Changes in Renal Function in Patients With Chronic HBV Infection Treated With Tenofovir Disoproxil Fumarate vs Entecavir

Natural History and Prognosis of Chronic Hepatitis B Patients in the Indeterminate Phase

BACKGROUND AND AIMS

In chronic hepatitis B (CHB), an indeterminate phase exists outside the typical predefined phases. Our study investigates this indeterminate phase's natural history and prognosis, focusing on antiviral treatment outcomes.

METHODS

We conducted a retrospective cohort study to compare the risk of transitioning to immune active phase between inactive and indeterminate CHB and the incidence of hepatocellular carcinoma (HCC) and cirrhosis between untreated patients with indeterminate CHB (at baseline and throughout follow-up) and those who received treatment, following standard AASLD 2018 guidance.

RESULTS

The risk of transitioning to the immune active phase over 3, 5, and 10 years was 6.3%, 8.9%, and 14.2%, respectively, for inactive phase patients (n = 104). For HBeAg-negative indeterminate phase patients (n = 194), the risk was significantly higher at 23.0%, 31.9%, and 38.2%, and for HBeAg-positive indeterminate phase patients (n = 140), it was 40.4%, 52.0%, and 55.0% (p < 0.001). Inverse probability of treatment weighting (IPTW) was utilized to balance the groups of treated and untreated indeterminate patients. Following IPTW adjustment, the Kaplan-Meier curve analysis indicates that the risk of HCC and cirrhosis among untreated patients (n = 294) is higher than that among treated patients (n = 76), (p = 0.015 and 0.007, respectively). In the multivariable analysis, antiviral therapy remained an independent predictor of a reduced risk of HCC (aHR 0.128, 95% CI 0.031-0.522, p = 0.005) and cirrhosis (aHR 0.148, 95% CI 0.044-0.496, p = 0.002).

CONCLUSION

The indeterminate phase patients had a high-risk transition to active phase, and antiviral therapy can reduce the incidence of developing HCC and cirrhosis.

Effect of Entecavir, Tenofovir Disoproxil Fumarate, and Tenofovir Alafenamideantiviral Therapy on Renal Function in Chronic Hepatitis B Patients: A Real-World Retrospective Study

Background

Entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide(TAF) are first-line nucleos(t)ide analogs (NUCs) with chronic hepatitis B (CHB). This study aimed to assess the renal safety profile in NUC-experienced CHB patients who received ETV, TDF or TAF therapy.

Methods

This retrospective observational cohort study investigated factors related to renal function in 154 patients with NUC-experienced CHB who received ETV, TDF, and TAF therapy for 48 weeks. Changes in UREA, uric acid (UA), creatinine (Cr), and estimated glomerular filtration rate (eGFR) were analyzed using a one-way analysis of variance. A linear mixed-effects model for repeated measures was used to evaluate the correlation between baseline information and eGFR changes 48 weeks following treatment initiation. The model considered sex, baseline age, viral load, aminotransferases, renal function, and treatment group as fixed effects, and incorporated random effects for individual subjects.

Results

There were no significant differences in UA or Cr levels during therapy over time. The eGFR level was elevated in ETV-treated patients (117.5 ± 16.65 mL/min/1.7m2 vs 109.8 ± 15.69 mL/min/1.7m2, P=0.027), whereas it did not change significantly in TDF- (123.6 ± 28.54 mL/min/1.7m2 vs 115.5 ± 20.44 mL/min/1.7m2, P=0.070) and TAF-treated (121.6 ± 23.44 mL/min/1.7m2 vs 113.4 ± 16.90 mL/min/1.7m2, P=0.053) patients. Younger patients (<30 years) and those with higher HBV DNA (> 7 log10IU/mL) and lower alanine aminotransferase levels (<5 × upper limit of normal) showed a significant improvement in eGFR elevation during NUCs therapy. The linear mixed-effects model showed that the baseline HBV DNA level was an important positive predictor of eGFR elevation at 48 weeks following treatment initiation (estimate was 1.437 and 2.449, P<0.001).

Conclusion

In real-life experience, ETV, TDF, and TAF therapy may not be associated with eGFR changes in NUC-experienced CHB patients without baseline renal impairment.

Tenofovir versus entecavir on the prognosis of hepatitis B virus-related hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

Tenofovir (TDF) and entecavir (ETV) are first-line treatments for patients with chronic hepatitis B virus (HBV) infection. However, the effect of TDF versus ETV on the prognosis of HBV-related hepatocellular carcinoma (HCC) has not been fully clarified yet.

RESEARCH DESIGN AND METHODS

PubMed, Embase and Web of science were searched up to March, 2021. Meta-analyses were performed for overall survival (OS), disease-free survival (DFS) and recurrence-free survival (RFS) to assess the effect of TDF versus ETV on the prognosis of HBV-related HCC.

RESULTS

A total of 10 studies comprising 4706 Asian patients were included. The pooled results revealed that TDF was associated with better OS (adjusted HR=0.50, 95% CI: 0.40-0.62; I²=36.0%, p=0.167) and better RFS/DFS (adjusted HR=0.70, 95% CI: 0.55-0.89, I²=71.9%, p=0.002) than ETV in treatment of HBV-related HCC. Subgroup analysis revealed that OS benefit from TDF was generally consistent, except for patients who underwent non-surgical treatment for HCC. Subgroup analysis also indicated that TDF reduces the risk of late recurrence (HR=0.41, 95% CI: 0.18-0.0.93; I²=63.0%, p=0.067) rather than early recurrence (HR=0.99, 95% CI: 0.64-1.52; I²=61.3%, p=0.076).

CONCLUSIONS

Compared with ETV, TDF has the advantage of improving OS and reducing late recurrence of patients with HBV-related HCC patients who underwent resection.

Prophylactic tenofovir alafenamide for hepatitis B virus reactivation and reactivation-related hepatitis

No prospective study on the efficacy of tenofovir alafenamide (TAF), a novel tenofovir prodrug, in preventing hepatitis B virus (HBV) reactivation has yet been reported. This multicenter prospective study enrolled HBV-carriers who received TAF to prevent HBV reactivation before antitumor or immunosuppressive therapy, and patients with resolved HBV infection who experienced HBV-reactivation and received TAF to prevent HBV reactivation-related hepatitis. The efficacy of prophylactic TAF in preventing HBV reactivation and HBV reactivation-related hepatitis was evaluated at 6 and 12 months after initiating TAF. Overall, 110 patients were administered TAF to prevent HBV reactivation or HBV reactivation-related hepatitis. Three patients died owing to primary disease, whereas one patient was transferred to another hospital within 6 months after initiating TAF. Seven patients died due to primary disease, and five patients were transferred to another hospital within 12 months after initiating TAF. Therefore, 106 and 94 (77 patients with HBV infection, 17 with previous-HBV infection) patients were evaluated at 6 and 12 months after initiating TAF, respectively. No patient experienced HBV reactivation, HBV reactivation-related hepatitis, or treatment discontinuation due to HBV reactivation or adverse events of TAF after 6 and 12 months. TAF could effectively prevent HBV reactivation and HBV reactivation-related hepatitis.

