Safety and efficacy of sofosbuvir-based direct-acting antiviral regimens for hepatitis C virus genotypes 1-4 and 6 in Myanmar: Real-world experience

'Unusual' HCV genotype subtypes: origin, distribution, sensitivity to direct-acting antiviral drugs and behaviour on antiviral treatment and retreatment

The high genetic diversity of hepatitis C virus (HCV) has led to the emergence of eight genotypes and a large number of subtypes in limited geographical areas. Currently approved pangenotypic DAA regimens have been designed and developed to be effective against the most common subtypes (1a, 1b, 2a, 2b, 2c, 3a, 4a, 5a and 6a). However, large populations living in Africa and Asia, or who have migrated from these regions to industrialised countries, are infected with 'unusual', non-epidemic HCV subtypes, including some that are inherently resistant to currently available direct-acting antiviral (DAA) drugs due to the presence of natural polymorphisms at resistance-associated substitution positions. In this review article, we describe the origin and subsequent global spread of HCV genotypes and subtypes, the current global distribution of common and unusual HCV subtypes, the polymorphisms naturally present in the genome sequences of unusual HCV subtypes that may confer inherently reduced susceptibility to DAA drugs and the available data on the response of unusual HCV subtypes to first-line HCV therapy and retreatment. We conclude that the problem of unusual HCV subtypes that are inherently resistant to DAAs and its threat to the global efforts to eliminate viral hepatitis are largely underestimated and warrant vigorous action.

Real-world treatment outcomes of sofosbuvir-based regimens for treatment of chronic hepatitis C with and without human immunodeficiency virus co-infection

Background and Aim

The efficacy of sofosbuvir (SOF)-based regimens in the treatment of chronic hepatitis C (HCV) patients with and without human immunodeficiency virus (HIV) co-infected patients in real-world setting is limited.

Methods

This was a retrospective cohort study, conducted between 1 January 2017 and 31 December 2021 at Bamrasnaradura Infectious Disease Institute, Thailand. All HCV patients received 12 weeks of SOF-based regimens and had follow-up for at least 12 weeks after therapy discontinuation. The primary outcome was sustained virological response (SVR) at 12 weeks after the end of treatment. Treatment outcomes were compared between HCV patients with and without HIV co-infection.

Results

A total of 163 patients were included in the study, 130 (79.8%) were HCV/HIV co-infected, and 33 (20.2%) were HCV mono-infected. Of all, 106 (64%) patients received SOF and ledipasvir. Genotype 1 (GT1) was predominant at 66.4%, followed by GT3 at 22.2%, and GT6 at 11.4%. Overall SVR was 96.9%. SVR in HCV mono-infected was 96.9% and SVR in HIV-HCV co-infected patients was 96.9%. The factor associated with SVR was HCV genotype (P = 0.001). Patients with HCV GT6 had lower SVR rates compared with GT1 and GT3 patients (83.3%, 100%, and 97.1% [P = 0.000] respectively). There was no association between SVR and other factors such as gender, age, BMI, underlying cirrhosis, baseline HCV viral load, or prior treatment history (all P > 0.05). All patients completed 12-week SOF-based treatment.

Conclusion

In real-world setting, HCV treatment with SOF-based regimens between patients with and without HIV co-infection showed high rates of SVR. SOF-based regimens were highly efficacious and tolerated.

The art of managing hepatitis C virus in special population groups: a paradigm shift

The first direct-acting antiviral (DAA) medications were approved for the treatment of chronic hepatitis C virus (HCV) in 2011. Later, the appearance of novel DAAs had revolutionized the landscape of HCV treatment whose early treatment options were limited to interferon (IFN) either alone or in combinations. This review discusses the paradigm shift in legibility for treating different groups of patients with HCV after the introduction of DAAs, along with the consequent changes in treatment guidelines. IFN-based therapy was the firstly used for treating chronic HCV. Unfortunately, it exhibited many pitfalls, such as low efficacy in some patients and unsuitability for usage in lots of patients with some specific conditions, which could be comorbidities such as autoimmune thyroiditis, or liver related as in decompensated cirrhosis. Furthermore, IFN failed to treat all the extrahepatic manifestations of HCV. Nowadays, the breakthroughs brought by DAAs have benefited the patients and enabled the treatment of those who could not be treated or did not usually respond well to IFN. DAAs achieve a high success rate of HCV eradication in addition to avoiding unfavorable harms and, sometimes, adverse effects related to the previously used PEGylated IFN regimens.

Determining the lower limit of detection required for HCV viral load assay for test of cure following direct-acting antiviral-based treatment regimens: Evidence from a global data set

Achieving global elimination of hepatitis C virus requires a substantial scale-up of testing. Point-of-care HCV viral load assays are available as an alternative to laboratory-based assays to promote access in hard to reach or marginalized populations. The diagnostic performance and lower limit of detection are important attributes of these new assays for both diagnosis and test of cure. Therefore, our objective was to determine an acceptable LLoD for detectable HCV viraemia as a test for cure, 12 weeks post-treatment (SVR12). We assembled a global data set of patients with detectable viraemia at SVR12 from observational databases from 9 countries (Egypt, the United States, United Kingdom, Georgia, Ukraine, Myanmar, Cambodia, Pakistan, Mozambique) and two pharmaceutical-sponsored clinical trial registries. We examined the distribution of HCV viral load at SVR12 and presented the 90th, 95th, 97th and 99th percentiles. We used logistic regression to assess characteristics associated with low-level virological treatment failure (defined as <1000 IU/mL). There were 5973 cases of detectable viraemia at SVR12 from the combined data set. Median detectable HCV RNA at SVR12 was 287,986 IU/mL. The level of detection for the 95th percentile was 227 IU/mL (95% CI 170-276). Females and those with minimal fibrosis were more likely to experience low-level viraemia at SVR12 compared to men (adjusted odds ratio AOR = 1.60 95% confidence interval [CI] 1.30-1.97 and those with cirrhosis (AOR = 1.49 95% CI 1.15-1.93). In conclusion, an assay with a level of detection of 1000 IU/mL or greater may miss a proportion of those with low-level treatment failure.

