Clinical trial: a phase II, randomized study evaluating the safety, pharmacokinetics and anti-viral activity of clevudine for 12 weeks in patients with chronic hepatitis B.

BACKGROUND: Clevudine is a polymerase inhibitor that has the unusual feature of delayed viral rebound after therapy in some patients which may be related to its pharmacokinetics. AIM: To characterize pharmacokinetic and pharmacodynamic profile of clevudine, a potent hepatitis B polymerase inhibitor. METHODS: A multicenter, randomized study comparing 10, 30 and 50 mg clevudine once daily for 12 weeks with 24 weeks off-treatment follow-up. Patients had chronic HBV infection, were nucleoside-naïve without co-infection. HBV viral load (VL) was assayed using Digene Hybrid Capture II with a lower limit of detection of 4700 copies/mL (940 IU/mL). Clevudine levels were measured using a liquid chromatography/mass spectrometery method. RESULTS: A total of 31 patients were enrolled into the 10 mg (n = 10), 30 mg (n = 11) and 50 mg (n = 10) groups, respectively. At week 12, the median VL change was -3.2, -3.7 and -4.2 log(10) copies/mL (-0.64, -0.74 and -0.84 log(10) IU/mL) in the 10, 30 and 50 mg groups, respectively (P = 0.012). At week 12, one of 10, five of 11 and two of 10 patients had VL below the assay lower limit of detection. Clevudine was well tolerated with no severe/serious adverse events. The mean plasma half-life of clevudine was 70 h and consequently is not the cause of the delayed viral rebound seen in some patients. Through modelling, 97% of the maximal treatment effect was reached with a 30 mg daily dose. Six patients had genomic changes without viral rebound. CONCLUSION: Clevudine appears to be a potent and tolerable (over 12 weeks) anti-viral and the optimal dosage appears to be 30 mg once daily.

Active antiviral therapy for chronic hepatitis B and hepatocellular carcinoma.

The ultimate goal of treatment for chronic hepatitis B (CHB) is to prevent hepatocellular carcinoma (HCC). During the last decade, great strides have been made in the treatment of hepatitis B virus (HBV) infections. Six highly effective anti-HBV agents are currently available and more agents are on the horizon. Prospective and retrospective studies of large numbers of CHB patients with advanced liver disease, including cirrhosis, have demonstrated that the treatment with lamivudine not only delays the disease progression but also reduces the incidence of HCC. In a large prospective study of 3,653 HBV carriers in Taiwan, 164 persons developed HCC in a 12-year follow-up period; an extensive analysis of their condition led to the conclusion that the most important risk factor for HCC is an increased serum level of HBV DNA >10,000 copies/mL regardless of the HBeAg status, alanine aminotransferase levels or presence of cirrhosis. The incidence of HCC correlated with serum HBV DNA level at entry in a dose-response relationship. These pivotal studies re-emphasize the need for an active anti-HBV therapy for CHB patients with viral replication as the ultimate prevention and/or delay for the development of HCC.

Histological outcome during long-term lamivudine therapy.

BACKGROUND & AIMS: One year of lamivudine for chronic hepatitis B results in histologic improvement. We aimed to assess the histological impact of longer-term treatment. METHODS: Sets of 3 liver biopsies, from 63 patients before and after 1 year of randomized lamivudine treatment and after 2 years of further open-label treatment, were assigned Histologic Activity Index scores under code. RESULTS: At the end of year 1, 36/63 (57%) showed > or =2 point improvement and 24/63 (38%) no change in necroinflammatory activity; after 2 additional years of lamivudine, 38/63 (60%) remained stable and 12/63 (19%) continued to improve. Worsening occurred in similar proportions of patients with and without YMDD (tyrosine, methionine, aspartate, aspartate) variants. After all 3 years of lamivudine treatment, 35/63 (56%) of patients showed improvement, 21/63 (33%) no change, and 7/63 (11%) worsening. Those without, compared with those with, YMDD variants were more likely to improve (17/22 [77%] vs. 18/41 [44%]) and less likely to deteriorate (1/22 [5%] vs. 6/41 [15%]). Patients with YMDD variants for >2 years were least likely to improve (8/22 [36%]). Bridging fibrosis improved by > or =1 level in 12/19 (63%), and cirrhosis improved (score of 4 to < or =3) in 8/11 (73%). Only 1/52 [2%]) showed progression to cirrhosis, and 3/34 (9%) showed progression to bridging fibrosis (all with YMDD variants). CONCLUSIONS: Three years of lamivudine therapy reduces necroinflammatory activity and reverses fibrosis (including cirrhosis) in most patients. The emergence of YMDD variants blunts histologic responses; therefore, extended-duration YMDD variants may require additional therapies to maintain the histological benefit of treatment.