Response to tenofovir monotherapy in chronic hepatitis B patients with prior suboptimal response to entecavir

Real-world safety and effectiveness of tenofovir alafenamide for 144 weeks in Japanese patients with chronic hepatitis B

Tenofovir alafenamide (TAF), a prodrug of tenofovir, delivers high levels of active drug to hepatocytes and is given in a lower dose than tenofovir disoproxil fumarate (TDF). TAF reduces viral replication in patients with chronic hepatitis B (CHB) similar to TDF and has shown a lower risk of the renal and bone toxicities associated with TDF use. This post-marketing surveillance study examined the safety and effectiveness of TAF in treatment-naïve and -experienced CHB patients who received TAF for 144 weeks at real-world clinical sites in Japan. Safety assessments included the incidence of adverse drug reactions (ADRs), renal and bone events, and changes in selected laboratory parameters. Effectiveness was based on the proportion of patients with HBV DNA levels below the lower limit of quantitation or <29 IU/mL. This analysis included 580 patients; 18.4% of whom were treatment-naïve. The cumulative incidence of ADRs was 0.21 per 100 person-months, and the incidence of serious ADRs was 0.01 (95% CI, 0.00-0.04) per 100 person-months. There were no ADRs of declines in estimated glomerular filtration rates, renal failure or proximal tubulopathy. The most common ADR was hypophosphataemia in seven (1.2%) patients. Two (0.4%) patients each had decreased blood phosphorus, bone mineral density decreased, dizziness and alopecia. Overall, the proportion of virologically suppressed patients increased from 68.8% at baseline to 97.5% at Week 144. These results confirm the real-world safety and effectiveness of TAF in Japanese patients with CHB and are consistent with the findings of other evaluations of the safety and efficacy of TAF in CHB.

Review article: switching patients with chronic hepatitis B to tenofovir alafenamide-a review of current data

BACKGROUND

The nucleos(t)ide analogues (NAs) entecavir (ETV), tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) are preferred treatment options for patients with chronic hepatitis B infection (CHB). However, resistance to ETV has been reported, especially with prior exposure to other NAs, and long-term TDF treatment has been associated with decline in renal function and loss of bone mineral density in some patients. Consequently, TAF may be preferable to ETV, TDF or other NAs in specific circumstances such as in patients with risk of bone or renal complications, elderly patients or those with previous NA experience.

AIM

To provide a summary of the available efficacy and safety data following switch to TAF from other NAs in patients with CHB in clinical studies and real-world settings.

METHODS

Literature searches were performed on PubMed and abstracts from three major international liver congresses between 2019 and 2021. Studies that included efficacy and/or safety data for patients with CHB switching from any NA to TAF were selected.

RESULTS

Thirty-six papers and abstracts were included in this narrative review. Switching from TDF to TAF maintained or improved virological and biochemical responses with improved bone and renal safety. Switching from ETV or other NAs to TAF maintained or improved virological and biochemical responses and varying results for bone and renal safety.

CONCLUSIONS

Switching to TAF appears to maintain or improve virological, biochemical and bone- and renal-related safety outcomes. These data support the concept of switching to TAF in some patients with CHB based on their individual circumstances.

Validation of risk prediction scores for hepatocellular carcinoma in patients with chronic hepatitis B treated with entecavir or tenofovir

Several prediction scores for the early detection of hepatocellular carcinoma (HCC) are available. We validated the predictive accuracy of age, albumin, sex, liver cirrhosis (AASL), RESCUE-B, PAGE-B and modified PAGE-B (mPAGE-B) scores in chronic hepatitis B (CHB) patients treated with entecavir (ETV) or tenofovir disoproxil fumarate (TDF). Between 2007 and 2014, 3171 patients were recruited (1645, ETV; 1517, TDF). The predictive accuracy of each prediction score was assessed. The mean age of the study population (1977 men; 1194 women) was 48.8 years. Liver cirrhosis was present in 1040 (32.8%) patients. During follow-up (median, 58.2 months), 280 (8.8%) patients developed HCC; these patients were significantly older; more likely to be male; had significantly higher proportions of liver cirrhosis, hypertension and diabetes; and had significantly higher values for the four risk scores than those who did not develop HCC (all P < .05). Older age (hazard ratio [HR] = 1.048), male sex (HR = 2.142), liver cirrhosis (HR = 3.144) and prolonged prothrombin time (HR = 2.589) were independently associated with an increased risk of HCC (all P < .05), whereas a higher platelet count (HR = 0.996) was independently associated with a decreased risk of HCC (P < .05). The predictive accuracy of AASL score was the highest for 3- and 5-year HCC predictions (areas under the curve [AUCs] = 0.818 and 0.816, respectively), followed by RESCUE-B, PAGE-B and mPAGE-B scores (AUC = 0.780-0.815 and 0.769-0.814, respectively). In conclusion, four HCC prediction scores were assessed in Korean CHB patients treated with ETV or TDF. The AASL score showed the highest predictive accuracy.

Taiwan consensus statement on the management of chronic hepatitis B

The experts of Taiwan Association for the Study of Liver (TASL) have actively participated and led the guidelines on hepatitis B virus (HBV) management by Asian Pacific Association for the Study of Liver (APASL) which is the first international association for the study of liver to publish the statement on HBV management before. However, there are more and more new data on the natural history and treatment of HBV infection in the past decade. These include new application of an old biomarker (quantitative HBsAg), clinical significance of HBV genotype and naturally occurring mutations, the role of non-invasive examination in evaluating severity of hepatic fibrosis, clinical significance of outcome calculators, new drug or new combination strategies towards more effective therapy and organ transplantation including liver and non-liver transplantation. It is time to publish the guidelines on HBV management of Taiwan. Hence, TASL have conducted an expert meeting to review, to discuss and to debate the relevant literatures, followed by draft the manuscript of HBV management guidelines and recommendations. The guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patient receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included.

Switching to tenofovir vs continuing entecavir for hepatitis B virus with partial virologic response to entecavir: a randomized controlled trial

Entecavir 0.5 mg (ETV) is widely used among treatment-naïve chronic hepatitis B (CHB) patients. However, 10%-30% of patients show partial virologic response (PVR) to the drug. If the hepatitis B virus (HBV) continues to replicate, the underlying liver disease may progress. Herein, we compared the efficacy of switching to tenofovir disoproxil fumarate (TDF) with that of continuing ETV in CHB patients with PVR to ETV. This was an open-label randomized controlled trial including CHB patients who had been receiving 0.5 mg of ETV for >12 months, but who still had detectable HBV DNA levels of >60 IU/mL without known resistance to ETV. Sixty patients were enrolled and 45 qualified for the study: Twenty-two patients were randomly assigned into the TDF group and 23 into the ETV group. After 12 months of treatment, the virologic response rate (HBV DNA <20 IU/mL) was significantly higher in the TDF group than in the ETV group, as measured using per-protocol analysis (55% vs 20%; P = .022) and intention-to-treat analysis (50% vs 17.4%; P = .020). The reduction in HBV DNA was greater (-1.13 vs -0.67 log₁₀ IU/mL; P = .024), and the mean HBV DNA level was lower (1.54 vs 2.01 log₁₀ IU/mL; P = .011) in the TDF group than in the ETV group. In conclusion, to achieve optimal response in CHB patients with PVR to ETV, switching to TDF would be a better strategy than continuing ETV. Appropriate modification of therapy would further improve the outcome of chronic HBV infection.