Effect of pegylated interferon-α2b add-on therapy on renal function in chronic hepatitis B patients: A real-world experience

BACKGROUND AND AIM

Controversy remains as to pegylated interferon-α (PEG-IFNα) antiviral therapy to renal function in chronic hepatitis B (CHB) patients. The aim of this study was to evaluate the influence of PEG-IFNα2b (Y shape, 40 kD) add-on treatment for renal function in CHB patients who received entecavir therapy.

METHODS

This was a retrospective observational study to investigate factors related to renal function in 114 CHB patients who received PEG-IFNα2b add-on therapy to entecavir for 48 weeks. Changes of blood urea nitrogen (BUN), serum creatinine (sCr), and estimated glomerular filtration rate (eGFR), which was calculated with both Chronic Kidney Disease Epidemiology Collaboration and Modification of Diet in Renal Disease (MDRD) formulas, were analyzed by one-way analysis of variance. A linear mixed effects model for repeated measures was used to assess the correlation between baseline information and eGFR changes at 24 and 48 weeks of therapy. The model considered the baseline age, gender, body weight, viral load, hepatitis B surface antigen, BUN, sCr, and treatment strategy as fixed effects and incorporated random effects for individual subjects.

RESULTS

BUN and sCr was decreased, while eGFR was increased at 12 weeks of therapy. Only eGFR maintained at 24 and 48 weeks of therapy. Patients with female gender, age ≥ 40 years, and baseline HBsAg level < 250 IU/mL showed significant improvement of renal function with PEG-IFNα2b add-on therapy. The linear mixed effects model revealed that female gender, baseline sCr, and PEG-IFNα2b add-on were significant positive predictors for eGFR elevation at 24 and 48 weeks of therapy.

CONCLUSION

In real-world experience, PEG-IFNα2b add-on therapy might be associated with increased eGFR in CHB patients.

Higher risk of kidney function decline with entecavir than tenofovir alafenamide in patients with chronic hepatitis B

BACKGROUND AND AIMS

Entecavir (ETV) and tenofovir alafenamide (TAF) are the preferred agents in patients with predisposing factors for nephrotoxicity, but no studies to date have directly compared the renal safety of the two antiviral agents. Hence, we compared the risk of kidney function decline among patients with treatment-naïve chronic hepatitis B (CHB) treated with ETV or TAF.

METHODS

This study included 1988 patients with treatment-naïve CHB who were treated with ETV (n = 1839) or TAF (n = 149) between 2007 and 2020 for ETV and between 2017 and 2020 for TAF. The primary outcome was chronic kidney disease (CKD) progression, defined as an increase in CKD stage by at least one stage for at least three consecutive months.

RESULTS

A 1:1 propensity score match yielded 149 patients in each treatment group. The mean estimated glomerular filtration rate (eGFR) was 100.6 ml/min/1.73 m2 vs. 101.3 ml/min/1.73 m2 in the ETV and TAF groups respectively. A total of 61 patients developed a progression in CKD stage ≥ 1, of which 47 and 14 patients were from the ETV- and TAF-treated groups respectively (19.9 vs. 5.1 per 1000 person-years; p < .001). The risk of progression in CKD stage ≥1 was significantly higher in patients treated with ETV, even when adjusted for potential confounders (adjusted hazard ratio 4.05; 95% CI 2.14-7.68; p < .001).

CONCLUSIONS

ETV was associated with a higher risk of kidney function decline than TAF in patients with treatment-naïve CHB. Therefore, further prospective randomized studies are needed.

Tenofovir is Associated With Higher Risk of Kidney Function Decline Than Entecavir in Patients With Chronic Hepatitis B

Of the antiviral agents currently available to patients with chronic hepatitis B (CHB), entecavir (ETV) and tenofovir disoproxil fumarate (TDF) are 2 of 3 first-line agents.1-3 Given the well-known renal and bone toxicity associated with TDF,4 major international hepatitis B virus treatment guidelines recommend ETV over TDF in patients with predisposing factors to kidney function decline.1-3 However, as evidenced by recent studies, nephrotoxicity of antiviral agents is still an issue under debate.5-7 Therefore, we investigated the differences in the risk of kidney function decline in patients with treatment-naive CHB who were treated with ETV or TDF.

Longitudinal renal changes in chronic hepatitis B patients treated with entecavir versus TDF: a REAL-B study

BACKGROUND AND AIMS

We aimed to compare the longitudinal changes in estimated glomerular filtration rate (eGFR) in chronic hepatitis B (CHB) patients treated with entecavir (ETV) vs. tenofovir disoproxil fumarate (TDF).

METHODS

This is a retrospective study of 6189 adult treatment-naïve CHB patients initiated therapy with TDF (n = 2482) or ETV (n = 3707) at 25 international centers using multivariable generalized linear modeling (GLM) to determine mean eGFR (mL/min/1.73 m2) and Kaplan-Meier method to estimate incidence of renal impairment (≥ 1 chronic kidney disease [CKD] stage worsening). We also examined above renal changes in matched ETV and TDF patients (via propensity score matching [PSM] on age, sex, diabetes mellitus [DM], hypertension [HTN], cirrhosis, baseline eGFR, and follow-up duration).

RESULTS

In the overall cohort (mean age 49.7 years, 66.2% male), the baseline eGFR was higher for TDF vs. ETV group (75.9 vs. 74.0, p = 0.009). PSM yielded 1871 pairs of ETV or TDF patients with baseline eGFR ≥ 60 and 520 pairs for the eGFR < 60 group. GLM analysis of the overall (unmatched) cohort and PSM cohorts revealed lower adjusted mean eGFRs in TDF (vs. ETV) patients (all p < 0.01) during 10 years of follow-up. Among PSM eGFR ≥ 60 patients, the 5-year cumulative incidences of renal impairment were 42.64% for ETV and 48.03% for TDF (p = 0.0023). In multivariable Cox regression, TDF vs. ETV (adjusted HR 1.26, 95% CI 1.11-1.43) was associated with higher risk of worsening renal function.

CONCLUSION

Over the 10-year study follow-up, compared to ETV, TDF was associated with a lower mean eGFR and higher incidence of renal impairment.

