title: Weight-based high- and low-dose ribavirin in combination with peginterferon α-2b therapy for genotype 2 chronic hepatitis C: A randomized trial.
abstract: OBJECTIVE
  The optimal ribavirin dose in the treatment of patients infected with hepatitis C virus (HCV) genotype 2 remains to be elucidated. We aimed to seek the optimal ribavirin dose required for this genotype in a randomized trial.
  
  
  METHODS
  We compared the efficacy and tolerability of the 24-week peginterferon α-2b (1.5 µg/kg/week) therapy in combination with a weight-based higher dose (600-1000 mg) and lower dose (400-800 mg) of ribavirin for genotype 2 patients. Noninferior margin was set at 10%.
  
  
  RESULTS
  A total of 120 patients were randomized to a higher-dose or a lower-dose group. Sustained virological response (SVR) by intention-to-treat analysis was achieved in 47/58 (81.0%, 90% confidential interval [CI]: 72.6-89.5) patients in the higher-dose group and 41/60 (68.3%, 90% CI: 58.5-78.2) patients in the lower-dose group (difference, -12.7%; 90% CI, -25.7 to 0.3). Relapse rates were 10% and 21.6% in the higher-dose and the lower-dose groups, respectively. Multiple logistic regression analysis showed that ribavirin dose/kg body weight was the only significant predictor of SVR (≥9.5 mg/kg per day vs <9.5 mg/kg per day; odds ratio = 3.34; 95% CI, 1.41-7.92; P = 0.006). Twenty-one (36.2%) in the higher-dose group required ribavirin dose reduction because of anemia, whereas seven patients (11.7%) did in the lower-dose group (P < 0.01). Three of the higher-dose group and two of the lower-dose group required premature termination of therapy.
  
  
  CONCLUSIONS
  Weight-based lower-dose ribavirin regimen was not equivalent to the higher-dose counterpart in the treatment of HCV genotype 2. We discourage treating these patients with low-dose ribavirin regimens. The peginterferon therapy in combination with ribavirin at a weight-based higher dose (600-1000 mg) remains the standard-of-care treatment for this genotype.
authors.affiliation: Division of Gastroenterology, Department of Internal Medicine, Tokai University School of Medicine, Isehara             Division of Gastroenterology, Department of Internal Medicine, Tokai University Hachioji Hospital, Hachioji             Ikegami General Hospital             Division of Gastroenterology, Department of Internal Medicine, Tokai University Tokyo Hospital, Tokyo             Division of Gastroenterology, Department of Internal Medicine, Tokai University Oiso Hospital, Nakagun             Hadano Red Cross Hospital, Hadano             Japan Medical Alliance Ebina General Hospital, Ebina             Hiratsuka City Hospital, Hiratsuka             Tomei-Atsugi Hospital, Atsugi             Chigasaki Municipal Hospital, Chigasaki             Kanagawa Dental College, Yokosuka, Japan.
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