Review article: treatment as prevention - targeting people who inject drugs as a pathway towards hepatitis C eradication

Spatiotemporal Phylodynamics of Hepatitis C Among People Who Inject Drugs in India

BACKGROUND AND AIMS

Implementing effective interventions for HCV requires a detailed understanding of local transmission dynamics and geospatial spread. Little is known about HCV phylodynamics, particularly among high-burden populations, such as people who inject drugs (PWID).

APPROACH AND RESULTS

We used 483 HCV sequences and detailed individual-level data from PWID across four Indian cities. Bayesian phylogeographic analyses were used to evaluate transmission hotspots and geospatial diffusion of the virus. Phylogenetic cluster analysis was performed to infer epidemiologic links and factors associated with clustering. A total of 492 HIV sequences were used to draw comparisons within the same population and, in the case of coinfections, evaluate molecular evidence for shared transmission pathways. Overall, 139/483 (28.8%) of HCV sequences clustered with a median cluster size of 3 individuals. Genetically linked participants with HCV were significantly younger and more likely to be infected with HCV subtype 3b as well as to live and inject close to one another. Phylogenetic evidence suggests likely ongoing HCV infection/reinfection with limited support for shared HIV/HCV transmission pathways. Phylogeographic analyses trace historic HCV spread back to Northeastern India and show diffusion patterns consistent with drug trafficking routes.

CONCLUSIONS

This study characterizes HCV phylodynamics among PWID in a low and middle-income country setting. Heterogeneity and recent genetic linkage of HCV across geographically disparate Indian states suggest that targeted interventions could help prevent reimportation of virus through drug trafficking routes.

Monitoring hepatitis C virus treatment rates in an Opioid Treatment Program: A longitudinal study

BACKGROUND

Direct-acting antivirals (DAAs) are recommended for the treatment of hepatitis C virus (HCV) infection in patients treated with methadone or buprenorphine.

AIM

To assess HCV treatment rates in an Opioid Treatment Program (OTP).

METHODS

This longitudinal study included 501 patients (81.4% men, median age: 45 years; interquartile range: 39-50 years) enrolled in an OTP between October 2015 and September 2017. Patients were followed until September 2019. Data on socio-demographics, substance use, HCV infection, human immunodeficiency virus (HIV) infection and laboratory parameters were collected at entry. We analyzed medical records to evaluate HCV treatment. Kaplan-Meier methods and Cox regression models were used to analyze the DAA treatment uptake and to identify treatment predictors.

RESULTS

Prevalence of HCV and HIV infection was 70% and 34%, respectively. Among anti-HCV-positive (n = 336) patients, 47.2%, 41.3%, and 31.9% used alcohol, cannabis, and cocaine, respectively. HCV-RNA tests were positive in 233 (69.3%) patients. Twentyeight patients (8.3%) cleared the infection, and 59/308 (19.1%) had received interferon-based treatment regimens before 2015. Among 249 patients eligible, 111 (44.6%) received DAAs. Treatment rates significantly increased over time from 7.8/100 person-years (p-y) (95%CI: 5.0-12.3) in 2015 to 18.9/100 p-y (95%CI: 11.7-30.3) in 2019. In a multivariate analysis, patients with HIV co-infection were twice as likely to receive DAAs (HR = 1.94, 95%CI: 1.21-3.12) than patients with HCV mono-infection. Current drug use was an independent risk factor for not receiving treatment against infection (HR = 0.48, 95%CI: 0.29-0.80).

CONCLUSION

HCV treatment is evolving in patients with HCV-HIV co-infection. Ongoing drug use while in an OTP might negatively impact the readiness to treat infection.

HCV point-of-care screening programme and treatment options for people who use drugs in a metropolitan area of Southern Italy

BACKGROUND AND AIMS

People who use drugs (PWUD) represent an active reservoir of HCV infection. The prevalence of chronic HCV infection in PWUD in Italy remains unknown because of the lack of systematic screening. Thanks to direct-acting antiviral agents (DAAs), hepatitis C can now be cured in most patients. Thus, the next challenge is to provide linkage-to-care for these patients.

METHODS

In this scenario, we conducted a screening programme in PWUD attending seven Addiction Centers in Southern Italy, as well as a treatment programme in the Liver Unit of the University Hospital of Salerno. We used the OraQuick HCV antibody test to screen the PWUD (from 1 April to 30 September 2018).

RESULTS

593 subjects were consecutively enrolled in the programme; 250 (41.8%) were HCV-Ab-positive. 143 (24.1%) were aware of their infection and had been HCV-RNA-tested: 83 were positive and 60 negative. The remaining 107 subjects (18.1%) had never previously been tested and were unaware of their infection. A total of 160 (26.9%) HCV RNA-positive patients were found and offered antiviral therapy with DAAs. The sustained virological response rate was 98.5% and no adverse events were recorded. Two patients voluntarily discontinued treatment. No reinfections have been recorded to date.

CONCLUSIONS

The prevalence of HCV-Ab positivity was high in the PWUDs enrolled in this study, and almost half the patients were unaware of being HCV-positive. The linkage-to-care provided was safe and effective, and no case of reinfection was recorded.

Research gaps in viral hepatitis

Introduction

The World Health Organization has aimed for global elimination of both hepatitis B virus (HBV) and hepatitis C virus (HCV) by 2030. Treatments available to cure HCV and control HBV, as well as vaccination to prevent HBV infection, have certainly allowed for such bold goals, yet the final steps to usher in elimination require further evidence.

