Tenofovir alafenamide for hepatitis B virus infection including switching therapy from tenofovir disoproxil fumarate

Observational pilot study of switching from entecavir to tenofovir alafenamide in patients with chronic hepatitis B

This study evaluated the long-term efficacy and safety of the widely used drugs entecavir (ETV) and tenofovir alafenamide (TAF), as well as the incidence of HCC.A nonrandomized, prospective, observational analysis included 77 patients with chronic hepatitis B who were assigned to continue ETV or switch TAF. After 240 weeks, the mean changes in serum hepatitis B surface antigen (- 0.365 ± 0.069 log IU/mL vs. 0.301 ± 0.039 log IU/mL, p = 0.39) and hepatitis B core-related antigen (- 0.215 ± 0.092 log IU/mL vs. - 0.195 ± 0.056 log IU/mL) were not significantly different between the ETV and TAF groups. There were also no differences between the two groups in estimated glomerular filtration rate (- 5.407 ± 1.660 vs. - 2.666 ± 1.52, p = 0.240), urinary β2-microglobulin β/creatinine (ETV: 2.330 ± 0.374 at baseline and 2.335 ± 0.257 at 240 weeks; TAF: 2.720 ± 0.073 and 2.123 ± 0.310, p = 0.996 and 0.455, respectively) or urinary N-acetyl-β-D-glucosaminidase/creatinine (ETV: 0.040 ± 0.005 at baseline and 0.044 ± 0.004 at 240 weeks; TAF: 0.049 ± 0.005 and 0.053 ± 0.005, p = 0.642 and 0.684, respectively). Finally, no significant difference was found in the incidence of HCC between the ETV and TAF groups (log-rank test, p = 0.08). In conclusion, the long-term observation of this study demonstrated that ETV and TAF have comparable efficacy and safety.Clinical trial registration: UMIN000026465.

Dynamic evaluation of liver fibrosis to assess hepatocellular carcinoma risk in patients with chronic hepatitis B receiving nucleoside analogs treatment

Despite good hepatitis B virus (HBV) inhibition by nucleoside analogs (NAs), cases of hepatocellular carcinoma (HCC) still occur. This study proposed a non-invasive predictive model to assess HCC risk in patients with chronic hepatitis B (CHB) receiving NAs treatment. Data were obtained from a hospital-based retrospective cohort registered on the Platform of Medical Data Science Academy of Chongqing Medical University, from 2013 to 2019. A total of 501 patients under NAs treatment had their FIB-4 index updated semiannually by recalculation based on laboratory values. Patients were divided into three groups based on FIB-4 index values: < 1.45, 1.45-3.25, and ≥ 3.25. Subsequently, HCC incidence was reassessed every six months using Kaplan-Meier curves based on the updated FIB-4 index. The median follow-up time of CHB patients after receiving NAs treatment was 2.5 years. HCC incidences with FIB-4 index < 1.45, 1.45-3.25, and ≥ 3.25 were 1.18%, 1.32%, and 9.09%, respectively. Dynamic assessment showed that the percentage of patients with FIB-4 index < 1.45 significantly increased semiannually (P < 0.001), and of patients with FIB-4 index ≥ 3.25 significantly decreased (P < 0.001). HCC incidence was the highest among patients with FIB-4 index ≥ 3.25. The FIB-4 index effectively predicted HCC incidence, and its dynamic assessment could be used for regular surveillance to implement early intervention and reduce HCC risk.

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

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

Increased spine bone density in patients with chronic hepatitis B switched to tenofovir alafenamide: A prospective, multinational study

BACKGROUND

Data on patients switched to tenofovir alafenamide (TAF) from nucleos(t)ide analogues (NUCs) other than tenofovir disoproxil fumarate are limited.

AIMS

To assess the treatment and renal/bone safety outcomes following the switch to TAF.

METHODS

We prospectively enrolled adult patients with chronic hepatitis B (CHB) who switched from any NUC to TAF at 14 centres in Japan, Korea, Taiwan and the U.S. Study outcomes were viral suppression (VR; HBV DNA < 20 IU/mL), biochemical response (BR; alanine aminotransferase normalisation), and changes in estimated glomerular filtration rate (eGFR) and T-scores (L-spine) by bone absorptiometry by 24 months after switch to TAF.

RESULTS

We enrolled 270 eligible patients. Mean age was 58.1; 58.2% were male; 12.2% had cirrhosis and 73.3% previously received entecavir monotherapy. VR rate increased significantly from 95.2% to 98.8% by 24 months after the switch to TAF (p = 0.014). Between the switch and 24 months later, the mean spine T-score improved significantly from -1.43 ± 1.36 to -1.17 ± 1.38 (p < 0.0001), while there was no significant change in mean eGFR (88.4 ± 16.9-89.5 ± 16.3 mL/min/1.73 m2 , p = 0.13). On multivariable analysis adjusted for age, sex, baseline spine T-score and prior TDF or adefovir dipivoxil use, male sex was significantly associated with lower risk of worsening spine T-score (odds ratio: 0.29, p = 0.020), while age was significantly associated with a higher risk of worsening chronic kidney disease stage (OR: 1.07, p = 0.019).

CONCLUSIONS

At 24 months after the switch to TAF, VR rates and spine bone density improved significantly while renal function remained stable.

Tenofovir alafenamide and tenofovir disoproxil fumarate reduce incidence of hepatocellular carcinoma in patients with chronic hepatitis B

BACKGROUND & AIMS

Antiviral therapy may attenuate the risk of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB). We aimed to explore how tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) affect HCC risk in patients with CHB.

METHODS

The REACH-B, aMAP, and mPAGE-B models were utilized to assess HCC risk in patients with CHB from two global randomized-controlled trials evaluating the impact of TAF vs. TDF treatment. Standard incidence ratios (SIRs) were calculated using data from the REACH-B model as a ratio of observed HCC cases in the TAF- or TDF-treated patients vs. predicted HCC cases for untreated historical controls. Proportions of treated patients shifting aMAP and mPAGE-B risk categories between baseline and Week 240 were calculated.

RESULTS

Of the 1,632 patients (TAF, n = 1,093; TDF, n = 539) followed for up to 300 weeks, 22 HCC cases developed. Those receiving TAF had an SIR that was lower compared to the SIR of individuals receiving TDF: 0.32 (p <0.001) vs. 0.56 (p = 0.06). In the general study population, individuals without cirrhosis at baseline had an SIR that was lower compared to the SIR of individuals with cirrhosis at baseline: 0.37 (p <0.001) vs. 0.58 (p = 0.15). Of the patients at low risk of HCC at baseline, the majority (97%) remained low risk by mPAGE-B and aMAP scoring at Week 240. Among those at medium or high risk at baseline, substantial portions shifted to a lower risk category by Week 240 (mPAGE-B: 22% and 42%; aMAP: 39% and 63%, respectively).

CONCLUSIONS

This evaluation provides evidence that treatment with TAF or TDF can reduce HCC risk in patients with CHB, particularly in patients without cirrhosis.

