Revisiting the stopping rule for hepatitis C genotype 1 patients treated with peginterferon plus ribavirin.

BACKGROUND: The current stopping rule for peginterferon/ribavirin therapy in hepatitis C virus genotype-1 (HCV-1) patients is based on an early virological response (EVR, defined as >2 log(10) viral reduction at treatment week 12). We aimed to explore rapid stopping rules at week 4.

METHODS: We randomly allocated 528 HCV-1 patients into training and validation sets (at a 1∶2 ratio). The interleukin-28B rs8099917 genotypes and on-treatment virological responses were evaluated to determine the negative predictive value (NPV) for achieving a sustained virological response (SVR, defined as undetectable HCV RNA 24 weeks after end-of-treatment). The study was approved by the ethics committees of the participating hospitals. All of the patients gave written informed consent before enrollment.

RESULTS: A poor week 4 response (W4R), defined as a HCV RNA reduction of <1 log(10) IU/mL at week 4 or a week 4 HCV RNA>10,000 IU/mL with interleukin-28B non-TT genotype, had the highest NPV (95%). In the complete sample, poor W4R could identify 43.4% (59/136) of the non-responders, with an NPV of 95% and a false negative rate of only 0.8% (3/396). The multivariate analysis revealed that a poor W4R was the most important negative predictor (odds ratio/95% confidence intervals: 49.01/13.70-175.37), followed by the lack of an EVR. In addition to HCV RNA<1 log(10) IU/mL reduction, using the criteria of HCV RNA>10,000 IU/mL/non-TT genotype helped identifying an additional one-third of non-SVR patients at W4.Using the strategy of sequential rapid stopping rule strategy could identify 53.7% (73/136) of the non-responders (43.4% at week 4 and an addition 11.3% at week 12), as compared to 40.4% for the classical week-12 early stopping rule.

CONCLUSIONS: Sequential rapid stopping rules using on-treatment virological responses and interleukin-28B genotype can rapidly identify additional peginterferon/ribavirin non-responders.