Viral kinetics during rescue treatment with intravenous silibinin in a patient with chronic hepatitis C genotype 4– A case report

Introduction: About 50% of patients with hepatitis C genotype 1 and 4 achieve a sustained virological response (SVR) under a therapy with PEG-Interferon and Ribavirin. Recently released, more efficient regimens with protease inhibitors are not indicated in genotype 4 Hepatitis C. Intravenous Silibinin (ivSIL) has been shown to be effective as rescue treatment for nonresponders to the current standard of care. Silibinin is an extract that is derived from the seeds of the milkthistle and has been shown to be a potent agent against the hepatitis C virus. We present the case of a 28-year-old female patient with HCV genotype 4 who received ivSIL in addition to standard of care therapy (SOC: Peginterferon Alpha 2a and Ribavirin).

Patients and Methods: The HCV-Infection was diagnosed in 2000. The assumed route of transmission was i.v. drug abuse. At the time of admission to our department the patient was therapy naive. In June 2011 a therapy with PEG-IFN and Ribavirin was started. The baseline HCV load was 3,2 Mio IU/ml. After 14 weeks of SOC the viral load dropped to 560 000 IU/ml (log drop<1). As a nonresponder to SOC, our patient obtained 20mg/kg intravenous Silibinin (Legalon SIL, Madaus-Rottapharm, Cologne, Germany) over a period of three weeks. HCV-RNA was quantified daily by a Realtime HCV-KIT (Abott) during iv-SIL. The infusion regimen was followed by standard therapy.

Results: The treatment was well tolerated. The only side effect was a short period of diarrhea during infusion. The HCV-load decreased from 560 000 IU/ml to undetectable (detection limit=3 IU/ml) after 21 days of ivSIL. For a period of four weeks after Silibinin therapy the patients HCV-load remained below detection limit. In week 22 we observed a slight rise in the HCV-load to 40 IU/ml under continued standard of care therapy. Therefore a second course of ivSIL rescue treatment is being considered.

Conclusion: ivSIL was an effective and well tolerated rescue treatment for our patient, a nonresponder to the combination therapy with PEG-Interferon and Ribavirin. A second course of rescue treatment with ivSIL or a prolonged first treatment course may be necessary to achieve a complete response.