Comparison of Tenofovir Alafenamide and Entecavir Therapy in Patients with Chronic Hepatitis B Initially Treated with Tenofovir Disoproxil: A Retrospective Observational Survey

Background: In chronic hepatitis B patients with or exposed to the risk of osteoporosis or renal dysfunction, switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide fumarate (TAF) or entecavir (ETV) may be the right choice. Objectives: This study aimed to present real-life data in terms of the efficacy and safety of a TAF/ETV treatment change while receiving TDF. Methods: This retrospective study was conducted on 344 adult patients from 10 centers. The data of patients who had changed to ETV (n = 107) and TAF (n = 237) while receiving TDF were analyzed. The data collected at 0 and 6 months of treatment were analyzed. The virological response was assessed based on undetected hepatitis B virus (HBV) DNA. Serum alanine aminotransferase (ALT) values were used to evaluate the biochemical response. For renal function, serum creatinine and phosphorus, as well as estimated glomerular filtration rate (eGFR), were recorded. Moreover, lumbar spine and hip T-scores along with the serum lipid profile were evaluated. Results: The mean age of patients was 41.14 ± 13.46 years, and 224 (65.1%) of the participants were male. The treatment arms were not significantly different in terms of demographic characteristics, comorbid diseases, infection duration, family history of HBV infection, blood platelet count, serum biomarkers, such as ALT, phosphorus, creatinine, total bilirubin, albumin, lipid profile, and HBV DNA levels at the beginning. No statistically significant difference was found between the proportion of undetectable HBV DNA of the two treatment groups after 6 months (P = 0.221). The ALT normalization in the ETV and TAF groups at the sixth month compared to the baseline levels was not significantly different (P = 0.853, P = 0.330, respectively). There was no statistically significant difference between the two treatment arms regarding changes in eGFR, creatinine, phosphorus, hip, and spine T-scores from baseline to 6 months (P = 0.296, P = 0.78, P = 0.141, P = 0.832, P = 0.947, respectively). In those who switched to TAF or ETV, low-density lipoproteins cholesterol were observed to be significantly higher after 6 months compared to baseline values (P = 0.002, P = 0.049, respectively). The TC increased significantly in the TAF group (P = 0.035). Conclusions: Our study showed that switching to ETV and TAF sustained the viral suppression and biochemical response achieved by TDF therapy. The treatment switch to TAF of ETV can control renal dysfunction and reduce bone mineral density caused by TDF.

Real-World Single-Center Comparison of the Safety and Efficacy of Entecavir, Tenofovir Disoproxil Fumarate, and Tenofovir Alafenamide in Patients with Chronic Hepatitis B

INTRODUCTION

Chronic hepatitis B (CHB) is a major cause of chronic liver diseases and tenofovir disoproxil fumarate (TDF), tenofovir alafenamide (TAF), and entecavir (ETV) are recommended as primary treatments. This study aimed to evaluate the efficacy and safety of ETV, TDF, and TAF in a real-world clinical setting.

METHODS

In this retrospective cohort study, a total of 363 CHB patients who were treated with ETV (n = 163), TDF (n = 154), or TAF (n = 46) from July 2007 to September 2019 were enrolled.

RESULTS

Median patient age was 51 years and 66.4% of patients were male. Median duration of treatment with ETV, TDF, or TAF was 49.0 months (interquartile range, 27.0-74.0 months). In terms of safety, cholesterol was mildly increased in the ETV and TAF groups and significantly lowered in the TDF group than baseline (p < 0.001). There was no significant difference in liver cirrhosis-related complications among the 3 groups at 48 weeks (p = 0.235). Hepatitis B e antigen seroconversion, complete virological response, and alanine aminotransferase normalization at 48 weeks as measures of treatment efficacy were not significantly different among the 3 groups (p = 0.142, 0.538, and 0.520, respectively). There was also no significant difference in cumulative incidence rate of hepatocellular carcinoma (HCC) between the ETV and TDF groups (p = 0.894).

CONCLUSIONS

ETV, TDF, and TAF were safe antiviral agents and showed similar antiviral effect for CHB at 48 weeks. Cirrhosis-related complications and annual HCC incidence rates did not differ significantly between the ETV and TDF groups over the 48 week follow-up period.

Evaluating the renal safety of tenofovir disoproxil fumarate in hepatitis B patients without chronic kidney disease

The nephrotoxicity of tenofovir disoproxil fumarate (TDF) in chronic hepatitis B (CHB) patients without chronic kidney disease (CKD) remains controversial. We aimed to evaluate nephrotoxicity of TDF in this population. In this hospital-based cohort study, CHB patients who received either TDF or entecavir (ETV) therapy, and did not have underlying CKD, were retrospectively recruited from January, 2008 to January, 2019. After excluding those with confounding conditions, 257 TDF-treated patients were matched through propensity scores with 514 ETV-treated patients. Cumulative incidences of, and hazard ratios (HRs) for the CKD guideline-defined renal dysfunction, were analysed. The mean decline in glomerular filtration rate was similar over 60 months (TDF vs. ETV: 10.1 ml/min/1.73 m² , 95% confidence interval [CI]: 7.4-12.7 vs. 8.0 ml/min/1.73 m² , 95% CI: 6.4-9.6; p = .34). The 5-year cumulative incidence of renal dysfunction was not significantly different (TDF vs. ETV: 10.4%, 95% CI: 5.6-18.0 vs. 5.8%, 95% CI: 3.6-9.0; p = .18). However, in multivariable stratified analysis, TDF was associated with an increased risk of renal dysfunction in the elderly (age ≥60 years), when compared to ETV (HR 2.86, 95% CI: 1.02-8.01; p < .05). For confirming the effect of TDF amongst the elderly, 61 TDF-treated patients were further matched with 183 ETV-treated patients, with 5-year cumulative incidence of renal dysfunction being significantly higher in TDF users (TDF vs. ETV: 34.4%, 95% CI: 17.7-59.8 vs. 15.5%, 95% CI: 9.4-25.1; p < .05). TDF use was independently related to renal dysfunction (HR 2.71, 95% CI: 1.19-6.14; p < .05). Although TDF is generally safe for CHB patients without CKD, it is best to be avoided in the elderly.

Pharmacokinetics of Tenofovir Alafenamide Fumarate and Tenofovir in the Chinese People: Effects of Non-Genetic Factors and Genetic Variations

Background

Tenofovir alafenamide fumarate (TAF) was approved for HBV treatment in China in 2018. Despite higher antiviral efficacy and less impact on renal function and bone mineral density, the pharmacokinetic profiles of TAF are highly variable. The objectives of this study were to investigate the pharmacokinetics of TAF in the Chinese population and explore the associations between TAF and genetic polymorphisms and non-genetic factors.

Patients and Methods

A total of 64 healthy Chinese subjects aged 18~65 years old were planned to enroll. According to the dietary intake status, the subjects were divided into two groups (n = 32 per group). The concentrations of TAF and tenofovir were measured by HPLC-MS/MS, and the single-nucleotide polymorphisms were analyzed by MALDI-TOF MS.