IMPACT AND IMPLICATIONS

Despite the substantial impact of HCC on long-term outcomes of patients with CHB, the differential risk of HCC development among those receiving treatment with TAF vs. TDF has not been well elucidated. Using three validated risk prediction models, we found that TAF is at least as effective as TDF in reducing HCC risk in patients with CHB. While TDF is well-studied in the context of HCC risk reduction, our novel findings underscore the effectiveness of TAF as a treatment option for patients with CHB.

CLINICAL TRIAL NUMBERS

NCT01940341; NCT02836249; NCT01940471; NCT02836236.

Retreatment Efficacy and Renal Safety of Tenofovir Alafenamide, Entecavir, and Tenofovir Disoproxil Fumarate After Entecavir or Tenofovir Cessation

BACKGROUND

We aimed to compare the one-year retreatment efficacy and renal safety of entecavir, tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) after HBV relapse in patients who discontinued entecavir or TDF.

METHODS

This retrospective study included 289 chronic hepatitis B (CHB) patients without cirrhosis who received entecavir (n = 93), TDF (n = 103), or TAF (n = 86) retreatment for at least 12 months after entecavir or TDF cessation.

RESULTS

The rate of virological response (HBV DNA < 20 IU/mL) at 12 months of retreatment was 79/93 (84.9%) in the entecavir group, 92/103 (89.3%) in the TDF group, and 72/86 (83.7%) in the TAF group. The rate of ALT normalization (ALT ≤ 40 U/L) after 12 months of retreatment was 76/93 (81.7%) in the entecavir group, 77/103 (74.7%) in the TDF group , and 73/86 (84.9%) in the TAF group. There was no significant difference in the rates of virological response (p = 0.495) and ALT normalization (p = 0.198) among the three groups. Multivariate analysis showed that lower HBV DNA and HBsAg levels at baseline were independently associated with virological response at 12 months of retreatment. The TDF group (37.8 ± 34.8 U/L) had higher ALT levels at 12 months of retreatment than the TAF (27. ± 17.9 U/L, p = 0.015) and entecavir (28.3 ± 19.3 U/L, p = 0.022) groups. In patients with eGFR 60-90 mL/min/1.73 m², eGFR change between baseline and 12 months of retreatment increased in the entecavir and TAF groups and decreased in the TDF group.

CONCLUSIONS

TAF could be one of the retreatment options for retreatment of HBV relapse after entecavir or TDF cessation.

Renal Outcomes With Tenofovir Alafenamide in Liver Transplant Recipients

Tenofovir disoproxil fumarate (TDF) is associated with a higher risk of nephrotoxicity compared with entecavir (ETV) or tenofovir alafenamide (TAF).1,2 One-fifth of transplant recipients develop chronic kidney disease (CKD) within 5 years after transplantation, contributed by the use of nephrotoxic immunosuppressive medications.3 Prior studies conducted in the nontransplant setting reported superior renal safety in TAF compared with TDF but data in liver transplant (LT) recipients have so far been limited to small case series.1,4-6 Therefore, the goals of this study were to examine changes in renal function in a large multicenter cohort of LT recipients with chronic hepatitis B who were treated with TAF, TDF, or ETV for the prevention of hepatitis B virus (HBV) reinfection or reactivation from receipt of a positive HBV core antibody graft.

Perspectives on the Underlying Etiology of HCC and Its Effects on Treatment Outcomes

Hepatocellular carcinoma (HCC) continues to be a serious medical problem with poor prognosis worldwide. The distribution of the major etiologies of HCC is changing due to the progress of anti-viral treatments, including hepatitis B virus (HBV) suppression by nucleoside/nucleotide analogues (NAs) and increased sustained virologic response (SVR) rates by direct-acting antivirals (DAAs) for hepatitis C virus (HCV), as well as the rising trend of nonviral liver disease. Although viral hepatitis remains the most common cause of HCC, non-alcoholic liver disease (NAFLD) with metabolic syndrome and alcohol-associated liver disease (ALD) are increasing. Effective and well-tolerated NAs treatment can slow the disease progression of chronic HBV infection to cirrhosis, end-stage liver disease, and reduce HCC risk. Treatment with NAs is also associated with significant improvement in the long-term survival of patients with HBV infection who already have HCC. DAAs have achieved viral elimination in almost all patients with HCV without significant adverse events, even in patients with decompensated liver cirrhosis and HCC. Similarly, DAA therapy can reduce disease progression, liver and non-liver complications, and improve the long-term survival of patients with chronic HCV infection with or without HCC. Meanwhile, NAFLD is a rapidly increasing cause of HCC along with the epidemics of obesity and type 2 diabetes globally. NAFLD-related HCC can occur in patients without cirrhosis and is known to have a lower survival rate than viral hepatitis-related HCC. Since there is currently no specific pharmacotherapy effective for NAFLD, lifestyle modification and prevention of complications are important to improve prognosis. Additionally, ALD is the second fastest-growing cause of HCC-related deaths, especially with an accelerated trend since the COVID-19 pandemic. This review provides an overview of the epidemiologic trends in the etiologies of HCC, and the progress of treatments for each etiology and the impact on outcome in the patients with HCC.

Alanine aminotransferase levels as therapeutic targets after nucleotide/nucleoside analog therapy in patient with chronic hepatitis B

AIM

Alanine aminotransferase (ALT) is a criterion for the introduction of nucleotide/nucleoside analog (NA), and ALT levels are decreased by NA treatment. However, the association between post-treatment ALT levels and hepatocellular carcinoma (HCC) risk remains unclear. To fill this gap, we aimed to establish a target value of ALT level during NA treatment.

METHODS

In total, 413 patients with chronic hepatitis B who received entecavir, tenofovir alafenamide, or tenofovir disoproxil fumarate were enrolled. The subsequent development of HCC was examined and a target value of ALT level during NA treatment as a risk marker for HCC was evaluated.

RESULTS

The median follow-up duration was 5.1 years, during which time 27 patients (8.6%) developed HCC. ALT level at the start of treatment was not associated with HCC development (p = 0.08). When stratified by ALT at 1 year after NA initiation, the cumulative 3- and 5-year rates of HCC for patients with ALT ≥21 IU/L were 11.5% and 18.1%, and those with ALT <21 IU/L was 2.3% and 6.5%, respectively. Patients with ALT <21 IU/L had a significantly lower risk of HCC development compared with patients with ALT ≥21 IU/L (p = 0.002). In multivariable analysis adjusting age, sex, and platelet counts, ALT ≥21 IU/L was an independent risk factor of HCC development with hazard ratio of 4.5 (95% confidence interval: 1.01-20.4).

CONCLUSIONS

ALT <21 IU/L at 1 year after NA initiation has a lower risk of HCC and could be used as a target value for NA treatment.

Comparative Performance of 14 HCC Prediction Models in CHB: A Dynamic Validation at Serial On-Treatment Timepoints

INTRODUCTION

To assess comparative performance of 14 hepatocellular carcinoma (HCC) prediction models in chronic hepatitis B (CHB) patients using on-treatment values at different timepoints.

