Disease relevance of Entecavir

• Metabolic studies on BMS-200475, a new antiviral compound active against hepatitis B virus [1].
• WHV viremia in BMS-200475-treated WHV carriers eventually returned to pretreatment levels after therapy was stopped [2].
• The results indicate that BMS-200475 therapy reduced mean WHV titers by 10(7)- to 10(8)-fold, down to levels as low as 10(2) to 10(3) virions/ml of serum [2].
• SEARCH METHODOLOGY: Computerized searches of PubMed and International Pharmaceutical Abstracts from 1985 to July 10, 2005, were performed with the search headings: entecavir, BMS-200475, and chronic hepatitis B [3].
• The probability for HBV DNA suppression was not reduced in patients with adefovir or entecavir resistance or in patients with advanced liver disease [4].

High impact information on Entecavir

• Potent efficacy of entecavir (BMS-200475) in a duck model of hepatitis B virus replication [5].
• Within 4 weeks of daily therapy with 0.5 or 0.1 mg of BMS-200475 per kg, endogenous viral polymerase levels in serum were reduced about 1,000-fold compared to pretreatment levels [2].
• In the HepG2 stably transfected cell line 2.2.15, BMS-200475 had a 50% effective concentration (EC50) of 3.75 nM against HBV, as determined by analysis of secreted HBV DNA [6].
• From the molecular modeling study the hydroxymethyl side chains of BMS-200475 (3) and 4c were almost overlapped, indicating that 4c may be suitable for phosphorylation by cellular kinases like the lead 3, but some discrepancy between two bases was observed, indicating why 4c is less potent against HBV than 3 [7].

Associations of Entecavir with other chemical compounds

• Among 'Responders' who discontinued treatment after 48 weeks, 7/257 (3%) entecavir-treated and 10/201 (5%) lamivudine-treated patients sustained HBV-DNA below 300copies/mL at 24-weeks off-treatment [8].
• Two lamivudine-experienced patients demonstrated the rtM204I mutation; no other entecavir-resistant substitutions were detected (rtI169, rtT184, rtS202, and rtM250) [9].
• Patients with lamivudine-resistant mutations at the start of entecavir monotherapy had a reduced probability of achieving VR compared to lamivudine-naïve patients (HR 0.14; 95% CI 0.04-0.58; p=0.007) [10].
• By week 48, 7 (19%) patients in the entecavir group and 5 (4%) patients in the lamivudine group died (adjusted hazard ratio 5.1, 95% confidence interval 1.5-17.2, p=0.010) [11].

Analytical, diagnostic and therapeutic context of Entecavir

• Intracellular HBV replicative intermediates were uniformly reduced when cells were treated with BMS-200475, but rebounded after treatment was terminated [6].
• Southern blot hybridization analysis of liver biopsy samples taken from animals during and after BMS-200475 treatment showed remarkable reductions in the levels of WHV DNA replicative intermediates and in the levels of covalently closed circular viral DNA [2].
• These results indicate that BMS-200475 should be evaluated in clinical trials for the therapy of chronic human hepatitis B virus infections [2].
• The concentration of BMS-200475 causing 50% cytotoxicity in 2.2.15 cell cultures was 30 microM, approximately 8,000-fold greater than the concentration required to inhibit HBV replication in the same cell line [6].

References