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 × 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.     

Development of HCC in patients receiving adefovir dipivoxil for lamivudine‐resistant hepatitis B virus mutants

Aim: To identify factors for the development of hepatocellular carcinoma (HCC) in the patients who receive adefovir add‐on lamivudine for treatment of lamivudine‐resistant hepatitis B virus (HBV) mutants. Methods: A total of 247 patients who developed lamivudine‐resistant HBV mutants, with an increase of HBV DNA ≥ 1 log copies/mL, received adefovir dipivoxil 10 mg add‐on lamivudine 100 mg daily during a median of 115 weeks (range: 25–282 weeks). They were followed for the development of HCC by imaging modalities every 3?6 months. Results: HCC developed in 18 of the 247 (7.3%) patients. Eight factors were in significant association with the development of HCC by the univariate analysis. They included age, cirrhosis, platelet counts, levels of bilirubin, aspartate aminotransferase (AST), alanine aminotransferase and α‐fetoprotein, as well as YMDD mutants at the start of adefovir dipivoxil. By the multivariate analysis, AST levels, YIDD mutants, cirrhosis and age were independent factors for the development of HCC. By the Kaplan‐Meier analysis, AST levels ≥ 70 IU/L, YIDD mutants, cirrhosis and age ≥ 50 years increased the risk of HCC (P = 0.018, P = 0.035, P = 0.002 and P = 0.014, respectively). HCC developed more frequently in the patients with than without cirrhosis at the start of adefovir (10/59 [16.9%] vs. 8/188 [4.3%], P = 0.002). Conclusion: HCC can develop in cirrhotic patients receiving adefovir add‐on lamivudine. Hence, the patients with baseline AST ≥ 70 IU/L and YIDD mutants would need to be monitored closely for HCC.     

Failure of adefovir 20 mg to improve suboptimal response in lamivudine‐resistant hepatitis B patients treated with adefovir 10 mg and lamivudine

Summary. Nine patients with lamivudine‐resistant chronic hepatitis B infection who had been treated with adefovir 10 mg/day and had had a suboptimal response but did not have genotypic resistance to adefovir were treated with high‐dose adefovir (20 mg/day). The response to the increased dose of adefovir was compared with the response in 15 patients with a suboptimal response who did not receive an increase in the dose of adefovir. The increase in the dose of adefovir did not lead to a significant reduction in hepatitis B DNA when compared with patients maintained on the standard dose. These data suggest that increasing the dose of adefovir in patients with a suboptimal response does not lead to an improved response.     

Characteristics of adefovir resistance in patients with or without lamivudine‐resistant hepatitis B virus treated with adefovir: a 4‐year experience

Background/Aim: We investigated the 4‐year incidence and predictors of adefovir resistance in chronic hepatitis B patients with or without lamivudine (LAM)‐resistance treated with adefovir dipivoxil with or without short‐term LAM overlapping. Methods: One hundred and two LAM‐resistant patients and 79 without LAM resistance (36 naïve and 43 prior LAM exposure) treated with adefovir for >12 months were prospectively examined. Results: Cumulative incidences of adefovir resistance at month 12, 24, 36 and 48 were 3.9, 21.1, 31.8 and 43% respectively in LAM‐resistant patients. Cirrhosis was a significant risk factor for adefovir resistance. A similar rate of adefovir resistance was observed for LAM‐resistant patients and those with prior LAM exposure without resistance. Regarding LAM‐resistant patients, compared with those having hepatitis B virus (HBV) DNA levels <300 copies/ml, patients having HBV DNA levels >10⁴ copies/ml at week 24 of therapy had a hazard ratio (HR) of 9.8 for adefovir resistance development, while those without LAM resistance having the same HBV DNA levels at week 48 had a similar HR (9.5). Multidrug‐resistant (LAM+adefovir) variants were detected by direct sequencing in three of 35 LAM‐resistant patients treated with a switch to adefovir. Two of them had resistant mutations to both drugs on the same viral genome as determined by molecular cloning and sequencing. Conclusion: The incidence of adefovir resistance was high in LAM‐resistant patients treated with sequential adefovir. High HBV DNA levels at week 24 and 48 of therapy were the strongest predictors for adefovir resistance development in patients with and without LAM resistance respectively.     

