ABSTRACT
INTRODUCTION AND AIM: We assessed the characteristics of virological response to a combination treatment of ombitasvir, paritaprevir, and ritonavir in hepatitis C virus genotype 1-infected elderly Japanese patients. MATERIAL AND METHODS: This multicenter prospective study was conducted at six locations in Japan. Seventy patients with chronic hepatitis C virus genotype 1b infection were orally administered ombitasvir/paritaprevir/ritonavir once daily for 12 weeks. The primary endpoint was the proportion of elderly patients with sustained virological response (SVR) 12 weeks after the completion of treatment. Adverse events were also recorded to evaluate drug safety and tolerability during the trial period. SVR in elderly patients (age > 65; 94% [47 / 50]) was lower than that in younger patients (100% [20 / 20]). RESULTS: No significant differences in SVR 12 weeks after the completion of treatment were observed between the age groups (P = 0.153). Adverse events were observed in 16 patients (23.3%). Multivariate analysis confirmed that the change or discontinuation of concomitant drugs owing to drug interactions was independent of risk factors for adverse events associated with this drug combination (P = 0.015; odds ratio, 15.9; 95% confidence interval, 1.79 - 148). Ombitasvir/paritaprevir/ritonavir combination treatment was highly effective in elderly patients. CONCLUSION: Tolerability should be monitored in older patients for whom concomitant medications are discontinued or changed because of drug interactions.