Virological responses to tenofovir-alafenamide-containing antiretroviral therapy in people living with HIV co-infected with lamivudine-resistant or lamivudine-susceptible hepatitis B virus

Abstract

Background: Data on the effectiveness of tenofovir alafenamide (TAF) against lamivudine-resistant (LAM-R) hepatitis B virus (HBV) among patients co-infected with human immunodeficiency virus (HIV) and HBV are limited.

Methods: Between April and December 2018, HIV-positive patients co-infected with LAM-R or lamivudine-susceptible (LAM-S) HBV who switched from tenofovir-disoproxil-fumarate-containing antiretroviral therapy (ART) to TAF-containing ART were followed for 96 weeks. Plasma HBV and HIV loads, HBV serological markers, and liver function before and after the switch were analysed.

Results: In total, 182 patients co-infected with HIV and HBV were included in this study: 45 with LAM-R HBV and 137 with LAM-S HBV. At baseline, 28.9% and 7.4% of patients in the LAM-R and LAM-S groups, respectively, tested positive for hepatitis B virus envelope antigen (HBeAg) (P<0.001), and the respective percentages of patients who had achieved plasma HBV DNA <20 IU/mL were 95.5% and 97.1%. At weeks 48 and 96, 100% and 94.9% of patients in the LAM-R group, respectively, and 97.1% and 95.6% of patients in the LAM-S group, respectively, maintained plasma HBV DNA <20 IU/mL. Lamivudine resistance of HBV and baseline hepatitis B virus surface antigen (HBsAg) level were associated with HBsAg decrement at week 96 at a degree of 0.25 log₁₀ IU/mL [95% confidence interval (CI) 0.059-0.246] and 0.22 log₁₀ IU/mL (per 1-log₁₀IU/mL increase, 95% CI 0.018-0.101), respectively. At week 96, 2.2% (4/182) of patients had HBsAg loss; no patients in the LAM-R group and 25.0% (2/8) of patients in the LAM-S group had HBeAg seroconversion.

Conclusions: Switching to TAF-containing regimens maintained high rates of HBV viral suppression in patients co-infected with either LAM-R or LAM-S HBV. The decrease in HBsAg was minimal, and HBsAg seroconversion occurred infrequently.

Keywords: Antiviral resistance; Hepatitis B virus envelope antigen; Hepatitis B virus surface antigen; Nucleos(t)ide analogue; Seroconversion; Tenofovir alafenamide.