Cyclosporine shows advantage over tacrolimus

Hepatitis C always recurs after liver transplantation, often damaging the new organ and rendering patients ineligible for retransplantation. Patients commonly use interferon-ribavirin combination therapy to combat the hepatitis and an immunosuppressant to guard against transplant rejection.

The most commonly used anti-rejection medication is tacrolimus, brand name Prograf, marketed by Astellas Pharma, although cyclosporine (Sandimmun) produced by Novartis is also used. The latter drug has been shown to have anti-viral activity, leading researchers to speculate it might also inhibit hepatitis C virus (HCV).

Clinical studies at the University of Florida have shown that cyclosporine can reduce HCV replication by 20%, compared to no reduction with tacrolimus, when administered over a 48 hour period. Furthermore, the cyclosporine appeared to work through a different pathway compared to interferon. These results were confirmed in cell culture studies showing the antiviral effect of the drug.

In a retrospective study the researchers also examined the cases of 115 people infected with hepatitis C who had undergone liver transplantation and had received interferon-based therapy alongside their anti-rejection medications. After 48 weeks, 46% of the patients taking cyclosporine had achieved a sustained virological response, compared with just 27% of the patients taking tacrolimus.

Although the study suggests that cyclosporine may have a beneficial role as a primary immunosuppressant, it must be noted that more patients taking cyclosporine died, mostly due to infections and hepatitis complications. This result may be attributable to a longer follow-up period for that group. A prospective comparative trial between the drugs should further evaluate these observations.