Clinical trial: effects of adefovir dipivoxil therapy in Asian and Caucasian patients with chronic hepatitis B S. G. LIM*, P. MARCELLIN  , N. TASSOPOULOS à , S. HADZIYANNIS§, T. T. CHANG – , M. TONG**, W. SIEVERT   , P. HU àà , S. ARTERBURN§§ & C. L. BROSGART§§ ON BEHALF OF THE INTERNATIONAL INVESTIGATOR GROUPS FOR STUDIES 437 AND 438 *National University Hospital, Singa- pore;  Hospital Beaujon, Paris, France; àDepartment of Hepatology, Metropolitan Hospital, Athens, Greece; §Henry Dunant Hospital, Liver Research Unit, Athens, Greece; –National Cheng Kung University Hospital, Tainan, Taiwan; **Hunting- ton Memorial Hospital, Pasadena, CA, USA;   Monash Medical Center, Victoria, Australia; ààPeking Union Medical College Hospital, Peking, PRC; §§Gilead Sciences, Inc, Foster City, CA, USA Correspondence to: Dr S. G. Lim, Department of Medicine, Division of Gastroenterology, National University Hospital, 5 Lower Kent Ridge Road, Singapore 119074, Singapore. E-mail: mdclimsg@nus.edu.sg Publication data Submitted 6 April 2007 First decision 23 April 2007 Resubmitted 27 July 2007 Second decision 7 August 2007 Resubmitted 31 August 2007 Accepted 01 September 2007 SUMMARY Background Two-thirds of the 350 million people infected with chronic hepatitis B virus live in the Asia-Pacific region. Aim To compare the effects of adefovir dipivoxil therapy between Asian and Caucasian patients with chronic hepatitis B. Methods The safety and efficacy of 10 mg of adefovir dipivoxil was compared to placebo in 501 Asian (n = 259) or Caucasian (n = 242) HBeAg+ and HBeAg) chronic hepatitis B virus patients treated for 48 weeks in two randomized, double-blind, placebo-controlled studies. Results At week 48, histological improvement was observed in 60% and 56% of Caucasian and Asian patients, respectively. Change in serum hepatitis B virus DNA from baseline to week 48 for the adefovir dipivoxil-treated patients was )3.89 and )3.70 log 10 copies ⁄ mL in Caucasian and Asian patients, respectively, while 34 per cent of Caucasian patients and 39 per cent of Asian patients had undetectable serum hepatitis B virus DNA (<400 copies ⁄ mL) at week 48. The percentage of patients achieving alanine aminotransferase (ALT) normalization at week 48 was similar in both groups (Caucasian 64 per cent, Asian 63 per cent). No patients developed resistance through week 48. No differences in adverse events or grade 3 or 4 laboratory abnormalities were observed between groups. Conclusions There were no significant differences in treatment response between Asians and Caucasians. Adefovir dipivoxil was well tolerated and no resistance developed up to week 48 in both racial groups. Aliment Pharmacol Ther 26, 1419–1428 Alimentary Pharmacology & Therapeutics ª 2007 The Authors 1419 Journal compilation ª 2007 Blackwell Publishing Ltd doi:10.1111/j.1365-2036.2007.03506.x