Long-term efficacy and safety of switching from lamivudine+adefovir to tenofovir disoproxil fumarate in virologically suppressed patients

Abstract

Background and aim: Tenofovir disoproxil fumarate (TDF) is recommended as first-line monotherapy for nucleos(t)ide (NA)-naïve chronic hepatitis B (CHB) patients and as a second-line rescue therapy for NA-experienced patients with a previous treatment failure. However, data regarding the efficacy of TDF monotherapy in patients with lamivudine resistance (LAM-R) successfully treated with LAM+adefovir (ADV) are limited. Herein, the efficacy and safety of switching from LAM+ADV to TDF monotherapy in clinical practice have been evaluated.

Methods: Sixty LAM-R HBeAg-negative CHB patients treated with ADV add-on therapy and stable viral suppression, were switched to TDF monotherapy and prospectively evaluated for virological response, liver and renal function, and bone mineral density.

Results: During a median period of 57 months of TDF monotherapy, all patients maintained a virological response, four of whom cleared HBsAg (6.6%) and discontinued treatment. Monitoring of renal function showed no case of the Fanconi syndrome, no significant alterations of median serum creatinine, eGFR and phosphate levels, although a reduction of TDF dosage was required in five patients (8.3%). Despite the stable virological suppression, five cirrhotic patients and one CHB patient developed hepatocellular carcinoma.

Conclusions: Our results demonstrate the efficacy of switching to TDF monotherapy in virologically suppressed CHB patients receiving long-term LAM+ADV therapy, with a low rate of adverse events.

Keywords: Antiviral therapy; Chronic hepatitis B; Nucleos(t)ide analogues; Tenofovir.