Long-term safety of lamivudine treatment in patients with chronic hepatitis B

Background & Aims: Data on the long-term safety of lamivudine are limited. The aim of this analysis was to determine the incidence of hepatitis flares, hepatic decompensation, and liver-disease-related (LDR) serious adverse events (SAE) during long-term lamivudine treatment. Methods: We reviewed data on 998 patients with HBeAg-positive compensated chronic hepatitis B who received lamivudine for up to 6 years (median, 4 years) and 200 patients who received placebo for 1 year. Results: Hepatitis flares occurred in 10% of the lamivudine-treated patients in year 1 and in 18%-21% in years 2-5. A temporal association between hepatitis flares and lamivudine-resistant mutations increased from 43% in year 1 to >80% in year 3. Ten hepatic decompensation events occurred in 8 (<1%) lamivudine-treated patients. Fifty-three (5%) lamivudine-treated patients experienced a total of 60 LDR SAEs. Four patients died, 2 from liver-related causes. The proportion of patients with a documented lamivudine-resistant mutation increased from 23% in year 1 to 65% in year 5. During each year of the study, patients with lamivudine-resistant mutations experienced significantly more hepatitis flares than patients without lamivudine-resistant mutations (P < 0.005). The occurrence of hepatic decompensation (0%-2%) and LDR SAEs (1%-10%) among patients with lamivudine resistance remained stable during the first 4 years with mutations and increased afterward to 6% (P = 0.03) and 20% (P = 0.009), respectively. Conclusions: This study demonstrated that lamivudine treatment for up to 6 years has an excellent safety profile in patients with HBeAg-positive compensated liver disease, but patients with long-standing lamivudine-resistant mutations may experience worsening liver disease.