Real World Experience of Telbivudine Versus Entecavir in Patients with Chronic Hepatitis B, Including Long-Term Outcomes after Treatment Modification

PURPOSE

To estimate long-term outcomes after treatment modification in patients with chronic hepatitis B (CHB) treated with entecavir (ETV) and telbivudine (LdT).

MATERIALS AND METHODS

The study enrolled 131 nucleos(t)ide analogue (NA)-naïve CHB patients treated with ETV or LdT. During the 3-year study, NA treatment history including the incidence, the type of treatment modification, reasons for the modification, and overall complete virologic response (CVR) rate were retrospectively evaluated using the patients' medical records.

RESULTS

Among the 131 patients, 84 and 47 were initially treated with ETV and LdT, respectively. During the course of 3-year study, 82 patients in the ETV group (97.6%) maintained initial treatment whereas only 19 in the LdT group (40.4%). In the LdT group, 26 patients (92.9%) switched to another NA and another NA was added in 2 (7.1%) patients. An assessment of the CVR rate at 3 years, including treatment modification, showed that 89.3% and 95.7% of patients in the ETV and LdT groups, respectively, had undetectable serum hepatitis B virus DNA levels (p=0.329). Among LdT patients with treatment modification, the cumulative incidence rate of a CVR for rescue therapy was significantly higher in the tenofovir than in the ETV group (p=0.009).

CONCLUSION

During the 3-year study, there were no significant differences in the CVR between the ETV and LdT groups if appropriate rescue therapy was considered.

An expert consensus for the management of chronic hepatitis B in Asian Americans

BACKGROUND

Hepatitis B virus (HBV) infection is common with major clinical consequences. In Asian Americans, the HBsAg carrier rate ranges from 2% to 16% which approximates the rates from their countries of origin. Similarly, HBV is the most important cause of cirrhosis, hepatocellular carcinoma (HCC) and liver related deaths in HBsAg positive Asians worldwide.

AIM

To generate recommendations for the management of Asian Americans infected with HBV.

METHODS

These guidelines are based on relevant data derived from medical reports on HBV from Asian countries as well as from studies in the HBsAg positive Asian Americans. The guidelines herein differ from other recommendations in the treatment of both HBeAg positive and negative chronic hepatitis B (CHB), in the approach to HCC surveillance, and in the management of HBV in pregnant women.

RESULTS

Asian American patients, HBeAg positive or negative, with HBV DNA levels >2000 IU/mL (>10⁴ copies/mL) and ALT values above normal are candidates for anti-viral therapy. HBeAg negative patients with HBV DNA >2000 IU/mL and normal ALT levels but who have either serum albumin <3.5 g/dL or platelet count <130 000 mm³ , basal core promoter (BCP) mutations, or who have first-degree relatives with HCC should be offered treatment. Patients with cirrhosis and detectable HBV DNA must receive life-long anti-viral therapy. Indications for treatment include pregnant women with high viraemia, coinfected patients, and those requiring immunosuppressive therapy. In HBsAg positive patients with risk factors, life-long surveillance for HCC with alpha-fetoprotein (AFP) testing and abdominal ultrasound examination at 6-month intervals is required. In CHB patients receiving HCC treatments, repeat imaging with contrast CT scan or MRI at 3-month intervals is strongly recommended. These guidelines have been assigned to a Class (reflecting benefit vs. risk) and a Level (assessing strength or certainty) of evidence.

CONCLUSIONS

Application of the recommendations made based on a review of the relevant literature and the opinion of a panel of Asian American physicians with expertise in HBV treatment will inform physicians and improve patient outcomes.

Comparison of the Efficacy of Tenofovir Versus Tenofovir plus Entecavir in the Treatment of Chronic Hepatitis B in Patients With Poor Efficacy of Entecavir: A Systematic Review and Meta-analysis

PURPOSE

This study aimed to compare the efficacy between tenofovir disoproxil fumarate (TDF) and TDF plus entecavir (ETV) combination therapy in patients with chronic hepatitis B (CHB) with a poor response to ETV.

METHODS

We searched the China National Knowledge Infrastructure (CNKI), PubMed, EMBASE, and SCOPE libraries for articles using the keywords chronic hepatitis B virus or CHB or HBV, entecavir or ETV, and tenofovir or TDF.

FINDINGS

Five studies (from CNKI and PubMed) with a total of 408 patients met the inclusion criteria: 212 patients in the TDF group and 196 patients in the TDF plus ETV group. The rates of viral suppression between the 2 groups were comparable at weeks 24 and 48 of treatment (P = 0.546 vs P = 0.818). In addition, the subanalysis revealed that no significant differences were observed in the rates of viral suppression between the 2 groups at week 24 (subgroup 1 [partial response to ETV]: P = 0.822; subgroup 2 [resistance to ETV]: P = 0.294) and week 48 (subgroup 1: P = 0.797; subgroup 2: P = 0.545). No significant differences were found in alanine aminotransferase normalization, hepatitis B e antigen loss, hepatitis B e antigen seroconversion, virologic breakthrough, and tolerability between the 2 groups at weeks 24 and 48. Therefore, the results suggest that TDF monotherapy should be chosen for patients with CHB with a poor response to ETV for reasons of economy and convenience.

IMPLICATIONS

We conclude that TDF monotherapy is comparable to TDF-ETV combination therapy for patients with a poor response to ETV; thus, TDF monotherapy may be a better choice for these patients. However, because of the limited citations in this meta-analysis, complete and systematic evidence is needed to evaluate the differences in efficacy and tolerability between TDF and TDF-ETV. Larger and longer randomized clinical trials and further studies should be conducted to verify the results.

