Asian-Pacific consensus statement on the management of chronic hepatitis B: a 2008 update

The role of quantitative hepatitis B serology in the natural history and management of chronic hepatitis B

Chronic hepatitis B (CHB) remains a serious clinical problem worldwide. Advances in molecular technology have enabled the development of sensitive assays for the detection and quantification of hepatitis B virus (HBV) nucleic acid and demonstrated a positive correlation between serum HBV DNA levels and disease progression. Assessment of specific serologic and virologic factors also plays a pivotal role in the diagnosis and effective management of individuals with CHB. Recent development of quantitative assays for intrahepatic HBV replicative intermediates, as well as hepatitis B e antigen and hepatitis B surface antigen, has spurred investigation into the relationship between these factors and response to antiviral therapy and disease progression. Recent findings from preclinical and clinical investigations indicate that these factors may have promise in identifying patients likely to respond to treatment. Additional work is needed to standardize and validate these assays before they can be considered to be of true diagnostic value. Further evaluation is needed to decide which will have the greatest clinical applicability.

Prevention of hepatocellular carcinoma in hepatitis B virus infection

Chronic hepatitis B is the main risk factor for hepatocellular carcinoma (HCC) in Asia. The most important preventive strategy's adoption of the universal hepatitis B vaccination program is now in its third decade. There is a clear reduction in both chronic hepatitis B virus (HBV) infection (hepatitis B surface antigen "carriage") but also in childhood HCC in Taiwan. An outstanding concern is variability in vaccine coverage between countries. For patients with chronic hepatitis B, serum HBV DNA levels have emerged as the key risk factor for development of HCC. The initial treatment for chronic hepatitis B was interferon. One randomized control trial, and several case-control or cohort studies have shown benefits for preventing HCC, particularly in cirrhotic patients who responded to therapy. With nucleos(t)ide analogs, the most important study has been the Asian Cirrhosis Lamivudine multicenter randomized controlled trial. This showed that lamivudine can reduce disease progression in HBV-related cirrhosis, including an approximately 50% decrease in HCC incidence. Such efficacy was achieved despite emergence of drug resistance in approximately 50% of cases. Case-control studies have suggested that hepatitis B cases without cirrhosis may also benefit. In conclusion, it is now possible to prevent HBV-related HCC. The most effective method is hepatitis B vaccination, which prevents chronic HBV infection and chronic liver disease resulting therefrom. Interferon therapy appears to confer benefit but the evidence is weaker. First-generation oral antiviral (lamivudine) reduces HCC risk, particularly in cirrhotics. Long-term outcome data with newer, more potent HBV antivirals that have a higher genetic barrier to drug resistance are eagerly awaited.

Antiviral therapy of chronic hepatitis B: opportunities and challenges in Asia

Asia comprises more than 40 countries encompassing a wide geographic area with a very large population. Many of these countries have low-income economies together with high endemicity of chronic hepatitis B virus (HBV) infection, which is usually acquired perinatally or during early childhood. The well elucidated natural history of chronic HBV infection, together with the extensive research and the longest experience in the use of therapeutic agents in Asia have provided a great opportunity for Asian patients to benefit from recent advancements. However, treatment of chronic HBV infection is a complex task that requires individualized assessment, thus representing a great challenge for general physicians. The inherent problems of the drugs currently available, together with a lack of awareness of the disease among patients, government, and healthcare practitioners are obstacles to proper management of HBV. The most critical challenge and obstacle is the high cost of medical care and antiviral drugs. Lack of adequate reimbursement for treatment and diagnostic testing makes adherence to treatment guidelines impossible. Hence lamivudine is still widely used in Asia. To address these challenges, the ongoing awareness campaigns, active screening programs, educational activities are needed but must be enhanced. Cost-cutting measures and international support are essential to improve the difficult situation in this part of the world.

Chronic hepatitis B in Asian women of childbearing age

Hepatitis B virus (HBV) infection is a serious clinical problem affecting approximately 2 billion people worldwide. An estimated 350 million live with chronic hepatitis B (CHB) infection and are at an increased risk for serious liver sequelae and death from acute or chronic consequences of CHB infection. Individuals with CHB have a 20-30% risk of early death from complications, including liver cirrhosis and hepatocellular carcinoma. In the Asia-Pacific region, half of the CHB burden results from vertical or mother-to-child transmission, with early childhood horizontal transmission accounting for the remaining half. Screening and vaccination are key factors in the successful prevention and control of HBV infection. Over the last 20 years, the implementation of screening programs and universal HBV vaccination for all individuals born in endemic areas have reduced the prevalence of HBV infection and HBV-related liver diseases among individuals younger than 30 years. Women of childbearing age are key stakeholders in preventing HBV infection and, as such, play a critical role in reducing the vertical and horizontal transmission of HBV. Further efforts are needed to implement screening and educational programs for women of childbearing age, particularly those with CHB, to prevent the transmission of HBV to newborns, spouses, other household members, and sexual partners. In addition, healthcare workers need to learn how to avoid iatrogenic transmission in the healthcare setting. This article reviews these issues and highlights areas in which their engagement with public health efforts serves to improve quality of life and society as a whole.

