Therapeutic drug monitoring of telaprevir in chronic hepatitis C patients receiving telaprevir-based triple therapy is useful for predicting virological response

Results: The rates of undetectable hepatitis Cvirus RNA at week 4 [rapid virological response (RVR)] and at 24 weeks after therapy [sustained virological response (SVR)] were 71.4% and 82.9%, respectively. Of the patients with RVR, 90% achieved SVR. The mean telaprevirCtrough levels at days 3, 7 and 14 of SVR patients (2.748, 2.733 and 2.999 mg/mL, respectively) were significantly higher than those of non-SVR patients (1.616, 1.788 and 2.314 mg/mL, respectively) (all P,0.05). Multiple logistic regression analysis of possible predictors of SVR extracted higher telaprevirCtrough at day 3 (OR 1.012 by 0.001 mg/mL, P,0.0001) and interleukin 28B (rs8099917) TT allele (OR 6.16 versus non-TT alleles, P,0.0001). Conclusions: Therapeutic drug monitoring of telaprevir in the early stage of treatment is useful in clinical practice for predicting the virological response of patients receiving telaprevir-based triple therapy.