RESUMO
BACKGROUND & AIMS: There is currently no virological cure for chronic hepatitis B but successful nucleos(t)ide analogue (NA) therapy can suppress hepatitis B virus (HBV) DNA replication and, in some cases, result in HBsAg loss. Stopping NA therapy often leads to viral relapse and therefore life-long therapy is usually required. This study investigated the potential to discontinue tenofovir disoproxil fumarate (TDF) therapy in HBeAg-negative patients. METHODS: Non-cirrhotic HBeAg-negative patients who had received TDF for ≥4years, with suppressed HBV DNA for ≥3.5years, were randomly assigned to either stop (n=21) or continue (n=21) TDF monotherapy. Standard laboratory tests including HBV DNA viral load, HBsAg and alanine aminotransferase (ALT) measurements, and adverse event reporting were carried out during treatment and post-treatment follow-up for 144weeks. RESULTS: Of the patients who stopped TDF therapy, 62% (n=13) remained off-therapy to Week 144. Median HBsAg change in this group was -0.59log10IU/ml (range -4.49 to 0.02log10IU/ml) vs. 0.21log10IU/ml in patients who continued TDF therapy. Four patients (19%) achieved HBsAg loss. Patients stopping therapy had initial fluctuations in viral load and ALT; however, at Week 144, 43% (n=9) had either achieved HBsAg loss or had HBV DNA <2,000IU/ml. There were no unexpected safety issues identified with stopping TDF therapy. CONCLUSIONS: This controlled study demonstrated the potential for HBsAg loss and/or sustained virological response in non-cirrhotic HBeAg-negative patients stopping long-term TDF therapy. Lay summary: Nucleos(t)ide analogue (NA) is usually a life-long therapy for HBV patients. This randomised controlled study investigated the discontinuation of tenofovir disoproxil fumarate (TDF) therapy in HBeAg-negative patients. Of the patients who stopped TDF therapy, 62% remained off-therapy to Week 144, of which 43% of patients had achieved either HBsAg loss or HBV DNA <2,000IU/ml. This offers a potential for long-term HBV-suppressed patients without cirrhosis to stop NA therapy under strict surveillance. Clinical trial number: NCT01320943.