Low-level viremia and the increased risk of hepatocellular carcinoma in patients receiving entecavir treatment

The long-term clinical impact of low-level viremia (LLV; <2,000 IU/mL) is not well understood. As a result, it is unclear whether the development of LLV during entecavir monotherapy requires a change in therapy. A retrospective cohort of 875 treatment-naive chronic hepatitis B virus (HBV) monoinfected patients (mean age 47.7 years, male = 564 [65.5%], cirrhosis = 443 [50.6%]) who received entecavir monotherapy were analyzed for the development of hepatocellular carcinoma (HCC). The HCC risk was compared between patients who maintained virological response (MVR), defined by persistently undetectable HBV DNA (<12 IU/mL), and patients who experienced LLV, defined by either persistent or intermittent episodes of <2,000 IU/mL detectable HBV DNA. During a median 4.5 years of follow-up (range 1.0-8.7 years), HCC was diagnosed in 85 patients (9.7%). HCC developed more frequently in patients who experienced LLV than MVR (14.3% versus 7.5% at 5 years, P = 0.015). The hazard ratio comparing those with LLV to MVR was 1.98 (95% confidence interval = 1.28-3.06, P = 0.002, adjusted for age, sex, hepatitis B e antigen, baseline HBV DNA levels, and cirrhosis). Among patients with cirrhosis, those with LLV exhibited a significantly higher HCC risk than those with MVR (HCC incidence rate at 5 years 23.4% versus 10.3%, adjusted hazard ratio = 2.20, 95% confidence interval 1.34-3.60; P = 0.002). However, for patients without cirrhosis, there was no significant difference in the HCC risk between LLV and MVR.

CONCLUSION

LLV observed during entecavir monotherapy was associated with a higher risk of HCC, especially for those with cirrhosis, indicating that LLV during potent antiviral therapy is consequential. (Hepatology 2017;66:335-343).

TDF Monotherapy Is Effective Regardless of Prior Nucleos(t)ide Analogue Treatment in Chronic Hepatitis B Patients in China

Background/Aims

Many patients had to transfer to tenofovir disoproxil fumarate (TDF) if there is other nucleos(t)ide analogue (NA) resistance. We aimed to investigate antiviral effects of TDF monotherapy between NA-naive and NA-experienced chronic hepatitis B (CHB) patients in China.

Methods

A total of 102 NA-naive and NA-experienced CHB patients with TDF monotherapy (300 mg/day) were retrospectively analyzed for useful parameters up to 72 weeks.

Results

There were 36 and 66 patients with matched HBV DNA baseline level in NA-naïve and NA-experienced group, respectively. There were no significant differences between NA-naïve and NA-experienced groups in HBV DNA levels (all P > 0.05) and HBV DNA undetectable rates (all P > 0.05) at all time points. At the end of follow-up, HBV DNA undetectable rates in NA-naïve and NA-experienced group were 96.2% (25/26) and 91.8% (45/49), respectively (P = 0.476). Baseline HBV DNA level was the only independent predictor for HBV DNA negative time (P = 0.018). In addition, 27.8% (5/18) and 11.4% (4/35) achieved HBeAg seroconversion at the end of the follow-up, respectively (P = 0.133).

Conclusions

TDF monotherapy was effective regardless of prior NA experienced. Baseline HBV DNA was a key predictive factor for HBV DNA negative time in TDF monotherapy.

Management of Antiviral Resistance in Chronic Hepatitis B

The primary goal of therapy for chronic hepatitis B (CHB) is to prevent liver disease progression. Hepatitis B surface antigen (HBsAg) seroclearance or seroconversion is regarded as an optimal endpoint to discontinue treatment. However, HBsAg seroclearance occurs very rarely with nucleos(t)ide analog (NUC) treatment, and long-term, almost indefinite, NUC treatment is required for the majority of patients. In patients with drug-resistant hepatitis B virus (HBV), a combination of tenofovir disoproxil fumarate (TDF) and entecavir (ETV), which is currently regarded as the strongest combination therapy against HBV, would be potentially safe to prevent the emergence of additional HBV resistance mutations. However, long-term tolerance data are lacking, and cost may be an issue for combination therapies. Several recent, well-designed, randomized controlled trials have shown that TDF monotherapy provides similar antiviral efficacy compared with the combination of TDF and ETV. Furthermore, no additional HBV resistance mutations emerged during TDF monotherapy for up to 96 weeks. Considering a comparable antiviral efficacy, extremely low risk of TDF-resistance, lower cost, and better safety potential, TDF monotherapy would be a reasonable choice for the treatment of drug-resistant patients with CHB.

Treatment Efficacy and Safety of Tenofovir-Based Therapy in Chronic Hepatitis B: A Real Life Cohort Study in Korea

Background & Aims

We evaluated the efficacy and safety of Tenofovir disoproxil fumarate (TDF)-based therapy in naïve and treatment-experienced chronic hepatitis B (CHB) patients for 96 weeks in Korean real life practice.

Methods

A total of 209 CHB patients with a prescription for TDF at the Seoul and Daejeon St. Mary’s hospitals were enrolled from December 2012 to October 2014. We compared the virological responses and evaluated the renal safety of treatment-naive and treatment-experienced patients.

Results

An overall complete virological response (CVR) was achieved in 80.4% and 84.6% of patients at weeks 48 and 96, respectively. In a subgroup analysis, CVR at week 96 was present in 88.4%, 75.0%, 75.5%, and 83.3% of participants in the lamivudine-resistant (LAM-R) group, adefovir-resistant (ADV-R) group, multidrug-resistant (MDR) group, and suboptimal response group, respectively. In a multivariate analysis, ADV-R, MDR, hepatitis B virus DNA, and hepatitis B e antigen were independent predictors for CVR. With regard to renal safety, diabetes mellitus, cirrhosis, and an initial low estimated glomerular filtration rate were independent factors affecting creatinine elevation (≥0.5 mg/dL). Moreover, two patients with DM and cirrhosis experienced TDF-related Fanconi syndrome.

Conclusions

TDF-based therapy demonstrated sustained viral suppression and favorable safety during a 2-year treatment period. The LAM-R and suboptimal response groups showed comparable efficacy to the naïve group, while the ADV-R and MDR groups were significantly associated with a low CVR. Close monitoring of renal safety should be mandatory when treating CHB patients receiving TDF, particularly those with DM and cirrhosis.

Effectiveness and Safety of Tenofovir Disoproxil Fumarate in Chronic Hepatitis B: A 3-Year Prospective Field Practice Study in Germany

BACKGROUND AND AIMS

Multiple clinical trials have demonstrated the efficacy and safety of tenofovir disoproxil fumarate (TDF) in chronic hepatitis B (CHB). However, long-term efficacy and safety data for TDF in real-life clinical practice are limited.

METHODS

Prospective German field practice study in CHB-mono-infected patients. Patients were TDF-naïve but could have been treated previously with other HBV antivirals.

