Comparative safety study on severe anemia by simeprevir versus telaprevir-based triple therapy for chronic hepatitis C

Background and Aim: The addition of hepatitis C virus (HCV) NS3/4A protease inhibitors to the pegylated interferon (PEG-IFN) α and ribavirin combination regimen (triple therapy) has dramatically improved treatment outcome. Unfortunately, anemia remains a common adverse effect. This study was done to compare the development of severe anemia during simeprevir- or telaprevir-based triple therapy. Methods: This retrospective multicenter study consisted of 837 consecutive Japanese HCV genotype 1 patients treated in a real-world clinical setting, 811 of whom were enrolled (simeprevir 281, telaprevir 530). The inosine triphosphate pyrophosphatase (ITPA) genotype at rs1127354 was determined for all studied patients. Logistic regression was done after propensity score matching to assess the risk of development of severe anemia. Results: Propensity score matching of the entire study population yielded 266 matched pairs. Severe anemia (nadir hemoglobin <9.0g/dL) was developed during the treatment period by 81 (30.5%) and 144 (54.1%) patients treated with simeprevir and telaprevir, respectively. Treatment with simeprevir was independently associated with a lower risk of severe anemia (odds ratio 0.25, 95% confidence interval 0.16-0.38, P<0.0001). Moreover, ITPA genotype, age, hemoglobin level, and estimated glomerular filtration rate at baseline were also independent factors associated with the development of severe anemia. Conclusions: Patients treated with simeprevir-based triple therapy have a lower risk of the development of severe anemia than those treated with telaprevir. Moreover, ITPA genotype and age may be useful for individualizing treatment to reduce the risk of anemia-related adverse effects.