Baseline characteristics and early on-treatment response predict the outcomes of 2 years of telbivudine treatment of chronic hepatitis B

BACKGROUND/AIMS

In the GLOBE trial, telbivudine treatment was identified as a significant, independent predictor of better outcomes at 2 years. We analyzed all telbivudine recipients in this trial to determine the predictors of optimal outcomes.

METHODS

The intent-to-treat population comprised 458 HBeAg-positive and 222 HBeAg-negative telbivudine-treated patients. Multivariate logistic regression analyses were employed to evaluate baseline and/or early on-treatment variables.

RESULTS

Baseline HBV DNA<9 log(10)copies/mL, or ALT levels > or = 2x above normal were strong pretreatment predictors for HBeAg-positive, but not for HBeAg-negative patients. However, non-detectable serum HBV DNA at treatment week 24 (TW24) was the strongest predictor for better outcomes for both groups. A combination of pretreatment characteristics plus TW24 response identified subgroups with the best outcomes: (1) HBeAg-positive patients with baseline HBV DNA<9 log(10)copies/mL, ALT > or = 2x above normal and non-detectable HBV DNA at TW24 achieved at 2 years: non-detectable HBV DNA in 89%, HBeAg seroconversion in 52%, telbivudine resistance in 1.8%; and (2) HBeAg-negative patients with baseline HBV DNA<7 log(10)copies/mL and non-detectable serum HBV DNA at TW24 achieved at 2 years: non-detectable HBV DNA in 91%, telbivudine resistance in 2.3%.

CONCLUSION

During telbivudine treatment, non-detectable serum HBV DNA at treatment week 24 is the strongest predictor for optimal outcomes at 2 years.

Severe acute exacerbation of chronic hepatitis B: a unique presentation of a common disease

Severe acute exacerbation is a unique presentation of chronic hepatitis B characterized by very high alanine aminotransferase level accompanied by jaundice and hepatic decompensation. The underlying pathogenesis is likely related to excessive immune clearance, which may be related to the genotype of hepatitis B virus. The mortality is very high once hepatic encephalopathy develops, but some patients can recover to almost normal liver function in contrast to patients with end-stage liver cirrhosis. This condition should be differentiated from acute hepatitis B and other causes of acute hepatitis must be excluded. Conventional prognostic systems may not be applicable to severe acute exacerbation of chronic hepatitis B. In general, patients who have thrombocytopenia, hyperbilirubinemia and coagulopathy have a higher risk of mortality regardless of the serum alanine aminotransferase levels. There is no evidence that lamivudine treatment can reduce the short-term mortality of severe acute exacerbation. However, patients with severe acute exacerbation tend to have a higher rate of maintained virological response, higher rate of hepatitis B e antigen seroconversion and low rate of drug resistance on extended lamivudine treatment as compared to other chronic hepatitis B patients. Virological relapse and severe hepatitis reactivation is common after treatment cessation and therefore long-term antiviral treatment is recommended. Liver transplantation, particularly living donor liver transplantation, should be considered for patients who develop hepatic failure secondary to severe acute exacerbation.

Patterns of managing chronic hepatitis B treatment-related drug resistance: a survey of physicians in Mainland China, South Korea, Taiwan, and Thailand

PURPOSE

The emergence of antiviral resistance can negate the benefits of antiviral therapy in patients with chronic hepatitis B (CHB). This study aimed to assess how physicians in Asia manage suspected antiviral resistance.

METHODS

Randomly selected CHB-treating physicians in Mainland China, South Korea, Taiwan, and Thailand underwent a face-to-face interview. A standardized questionnaire was used to assess how physicians identify, monitor, and manage suspected resistance and its associated medical costs.

RESULTS

We interviewed 575 physicians from January to May 2008. Most physicians preferred a "prevention-of-antiviral resistance" strategy over a "rescue-once-resistance-develops" strategy. Physicians had encountered lamivudine resistance most frequently (96-100% of respondents), followed by the resistance to adefovir (18-58%) and entecavir (3-7%). While physicians in South Korea and Taiwan have access to resistance testing, physicians in Mainland China and Thailand have limited access to resistance testing but rely on HBV DNA and alanine aminotransferase (ALT) tests to identify resistance. Once resistance is suspected, 60% of the physicians in Mainland China, South Korea, and Thailand monitored these patients quarterly and the remaining 40% opted for monthly follow-up. In comparison, 70% of the Taiwanese physicians monitored these patients monthly. The average total direct medical costs, excluding antiviral costs, to manage a patient during the first year after suspected resistance is identified ranged from USD $319 to USD $709.