Results

All the enrolled participants (18–35 years) completed the clinical trial study. Similar to the results reported in other ethnic populations, the pharmacokinetic profiles of TAF and tenofovir were highly variable in the Chinese people, and the HFHC diet can significantly increase the systemic exposure of TAF. We determined both HFHC diet and rs7311358 (SLCO1B3) genotypes were independently associated with TAF AUC_0-t, while HFHC diet, age and rs3740066 (ABCC2) variants were predictive of t_1/2 of tenofovir (P < 0.05). The subjects with the AA genotype in rs7311358 had significantly higher TAF AUC_0-t values (1.15 times) than those with a G allele, and the t_1/2 of tenofovir in the rs3740066 TT genotype group was 1.23 times longer than that of CC genotype group. Furthermore, there was a trend of higher TAF AUC and shorter tenofovir t_1/2 for the rs2032582 (ABCB1) T allele and rs3742106 (ABCC4) CC variant, respectively, although not statistically significant in the multiple linear regression analysis.

Conclusion

This study provided new evidence to suggest a critical link between both genetic and non-genetic factors and TAF pharmacokinetics in the Chinese people.

Treatment and Renal Outcomes Up to 96 Weeks After Tenofovir Alafenamide Switch From Tenofovir Disoproxil Fumarate in Routine Practice

BACKGROUND AND AIMS

Real-world data for treatment effectiveness and renal outcomes in chronic hepatitis B (CHB) patients who were switched to the new and safer prodrug tenofovir alafenamide (TAF) from tenofovir disoproxil fumarate (TDF) are limited. Therefore, we aimed to evaluate treatment and renal outcomes of this population.

APPROACH AND RESULTS

We analyzed 834 patients with CHB previously treated with TDF for ≥12 months who were switched to TAF in routine practice at 13 US and Asian centers for changes in viral (HBV DNA < 20 IU/mL), biochemical (alanine aminotransferase [ALT] < 35/25 U/L for male/female), and complete (viral+biochemical) responses, as well as estimated glomerular filtration rate (eGFR; milliliters per minute per 1.73 square meters) up to 96 weeks after switch. Viral suppression (P < 0.001) and ALT normalization (P = 0.003) rates increased significantly after switch, with a trend for increasing complete response (Ptrend = 0.004), while the eGFR trend (Ptrend  > 0.44) or mean eGFR (P > 0.83, adjusted for age, sex, baseline eGFR, and diabetes, hypertension, or cirrhosis by generalized linear modeling) remained stable. However, among those with baseline eGFR < 90 (chronic kidney disease [CKD] stage ≥2), mean eGFR decreased significantly while on TDF (P = 0.029) but not after TAF switch (P = 0.90). By week 96, 21% (55/267) of patients with CKD stage 2 at switch improved to stage 1 and 35% (30/85) of CKD stage 3-5 patients improved to stage 2 and 1.2% (1/85) to stage 1.

CONCLUSIONS

Overall, we observed continued improvement in virologic response, ALT normalization, and no significant changes in eGFR following switch to TAF from TDF.

3-year Treatment of Tenofovir Alafenamide vs. Tenofovir Disoproxil Fumarate for Chronic HBV Infection in China

BACKGROUND AND AIMS

Tenofovir alafenamide (TAF) has similar efficacy to tenofovir disoproxil fumarate (TDF) but with improved renal and bone safety in chronic hepatitis B patients studied outside of China. We report 3-year results from two phase 3 studies with TAF in China (Clinicaltrials.gov: NCT02836249 and NCT02836236).

METHODS

Chinese hepatitis B e antigen (HBeAg)-positive and -negative chronic hepatitis B patients with viremia and elevated alanine aminotransferase were randomized 2:1 to TAF or TDF treatment groups and treated in a double-blind fashion for 144 weeks (3 years). Efficacy responses were assessed by individual study while safety was assessed by a pooled analysis.

RESULTS

Of the 334 patients (180 HBeAg-positive and 154 HBeAg-negative) randomized and treated, baseline characteristics were similar between groups. The overall mean age was 38 years and 73% were male. The mean HBV DNA was 6.4 log₁₀ IU/mL. The median alanine aminotransferase was 88 U/L, and 37% had a history of antiviral use. At week 144, the proportion with HBV DNA <29 IU/mL was similar among the two groups, with TAF at 83% vs. TDF at 79%, and TAF at 93% vs. TDF at 92% for the HBeAg-positive and -negative patients, respectively. In each study, higher proportions of TAF than TDF patients showed normalized alanine aminotransferase (via the American Association for the Study of Liver Diseases and the China criteria) and showed loss of HBsAg; meanwhile, the HBeAg seroconversion rates were similar. Treatment was well-tolerated among the TAF patients, who showed a smaller median decline in creatinine clearance (-0.4 vs. -3.2 mL/min; p=0.014) and less percentage change in bone mineral density vs. TDF at hip (-0.95% vs. -1.93%) and spine (+0.35% vs. -1.40%).

CONCLUSIONS

In chronic hepatitis B patients from China, TAF treatment provided efficacy similar to TDF but with better renal and bone safety at 3 years.

Hepatitis B virus (HBV) viral load, liver and renal function in adults treated with tenofovir disoproxil fumarate (TDF) vs. untreated: a retrospective longitudinal UK cohort study

BACKGROUND

Current clinical guidelines recommend treating chronic hepatitis B virus (HBV) infection in a minority of cases, but there are relatively scarce data on evolution or progression of liver inflammation and fibrosis in cases of chronic HBV (CHB) that do not meet treatment criteria. We aimed to assess the impact of TDF on liver disease, and the risk of renal impairment in treated CHB patients in comparison to untreated patients.

METHODS

We studied a longitudinal ethnically diverse CHB cohort in the UK attending out-patient clinics between 2005 and 2018. We examined TDF treatment (vs. untreated) as the main exposure, with HBV DNA viral load (VL), ALT, elastography scores and eGFR as the main outcomes, using paired tests and mixed effects model for longitudinal measurements. Additionally, decline of eGFR during follow-up was quantified within individuals by thresholds based on clinical guidelines. Baseline was defined as treatment initiation for TDF group and the beginning of clinical follow-up for untreated group respectively.

RESULTS

We included 206 adults (60 on TDF, 146 untreated), with a median ± IQR follow-up duration of 3.3 ± 2.8 years. The TDF group was significantly older (median age 39 vs. 35 years, p = 0.004) and more likely to be male (63% vs. 47%, p = 0.04) compared to the untreated group. Baseline difference between TDF and untreated groups reflected treatment eligibility criteria. As expected, VL and ALT declined significantly over time in TDF-treated patients. Elastography scores normalised during treatment in the TDF group reflecting regression of inflammation and/or fibrosis. However, 6/81 (7.4%) of untreated patients had a progression of fibrosis stage from F0-F1 to F2 or F3. There was no evidence of difference in rates or incidence of renal impairment during follow-up in the TDF vs. untreated group.