Characterization of a Novel Hepatitis C Subtype, 6xj, and Its Consequences for Direct-Acting Antiviral Treatment in Yunnan, China

Hepatitis C virus (HCV) has a high rate of genetic variability, with eight genotypes and 91 subtypes. The genetic diversity of HCV genotype 6 (HCV-6) is the highest with 31 subtypes, and this genotype is prevalent in Southeast Asia. In this study, we investigated 160 individuals with chronic hepatitis C in Yunnan Province, China. Using reverse transcription (RT)-PCR and Sanger sequencing, 147 cases were successfully amplified and genotyped as 3b (4.9%), 3a (19.73%), 6n (12.24%), 1b (7.48%), 2a (6.12%), 6a (2.04%), 1a (0.68%), 6v (0.68%), and 6xa (0.68%), with eight sequences remaining unclassified. Subsequently, the eight nearly full-length genomes were successfully amplified and analyzed. The eight complete coding sequences formed a phylogenetic group that was distinct from the previously assigned HCV-6 subtypes and clustered with two previously unnamed HCV-6 sequences. Furthermore, Simplot analysis showed no recombination and the p-distance was more than 15% in comparison to the 6a to 6xi subtypes. Taken together, we identified a new HCV-6 subtype, 6xj, which originated approximately in 1775 according to Bayesian analyses. Moreover, all eight individuals received follow-up assessments at 44 weeks from the beginning of their 12-week treatments of sofosbuvir/velpatasvir (after-treatment week 32). One case relapsed at after-treatment week 32. Next-generation sequencing (NGS) was conducted and showed that the treatment failure case had two suspected antiviral resistance mutations, NS5A V28M (a change of V to M at position 28) and NS5B A442V, compared with the baseline. Overall, this newly identified 6xj subtype further confirmed the high diversity of the HCV-6 genotype. The newly identified resistance-associated amino acid substitutions may help inform future clinical treatments. IMPORTANCE This study investigated the genetic diversity of hepatitis C virus (HCV), particularly in relation to genotype 6, which is prevalent in Yunnan, China, and is often difficult to treat successfully. We identified a new HCV-6 subtype, 6xj, which is an ancient strain. Moreover, all eight individuals with the novel subtype received follow-up assessments at 44 weeks from the beginning of their treatments. One case relapsed after 8 months of withdrawal. NGS was conducted and showed that the isolate from the treatment failure case had two suspected antiviral resistance mutations, NS5A V28M and NS5B A442V, compared with the baseline. Overall, this newly identified 6xj subtype further confirmed the high diversity of the HCV-6 genotype. The newly identified resistance-associated amino acid substitutions may help inform future clinical treatments. We believe that our study makes a significant contribution to the literature based on the results described above.

Efficacy and safety of glecaprevir/pibrentasvir in patients with HCV genotype 5/6: An integrated analysis of phase 2/3 studies

BACKGROUND & AIMS

Hepatitis C virus (HCV) has high genetic diversity with six major genotypes (GT) GT1-6 and global distribution. HCV GT5 and 6 are rare with < 10 million people infected worldwide. Data on direct-acting antiviral use in these rare HCV genotypes are limited. The study aimed to evaluate the efficacy and safety of glecaprevir/pibrentasvir (G/P) in a pooled analysis of phase 2/3 trials in HCV GT5 or 6-infected patients without cirrhosis or with compensated cirrhosis.

METHODS

Patients with chronic HCV GT5 or 6 infection received oral G/P (300 mg/120 mg) once daily for 8 or 12 weeks. The primary efficacy endpoint was sustained virological response at post-treatment week 12 (SVR12) in the intention-to-treat population.

RESULTS

One hundred eighty-one patients were evaluated; 56 with HCV GT5 and 125 with HCV GT6. The majority were treatment-naïve (88%) and non-cirrhotic (85%). Overall SVR12 rate with 8- or 12-week G/P treatment was 98% (178/181). Eight-week treatment with G/P yielded SVR12 rates of 95% (21/22) in HCV GT5- and 99% (69/70) in HCV GT6-infected non-cirrhotic patients. Eight- and 12-week treatment of patients with compensated cirrhosis achieved SVR12 rates of 100% (10/10) and 94% (17/18) respectively. The G/P regimen was well-tolerated; 3% (6/181) Grade 3 or higher adverse events, and no serious adverse events were attributed to G/P or led to study drug discontinuation.

CONCLUSIONS

This integrated dataset demonstrates a high SVR12 rate following 8-week G/P treatment in patients with HCV GT5 (96%) or GT6 (99%) infection without cirrhosis or with compensated cirrhosis.

Effectiveness of sofosbuvir based direct-acting antiviral regimens for chronic hepatitis C virus genotype 6 patients: Real-world experience in Vietnam

Background

Hepatitis C virus (HCV) genotype 6 is the commonest cause of chronic hepatitis C infection in much of southeast Asia, but data on the effectiveness of direct-acting antiviral agents (DAAs) against this genotype are limited. We conducted a retrospective cohort study of patients attending the Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam, to define the effectiveness of DAAs in the treatment of chronic HCV genotype 6 in actual practice.

Methods

We included all patients with genotype 6 infections attending our hospital between March 2016 and October 2017 who received treatment with sofosbuvir-based DAA treatment regimens, and compared their responses with those with genotype 1 infections.

