DAAs efficacy impaired in persons who had ever injected drugs
Persons who had ever injected drugs (PWID), either on opiate agonist therapy (OAT) or not, do not respond to direct-acting antiviral agents (DAA) as well as those who had never used drugs, a new study has shown.
The study included 1,752 patients with hepatitis C virus (HCV) infections. Sustained viral response 12 weeks after treatment (SVR12) was compared between those who had never injected drugs (n=818; median age, 54 years; 62 percent male) and PWIDs with (n=199; median age, 48 years; 92 percent male) and without (n=735; median age, 50 years; 85 percent male) OAT.
In the intention-to-treat analysis, 93 percent (n=1,628) achieved SVR12. Stratifying according to drug use behaviours, SVR12 was found to be highest among those who had never injected drugs (95 percent; n=778). In PWIDs with vs without OAT use, the corresponding rates were 89 percent and 92 percent.
Fifty-three patients relapsed at the end of treatment response, 17 of whom had confirmed relapses via phylogenetic analysis. Reinfection was determined in three patients who turned out to be PWIDs who had achieved SVR 4 weeks after the end of therapy.
Multivariate analysis identified ongoing drug use (odds ratio [OR], 0.22, 95 percent CI, 0.11–0.42; p<0.001), coinfection with HIV (OR, 0.57, 0.34–0.96; p=0.036) and cirrhosis (OR, 0.46, 0.30–0.71; p<0.001) as factors significantly predictive of lower SVR12 rates.
“In conclusion, HCV cure rates with interferon-free DAA combinations are high among PWID with and without OAT. However, the overall efficacy of DAAs in active drug users is lower, mainly due to losses of follow-up,” said researchers, noting that strategies that aim to improve adherence among PWIDs are needed.