METHODS

Based on a nationwide prospective cohort of 986 treatment-naive CHB patients undergoing entecavir therapy with every 26-week follow-up, 14 HCC risk scores were calculated using on-treatment values at week 26, 52, 78, and 104, respectively. Model performance predicting 3-year HCC was assessed using time-dependent area under the receiver operating characteristic curve (AUC) and calibration index. Model cutoffs were validated through common diagnostic accuracy measures.

RESULTS

During median 4.7-year follow-up, 56 (7.5%) developed HCC. Discrimination using on-treatment values within first 2 years was generally acceptable for most models (AUCs ranging from 0.68 to 0.81), except for REACH-B, NGM-HCC, and PAGE-B, although AUCs slightly decreased from week 26 to 104. Of these, REAL-B, CAMD, GAG-HCC, AASL-HCC, LSM-HCC, mPAGE-B, and mREACH-BII showed highest discrimination with AUCs ranging from 0.76 to 0.81, 0.72 to 0.76, 0.70 to 0.76, and 0.71 to 0.74 when reassessment at week 26, 52, 78, and 104, respectively. With reassessment within first 2 years, both REAL-B and CAMD calibrated well (Brier score ranging from 0.037 to 0.052). Of 9 models reporting cutoffs, REAL-B, AASL-HCC, and mPAGE-B using on-treatment values could identify 30%-40% of patients as low risk with minimal HCC incidence in the low-risk group (0.40% [REAL-B]-1.56% [mPAGE-B]).

DISCUSSION

In this undergoing antiviral treatment CHB cohort, most HCC prediction models performed well even using on-treatment values during first 2 years, particularly REAL-B, AASL-HCC, CAMD, and mPAGE-B model.

First-line therapies for hepatitis B in the United States: A 3-year prospective and multicenter real-world study after approval of tenofovir alefenamide

Real-world data are limited on tenofovir alafenamide (TAF). We aimed to study TAF real-world outcomes with other first-line regimens for chronic hepatitis B (CHB). We enrolled patients with CHB from 10 centers retrospectively and followed them for 36 months prospectively. We analyzed switching patterns of antiviral therapy and treatment outcomes of TAF, tenofovir disoproxil fumarate (TDF), and entecavir therapy. For efficacy and safety, we analyzed a subset of patients with complete data at 24 months after switching to TAF or remaining on TDF or entecavir. Among 1037 enrollees, 889 patients were analyzed. The mean age was 52%, and 72% were hepatitis B e antigen-negative. After enrollment, shifts in therapies were mostly in reduced use of TDF from 63% to 30% due to switching to TAF. Clinical parameters were compared at enrollment or initiation to measures at 24 months for patients remaining on TAF (187), TDF (229), or entecavir (181). At 24 months, a significantly higher portion of patients on TAF achieved hepatitis B virus (HBV) DNA ≤ 20 IU/ml (93% vs. 86%; p = 0.012) and normalized alanine aminotransferase (ALT) (66% vs. 56%; p = 0.031) with stable estimated glomerular filtration rates (eGFRs). However, a higher percentage of the patient with eGFR < 60 ml/mi/1.7 m2 was observed in the TDF-treated group (9% vs. 4%; p = 0.010). In patients who remained on entecavir or TDF for 24 months, ALT and HBV-DNA results did not differ significantly from baseline. Treatment of CHB in the United States has significantly shifted from TDF to TAF. Our data suggest that switching from TDF or entecavir to TAF may result in increased frequency of ALT normalization and potential clearance of viremia at the 24-month time point.

Body weight changes in treated hepatitis B patients switching to tenofovir alafenamide☆

BACKGROUND/PURPOSE

Switching to a tenofovir alafenamide (TAF)-containing regimen has been reported to be associated with body weight gain in human immunodeficiency virus-infected subjects. We aimed to investigate the body weight change and virological, hepatic, and renal outcomes of TAF switching among chronic hepatitis B (CHB) patients.

METHODS

This retrospective study included 121 CHB patients who were switched to TAF after >12 months of treatment with another nucleot(s)ide analog (NUC). All patients were monitored for 12 months.

RESULTS

The cohort was mostly Asian (96.7%) with a mean age of 55 years, 72% male, 14% cirrhosis, 21% HBeAg positive, and 75% with prior use of tenofovir disoproxil fumarate. At 12 months after TAF switching, their body weight significantly increased from 66.4 ± 11.8 to 67.8 ± 12.3 kg (p < 0.001), and 21.1% of the subjects had a ≥5% weight gain. Patients without diabetes or hypertension were more likely to have a body weight gain. Meanwhile, the complete viral suppression rate increased significantly from 89.3% to 96.2% (p = 0.016). The rate of alanine aminotransferase normalization also increased significantly from 71.1% to 87.6% (p < 0.001) by local criteria and from 58.7% to 70.2% (p = 0.029) by AASLD criteria. The mean eGFR (mL/min/1.73 m2) did not change (88.2 ± 18.8 vs. 87.2 ± 17.5, p = 0.28). However, for the subgroup with GFR <90 at TAF switching, there was a significant improvement in eGFR (72.9 ± 12.0 vs. 75.7 ± 14.2, p = 0.027).

CONCLUSION

In real-world NUC-experienced CHB patients, unexpected body weight gain was observed after TAF switching. The mechanism needs to be investigated in the future.

One-year efficacy of tenofovir alafenamide in patients with chronic hepatitis B: An observational study

Non-inferior antiviral efficacy and better renal safety have been reported in chronic hepatitis B patients with tenofovir alafenamide (TAF) treatment. The experience in real-world clinical practice is limited.We aimed to explore the efficacy after 1-year TAF treatment.A total of 148 patients (42 HBeAg-positive and 106 HBeAg-negative) with TAF treatment ≥1 year were included. Virological suppression (<20 IU/mL or undetectable), HBsAg level, alanine aminotransferase (ALT) normalization (≤36 U/L), and estimated glomerular filtration rate (eGFR) were analyzed at 1 year. Multivariate logistic regression analysis was performed to determine the associated factors for virological suppression and ALT normalization.Virological suppression was achieved in 83% and the 1-year median decline of hepatitis B virus DNA was 5.18 log IU/mL. ALT normalization occurred in 75.7%. HBsAg level decreased at a median of 0.27 log IU/mL with significant difference from baseline (P < .001). Baseline ALT (odds ratio [OR] 1.005, 95% confidence interval [CI] 1.000-1.010, P = .036) and hepatitis B virus DNA (OR 0.222, 95% CI 0.079-0.621, P = .004) were significant factors for 1-year virological suppression. Age (OR 1.064, 95% CI 1.003-1.130, P = .041) was associated with ALT normalization. Significant changes were observed in creatinine (mean increase 0.03 mg/dL, P = .011) and eGFR (mean decrease 2.6 mL/min/1.73 m2, P = .004) after 1-year TAF treatment.One-year TAF treatment came to good virological response, modest ALT normalization rate and significant HBsAg decline. The observation of significant changes in eGFR warranted further studies.

