Real-life use of elbasvir/grazoprevir in adults and elderly patients: a prospective evaluation of comedications used in the PITER cohort

Background: In patients treated for HCV infection, potential drug-drug interactions (DDIs) can occur among direct-acting antiviral drugs (DAAs) and comedications used. The real-life effectiveness and safety of elbasvir/ grazoprevir (ELB/GZR) among co-medicated HCV patients was evaluated. Methods: We prospectively evaluated consecutive patients from 15 clinical centres participating in PITER who were treated with ELB/GZR and had been followed for at least 12 weeks after treatment. Data were prospectively collected on the use of comedications (including discontinuation, dose modification and addition of drugs) and potential DDIs with DAAs. Results: Of the 356 patients with at least 12-week post-treatment follow-up (median age 67, range 50-88 years), 338 (95%) achieved sustained virological response. Of these, 219 (60%) had at least one comorbidity (median 2, range 1-6); information on comedication was available for 212 of them. Of 190 comedications used, 15 (8%) drugs were modified during ELB/GZR therapy, specifically in 9 (4%) patients they were interrupted, in 2 (1%) of whom, the comedication was interrupted before the DAA therapy because of potential DDI (that is, patients treated with carbamazepine); in 12 (6%) patients the comedications were modified in terms of dosage. In 29 (14%) patients, the comedications required monitoring when used with ELB/GZR, as well as with all available DAAs. Of the 190 drugs, 27 (14%) used in 67% of patients were free of DDIs when used with ELB/GZR, whereas they required monitoring if used with other DAA regimens. Conclusions: The results of this prospective study support findings that ELB/GZR is effective and safe in most treated patients.