CONCLUSIONS

Limited access to HBV resistance tests causes physicians in Asia to manage suspected resistance by various HBV DNA assays and ALT tests. This raises concerns that resistance may not be detected early enough to be rescued efficiently.

HBeAg seroconversion as an important end point in the treatment of chronic hepatitis B

During the natural history of chronic hepatitis B virus (HBV) infection, the loss of serum hepatitis B e antigen (HBeAg) and the development of anti-HBe antibodies (HBeAg seroconversion) mark a transition from the immune-active phase of disease to the inactive carrier state. This review examines the evidence from natural history and cohort studies on the relationship between HBeAg seroconversion and disease progression. The role of HBeAg seroconversion as an important milestone in the management of HBeAg-positive patients with chronic hepatitis B (CHB), as well as the advantages and disadvantages of administering a finite course of therapy for HBeAg-positive CHB, is also discussed. The evidence from natural history and cohort studies indicates that spontaneous or treatment-induced HBeAg seroconversion is associated with lower rates of disease progression to cirrhosis and hepatocellular carcinoma, a potential of hepatitis B surface antigen seroconversion, and improved survival rates. Updated guidelines developed by major liver associations recommend stopping oral therapy for HBeAg-positive patients who achieve sustained HBeAg seroconversion with polymerase chain reaction-undetectable HBV-DNA on two separate occasions for 6 or more months apart, taking into consideration the individual's clinical and virologic response to therapy, as well as the severity of liver disease. Thus, early induction of HBeAg seroconversion with interferon-based therapy or oral nucleos(t)ide analogues has important clinical and socioeconomic implications for the management of CHB.

Chronic hepatitis B: who to treat and which choice of treatment?

The goal of antiviral therapy in patients with chronic hepatitis B is to prevent, through persistent suppression of HBV replication, cirrhosis and hepatocellular carcinoma. Currently, seven drugs are available: IFN-alpha, pegylated interferon, lamivudine, adefovir dipivoxil, entecavir, telbivudine and tenofovir. The choice of the drugs should always take into consideration the clinical features of patients, the antiviral efficacy of each drug, the risk of developing resistance, the long-term safety profile, the method of administration and the cost of therapy. Ideal candidates for treatment are hepatitis B e antigen-positive patients with a prolonged phase of immune clearance and hepatitis B e antigen-negative patients with elevated levels of serum HBV DNA, abnormal alanine aminotransferase and histologic evidence of moderate or severe liver necroinflammation and/or fibrosis. Patients with compensated or decompensated cirrhosis should be treated, even if alanine aminotransferase levels are normal and/or serum HBV DNA levels are low, in order to prevent disease flare and to improve liver function.

Long-term outcome of hepatitis B e antigen-negative hepatitis B surface antigen carriers in relation to changes of alanine aminotransferase levels over time

The baseline alanine aminotransferase (ALT) level was reported to have prognostic value in chronic hepatitis B virus (HBV) infection, during which ALT may change over time. Instead of baseline ALT, this study aimed to study the prognostic value of the height of ALT during the course of chronic HBV infection. A total of 4376 asymptomatic hepatitis B e antigen (HBeAg) negative, surface antigen (HBsAg) carriers with baseline ALT less than 2 times the upper limit of normal (ULN) were monitored with ALT measurement and ultrasonography every 3 to 12 month for over 3 years. Maximal ALT levels during follow-up were correlated with long-term outcomes using morbidity and mortality data from hospital records, cancer registration, and national mortality database. Baseline ALT level was normal in 3673 subjects and increased to abnormal level in 1720 (46.8%) during a mean follow-up period of 13.4 +/- 5.2 (3.0-28.7) years. The incidence of liver cirrhosis, hepatocellular carcinoma (HCC), and mortality increased with increasing maximal ALT level during follow-up, especially in those with maximal ALT of at least 2 times ULN, as compared with those who maintained normal ALT. Cox regression analysis indicated that age at entry, sex, and maximal ALT level during follow-up were significant independent factors associated with the development of cirrhosis, HCC, and mortality whereas cirrhosis was also an independent factor for HCC development and mortality.

CONCLUSION

Persistently normal ALT was associated with excellent long-term prognosis, whereas increasing ALT levels of at least 2 times ULN during follow-up was associated with increasing morbidity and mortality. ALT of at least 2 times ULN is therefore an appropriate threshold for anti-HBV therapy, whereas those with ALT 1 to 2 times ULN require liver biopsy for decision.