RESULTS

Efficacy analysis included 400 patients; 301 (75 %) completed 36 months of TDF treatment. Both treatment-naïve and treatment-experienced patients showed a rapid decline in HBV DNA within 3 months of TDF initiation. After 36 months, HBV DNA < 69 IU/mL was achieved by 91 % of treatment-naïve patients (90 and 92 % in hepatitis B "e" antigen [HBeAg]-positive and [HBeAg]-negative, respectively) and 96 % of treatment-experienced patients (93 and 97 %, respectively). Three patients experienced virologic breakthrough, all with reported non-compliance. Overall, 5.7 % HBeAg-positive and 2.2 % HBeAg-negative patients lost hepatitis B surface antigen. Safety data were consistent with the known TDF safety profile; the most commonly reported adverse events possibly related to TDF were fatigue (2.0 %) and headache (2.0 %). Few patients (1.3 %) experienced renal-related adverse reactions. Creatinine clearance remained relatively stable over time; patients responded favorably where TDF was dose adjusted per label for decreased creatinine clearance.

CONCLUSIONS

TDF showed a favorable tolerability profile and induced rapid and sustained suppression of HBV DNA in patients with CHB treated for up to 3 years in routine clinical practice, irrespective of treatment history. Efficacy and safety in this heterogeneous patient population were consistent with data from clinical trials.

Three-year efficacy and safety of tenofovir in nucleos(t)ide analog-naïve and nucleos(t)ide analog-experienced chronic hepatitis B patients

BACKGROUND AND AIMS

This study compared the efficacy and safety of tenofovir disoproxil fumarate (TDF) up to 3 years of innucleos(t)ide analog (NA)-naïve and NA-experienced chronic hepatitis B (CHB) patients.

METHODS

Tenofovir disoproxil fumarate-treated NA-naïve and NA-experienced CHB patients were retrospectively analyzed.

RESULTS

After 3 years of TDF therapy, 97.7%, 71%, and 45.5% NA-naïve patients achieved a virological response, alanine aminotransferase normalization, and hepatitis B e antigen seroconversion, respectively. Compared with NA-naïve patients, NA-experienced patients without drug resistance and infected with lamivudine/telbivudine-resistant mutants showed similar results. In contrast, patients previously infected with adefovir-resistant mutants and with a suboptimal entecavir response showed significantly lower rates of virological response and hepatitis B e antigen loss/seroconverion than NA-naïve patients. Mean estimated glomerular filtration rate markedly reduced within 12 months of TDF therapy; however, it did not decrease significantly during 12-36 months of treatment. Diabetes mellitus was an independent predictor of a ≥ 0.5 mg/dL increase above baseline in serum creatinine level, and age, hypertension, diabetes mellitus, and baseline creatinine level were independent factors for > 20% decline in estimated glomerular filtration rate from baseline. Liver stiffness measurements improved significantly, but bone mineral density did not change significantly during treatment. Hepatocellular carcinoma incidence was low at 36 months. Age of > 60 years, cirrhosis, a low baseline platelet count and a high α-fetoprotein level at 12 months were significant predictors of hepatocellular carcinoma development.

CONCLUSIONS

Tenofovir disoproxil fumarate is effective and safe for NA-naïve and NA-experienced CHB patients and should be used cautiously in patients with comorbidities because of a renal dysfunction risk.

Tenofovir monotherapy versus tenofovir and entecavir combination therapy in patients with entecavir-resistant chronic hepatitis B with multiple drug failure: results of a randomised trial

OBJECTIVE

Little clinical data are available regarding the optimal treatment of patients who harbour entecavir (ETV)-resistant HBV.

DESIGN

In this multicentre randomised trial, patients who had HBV with ETV resistance-associated mutations and serum HBV DNA concentrations >60 IU/mL were randomised to receive tenofovir disoproxil fumarate (TDF, 300 mg/day) monotherapy (n=45) or TDF and ETV (1 mg/day) combination therapy (n=45) for 48 weeks.

RESULTS

Baseline characteristics were comparable between groups, including HBV DNA levels (median, 4.02 log10 IU/mL) and hepatitis B e antigen-positivity (89%). All patients had at least one ETV-resistance mutation: rtT184A/C/F/G/I/L/S (n=49), rtS202G (n=43) and rtM250L/V (n=7), in addition to rtM204V/I (n=90). All except one patient in the TDF group completed 48 weeks of treatment. At week 48, the proportion of patients with HBV DNA <15 IU/mL, the primary efficacy endpoint, was not significantly different between the TDF and TDF+ETV groups (71% vs. 73%; p>0.99). The mean change in HBV DNA levels from baseline was not significantly different between groups (-3.66 vs. -3.74 log10 IU/mL; p=0.81). Virological breakthrough occurred in one patient on TDF, which was attributed to poor drug adherence. At week 48, six and three patients in the TDF and TDF+ETV groups, respectively, retained their baseline resistance mutations (p>0.99). None developed additional resistance mutations. Safety profiles were comparable in the two groups.

CONCLUSIONS

TDF monotherapy for 48 weeks provided a virological response comparable to that of TDF and ETV combination therapy in patients infected with ETV-resistant HBV.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov ID NCT01639092.

Alternative Therapies for Chronic Hepatitis B Patients With Partial Virological Response to Standard Entecavir Monotherapy

BACKGROUND

Entecavir (ETV) is a first-line, oral antinucleoside agent for the treatment of chronic hepatitis B patients. Despite its high potency, some patients may still be viremic after prolonged therapy with ETV monotherapy. Long-term outcome data comparing maintained ETV monotherapy to alternative therapies in persistently viremic patients are limited. Our goal was to compare complete viral suppression (CVS) rates [hepatitis B DNA (HBV DNA)<40 to 60 IU/mL] with alternative therapies to continued ETV monotherapy in ETV partial responders.

METHODS

This is a retrospective cohort study consisting of 86 consecutive treatment-naive, ETV=0.5 mg partial responders (detectable HBV DNA after ≥12 mo on ETV) who maintained ETV=0.5 mg daily (n=29) or switched to either ETV=1.0 mg daily (n=32) or ETV/tenofovir (TDF)=0.5 mg/300 mg (n=25) in 3 US GI/liver clinics from January 2005 to January 2012. Patients were identified by International Classification of Diseases, Ninth Revision query and data were collected by individual chart review. For those who remained on ETV=0.5 mg, comparison at regimen "switch time" was done using values at 12 months from initial ETV therapy. Rates of CVS were evaluated using Kaplan-Meier methods. Multivariate Cox proportional hazard models were used to estimate hazard ratio (HR) relating to potential predictors to the desirable outcomes of CVS.