Results

1758 patients (1148 genotype 6, 65.4%; 610 genotype 1, 34.6%) were analyzed. The majority of patients (1480, 84.2%) received sofosbuvir/ledipasvir (SOF/LDV) ± ribavirin (RBV); 278 (15.8%) received sofosbuvir/Daclatasvir (SOF/DCV) ± RBV. The median age of the patients was 57 years, (interquartile range (IQR) 46–64 years) The baseline HCV viral load (log IU/ml) was significantly higher in patients infected with genotype 6 compared with those infected with genotype 1 (6.8, 5.3–6.6 versus 6.3, 5.3–6.5 log10 IU/ml, p = <0.001, Mann Whitney U test). A sustained virological response (SVR), defined as an undetectable viral load measured between 12 and 24 weeks after completing treatment, and indicating cure, was seen in 97.3% (1711/1758) of patients. Treatment failure, defined as HCV viral load ≥15 IU/ml ≥12 weeks after completing treatment appeared to be more frequent in patients infected with genotype 6 virus (3.2%, 37/1148) than in those infected with genotype 1 (1.7%, 10/610), p = 0.050 chi-squared test). We found no evidence that patient’s age, gender, liver cirrhosis, diabetes, HBV or HIV coinfection, prior treatment failure with pegylated interferon therapy, body mass index (BMI), aspartate aminotransferase to platelet ratio index (APRI), or fibrosis 4 (FIB-4) index were associated with treatment failure.

Conclusions

Our study suggests that patients with HCV genotype 6 infection in Vietnam may respond less well to treatment with sofosbuvir based DAAs than patients with genotype 1 infections. Further studies are needed to confirm this observation and to define whether it is driven by genotype-specific mutations.

Prevalence of Hepatitis C Virus in an Endemic Area of Thailand: Burden Assessment toward HCV Elimination

Chronic hepatitis C virus (HCV) infection can lead to liver cirrhosis and hepatocellular carcinoma. To eliminate HCV infection in an endemic area, an epidemiological baseline of the current HCV infection in the population is required. We therefore aimed to evaluate the HCV burden in the Thai Province of Phetchabun, which has the highest HCV infection rate in the country. Toward this, a province-wide district-based representative sampling of 4,769 individuals ages 35-64 years previously shown to represent high-risk age-groups were tested for anti-HCV antibodies using the automated chemiluminescent microparticle assays. Active HCV infection and subsequent genotyping were determined from serologically reactive samples by amplification of the HCV core gene. We found that 6.9% (327/4,769) were anti-HCV positive, of which 75.8% (248/327) had detectable HCV RNA and 5.8% (19/327) were in the presence of hepatitis B virus coinfection. Nucleotide sequencing and phylogenetic analysis revealed that HCV genotype 6 was the most prevalent (41%, 101/248), followed by genotype 3 (31%, 78/248), and genotype 1 (28%, 69/248). Socioeconomic and demographic factors including male gender, education, and agricultural work were associated with HCV seropositivity. From these results, we defined the regional HCV genotypes and estimated the HCV burden necessary toward the implementation of pan-genotypic direct-acting antivirals, which may be appropriate and effective toward the diversity of genotypes identified in this study. Micro-elimination of HCV in Phetchabun may serve as a model for a more comprehensive coverage of HCV treatment in Thailand.

Real-world effectiveness and safety of ledipasvir/sofosbuvir for genotype 6 chronic hepatitis C patients in Taiwan

BACKGROUND AND AIM

Infection with hepatitis C virus (HCV) genotype (GT) 6 is uncommon in Taiwan, and reports of ledipasvir/sofosbuvir (LDV/SOF) treatment for GT6 are few. This study evaluates the effectiveness and safety of LDV/SOF in treating chronic hepatitis C (CHC) patients with GT6 infection.

METHODS

CHC patients that were infected with GT6 and treated for 12 weeks with LDV/SOF at two hospitals were enrolled. All patients were followed for an additional 12 weeks after the completion of LDV/SOF treatment. Demographics, HCV viral load, lipid and sugar profiles, and adverse events were recorded and reviewed.

RESULTS

A total of 127 patients were enrolled. Cirrhosis was found in 68.2% of them. Sustained virological response (SVR), determined by per-protocol analysis, was 97.6%. The SVR rates for cirrhosis versus non-cirrhosis (96.5% vs 100%, P = 0.229) and low versus high viral load (cutoff value: 10⁶  IU/mL; 100% vs 95.6%, P = 0.108) were similar. Following HCV clearance, significantly lower glycosylated hemoglobin was present both in patients with or without diabetes mellitus. Twenty-three (18.1%) patients exhibited adverse events, and each adverse event presented with an incidence of 0.8% to 3.1%. Neuropsychiatric symptoms were the most common. During treatment, 18 patients (14.2%) had alanine aminotransferase elevations consistent with more than grade 1 abnormalities, and none had signs of decompensation. Renal function remained unchanged.

CONCLUSION

The high SVR and excellent safety of LDV/SOF treatment for GT6 CHC patients suggest that LDV/SOF is a favorable option for treating GT6 CHC patients in Taiwan and Asia.

Sofosbuvir-based regimens in the treatment of patients with chronic hepatitis C virus infection: Real-world efficacy in Thailand

Aims

To analyze the efficacy and safety of sofosbuvir (SOF)-based regimens in Thai patients with chronic hepatitis C virus infection who had pre-existing significant liver fibrosis.

Patients and methods

This was a retrospective cohort study, conducted between 1 June 2018 and 31 May 2019 at Rajavithi Hospital, Bangkok, Thailand. All patients completed 12 weeks of SOF-based regimens and had follow-up for at least 12 weeks after therapy discontinuation. The primary outcome was sustained virological response (SVR) 12 weeks after the end of therapy.

Result

A total of 185 patients were included, with 52, 63 and 70 taking SOF+Ledipasvir (SOF+LDV), SOF+LDV+ribavirin (RBV) and SOF+Pegylated interferon (Peg-IFN)+RBV (SOF+Peg-IFN+RBV) respectively. Genotype (GT) 1 was predominant at 40.0%, followed by GT3 at 37.8%, and GT6 at 22.2%. Overall 95.1% of patients in this study achieved SVR (n = 176/185), and the only factor associated with SVR was HCV genotype (p = 0.001). GT6 patients had lower SVR rates compared to GT1 and GT3 patients (82.9%, 98.6%, and 98.6% respectively) while there was no association between SVR and other factors (p >0.05) such as gender, age, BMI, underlying cirrhosis, baseline HCV viral load, or prior treatment history. No serious adverse events were reported in the present study.

