Efficacy of tenofovir disoproxil fumarate in antiretroviral therapy-naive and -experienced patients coinfected with HIV-1 and hepatitis B virus.

BACKGROUND Coinfection with human immunodeficiency virus type 1 (HIV-1) increases the risk of hepatitis B virus (HBV)-associated progressive liver disease. Lamivudine has potent activity against both HIV-1 and HBV; however, lamivudine-resistance mutations in HBV frequently develop. METHODS Substudies of the safety and efficacy of tenofovir disoproxil fumarate (tenofovir DF) for patients coinfected with HIV and HBV were undertaken within 2 phase 3 randomized controlled trials involving antiretroviral therapy-experienced (study 907) and -naive (study 903) HIV-infected populations. Inclusion criteria were detection of hepatitis B surface antigen, an HBV DNA level >106 copies/mL at baseline, and HBV DNA specimens available at week 24 (study 907) and week 48 (study 903). RESULTS In study 907, the mean decrease in HBV DNA was 4.9 log(10), after 24 weeks, for 10 patients randomized to receive tenofovir DF, compared with a mean increase of 1.2 log(10) for 2 patients randomized to receive placebo (P=.041). The mean decrease in HBV DNA during tenofovir DF treatment was similar for patients with wild-type (5.3 log(10)) and lamivudine-resistant (4.6 log(10)) HBV strains. In study 903, the mean decrease in HBV DNA was 3.0 log(10), after 48 weeks, for 6 patients randomized to receive lamivudine, compared with 4.7 log(10) for 5 patients randomized to receive lamivudine and tenofovir DF (P=.055). Four patients developed tyrosine-methionine-aspartate-aspartate mutations, all in the lamivudine-only treatment arm. CONCLUSION Tenofovir DF has potent anti-HBV efficacy in antiretroviral therapy-experienced and -naive individuals coinfected with HIV and HBV.