Purpose: Lamivudine (LAM) resistance is common on lamivudine monotherapy for chronic hepatitis B. This study examined the safety and efficacy of telbivudine (LDT) given with adefovir (ADV) versus ADV monotherapy in patients with chronic, lamivudine-resistant HBV infection.
Methods: An open-label, 96 week study with planned recruitment of 150 HBeAg-positive, lamivudine-experienced Asian patients with a confirmed YMDD resistance mutation, randomized 1:1 to receive ADV alone or with LDT. The study was terminated early due to difficulty in enrolling monotherapy patients. At termination, 42 patients had received study medication for 8-61 weeks. Due to incomplete enrolment, summary statistics only were prepared, without significance testing.
Results: A total of 42 patients underwent rescue therapy (switch to ADV or LDT + ADV; n = 21 per group). Median treatment duration was 48 weeks in both groups. HBV DNA changes from baseline were greater in the LDT + ADV arm at all time points (Week 48: -7.4 log10 vs. -4.9 log10 copies/ml), and serum DNA was undetectable (<300 copies/mL) at week 48 in 38.5% (5/13) on LDT + ADV versus 0% (0/9) on ADV monotherapy Two patients (9.6%) on ADV monotherapy experienced virologic breakthrough without evidence of ADV resistance, but none on LDT + ADV; and no confirmed ADV resistance was observed in any on-treatment sample. HBeAg loss occurred in three patients on LDT + ADV and one patient on ADV monotherapy through week 48. Safety profiles were similar between the arms.
Conclusion: LDT + ADV combination treatment showed better outcomes against lamivudine resistant HBV than ADV alone, with a similar safety profile.
Keywords: Adefovir; Hepatitis B; Lamivudine-resistant; Telbivudine.