Conclusion

Sofosbuvir-based regimens in the treatment of patients with chronic HCV infection were highly efficacious with excellent safety and tolerability profiles in a real-world setting; however, further research is required to establish whether or not such a regimen is an adequate treatment for all genotype 6 patients.

Strategies for access to affordable hepatitis C testing and treatment in Asia

PURPOSE OF REVIEW

With increasing availability of generic direct-acting antivirals (DAAs) and associated price reductions, various governments, multilateral institutions, and donors have started providing testing and treatment for hepatitis C virus (HCV) infection. More data on the quality of these generic medicines and on cost-effectiveness of their use are becoming widely available. This review seeks to describe some of the treatment programs for HCV that are evolving in Cambodia, India, Indonesia, Malaysia, Myanmar, and Thailand.

RECENT FINDINGS

The quality of multiple generic DAAs has been shown to be bioequivalent to innovator formulations, with generic versions achieving high cure rates in real-world settings. Although published materials are limited, there is expanding experience with local pilot and national treatment programs which are largely being funded by national governments and other institutions.

SUMMARY

Countries and other public health stakeholders are recognizing the need to scale up HCV diagnosis and treatment programs using generic DAAs. However, local pilot or national treatment programs need to be massively expanded to eliminate HCV in high-burden areas.

Pangenotypic direct acting antivirals for the treatment of chronic hepatitis C virus infection: A systematic literature review and meta-analysis

BACKGROUND

Recent approval and adoption of pangenotypic direct acting antivirals (DAAs) necessitated a revision of the 2015 World Health Organization guidelines for the management of persons with hepatitis C virus (HCV) infection.

METHODS

We searched MEDLINE, EMBASE, CENTRAL, and relevant conference proceedings to identify randomized and non-randomized trials, as well as prospective observational studies of DAAs. The proportions of persons with events were pooled for sustained virological response at 12 weeks post-treatment (SVR12), discontinuations due to adverse events (DAEs), serious adverse events (SAEs), and all-cause mortality. Analyses were stratified by HCV genotype and antiviral treatment experience, with subgroup analyses based on presence of cirrhosis and HIV-HCV coinfection.

FINDINGS

The evidence base consisted of 238 publications describing 142 studies. In the overall analysis, which included all persons irrespective of treatment experience or comorbidities, the pooled proportion achieving SVR12 exceeded 0.94 for all pangenotypic regimens across genotypes 1, 2, and 4. Some heterogeneity may have led to lower SVR rates in persons with genotype 3 infection. High SVR12 (>0.90) was observed in persons with genotype 1 infection with cirrhosis, though evidence varied and was limited for genotypes 2-4. Evidence was sparse for persons with HIV-HCV coinfection. All regimens were associated with small proportions of persons with DAEs, SAEs, or all-cause mortality.

INTERPRETATION

Based on this and other supporting evidence, the WHO issued updated guidelines with a conditional recommendation, based on moderate quality evidence, for the use of pangenotypic DAA regimens for persons with chronic HCV infection aged 18 years and older (July 2018).

FUNDING

This study was funded by the World Health Organization.

High sustained virologic response in genotypes 3 and 6 with generic NS5A inhibitor and sofosbuvir regimens in chronic HCV in myanmar

Exclusive HCV therapy clinical trials with genotype 6 patients in high prevalence areas have been sparse. We analysed the safety and efficacy of two generic, pangenotypic NS5A/NS5B combination oral DAA regimens, primarily in genotypes 3 and 6, in a real-world setting: (a) daclatasvir/sofosbuvir (DCV/SOF) ± ribavirin (RBV) and (b) Velpatasvir/sofosbuvir (VEL/SOF ± RBV). Between December 2015 and November 2017, data from 522 patients were analysed, 311 of whom were treated with DCV/SOF ± RBV for 12/24 weeks (genotype 3: n = 193, genotype 6: n = 89) and 211 were treated with VEL/SOF ± RBV for 12/24 weeks (genotype 3: n = 83, genotype 6: n = 77). Overall SVR rates were high for both DCV/SOF ± RBV (96.1%, n = 299/311) and VEL/SOF ± RBV (95.3%, n = 201/211), and there was a good adverse event profile. Treatment naïve status and inclusion of RBV (in advanced fibrosis/cirrhosis) were significant independent predictors of achieving SVR12, while type of DAA regimen was not predictive. In this large cohort of genotypes 3 (n = 276) and 6 (n = 166; n = 127 unique subtype of 6c-l), high SVR rates of 94.9% (n = 262/276) and 95.2% (n = 158/166), respectively, were noted. In conclusion, generic and pangenotypic DCV/SOF and VEL/SOF ± RBV regimens were highly effective and safe, in genotypes 3 and 6 chronic HCV in Myanmar. These efficacious pangenotypic regimens suggest that baseline genotype testing can be eliminated moving forward. While RBV may still be needed for those with advanced fibrosis/cirrhosis, in a global elimination strategy it would not be practical even if it does compromise SVR in a minority with difficult to treat characteristics.

Sofosbuvir-ledipasvir with or without ribavirin for chronic hepatitis C genotype-1 and 6: real-world experience in Vietnam

BACKGROUND

Therapy with sofosbuvir-ledipasvir (SOF-LDV) has been very effective in chronic HCV genotype-1 in clinical trials and several real-world cohorts. However, the safety and efficacy data of SOF-LDV for HCV genotype-6 is quite limited.