CONCLUSIONS

Risk of liver inflammation and fibrosis may be raised in untreated patients compared to those receiving TDF, and TDF may benefit a larger percentage of the CHB population.

Outcomes of Sequential Therapy With Tenofovir Alafenamide After Long-term Entecavir

INTRODUCTION

Entecavir (ETV) and tenofovir alafenamide (TAF) are both first-line hepatitis B virus (HBV) therapies, but ETV-to-TAF switch outcome data are limited. We aimed to assess outcomes up to 96 weeks after ETV-to-TAF switch.

METHODS

ETV-treated (≥12 months) chronic hepatitis B patients switched to TAF in routine practice at 15 centers (United States, Korea, Japan, and Taiwan) were included. Primary outcome was complete viral suppression (CVS) rate (HBV DNA <20 IU/mL).

RESULTS

We analyzed 425 eligible patients (mean age 60.7 ± 13.2 years, 60% men, 90.8% Asian, 20.7% with diabetes, 27% with hypertension, 14.8% with cirrhosis, 8.3% with hepatocellular carcinoma, and mean ETV duration before switch 6.16 ± 3.17 years). The mean baseline estimated glomerular filtration rate (eGFR) was 89 ± 19 (chronic kidney disease [CKD] stages: 55.6% stage 1, 35.7% stage 2, and 8.8% stages 3-5). CVS rate increased from 91.90% at switch (from 90.46% 24 weeks before switch) to 95.57% and 97.21% at 48 and 96 weeks after (P = 0.03 and 0.02, respectively). Over the 96 weeks after switch, mean HBV DNA (P < 0.001) but not alanine aminotransferase or CKD stage decreased. Between switch and 96-week follow-up, 11% (26/235) of CKD stage 1 patients migrated to stage 2 and 8% (12/151) of stage 2 patients to stages 3-5, whereas 18% (27/151) from stage 2 to 1, and 19% (7/37) from stages 3-5 to 2. On multivariable generalized estimated equation analysis adjusted for age, sex, hypertension, diabetes, and cirrhosis, baseline eGFR, age (P < 0.001), and CKD stages 2 and 3-5 (vs 1) (both P < 0.001) were associated with lower follow-up eGFR.

DISCUSSION

After an average of 6 years on ETV, CVS increased from 91.9% at TAF switch to 97.2% at 96 weeks later.

Tenofovir Alafenamide Rescues Renal Tubules in Patients with Chronic Hepatitis B

Nucles(t)ide analogs (NAs) are effective for chronic hepatitis B (CHB). NAs suppress hepatic decompensation and hepatocarcinogenesis, leading to a dramatic improvement of the natural course of patients with CHB. However, renal dysfunction is becoming an important issue for the management of CHB. Renal dysfunction develops in patients with the long-term treatment of NAs including adefovir dipivoxil and tenofovir disoproxil fumarate. Recently, several studies have reported that the newly approved tenofovir alafenamide (TAF) has a safe profile for the kidney due to greater plasma stability. In this mini-review, we discuss the effectiveness of switching to TAF for NAs-related renal tubular dysfunction in patients with CHB.

Hepatocellular carcinoma incidence with tenofovir versus entecavir in chronic hepatitis B: a systematic review and meta-analysis

BACKGROUND

It is unclear whether tenofovir disoproxil fumarate and entecavir differ in their association with risk of hepatocellular carcinoma in patients with chronic hepatitis B, and previous meta-analyses have shown conflicting conclusions with substantial heterogeneity. We aimed to analyse the updated data and elucidate the source of heterogeneity.

METHODS

We searched PubMed, Embase, Web of Science, and the Cochrane library for relevant studies with time-to-event data for incident hepatocellular carcinoma occurring in patients with chronic hepatitis B who received tenofovir disoproxil fumarate or entecavir monotherapy with follow-up of at least 1 year. Studies published between Jan 1, 2006, and April 17, 2020, and abstracts from international conferences in 2018 and 2019 were included. We pooled covariate adjusted hazard ratios (HRs) for hepatocellular carcinoma using a random-effects model, assessed heterogeneity among included studies using the I2 statistic and Cochran's Q test, and identified the source of heterogeneity using prespecified subgroup analyses. This study is registered with PROSPERO, ID CRD42020176513.

FINDINGS

31 studies involving 119 053 patients were analysed. The 5-year cumulative incidence of hepatocellular carcinoma was 5·97% (95% CI 5·81-6·13, 28 studies) for entecavir and 3·06% (2·86-3·26, 13 studies) for tenofovir disoproxil fumarate in studies with unmatched populations (p<0·0001). For all eight studies matched by propensity score, the 5-year cumulative incidence was 3·44% (95% CI 3·08-3·80) for entecavir and 3·39% (2·94-3·83) for tenofovir disoproxil fumarate (p=0·87). Analysis of 14 comparative studies with covariate adjustment found that tenofovir disoproxil fumarate and entecavir had similar risk of hepatocellular carcinoma (primary outcome); adjusted HR 0·88, 95% CI 0·73-1·07; p=0·20), although heterogeneity was significant (I2=56·4%, p=0·0038). In a subgroup analysis for hospital-based clinical cohorts, there was no difference in hepatocellular carcinoma incidence between the two regimens (adjusted HR 1·03, 95% CI 0·88-1·21; I2=0%). However, tenofovir disoproxil fumarate was associated with a lower risk of hepatocellular carcinoma compared with entecavir in administrative database research (adjusted HR 0·67, 0·59-0·76; I2=0%).

INTERPRETATION

Our study found no significant difference between tenofovir disoproxil fumarate and entecavir in their association with incident hepatocellular carcinoma. We suggest that treatment should be guided by patient tolerability and affordability rather than whether one drug is more effective than the other.

FUNDING

Supported in part by E-DA Hospital (EDAHP 106008; EDAHP 103046).

Increasing Age and Nonliver Comorbidities in Patients with Chronic Hepatitis B in Taiwan: A Nationwide Population-Based Analysis

BACKGROUND

Data from the USA suggest that chronic hepatitis B (CHB) patients have aged in the past decade. However, the burden of nonliver comorbidities has not been well characterized in Taiwan, where CHB is very prevalent.

AIM

Our study examined this issue as it presented between 2001 and 2011 in Taiwan.

METHODS

This study identified adult patients (≥18 years) who were diagnosed with CHB in 2001, 2006, and 2011, from the Taiwan National Health Insurance Research Database (NHIRD). Changes in demographic characteristics, prevalence of nonliver comorbidities, and medication usage over the decade were examined. Non-CHB controls were adults without CHB diagnosis from the Longitudinal Health Insurance Database 2000 (LHID2000).

