Safety and anti-HCV effect of prolonged intravenous silibinin in HCV genotype 1 subjects in the immediate liver transplant period

Background & Aims Reinfection of the graft is the rule in patients with HCV cirrhosis undergoing liver transplantation, and HCV-RNA reaches pre-transplantation levels within the first month. Short-term intravenous silibinin monotherapy is safe and shows a potent in vivo anti-HCV effect. We aimed at evaluating the safety and antiviral effect of prolonged intravenous silibinin, started immediately before liver transplantation. Methods Single centre, prospective, pilot study, to assess the safety and effect on HCV-RNA kinetics during at least 21days of intravenous silibinin monotherapy (20mg/kg/day) in 9 consecutive HCV genotype 1 subjects, in comparison to a control, non-treated group of 7 consecutive prior transplanted subjects under the same immunosuppressive regimen (basiliximab, steroids, delayed tacrolimus, micophenolate). Results Intravenous silibinin led to significant, maintained and progressive HCV-RNA decreases (mean HCV-RNA drop at week 3, −4.1±1.3log 10 IU/ml), and lack of viral breakthrough during administration. Four patients (44%) reached negative HCV-RNA, maintained during silibinin treatment, vs. none in the control group, but HCV-RNA relapsed in all of them after a median of 21days (16–28), following silibinin withdrawal. Partial responders to silibinin showed marked decreases in HCV-RNA when compared to controls, but lower than complete responders. There were no clinical adverse effects, and silibinin led to asymptomatic transient hyperbilirubinemia (week 2, 4.2±2.2 vs. 2.5±3.6mg/dl; p =0.02). Conclusions Prolonged intravenous silibinin monotherapy was safe in the immediate liver transplantation period, leading to a potent and time dependent antiviral effect and lack of HCV-RNA breakthrough during administration. However, HCV-RNA rebounded after withdrawal, and silibinin monotherapy did not avoid reinfection of the graft.