METHODS

This open-label, clinical experience evaluated the safety and efficacy of SOF-LDV with or without ribavirin (RBV) for 12-24 weeks in patients with HCV genotype-1 (n=356) and genotype-6 (n=175) in Vietnam between September 2015 and May 2017.

RESULTS

Among 539 patients evaluated for therapy, 531 patients completed treatment with either SOF-LDV for 12 weeks (n=284); SOF-LDV + RBV for 12 weeks (n=109); SOF-LDV for 24 weeks (n=36); or SOF-LDV + RBV for 24 weeks (n=102). 45% were male with a mean age of 56.3 (range 20-87) years. The mean HCV RNA was 4,370,000 IU/ml and 72.7% had high viral load of >800,000 IU/ml. 17.3% failed prior interferon-based therapy and 52.5% had advanced fibrosis (F3-4) as noted by transient elastography. The overall sustained virological response (SVR12) rate was 99.6% (529/531). Virological relapses occurred in two patients with genotype-1 in the SOF-LDV for 12 weeks and SOF-LDV + RBV for 24 weeks treatment groups. There was no significant difference in demographic data and treatment outcomes between patients with genotype-1 versus 6. Adverse events were mild with all SOF-LDV regimens, but appeared to be more common with 24-week treatment groups.

CONCLUSIONS

SOF-LDV with or without RBV was highly effective and safe in Vietnamese patients with HCV genotype-1 and 6.

International Liver Transplantation Society Asian Consensus on the Management of Hepatitis C Virus Infection in Resource Limited Setting-From Noncirrhotic to Decompensated Disease and After Liver Transplantation

BACKGROUND

The population of Asia exceeds 4.4 billion people. Chronic hepatitis C virus (HCV) infection in Asia is characterized by specific distribution of genotypes, lack of access to specific therapeutic agents, relatively high cost of treatment, and lack of experienced healthcare providers. Clear consensus on the diagnosis, management, and monitoring of HCV infection specific to the Asian region is a major unmet need. The consensus guidelines documents that have been published to date by major medical societies presume access to an array of direct acting antiviral agents and diagnostic tests that are not broadly applicable to resource limited settings, including Asia.

METHODS

To address the lack of an Asia-specific set of HCV treatment guidelines, we assembled a panel of 15 HCV experts in the field of hepatology from India, Indonesia, Myanmar, Vietnam, Pakistan, Philippines, and Mongolia convened in April 2017 to review the updated literature and provide recommendations on the diagnosis and management of chronic HCV infection that reflects local conditions.

RESULTS

An evidence-based comprehensive compilation of the literature supported by the graded recommendations from the expert panel for the optimization of the diagnosis, pretreatment, on treatment, and posttreatment assessments, and management of chronic HCV infection has been presented in this article.

CONCLUSIONS

With the evolving treatment landscape and addition of several new direct-acting antiviral agents and combination regimens into the therapeutic armamentarium, the current article may serve as a guide to the clinicians in optimizing the diagnosis and treatment selection for the management of chronic HCV infection in resource-limited settings.

Identification of a New HCV Subtype 6xg Among Injection Drug Users in Kachin, Myanmar

Characterizing hepatitis C virus (HCV) genetic diversity not only allows us to trace its origin and evolutionary history, but also provides valuable insights into diagnosis, prevention and therapy of HCV infection. Although eight HCV genotypes and 86 subtypes have been classified, there are still some HCV variants that need to be assigned. The genotype 6 is the most diverse HCV genotype and mainly prevalent in Southeast Asia. In this study, we identified a new HCV subtype 6xg from injection drug users (IDUs) in Kachin, Myanmar. A distinctive feature of 6xg from other subtypes of the genotype 6 was a Lys insertion in NS5A gene, which changes the RRKR/K motif into RRKKR/K. Bayesian analyses showed that HCV 6xg originated during 1984–1988, and experienced a rapid population expansion during 2005–2009. We characterized HCV subtype profile among IDUs in this region, and detected six HCV subtypes, including 1a (12.0%), 3a (12.0%), 3b (24.0%), 6n (16.0%), 6xa (20.0%), and 6xg (12.0%). Importantly, we found that HCV subtype distribution in Kachin was very similar to that in Dehong prefecture of Yunnan, but very distinct from those in other regions of Myanmar and Yunnan, indicating that the China–Myanmar border region shared a unique HCV subtype pattern. The appearance of 6xg and the unique HCV subtype profile among IDUs in the China–Myanmar border region have significant epidemiological and public health implications.

Systematic review: epidemiology and response to direct-acting antiviral therapy in genotype 6 chronic hepatitis C virus infection

BACKGROUND

Hepatitis C virus (HCV) genotype 6 (GT6) is predominantly encountered in Southeast Asia and data on GT6 response to direct-acting antiviral (DAA) therapy are relatively limited.

AIM

To review the epidemiology and virologic outcome of DAA regimens in HCV GT6 patients.

METHODS

Electronic literature search of PubMed, EMBASE, and The Cochrane Library databases were conducted.

RESULTS

Hepatitis C virus genotype 6 is the most genetically diverse, has a prevalence of 19.9%-95.6% in HCV infected patients in Southeast Asia and has been associated with a higher risk of HCC in those with cirrhosis. After an extensive literature review, a total of 20 studies were selected to assess study population and treatment outcomes (total of 938 GT6 patients were included); 12 were clinical trials and eight were observational studies. Sustained virologic response at week 12 (SVR 12) following glecaprevir/pibrentasvir (n = 4; 108 patients), ledipasvir/sofosbuvir (n = 8; 427 patients), sofosbuvir/velpatasvir with or without voxilaprevir (n = 5; 171 patients), sofosbuvir/daclatasvir (n = 3; 172 patients) and sofosbuvir with ribavirin (n = 3; 60 patients) was 98%-100%, 64%-100%, 100%, 88%-94% and 100%, respectively. Failure was mostly in those with cirrhosis and prior treatment experience. DAA therapy was well tolerated and with a serious adverse event rate of <5%.

