Cost is a major issue with regard to treatment of chronic hepatitis B virus (HBV) infection. Lamivudine (Epivir-HBV) and adefovir (Hepsera) are commonly prescribed options, but their long-term efficacy is limited by the emergence of drug-resistant virus.

As reported at the 43rd annual meeting of the European Association for the Study of the Liver (EASL 2008) last month in Milan, Spanish researchers undertook the task of predicting long-term cost and health outcomes of treating chronic hepatitis B in treatment-naive, HBeAg negative patients, comparing the 4 most frequently prescribed drugs for first-line treatment of this patient population in Spain: lamivudine (Epivir-HBV), adefovir (Hepsera), entecavir (Baraclude), and tenofovir (Viread).

European drug regulators recently approved tenofovir for treatment of chronic hepatitis B in the countries of the European Union, but it is not yet FDA-approved for this indication in the U.S.

In the present study, the researchers developed a simulation model to predict disease progression, incidence and cost of chronic hepatitis B-related complications according to HBV DNA viral suppression achieved with different treatments over time.

Patients were assigned levels of viral suppression and risk of developing viral resistance specific to their first-line treatment. Individuals who developed resistant to treatment could switch or add on another drug. Patients who developed resistance to first- and second-line treatments were assumed to discontinue treatment, and disease progression rates assumed no further viral suppression.

Three categories of HBV DNA suppression were considered to predict incidence of complications:

• Full response: < 300 copies/mL;

• Partial response: 300-105 copies/mL;

• Non-response: > 105 copies/mL.

Complications included compensated cirrhosis, decompensated cirrhosis, and hepatocellular carcinoma (HCC). Patients who developed decompensated cirrhosis or HCC were eligible for liver transplantation.

Patients remained within the simulation model until HBsAg seroconversion or death from either HBV-related complications or natural causes. Costs of managing chronic hepatitis B and complications reflected clinical practice in Spain. All clinical and epidemiological inputs were obtained from published literature.

The analysis was conducted using 1000 simulated patients over a 30 year time horizon reflecting the chronicity of HBV infection.

Results

• In first-line treatment, tenofovir was predicted to be more effective and less expensive compared with lamivudine and adefovir.

• Tenofovir was predicted to provide similar health outcome at lesser medical costs compared with entecavir.

Based on their findings, the researchers concluded, "When considering a first-line treatment option in Spain, tenofovir is predicted to be one of the most cost-effective treatments compared to lamivudine, adefovir, and entecavir."

United BioSource Corporation, Concord, MA; Department of Hepatology, Hospital Vall D Hebron, Barcelona, Spain; Oblikue Consulting, Barcelona, Spain; Pharmacoeconomics & Outcomes Research Iberia, Madrid, Spain; Gilead Sciences, Foster City, CA.

5/09/08

Reference
B Deniz, M Buti, M Brosa, and others. Cost-effectiveness simulation analysis of tenofovir disoproxil fumarate (tenofovir), lamivudine, adefovir dipivoxil (adefovir) and entecavir of HeAg negative (-) patients with chronic hepatitis-B (CHB) in Spain. 43rd annual meeting of the European Association for the Study of the Liver (EASL 2008). Milan, Italy. April 23-27, 2008.