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.     

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

Summary. Both entecavir (ETV) and tenofovir (TDF) are potent antiviral agents for hepatitis B virus (HBV). Suboptimal response (SOR) following antiviral therapy is associated with an increased risk of subsequent treatment failure and viral resistance. It remains unclear whether switching to TDF is a reasonable approach in patients with SOR to ETV treatment. This study was aimed to determine how HBV patients with SOR to ETV respond to TDF monotherapy. Data of patients with SOR to ETV (failure to achieve >1 log₁₀ HBV‐DNA reduction during the last 24 weeks of ETV treatment) who were switched to TDF monotherapy during 2005 and 2010 were reviewed. Treatment adherence was assessed by pill‐count. Fourteen patients (2.9%) were identified from a total cohort of 482 ETV‐treated patients. All 14 patients were Chinese and were infected with HBV genotype C (71%) or B (29%). Nine patients were men, and the median age was 41.5 years (19–64). Twelve were treatment naïve (one lamivudine‐ and one peginterferon‐experienced patient); 85.7% were HBeAg positive. The median baseline HBV‐DNA was 7.55 (5.30–9.40) log₁₀ copies/mL, and 57% had abnormal serum alanine aminotransferase (ALT) levels. Precore and/or basal core promoter mutations were detected in four patients, whereas no genotypic resistance was detected at baseline and before switching to TDF. The median duration of ETV treatment was 64.5 (26–126) weeks. The median HBV‐DNA at the time of switching to TDF was 3.69 (3.00–4.90) log₁₀ copies/mL. The median HBV‐DNA reduction from baseline and during the last 6‐month observation period prior to switching to TDF was 4.04 (0.51–6.06) log₁₀ and 0.43 (?0.09–1.13) log₁₀ copies/mL, respectively. After the switching to TDF, all 14 patients (100%) achieved undetectable HBV‐DNA and ALT normalization within a median duration of 30 weeks. In 12 patients who were HBeAg positive, HBeAg seroconversion was observed in two patients after TDF treatment of 75‐ and 84‐weeks duration. There was no virological breakthrough observed after switching to TDF with a median follow‐up period of 50 (24–160) weeks. TDF treatment was safe and well tolerated. In conclusion, suboptimal response to ETV is rare (approximately 3%). TDF monotherapy is safe and very effective in the management of HBV patients with SOR to ETV.     

Tenofovir versus tenofovir plus entecavir for chronic hepatitis B with lamivudine resistance and entecavir resistance

We compared the viral suppressive efficacy of tenofovir disoproxil fumarate (TDF) mono‐rescue therapy (TDF group) and TDF plus entecavir (ETV) combination‐rescue therapy (TDF + ETV group) in chronic hepatitis B (CHB) patients with lamivudine resistance and entecavir resistance. One hundred and thirty‐three CHB patients with lamivudine and entecavir resistance were investigated. Ninety‐six patients were treated with TDF and 37 with TDF + ETV for at least 6 months. We compared the virologic response rate (HBV DNA level <20 IU/mL) between the two groups and identified the predictive factors of treatment outcome. There were no significant differences between the two groups in demographic characteristics. Up to 24 months [median: 18 (range 6‐24) months], 85.4% and 89.2% of the TDF group and TDF + ETV group, respectively, achieved a virologic response (P=.068). Only the HBV DNA level at baseline was significantly associated with a virologic response in the multivariate analysis. In a subanalysis of patients with HBV DNA levels ≥4 log (IU/mL) at baseline, a higher proportion of patients in the TDF + ETV group than the TDF group achieved a virologic response (92.9% vs 68.3%; P<.001), while 90% of patients with HBV DNA (IU/mL) levels <4 log in all both TDF and TDF + ETV groups achieved a virologic response. TDF mono‐rescue therapy is a reasonable option in patients with lamivudine resistance and entecavir resistance. However, the combination strategy should be considered in patients with high baseline HBV DNA levels.     

