Entecavir: A potent new antiviral drug for Hepatitis B
ABSTRACT Entecavir, a new deoxyguanine nucleoside analogue, is a selective inhibitor of the replication of the hepatitis B virus. In vitro this compound has proven to be far more effective than other nucleoside analogues. In animal models, an impressive reduction of serum viral DNA has been observed with covalently closed circular DNA and hepatitis B viral core antigen negativity in liver biopsy specimens. In clinical studies, entecavir revealed excellent suppression of hepatitis B virus replication without significant side effects or evidence of mitochondrial toxicity. Until now, no entecavir-resistant viral mutants have been described. Prolonged therapy as well as prophylactic therapy, for example, in liver transplant recipients, is feasible and not limited by breakthrough infections. Data on entecavir therapy for treatment of nucleoside-naive, wild-type hepatitis B virus is being generated in Phase III clinical trials worldwide for both hepatitis B envelope antigen-positive and -negative subpopulations, as well as in lamivudine-resistant patients. Based on mechanism and potency of interferon and entecavir, clinical trials with combination therapy are eagerly awaited.
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- "Entecavir is a carboxylic analogue of guanosine and is the most recently FDA approved drug for the treatment of chronic Hepatitis B. Like Adefovir, it has been shown to be a potent antiviral agent for the wild type and LAM-resistant forms of chronic HBV. [84-86] It is expected that Entecavir will be efficacious in the prevention and treatment of recurrent HBV following liver transplantation. The first reports of Entecavir's use in this setting are now being reported. "
ABSTRACT: The Hepatitis B virus (HBV) is a DNA virus that can cause both acute and chronic liver disease in humans. Approximately 350-400 million people are affected worldwide and up to one million deaths occur annually from cirrhosis and hepatocellular carcinoma. When cirrhosis and liver failure develop, the definitive treatment of choice remains orthotopic liver transplantation (OLT). In the past, an unacceptable HBV recurrence rate with a high rate of graft loss was noted. The use of Hepatitis B immunoglobulin (HBIG) has resulted in improved patient and graft survival rates. The addition of the nucleoside analog Lamivudine (LAM) to HBIG has improved these survival curves to an even greater degree. Prolonged use of LAM will almost invariably lead to the development of viral mutations resistant to the drug. There are now several other nucleoside and nucleotide analogs (Adefovir, Entecavir, Tenofovir, and Truvada) available for the clinician to utilize against these resistant strains. It should be possible to prevent recurrence in most, if not all, post-transplant patients and also to significantly reduce viral loads with normalization of transaminases in those who have developed recurrent infection. The antiviral regimen should be robust and minimize the risk of breakthrough mutations. A prudent approach may be the implication of combination antiviral therapy. This review summarizes the efficacy of previous regimens utilized to prevent and treat recurrent HBV following OLT. Particular attention will be paid to the newer nucleoside and nucleotide analogs and the direction for future strategies to treat HBV in the post transplant setting.Annals of Clinical Microbiology and Antimicrobials 02/2006; 5(1):8. DOI:10.1186/1476-0711-5-8 · 1.51 Impact Factor
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ABSTRACT: Chronic hepatitis B remains a public health problem of global importance despite the availability of an effective vaccine. Between 350 and 400 million people, approximately 6% of the world's population, suffer from chronic hepatitis B and face a 30% likelihood of developing cirrhotic liver disease or hepatocellular carcinoma. Current treatment options include three monotherapies of subcutaneous interferon, oral nucleoside lamivudine and oral nucleotide adefovir dipivoxil. Unfortunately, these agents have not effectively and frequently been able to attain a 'cure' or complete eradication of the virus. Consequently, the expectation of current therapies is confined to the achievement of clinically beneficial and durable responses defined by lasting suppression of virus replication, histological improvement and increased survival for patients with decompensated liver diseases. Other disadvantages include the undesirable tolerability of interferon, the rapid resistance to lamivudine and the compromise between efficacy and toxicity that led to the development of the 10 mg dose of adefovir dipivoxil. Clearly, better therapeutics and treatment strategies are needed. Increased potency, activity against current treatment-refractory viruses, as well as efficacy in difficult-to-treat populations will be critical to meeting the therapeutic challenge of chronic hepatitis B.Expert Opinion on Investigational Drugs 09/2003; 12(8):1281-95. DOI:10.1517/135437184.108.40.2061 · 5.43 Impact Factor