Direct-acting antiviral treatment is highly effective at curing hepatitis C in people who inject drugs and in people receiving opioid substitution therapy (OST), a systematic review and meta-analysis of 38 studies published in The Lancet Gastroenterology and Hepatology shows. Experts from Australia’s leading hepatitis C research centre say that the findings of the review demonstrate that policies that deny hepatitis C treatment for people who use drugs are unacceptable.
The findings were published to coincide with the 7th International Symposium on Hepatitis Care in Substance Users, which took place last week in Portugal.
Despite a recommendation from the World Health Organization that people who use drugs should receive direct-acting antiviral treatment for hepatitis C, some countries do not provide treatment to active drug users and physicians often cite concern about adherence as a reason to deny treatment to active drug users.
But elimination of hepatitis C in people who inject drugs is unlikely to be achieved unless the number of people with hepatitis C who share injecting equipment can be reduced. This can only be achieved by a combination of provision of sterile needles and injecting equipment to reduce sharing, OST to reduce injecting and direct-acting antiviral treatment to reduce the number of people who are able to transmit hepatitis C.
To investigate whether people who inject drugs have poorer responses to direct-acting antiviral treatment, researchers from the Kirby Institute searched for all studies which reported the outcomes of direct-acting antiviral treatment in cohorts that included current or recent drug users (within the previous 12 months), or people receiving OST. The review included clinical trials and observational studies.
The review identified 38 studies with 3634 participants including five randomised clinical trials (634 participants) and five analyses of clinical trials conducted after the trial was completed to investigate responses in people who used drugs (517 participants).
Definitions of drug use or recent drug use in studies varied; 19 studies reported on current drug users (classified as current if they were using drugs at the beginning of the study or during the study) and 19 on recent drug users (anywhere from the previous month to 12 months prior to starting treatment). More than half of the studies (25) were carried out in people receiving OST. Participants might be using drugs at the same time as receiving OST.
Pooling the findings from studies, the meta-analysis showed a sustained virologic response rate of 87.7% in recent drug users (1408 participants, 95% CI 84.2-91.3%) and a sustained virologic response rate of 90.7% in OST recipients (2987 participants, 95% CI 88.5-93%). Treatment completion rates were high (97.5% in both recent drug users and OST recipients).
When the analysis was confined to people with recent injecting drug use, rather than all drug use, the sustained virologic response rate was 87.4% (treatment completion rate was 96.9%).
Cure rates were higher in clinical trials than in observational studies (93.9% vs 88.8%) and participants in clinical trials were less likely to be lost to follow-up. The researchers say that the lower rate of loss-to-follow-up in clinical trials is probably a consequence of more frequent clinic visits and more active follow-up of study participants.
"People should not be denied life-saving treatments, simply because of their recent drug use," said Associate Professor Jason Grebely from the Kirby Institute at the University of New South Wales.
"Policies that deny hepatitis C treatment for people who use or inject drugs are unacceptable; they are driven by discrimination as opposed to evidence. I hope our research will encourage countries to overturn these policies and allow treatment to all people living with hepatitis C, regardless of current or previous drug use. In fact, given high prevalence rates, people who inject drugs really should be prioritised for treatment." Associate Professor Grebely is also President of the International Network of Hepatitis in Substance Users (INHSU).
"The World Health Organisation has set a target to eliminate hepatitis C by 2030," said Associate Professor Grebely. "Our data provides robust evidence to inform global clinical guidelines, and we hope it will improve public health policy for hepatitis C treatment for people who use drugs internationally. This will bring us closer to the ambitious goal of global elimination."