Application of surveillance programs for hepatocellular carcinoma in the Asia-Pacific Region

Hepatocellular carcinoma (HCC) is a potential target for cancer surveillance (or screening) as it occurs in well-defined, at-risk populations and curative therapy is possible only for small tumors. Surveillance has been recommended by regional liver societies and is practiced widely, but its benefits are not clearly established. Hepatic ultrasonography with or without alpha fetoprotein (AFP) performed every 6 months is the preferred program. Surveillance of HCC has been well shown to detect small tumors for curative treatment, which may be translated to improved patient survival. However, most studies are limited by lead-time bias, length bias for early diagnosis of small HCC, different tumor growth rates and poor compliance with surveillance. Cost-effectiveness of surveillance programs depends on the rate of small HCC detected 'accidentally' (routine imaging) in a comparator group, annual incidence of HCC with various etiologies, patient age and the availability of liver transplantation. The incremental cost-effectiveness for 6-monthly AFP and ultrasound has been estimated from approximately $US 26,000-74,000/quality adjusted life years (QALY). All cirrhotic patients are therefore recommended for HCC surveillance unless the disease is too advanced for any curative treatment. As chronic hepatitis B can develop into HCC without going through liver cirrhosis, high-risk non-cirrhotic chronic hepatitis B patients are also recommended for HCC surveillance. In conclusion, HCC surveillance could be effective at reducing disease-specific mortality with acceptable cost-effectiveness among selected patient groups, provided it is a well-organized program.

Antiviral activity, dose-response relationship, and safety of entecavir following 24-week oral dosing in nucleoside-naive Japanese adult patients with chronic hepatitis B: a randomized, double-blind, phase II clinical trial

PURPOSE

A randomized, double-blind, multicenter study (ETV-047) was conducted to evaluate the dose-response relationship of entecavir and compare its antiviral activity and safety with lamivudine in Japanese patients with chronic hepatitis B (CHB).

METHODS

One hundred thirty-seven nucleoside-naive adult patients with CHB were randomized to once-daily oral doses of entecavir 0.01, 0.1, or 0.5 mg or lamivudine 100 mg for 24 weeks. The primary efficacy end point used to evaluate the dose-response relationship was mean change from baseline in serum hepatitis B virus (HBV) DNA level at week 22, as determined by polymerase chain reaction assay.

RESULTS

Entecavir demonstrated a clear dose-response relationship, with mean change from baseline in serum HBV DNA level of -3.11, -4.77, and -5.16 log(10) copies/ml with entecavir 0.01, 0.1, and 0.5 mg, respectively. Entecavir 0.5 mg was superior to lamivudine 100 mg for the mean change in HBV DNA level (-5.16 vs. -4.29 log(10) copies/ml; P = 0.007). The overall incidence of adverse events was comparable between treatment groups. Two patients discontinued treatment because of adverse events (one with liver cirrhosis [entecavir 0.5 mg] and one with grade 4 serum alanine aminotransferase (ALT) elevation, nausea, and malaise [lamivudine 100 mg]). Serum ALT flares were observed in four patients; flares were associated with 2 log(10) reductions or more in HBV DNA level and resolved without dose interruption.

CONCLUSION

Entecavir 0.01-0.5 mg is well tolerated and produces a dose-dependent reduction in viral load in nucleoside-naive Japanese patients with CHB. Compared with lamivudine 100 mg, entecavir 0.1 mg demonstrated noninferiority and entecavir 0.5 mg was superior in this population.

A 7-year study of lamivudine therapy for hepatitis B virus e antigen-positive chronic hepatitis B patients in China

OBJECTIVE

To evaluate the long-term efficacy and safety of lamivudine treatment for chronic hepatitis B and the impact of emergence of YMDD mutation of hepatitis B virus (HBV).

METHODS

A total of 429 patients with serum HBsAg, HBeAg and HBV DNA positive were randomized to receive either lamivudine 100 mg daily or a placebo in a 3:1 ratio for the first 12 weeks. Thereafter, all patients were administered with lamivudine 100 mg/d for 5 years and followed up for 2 years.

RESULTS

After 12 weeks of the lamivudine treatment, serum HBV DNA levels decreased rapidly and HBV DNA negativity (<1.6 pg/mL) was 92.2%, whereas it was only 14.1% (P < 0.01) in the placebo group. At the end of 5 years, serum HBV DNA continued to be substantially suppressed. The loss of HBeAg and seroconversion were significantly correlated with baseline alanine aminotransferase (ALT) levels, in patients with baseline ALT > 2 x upper limits of normal, the loss of HBeAg was 54% and seroconversion rate was 50%, respectively. YMDD mutation developed in 70.8% of the patients at years 5. In YMDD mutant patients, HBV DNA levels were increased moderately and with mild to moderate elevations of ALT. ALT flares (ALT > 5ULN) occurred in 22 patients, 16 with YMDD variants and six with non-variants. One year durability of seroconversion after stopping lamivudine was 80%.