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

BACKGROUND

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Comparison of biochemical response during antiviral treatment in patients with chronic hepatitis B infection

BACKGROUND & AIMS

This multicenter cohort study aimed to compare the real-world biochemical response rates during tenofovir alafenamide (TAF), tenofovir disoproxil fumarate (TDF), and entecavir (ETV) treatment in chronic hepatitis B virus (HBV) infection patients.

METHODS

Overall, 1282 treatment-naïve patients with CHB who commenced TAF (n = 270), TDF (n = 617), or ETV (n = 395) were analysed for biochemical response rates during the antiviral treatment using a time-dependent Cox proportional hazard model after the inverse probability of treatment weighting (IPTW).

RESULTS

Patients treated with ETV were older (55.1 ± 11.5 years) than TAF or TDF (P < .0001). ETV was more frequently prescribed to patients with diabetes mellitus (DM, P = .003), hypertension (P < .0001), chronic kidney disease (P < .0001), and negative e-antigen (P < .0001). Cumulative biochemical response rate was independently lower in patients with radiologic fatty liver (HR, 0.75; 95% CI, 0.61-0.94) and obese patients without DM (HR, 0.85; 95% CI, 0.68-0.98) according to multivariable Cox analyses based on time-dependent variables after IPTW for age, sex, liver cirrhosis, baseline e-antigen, ALT, and HBV DNA levels. ETV treated patients (HR, 1.38; 95% CI, 1.13-1.68) showed higher biochemical response rates compared with TAF- or TDF-treated patients after adjusting for similar parameters.

CONCLUSIONS

In real-world practice, ETV was preferable for older, hepatitis B e-antigen negative patients with underlying comorbidities. Biochemical responses in patients treated with ETV, TAF, and TDF were significantly affected by metabolic factors such as fatty liver, obesity, and DM. However, the mechanism behind the higher biochemical response rate in patients treated with ETV should be investigated further.

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.

Hepatocellular Carcinoma Prediction Models in Chronic Hepatitis B: A Systematic Review of 14 Models and External Validation

BACKGROUND & AIMS

The aim of our study was to characterize the performance of hepatocellular carcinoma (HCC) prediction models in chronic hepatitis B (CHB) patients through meta-analysis followed by external validation.

METHODS

We performed a systematic review and meta-analysis of current literature, followed by external validation in independent multi-center cohort with 986 patients with CHB undergoing entecavir treatment (median follow-up: 4.7 years). Model performance to predict HCC within 3, 5, 7, and 10 years was assessed using area under receiver operating characteristic curve (AUROC) and calibration index. Subgroup analysis were conducted by treatment status, cirrhotic, race and baseline alanine aminotransferase.

RESULTS

We identified 14 models with 123,885 patients (5,452 HCC cases), with REACH-B, CU-HCC, GAG-HCC, PAGE-B and mPAGE-B models being broadly externally validated. Discrimination was generally acceptable for all models, with pooled AUC ranging from 0.70 (95% CI, 0.63-0.76 for REACH-B) to 0.83 (95% CI, 0.78-0.87 for REAL-B) for 3-year, 0.68 (95% CI, 0.64-0.73 for REACH-B) to 0.81 (95% CI, 0.77-0.85 for REAL-B) for 5-year and 0.70 (95% CI, 0.58-0.80 for PAGE-B) to 0.81 (95% CI, 0.78-0.84 for REAL-B and 0.77-0.86 for AASL-HCC) for 10-year prediction. However, calibration performance was poorly reported in most studies. In external validation cohort, REAL-B showed highest discrimination with 0.76 (95% CI, 0.69-0.83) and 0.75 (95% CI, 0.70-0.81) for 3 and 5-year prediction. The REAL-B model was also well calibrated in the external validation cohort (3-year Brier score 0.066). Results were consistent in subgroup analyses.

CONCLUSIONS

In a systematic review of available HCC models, the REAL-B model exhibited best discrimination and calibration.

Hepatitis B Core-Related Antigen and New Therapies for Hepatitis B

The hepatitis B core-related antigen (HBcrAg) is an unprecedented novel HBV biomarker that plays an essential role in reflecting covalently closed circular DNA (cccDNA) in chronic hepatitis B (CHB) because its levels correlate with intrahepatic cccDNA and serum HBV DNA. In this review, we describe the clinical application of serum HBcrAg in CHB patients, with a particular focus on new therapies targeting intrahepatic HBV replication. (1) HBcrAg can be detected in clinical cases where serum HBV DNA is undetectable during anti-HBV therapy. (2) A highly sensitive HBcrAg assay (iTACT-HBcrAg) may be useful for monitoring HBV reactivation, as an alternative to HBV DNA. (3) Decreased HBcrAg levels have been significantly associated with promising outcomes in CHB patients, reducing the risk of progression or recurrence of hepatocellular carcinoma. Additionally, we focus on and discuss several drugs in development that target HBV replication, and monitoring HBcrAg may be useful for determining the therapeutic efficacies of such novel drugs. In conclusion, HBcrAg, especially when measured by the recently developed iTACT-HBcrAg assay, may be the most appropriate surrogate marker, over other HBV biomarkers, to predict disease progression and treatment response in CHB patients.

Tenofovir alafenamide for prevention and treatment of hepatitis B virus reactivation and de novo hepatitis

Background and Aim

Administration of tenofovir alafenamide (TAF) as prevention or treatment of hepatitis B virus (HBV) reactivation is not well known. The aim of this study is to reveal the efficacy and safety of TAF against HBV reactivation.

Methods

Entecavir (ETV) and TAF were given to 66 and 11 patients, respectively, as prophylaxis against or treatment of HBV reactivation during chemotherapy or immune suppression therapy from January 2010 to June 2020. The antiviral effects and safety were assessed.

Results

At week 24, the antiviral effects on patients receiving ETV and TAF were similar in terms of reduction of HBV DNA (-2.83 ± 1.45log IU/mL vs -3.05 ± 2.47log IU/mL; P = 0.857) and achieving undetectable levels of HBV DNA (78.8 vs 90.9%; P = 0.681). There was no significant difference in the decrease in the estimated glomerular filtration rate (eGFR) between the two groups (-0.62 ± 11.2 mL/min/1.73 m² vs -3.67 ± 13.2 mL/min/1.73 m²; P = 0.291).

Conclusion

TAF is safe and effective against HBV reactivation.

[Prevention of gastrointestinal cancer]

Throughout the past decades, considerable progress has been made in the (early) diagnosis and treatment of gastrointestinal cancers. However, the prognosis for advanced stages of gastrointestinal tumors remains limited for many patients and approximately one third of all tumor patients die as a result of gastrointestinal tumors. The prevention and early detection of gastrointestinal tumors is therefore of great importance.For this reason, we summarize the current state of knowledge and recommendations for the primary, secondary and tertiary prevention of esophageal, stomach, pancreas, liver and colorectal cancer in the following.

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.

