Introduction of lamivudine for the treatment of chronic hepatitis B: expected clinical and economic outcomes based on 4-year clinical trial data.

BACKGROUND: Chronic hepatitis B (CHB) is associated with a significant burden of illness and treatment involves substantial health-care costs. This study estimates clinical outcomes and cost-effectiveness of lamivudine compared with other treatment scenarios for CHB, from an Australian health-care provider perspective.
METHODS: A two-step modeling approach depicted clinical progression of hepatitis B in hypothetical patient cohorts using three different treatment scenarios: scenario A, lamivudine and alpha-interferon (IFN-alpha) available; scenario B, IFN-alpha available only; and scenario C, no treatment available. Assumptions were based on clinical trials, published studies, a hepatologist's questionnaire and an expert panel follow up. One-year clinical outcomes and costs were estimated using a decision tree, while lifetime costs and outcomes were estimated using available clinical trial data for lamivudine (up to 4 years therapy duration) and a Markov model.
RESULTS: The analysis considered only patients with pretreatment elevated alanine aminotransferase levels > or = 2 x upper limit of normal. In the short term, the introduction of lamivudine is expected to result in almost 3.5 times more CHB patients receiving therapy (lamivudine or IFN-alpha) compared to IFN-alpha only (67% compared to 20%, respectively). Hence, scenario A subsequently doubled the seroconversion rate. The incremental cost-effectiveness ratio was $3341 Australian per additional seroconversion. Also, non-seroconverted lamivudine patients are less likely to progress to cirrhosis than those receiving IFN-alpha/no treatment. One-year progression to cirrhosis was estimated at 5.1% with scenario A, compared to 12.2% and 12.7%, scenarios B and C, respectively. From the long-term analysis, lamivudine is expected to increase life expectancy by years and reduce the lifetime risk of compensated cirrhosis, decompensated cirrhosis and hepatocellular carcinoma by 6%, 12% and 12%, respectively. Additionally, the introduction of lamivudine decreases lifetime costs by $548, thus making it a cost-saving and life-extending strategy. In both short- and long-term models, worst case scenarios in sensitivity analyses still associate lamivudine with a favorable cost-effectiveness ratio.
CONCLUSION: Introduction of lamivudine is expected to improve health outcomes in CHB patients, resulting in overall savings in health-care costs. In this model, compared with IFN-alpha only and no treatment, lamivudine allowed more CHB patients to be treated, increased the seroconversion rate, delayed disease progression and prolonged life expectancy.