Safety analysis of raltegravir/truvada regimen in HIV/HCV co-infected patients without switchback after HCV treatment

INTRODUCTION Due to drug-drug interactions of HIV- and HCV-specific antivirals when initiating an HCV-therapy, the antiretroviral therapy (ART) often has to be changed. The spectrum of applicable antiretrovirals is small, therefore many patients were switched to raltegravir/truvada (RAL/TVD) in our cohort. Due to the relatively low genetic barrier of RAL, this regimen may be endangered to fail, if the NRTI backbone is not fully active because of pre-existing NRTI resistance. We investigated the long-term follow-up and safety of RAL/TVD in co-infected patients after hepatitis C virus (HCV) therapy was stopped and the protective antiretroviral effect of interferon ended. MATERIALS AND METHODS Twenty patients initiated a direct-acting antiviral (DAA) containing HCV therapy (8x faldaprevir, 6x telaprevir, 2x daclatasvir and 4x simeprevir) between 11/2011 and 01/2013. Seventeen were switched to RAL/TVD, three patients were not treated before, but started with the regimen. Diagnosis of HIV infection was dated between 1985 and 2010. The HI-viral suppression was monitored retrospectively to date. RESULTS Thirteen of the twenty patients (65%) remained on RAL/TVD after finishing HCV treatment, for seven patients, no data about their ART continuation was available, after HCV therapy had stopped. All remaining thirteen patients showed an HI-viral load below detection limit up to date (for 15 to 22 months, median 20 months). Only for four patients, historic resistance data were available but none showed NRTI mutations. CONCLUSIONS Switch to RAL/TVD as HIV ART due to initiating HCV therapy was safe for the observed small cohort even in long-term follow-up without switchback or a second ART switch. However, resistance data for the cohort was little, showing no NRTI mutations, indicating a relatively safe setting. Since no further data is available, physicians should keep in mind ART history, historical therapy failure and HIV-resistance while switching ART to treat HCV in co-infected patients. Further investigation in larger cohorts is needed, especially thinking of upcoming interferon-free HCV regimen in heavily pre-treated co-infected patients.