CONCLUSION

Lamivudine is effective and tolerable for chronic hepatitis B.

A review of the natural history of chronic hepatitis B in the era of transient elastography

Understanding the natural history of chronic hepatitis B is important in order to predict the prognosis, to stratify the risk of hepatocellular carcinoma and to select appropriate candidates for antiviral treatment. Liver fibrosis is the pathogenic process that leads to liver cirrhosis. The study of liver fibrosis in the past has largely been hampered by the invasive nature of a liver biopsy. Most liver biopsy series represent biased populations with more active disease. Transient elastography is a reliable and non-invasive measurement of liver fibrosis that allows the study of liver fibrosis among patients without clinical indication for liver biopsy. Large studies using transient elastography in patients with predominantly normal alanine aminotransferase levels have been reported recently. The different roles of patient age, hepatitis B virus DNA and alanine aminotransferase levels in the risk stratification for advanced liver fibrosis have been defined in hepatitis B e antigen-positive and hepatitis B e antigen-negative chronic hepatitis B patients. The relationship between metabolic syndrome and chronic hepatitis B is also explored. In this review, new insights from studies using transient elastography on the natural history of chronic hepatitis B with special focus on liver fibrosis will be summarized and discussed.

Evaluation of impact of serial hepatitis B virus DNA levels on development of hepatocellular carcinoma

We aimed to investigate the impact of hepatitis B virus (HBV) DNA on the development of hepatocellular carcinoma (HCC). We conducted a case/control study based on 506 chronic HBV patients followed up since 1997. Forty-one patients developed HCC, and each of them was age and gender matched with two simultaneously recruited controls without HCC. HBV DNA was measured at the initial visit, at yearly intervals, and at the last visit. Patient age at the time of HCC development was 55 +/- 9 years. Forty-nine (40%) patients experienced antiviral treatment. The median time from diagnosis to the development of HCC was 17 months, and the control patients were followed for 92 months. At the trough level (defined as lowest level among all studied visits), more (27 patients; 66%) HCC patients had HBV DNA levels of >10,000 copies/ml than the controls (17 patients; 21%). The area under the receiver operating characteristic curve of the trough log HBV DNA level for HCC was 0.79 (95% confidence interval [CI], 0.69 to 0.89). Trough log HBV DNA (odds ratio, 11.4; 95% CI, 3.6 to 37.6; P < 0.0001) and liver cirrhosis (odds ratio, 11.4; 95% CI, 3.6 to 36.2; P < 0.0001) levels were independently associated with HCC after an adjustment for age, gender, antiviral treatment, and HBV genotype. The difference in the trough HBV DNA level was more obvious among untreated patients (5.7 +/- 1.4 log copies/ml in HCC patients versus 3.2 +/- 1.3 log copies/ml in control patients; P < 0.0001) than among those who had received antiviral treatment (3.0 +/- 1.4 log copies/ml in HCC patients versus 2.5 +/- 0.9 log copies/ml in control patients; P = 0.38). A high trough HBV DNA level was associated with a higher risk of HCC. Whether antiviral treatment could prevent HCC was uncertain.

Spontaneous increases in alanine aminotransferase levels in asymptomatic chronic hepatitis B virus-infected patients

BACKGROUND & AIMS

No information is available about the frequency or factors that predict spontaneous increases in alanine aminotransferase (ALT) levels in asymptomatic Indian patients with chronic hepatitis B virus (HBV) infection who are HB e antigen (HBeAg) negative and have normal ALT levels.

METHODS

We followed 217 asymptomatic patients with chronic HBV who were HBeAg negative, anti-HBe antigen (anti-HBe) positive, and had normal ALT levels. Spontaneous increases in ALT levels (ALT flares) were considered to be >2-fold the upper limit of normal (ULN) and were accompanied by HBV DNA levels>or=10(5) copies/mL or a 100-fold increase from the previously measured level.

RESULTS

During a median follow-up period of 69.0 months, spontaneous ALT flares occurred in 43 patients (an annual rate of 4.3%), with cumulative probabilities of 10.8% and 47.3% after 5 and 10 years, respectively. Based on multinomial logistic regression, the probability of an ALT flare correlated with age>or=30 years at presentation (odds ratio [OR], 5.31; 95% confidence interval [CI]: 1.53-18.39; P=.008), male sex (OR, 4.54; 95% CI: 1.01-20.76; P=.05), and presence of a precore mutation (OR, 10.99; 95% CI: 3.67-32.92; P<.001). The median time to spontaneous ALT flare after enrollment was 25 months (range, 1-128 months; 10th percentile=3.4 months).

