Responses are durable for up to 5 years after completion of peginterferon alfa-2a treatment in hepatitis B e antigen-positive patients.

BackgroundIn the large randomised NEPTUNE study, peginterferon alfa-2a 180g/wk for 48weeks produced higher hepatitis B e antigen (HBeAg) seroconversion rates 24weeks post-treatment (36%) than a lower dose (90g/wk) and/or shorter duration (24weeks) (range 14%-26%). AimTo determine seroconversion rates 5years after completion of treatment in NEPTUNE. MethodsHBeAg-positive patients who completed 24weeks' follow-up in NEPTUNE (with peginterferon alfa-2a 90g/wkx24weeks [group 1]; 180g/wkx24weeks [2]; 90g/wkx48weeks [3] or 180g/wkx48weeks [4]) were followed up. ResultsThree hundred and eighty three of the 544 patients in the original study were enrolled in the long-term follow-up study. Many patients (196 overall; more in groups 1-3 than 4) received nucleos(t)ide analogues or immunomodulators during follow-up, and more patients had missing data at year 5 in groups 2 and 4 (48weeks, 50/112) than in groups 1 and 3 (24weeks, 23/103), which confounds the planned per-protocol analysis. HBeAg seroconversion rates in groups 1, 2, 3 and 4 at year 5 were 47.5%, 50.7%, 52.2% and 67.1%, respectively, (odds ratio for group 4 versus 1-3: 2.02; 95% CI 1.21, 3.38), using multiple imputation methods for missing measurements. ConclusionSeroconversion rates are durable for up to 5years after completion of peginterferon alfa-2a therapy and, consistent with NEPTUNE, the results suggest that the licensed regimen (180gx48weeks) is more efficacious for HBeAg-positive patients than a lower dose and/or shorter treatment duration.