First-line treatment of chronic hepatitis B with entecavir or tenofovir in 'real-life' settings: from clinical trials to clinical practice

Entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are potent nucleos(t)ide analogues (NUCs) recommended as first-line monotherapies for chronic hepatitis B. In Phase III trials, ETV and TDF demonstrated superior efficacy, and comparable safety compared with other NUCs. In long-term clinical studies, both drugs achieved virologic response rates of around 95%, with very low rates of resistance development and good safety profiles. Clinical trials are conducted under standardized conditions with strict enrolment criteria that limit the heterogeneity of study populations. 'Real-life' populations tend to be composed of a wider range of patients, often older and with different morbidities, comorbidities that may impact treatment efficacy and co-factors, such as smoking and alcohol intake, which can have a direct impact on disease progression. Real-life studies provide better representations of everyday clinical practice and are important to confirm the results reported in clinical studies and to identify rare or late-emerging adverse events. In five 'real-life' studies of ETV in more than 1000 patients, up to 4 years of treatment resulted in virologic responses in 76-96% of patients. Two real-life studies of TDF reported response rates of 71-92% after up to 21 months of treatment. Low incidences of drug resistance and favourable tolerabilities were reported for both drugs, thus confirming the results from registration trials.     

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.     

替诺福韦酯治疗核苷和核苷酸类药物耐药慢性乙型肝炎患者的研究进展

替诺福韦酯为目前治疗慢性乙型肝炎的一线药物,叙述了其对拉米夫定、阿德福韦酯耐药患者及恩替卡韦治疗不佳和多重耐药患者治疗效果的研究进展,介绍了关于替诺福韦酯单药治疗和联合治疗效果的对比研究结果。认为替诺福韦酯安全性好,对包括孕妇在内的耐药患者有较好治疗效果,但在单药治疗和联合治疗效果对比方面,各项研究结果均无明显差异。     

Renal safety of tenofovir disoproxil fumarate and entecavir with hepatitis B immunoglobulin in liver transplant patients

Potent nucleos(t)ide analogues and hepatitis B immunoglobulin combinations are recommended after liver transplantation to prevent the recurrence of hepatitis B virus (HBV). Despite its proven efficacy, the renal safety of tenofovir disoproxil fumarate (TDF) has not been well established in liver transplant recipients. We aimed to assess the impacts of TDF and entecavir (ETV) on tubular and glomerular functions. We analysed 206 liver transplant patients treated with TDF (n = 102) or ETV (n = 104) plus hepatitis B immunoglobulin. Serum creatinine, phosphate and uric acid levels were measured. Proximal tubular dysfunction was defined as the presence of hypophosphatemia (<2 mg/dL) and hypouricemia (<2 mg/dL). Glomerular dysfunction was defined as an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m² accompanied by a ≥25% eGFR decline from baseline. During a median follow‐up of 42.5 months, 48 patients developed proximal tubular dysfunction (30.4% and 16.3% in the TDF and ETV groups; P = .017). Serum levels of phosphate and uric acid were significantly lower in the TDF group post‐LT. TDF (OR, 2.34; 95% CI, 1.16‐4.69; P = .017) and low body mass index (OR, 2.11; 95% CI, 1.06‐4.21; P = .034) were independent risk factors for proximal tubular dysfunction. The prevalence of glomerular dysfunction was not significantly different between the two groups (TDF 51.0% and ETV 54.8%; P = .582). TDF significantly increased the risk of proximal tubular dysfunction. Although the effect of TDF on glomerular function was comparable to that of ETV, glomerular dysfunction was common after liver transplant.     

Relationship between virological response and FIB-4 index in chronic hepatitis B patients with entecavir therapy