阿德福韦酯单药挽救治疗对拉米夫定耐药的慢性乙型肝炎患者3年疗效观察

目的总结阿德福韦酯(ADV)单药挽救治疗拉米夫定(LAM)耐药慢性乙型肝炎患者效果,分析疗效影响因素,探讨单药挽救LAM耐药的可行性。方法 60例慢性乙型肝炎应用LAM耐药后入组挽救治疗。收集患者的基本特征:如年龄、性别、肝生化指标、HBV DNA及HBV M。纪录治疗持续时间及应答,并进行分组对照。结果 60例中,HBV DNA定量反弹≥1log10拷贝/ml 20例,HBV DNA测序rtM204I/V、rtL180M位点变异40例。生化学突破的LAM耐药患者,给予ADV单药治疗。完成156周治疗者42例。HBV DNA低复制组(基线水平HBV DNA 103～105拷贝/ml)治疗后第12至156周HBV DNA转阴率均为80.0%,高复制组(基线水平HBV DNA≥106拷贝/ml)转阴率为40.7%～44.7%,两组相比差异有统计学意义(P<0.01)。HBV DNA转阴率随治疗时间延长渐增加。治疗156周时,HBeAg阳性血清学转换率24.1%。4例因检测出rtA181V/I/S位点变异改用恩替卡韦(ETV)。结论 ADV单药挽救治疗LAM耐药慢性乙型肝炎,具有一定的疗效,且更适合于低病毒载量患者。     

Add‐on combination therapy with adefovir dipivoxil induces renal impairment in patients with lamivudine‐refractory hepatitis B virus

Summary. Combination therapy with adefovir dipivoxil (ADV) and lamivudine (LAM) is recommended for patients infected with LAM‐refractory hepatitis B virus (HBV). However, the effects of such therapy on renal function and serum phosphorus levels have not been fully evaluated. Combination therapy with ADV and LAM was given to 37 patients infected with LAM‐refractory HBV, including 17 with hepatic cirrhosis. Serum HBV DNA levels decreased to below 2.6 log₁₀ copies/mL in 23 (62%) of 37 patients at 12 months, 25 (78%) of 32 patients at 24 months, and 16 (84%) of 19 patients at 36 months. Except for one cirrhotic patient, serum alanine aminotransferase levels were below 50 IU/L in all patients during combination therapy. Serum creatinine levels increased in 14 (38%) of 37 patients, and serum phosphate levels decreased to below 2.5 mg/mL in 6 (16%) of 37 patients during combination therapy. Patients who received combination therapy for 36 months or longer had a significantly incidence of elevated serum creatinine levels. Fanconi syndrome occurred in a 57‐year‐old woman with cirrhosis after ADV was added to LAM. Combination therapy with ADV and LAM can maintain biochemical remission in patients with LAM‐refractory HBV. However, the dosing interval of ADV should be adjusted according to renal function and serum phosphate levels in patients receiving long‐term treatment.     

Low risk of adefovir resistance in lamivudine-resistant chronic hepatitis B patients treated with adefovir plus lamivudine combination therapy: two-year follow-up

BACKGROUND/AIMS: We studied the long-term efficacy (median follow-up of 28 months) of adefovir (ADV) in combination with lamivudine (LAM) in 132 LAM-resistant Japanese patients with chronic genotype C-dominant hepatitis B virus (HBV) infection. METHODS: The viral response (undetectable HBV-DNA by PCR assay) and the predictor of viral response were evaluated. The emergence of ADV-resistant mutants was investigated during the combination therapy. RESULTS: The cumulative probability of viral response was 69% at 12 months, and 81% at 24 months. Multivariate analysis identified baseline HBe antigen status (P=0.0001), aspartate aminotransferase level (AST) (P=0.001) and HBV-DNA level (P=0.002) as determinants of viral response to treatment. At the beginning of ADV therapy, substitutions at rtA181 (rtA181T and rtA181S) were identified in 3 patients (2.3%). In the remaining 129 patients, the rtM204 mutants were identified at baseline, and two (1.6%) of the 129 patients developed new ADV-resistant mutants; one was rtA181S and another was rtA181T plus rtN236T mutation. CONCLUSIONS: Adefovir and lamivudine combination therapy effectively suppressed viral replication and maintained the efficacy well in LAM-resistant patients with chronic HBV infection. Genotypic analysis indicated that the emergence of ADV-resistant mutants is rare, at least over a period of 2 years, in patients with combination therapy.     

