Switching from Tenofovir and Nucleoside Analogue Therapy to Tenofovir Monotherapy in Virologically Suppressed Chronic Hepatitis B Patients with Antiviral Resistance.

It is unclear whether chronic hepatitis B (CHB) patients with antiviral resistance, who achieve a complete virologic response (CVR) with tenofovir disoproxil fumarate (TDF) and nucleoside analogue (NUC) combination therapy, maintain CVR if switched to TDF monotherapy. We investigated the persistence of CVR after cessation of NUC in virologically suppressed antiviral resistant CHB patients using TDF+NUC combination therapy. This study recruited 76 antiviral-resistant CHB patients showing CVR on TDF+entecavir (ETV) (n=52), TDF+lamivudine (LAM; n=14), and TDF+telbivudine (LdT; n=10) combination therapy, who were switched to TDF monotherapy as step-down therapy. At baseline, 47 patients were male and the median age was 53.0 years (range: 30-78 years); 72.3% cases were hepatitis B e antigen-positive (HBeAg+) and 23.7% were of liver cirrhosis. The median duration of TDF+NUC combination therapy was 20.8 months (range: 3-46 months). At a median follow-up of 24.7 months (range: 12-48 months) after switching to TDF monotherapy, all 76 patients maintained CVR, regardless of the duration of combination therapy and the type of prior NUC and antiviral resistance. Renal dysfunction was not observed during the treatment period. The step-down strategy of switching from TDF+NUC combination therapy to TDF monotherapy in virologically suppressed CHB patients with antiviral resistance should be considered.