Efficacy of tenofovir disoproxil fumarate/emtricitabine compared with emtricitabine alone in antiretroviral-naive HIV-HBV coinfection in Thailand

Background: Therapy for chronic hepatitis B with tenofovir disoproxil fumarate (TDF) and lamivudine (3TC) or emtricitabine (FTC) is currently recommended for HIV-HBV coinfection. However, there is limited randomized data on the efficacy of combined therapy with TDF and FTC, especially in antiretroviral (ARV)-naive patients. Methods: This was a prospective randomized clinical trial comparing the efficacy of HBV monotherapy with FTC versus TDF/FTC combination therapy in ARV-naive HIV-HBV coinfection. HIV-HBV-coinfected patients initiating ARV were randomized to either FTC/zidovudine/efavirenz (EFV; n=6) or TDF/FTC/EFV (n=10). The primary end point was the time-weighted area under the curve (TWAUC) of HBV DNA at 48 weeks. Results: The median baseline CD4(+) T-cell count was 64 cells/mu l (interquartile range [IQR] 36-172), plasma HIV type-1 RNA was 4.90 log(10) copies/ml (IQR 4.58-5.44) and plasma HBV DNA was 8.76 log(10), copies/ml (IQR 8.45-8.82). A total of 11/16 (69%) patients were hepatitis B e antigen (HBeAg)-positive. The median TWAUC decrease in HBV DNA was -5.32 log(10) copies/ml in the TDF/FTC group compared with -3.25 log(10) copies/ml in the FTC group (P=0.03). At week 48, 90% of the TDF/FTC group and 33% of the FTC group had plasma HBV DNA<170 copies/ml (P=0.036, intention-to-treat analysis). HBeAg loss was observed in 4/11 (36%) HBeAg-positive patients. Hepatic flares were observed in 3/16 (19%) of patients. Conclusions: TDF/FTC combination therapy resulted in a significantly greater decrease in HBV DNA than FTC monotherapy, with a greater proportion of patients with undetectable HBV DNA at week 48. Our study supports the current recommendation of ARV containing TDF/FTC as the treatment of choice for patients with HIV-HBV coinfection.