Discussion

We broadly discuss the needs for three major public health approaches. First, an effective vaccine exists for HBV and mass‐vaccination campaigns have resulted in decreases in hepatitis B surface antigen seroprevalence and overall rates of liver‐related morality. Still, HBV vaccination coverage is poor in certain regions of the world, while the reasons for such low coverage require further study. A prophylactic vaccine is probably needed to eliminate HCV, but is not being readily developed. Second, identifying HBV/HCV infected individuals remains a priority to increase awareness of disease status, particularly for key populations. Research evaluating large‐scale implementation of novel, rapid and mobile point‐of‐care tests would be helpful to determine whether increased awareness is achievable in these settings. Third, antiviral therapy allows for strong HBV suppression and HCV cure, while its access depends on financial factors among many others. Although there is strong evidence to treat key populations and specific groups with progressed disease, as stated in current guidelines, the advantages of extending treatment eligibility to decrease onward spread of HBV/HCV infection and prevent further burden of disease are lacking “real world” evidence. Novel anti‐HBV treatments are being developed to target intrahepatocellular HBV replication, but are still in the early phases of clinical development. Each of the strategies mentioned above has specific implications for HIV infection.

Conclusions

There are certainly effective tools to combat the spread of viral hepatitis and treat infected individuals – yet how they are able to reach key populations, and the infrastructure required to do so, continue to represent the largest research gap when evaluating the progress towards elimination. Continuously adapted and informed research is required to establish the priorities in achieving elimination goals.

Clinical effectiveness of pharmacy-led versus conventionally delivered antiviral treatment for hepatitis C in patients receiving opioid substitution therapy: a study protocol for a pragmatic cluster randomised trial

INTRODUCTION

Hepatitis C virus (HCV) infection affects 0.7% of the general population, and up to 40% of people prescribed opioid substitution therapy (OST) in Scotland. In conventional care, less than 10% of OST users are tested for HCV and less than 25% of these initiate treatment. Community pharmacists see this group frequently to provide OST supervision. This study examines whether a pharmacist-led 'test & treat' pathway increases cure rates for HCV.

METHODS AND ANALYSIS

This protocol describes a cluster-randomised trial where 60 community pharmacies provide either conventional or pharmacy-led care. All pharmacies offer dried blood spot testing (DBST) for HCV. Participants have attended the pharmacy for OST for 3 months; are positive for HCV genotype 1 or 3; are not co-infected with HIV and/or hepatitis B; have no decompensated liver disease; are not pregnant. For conventional care, pharmacists refer HCV-positive participants to a local centre for assessment. In the pharmacy-led arm, pharmacists assess participants themselves in the pharmacy. Drug prescribing is by nurse prescribers (conventional arm) or pharmacist prescribers (pharmacy-led arm). Treatment in both arms is delivered as daily modified directly observed therapy in a pharmacy. Primary trial outcome is number of sustained virological responses at 12 weeks after treatment completion. Secondary trial outcomes are number of tests taken; treatment uptake; completion; adherence; re-infection. An economic evaluation will assess potential cost-effectiveness. Qualitative research interviews with clients and health professionals assess acceptability of a pharmacist-led pathway.

ETHICS AND DISSEMINATION

This protocol has been ethically approved by the East of Scotland Research Ethics Committee 2 (15/ES/0086) and complies with the Declaration of Helsinki and principles of Good Clinical Practice. Caldicott guardian approval was given on 16 December 2016 to allow NHS Tayside to pass information to the cluster community pharmacies about the HCV test status of patients that they are seeing to provide OST supervision. NHS R&D approvals have been obtained from each health board taking part in the study. Informed consent is obtained before study enrolment and only anonymised data are stored in a secured database, enabling an audit trail. Results will be submitted to international peer-reviewed journals and presented at international conferences.

TRIAL REGISTRATION NUMBER

NCT02706223; Pre-results.

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.

Value of Comprehensive HCV Treatment among Vulnerable, High-Risk Populations

OBJECTIVES

The objective of this study was to explore the trade-offs society and payers make when expanding treatment access to patients with chronic hepatitis C virus (HCV) infection in early stages of disease as well as to vulnerable, high-risk populations, such as people who inject drugs (PWID) and HIV-infected men who have sex with men (MSM-HIV).

METHODS

A discrete time Markov model simulated HCV progression and treatment over 20 years. Population cohorts were defined by behaviors that influence the risk of HCV exposure: PWID, MSM-HIV, an overlap cohort of individuals who are both PWID and MSM-HIV, and all other adults. Six different treatment scenarios were modeled, with varying degrees of access to treatment at different fibrosis stages and to different risk cohorts. Benefits were measured as quality-adjusted life-years and a $150,000/quality-adjusted life-year valuation was used to assess social benefits.

RESULTS

Compared with limiting treatment to METAVIR fibrosis stages F3 or F4 and excluding PWID, expanding treatment to patients in all fibrosis stages and including PWID reduces cumulative new infections by 55% over a 20-year horizon and reduces the prevalence of HCV by 93%. We find that treating all HCV-infected individuals is cost saving and net social benefits are over $500 billion greater compared with limiting treatment. Including PWID in treatment access saves 12,900 to 41,200 lives.

CONCLUSIONS

Increased access to treatment brings substantial value to society and over the long-term reduces costs for payers, as the benefits accrued from long-term reduction in prevalent and incident cases, mortality, and medical costs outweigh the cost of treatment.