Abstract

The prevalence and morbidity of hepatitis B virus (HBV) infection is high in Africa. Scale-up of treatment with the use of nucleos(t)ide analogs (NAs) with high barrier to resistance such as entecavir (ETV), tenofovir disoproxil fumarate (TDF), or tenofovir alafenamide (TAF) may help curtail the disease burden in sub-Saharan Africa. However, limited accessibility to these NAs and limitations of ETV (development of resistance in lamivudine-exposed patients), and TDF (decline in renal function and bone mineral density with long-term use) act as barriers to optimization of HBV treatment in this region. Therefore, a panel of 9 (nine) hepatology experts from Africa convened, reviewed the literature, and developed the current position statement for use of TAF in resource-limited African settings. This article presents an overview of the efficacy and safety of TAF versus TDF in both HBeAg-negative and HBeAg-positive chronic HBV patients. Studies have revealed non-inferiority for the proportion of patients who had HBV DNA <29IU/mL; higher rate of normalization of alanine aminotransferase levels; and better bone/renal safety, with TAF vs. TDF up to 144weeks. Tenofovir alafenamide has better renal/bone safety compared to TDF, due to its less systemic exposure of tenofovir and greater exposure of tenofovir diphosphate to target cells. In view of these benefits of TAF, the expert panel proposed indications for scale-up of the use of TAF, specifically in patients with renal/bone health issues, in Africa. Optimization of use of TAF in the proposed patient population may help in lowering the prevalence and morbidity from HBV in Africa.

Keywords

HBV, hepatitis B virus, NAs, nucleos(t)ide analogs, TAF, tenofovir alafenamide, TDF, tenofovir disoproxil fumarate, ETV, entecavir, WHO, world health organization, HBsAg, hepatitis B surface antigen, HBIG, hepatitis B immunoglobulin G, ALT, alanine aminotransferase, AASLD, american association for the study of liver diseases, ULN, upper limit of normal, LAM, lamivudine, YMDD, tyrosine-methionine-aspartate-aspartate, hepatitis B virus, nucleoside analogs, Tenofovir alafenamide, Africa