Background/Aims: There is no consensus on the management of patients with adefovir (ADV)-resistant hepatitis B virus (HBV) infection. The aim of this study was to investigate whether tenofovir disoproxil fumarate (TDF) combined with lamivudine (LMV) is effective and safe in patients with resistance to or non-response to ADV.
Methods: Six patients with HBV-related cirrhosis, viral breakthrough during LMV therapy and viral breakthrough or non-response during ADV therapy were treated daily with TDF plus LMV for at least 6 months. The HBV DNA level, alanine aminotransferase (ALT), the Child–Pugh score and serum creatinine were monitored. Genotypic LMV- or ADV-resistant mutations were measured in stored samples.
Results: In five of six patients, ADV-resistant mutations at rt181 or rt236 were detected during ADV therapy. At 6 months of starting TDF/LMV combination, HBV DNA levels became undetectable (detection limit, 400 copies/ml) in four of six patients. Within 12 months, HBV DNA levels became undetectable in all patients, and ALT levels were normalized in four of six patients. These responses persisted up to the end of the observation period (median duration 16.5 months, range 6–21 months). The Child–Pugh scores improved in two of three patients with hepatic decompensation. No significant changes in serum creatinine were observed.
Conclusion: Our data demonstrated that TDF plus LMV safely and markedly suppressed HBV replication in patients with resistance to or non-response to ADV. This study suggests that this combination may be a promising rescue therapy for these patients, particularly those with liver cirrhosis or pre-existing LMV resistance.