Kinetics and Predictors of Hepatitis B Surface Antigen Loss After Commencing Hepatitis B Virus (HBV)-Active Antiretroviral Therapy in the Setting of HIV and Chronic HBV Coinfection.

Abstract

An effective therapeutic strategy for hepatis B virus (HBV) cure remains an urgent unmet need. We aimed to define the incidence, kinetics, and predictors of hepatitis B surface antigen (HBsAg) loss in people with HIV and HBV (PWH-HBV) following HBV-active antiretroviral therapy (ART) in PWH-HBV in Asia. 97 PWH-HBV commencing HBV-active ART were recruited prospectively in Thailand (n = 94) and Malaysia (n = 3), then followed for 24 months. Time to HBV serology change was calculated. Univariate associations between baseline characteristics and HBsAg loss were examined using the Mann-Whitney or chi-square tests. Multivariable analysis was undertaken using Cox regression. Twenty-one individuals (22%) lost HBsAg during follow-up (11.7 per 100 person-years), 14 of whom gained anti-HBs. Twenty-two of 61 (36.1%) individuals who were hepatitis B "e" antigen (HBeAg) positive at baseline lost HBeAg over the study, 15 of whom gained anti-HBe. Most individuals lost HBsAg and HBeAg by the month 12 study visit (81% and 63.6%, respectively), with median times of 5.8 and 12.0 months to HBsAg and HBeAg loss, respectively. Univariate analysis showed baseline characteristics associated with HBsAg loss were higher alanine aminotransferase (ALT; P = .005), tenofovir alafenamide (TAF)-containing ART regimen (P = .025), younger age (P = .040), lower liver stiffness (P = .010), and quantitative HBsAg < log10 2.0 IU/mL (P = .001). All 5 factors remained significant in a Cox regression analysis that adjusted for baseline CD4 count. High HBsAg loss rates occur in PWH and HBV early after commencing ART. Our study suggests that TAF-containing ART regimens may be preferable as first-line therapy in HIV-HBV coinfection.