Development, Characterization and In Vivo Pharmacokinetic Assessment of Rectal Suppositories Containing Combination Antiretroviral Drugs for HIV Prevention

Receptive anal intercourse (RAI) contributes significantly to HIV acquisition underscoring the need to develop HIV prevention options for populations engaging in RAI practices. We explored the feasibility of formulating rectal suppositories with potent antiviral drugs for on-demand use. A fixed-dose combination of tenofovir (TFV) and elvitegravir (EVG) (40 mg each) was co-formulated in six different suppository bases (three fat- and three water-soluble). Fat-soluble witepsol H15 and water-soluble polyethylene glycol (PEG) based suppositories demonstrated favorable in vitro release and were advanced to assess in vivo pharmacokinetics following rectal administration in macaques. In vivo drug release profiles were similar for both suppository bases. Median concentrations of TFV and EVG detected in rectal fluids at 2 h were 1- and 2-logs higher than the in vitro IC50, respectively; TFV-diphosphate levels in rectal tissues met or exceeded those associated with high efficacy against rectal simian HIV (SHIV) exposure in macaques. Leveraging on these findings, a PEG-based suppository with a lower dose combination of tenofovir alafenamide (TAF) and EVG (8 mg each) was developed and found to achieve similar rectal drug exposures in macaques. This study establishes the utility of rectal suppositories as a promising on-demand strategy for HIV PrEP and supports their clinical development.

Progress and challenges in the comprehensive management of chronic viral hepatitis: Key ways to achieve the elimination

Chronic viral hepatitis is a significant health problem throughout the world, which already represents high annual mortality. By 2040, chronic viral hepatitis due to virus B and virus C and their complications cirrhosis and hepatocellular carcinoma will be more deadly than malaria, vitellogenesis-inhibiting hormone, and tuberculosis altogether. In this review, we analyze the global impact of chronic viral hepatitis with a focus on the most vulnerable groups, the goals set by the World Health Organization for the year 2030, and the key points to achieve them, such as timely access to antiviral treatment of direct-acting antiviral, which represents the key to achieving hepatitis C virus elimination. Likewise, we review the strategies to prevent transmission and achieve control of hepatitis B virus. Finally, we address the impact that the coronavirus disease 2019 pandemic has had on implementing elimination strategies and the advantages of implementing telemedicine programs.

Comparison of efficacy and safety of entecavir and switching from entecavir to tenofovir alafenamide fumarate in chronic hepatitis B: Long-term effects from a prospective study

AIM

Both entecavir (ETV) and tenofovir alafenamide fumarate (TAF) are widely used to treat chronic hepatitis B (CHB) in Japan. However, it remains unclear whether the efficacy of TAF in decreasing the hepatitis B surface antigen (HBsAg) level, and its safety, are superior to those of ETV. This study aimed to report the long-term effects and safety of 96-week ETV and TAF treatment in patients with CHB.

METHODS

A prospective comparative observational study was undertaken on the following two groups: patients with CHB who received continuous ETV (n = 32) and patients with CHB who were switched from ETV to TAF upon request (n = 48). The HBsAg, urinary β2-microglobulin (β2MG)/creatinine (Cr), urinary N-acetyl-β-D-glucosaminidase (NAG)/Cr, and serum alanine aminotransferase (ALT) levels, estimated glomerular filtration rate (eGFR), and bone mineral density (lumbar spine and femur) at 96 weeks were compared.

RESULTS

The two groups did not significantly differ with respect to mean age, male / female patient ratio, or rate of hepatitis B e antigen-positive status. The mean changes in serum HBsAg level and eGFR at 96 weeks were not significantly different between the two groups. The β2MG/Cr and NAG/Cr levels at 96 weeks were similar between the two groups. Additionally, the bone mineral density of the lumbar spine and femur as well as the serum ALT did not significantly differ.

CONCLUSIONS

When compared with patients who received continuous ETV, those who were introduced to TAF after ETV showed similar effects in terms of the decrease in HBsAg level and safety.

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.

Nucleos(t)ide analogue therapy: The role of tenofovir alafenamide

Chronic hepatitis B virus (HBV) infection remains an important global health problem, and may be difficult to manage in clinical practice. Nucleos(t)ide analogues (NAs) with a high barrier to resistance (entecavir [ETV], tenofovir disoproxil fumarate [TDF] and tenofovir alafenamide [TAF]) are the most frequently used HBV treatments because of their long-term effectiveness and tolerability. ETV may be less effective in patients with lamivudine-resistant strains, and TDF is associated with impaired renal function and reductions in bone mineral density. TAF, a new tenofovir prodrug, has been developed to overcome the less favourable safety profile of TDF. TAF is more stable in plasma, and higher tenofovir levels are achieved within cells at lower doses than with TDF. Several registration and real-life studies, performed up to week 144 of treatment, have shown that TAF is at least as effective as TDF, with higher rates of ALT normalization and significantly fewer kidney disturbances and changes in bone mineral density. No emergence of drug resistance has been found with TAF use. The main limitation to prescribing TAF is its price. The European Association for the Study of the Liver has suggested selecting TAF or ETV instead of TDF in patients >65 years old and in those with a risk of osteoporosis or renal abnormalities, and to prescribe TAF rather than ETV in patients previously exposed to NAs.

Effectiveness and Renal Safety of Tenofovir Alafenamide Fumarate among Chronic Hepatitis B Patients: Real-World Study

Tenofovir alafenamide fumarate (TAF) has high plasma stability resulting in fewer renal adverse events compared to tenofovir disoproxil fumarate (TDF) in chronic hepatitis B (CHB) patients. We aimed to study the effectiveness and renal safety of TAF in a real-world setting, in patients with or without compromised kidney function. CHB patients (Nucleos(t)ide Analogue [NA]-naïve or experienced) who received TAF >1 year from 11 academic institutions as part of the Canadian Hepatitis B Network (CanHepB) were included. Kidney function was measured by estimated glomerular filtration rate (eGFR) as per Cockcroft-Gault. Patients were followed for up to 160 weeks. Of 176 patients receiving TAF, 143 switched from NA (88% TDF), and 33(19%) were NA naïve. Majority of NA-naïve patients (75%) achieved undetectable HBV DNA after one year of TAF treatment. Majority of patients with eGFR <60 mL/min who had renal deterioration during TDF (76%) reversed to eGFR increase after one year of TAF (p=0.009). Among patients with stage 2 chronic kidney disease (CKD) (eGFR 60-89), the estimated eGFR decline during TDF was halted after switching to TAF (p=0.09). NA-experienced patients with abnormal ALT before TAF showed a significant decline after switching to TAF: -0.005 [-0.006 - -0.004] log₁₀ ULN U/L/month, p<0.001). In CHB patients, TAF was safe, well-tolerated and effective in this real-world cohort. Switching to TAF led to improved kidney function, particularly in those with stage 2 CKD, which suggests that the indication for TAF in the guidelines could be extended to patients with an eGFR higher than 60 mL/min.

