Adefovir is an acyclic monophosphate adenine analogue which was approved for the treatment of chronic hepatitis B at a dose of 10 mg/day in 2002. Worldwide, there have been an estimated 410,000 patient-years of adefovir use through 2008 . ADV is a potent and widely-used anti-HBV drugs in Asian countries, and this drug has potent antiviral efficacy in nucleoside-naïve patients with CHB, resulting in significant virological, biochemical, and histological improvement [15–18]. A randomized, double-blind, placebo-controlled, prospective study conducted by Dong PL et al, showed that ADV could effectively suppress HBV DNA and normalize ALT at week 48 . Entecavir is a carboxylic 2'-deoxyguanosine analogue, and is approved in the US, EU and many Asian countries . The recommended once-daily oral dosage of entecavir is 0.5 mg in nucleos(t)ide-naïve patients. In the ETV-023 study conducted in China, entecavir treatment provided better efficacy than lamivudine at 48 weeks in terms of the composite primary endpoint in a mixed population of HBeAg-positive or -negative patients .
In our study, we compared the efficacy between the two drugs in suppressing HBV DNA, normalizing ALT, clearing HBeAg and encouraging HBeAg seroconversion with the method of meta-analysis, and found out that for the HBeAg-positive nucleos(t)ide-naive Asian CHB patients, ETV exhibited better efficacy than ADV at 48 weeks in suppressing HBV DNA and normalizing ALT, however, in clearing HBeAg and encouraging HBeAg seroconversion, the efficacy between the two drugs was similar. It is a consensus that clearance of HBeAg and/or development of anti-HBe are associated with improved outcomes , so, for Asian population, ADV treatment is not inferior to ETV treatment in all aspects for assessment of anti-HBV therapy. Owing to the cost benefit in the long-term experience and safety, particularly in Asian countries , it is confirmed that ADV can be still used for first-line therapy in the HBeAg-positive nucleos(t)ide-naive patients with CHB.
In conclusion, entecavir is superior to adefovir in decreasing serum HBV DNA and normalizing ALT, but similar with adefovir in clearing HBeAg and encouraging HBeAg seroconversion for the HBeAg-positive nucleos(t)ide-naive Asian patients with chronic hepatitis B. Adefovir can be still used for first-line therapy in these patients.