AIM: To investigate whether long-term low-level hepatitis B virus(HBV) DNA influences dynamic changes of the FIB-4 index in chronic hepatitis B(CHB) patients receiving entecavir(ETV) therapy with partial virological responses.METHODS: We retrospectively analyzed 231 nucleos-(t)ide(NA) na?ve CHB patients from our previous study(NCT01926288) who received continuous ETV or ETV maleate therapy for three years. The patients were divided into partial virological response(PVR) and complete virological response(CVR) groups according to serum HBV DNA levels at week 48. Seventy-six patients underwent biopsies at baseline and at 48 wk. The performance of the FIB-4 index and area under the receiver operating characteristic(AUROC) curve for predicting fibrosis were determined for the patients undergoing biopsy. The primary objective of the study was to compare the cumulative probabilities of virological responses between the two groups during the treatment period. The secondary outcome was to observe dynamic changes of the FIB-4 index between CVR patients and PVR patients.RESULTS: For hepatitis B e antigen(HBe Ag)-positive patients(n = 178),the cumulative probability of achieving undetectable levels at week 144 was 95%and 69% for CVR and PVR patients,respectively(P 0.001). In the Cox proportional hazards model,a lower pretreatment serum HBV DNA level was an independent factor predicting maintained viral suppression. The cumulative probability of achieving undetectable levels of HBV DNA for HBe Ag-negative patients(n = 53) did not differ between the two groups. The FIB-4 index efficiently identified fibrosis,with an AUROC of 0.80(95%CI: 0.69-0.89). For HBe Ag-positive patients,the FIB-4 index was higher in CVR patients than in PVR patients at baseline(1.89 ± 1.43 vs 1.18 ± 0.69,P 0.001). There was no significant difference in the reduction of the FIB-4 index between the CVR and PVR groups from weeks 48 to 144(-0.11 ± 0.47 vs-0.13 ± 0.49,P = 0.71). At week 144,the FIB-4 index levels were similar between the two groups(1.24 ± 0.87 vs 1.02 ± 0.73,P = 0.06). After multivariate logistic regression analysis,a lower baseline serum HBV DNA level was associated with improvement of liver fibrosis. In HBe Ag-negative patients,the FIB-4 index did not differ between the two groups.CONCLUSION: The cumulative probabilities of HBV DNA responses showed significant differences between CVR and PVR HBe Ag-positive CHB patients undergoing entecavir treatment for 144 wk. However,long-term low-level HBV DNA did not deteriorate the FIB-4 index,which was used to evaluate liver fibrosis,at the end of three years.     

Comparison of 48‐week efficacy of tenofovir vs entecavir for patients with chronic hepatitis B: A network meta‐analysis

Both tenofovir disoproxil fumarate (TDF) and entecavir (ETV) are accepted as first‐line treatments for chronic hepatitis B (CHB). However, there are few randomized studies comparing their efficacy. The primary aim of this study was to compare the efficacy of TDF and ETV using a network meta‐analysis of randomized trials. The secondary aim was to additionally include propensity‐matched cohort studies in a conventional meta‐analysis. We systematically searched PubMed, EMBASE, Cochrane Library and Web of Science for published English‐language randomized and propensity‐matched studies between 1/1/2000 and 4/2/2020. Outcomes included undetectable HBV DNA, ALT normalization and HBeAg seroconversion at 48 weeks. We excluded patients who had co‐infection or significant prior treatment with antivirals. 13 517 participants from 16 studies (11 RCTs, n = 2675; five propensity‐matched cohort studies, n = 10 842) were included. Virological response at 48 weeks was higher in patients receiving TDF compared to ETV using both the network meta‐analytic approach (OR 1.69, P < .001) and the conventional meta‐analysis including propensity‐matched cohort studies (OR 1.40, P < .001). On subgroup analysis, this difference was only significant in HBeAg‐positive patients (OR 1.81, P = .037). There was limited evidence to suggest a higher rate of ALT normalization with ETV (OR 0.74, P = .07). There was no difference in rates of HBeAg seroconversion between the two antivirals. TDF is more likely than ETV to induce virological response at 48 weeks in treatment‐naïve CHB patients. Future studies should focus on elucidating associations between early and sustained virological response with adverse patient outcomes including development of HCC or cirrhosis.     