RESULTS

A total of 102,158, 252,809, and 338,200 eligible patients were identified in 2001, 2006, and 2011, respectively. The mean age significantly advanced from 45.4 to 52.3 years over the decade (p < 0.001). The prevalence of comorbidities, including diabetes mellitus, hypertension, stroke, chronic kidney disease, and bone fracture, significantly increased between 2001 and 2011 (all p < 0.001), as so were medication usage (all p < 0.001). Moreover, within each study period, compared to non-CHB controls, CHB patients were also older and more likely to have metabolic and cardiovascular comorbidities (all p < 0.001). In addition, the annual nonliver mortality in the CHB population significantly increased from 2001 to 2011.

CONCLUSIONS

Over a decade, the CHB population in Taiwan has aged with a higher nonliver comorbidity burden and increasing nonliver mortality. These findings may provide information to care providers in the monitoring and management of CHB patients.

Editorial: tenofovir disoproxil fumarate vs entecavir in patients with chronic hepatitis B and renal impairment-still an open issue

LINKED CONTENT

This article is linked to Lampertico et al paper. To view this article, visit https://doi.org/10.1111/apt.15901

Association between liver cirrhosis and estimated glomerular filtration rates in patients with chronic HBV infection

To investigate the estimated glomerular filtration rates of chronic hepatitis B (CHB) patients with or without liver cirrhosis, and to explore the related risk factors.A total of 559 CHB patients were enrolled. Liver cirrhosis was diagnosed with ultrasound. The Child-Pugh scoring system was used to stage patients with liver cirrhosis. The Modification of Diet in Renal Disease (MDRD) formula was used to calculate the estimated glomerular filtration rate (eGFR).A total of 296 patients were involved. The results showed that the incidence of renal impairment in patients with liver cirrhosis was 8.45% (25/296). The incidence of renal impairment in Child-Pugh C patients was significantly higher than that in Child-Pugh B and Child-Pugh Grade A patients (i.e., 17.2% [17/99] vs 6.67% [7/105] vs 1.09% [1/92], respectively, P < .001); age, hyperuricemia, and Child-Pugh score are all risk factors for impaired renal function.With the deterioration of liver function in patients with cirrhosis, the incidence of impaired renal function has increased significantly, and renal function should be closely monitored to guide patients in clinical medication.

Consensus document of the Spanish Association for Study of the Liver on the treatment of hepatitis B virus infection (2020)

Hepatitis B virus (HBV) infection remains a global public health problem. HBV vaccination is the most effective tool to reduce the incidence of HBV disease. Despite there has not been new clinical developments for the treatment of chronic hepatitis B in the last few years, changing epidemiology and current insights on natural history, diagnostic tools and therapy indications make necessary an update of the former version of the consensus document of the Spanish Association for Study of the Liver on the treatment of hepatitis B infection published in 2012. The current document updates the management of chronic hepatitis B. The treatment of choice is the long-term administration of a nucleos(t)ide analogue with high barrier to resistance (entecavir, tenofovir or tenofovir alafenamide). Pegylated interferon may be an option in patients with non-advanced liver disease, but its applicability is limited due to the low efficacy and poor tolerability. All patients must be monitored for the risk of progression to advanced liver disease and development of hepatocellular carcinoma.

Association between serum Cystatin C and renal injury in patients with chronic hepatitis B

To explore the association between serum cystatin C (Cys-C) and renal damage in patients with chronic hepatitis B.We retrospectively analyzed the clinical data of 425 patients with chronic hepatitis B virus (HBV) infection. Liver stiffness measured by FibroScan was used to diagnosis liver fibrosis. Cys-C levels were detected via latex-enhanced immunoturbidimetric assay.A total of 425 patients were enrolled. Among them, 217 were patients with CHB with an eGFR > 90 mL/min/1.73 m and 208 with an eGFR ≤90 mL/min/1.73 m. Cys-C levels significantly differed in patients with eGFR > 90 mL/min/1.73 m compared with patients with eGFR ≤90 mL/min/1.73 m (0.81 ± 0.05 vs 1.05 ± 0.06 mg/L, P < .001). Moreover, the Cys-C levels were 0.82 ± 0.04 mg/L in patients without liver fibrosis, 0.98 ± 0.05 mg/L in patients with mild liver fibrosis, 1.05 ± 0.08 mg/L in patients with advanced liver fibrosis, and 1.12 ± 0.07 mg/L in patients with liver cirrhosis (P < .001). Multivariate analyses were conducted to explore the independent factors associated with a decreased eGFR. Multivariate analysis suggested that T2DM (P = .032), liver fibrosis (P = .013), and Cys-C level (P = .035) were the independent factors associated with the decreased eGFR in patients with CHB. While age (P = .020) and Cys-C level (P = .001) were the independent factors associated with the decreased eGFR in patients with CHB-related fibrosis.The fibrosis group had significantly higher Cys-C levels than those without fibrosis. Routine monitoring of Cys-C levels is of positive significance in preventing the development of renal impairment of CHB patients.

Treatment with tenofovir disoproxil fumarate or entecavir in chronic hepatitis B virus-infected patients with renal impairment: results from a 7-year, multicentre retrospective cohort study

BACKGROUND

Limited data exist regarding tenofovir disoproxil fumarate (TDF) safety and effectiveness in chronic hepatitis B virus-infected (CHB) patients with renal impairment (RI).

AIMS

To compare real-world data on renal safety and effectiveness of TDF vs entecavir (ETV) in CHB patients with moderate-to-severe RI.

METHODS

Retrospective, non-interventional, cohort study analysing medical records for TDF/ETV-treated CHB patients (54 European centres). Included patients experienced moderate-to-severe RI (creatinine clearance 20-60 mL/min [Cockcroft-Gault]) either before TDF/ETV initiation ('before' subgroup [baseline = treatment initiation]) or after TDF/ETV initiation ('after' subgroup [baseline = first RI occurrence]). The primary objective was TDF safety, particularly renal-related adverse events of special interest (AESI). TDF and ETV safety and effectiveness were compared and multivariate analyses were performed using inverse probability treatment weighting.

RESULTS

'Before' subgroup included 107 TDF- and 91 ETV-treated patients; 'after' subgroup included 212 TDF- and 77 ETV-treated patients. Mean baseline creatinine clearance was higher for TDF- vs ETV-treated patients (both subgroups). Median follow-up was 3.1 years (both treatments). AESI were more frequent with TDF vs ETV ('before': 18.7% vs 8.8%; 'after': 9.9% vs 3.9%); however, differences were not significant by multivariate analysis. Only TDF-treated patients experienced renal tubular dysfunction (6.5% 'before'; 1.9% 'after') as well as renal adverse events leading to treatment discontinuation (8.4% 'before'; 7.1% 'after'). Effectiveness was similar between treatments.

CONCLUSIONS

Overall safety was similar for TDF vs ETV (both subgroups). Given that renal tubular dysfunction occurred with TDF and not with ETV, renal safety concerns may be greater with TDF in CHB patients with RI.