CONCLUSIONS

Hepatitis C virus genotype 6 is genetically diverse and is highly prevalent in Asia. While SVR rates have been high, cirrhosis and prior treatment experience marginally compromise response to DAAs. Large scale and exclusive studies in HCV genotype 6 prevalent areas are needed, while the current evidence suggests that DAAs are highly effective and safe.

Safety and efficacy of sofosbuvir-based direct-acting antiviral regimens for hepatitis C virus genotype 6 in Southwest China: Real-world experience of a retrospective study

Optional treatments for patients with chronic hepatitis C virus (HCV) genotype (GT) 6 infection have not been extensively studied. This study aimed to evaluate the safety and efficacy of sofosbuvir (SOF)-based direct-acting antiviral agents (DAAs) for HCV GT6. We performed a retrospective study at the West China Hospital of Sichuan University in Southwest China from January 2016 to May 2017. Our study screened 130 treatment-naïve patients with chronic HCV GT6 and without liver cirrhosis. A total of 60 HCV GT6 patients were ultimately enrolled. All patients received SOF-based DAAs therapy, including SOF 400 mg plus daclatasvir (DCV) 60 mg daily or SOF 400 mg plus velpatasvir (VEL) 100 mg daily for 12 weeks. The sustained virological response 12 weeks after treatment (SVR12) was 100% (60/60) in treatment-naïve patients with HCV GT6, including 100% (37/37) of patients receiving SOF plus DCV therapy and 100% (23/23) of patients receiving SOF plus VEL therapy. Measurements of liver stiffness were significantly decreased in patients at week 12 (P = 0.014) and week 24 (P < 0.001) of DAAs treatment compared to baseline values. The serum biomarker aspartate aminotransferase-to-platelet ratio index (APRI) and fibrosis-4 score were also significantly reduced at week 12 and week 24 compared to before treatment (both P < 0.001). SOF-based therapy was well-tolerated, and no serious adverse events were reported. In conclusion, SOF plus DCV and SOF plus VEL were safe and achieved a high SVR12 rate for treatment-naïve patients with HCV GT6 without liver cirrhosis.

Strategy and Efficacy of Generic and Pan-genotypic Sofosbuvir/Velpatasvir in Chronic Hepatitis C Virus: A Myanmar Experience

BACKGROUND

In resource-constrained areas, generic direct-acting antivirals (DAAs) have considerably reduced the cost of hepatitis C virus (HCV) therapy while there remain significant costs related to the baseline and follow-up virologic assays.

AIM

The aim was to assess the efficacy and safety of HCV therapy in Myanmar with pan-genotypic generic DAA sofosbuvir/velpatasvir (SOF/VEL) and with and without the baseline genotype testing, while the duration of treatment and use of ribavirin (RBV) was dictated by cirrhosis and prior treatment failure.

METHODS

Between September 2016 and June 2017, data from the 359 participants who completed treatment with SOF/VEL (± RBV) for 12-24 weeks were analyzed. Two hundred one patients did not have the baseline HCV genotype tested.

RESULTS

Regimens included SOF/VEL for 12 weeks (n = 43), SOF/VEL/RBV for 12 weeks (n = 275), or SOF/VEL/RBV for 24 weeks (n = 41). The mean age was 52 years, 44% were men (n = 159), 41 (11.4%) had a history of previous DAA therapy, 7 (1.9%) had a history of hepatocellular carcinoma, and 55 (15.3%) had cirrhosis. Overall, the sustained viral response (SVR)12 rate was 98.6% (354/359) and with a good adverse event profile. SVR rates were similar to those with and without baseline genotype testing and also across all genotypes in those who had genotype tested.

CONCLUSIONS

In Myanmar, generic and pan-genotypic SOF/VEL ± RBV is a highly effective and safe treatment for HCV, regardless of the HCV genotype, and therefore, the requirement for the baseline genotype can be eliminated. Future strategies should include elimination of treatment and end of treatment HCV RNA testing to enhance treatment uptake and further reduce cost.

Findings from a large Asian chronic hepatitis C real-life study

There is a paucity of information on chronic hepatitis C (CHC) patients treated with direct antiviral agents (DAAs) in Asia. We invited Asia-Pacific physicians to collate databases of patients enrolled for CHC treatment, recording baseline clinical, virologic and biochemical characteristics, sustained virologic response at week 12 (SVR12) and virologic failure. SVR12 outcome was based on intention to treat (ITT). Multivariate analysis was used to assess independent risk factors for SVR12 using SPSS version 20. A total of 2171 patients from India (n = 977), Myanmar (n = 552), Pakistan (n = 406), Thailand (n = 139), Singapore (n = 72) and Malaysia (n = 25) were collected. At baseline, mean age was 49 years, 50.2% were males, and 41.8% had cirrhosis. Overall, SVR12 was 89.5% and by genotype (GT) based on ITT and treatment completion, respectively, was 91% and 92% for GT1, 100% and 100% for GT2, 91% and 97% for GT3, 64% and 95% for GT4, 87% and 87% for GT6 and 79% and 91% for GT untested. Patients with cirrhosis had SVR12 of 85% vs 93% for noncirrhosis (P < 0.001) (RR 2.1, 95% CI 1.4-3.1, P = 0.0002). Patients with GT1 and GT3 treated with sofosbuvir/ribavirin (SR) had 88% and 89% SVR12, respectively, but those GT6 treated with sofosbuvir/ledipasvir (SL) had only 77.6% SVR12. Multivariate analysis showed absence of cirrhosis was associated with higher SVR12 (OR 2.0, 95% CI 1.3-3.1, P = 0.002). In conclusion, patients with GT1 and GT3 with/without cirrhosis had surprisingly high efficacy using SR, suggesting that Asians may respond better to some DAAs. However, poor GT6 response to SL suggests this regimen is suboptimal for this genotype.

