Viral Suppression and Cirrhosis Regression with Tenofovir Disoproxil Fumarate in Asians with Chronic Hepatitis B

Background Chronic hepatitis B (CHB) is a major public health concern, particularly in endemic areas like Asia-Pacific. Sustained virologic suppression correlates with regression of histologic fibrosis and cirrhosis. Aim This study evaluated efficacy and safety of tenofovir disoproxil fumarate (TDF) in Asian patients through 240 weeks of treatment. Methods Post hoc analysis of the Asian subpopulation from two phase 3 clinical studies was performed. Following a 48-week randomized, double-blind evaluation of once-daily TDF versus once-daily adefovir dipivoxil, openlabel TDF for up to 240 weeks was evaluated. Patients with both baseline and week 240 liver biopsies were evaluated for histologic changes. Results At baseline, 189/641 (29 %) patients randomized were Asian. Sixty-eight percent of Asian patients were male; 50 % were hepatitis B e antigen (HBeAg)-positive. At week 240, similar proportions of Asian (88 %) and nonAsian (87 %) patients demonstrated improvement in liver histology, and 19/22 (86 %) Asian patients with baseline cirrhosis were no longer cirrhotic. By modified intent-totreat analysis, 74 % of Asian patients and 76 % of nonAsian patients had HBV DNA <400 copies/mL at the end of week 240 (P = 0.602). No differences were seen in HBeAg loss or seroconversion in Asian versus non-Asian patients. No Asian patient experienced hepatitis B surface antigen loss. Safety and tolerability of TDF through week 240, including changes in renal function and in hip/spine bone mineral density (from weeks 192 to 240), were comparable between Asian and non-Asian patients. Conclusions Long-term virologic and histologic efficacy and safety of TDF are comparable in Asian and non-Asian CHB patients.