RESULTS

In all therapy groups, the majority of patients were Asian (93.1% to 100.0%), male (64.0% to 68.8%), and hepatitis B e antigen-positive (95.8% to 100.0%) and had similar baseline alanine aminotransferase (ALT) levels. However, baseline HBV DNA (7.0 vs. 7.9 vs. 7.8 log10 IU/mL, P=0.05) and HBV DNA at regimen switch point (2.9 vs. 3.7 vs. 3.6 log10 IU/mL, P=0.0014) were lower in the ETV=0.5 mg cohort compared with those switched to ETV=1.0 mg or ETV/TDF, respectively. The ETV=0.5 mg cohort also had the shortest duration of ETV=0.5 mg therapy before switch (11.8 vs. 13.5 vs. 19.2 mo, P<0.0001). After the switch point, more patients on ETV/TDF achieved CVS compared with those on ETV=0.5 mg or ETV=1.0 mg at month 6 (77.3% vs. 13.8% vs. 9.4%), month 12 (86.4% vs. 40.5% vs. 25.0%), and month 18 (100% vs. 70.2% vs. 33.3%). Compared with the ETV=0.5 mg and ETV=1.0 mg groups, the ETV/TDF group also had higher rates of ALT normalization at month 6 (73.0% vs, 46.4% vs. 63.0%), month 12 (79.7% vs. 69.5% vs. 77.9%), and month 18 (100.0% vs. 69.5% vs. 86.8%), respectively. The multivariate analyses, inclusive of baseline age and treatment duration on initial therapy with ETV=0.5 mg, indicated that the ETV/TDF combination (HR=12.19, P<0.0001) was independently and positively associated with CVS, whereas high HBV DNA levels at baseline (HR=0.77, P=0.02) and at switch point (HR=0.46, P=0.002) were negatively associated with CVS. ETV=1.0 mg dose was not a predictor for CVS compared with ETV=0.5 mg.

CONCLUSIONS

Following adjustments for HBV DNA levels and prior treatment duration, ETV/TDF combination therapy independently predicted superior viral suppression and ALT normalization in partial responders to ETV=0.5 mg daily compared with ETV=0.5 mg or ETV=1.0 mg monotherapy. In patients who continued to be viremic after 12 months of ETV=0.5 mg, one third were still viremic after another 18 months on the same therapy. Alternative therapies should be considered for these patients.

Asian-Pacific clinical practice guidelines on the management of hepatitis B: a 2015 update

Worldwide, some 240 million people have chronic hepatitis B virus (HBV), with the highest rates of infection in Africa and Asia. Our understanding of the natural history of HBV infection and the potential for therapy of the resultant disease is continuously improving. New data have become available since the previous APASL guidelines for management of HBV infection were published in 2012. The objective of this manuscript is to update the recommendations for the optimal management of chronic HBV infection. The 2015 guidelines were developed by a panel of Asian experts chosen by the APASL. The clinical practice guidelines are based on evidence from existing publications or, if evidence was unavailable, on the experts' personal experience and opinion after deliberations. Manuscripts and abstracts of important meetings published through January 2015 have been evaluated. This guideline covers the full spectrum of care of patients infected with hepatitis B, including new terminology, natural history, screening, vaccination, counseling, diagnosis, assessment of the stage of liver disease, the indications, timing, choice and duration of single or combination of antiviral drugs, screening for HCC, management in special situations like childhood, pregnancy, coinfections, renal impairment and pre- and post-liver transplant, and policy guidelines. However, areas of uncertainty still exist, and clinicians, patients, and public health authorities must therefore continue to make choices on the basis of the evolving evidence. The final clinical practice guidelines and recommendations are presented here, along with the relevant background information.

Tenofovir rescue therapy in chronic hepatitis B patients who failed previous nucleoside analogue treatment

Background

Tenofovir (TDF) is considered as the first line therapy for chronic hepatitis B. This study presents the results of TDF monotherapy in patients who failed previous nucleoside analogue treatment.

Methods

The study included 29 patients treated with TDF 245 mg once daily for 18 months after lamivudine monotherapy (LAM arm: n = 15) or sequential therapy with lamivudine and entecavir (LAM → ETV arm: n = 14). The previous antiviral therapy was discontinued due to lack of efficacy. All patients had HBV DNA between 2.1 and 8.23 log₁₀ IU/ml and 15 were HBeAg-positive, while 45 % of patients had increased ALT activity. Undetectable HBV DNA (<20 IU/ml) at months 3, 6, 12 and 18 was the primary endpoint in the study, while HBeAg/HBsAg loss/seroconversion and ALT normalisation were secondary endpoints.

Results

Primary nonresponse to TDF was not observed. HBV DNA was undetectable in 80, 80, 80 and 93 % in LAM arm and 50, 71, 86 and 86 % in LAM → ETV arm patients, at 3, 6, 12 and 18 months of TDF therapy, respectively. One patient achieved anti-HBeAg seroconversion. 86.5 % of patients had normal ALT activity at the end of the study. The baseline HBV DNA load, HBeAg status and the length of the duration of TDF therapy appeared significantly associated with the response to the therapy. HBV DNA clearance occurred faster in HBeAg-negative patients than in those positive for HBeAg.

Conclusions

TDF is an effective antiviral medication in patients with previous exposure to LAM or LAM and ETV. Final proportion of patients who achieved undetectable HBV DNA and had normal ALT activity in both arms, was similar.

Tenofovir-based alternate therapies for chronic hepatitis B patients with partial virological response to entecavir

Entecavir (ETV) is a first-line antiviral therapy for treating chronic hepatitis B (CHB); however, some patients have suboptimal response to ETV. Currently, there are limited data on how to approach these patients. Therefore, our aim was to compare the effectiveness of two alternate therapies--tenofovir (TDF) monotherapy and combination therapy of ETV+TDF--in CHB patients with ETV partial virological response. We conducted a retrospective study of 68 patients who had partial virological response to ETV, defined as having detectable HBV DNA following at least 12 months of ETV, and were switched to TDF monotherapy (n = 25) or ETV+TDF (n = 43). Patients were seen in seven US liver/community-based clinics and started on ETV between 2005 and 2009. The majority of patients were male; the vast majority were Asian and had positive hepatitis B e antigen (HBeAg). Patients in both groups had similar pretreatment characteristics. Complete viral suppression (CVS) rates with TDF monotherapy and ETV+TDF were similar after 6 months (71% vs 83%, P = 0.23) and 12 months (86% vs 84%, P = 0.85), and there was no statistically significant difference in CVS rates even when only patients with higher HBV DNA levels at switch (>1000 IU/mL) were evaluated. Multivariate analysis indicated that ETV+TDF was not an independent predictor of CVS compared to TDF monotherapy (OR = 1.19, P = 0.63). In conclusion, TDF monotherapy and ETV+TDF are comparable in achieving CVS in CHB patients with partial virological response to ETV. Long-term alternate therapy with one pill (TDF monotherapy) vs two pills (ETV+TDF) could lead to lower nonadherence rates and better treatment outcomes.

