[Efficacy of lamivudine re-treatment and relapse patterns after initial lamivudine treatment for chronic hepatitis B infection].

Background/aims: The post-treatment relapse patterns and efficacy of lamivudine re-treatment for relapsed patients have not been clarified. The aims of this study were to evaluate the relapse patterns after discontinuing therapy and the effects of lamivudine re-treatment for relapsed patients after HBeAg seroconversion.
Methods: Therapy was discontinued after HBeAg seroconversion in 121 patients. Sixty-six patients were relapsed and included in this study. The duration of lamivudine re-treatment therapy was from 6-35 (mean: 16) months. Post-retreatment monitoring continued for 1-40 (mean: 8.9) months.
Results: Among the relapsed 66 patients, 50 (75.8%) had HBeAg reappearance while 16 (24.2%) remained HBeAg negative and anti-HBe positive. The cumulative relapse rates at 3, 6, 12 and 24 months were 27%, 47%, 60% and 66%, respectively. Forty-two relapsers received lamivudine re-treatment. Among them, 33 were HBeAg positive and 9 were HBeAg negative and anti-HBe positive, Response was achieved in 31 of the 42 patients (73.8%). The cumulative response rates at 6, 9 and 12 months were 62%, 69% and 72%, respectively. Six patients (14.3%) developed viral breakthrough. All patients were HBeAg positive chronic hepatitis B. The duration of lamivudine re-treatment was the only predictable factor for response of lamivudine re-treatment. Therapy was discontinued after response in 21 patients. Eleven patients were relapsed, including 6 who were HBeAg positive and 5 who were HBeAg negative. Predictive factors for post-retreatment relapse were age and the duration of additional lamivudine therapy after response.
Conclusions: The response rate of lamivudine re-treatment was significantly higher than in initial lamivudine treatments. The breakthrough and relapse rates, however, were similar in both initial and retreated lamivudine therapy.