Systematic review and meta-analysis: real-world effectiveness of direct-acting antiviral therapies in chronic hepatitis C genotype 3 in Asia

BACKGROUND

Genotype 3 (GT3) is a common chronic hepatitis C (CHC) genotype in Asia. Direct-acting antiviral (DAA) regimens have high cure rates, but real-world results are limited for Asia.

AIM

To determine the real-world effectiveness of DAAs for patients with CHC GT3 in Asia.

METHODS

A systematic search was performed in PubMed (including MEDLINE), Embase, and selected international meeting abstract repositories. Eligible studies were postmarketing observational studies from Asia with the primary outcome of sustained virological response 12 weeks after completion of treatment (SVR12).

RESULTS

A total of 15 studies with 4230 patients yielded a pooled SVR12 of 92.7%. High heterogeneity (I2=93.2%, P<0.0001) was noted. In subgroup analyses, patients with cirrhosis had 10.9% lower SVR12 than non-cirrhotic patients (88.6% vs 98.9%; P<0.0001) and contributed 69.5% of the heterogeneity. Prior treatment failure did not reduce the pooled SVR12 (treatment-naïve: 94.6%, 95% CI 91.3% to 96.7% vs treatment-experienced: 94.0%, 95% CI 77.5% to 98.6%; P=0.89). Twenty-four weeks of sofosbuvir+ribavirin dual therapy was the most commonly used regimen which led to similar SVR12 (OR=1.1, P=0.73) but lower adverse event rate than 12 weeks of sofosbuvir+ribavirin+pegylated interferon triple therapy.

CONCLUSION

Sofosbuvir+ribavirin for 24 weeks is the most widely used and generally well-tolerated DAA therapy in Asia. However, its effectiveness is not optimal in GT3 patients with cirrhosis.

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

BACKGROUND

Direct-acting antiviral (DAA) regimens have shown high efficacy and tolerability for patients with HCV genotype 1/1b (GT1/1b) in clinical trials. However, robust real-world evidence of interferon (IFN)-free DAA treatment for HCV GT1-infected patients in Asia is still lacking.

AIM

To systematically review and meta-analyse the effectiveness and tolerability of IFN-free DAA therapy for HCV GT1 infection in Asia.

METHODS

We included studies that enrolled adult patients with HCV GT1 infection in routine clinical practice in Asia, using IFN-free DAA regimens, and reported sustained virological response (SVR) after 12/24 weeks end-of-treatment by 31 May 2017. The pooled SVR rates were computed with a random-effects model. Subgroup analysis and meta-regression as previously registered in PROSPERO were performed to determine how pre-planned variables might have affected the pooled estimates.

RESULTS

We included 41 studies from eight countries and regions, comprising of 8574 individuals. The pooled SVR rates for GT1 were 89.9% (95% CI 88.6-91.1, I²  = 55.1%) with daclatasvir/asunaprevir (DCV/ASV) and 98.1% (95% CI 97.0-99.0, I²  = 41.0%) with ledipasvir/sofosbuvir ± ribavirin (LDV/SOF ± RBV). Baseline cirrhosis but not prior treatment history and age, attenuated the effectiveness of both regimens. Baseline resistance associated substitutions (RASs) severely attenuated SVR of DCV/ASV (65.4% vs 94.3%, P < 0.001) and only minimally with LDV/SOF ± RBV (94.5% vs 99.2%, P = 0.003). Patients with renal dysfunction treated with DCV/ASV showed a higher SVR rate (93.9% vs 89.8%, P = 0.046). Patients with hepatocellular carcinoma (HCC) LDV/SOF ± RBV achieved a lower SVR than those without HCC (94.1% vs 98.7%, P = 0.001).

CONCLUSION

All oral DAA treatment of HCV GT1 resulted in high cure rates in Asian patients in routine clinical practice setting including elderly patients and those with end-stage renal disease.

Influence of IL28B and MxA gene polymorphisms on HCV clearance in Han Chinese population

The high rate of chronic hepatitis C (CHC) was one of the key issues of global public health concern. Interferon (IFN)-λ relevant genes were in the antiviral treatment pathway, not only influenced hepatitis C virus (HCV) spontaneous clearance, but also affected the IFN-mediated viral clearance. The aim of this study was to identify the association of interleukin 28B (IL28B), myxovirus resistance A (MxA) gene polymorphisms with HCV spontaneous clearance and therapeutic response in Chinese CHC patients. IL28B and MxA gene genotypes were detected among 231 CHC carriers, 428 subjects with HCV spontaneous clearance and 662 CHC patients with pegylated IFN-α and ribavirin (pegIFN-α/RBV) treatment. Patients with MxA rs2071430 TT genotype were more likely to develop HCV infection chronicity (additive model: odds ratio (OR) 1.22, 95% confidence interval (CI) 1.01-1.48, P = 0.042). IL28B rs1298075 variant genotypes (additive model: OR 0.58, 95% CI 0.34-0.98, P = 0.040) and MxA rs17000900 variant genotypes (additive model: OR 0.54, 95% CI 0.30-0.99, P = 0.048) were less likely to achieve a sustained virological response. The life table indicated that patients with IL28B rs1298075 AG genotype were slower to achieve a viral load 106 copies/ml (all P < 0.05). This study illustrated that the carriage of IL28B rs12980275 AA had a positive effect on treatment response to pegIFN-α/RBV among Chinese CHC patients.

Efficacy and safety of sofosbuvir-based therapies in patients with advanced liver disease in a real-life cohort

Background

The combination of sofosbuvir (SOF) with ribavirin (RBV) or daclatasvir (DCV) or simeprevir (SIM) for the treatment of patients infected by chronic hepatitis C (CHC) have led to significantly increased rates of sustained virological response (SVR). However, there is only limited data regarding factors associated with treatment failure in a “real-life” cohort.