Tenofovir monotherapy after achieving complete viral suppression on entecavir plus tenofovir combination therapy

OBJECTIVES

It is unclear whether patients with chronic hepatitis B with partial response to entecavir (ETV) who have achieved complete viral suppression (CVS) with ETV plus tenofovir (TDF) combination therapy maintain CVS if switched to TDF or ETV. Our goal was to examine virologic outcomes in such patients.

METHODS

This is a retrospective cohort study of 57 ETV partial responders with chronic hepatitis B who showed CVS on ETV+TDF combination therapy, who were switched back to monotherapy with either ETV (n=16) or TDF (n=18), or continued on combination therapy (n=23). The majority of patients were Asian (91%) and male (65%), with a mean age of 41±12 years.

RESULTS

The patients switched back to ETV had significantly higher rates of virologic breakthrough by 6 months after the switch compared with their TDF counterparts (88 vs. 39%, P=0.004). Patients who remained on ETV+TDF also had virologic breakthrough, due to either confirmed or suspected nonadherence. On multivariate analysis inclusive of age, sex, and hepatitis B virus DNA levels at initiation of combination therapy, ETV (compared with TDF) was found to be an independent predictor for virologic breakthrough (odds ratio 112.7, P=0.03), as well as duration of CVS of less than 12 months while on ETV+TDF (odds ratio 60.2, P=0.03).

CONCLUSION

TDF monotherapy, especially in those who have had CVS for at least 12 months on combination therapy, may be considered for some ETV partial responders who have achieved CVS with combination therapy, given the financial advantage and convenience of monotherapy.

Clinical course of partial virological responders under prolonged entecavir monotherapy in patients with chronic hepatitis B

Studies about long-term entecavir (ETV) therapy for partial virological response (PVR) are lacking. This study aimed to assess the clinical course of PVR patients receiving ETV therapy and analyze the efficacy of tenofovir (TDF). We retrospectively evaluated 130 patients who showed a PVR to ETV. Among these patients, 102 were nucleot(s)ide analogue (NUC)-naïve and 28 were lamivudine (LAM)-experienced. The cumulative rates of VR were 54.1%, 70.8%, and 83.7% for the NUC-naïve group and 37.0%, 42.8%, and 42.8% for the LAM-experienced group after 24, 36, and 48 months of ETV therapy, respectively (P  = 0.008). Low HBV DNA level at 12 months (P < 0.001) and absence of a LAM treatment history (P  = 0.031) were significant associated factors for VR. In VR prediction at 36 months of ETV therapy in NUC-naïve patients, HBV DNA level <95 IU/ml at 12 months showed a 92.9% sensitivity and a 78.3% specificity (AUROC, 0.909; P < 0.001). ETV resistance did not develop in NUC-naïve patients with HBV DNA levels <95 IU/ml at 12 months. The cumulative probability of VR in patients who switched to or additionally received TDF was 91.3% at 15 months. Prolonged ETV therapy induced a VR without the risk of ETV resistance in NUC-naïve patients with HBV DNA levels <95 IU/ml at 12 months. All patients with LAM-experienced or NUC-naïve with HBV DNA levels ≥95 IU/ml at 12 months should be switched to TDF rescue therapy.

Tenofovir in the treatment of naïve and refractory chronic Hepatitis B: A single center experience in Saudi Arabia

BACKGROUND/AIMS

Tenofovir disoproxil fumarate (TDF) is a nucleotide analog used in the treatment of chronic hepatitis B (CHB) infection. This study evaluated the efficacy of TDF in achieving undetectable HBV DNA after 48 weeks of treatment in a Saudi cohort of CHB patients.

PATIENTS AND METHODS

This retrospective study included patients treated at a tertiary care center in Saudi Arabia from January 2009 to December 2012. Of the 68 eligible patients, 51 were treatment naïve and 17 were treatment-refractory. Twenty-three patients tested positive for HBeAg. The remaining 45 patients were HBeAg-negative.

RESULTS

The mean HBV DNA viral load decreased from 95 million IU/mL at baseline to 263 IU/mL after 48 weeks of treatment (P < 0.001). Overall, 62% of patients achieved a complete virological response (CVR) and 37% a partial virological response (PVR). Respective CVR and PVR rates according to subgroup were: HBeAg-positive (21.7% and 78.3%) and HBeAg-negative (84.4% and 15.6%). At 48 weeks, HBV DNA was undetectable in 66.7% of treatment-naÏve and 53% of treatment-refractory patients (P = 0.3). Seroconversion occurred in 13 (57%) of HBeAg-positive patients. Two (3%) of the HBeAg-negative patients lost HBsAg at follow up. Mean alanine aminotransferase decreased significantly from 134 U/L before treatment to 37 U/L at 48 weeks (P < 0.001). Significant adverse events were not encountered during the study period.

CONCLUSION

Forty-eight weeks of treatment with TDF reduced HBV DNA to undetectable levels in more than half of our patients regardless of whether they were treatment-naïve or refractory. HBeAg-negative (vs positive) patients experienced a better response rate.

Current developments in nucleoside/nucleotide analogues for hepatitis B

There had been remarkable development in nucleos(t)ide analogues (NAs) and evolution in treatment strategies in last 15 years. Currently, there are five NAs available for chronic hepatitis B treatment, namely lamivudine, telbivudine and entecavir (nucleoside analogues), adefovir dipivoxil and tenofovir disoproxil fumarate (nucleotide analogues). The advantages of relatively infrequent side effects and easy administration per oral make NAs popular treatment options. The major drawback of earlier generation NAs is the risk of emergence of drug resistance. Current international guidelines recommend the use of more potent agents with high genetic barriers to resistance including entecavir and tenofovir as first line chronic hepatitis B treatment. However, there is no consensus regarding the subsequent treatment regimens in patients with suboptimal responses to NAs. De novo combination therapy of two NAs, response-guided therapy and roadmap concept in NAs with subsequent switch or add-on therapy can also potentially improve treatment efficacy and avoid resistance.

Long-term efficacy and emergence of multidrug resistance in patients with lamivudine-refractory chronic hepatitis B treated by combination therapy with adefovir plus lamivudine

BACKGROUND

Few studies have investigated the emergence of multidrug resistance to adefovir dipivoxil (ADV) plus lamivudine (LAM) combination therapy for patients with LAM-refractory chronic hepatitis B (CHB). In this retrospective study, we investigated the long-term clinical course of these patients with or without multidrug resistance mutations.