恩替卡韦治疗慢性HBV感染者KIR基因多态性与疗效的相关性研究

目的探讨慢性HBV感染者杀伤细胞免疫球蛋白样受体(killer immunoglobulin-like receptor,KIR)基因多态性及其与应用恩替卡韦疗效差异相关性。方法采用序列特异性引物聚合酶链反应(PCR-SSP)法,对60例应用恩替卡韦治疗的慢性HBV感染者(试验组)和60例健康对照者(对照组)的KIR基因进行基因分析,比较试验组和对照组的差异。60例患者中18例为治疗完全应答者(完全应答组),42例为非完全应答者(非完全应答组),比较2组之间差异。结果通过试验组和对照组的16种KIR基因分析,框架基因KIR2DL4、3DL2、3DL3和3DP1存在于所有个体中,其基因频率均为1.0。试验组KIR 2DS2和KIR2DS3基因型频率高于对照组(P值依次为0.038和0.035);完全应答组KIR2DS1、KIR3DS1和KIR2DL5基因型频率高于非完全应答组(P值依次为0.010、0.029和0.018)。结论 KIR2DS2、KIR2DS3可能是HBV的易感基因型,KIR2DS1、KIR3DS1、KIR2DL5可能与恩替卡韦抗HBV治疗有效应答有关。     

Randomized prospective study showing the non‐inferiority of tenofovir to entecavir in treatment‐naïve chronic hepatitis B patients

Aim

The study aimed to evaluate the efficacy and safety of tenofovir disoproxil fumarate (TDF) and entecavir hydrate (ETV) in nucleos(t)ide analog (NA)‐naïve Japanese chronic hepatitis B (CHB) patients.

Methods

This multicenter, randomized, double‐blinded study assessing the efficacy and safety of TDF 300 mg and ETV 0.5 mg in NA‐naïve CHB subjects was carried out from November 2011 to November 2014, and funded by GlaxoSmithKline. The subjects were assigned to the TDF arm or ETV arm in a 2:1 ratio. The primary efficacy endpoint was the non‐inferiority of TDF to ETV at week 24.

Results

A total of 166 subjects (TDF arm, 110; ETV arm, 56) were enrolled. The change (mean ± SE) in serum hepatitis B virus (HBV)‐DNA levels from baseline to week 24 was ?4.63 ± 0.044 and ?4.50 ± 0.063 log₁₀ copies/mL in the TDF and ETV arms, respectively, indicating the non‐inferiority of TDF to ETV (P < 0.0001). The proportion of subjects with undetectable HBV‐DNA increased from 54 to 77% and 39 to 66% in the TDF and ETV arms with continuation of the treatment from week 24 to 48, respectively. Reduction in hepatitis B surface antigen level was greater in subjects with hepatitis B envelope antigen (+) and high alanine aminotransferase levels (≥80 IU/L). Prevalence of drug‐related adverse events at week 48 was 20% and 18% in the TDF and ETV arms, respectively.

Conclusions

The study is the first to report that TDF has non‐inferiority to ETV in treatment effectiveness (lowering of serum HBV‐DNA level) at week 24. ClinicalTrials.gov trial registration nos. NCT01480284 and GSK LOC115409.     

Long‐term entecavir or tenofovir disoproxil fumarate therapy in treatment‐naïve chronic hepatitis B patients in the real‐world setting

The aim of this study was to determine the long‐term efficacy of entecavir (ETV) and tenofovir disoproxil fumarate (TDF) on the natural course of disease in chronic hepatitis B patients (CHB) with/without cirrhosis in clinical practice. A total of 355 treatment‐naïve CHB patients were enrolled into the study. The primary outcome measure was viral suppression as defined by serum HBV DNA level <20 IU/mL. A secondary outcome measure was to determine the development of Hepatocellular carcinoma (HCC). Virological and biochemical responses were similar between the two treatment groups over time. The presence of cirrhosis and hepatitis B e antigen (HBeAg) positivity did not appear to impact viral suppression. The cumulative probability of HBeAg loss was 41% at 4 years of therapy. Hepatitis B surface antigen (HBsAg) loss occurred in four patients. Model for End‐Stage Liver Disease score was significantly improved from baseline to week 48 and 96 under antiviral therapy (P = 0.013, P = 0.01). HCC was diagnosed in 17 patients (4.8%). The cumulative probability of the development of HCC was 3.3% at 1 year and 7.3% at 4 years of therapy. The development of HCC was independently associated with older age (P = 0.031) and the presence of cirrhosis (P = 0.004). Serum creatinine levels and creatinine clearance remained stable over time. ETV and TDF effectively maintained virological and biochemical responses in long‐term follow‐up of CHB patients with/without cirrhosis. HCC may still develop, although at a lower rate, and is more likely to develop in patients with cirrhosis, especially in older patients.