With the exception of pyrexia the frequency of the majority of the reported adverse reactions was notably less in CHB patients treated with Pegasys monotherapy compared with HCV patients treated with Pegasys monotherapy (see Table 4) Adverse events were experienced by 88% of Pegasys-treated patients as compared with 53% of patients in the lamivudine comparator group, while 6% of the Pegasys-treated and 4% of the lamivudine-treated patients experienced serious adverse events during the studies.