Patients and methods

Consecutive treatment-naive and treatment-experienced patients F3–F4 were treated with SOF-based interferon-free therapy in our hospital from November 2013 to July 2015. The primary endpoint was the proportion of patients with sustained virological response 12 weeks after cessation of therapy (SVR12).

Results

A total of 167 treatment-naive and 207 treatment-experienced patients were treated and followed up for 2 years (n=383). Overall, 71% were men; among them, 54% had cirrhosis and the median age was 53 years. SVR12 was achieved by 82% of the patients receiving SOF+RBV, 92% receiving SOF+DCV, and 79% receiving SOF+SIM. Metavir F4 and albumin serum were found as independent risk factors associated with treatment failure in groups receiving SOF+RBV (p=0.008 and p=0.001), SOF+DCV (p=0.038 and p=0.043), and SOF+SIM±RBV (p=0.014 and p=0.017), respectively. The most common adverse events were fatigue, nausea, headache, and anemia. Three patients discontinued the treatment due to an adverse event.

Conclusion

These findings suggest that 12-week SOF-based regimen plus RBV or DCV or SIM is an efficacious and well-tolerated treatment in CHC patients with fibrosis stage F3–F4. Patients, who display risk factors for cirrhosis, should be referred to an experienced viral hepatitis center.

Open Label Study of 8 vs. 12 Weeks of Ledipasvir/Sofosbuvir in Genotype 6 Treatment Naïve or Experienced Patients

OBJECTIVES

Hepatitis C genotype 6 (HCV-GT6) is one of the most prevalent genotypes in Southeast Asia. Ledipasvir and sofosbuvir fixed-dose combination (LDV/SOF FDC) for 12 weeks has been shown to be effective for multiple HCV genotypes including treatment-naïve HCV-6. Our goal was to examine treatment outcomes in a diverse HCV-6 population.

METHODS

We prospectively enrolled 60 HCV-GT6 patients at four US centers. Treatment -naïve without cirrhosis patients received open-labeled LDV/SOF FDC orally once a day for 8 weeks; All cirrhotic and/or treatment-experienced patients received LDV/SOF FDC for 12 weeks. The primary outcome was sustained virological response 12 weeks after therapy (SVR12). Secondary outcomes were adverse events (AEs) and/or serious adverse events (SAEs). All patients gave written consent.

RESULTS

Overall mean age was 58±10 and 58% were male. All patients were Asian and foreign born. The 8-week group included 20 patients (33.3%) and the 12-week included 40 patients (66.7%). There were 2 (5%) patients with decompensation, 3 with liver cancer (7.5%), and 14 with prior treatment (35%) in the 12-week group. SVR12 was 95.0% for the 8-week group (19/20) and 95.0% for the 12-week group (38/40). AEs included fatigue (5%), insomnia (3.3%), headache (1.7%), and nausea (1.7%); however, all patients completed the intended treatment duration. There were two treatment-unrelated SAEs.

CONCLUSIONS

LDV/SOF FDC for 8 or 12 weeks was safe and effective for patients without cirrhosis or prior treatment failure as well as for patients with cirrhosis and/or prior treatment failure, respectively.

Sofosbuvir induced steven Johnson Syndrome in a patient with hepatitis C virus-related cirrhosis

Sofosbuvir is an imperative drug used in treatment regimens for hepatitis C virus (HCV). It is considered relatively safe with fewer adverse effects than other treatments. Here, we report a rare and potentially serious, dermatologic, adverse effect following the use of sofosbuvir. A 35‐year‐old man with genotype 3‐related HCV cirrhosis presented with decompensated ascites and jaundice following 7 weeks of therapy with peginterferon alpha‐2a and oral ribavirin. After peginterferon withdrawal and stabilization, oral sofosbuvir and ribavirin were started; 10 days later, he developed itching over the trunk and legs, followed by multiple papules and vesicles over an erythematous base. Over the next 15 days, the rash progressed with the formation of blisters and peeling skin. Simultaneously, the oral mucosa and lips developed crusting and painful erosions. Considering drug‐induced Steven John Syndrome (SJS), sofosbuvir and ribavirin were withdrawn and the patient was treated with topical emollients, steroids, and supportive care. The lesions improved over the next 4 weeks, with some residual hyperpigmentation. Rechallenge with sofosbuvir alone at one eighth the dose resulted in similar skin and mucosal lesions after 2 months; these lesions also improved after sofosbuvir withdrawal. The Algorithm of Drug Causality for Epidermal Necrolysis score was 7, which suggested sofosbuvir as the very probable drug resulting in SJS in our patient. Conclusion: The appearance of SJS following sofosbuvir use is an important and potentially fatal complication from a drug that serves as the backbone of several HCV treatment regimens. Treating physicians must use sofosbuvir with caution and consider withholding or discontinuing this drug in patients with such severe dermatologic manifestations. (Hepatology Communications 2018;2:16–20)

Direct antiviral agents (DAAs) - A new age in the treatment of hepatitis C virus infection

Hepatitis C virus (HCV) is a global health problem, because infection frequently leads to chronic hepatitis C eventually progressing to liver cirrhosis and liver cancer. Improved insights into the HCV replication cycle and the role of HCV non-structural proteins have recently enabled to identify drugs directly acting on specific HCV target structures. Agents from three drug classes have been developed and approved by the health authorities. Combinations of two or more drugs from different classes achieve high (>90%) HCV clearance rates and are well tolerated. This interferon-free DAA (direct antiviral agent) therapy has revolutionized antiviral therapy in hepatitis C so that successful hepatitis C treatment can be offered to virtually all patients irrespective of their co-morbidity. This review provides an overview over currently approved regimens and outlines their use in clinical practice. In addition potential short-comings of the current therapeutic options such as drug-drug interactions and selection of viral resistance are addressed. DAA combination therapy has the potential to obtain global control over hepatitis C. However, easy access to DAAs, availability of reliable HCV diagnostics, and affordable costs remain still important goals, which must be reached to globally eliminate hepatitis C.