Dynamic evaluation of hepatocellular carcinoma prediction models in patients with chronic hepatitis B receiving nucleotide/nucleoside analogue treatment

Carcinogenesis risk scores for chronic hepatitis B have been proposed, but it remains unclear whether these scores during nucleoside/nucleotide analogue (NA) therapy are useful for risk assessment. In this study, we examined changes of these scores and the predictability during NA treatment. 432 patients with no history of hepatocellular carcinoma (HCC) treated with NA were enrolled. PAGE-B, modified PAGE-B (mPAGE-B), and REACH-B scores were calculated at NA administration, 1 and 2 years after administration. The median follow-up duration was 5.1 years, during which 37 patients (8.6%) developed HCC. Cumulative incidence HCC development in patients with high risk of PAGE at NA administration, and 1 and 2 years after NA administration was significantly higher than those with intermediate and low-risk groups (p < .05 for all time points), whereas HCC incidence in patients with high risk of mPAGE-B and REACH-B at 2 years after NA administration were equivalent to those with intermediate and low-risk groups (p = .2 for mPAGE-B, and p = .1 for REACH-B). The area under the receiver operating characteristic (AUROC) for HCC development of PAGE-B at NA administration, and 1 and 2 years after administration were 0.773, 0.803 and 0.737, respectively. The AUROCs of PAGE-B at each point were continuously higher than those of REACH-B (0.646, 0.725, and 0.653, respectively) and mPAGE-B (0.754, 0.734, and 0.678, respectively).PAGE-B score has a high diagnostic accuracy for HCC development at any time point during NA treatment, indicating its potential use as a real-time monitor of HCC development.

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.

Comparison of the impact of tenofovir alafenamide and entecavir on declines of hepatitis B surface antigen levels

OBJECTIVE

Tenofovir alafenamide is a new prodrug of tenofovir that allows for the treatment of patients with hepatitis B virus (HBV) at a lower dose than with tenofovir disoproxil fumarate, due to the more efficient delivery of tenofovir to hepatocytes. In this study, we compared entecavir and tenofovir alafenamide in terms of their ability to reduce hepatitis B surface antigen (HBsAg) in the same group of patients with HBV infection.

METHODS

During March and June 2018, 129 patients who received entecavir were switched to tenofovir alafenamide. Every 3- 6 months for 1 year before and after switching to tenofovir alafenamide, all patients underwent measurements of HBsAg, hepatitis core-related antigen (HBcrAg), calcium (Ca), inorganic phosphorus, and estimated glomerular filtration rate (eGFR).

RESULTS

The percent decline rate during the entecavir and tenofovir alafenamide phases at 6 months were 2.38% (-3.57 to 0.00) and -3.57% (-7.14 to 0.00), respectively, and those at 12 months were 3.03% (-6.57 to 0.00) and -5.56% (-7.41 to -2.50), respectively. HBsAg levels were reduced significantly more during the tenofovir alafenamide phase than during the entecavir phase (P < 0.0001). There were no significant differences in the percent declines of HBcrAg, Ca, inorganic phosphorus, or eGFR during the entecavir and tenofovir alafenamide phases after 1 year.

CONCLUSION

tenofovir alafenamide significantly decreased HBsAg levels compared to entecavir.

Bone and renal safety profile at 72 weeks after switching to tenofovir alafenamide in chronic hepatitis B patients

Background and Aim

Tenofovir disoproxil fumarate (TDF) has been efficacious in treating chronic hepatitis B (CHB), but long-term use is accompanied by a decline in renal function and bone mineral density (BMD). Tenofovir alefanamide (TAF) is a prodrug of tenofovir, with similar efficacy in CHB but with fewer side effects than TDF. Recent studies on patients who underwent the switch from TDF to TAF have shown improved bone and renal profiles from 24 to 48 weeks of follow-up.

Methods

This study provides follow-up at 72 weeks in a real-world cohort of 61 Asian CHB patients who were switched from TDF to TAF. All patients had been treated with TDF for at least 12 months with hepatitis B virus DNA <21 IU/mL prior to switch.

Results

Improvements in proximal tubular function, measured by urine beta-2-microglobulin to creatinine and retinol-binding protein to creatinine ratios, were sustained at 72 weeks (P < 0.01). Renal function showed decline at 72 weeks compared to baseline (GFR_CG 90.9 vs 96.3 mL/min, P < 0.01). Improvement in hip BMD was sustained at 72 weeks (mean % change of 17.7% from baseline, P < 0.01). However, spine BMD showed discordance, with initial improvement at 24 weeks (3.3% from week 0, P < 0.01) but regression at 72 weeks (-0.6% from week 0, P = NS). Interestingly, there was a slight increase in weight and BMI after 72 weeks (P < 0.01).

Conclusions

CHB patients who switch from long-term TDF to TAF therapy show sustained improvement in proximal tubular function and hip BMD. Weight gain was noted, and long-term studies are needed to evaluate its effect on patient outcomes.

Switching to tenofovir disoproxil fumarate in entecavir-treated chronic hepatitis B patients: A pilot randomized controlled study

Although hepatitis B surface antigen (HBsAg) removal is considered the goal of chronic hepatitis B treatment, it can rarely be achieved with nucleos(t)ide analogues (NAs). It has been reported that tenofovir disoproxil fumarate (TDF) is superior in reducing HBsAg compared with entecavir (ETV) in treatment-naïve patients; however, the effect of TDF in patients who have received NAs is still unclear. The aim of the present study was to evaluate the efficacy of switching from ETV to TDF in patients who were already receiving ETV. A pilot randomized controlled study for 2 years in patients who had been treated with ETV for >1 year and did not exhibit drug resistance was performed (Clinical trial registration: UMIN000021948, UMIN-CTR, May 1, 2016). A total of 20 patients were enrolled and 19 patients were randomized into 2 groups, a TDF-switching group (n=12) or an ETV-continuing group (n=7). The mean change in HBsAg levels after 2 years was greater in the TDF group compared with the ETV group, but the difference was not significant (-0.25 vs. -0.06 log IU/ml). In the TDF group, hepatitis B e antigen (HBeAg)-positive patients at baseline showed significantly greater changes in HBsAg (-0.63 vs. -0.03 log IU/ml; P=0.030). In contrast, no difference between HBeAg-positive and HBeAg-negative patients was observed in the ETV group. No significant differences of estimated glomerular filtration rate and inorganic phosphorus changes were observed among the TDF and ETV groups. In conclusion, a significant HBsAg decrease was not achieved after switching from ETV to TDF in the overall analysis, but HBeAg-positive patients showed a larger HBsAg decrease after switching treatment.

Short-term efficacy after switching from adefovir dipivoxil and tenofovir disoproxil fumarate therapy to tenofovir alaferamide for chronic hepatitis B

The aim of the present study was to evaluate the effects of switching to tenofovir alafenamide (TAF) in patients who had received a nucleos(t)ide analog (NA) for the treatment of chronic hepatitis B (CHB). The data from 33 Japanese patients with CHB who received TAF therapy after using NA [adefovir dipivoxil (ADV) and/or tenofovir disoproxil fumarate (TDF)] were retrospectively analyzed. Specifically, the biochemical and virological markers from the start of the TAF treatment to 6 months later were assessed. Comparative evaluation was performed by dividing patients into two groups: Long-term (n=19) and short-term administration groups (n=14), with a cutoff administration duration of 10 years. In all 33 patients, the levels of serum hepatitis B surface antigen (HBsAg; 1,126±1,724 to 1,001±1,591 IU/ml; P<0.0001), serum alkaline phosphatase (ALP) (320±126 to 283±124 U/l; P=0.028), serum bone specific alkaline phosphatase (19.7±9.0 to 17.7±8.0 µg/l; P=0.0006) and urine β2-microglobulin-creatinine ratio (U-BMG/Cr; 5,224±17,471 to 3,547±14,652 µg/g·Cre; P=0.002) significantly decreased from baseline after 6 months. Serum HBsAg, serum ALP and U-BMG/Cr showed a significant reduction in both groups. In conclusion, switching from ADV or TDF to TAF resulted in a decrease in serum HBsAg and improvement in serum ALP and U-BMG/Cr after 6 months of treatment in patients regardless of history of treatment with NA.

