Theme: Clinical Research Year: 2018
There are concerns around poorer adherence and response to direct-acting antiviral (DAA)
therapy for HCV among people using drugs. This systematic review assessed DAA
treatment outcomes among people with recent drug use and those receiving opioid
substitution therapy (OST).
Bibliographic databases were searched for studies assessing DAA treatment completion and
sustained virologic response (SVR) among people with recent drug use (injecting or noninjecting) and/or those receiving OST. Meta-analysis was used to cumulate estimates and
meta-regression to explore heterogeneity.
Thirty-eight eligible studies were included (n=3,632 participants), including sub-population
data of people receiving OST (36 studies, n=2,985), people with recent drug use (22 studies,
n=1,550) and people with recent injecting drug use (14 studies, n=937). Recent drug use
definition varied across studies (drug use in the past six months and during DAA therapy
most commonly used). In OST sub-population, treatment completion was 97.6%
(95%CI:96.7-98.4) and SVR was 91.1% (95%CI:88.9-93.3). Among people with recent drug
use, treatment completion was 96.9% (95%CI:95.8-97.9) and SVR was 88.4% (95%CI:85.0-
91.8). Among people with recent injecting drug use, treatment completion was 96.2%
(95%CI:94.9-97.6) and SVR was 85.9% (95%CI:80.7-91.1). In modified intent-to-treat
analysis (excluding participants lost-to-follow-up post-treatment without SVR assessment),
SVR was 94.7% (95%CI:93.2-96.2) in people receiving OST, 92.8% (95%CI:90.6, 95.1) in
people with recent drug use, and 91.4% (95%CI:88.4-94.5) in people with recent injecting
drug use. Compared to observational studies, clinical trials reported higher treatment
completion (98.2%, 95%CI:97.4-99.0 vs. 96.8%, 95%CI:95.7-97.9), and SVR (94.3%,
95%CI:92.7-95.9 vs. 88.9%, 95%CI:85.9-92.0). Differences were significant in adjusted
meta-regression analysis (treatment completion OR: 1.7, 95%CI:1.1-2.7, P=0.028; SVR OR:
2.3, 95%CI:1.4-3.9, P=0.002). Lost-to-follow-up was higher in observational studies (4.7%,
95%CI:3.0-6.5), than clinical trials (2.1%, 95%CI:0.8-3.3).
DAA-based treatment outcomes are highly favourable among people receiving OST. Lower
treatment responses in people with recent drug use, particularly those with recent injecting,
requires further exploration.
Disclosure of interest Statement:
The Kirby Institute is funded by the Australian Government Department of Health and
Ageing. The views expressed in this publication do not necessarily represent the position of
the Australian Government. BH supported by a National Health and Medical Research
Council Early Career Fellowship. JG is supported by a National Health and Medical
Research Council Career Development Fellowship. GD is supported by a National Health
and Medical Research Council Practitioner Research Fellowship. JG is a consultant/advisor
and has received research grants from Abbvie, Cepheid, Gilead Sciences and Merck/MSD.
GD is a consultant/advisor and has received research grants from Abbvie, Bristol Myers
Squibb, Gilead, Merck, Janssen and Roche.