A genotype-specific baseline score predicts post-treatment response to peginterferon alfa-2A in hepatitis B e antigen-negative chronic hepatitis B

Background: Peginterferon alfa-2a induces durable responses in some hepatitis B e antigen-negative patients, but robust pretreatment predictors are not available to identify likely responders. In this study we aimed to develop genotype-specific baseline scoring systems to predict response. Methods: Data from 323 hepatitis B e antigen-negative peginterferon alfa-2a recipients from three studies were analyzed. Scoring systems were developed using generalized additive models and multiple logistic regression analysis. Response was defined as hepatitis B virus DNA <2000 IU/mL alone (virological response) or in combination with alanine aminotransferase normalization (combined response) 48 weeks post-treatment. Results: Points were assigned to genotype B/C patients for: age, alanine aminotransferase ratio, genotype B or C, and hepatitis B surface antigen level; and to genotype D patients for age, hepatitis B surface antigen level and hepatitis B virus DNA level. Higher total scores (range 0-5 for B/C; 0-3 for D) indicated a higher likelihood of response. Among genotype B/C patients with scores of 0-1, 2 and ≥3, respectively, virological response rates were 16.7%, 25.8% and 70.2%, and combined response rates were 12.5%, 21.0% and 57.4%. Among genotype D patients with scores of 0-1, 2 and 3, respectively, virological response rates were 10.1%, 28.0% and 50.0%, and combined response rates were 7.8%, 28.0% and 33.3%. Conclusion: Genotype-specific baseline scoring systems can identify hepatitis B e antigen-negative patients with low or high likelihood of achieving sustained responses to peginterferon alfa-2a.