Potential Anti-SARS-CoV-2 Therapeutics That Target the Post-Entry Stages of the Viral Life Cycle: A Comprehensive Review

The coronavirus disease-2019 (COVID-19) pandemic continues to challenge health care systems around the world. Scientists and pharmaceutical companies have promptly responded by advancing potential therapeutics into clinical trials at an exponential rate. Initial encouraging results have been realized using remdesivir and dexamethasone. Yet, the research continues so as to identify better clinically relevant therapeutics that act either as prophylactics to prevent the infection or as treatments to limit the severity of COVID-19 and substantially decrease the mortality rate. Previously, we reviewed the potential therapeutics in clinical trials that block the early stage of the viral life cycle. In this review, we summarize potential anti-COVID-19 therapeutics that block/inhibit the post-entry stages of the viral life cycle. The review presents not only the chemical structures and mechanisms of the potential therapeutics under clinical investigation, i.e., listed in clinicaltrials.gov, but it also describes the relevant results of clinical trials. Their anti-inflammatory/immune-modulatory effects are also described. The reviewed therapeutics include small molecules, polypeptides, and monoclonal antibodies. At the molecular level, the therapeutics target viral proteins or processes that facilitate the post-entry stages of the viral infection. Frequent targets are the viral RNA-dependent RNA polymerase (RdRp) and the viral proteases such as papain-like protease (PLpro) and main protease (Mpro). Overall, we aim at presenting up-to-date details of anti-COVID-19 therapeutics so as to catalyze their potential effective use in fighting the pandemic.

Validation of hepatocellular carcinoma risk scores in Japanese chronic hepatitis B cohort receiving nucleot(s)ide analog

BACKGROUND AND AIM

The prediction of hepatocellular carcinoma (HCC) development during nucleotide/nucleoside analog (NA) therapy is clinically important in patients with chronic hepatitis B. Although several useful models for HCC prediction have been previously reported, their usefulness in the Japanese population is unclear. Therefore, this study examines the applicability of these models in Japanese patients.

METHODS

Four hundred forty-three patients with no history of HCC who were treated with entecavir, tenofovir alafenamide, or tenofovir disoproxil fumarate were enrolled. PAGE-B, modified-PAGE-B, and REACH-B scores were calculated, and subsequent HCC development was investigated.

RESULTS

The mean follow-up duration was 5.1 years, and a total of 33 patients (7.4%) developed HCC during the follow-up period. Multivariate analysis revealed that old age (hazard ratio [HR] 1.05, 95% confidence interval [CI] 1.01-1.09, P = 0.011), male gender (HR 2.62, 95% CI 1.06-6.49, P = 0.037), and low platelet count (HR 0.83, 95% CI 0.77-0.91, P < 0.001) were independent predictors of HCC development. These factors are the same as the factors identified in the PAGE-B model. Time-dependent area under the receiver operating characteristic (AUROC) curve revealed that the AUROCs for 3 and 7 years of PAGE-B (AUROC: 0.786 and 0.744 at 3 and 7 years, respectively) were continuously higher than those of REACH-B (0.658 and 0.543) and modified PAGE-B AUROC (0.772 and 0.731).

CONCLUSIONS

PAGE-B, which can easily identify high-risk cases, can be useful for predicting HCC development in Japanese patients treated with NA therapy.

An expert review on the use of tenofovir alafenamide for the treatment of chronic hepatitis B virus infection in Asia

Asia has intermediate-to-high prevalence and high morbidity of hepatitis B virus (HBV) infection. The use of guideline-recommended nucleos(t)ide analogs with high barrier to resistance, such as entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF), is one of the key interventions for curbing HBV infection and associated morbidity in Asia. However, there are some challenges to the use of ETV and TDF; while ETV is associated with high resistance in lamivudine (LAM)-exposed (especially LAM-refractory) patients; bone and renal safety issues are a major concern with TDF. Hence, a panel of twenty-eight expert hepatologists from Asia convened, reviewed the literature, and developed the current expert opinion-based review article for the use of TAF in the resource-constrained settings in Asia. This article provides a comprehensive review of two large, phase 3, double-blind, randomized controlled trials of TAF versus TDF in HBeAg-negative (study 0108) and HBeAg-positive (study 0110) chronic HBV patients (> 70% Asians). These studies revealed as follows: (1) non-inferiority for the proportion of patients who had HBV DNA < 29 IU/mL; (2) significantly high rate of normalization of alanine aminotransferase levels; (3) no incidence of resistance; and (4) significantly better bone and renal safety, with TAF vs. TDF up to 144 weeks. Considering the benefits of TAF, the expert panel proposed recommendations for optimizing the use of TAF in Asia, along with guidance on specific patient groups at risk of renal or bone disease suitable for TAF therapy. The guidance provided in this article may help clinicians optimize the use of TAF in Asia.

Detectable HBV DNA during nucleos(t)ide analogues stratifies predictive hepatocellular carcinoma risk score

Nucleos(t)ide analogs (NA) suppress hepatitis B virus (HBV) replication and reduce the risk of hepatocellular carcinoma (HCC). However, NA cannot suppress carcinogenesis completely in patients with chronic hepatitis B. The aims of this study were to identify risk factors for HCC and develop a refined carcinogenesis prediction model. Patients receiving NA therapy (n = 1,183) were recruited retrospectively from the 16 hospitals. All patients had been receiving NA continuously for more than 1 year until the end of the follow-up. During a median follow-up of 4.9 (1.0–12.9) years, 52 (4.4%) patients developed HCC. A multivariate analysis revealed that male gender, older age, lower platelet counts at the baseline, and detectable HBV DNA during NA therapy were independent predictive factors of HCC development. The PAGE-B score was calculated by using these factors. 240 (20.3%), 661 (55.9%), and 282 (23.8%) patients were classified into low-, intermediate-, and high-risk groups, respectively. In the intermediate- and high-risk group, detectable HBV DNA was significantly associated with a higher risk of HCC development compared with continuously undetectable HBV DNA, respectively (HR 3.338; 95% CI 1.045–10.66/HR 3.191; 95% CI 1.543–6.597). PAGE-B–DNA, which is the combined PAGE-B and HBV DNA status, was valuable for a more refined stratification of PAGE-B.