Low efficacy of entecavir therapy in adefovir‐refractory hepatitis B patients with prior lamivudine resistance

Summary. We determined the virologic response, incidence of entecavir resistance, and evolution of lamivudine and adefovir‐resistant mutants during entecavir (ETV) therapy in adefovir‐refractory patients with prior lamivudine resistance. Forty adefovir‐refractory chronic hepatitis B patients with prior lamivudine resistance who had received entecavir for ≥6 months were included and monitored for virologic response and entecavir resistance. Ten per cent of patients achieved HBV DNA < 50 copies/mL by PCR after 24 weeks of ETV therapy, and an initial virologic response was observed in 12 of 40 patients (30%). Higher pretreatment ALT (P = 0.039) and the presence of the rtL180M mutation (P = 0.038) were associated with an initial virologic response. During a mean follow‐up of 11.4 months, four patients (10%) experienced virologic breakthrough, while ETV‐resistant mutants were detected in six patients (15%). YMDD and adefovir‐resistant mutants were detected in 57 and 35% of patients at baseline, respectively. At 48 weeks of therapy, 96 and 4% of patients had YMDD and adefovir‐resistant mutants, respectively. These data suggest an early development of ETV resistance and low antiviral response during ETV therapy in adefovir‐refractory patients with prior lamivudine resistance.     

Tenofovir plus lamivudine as rescue therapy for adefovir‐resistant chronic hepatitis B in hepatitis B e antigen‐positive patients with liver cirrhosis

Background/Aims: There is no consensus on the management of patients with adefovir (ADV)‐resistant hepatitis B virus (HBV) infection. The aim of this study was to investigate whether tenofovir disoproxil fumarate (TDF) combined with lamivudine (LMV) is effective and safe in patients with resistance to or non‐response to ADV. Methods: Six patients with HBV‐related cirrhosis, viral breakthrough during LMV therapy and viral breakthrough or non‐response during ADV therapy were treated daily with TDF plus LMV for at least 6 months. The HBV DNA level, alanine aminotransferase (ALT), the Child–Pugh score and serum creatinine were monitored. Genotypic LMV‐ or ADV‐resistant mutations were measured in stored samples. Results: In five of six patients, ADV‐resistant mutations at rt181 or rt236 were detected during ADV therapy. At 6 months of starting TDF/LMV combination, HBV DNA levels became undetectable (detection limit, 400 copies/ml) in four of six patients. Within 12 months, HBV DNA levels became undetectable in all patients, and ALT levels were normalized in four of six patients. These responses persisted up to the end of the observation period (median duration 16.5 months, range 6–21 months). The Child–Pugh scores improved in two of three patients with hepatic decompensation. No significant changes in serum creatinine were observed. Conclusion: Our data demonstrated that TDF plus LMV safely and markedly suppressed HBV replication in patients with resistance to or non‐response to ADV. This study suggests that this combination may be a promising rescue therapy for these patients, particularly those with liver cirrhosis or pre‐existing LMV resistance.     

Long-term efficacy of entecavir therapy in chronic hepatitis B patients with antiviral resistance to lamivudine and adefovir

No studies have reported the long-term effects of entecavir switching in patients with multidrug resistance who developed resistance after lamivudine/adefovir sequential therapy. We evaluated the efficacy of 96 weeks of entecavir therapy in patients with resistance to lamivudine/adefovir sequential therapy. In total, 33 patients with chronic hepatitis B virus (HBV) infection with evidence of active viral replication (HBV DNA levels ≥ 10(5) copies/mL) or a history of treatment failure to lamivudine/adefovir sequential therapy between April 2007 and July 2009 were treated with entecavir (1.0 mg daily) for at least 48 weeks. The rates of alanine transaminase (ALT) normalization and HBV DNA negativity were 66.7% (14/21) and 24.2% (8/33) at 48 weeks, respectively. The initial HBV DNA level was the only factor that was inversely associated with serum HBV DNA negativity after 48 weeks of entecavir therapy (P < 0.023). At 96 weeks, the rates of ALT normalization and HBV DNA negativity were 77.8% (7/9) and 16.7% (3/18), respectively. Viral breakthrough occurred in 21.2% (7/33) and 78.9% (15/19) of patients at 48 and 96 weeks, respectively. Patients who achieved a HBV DNA level of <4 log(10) copies/mL at 48 weeks maintained a similar HBV DNA level and a normal ALT level until 96 weeks. Entecavir monotherapy for 96 weeks was not efficacious for patients with lamivudine/adefovir-resistant HBV. The initial HBV DNA level was the only predictive factor for antiviral efficacy. However, patients who achieved a HBV DNA level of <4 log(10) copies/mL with a normal ALT level at 48 weeks should maintain, rather than stop, entecavir therapy.     

