Efficacy of elbasvir/grazoprevir therapy in HCV genotype-1 with or without HIV infection: role of HCV core antigen monitoring and improvement of liver stiffness and steatosis.

Background: The combination of elbasvir and grazoprevir (EBR/GZR) has been approved for treating HCV infection. This study aimed to evaluate the efficacy of EBR/GZR in terms of sustained virological response (SVR) and improvement of liver fibrosis in Thai patients with HCV genotype-1 (GT1). The utility of serum HCV core antigen (HCVcAg) as an alternative to HCV RNA in assessing SVR was also investigated.

Methods: A total of 101 HCV GT1-infected patients (65 monoinfection and 36 HIV coinfection) who received EBR/GZR for 12-16 weeks were included. Liver stiffness (LS) and controlled attenuation parameter (CAP) were measured by transient elastography. Serum HCVcAg was measured in parallel with HCV RNA.

Results: The overall SVR12 and SVR24 rates in the cohort were 98.0% and 95.0%, respectively. SVR24 rates were consistently high (90.0% to 100%) across all subgroups of patients. A significant LS decline ³30% was observed more frequently in cirrhotic than non-cirrhotic individuals who achieved SVR (63.3% versus 30.3%; P=0.003). The magnitude of LS decline following HCV eradication was comparable between HCV monoinfection and HCV-HIV coinfection. The reduction of CAP was also observed in responders who had significant steatosis at baseline. Compared with HCV RNA, HCVcAg testing displayed high sensitivity (100%) and specificity (99.0-100%) in determining SVR12 and SVR24.

Conclusions: This study confirms that EBR/GZR is effective for HCV GT1-infected Thai patients with or without HIV infection. HCV eradication is associated with LS and CAP improvement regardless of HIV status. HCVcAg testing could be a potential replacement for HCV RNA for assessing SVR in resource-limited settings.