Hepatitis C virus treatment for prevention among people who inject drugs: Modeling treatment scale-up in the age of direct-acting antivirals.

Natasha K Martin,Graham R Foster,Jason Grebely,Matthew Hickman,David J Goldberg,Gregory J Dore,Sharon J Hutchinson,Peter Vickerman,Margaret Hellard,Viviane D Lima,John F Dillon

doi:10.1002/hep.26431

Abstract

Substantial reductions in hepatitis C virus (HCV) prevalence among people who inject drugs (PWID) cannot be achieved by harm reduction interventions such as needle exchange and opiate substitution therapy (OST) alone. Current HCV treatment is arduous and uptake is low, but new highly effective and tolerable interferon-free direct-acting antiviral (DAA) treatments could facilitate increased uptake. We projected the potential impact of DAA treatments on PWID HCV prevalence in three settings. A dynamic HCV transmission model was parameterized to three chronic HCV prevalence settings: Edinburgh, UK (25%); Melbourne, Australia (50%); and Vancouver, Canada (65%). Using realistic scenarios of future DAAs (90% sustained viral response, 12 weeks duration, available 2015), we projected the treatment rates required to reduce chronic HCV prevalence by half or three-quarters within 15 years. Current HCV treatment rates may have a minimal impact on prevalence in Melbourne and Vancouver (<2% relative reductions) but could reduce prevalence by 26% in 15 years in Edinburgh. Prevalence could halve within 15 years with treatment scale-up to 15, 40, or 76 per 1,000 PWID annually in Edinburgh, Melbourne, or Vancouver, respectively (2-, 13-, and 15-fold increases, respectively). Scale-up to 22, 54, or 98 per 1,000 PWID annually could reduce prevalence by three-quarters within 15 years. Less impact occurs with delayed scale-up, higher baseline prevalence, or shorter average injecting duration. Results are insensitive to risk heterogeneity or restricting treatment to PWID on OST. At existing HCV drug costs, halving chronic prevalence would require annual treatment budgets of US $3.2 million in Edinburgh and approximately $50 million in Melbourne and Vancouver. Conclusion: Interferon-free DAAs could enable increased HCV treatment uptake among PWID, which could have a major preventative impact. However, treatment costs may limit scale-up, and should be addressed. (Hepatology 2013;58:1598–1609)

Highlights

Substantial reductions in hepatitis C virus (HCV) prevalence among people who inject drugs (PWID) cannot be achieved by harm reduction interventions such as needle exchange and opiate substitution therapy (OST) alone
Reducing prevalence by 3=4 would require a scale-up of three-fold in Edinburgh, 18-fold in Melbourne, and 20-fold in Vancouver. This would result in HCV chronic prevalences of
The cost of future IFN-free direct-acting antiviral (DAA) regimens is unknown, but if they cost $50,000 ($25,000-$75,000), the scaled-up treatment rates necessary to halve prevalence within 15 years (15, 40, and 76 per 1,000 PWID annually in Edinburgh, Melbourne, and Vancouver, respectively) would require an annual HCV treatment budget for PWID of $3.2 million ($1.6-$4.7 million) in Edinburgh, $50.0 million ($25-$75 million) in Melbourne, and $51.3 million ($25.7-$77.0 million) in Vancouver. This modeling study explored the feasibility of HCV treatment as prevention in the era of IFN-free DAA-based HCV therapy

Summary

Introduction

Substantial reductions in hepatitis C virus (HCV) prevalence among people who inject drugs (PWID) cannot be achieved by harm reduction interventions such as needle exchange and opiate substitution therapy (OST) alone. Mathematical modeling studies have suggested HCV treatment for PWID could be an effective[12,13,14,15,16] and cost-effective[17] intervention to prevent HCV transmission These studies only considered treatment with pegylated interferon (PEG-IFN) and ribavirin (RBV). Preliminary data from IFNfree direct-acting antiviral (DAA) therapy phase 2 trials indicates that in the near future, regimens will be available with markedly reduced toxicity, high efficacy (>90% cure), improved dosing schedules (once or twice-daily), and shortened treatment duration (6-24 weeks).[20,21,22] Such advances indicate that a HCV treatment as prevention strategy among PWID may be feasible in the very near future

Objectives

Methods

Results

Conclusion