Quantitative Analysis of Hepatic CCCDNA during Combination Therapy of Peginterferon ALFA 2B Plus Adefovir Dipivoxil in Patients with Chronic Hepatitis B: Interim Analysis of a single Center Pilot Study

Abstract

Background: Hepatitis B Virus cccDNA is the replicative intermediate in the nuclei of infected hepatocytes that is responsible for viral persistence during chronic HBV infection and antiviral therapy. The aims of this study were 1) to determine changes in intrahepatic cccDNA levels in paired biopsy samples from patients during therapy with Peginterferon alfa 2b and adefovir dipivoxil (primary endpoint) using a quantitative PCR assay (Werle, Gastroenterology, in press) and 2) to study the safety and efficacy of the combination therapy for 48 weeks. Methods: 17 of 26 patients completed the 48 week course of combination therapy as of March 2004. Baseline characteristics: 9 patients were HBeAg positive, 8 were negative for HBeAg, median serum HBV DNA 2×106 copies/ml (PCR, LLQ 200 copies/ml), median ALT 3.1 xULN, median total intrahepatic HBV DNA 262 copies/hepatocyte and median intrahepatic cccDNA 2.8 molecules/hepatocyte. Results: 2 patients seroconverted to HBs antibodies, 2 additional patients showed HBe seroconversion. In 10/17 patients (58%) serum HBV DNA had become undetectable (<200 copies/mL). 7/17 patients were still PCR-positive with a median serum HBV DNA at week 48 of 1×102 copies/ml (–4.3log10 copies/mL reduction from baseline). ALT normalized in 9/17 (52%), improved in 5/17 (30%), and slightly increased in 3/17 patients (18%). One patient missed week 48 biopsy, accounting for 16 paired biopsies. Median intrahepatic total HBV DNA at week 48 was 2.1 copies/hepatocyte (–2.1log). Intrahepatic cccDNA was undetectable in 9/16 (56%), and still positive in 7/16 biopsies including 3 patients with unaffected cccDNA levels and 4 patients with increased intrahepatic cccDNA (max. x48). Except for one patient, persistence of cccDNA was accompanied by elevated ALT level (max. 1.7 xULN) and/or detectable serum HBV DNA. 10/16 (63%) patients showed an improvement in the METAVIR score, either in inflammation and/or fibrosis. No unexpected adverse events were reported. Conclusion: In this on-going small study cohort, administration of Peginterferon alfa 2b once weekly and adefovir dipivoxil 10mg daily was safe and well tolerated. Intrahepatic cccDNA copy numbers are reduced to undetectability (<3 copies/10.000 cells) in the majority of patients.