An observational study on long-term renal outcome in patients with chronic hepatitis B treated with tenofovir disoproxil fumarate

In patients with chronic hepatitis B (CHB), long-term effects of tenofovir disoproxil fumarate (TDF) on renal function have been controversial. This study aimed to analyse the real-world long-term effects of TDF on renal function in Korean patients with CHB. We analysed a cohort of 640 treatment-naïve patients with CHB who were treated with TDF between May 2012 and December 2015 at Severance Hospital, Seoul, Republic of Korea. The mean age was 48.3 years old, and 59.5% were male. The proportions of hypertension and diabetes mellitus (DM) were 11.6% and 14.2%, respectively, and that of liver cirrhosis was 20.8%. During the 5-year follow-up, using a linear mixed model, serum creatinine increased from 0.77 ± 0.01 mg/dL to 0.85 ± 0.02 mg/dL (P < .001), and eGFR decreased from 102.6 ± 0.6 mL/min/1.73 m2 to 93.4 ± 1.4 mL/min/1.73 m2 (P < .001). In subgroup analysis, eGFR was statistically more decreased in patients with age > 60 than ≦60 years old (P = .027), and in patients with diuretic use than without diuretic use (P = .008). In multivariate analysis, the independent risk factors for eGFR decrease > 20% were baseline eGFR < 60mL/min/1.73 m2 (P = .034) and the use of diuretics (P < .001). CHB patients on TDF experienced greater reduction in renal function with age > 60 and with diuretic use compared to those without these characteristics. Baseline eGFR < 60 mL/min/1.73 m2 and use of diuretics were independent risk factors of eGFR decline of more than 20% on TDF therapy.

Tenofovir Versus Entecavir for Hepatocellular Carcinoma Prevention in an International Consortium of Chronic Hepatitis B

INTRODUCTION

It is unclear whether entecavir (ETV) and tenofovir disoproxil fumarate (TDF) differ in their effectiveness for preventing hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB).

METHODS

This retrospective cohort study analyzed an international consortium that encompassed 19 centers from 6 countries or regions composed of previously untreated CHB patients then treated with either ETV or TDF monotherapy. Those who developed HCC before antiviral treatment or within 1 year of therapy were excluded. The association between antiviral regimen and HCC risk was evaluated using competing-risk survival regression. We also applied propensity score matching (PSM) to 1:1 balance the 2 treatment cohorts. A total of 5,537 patients were eligible (n = 4,837 received ETV and n = 700 received TDF) and observed for HCC occurrence until December 23, 2018. Before PSM, the TDF cohort was significantly younger and had generally less advanced diseases.

RESULTS

In the unadjusted analysis, TDF was associated with a lower risk of HCC (subdistribution hazard ratio [SHR], 0.45; 95% confidence interval [CI], 0.26-0.79; P = 0.005). The multivariable analysis, however, found that the association between TDF and HCC no longer existed (SHR, 0.81; 95% CI, 0.42-1.56; P = 0.52) after adjustment for age, sex, country, albumin, platelet, α-fetoprotein, cirrhosis, and diabetes mellitus. Furthermore, the PSM analysis (n = 1,040) found no between-cohort differences in HCC incidences (P = 0.51) and no association between regimens (TDF or ETV) and HCC risk in the multivariable-adjusted analysis (adjusted SHR, 0.89; 95% CI, 0.41-1.92; P = 0.77).

DISCUSSION

TDF and ETV did not significantly differ in the prevention of HCC in patients with CHB.

Risk factors associated with hypophosphatemia in chronic Hepatitis B patients treated with tenofovir disoproxil fumarate

Tenofovir disoproxil fumarate (TDF) is thought to cause varying degrees of hypophosphatemia in patients with chronic hepatitis B (CHB). Therefore, we investigated factors that cause hypophosphatemia in patients treated with TDF and methods to increase serum phosphorus concentrations in clinical practice.We completed a retrospective review of patients with CHB treated with TDF initially at Kosin University Gospel Hospital, Busan, Korea from January 2012 to January 2017. Subclinical hypophosphatemia and hypophosphatemia were defined as serum phosphorus below 3.0 mg/dL and 2.5 mg/dL, respectively.We screened 206 patients with CHB treated with TDF, among which 135 were excluded for the following reasons: baseline malignancy (59), limited data (50), co-administered other antivirals (14), hypophosphatemia at baseline (7), and other reasons (5). The final study population comprised 71 patients. Subclinical hypophosphatemia developed in 43 (60.5%) patients. Hypophosphatemia occurred in 18 patients (25.3%). Liver cirrhosis was the most significant predictor of hypophosphatemia (P = .038, OR = 3.440, CI = 1.082-10.937) Patients diagnosed with subclinical hypophosphatemia were encouraged to increase their intake of nuts and dairy products (25 patients) or reduce their alcohol intake (2), dose reduction of TDF (4) or placed under observation (4). Among patients with subclinical hypophosphatemia, serum phosphorus concentrations were elevated (>3.0 mg/dL) in 23 of 36 patients (63.8%). Increased nut and dairy intake increased phosphorus concentrations to more than 3.0 mg/dl in 16 of 25 patients (64.0%).Entecavir or tenofovir alafenamide fumarate (TAF) should be considered rather than TDF in patients with liver cirrhosis because of the risk of hypophosphatemia. Instead of stopping TDF treatment, encouraging increased intake of phosphorus-rich foods could increase serum phosphorus concentrations in clinical practice.

Entecavir treatment of hepatitis B virus-infected patients with severe renal impairment and those on hemodialysis

AIM

Entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) are first-line nucleos(t)ide analogues for hepatitis B virus (HBV)-infected patients. However, consecutive TDF treatment causes renal dysfunction, and the safety and efficacy of TAF have not been established in severe renal dysfunction patients, including hemodialysis patients. The efficacy and safety of ETV in these populations has not been clarified. The study aimed to clarify this.

METHODS

In this retrospective multicenter study, between 2006 and 2018, a total of 567 HBV-infected patients treated with ETV monotherapy were screened. Patients were included if >20 years old, treated with ETV monotherapy for >1 year, and had proper clinical information. The efficacy of ETV and changes in renal function were evaluated according to renal function.

RESULTS

A total of 273 patients were included: 9.2% (25/273), 1.8% (5/273), and 3.7% (10/273) had chronic kidney disease (CKD) stage G3, CKD stage G4/5, and were on hemodialysis, respectively. Overall, 84.2%, 94.0%, and 96.2% of patients experienced serum HBV-DNA disappearance at 1, 2, and 3 years, respectively, after treatment initiation. In patients with CKD stage G3-5, estimated glomerular filtration rate tended to restore with time, which was in contrast to patients without renal dysfunction. The rate of disappearance in serum HBV-DNA, alanine transaminase normalization, and virological breakthrough was similar between patients with or without renal dysfunction. ETV showed high efficacy for all 10 hemodialysis patients without virological breakthrough.