CONCLUSIONS

In asymptomatic patients with chronic HBV infection who have normal ALT levels and are HBeAg negative, the annual rate of ALT flares was 4.3%. Precore mutants, male sex, and age>or=30 years at presentation are independent predictors for an ALT flare. A follow-up every 3 months can capture up to 90% of flares and would help identify patients who require antiviral therapy.

Hepatitis B virus infection

Since the introduction of the hepatitis B vaccine and other preventive measures, the worldwide prevalence of hepatitis B infection has fallen. However, chronic infection remains a challenging global health problem, with more than 350 million people chronically infected and at risk of hepatic decompensation, cirrhosis, and hepatocellular carcinoma. An improved understanding of hepatitis B virology, immunology, and the natural course of chronic infection, has identified hepatitis B virus replication as the key driver of immune-mediated liver injury and disease progression. The approval of potent oral antiviral agents has revolutionised hepatitis B treatment since 1998. Conventional and pegylated interferon alfa and nucleoside and nucleotide analogues are widely authorised treatments, and monotherapy with these drugs greatly suppresses virus replication, reduces hepatitis activity, and halts disease progression. However, hepatitis B virus is rarely eliminated, and drug resistance is a major drawback during long term therapy. The development of new drugs and strategies is needed to improve treatment outcomes.

2-Year GLOBE trial results: telbivudine Is superior to lamivudine in patients with chronic hepatitis B

BACKGROUND & AIMS

The GLOBE trial has compared the efficacy and safety of telbivudine versus lamivudine treatment over 2 years in patients with chronic hepatitis B.

METHODS

Hepatitis B e antigen (HBeAg)-positive (n = 921) and HBeAg-negative (n = 446) patients received telbivudine or lamivudine once daily for 104 weeks. The primary outcome, assessed in the intent-to-treat population, was therapeutic response (hepatitis B virus DNA <5 log(10) copies/mL and either HBeAg loss or normalization of alanine aminotransferase [ALT] level).

RESULTS

The therapeutic response to telbivudine was superior to that of lamivudine in HBeAg-positive (63% vs 48%; P < .001) and HBeAg-negative (78% vs 66%; P = .007) patients. HBeAg-positive patients given telbivudine also had better outcomes compared with lamivudine in terms of nondetectable viremia (< 300 copies/mL) at 55.6% versus 38.5% (P < .001), HBeAg loss at 35.2% versus 29.2% (P = .056), and viral resistance at 25.1% versus 39.5% (P < .001). Hepatitis B e antigen seroconversion was 29.6% versus 24.7% (P = .095) in all patients and 36% versus 27% (P = .022) in patients with baseline ALT level > or = 2 times normal. Telbivudine-treated HBeAg-negative patients showed higher rates of nondetectable viremia compared with lamivudine at 82.0% versus 56.7% (P < .001) and less resistance at 10.8% versus 25.9% (P < .001). Adverse events occurred with similar frequency, whereas grade 3/4 increases in creatine kinase levels were more common in patients given telbivudine (12.9% vs 4.1%, P < .001). Multivariate logistic regression analyses identified telbivudine treatment, among other variables, as an independent predictor of better week 104 outcomes.

CONCLUSIONS

Telbivudine is superior to lamivudine in treating patients with chronic hepatitis B over a 2-year period.

On-Treatment Outcome Prediction and Adjustment during Chronic Hepatitis B Therapy: Now and Future

Studies published to date regarding on-treatment outcome prediction during chronic hepatitis B therapy were reviewed. Studies have shown that initial virological responses in terms of week 24 serum hepatitis B virus (HBV) DNA levels are associated with therapeutic outcomes of 1-year pegylated interferon-α and entecavir therapy, and weeks 52 or 104 of lamivudine and telbuvudine therapy. HBV DNA levels at week 48 are also associated with long-term adefovir therapy outcomes. Conceptual on-treatment adjustment and strategies have been proposed; however, this approach seems only necessary during therapy with nucleos(t)ide analogues with substantial risk of drug resistance. In addition, studies are needed to decide whether switching to or adding on a second drug, and with which drug, is the most cost-effective strategy.