Interferon/long-term lamivudine combination therapy in anti-HBe positive chronic hepatitis B patients

BACKGROUND: Monotherapy with a single antiviral agent is insufficient in controlling hepatitis B virus infection in the majority of patients with anti-HBe positive chronic hepatitis B. Interferon/long-term lamivudine combination therapy was evaluated to determine if this strategy would improve treatment efficacy and reduce the emergence of lamivudine resistance. METHODS: In total, 36 consecutive anti-HBe positive patients were treated with interferon (3 MU subcutaneously three times weekly) and lamivudine (100 mg orally once a day) for 12 months. After completion of the combined treatment, all patients continued to receive lamivudine monotherapy indefinitely. RESULTS: Overall, 35 patients (97%) showed virological response at 12 months. Four patients (11%) cleared HBsAg and developed anti-HBs. During the follow-up time, after the discontinuation of interferon, of 30 +/- 12 months (range: 7-57 months), 13 patients (36%) exhibited breakthrough infection. The cumulative rates of breakthrough infection at the end of 1, 2, 3 and 4 years of treatment were 0%, 14%, 32%, and 59%, respectively. CONCLUSIONS: Combination therapy appears to be effective and may also delay the selection of lamivudine-resistant variants. However, controlled trials are definitely warranted to clarify the potential benefits of combination antiviral treatment over monotherapy.     

Application of allele-specific RNAi in hepatitis B virus lamivudine resistance

Understanding the consequences of mutation in the tyrosine-methionine-aspartate-aspartate (YMDD) motif of hepatitis B virus (HBV) genome on replication is critical for treating chronic hepatitis B with lamivudine. Allele-specific gene silencing by RNAi (allele-specific RNAi: ASP-RNAi) is an advanced application of RNAi techniques. Use of this strategy as a means for specifically inhibiting an allele expression of interest suggested that it can specifically suppress the expression of alleles causing disease without inhibiting the expression of corresponding wild-type alleles. However, no studies have used ASP-RNAi to address the issue of HBV lamivudine resistance. In this study, we applied ASP-RNAi into two long-term eukaryotic cell lines of full-length HBV containing either lamivudine-resistant mutants (HBV-YIDD) or wild type (HBV-WT) which we generated in previously. The designed siRNAs were also used in this eukaryotic expression system together with lamivudine. ELISA and real-time PCR were performed to monitor virus-specific protein synthesis and viral DNA replication. The results showed that the base substitutions conferring marked ASP-RNAi appeared to be largely present in positions 1, 3, 6, 11, 12, 15 and 19 of the sense strand of siRNAs which were different from the most sensitive positions of this application in eukaryotes. In addition, siRNA-lamivudine combinations did not possess the prominent anti-HBV activity we expected because of some unknown mechanisms. These findings recapitulated many of the features of ASP-RNAi in hepadnaviruses which provided a new insight into the development of a potent strategy against HBV drug resistance.     

乙型肝炎核心相关抗原对慢性乙型肝炎患者拉米夫定耐药的预测作用

目的评价乙型肝炎核心相关抗原（HBcrAg）对慢性乙型肝炎患者拉米夫定（LAM）耐药的预测作用。方法收集2009年1月至2011年12月期间住院和门诊收治的43例慢性乙型肝炎初治患者,拉米夫定治疗≥6个月,随访≥6个月,根据随访期间HBV DNA测序结果分为耐药组2l例,非耐药组22例。分别检测各研究节点ALT、HBsAg、HBeAg、HBcrAg、HBV DNA水平。计量资料两组问比较采用独立样本t检验,方差不齐采用Mann—Whitney U检验;计数资料采用卡方检验。相关性分析采用Spearman分析。影响因素采用Logistic回归分析。结果LAM抗病毒前HBcrAg与HBV DNA水平有较好的一致性,Spearman相关系数为0．863（P〈0．001）。LAM抗病毒治疗后,外周血HBcrAg与HBV DNA水平均有所下降,但HBcrAg下降速度与幅度均低于HBV DNA。Logistic回归分析显示,随访结束时HBcrAg水平可能为LAM耐药的影响因素（P〈0．01）。HBcrAg对LAM耐药预测价值较高,ROC曲线下面积为0．872（P〈0．001）。结论LAM抗病毒前外周血HBcrAg与HBV DNA有较好的一致性,随访结束时HB—crAg水平可较好的预测LAM耐药。