379 samples tested, 34% contained DAA-resistant virus: 24% had resistance to NS3 protease inhibitors, 12% had NS5A inhibitor resistance and 4% of patients had resistance to both drug classes. Clinically relevant RASs conferring resistance against NS5A inhibitors ledipasvir, daclatasvir and elbasvir were detected in 5.8% of samples.

CONCLUSIONS

This is the largest study of HCV antiviral drug resistance in Australia, which differs from resistance prevalence in the USA. The results provide valuable data on the baseline prevalence of HCV resistance, which can be used in the future to monitor for increasing antiviral resistance.

Rescue therapy for chronic hepatitis C virus infection after repeated treatment failures: Impact on disease progression and risk of hepatocellular carcinoma

AIM

Retreatment after previous failure of direct-acting antivirals for hepatitis C virus (HCV) infection is a challenging decision. The importance of achieving viral eradication on modification of disease progression and outcome, including the risk of hepatocellular carcinoma (HCC), remains a critical issue to be evaluated.

METHODS

One hundred patients with repeated failure of sofosbuvir and ribavirin or triple therapy with sofosbuvir, ribavirin, and daclatasvir were divided into a study group (n = 50) given rescue therapy (sofosbuvir, daclatasvir, simeprevir, and ribavirin) or a control group (n = 50) matched for age, sex, and pretreatment variables (Child-Turcotte-Pugh score and Fibrosis-4 score). Follow-up was undertaken after the last non-response to detect serious adverse events, such as hepatic decompensation and development of HCC.

RESULTS

The study group achieved sustained virologic response (SVR) in 47 of 50 (94%) patients. The control group had significantly higher HCC rates than the study group (7 vs. 1 patients), with an odds ratio of 5.44. The rescue therapy was associated with significantly longer time to the occurrence of adverse events. Repeated treatment failures were associated with progression of FibroScan values in the control group (21 ± 4.5 vs. 10 ± 1.5 kPa, P = 0.001); achieving SVR in the study group stopped fibrosis progression despite non-significant increase from baseline (13.2 ± 3.2 vs. 10.6 ± 0.6, P = 0.12).

CONCLUSIONS

Rescue treatment for HCV infection was highly effective in achieving SVR, less expensive than the newer agents, and is associated with diminished risk of serious adverse events, mainly HCC in these patients.

Rescue Therapy for Genotype-3 DAA Non-responders, Almost all Done

Nowadays, the retreatment of patients with Hepatitis C virus (HCV) genotype 3 (GT3) especially cirrhotic, who have already been treated with regimens containing a NS5A inhibitor represents a challenge. Use a novel retreatment option for patients with a difficult approach. We present three case reports of retreatment with a new combination of Direct-acting antivirals (DAAs), Sofosbuvir, Elbasvir/Grazoprevir in patients with GT3 with a previous failure with Sofosbuvir/Ledipasvir. All the cases achieved sustained virologic response (SVR) at week +12 without adverse effects. In our experience, this combo may represent an effective and safe option for these patients.

Effectiveness and safety of elbasvir/grazoprevir therapy in patients with chronic HCV infection: Results from the Spanish HEPA-C real-world cohort

In randomized controlled trials of patients with chronic HCV infection, elbasvir/grazoprevir (EBR/GZR) demonstrated high cure rates and a good safety profile. This study assessed the effectiveness and safety of EBR/GZR, with and without ribavirin, in a real-world HCV patient cohort. HEPA-C is a collaborative, monitored national registry of HCV patients directed by the Spanish Association for the Study of the Liver and the Networked Biomedical Research Centre for Hepatic and Digestive Diseases. Patients entered into HEPA-C between December 2016 and May 2017, and treated with EBR/GZR with at least end-of-treatment response data, were included. Demographic, clinical and virologic data were analysed, and adverse events (AEs) recorded. A total of 804 patients were included in the study. The majority were male (57.9%), with a mean age of 60 (range, 19-92) years. Genotype (GT) distribution was GT 1, 86.8% (1a, 14.3%; 1b, 72.5%); GT 4, 13.2% and 176 patients (21.9%) were cirrhotic. Overall, among 588 patients with available data, 570 (96.9%) achieved sustained virologic response at 12 weeks post-treatment (SVR12). SVR12 rates by genotype were GT 1a, 97.7%; GT 1b, 98.6%; and GT 4, 98.1%. No significant differences in SVR12 according to fibrosis stage were observed. Eighty patients experienced an AE, resulting in treatment discontinuation in three. In this large cohort of patients with chronic HCV managed in a real-world setting in Spain, EBR/GZR achieved high rates of SVR12, comparable to those observed in randomized controlled trials, with a similarly good safety profile.

Baseline resistance-guided therapy does not enhance the response to interferon-free treatment of HCV infection in real life

Hepatitis C virus (HCV) response to direct-acting antivirals (DAAs) may be influenced by the presence of resistance-associated substitutions (RASs). This study aimed to assess if NS5A baseline RAS-guided treatment enhances the rate of sustained viral response (SVR) in naïve HCV-infected patients in clinical practice. All HCV-infected patients who initiated treatment with interferon (IFN)-free DAA-based regimens between March 2016 and May 2017 in 17 Spanish hospitals and who had evaluable SVR 12 weeks (SVR12) after the end of therapy were included. Patients had to be DAA naïve, with the exception of sofosbuvir with/without IFN. In one hospital, participants received therapy guided by the presence of NS5A-RASs (RGT population). Patients enrolled in the remaining hospitals, without baseline RASs testing, constituted the control population. A total of 120 and 512 patients were included in the RGT and control populations, respectively. Nine (7.5%) individuals in the RGT population showed baseline NS5A-RASs. All of them achieved SVR12. The SVR12 rate in the RGT population was 97.2% (three relapses) whereas it was 98.8% (six relapses) in the control population (p = 0.382). Our findings suggest that testing for baseline NS5A-RASs in naïve HCV-infected patients does not enhance the rate of SVR to DAA-based IFN-free therapy in clinical practice.

Epidemic history of hepatitis C virus genotypes and subtypes in Portugal

Any successful strategy to prevent and control HCV infection requires an understanding of the epidemic behaviour among the different genotypes. Here, we performed the first characterization of the epidemic history and transmission dynamics of HCV subtypes in Portugal. Direct sequencing of NS5B was performed on 230 direct-acting antiviral drugs (DAA)-treatment naïve patients in Lisbon. Phylogenetic analysis was used for subtyping and transmission cluster identification. Bayesian methods were used to reconstruct the epidemic history of HCV subtypes. Sequences were analysed for resistance-associated substitutions (RAS). The majority of strains were HCV-GT1 (62.6%), GT3 (18.3%, all subtype 3a) and GT4 (16.1%). Among GT1, the most frequent were subtypes 1a (75.5%) and 1b (24.5%). Polyphyletic patterns were found in all but 12 lineages suggesting multiple introductions of the different subtypes in this population. Five distinct epidemics were identified. The first significant HCV epidemic in Portugal occurred between 1930s and 1960s, was caused almost exclusively by GT1b and was likely associated with blood transfusions. Rapid expansion of GT3a occurred in the 1960s and GT1a in the 1980s, associated with intravenous drug use. The most recent epidemics were caused by GT4a and GT4d and seem to be associated with the resurgence of opioid use. The C316N substitution was found in 31.4% of GT1b-patients. Close surveillance of patients bearing this mutation and undergoing dasabuvir-based regimens will be important to determine its impact on treatment outcome.