HBeAg-positive chronic hepatitis B: why do I treat my patients with pegylated interferon

Worldwide, chronic hepatitis B virus infection is a major cause of end-stage liver disease and hepatocellular carcinoma. While the past two decades have brought major advances in the availability of treatments to help delay or prevent these outcomes, treatment of chronic hepatitis B remains a serious challenge. With the recent availability of potent new nucleot(s)ide such as entecavir, tenofovir and telbuvidine, I still use pegylated interferon (PEG-IFN)-alpha for the treatment of chronic HBeAg-positive patients. This is based on its relatively higher effectiveness in restoring the host immune control on viral replication, resulting in sustained diseases remission in a proportion of patients, a finite course of therapy and the absence of viral resistance. The two major hindrances to its wide application are its lack of effectiveness in a large proportion of patients and its side-effect profile. The former shortcoming can be circumvented to a certain extent with the use of response predictor models. Recently, based on long-term follow-up study, the better durability of sustained response further enhances the confidence in the use of PEG-IFN-alpha in chronic HBeAg-positive patients.

Nucleos(t)ide analogues for hepatitis B virus: strategies for long-term success

Studies in the past decades have shown that active hepatitis B virus (HBV) replication is the key driver of liver injury and disease progression, and thus sustained viral suppression is of paramount importance in the management of chronic HBV infection. The nucleos(t)ide analogues lamivudine, adefovir, entecavir, telbivudine and tenofovir are potent inhibitors of HBV polymerase/reverse transcriptase activity and are highly effective in the suppression of HBV replication, but rarely eliminate the virus. Long-term therapy is usually required to achieve sustained hepatitis B e antigen seroconversion, HBV DNA suppression, ALT normalization and fibrosis reversal. Maintained long-term therapy has been demonstrated to significantly lower the rate of hepatic decompensation and development of cirrhosis or hepatocellular carcinoma. However, drug resistance is a serious risk on prolonged nucleos(t)ide analogue therapy, and this poses a critical challenge. Prevention and proper management of drug resistance are crucial to ensure long-term success.

Peginterferon for the treatment of chronic hepatitis B in the era of nucleos(t)ide analogues

The practising clinician is currently faced with a number of effective treatment options for chronic hepatitis B, including two formulations of interferon (standard IFN and pegylated IFN) and five nucleos(t)ide analogues (lamivudine, adefovir, entecavir, telbivudine and tenofovir). Treatment strategies can be divided into those aiming for sustained response after discontinuation of therapy and those that need to be maintained by prolonged antiviral therapy. Sustained response is particularly achieved with interferon-based therapy, while treatment-maintained response can be achieved with long-term nucleos(t)ide analogue therapy in the majority of patients. Of currently available drugs for the treatment of chronic hepatitis B, PEG-IFN seems to result in the highest rate of off-treatment sustained response after a 1-year course of therapy. Sustained transition to the immune-control phase (inactive HBsAg carrier state) can be achieved in 30-35% of HBeAg-positive patients and 20-25% of HBeAg-negative patients. Loss of HBsAg has been observed in 11% of both HBeAg-positive and HBeAg-negative patients after 3-4 years. Since hepatitis B virus (HBV) genotype is an important predictor of response to PEG-IFN, determination of HBV genotype is essential in patients in whom sustained off-treatment response is pursued. Aiming for sustained response is of particular interest because many HBV-infected patients are in need of antiviral therapy at a young age and may otherwise require indefinite antiviral therapy.

A review of the one-year incidence of resistance to lamivudine in the treatment of chronic hepatitis B : Lamivudine resistance

PURPOSE

The development of antiviral resistance is a recognized challenge to successful treatment of chronic hepatitis B (CHB), but it has been difficult to establish an accurate estimate of its incidence due to a number of factors: (a) lack of an accepted definition of antiviral resistance; (b) lack of a standardized assay to assess resistance; and (c) lack of consensus on patient selection criteria for resistance testing. Lamivudine, an effective and well-established antiviral agent, has been reported to show one-year resistance rates in CHB ranging from 6% to 32%, but methodologies used to calculate these rates vary considerably. This article reviews the clinical, statistical, and laboratory methodologies of clinical studies reporting one-year rates of antiviral resistance to lamivudine in CHB.

METHODS

Studies reporting one-year resistance rates to lamivudine in CHB were analyzed for methodologic differences and their influence on reported resistance rates.

RESULTS

Studies using only a genotypic definition of resistance reported one-year rates ranging from 14% to 32%. Studies assessing genotypic resistance in patients with evidence of virologic breakthrough reported much lower one-year resistance rates of 6.4-15.4%.

CONCLUSIONS

It is important when comparing resistance rates to antiviral drugs in CHB to consider the methodology and definition of resistance used because this can dramatically influence the results.

