Cost-Effectiveness and Cost Thresholds of Generic and Brand Drugs in a National Chronic Hepatitis B Treatment Program in China

Chronic liver disease and liver cancer associated with chronic hepatitis B (CHB) are leading causes of death among adults in China. Although newborn hepatitis B immunization has successfully reduced the prevalence of CHB in children, about 100 million Chinese adults remain chronically infected. If left unmanaged, 15–25% will die from liver cancer or liver cirrhosis. Antiviral treatment is not necessary for all patients with CHB, but when it is indicated, good response to treatment would prevent disease progression and reduce disease mortality and morbidity, and costly complications. The aim of this study is to analyze the cost-effectiveness of generic and brand antiviral drugs for CHB treatment in China, and assessing various thresholds at which a highly potent, low resistance antiviral drug would be cost-saving and/or cost-effective to introduce in a national treatment program. We developed a Markov simulation model of disease progression using effectiveness and cost data from the medical literature. We measured life-time costs, quality adjusted life years (QALYs), incremental cost-effectiveness ratios (ICERs), and clinical outcomes. The no treatment strategy incurred the highest health care costs ($12,932-$25,293) per patient, and the worst health outcomes, compared to the antiviral treatment strategies. Monotherapy with either entecavir or tenofovir yielded the most QALYs (14.10–19.02) for both HBeAg-positive and negative patients, with or without cirrhosis. Threshold analysis showed entercavir or tenofovir treatment would be cost saving if the drug price is $32–75 (195–460 RMB) per month, highly cost-effective at $62–110 (379–670 RMB) per month and cost-effective at $63–120 (384–734 RMB) per month. This study can support policy decisions regarding the implementation of a national health program for chronic hepatitis B treatment in China at the population level.

Long-term adefovir dipivoxil monotherapy for up to 5 years in lamivudine-resistant chronic hepatitis B

BACKGROUND

Large clinical studies assessing long-term adefovir dipivoxil salvage monotherapy in patients with lamivudine-resistant chronic hepatitis B (CHB) are lacking, particularly in patients positive for hepatitis B e antigen (HBeAg). We assessed the efficacy and resistance profile of adefovir dipivoxil monotherapy for up to 5 years in a large cohort of Korean patients with lamivudine-resistant CHB.

METHODS

A total of 320 patients (81.3% HBeAg-positive; 100% genotype C) with confirmed genotypic lamivudine-resistant CHB were switched to adefovir dipivoxil 10 mg once daily. Liver function tests and HBV DNA were monitored every 3 months. Genotypic resistance to adefovir dipivoxil was performed in patients with detectable HBV DNA.

RESULTS

The overall cumulative virological response rate at 5 years of adefovir dipivoxil therapy was 48.8%. The virological response rate was significantly higher in HBeAg-negative patients (62.0% versus 45.9%; P=0.010). Most cases of virological response (131/134, 97.8%) occurred within the first 36 months of therapy. The 5-year cumulative probability of genotypic resistance and virological breakthrough was 65.6% and 61.8%, respectively. Predictive factors for a virological response included baseline HBeAg seronegativity, HBV DNA< or =8 log(10) copies/ml and achievement of an on-treatment initial virological response.

CONCLUSIONS

Adefovir dipivoxil salvage monotherapy for lamivudine-resistant CHB resulted in a modest cumulative virological response rate at 5 years, which was associated with progressive antiviral resistance. Consequently, adefovir monotherapy is not preferable as a first-line strategy for lamivudine resistance where combination lamivudine plus adefovir dipivoxil therapy is available.

Combination of baseline parameters and on-treatment hepatitis B virus DNA levels to start and continue patients with lamivudine therapy

Background

This study aimed to identify the baseline hepatitis B virus (HBV) DNA, alanine aminotransferase (ALT) levels and on-treatment HBV DNA levels for favourable outcome in patients receiving 5-year lamivudine.

Methods

Virological, serological and biochemical parameters were assessed in 74 hepatitis B e antigen (HBeAg)-positive chronic hepatitis B (CHB) patients at year 5 of therapy.

Results

Patients with baseline HBV DNA levels <9 log10 copies/ml and ALT≥2x the upper limit of normal (ULN) had a significantly higher chance of HBV DNA suppression to <4 log10 copies/ml (76.5%) and HBeAg seroconversion (82.4%), and a lower chance of YMDD mutations (35.3%) compared with patients with HBV DNA<9 log10 copies/ml and ALT<2xULN and patients with HBV DNA≥9 log10 copies/ml (all P<0.05). All patients with these two baseline parameters plus week 4 HBV DNA<4 log10 copies/ml achieved HBV DNA<35 copies/ml, HBeAg seroconversion and ALT normalization without YMDD mutations at year 5. When these two baseline parameters were combined with week 24 HBV DNA<3 log10 copies/ml, 60%, 80% and 90% of patients had HBV DNA<35 copies/ml, <3 log10 copies/ml and <4 log10 copies/ml, respectively at year 5. Overall, 90% of patients had HBeAg seroconversion and only 10% had YMDD mutations.

Conclusions

For HBeAg-positive patients with baseline HBV DNA<9 log10 copies/ml and ALT≥2xULN, lamivudine could be initiated. For those with HBV DNA<4 log10 copies/ml at week 4 or <3 log10 copies/ml at week 24, continuation of lamivudine treatment would be more likely to result in a good long-term response.

Comparison of the antiviral activity of adefovir and tenofovir on hepatitis B virus in HIV–HBV-coinfected patients

Background

Characteristics and factors influencing viral decay under tenofovir (TDF) and adefovir (ADV) need to be determined in HIV–HBV-coinfected patients.

Methods

This open-label study compared the HBV dynamics in 85 HIV–HBV-coinfected patients initiating an antiretroviral regimen, either including TDF or associated with ADV. The first 6-month change in viral load was analysed using mixed linear models. The adjusted hazards ratio, comparing the rates of undetectable HBV DNA between treatments, was calculated using a Cox proportional hazard model.

Results

The HBV DNA decay, adjusted for baseline HBV viral load was more pronounced in patients treated with TDF than with ADV at 12 months (66% versus 53%, P=0.0001). Patients in the TDF group presented a steeper slope of decline at 1.1 (95% confidence interval [CI] 0.9–1.3), compared with 0.8 (95% CI 0.6–1.0) in the ADV group ( P=0.036). The mean time to HBV DNA undetectability was 19.3 months (95% CI 16.7–22.0) with TDF and 25.9 months (95% CI 21.1–30.7) with ADV. When adjusted for hepatitis B virus e antigen, HBV DNA and alanine aminotransferase levels at baseline, the influence of treatment on time to HBV DNA undetectability remained in favour of TDF versus ADV (hazard ratio=2.79, 95% CI 1.05–7.40, P=0.039)

Conclusions

TDF influenced more strongly the early-phase HBV DNA kinetics than ADV. This is associated with a sustained antiviral activity in the TDF group, in which patients reached the threshold of HBV undetectability at a faster rate and in a larger proportion than those taking ADV.