And the communication I have got to make is, that (it) has great expectations.
-Charles Dickens Great ExpectationsChronic infection by hepatitis B virus (HBV) affects approximately 400 million people worldwide and is estimated to cause 1 million deaths annually [1]. The treatment of chronic hepatitis B has been radically altered in the past decade as a result of two developments. First, there are important new findings concerning its natural history. Second, the oral nucleoside/nucleotide analogues are now firmly established as an excellent alternative mode of therapy.Studies of the natural history of chronic hepatitis B suggest that other than the traditional endpoint of hepatitis B e antigen (HBeAg) seroconversion, sustained suppression of HBV DNA to very low levels, preferably to below the detection limit of sensitive polymerase chain reaction (PCR) assays, is an even more important endpoint of treatment [2][3][4][5]. The availability of nucleoside/nucleotide analogues makes the ideal of sustained viral suppression a reality. The rate of HBeAg seroconversion is slower with nucleoside/nucleotide analogues than with interferon therapy because they lack the immunomodulatory effects of interferon. Unlike interferon, nucleoside/nucleotide analogues can be given orally, and, except for mild and reversible nephrotoxicity (approximately 3% in 5 years) with adefovir [6], are almost without side effects. Even a relatively short period of treatment with lamivudine has been shown to decrease the risk for the development of cirrhosis complications and hepatocellular carcinoma (HCC) both in patients with established cirrhosis and in patients with precirrhotic disease [7,8]. The problem with long-term nucleoside/nucleotide analogue therapy is of course the potential for the development of resistant mutants.One of the most promising nucleoside analogues for long-term viral suppression with low rate of development of resistance is entecavir. Entecavir is a deoxyguanosine analogue that is rapidly phosphorylated intracellularly into its active 5 0 -triphosphate form. It inhibits HBV replication at three important steps: protein-linked priming of the HBV polymerase, synthesis of the first negative strand of the HBV DNA by reverse transcription, and synthesis of the second positive strand [9]. Its efficient phosphorylation and its triple action in the inhibition of HBV replication may explain its potency in the suppression of HBV DNA in small doses of 0.5-1 mg licensed for use. It has been approved for use in the treatment of chronic hepatitis B in the United States in 2005, and since then in the European Union, China, and several other countries worldwide.In the current issue of the journal, Shindo et al.[10] report a randomized, double-blind phase II study of the antiviral activity of once-daily oral dose of entecavir 0.01, 0.1, or 0.5 mg, or lamivudine 100 mg, over 24 weeks in 137 nucleoside-naive Japanese adults. This study confirmed the results of an international study of 169 patients including Asians and Westerners publish...