HCV antiviral therapy in injection drug users: difficult to treat or easy to cure?

Unlabelled: Background and rationale of the study. Hepatitis C infection is very common among injection drug users(IDUs). In clinical practice there is reluctance to treat IDUs, because considered difficult-to-treat. Aim of this study was to evaluate the response to antiviral treatment in IDUs compared to non-IDUs.

Main Results: In this observational retrospective study, 204 non cirrhotic patients(112 IDUs, 92 non-IDUs) with chronic hepatitis C, treated with PEG-IFN and ribavirin in a tertiary centre for IDUs of Southern Italy from 2008 to 2011 were analyzed. Age, sex, genotype, steatosis, response to previous therapy, rapid(RVR), early(EVR), end-of-treatment(ETR), sustained(SVR) virological response were evaluated. IDUs were mainly young and males, with prevalence of genotype 3. A higher SVR rate in IDUs group compared to non-IDUs only in PerProtocol(PP) analysis (90% vs. 78,9% ;p = 0.04). On the contrary, in IntentionToTreat(ITT) analysis, no significant difference was relieved. A higher SVR rate at ITT analyses in naïve non-IDUs patients was found (76,13% vs. 90%, p = 0.021), but at PP analysis wasn't confirmed. Treatment was well tolerated; a higher dropout rate was reported in IDUs (24 patients) compared to non-IDUs (2 patients). In order to exclude the effect of viral genotypes on SVR a genotype matched statistical analysis was done and no difference was found.

Conclusions: IDUs naïve patients, due to young age and high prevalence of genotype 3, appear good candidates to dual antiviral therapy with high SVR rates. Dropout is the main non-response cause among these subjects, but through an optimal monitoring program with a multidisciplinary setting, their "difficult to treat" characteristics can be overcome.