METHODS

We analyzed 406 Japanese patients with LAM-refractory CHB treated with combination therapy with follow-up for a median of 5.4 (0.5-9.5) years. Multidrug resistance of hepatitis B virus (HBV) DNA was analyzed using direct sequencing or cloning methods at baseline and viral breakthrough or insufficient decline during combination therapy.

RESULTS

Ratio of patients with undetectable serum HBV DNA levels (<2.6 log copies/mL) during combination therapy was 63, 72, 75, 79, 82, 80 and 85 % at years 1 through 7, respectively. Substitutions associated with multidrug resistance were identified in 11 patients (2.7 %) at baseline, and in 12 patients (3 %) during therapy. HBV DNA levels of patients with rtA181S mutation at baseline and emergence of rtA181T + rtN236T double mutation or a wide variety of mutations during combination therapy could not be suppressed. Moreover, using ultra-deep sequencing, rtA181T/V mutations were detected at baseline in 7 of 10 patients with emergent multidrug resistance during combination therapy, although 6 of these 7 patients had very low frequency (<1 %) variants.

CONCLUSION

Long-term ADV plus LAM combination therapy is effective in LAM-refractory patients. However, HBV DNA levels of the patients with multidrug resistance at baseline or during combination therapy sometimes could not achieve complete suppression or were re-elevated after a decrease.

HBV-DNA level at 6 months of entecavir treatment predicts HBeAg loss in HBeAg-positive chronic hepatitis B patients

BACKGROUND/PURPOSE

To evaluate whether on-treatment HBV-DNA level could predict the treatment response to entecavir in hepatitis B e antigen (HBe)-positive chronic hepatitis B (CHB) patients.

METHODS

A total of 68 treatment-naïve HBeAg-positive patients (75% male, mean age at 46.6 ± 11.9 years) receiving at least 2 years of entecavir therapy were enrolled. The primary therapeutic endpoint was HBeAg loss. On-treatment complete virological response was defined as serum HBV-DNA < 63 IU/mL.

RESULTS

The median baseline alanine aminotransferase (ALT) and HBV-DNA levels were 199.5 (27-1622) U/L and 7.7 (3.8-13.2) log10 IU/mL, respectively. The median treatment duration was 31.7 (24.3-69.6) months. The rate of HBeAg loss at 2 years was 30.9%. By univariate analysis, on-treatment complete virological response at Month 6 was associated with HBeAg loss at 2 years (p = 0.019). After adjustment for age, sex, cirrhosis, baseline ALT, and HBV-DNA levels, this factor remained significant in multivariate analysis (odds ratio: 4.35; 95% confidence interval: 1.24-15.24, p = 0.021).

CONCLUSION

On-treatment complete virological response at Month 6 is a favorable factor predictive of HBeAg loss at 2 years of entecavir therapy. Therefore, measurement of serum HBV-DNA level at 6 months of entecavir therapy is optimal to predict HBeAg loss at 2 years of therapy in HBeAg-positive CHB patients.

Efficacy and safety of tenofovir-based rescue therapy for chronic hepatitis B patients with previous nucleo(s/t)ide treatment failure

BACKGROUND/AIMS

We investigated the efficacy and safety of tenofovir disoproxil fumarate (TDF)-based treatment in chronic hepatitis B (CHB) patients who failed previous antiviral therapies.

METHODS

Seventeen patients who failed to achieve virological responses during sequential antiviral treatments were included. The patients were treated with TDF monotherapy (four patients) or a combination of TDF and lamivudine (13 patients) for a median of 42 months. Hepatitis B virus (HBV) DNA and hepatitis B e antigen (HBeAg) were measured, and renal function was also monitored.

RESULTS

Prior to TDF therapy, 180 M, 204 I/V/S, 181 T/V, 236 T, and 184 L mutations were detected. After TDF therapy, the median HBV DNA level decreased from 4.6 log10 IU/mL to 2.0 log10 IU/mL and to 1.6 log10 IU/mL at 12 and 24 months, respectively. HBV DNA became undetectable (≤20 IU/mL) in 14.3%, 41.7%, and 100% of patients after 12, 24, and 48 months of treatment, respectively. HBeAg loss was observed in two patients. Viral breakthrough occurred in five patients who had skipped their medication. No significant changes in renal function were observed.

CONCLUSIONS

TDF-based rescue treatment is effective in reducing HBV DNA levels and is safe for patients with CHB who failed prior antiviral treatments. Patients' adherence to medication is related to viral rebound.

Options for the management of antiviral resistance during hepatitis B therapy: reflections on battles over a decade

Although much advancement has been achieved in the treatment of chronic hepatitis B, antiviral resistance is still a challenging issue. Previous generation antiviral agents have already developed resistance in a number of patients, and it is still being used especially in resource limited countries. Once antiviral resistance occurs, it predisposes to subsequent resistance, resulting in multidrug resistance. Therefore, prevention of initial antiviral resistance is the most important strategy, and appropriate choice and modification of therapy would be the cornerstone in avoiding treatment failures. Until now, management of antiviral resistance has been evolving from sequential therapy to combination therapy. In the era of tenofovir, the paradigm shifts again, and we have to decide when to switch and when to combine on the basis of newly emerging clinical data. We expect future eradication of chronic hepatitis B virus infection by proper prevention and optimal management of antiviral resistance.

Continuous long-term entecavir therapy in naïve chronic hepatitis B patients showing partial virologic response

Background/Aims

We investigated the efficacy of continuous long-term entecavir 0.5 mg treatment in naïve chronic hepatitis B patients showing a partial virologic response (PVR).

Methods

A total of 227 patients were included. PVR was defined as a more than 1 log₁₀ IU/mL decline in detectable serum hepatitis B virus (HBV) DNA by polymerase chain reaction (PCR; ≥20 IU/mL) at week 48. A complete virologic response (CVR) was defined as undetectable serum HBV DNA by PCR (<20 IU/mL) at week 48.

Results

At week 48, the rate of the PVR was 64/227 (28.2%). Among patients with PVR, the cumulative rates of virologic response (serum HBV DNA <20 IU/mL) at weeks 96 and 144 were 45.2% and 73.8%, respectively. The cumulative rates of genotypic resistance were not significantly different between patients with a PVR and patients with a CVR (p=0.057). However, the cumulative rates of virologic breakthrough were higher in patients with PVR than in patients with CVR (4% vs 0% and 11.2% vs 0% at weeks 96 and 144, respectively; p<0.001).

Conclusions

Long-term continuous entecavir 0.5 mg treatment in patients with a PVR resulted in an additional virologic response without a significant increase in genotypic resistance. However, the rate of virologic breakthrough was higher in the partial responders.

