Tenofovir disoproxil fumarate (TDF) versus Emtricitabine plus TDF for treatment of chronic Hepatitis B (CHB) in subjects with persistent viral replication receiving Adefovir dipivoxil (ADV)

A Cost-Utility and Cost-Effectiveness Analysis of Different Oral Antiviral Medications in Patients With HBeAg-Negative Chronic Hepatitis B in Iran: An Economic Microsimulation Decision Model

BACKGROUND

Although hepatitis B infection is the major cause of chronic liver disease in Iran, no studies have employed economic evaluations of the medications used to treat Iranian patients with chronic hepatitis B (CHB). Therefore, the cost-effectiveness of the different treatment options for this disease in Iran is unknown.

OBJECTIVES

The aim of this study was to compare the cost utility and cost-effectiveness of medication strategies tailored to local conditions in patients with HB e antigen (HBeAg)-negative CHB infection in Iran.

METHODS

An economic evaluation of the cost utility of the following five oral medication strategies was conducted: adefovir (ADV), lamivudine (LAM), ADV + LAM, entecavir (ETV), and tenofovir (TDF). A Markov microsimulation model was used to estimate the clinical and economic outcomes over the course of the patient's lifetime and based on a societal perspective. Medical and nonmedical direct costs and indirect costs were included in the study and life-years gained (LYG) and quality-adjusted life-years (QALY) were determined as measures of effectiveness. The results are presented in terms of the incremental cost-effectiveness ratio (ICER) per QALY or LYG. The model consisted of nine stages of the disease. The transition probabilities for the movement between the different stages were based on clinical evidence and international expert opinion. A probabilistic sensitivity analysis (PSA) was used to measure the effects of uncertainty in the model parameters.

RESULTS

The results revealed that the TDF treatment strategy was more effective and less costly than the other options. In addition, TDF had the highest QALY and LYG in the HBeAg-negative CHB patients, with 13.58 and 21.26 (discounted) in all comparisons. The PSA proved the robustness of the model results. The cost-effectiveness acceptability curves showed that TDF was the most cost-effective treatment in 59% - 78% of the simulations of HBeAg-negative patients, with WTP thresholds less than $14010 (maximum WTP per QALY).

CONCLUSIONS

The use of TDF in patients with HBeAg-negative CHB seemed to be a highly cost-effective strategy. Compared with the other available medication options, TDF was the most cost-saving strategy. Thus, TDF may be the best option as a first-line medication. Patients can also be switched from other medications to TDF.

Mixed treatment comparison meta-analysis evaluating the relative efficacy of nucleos(t)ides for treatment of nucleos(t)ide-naive patients with chronic hepatitis B

BACKGROUND/AIMS

Five nucleoside/nucleotide treatments are now available for chronic hepatitis B (CHB). This meta-analysis aimed to assess the relative efficacy of adefovir, entecavir, lamivudine, telbivudine, tenofovir disoproxil fumarate (TDF), and nucleos(t)ide combinations in the treatment of CHB.

METHODS

A systematic review of MEDLINE and the Cochrane library was conducted to identify all studies evaluating these nucleos(t)ides in adults with CHB. Randomized controlled trials were included in the meta-analysis if they reported the proportion of patients with undetectable hepatitis B virus (HBV) DNA or hepatitis B e antigen (HBeAg) loss/seroconversion at 1 year. Bayesian mixed treatment comparison meta-analyses were conducted in WinBUGS to assess relative efficacy.

RESULTS

A random-effects meta-analysis of trials on treatment-naive patients with HBeAg-positive CHB demonstrated that 94% of patients will achieve HBV DNA < 300 copies/ml after 1 year with TDF, compared with 73% for entecavir, 50% for adefovir, and 38% for lamivudine. There was a 97.7% probability that TDF enabled a greater proportion of patients to achieve HBV DNA < 300 copies/ml at 1 year than all other treatments considered in the analysis. TDF was significantly superior to all nucleos(t)ides for this outcome at the 0.05 level. There were no statistically significant differences between nucleos(t)ides in HBeAg seroconversion at 1 year, based on a fixed-effects meta-analysis in the same population. More trials on HBeAg-negative and drug-resistant patients are required to facilitate meta-analyses for these subgroups.

CONCLUSIONS

In nucleos(t)ide-naive patients with HBeAg-positive CHB, TDF is associated with the highest probability of achieving undetectable HBV DNA at 1 year of all nucleos(t)ides considered.

Cost-utility analysis of tenofovir disoproxil fumarate in the treatment of chronic hepatitis B

OBJECTIVE

The aim of this study was to assess the cost-effectiveness of tenofovir disoproxil fumarate (TDF) in the treatment of chronic hepatitis B (CHB) versus alternative nucleos(t)ides from a UK National Health Service (NHS) perspective.

METHODS

A Markov model was used to calculate costs and benefits of nucleos(t)ide strategies in hepatitis B e antigen (HBeAg)-positive and HBeAg-negative patients with hepatitis B virus mono-infection and compensated liver disease. The model included 18 disease states representing CHB progression. Quality-of-life data and costs for severe disease states were based on published studies, while monitoring costs for other disease states were based on expert opinion. Transition probabilities for movements between states were based on a meta-analysis, clinical trials, and natural history studies.

RESULTS

First-line TDF generated the highest net benefits of all 211 nucleos(t)ide strategies evaluated at a threshold of £ 20,000 per quality-adjusted life-year (QALY) gained. First-line TDF cost £ 19,084/QALY gained compared with giving lamivudine (LAM) first-line and switching to TDF when LAM resistance occurs. First-line TDF was also more effective and less costly than first-line entecavir (ETV), and showed extended dominance over first-line adefovir and strategies reserving adefovir, ETV, or combination therapy until after LAM resistance develops. For patients who have developed LAM resistance, TDF was also the most cost-effective treatment, generating greater net benefits than any other second-line strategy.

CONCLUSIONS

First-line TDF is the most cost-effective treatment for patients with CHB at a £ 20,000 to £ 30,000/QALY ceiling ratio, costing £ 19,084/QALY gained compared with the next best alternative.

Role of combination therapy in chronic hepatitis B

Combination therapy includes the use of two or more antivirals for the treatment of chronic hepatitis B. No study has shown that combination therapy is superior to monotherapy in naive patients for achieving treatment end points, but combination appears to result in a lower incidence of resistance. Moreover, the higher-potency compounds have not yet been studied. Consideration should be given to treating lamivudine-resistant patients with combination therapy, preferably with a nucleotide analogue in conjunction with a nucleoside analogue. Combination therapy should be considered in patients with decompensated cirrhosis who are unable to achieve an undetectable viral level on monotherapy and in naive patients who still have a detectable viral level 6 to 12 months after starting therapy.