High-dose interferon alpha-2b induction therapy in combination with ribavirin for Japanese patients infected with hepatitis C virus genotype 1b with a high baseline viral load

Background

Although pegylated interferon (IFN) is now used in many countries as a standard therapy for chronic hepatitis C, the efficacy and safety of combination therapy of high-dose interferon alpha-2b induction with ribavirin are not fully evaluated, especially in Japanese patients infected with hepatitis C virus (HCV) genotype 1b with a high viral load.

Methods

Patients (n = 83) received daily, high-dose induction therapy of interferon alpha-2b (6 million units [MU] once daily for 2 weeks), followed by 6 MU three times weekly for 22 weeks. Oral ribavirin (800 or 600 mg/day) was given daily for 24 weeks, and then the patients were followed up for 24 weeks.

Results

Of the 83 patients, 67 (81%) had a biochemical response (BR), and 37 (45%) achieved a sustained BR (SBR). Virologic response (VR; undetectable serum HCV RNA level by polymerase chain reaction [PCR]) was noted in 55 (66%) patients, and sustained VR (SVR) in 16 (19%) patients. Baseline viral load did not influence treatment outcome. There was no significant difference in treatment outcome among treatment-naÏve patients, relapsers, and nonresponders to previous IFN monotherapy. Multivariate analyses identified serum ribavirin concentrations at week 8 of therapy (odds ratio [OR], 23.7; 95% confidence interval [CI], 1.84–61.1; P = 0.015) and negativity for serum HCV RNA at week 8 (OR, 22.5; CI, 1.76–57.5; P = 0.017, respectively) as two significant and independent predictors of SVR.

Conclusions

The efficacy of 24-week combination therapy of high-dose IFN alpha-2b induction and ribavirin deserves attention in HCV genotype 1b patients with a high viral load, especially in nonresponders to previous IFN monotherapy and patients with a very high viral load.