Chronic hepatitis B: what should be the goal for new therapies?

Chronic hepatitis B can currently be medically managed with either pegylated interferon-alpha (pegIFN-α) or one of the five nucleos(t)ide analog Direct Acting Antivirals (DAAs) that inhibit the hepatitis B virus (HBV) DNA polymerase. While pegIFN-α is effective in approximately one-third of the treated patients, the polymerase inhibitors significantly reduce viral load in the vast majority of those treated. However, neither pegIFN-α nor nucleosi(t)de analogs are capable of reliably eliminating the virus and achieving a cure. Moreover, the interferons and polymerase inhibitors are recommended by US, European and Asian professional society practice guidelines for use in only a subset of those infected with HBV. This subset is the population with the greatest levels of circulating viral DNA and abnormal liver function. Although this is the population at the highest risk for cirrhosis and liver cancer, those who fall outside the treatment guidelines, with low levels of viral replication and normal serum ALTs, may also benefit from antiviral therapy. The questions are thus: are new classes of drugs needed to manage chronic hepatitis B? Is a cure possible? Is a cure even necessary? It is therefore important to define the meaning of a cure and determine what the goals of new therapies should be. In this article, we address those questions and propose two operational definitions of medically attainable cures. The first is a "functional cure" based on the clinical outcome, in which the patient's life expectancy becomes the same as that of an individual who has resolved his HBV infection without therapy. Because such an outcome cannot be measured over the short term, we also define an "apparent virological cure," based on the stable off-drug suppression of HBV viremia and antigenemia and the normalization of ALTs and other laboratory tests. We suggest that such a virological cure should be the goal of future therapeutics in all patients with chronic hepatitis B. The extent to which a virological cure predicts a functional cure will only be determined by long-term follow-up.

Tenofovir monotherapy and tenofovir plus entecavir combination as rescue therapy for entecavir partial responders

BACKGROUND AND AIMS

Despite high potency, a significant proportion of patients treated with entecavir achieve only partial viral suppression. Our goal was to examine the complete viral suppression rate (undetectable HBV DNA PCR levels) with alternative therapies in such patients.

METHODS

We retrospectively studied 42 consecutive patients with partial response to entecavir (detectable HBV DNA at ≥12 months of therapy) who were treated at three clinics with rescue therapies: entecavir + adefovir (n = 5), tenofovir (n = 6), and entecavir + tenofovir (n = 31). Antiviral resistance was excluded by negative mutation analysis and/or absence of virologic breakthrough (increase >1 log(10)IU/mL from nadir).

RESULTS

All patients were Asian and 57 % were male with a median age of 36 (22-64) years. Only a few patients had prior exposure to lamivudine (7 %) or adefovir (7 %). Almost all patients (95 %) had positive HBeAg. Overall, the complete viral suppression rate was 79 %, and the alanine aminotransferase normalization rate was 83 % in entecavir partial responders after 6 months on rescue therapies. Cumulative complete viral suppression rates were significantly different (P = 0.0164) among the entecavir + adefovir, tenofovir, and entecavir + tenofovir treatment groups at 6 months (20 vs. 83 vs. 83 %, respectively) and 12 months (20 vs. 100 vs. 97 %). All three patients without complete viral suppression on entecavir + adefovir became aviremic 6 months after switching to entecavir + tenofovir.

CONCLUSIONS

Virologic response to entecavir + tenofovir combination therapy and tenofovir monotherapy appeared to be similar in most patients, but not with the entecavir + adefovir combination.

Clonal analysis of the quasispecies of antiviral-resistant HBV genomes in patients with entecavir resistance during rescue treatment and successful treatment of entecavir resistance with tenofovir

BACKGROUND

Clonal analysis of quasispecies of resistant HBV genomes in patients with entecavir (ETV) resistance receiving lamivudine (3TC) plus adefovir (ADV) rescue therapy has never been performed.

METHODS

A sample of 10 patients with ETV resistance who were switched to 3TC+ADV treatment were analysed for changes in viral quasispecies. Serum samples at baseline, and at months 3 and 6 of 3TC+ADV treatment could be clonally analysed in 7 of 10 patients; 3-82 clones per sample (total 1,068 clones, mean 63) were sequenced.

RESULTS

3TC+ADV therapy led to a modest decline in HBV DNA. Almost all clones had L180M and M204V 3TC resistance mutations before and during combination therapy. All clones had ≥1 of the S202G, T184F, T184A, T184L, T184I and M250V ETV resistance mutations. The percentages of detected clones bearing 3TC (rtL180M and rtM204V) and ETV mutations did not change with rescue 3TC+ADV therapy. In 7 of 8 patients with detectable HBV DNA (median 5.17 log(10) copies/ml) after a median 24 months of ADV therapy, HBV DNA became undetectable with 3TC plus tenofovir after 6 months of treatment.

CONCLUSIONS

In patients with ETV resistance tenofovir is effective. Clonal analysis data indicate no selection of specific HBV mutants during rescue 3TC+ADV.

The management of chronic hepatitis B in Asian Americans

Hepatitis B virus (HBV) infection is common with major clinical consequences worldwide. In Asian Americans, the HBsAg carrier rate ranges from 7 to 16%; HBV is the most important cause of chronic hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). Patients are first diagnosed at different stages of clinical disease, which is categorized by biochemical and virologic tests. Patients at risk for liver complications should be identified and offered antiviral therapy. The two antiviral agents recommended for first-line treatment of chronic hepatitis B (CHB) are entecavir and tenofovir. The primary goal of therapy is sustained suppression of viral replication to achieve clinical remission, reverse fibrosis, and prevent and reduce progression to end-stage liver disease and HCC. Asian patients with chronic hepatitis, either HBeAg-positive or -negative, with HBV DNA levels >10(4) copies/mL (>2,000 IU/mL) and alanine aminotransferase (ALT) values above normal are candidates for antiviral therapy. HBeAg-negative patients with HBV DNA >10(4) copies/mL (>2,000 IU/mL) and normal ALT levels but who have either serum albumin ≤3.5 g/dL or platelet count ≤130,000 mm(3), basal core promoter mutations, or who have first-degree relatives with HCC should be offered treatment. Patients with cirrhosis and detectable HBV DNA must receive antiviral therapy. Considerations for treatment include pregnant women with high viremia, coinfected patients, and those requiring immunosuppressive therapy. In HBsAg-positive patients with risk factors, lifelong surveillance for HCC with alpha-fetoprotein testing and abdominal ultrasound examination at 6-month intervals is required. These recommendations are based on a review of relevant literature and the opinion of a panel of Asian American physicians with expertise in hepatitis B treatment.