Efficacy of Adefovir Dipivoxil for One year

in Patients With Lamivudine-Resistant

Chronic Hepatitis B

Juri Jeong°, Kyung Jin You,Yang Suk Na, Young Cheon Song

Department of Pharmacy, Asan Medical Center

Background & Aims : Drug resistance is a major concern during nucleotide

analogues therapy in patients with chronic hepatitis B virus infections. Adefovir dipivoxil is effective in patients with lamivudine-resistant hepatitis B virus(HBV). This study assessed the efficacy of adefovir dipivoxil in patients with chronic hepatitis B and lamivudine-resistant hepatitis B virus (HBV).

Methods : We assigned 79 patients to treat with lamivudine for at least 1 year,to result first positive on lamivudine-resistant test between June 2006 and July 2006, and to follow up more than 1 year. The primary end point was reduction in the serum HBV DNA level, HBeAg loss and seroconversion, and reduction of the ALT level. Secondary end points included YMDD mutation type of lamivudine-resistant test, change to be on medication.

Results : Rapid reductions in serum HBV DNA level were seen by 8 months in adefovir dipivoxil than with lamivudine. And ALT level reduction from baseline at 3 months was greater with adefovir than with lamivudine, mean variation from baseline in serum ALT level of adefovir group at 3, 4, 5, 6, 7, 10, 11 months was also greater (p < 0.05). Genotypic analyses of HBV polymerase performed on all 79 patients had lamivudine resistance mutations by sequencing at baseline. The M204I single mutations occurred most frequently (in 32.9% of these patients) and M204I + L180M double mutations were detected in 25(31.7%). After 1 year, the percentage of to be on medication that was lamivudine group decreased by 22.26 % and was adefovir group increased by 15.26%.

Conclusions : These data indicate that adefovir dipivoxil therapy provides effective antiviral therapy in patients with lamivudine-resistant HBV.