A review of the one-year incidence of resistance to lamivudine in the treatment of chronic hepatitis B : Lamivudine resistance

PURPOSE

The development of antiviral resistance is a recognized challenge to successful treatment of chronic hepatitis B (CHB), but it has been difficult to establish an accurate estimate of its incidence due to a number of factors: (a) lack of an accepted definition of antiviral resistance; (b) lack of a standardized assay to assess resistance; and (c) lack of consensus on patient selection criteria for resistance testing. Lamivudine, an effective and well-established antiviral agent, has been reported to show one-year resistance rates in CHB ranging from 6% to 32%, but methodologies used to calculate these rates vary considerably. This article reviews the clinical, statistical, and laboratory methodologies of clinical studies reporting one-year rates of antiviral resistance to lamivudine in CHB.

METHODS

Studies reporting one-year resistance rates to lamivudine in CHB were analyzed for methodologic differences and their influence on reported resistance rates.

RESULTS

Studies using only a genotypic definition of resistance reported one-year rates ranging from 14% to 32%. Studies assessing genotypic resistance in patients with evidence of virologic breakthrough reported much lower one-year resistance rates of 6.4-15.4%.

CONCLUSIONS

It is important when comparing resistance rates to antiviral drugs in CHB to consider the methodology and definition of resistance used because this can dramatically influence the results.

The Roadmap concept: using early on-treatment virologic responses to optimize long-term outcomes for patients with chronic hepatitis B

Several large observational, longitudinal studies of the natural history of chronic hepatitis B (CHB) have demonstrated that high levels of hepatitis B virus (HBV) replication are associated with long-term risk of cirrhosis, decompensation, hepatocellular carcinoma, and liver-related mortality. The corollary is also true—profound and sustained suppression either spontaneously or during antiviral therapy will prevent disease progression and complications. Multiple analyses of various baseline factors and on-treatment responses have identified the absolute HBV DNA level after 24 weeks of therapy as the best predictor of long-term efficacy. Lower 24-week serum HBV DNA levels after lamivudine, telbivudine, or entecavir are associated with higher rates of maintained HBV DNA nondetectability, ALT normalization, HBeAg seroconversion, and lack of resistance. Patients with undetectable serum HBV DNA levels after 24 weeks have the best long-term outcomes while those with levels remaining above 10,000 copies per ml are unlikely to benefit from long-term therapy with that particular agent and either the addition or switch to another antiviral agent with increased potency but without cross resistance could be considered at this time point. In the future, improved on-treatment monitoring should facilitate treatment strategies to optimize long-term outcomes among patients receiving oral antiviral therapy for CHB.

Hepatitis B virus reactivation in breast cancer patients receiving cytotoxic chemotherapy: a prospective study

Breast cancer is a rapidly increasing problem in many developing countries, and cytotoxic chemotherapy is now an integral part of its management. In several developing countries, the carriage of hepatitis B virus (HBV) in cancer patients may be as high as 12%, and such patients are at risk of developing fatal HBV reactivation during chemotherapy. HBV reactivation is well recognized in patients with hematological malignancies, but limited data are available on patients with other, more common, cancers, such as breast cancer. Recent data have suggested that increased viral replication, an indication of HBV reactivation, may precede clinical hepatitis. In the absence of serial HBV DNA monitoring, HBV reactivation during chemotherapy may have been underestimated. In this prospective study, breast cancer patients who were hepatitis B surface antigen (HBsAg) seropositive were followed up during chemotherapy. The main objectives were to determine the incidence of HBV reactivation in breast cancer patients undergoing conventional chemotherapy; to investigate whether "serial HBV DNA monitoring" improves the accuracy of diagnosing HBV reactivation when compared with previous schema that only measured HBV DNA at the time of clinical hepatitis ("conventional monitoring"); and to assess the clinical consequences as a result of developing the condition. The secondary objective was to identify risk factors associated with this condition. Over an 18-month period, 41 patients were studied. Ten developed HBV reactivation by conventional monitoring criteria, but with serial HBV DNA monitoring, seven additional patients were diagnosed when increased HBV DNA levels were detected before, but not concomitant with, clinical hepatitis. Thus, a total of 17 patients (41%) developed HBV reactivation. Premature termination of chemotherapy or delay in treatment schedules occurred in 71% of the patients who developed viral reactivation, as compared with 33% in those who did not develop the condition (P = 0.019). No risk factors associated with the development of HBV reactivation could be identified. Serial monitoring of HBV DNA, in addition to liver function, increases the sensitivity of diagnosing of HBV reactivation, and helps explain some cases that would otherwise be labeled as "cryptogenic hepatitis," for which concomitant HBV DNA measured at the time of hepatitis was undetectable. The present study highlights the importance of monitoring HBsAg-seropositive patients who are receiving chemotherapy for common solid tumors such as breast cancer.