CONCLUSIONS

Entecavir for HBV-infected patients with severe renal dysfunction, including hemodialysis patients, is highly effective and does not affect renal function.

Efficacy and safety of tenofovir disoproxil fumarate in Chinese patients with chronic hepatitis B virus infection: A 2-year prospective study

To date, a small number of studies concerning the effects and safety of tenofovir disoproxil fumarate (TDF) in Chinese individuals were conducted. In this study, we aimed to assess the antiviral effects and nephrotoxicity of TDF in Chinese patients with chronic hepatitis B virus (HBV) infection.Patients with chronic HBV infection were prospectively recruited and TDF treatment was given for 96 weeks. HBV serologic markers, HBV DNA, creatinine and phosphorus were collected.Fifty-seven treatment-naïve and 48 treatment-experienced patients were recruited. Irrespective of the prior treatment history, more than 95% of patients achieved virological response during 96 weeks treatment with TDF. Estimated glomerular filtration rate (eGFR) significantly declined in the first year of treatment in patients with chronic hepatitis B or younger age (<65 years old) (both P < .05), while that was not achieved in patients with liver cirrhosis or older age (≥65 years old) (both P > .05). For patients who were treatment-naïve or treated previously with adefovir dipivoxil, eGFR declined at the 48th week; however, eGFR was partially recovered at the 96th week. Furthermore, multivariable analysis showed that basal eGFR <90 mL/min/1.73 m (P = .001; odds ratio: 4.821; 95% confidence interval: 1.904-12.206) is the only independent risk factor for eGFR <90 mL/min/1.73 m at the 96th week.TDF has potent antiviral effect in both treatment-naïve and treatment-experienced patients.

Comparison of renal safety of tenofovir and entecavir in patients with chronic hepatitis B: Systematic review with meta-analysis

BACKGROUND

Recently, the American Association for the Study of Liver Disease suggested no preference between tenofovir (TDF) and entecavir (ETV) regarding potential long-term risks of renal complications. Over the years, renal safety has become a critical concern in nucleos(t)ide analog-treated patients due to the long-term use of these drugs. However, existing studies do not show significant differences in renal dysfunction between these two drugs. Further, there is a paucity of studies comparing the long-term renal effects of TDF and ETV.

AIM

To investigate the effects of TDF and ETV on renal function, we performed systematic review and meta-analysis.

METHODS

Two investigators independently searched the Cochrane Library, MEDLINE, and Embase databases for randomized controlled trials and nonrandomized studies (NRSs) using the keywords “CHB”, “Tenofovir”, and “Entecavir”, and additional references were obtained from the bibliographies of relevant articles published through December 2017. The quality of each study was assessed using the Newcastle-Ottawa scale and the Grading of Recommendations Assessment, Development and Evaluation criteria. The primary outcome was the change in serum creatinine level in the TDF and ETV groups at baseline, 6 mo, 12 mo and 24 mo.

RESULTS

Nine NRSs comprising 2263 participants met the inclusion criteria. Changes in creatinine levels were higher in the TDF group than in the ETV group at 6 mo [mean difference (MD) = 0.03 mg/dL; 95%CI: 0.02-0.04; I² = 0%], 12 mo (MD = 0.05 mg/dL; 95%CI: 0.02-0.08; I² = 78%), and 24 mo (MD = 0.07 mg/dL; 95%CI: 0.01-0.13; I² = 93%). The change in estimated glomerular filtration rate (eGFR) was significantly higher in the TDF group than in the ETV group at 6 mo [standardized mean difference (SMD), -0.22; 95%Cl: -0.36--0.08; I² = 0%], 12 mo (SMD = -0.24; 95%Cl: -0.43--0.05; I² = 50%), and 24 mo (-0.35; 95%Cl: -0.61- -0.09; I² = 67%).

CONCLUSION

TDF statistically significantly increased serum creatinine levels and decreased the eGFR in 6-24 mo compared to ETV, with moderate to low quality of evidence. However, the differences are negligible.

CMCdG, a Novel Nucleoside Analog with Favorable Safety Features, Exerts Potent Activity against Wild-Type and Entecavir-Resistant Hepatitis B Virus

We designed, synthesized, and characterized a novel nucleoside analog, (1S,3S,5S)-3-(2-amino-6-oxo-1,6-dihydro-9H-purin-9-yl)-5-hydroxy-1-(hydroxymethyl)-2-methylene-cyclopentanecarbonitrile, or 4'-cyano-methylenecarbocyclic-2'-deoxyguanosine (CMCdG), and evaluated its anti-hepatitis B virus (anti-HBV) activity, safety, and related features. CMCdG's in vitro activity was determined using quantitative PCR and Southern blotting assays, and its cytotoxicity was determined with a 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assay, while its in vivo activity and safety were determined in human liver-chimeric mice infected with wild-type HBV genotype Ce (HBVWTCe) and an entecavir (ETV)-resistant HBV variant containing the amino acid substitutions L180M, S202G, and M204V (HBVETV-RL180M/S202G/M204V). CMCdG potently inhibited HBV production in HepG2.2.15 cells (50% inhibitory concentration [IC50], ∼30 nM) and HBVWTCe plasmid-transfected Huh7 cells (IC50, 206 nM) and efficiently suppressed ETV-resistant HBVETV-RL180M/S202G/M204V (IC50, 2,657 nM), while it showed no or little cytotoxicity (50% cytotoxic concentration, >500 μM in most hepatocytic cells examined). Two-week peroral administration of CMCdG (1 mg/kg of body weight/day once a day [q.d.]) to HBVWTCe-infected human liver-chimeric mice reduced the level of viremia by ∼2 logs. CMCdG also reduced the level of HBVETV-RL180M/S202G/M204V viremia by ∼1 log in HBVETV-RL180M/S202G/M204V-infected human liver-chimeric mice, while ETV (1 mg/kg/day q.d.) completely failed to reduce the viremia. None of the CMCdG-treated mice had significant drug-related changes in body weights or serum human albumin levels. Structural analyses using homology modeling, semiempirical quantum methods, and molecular dynamics revealed that although ETV triphosphate (TP) forms good van der Waals contacts with L180 and M204 of HBVWTCe reverse transcriptase (RT), its contacts with the M180 substitution are totally lost in the HBVETV-RL180M/S202G/M204V RT complex. However, CMCdG-TP retains good contacts with both the HBVWTCe RT and HBVETV-RL180M/S202G/M204V RT complexes. The present data warrant further studies toward the development of CMCdG as a potential therapeutic for patients infected with drug-resistant HBV and shed light on the further development of more potent and safer anti-HBV agents.