Tenofovir alafenamide after switching from entecavir or nucleos(t)ide combination therapy for patients with chronic hepatitis B

BACKGROUND AND AIMS

Tenofovir alafenamide (TAF) has been newly approved for the treatment of chronic hepatitis B (CHB). We aimed to assess the effectiveness and renal safety of switching from entecavir (ETV) or nucleos(t)ide analogue (NA) combination therapy to TAF.

METHODS

This multicentre, retrospective, cohort study included 313 consecutive CHB patients who switched to TAF monotherapy after treatment with ETV or a nucleos(t)ide analogue (NA) combination for over 2 years. Virological/laboratory responses were evaluated for 48 weeks after switchover. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate (eGFR) <60 mL/min/1.73 m² . Differences in longitudinal parameters were compared by the generalized estimating equation method.

RESULTS

In the prior ETV group (n = 191), the HBV DNA suppression rate at week 48 was significantly increased, from 75.9% to 96.9% (P < .001). Additionally, mean changes in the HBsAg level at week 48 in HBsAg ≥ 3.0 logIU/mL and < 3.0 logIU/mL groups were -0.09 and -0.13 logIU/mL respectively. In the prior NA combination group (n = 122), the mean changes in HBsAg level at week 48 in the HBsAg ≥ 3.0 logIU/mL and <3.0 logIU/mL groups were -0.08 and -0.11 logIU/mL respectively. For patients with CKD, the eGFR at week 48 was significantly improved compared to those with non-CKD (adjusted slope coefficient difference: 2.75 mL/min/1.73 m² /48 weeks; P = .001).

CONCLUSIONS

Switching from ETV or an NA combination to TAF was effective for HBV suppression and continued HBsAg reduction. Moreover, the renal glomerular function of patients in the prior NA combination group with CKD was significantly improved compared to those with non-CKD.

LAY SUMMARY

Nucleos(t)ide analogues, such as entecavir, tenofovir disoproxil fumarate and tenofovir alafenamide, inhibit hepatitis B virus (HBV) replication and are recommended as first-line oral agents for chronic HBV infection. We evaluated the virological/biochemical effects and renal safety when patients are switched from entecavir or nucleoside-nucleotide analogue combination therapy to tenofovir alafenamide. Our findings suggest that switching to tenofovir alafenamide was effective for HBV suppression and the improvement in renal function for patients with chronic kidney disease.

Comparison of medication adherence and satisfaction between entecavir and tenofovir alafenamide therapy in chronic hepatitis B

Adherence to nucleotide/nucleoside analog therapy is important in improving prognosis in chronic hepatitis B. We aimed to compare medical adherence and satisfaction with entecavir (ETV) and tenofovir alafenamide (TAF) and to assess the effect of switching from ETV to TAF. Patients taking ETV (n = 114) and TAF (n = 35), and who switched from ETV to TAF (n = 15) were included. Medication adherence and satisfaction were assessed using a questionnaire. There was no significant difference in adherence between the ETV and TAF groups, but the medication satisfaction rates (0-10, prefer-dislike) were 1.72 ± 2.2 and 0.69 ± 1.5, respectively (P = .01; significantly higher in the TAF group). In patients who switched from ETV to TAF, medication adherence significantly improved (P = .04) as follows: never forgetting, from 40% to 87%; forgetting once every 2 to 3 months, from 33% to 7%; forgetting once every 2 months, from 20% to 7%, and forgetting once every 4 weeks, from 7% to 0%. Similarly, the medication satisfaction rate significantly improved from 4.53 ± 3.2 to 1.27 ± 2.4 after switching (P = .008). In conclusion, switching from ETV to TAF can be a useful approach to improve medication adherence and satisfaction.

Safety, efficacy, and pharmacokinetics of pradefovir for the treatment of chronic hepatitis B infection

BACKGROUND & AIMS

Pradefovir is a liver targeted novel prodrug of adefovir (PMEA) developed to provide higher antiviral activity with reduced systemic toxicities. This study evaluated the tolerability, pharmacokinetics, and antiviral activity of pradefovir in patients with chronic hepatitis B (CHB) virus infection.

METHODS

Non-cirrhotic, treatment-naïve subjects with CHB were divided into five groups (10 patients each) and randomized within each group in a ratio of 6:2:2 to receive an ascending dose of 30, 60, 75, 90, or 120 mg pradefovir, 10 mg adefovir dipivoxil (ADV), or 300 mg tenofovir disoproxil fumarate (TDF) once a day for 28 days.

RESULTS

A total of 51 subjects were randomized and 49 subjects completed the study. The groups were well matched and included 39 males, of whom 71% were hepatitis B e-antigen-negative with a mean hepatitis B virus (HBV) DNA level of 6.4-7.16 log10 IU/mL. No subject experienced a serious adverse event or nephrotoxicity. The most frequently reported adverse event was asymptomatic reduction in blood cholinesterase levels in the pradefovir group which recovered without any treatment about 13 ± 7 days after drug discontinuation. This adverse event was not observed in the ADV and TDF groups. The mean changes in serum HBV DNA were -2.78, -2.77, -3.08, -3.18, -3.44, -2.34, and -3.07 log10 IU/mL at 30, 60, 75, 90, and 120 mg pradefovir, 10 mg ADV and 300 mg TDF, respectively, with plateau levels reached with 60 mg pradefovir. Pradefovir and its metabolite PMEA showed linear pharmacokinetics proportional to the dose. The half-life of PMEA in the pradefovir group was 11.47-17.63 h.

CONCLUSIONS

Short-term use of pradefovir was well tolerated. A decline in HBV DNA levels was superior to TDF at higher doses of pradefovir. 30-60 mg pradefovir is recommended for CHB treatment.

CLINICAL TRIAL NUMBER

CTR20150224.

Hepatitis B surface antigen reduction as a result of switching from long-term entecavir administration to tenofovir

Background and Aim

Loss of hepatitis B surface antigen (HBsAg) is an important goal in the treatment of chronic hepatitis B. We investigated whether switching from long‐term entecavir (ETV) administration to tenofovir (TFV) (tenofovir alafenamide [TAF] or tenofovir disoproxil fumarate [TDF]) could contribute to the reduction of HBsAg levels.

Methods

The degree of HBsAg reduction by 48 weeks in 30 patients following switching from ETV to TFV was compared with results from 147 patients who continued ETV as a control.

Results

TFV group switched to TFV after mean 6.79 years of ETV administration. HBV‐DNA levels remained below 1.0 log IU/mL in all cases in both groups during 48 weeks. Median HBsAg reduction at 48 weeks was 0.075 (−0.05 to 0.38) log/IU/mL in the TFV switch group, and 0.070 (−0.28 to 0.50) in the ETV continuation group, which was not statistically significant (p = 0.5). In a subgroup of hepatitis B e antigen negative patients whose HBsAg had not been reduced (HBsAg reduction ≤0 log IU/mL) in the 48 weeks prior to entry into the study, HBsAg reduction was significantly higher in the TFV switch group than in the ETV continuation group (0.15 [0.07–0.135] in TFV, 0.09 [−0.14 to 0.25] log IU/mL in ETV, p = 0.04).

Conclusion

Although HBsAg reduction is equivalent with ETV continuation and switching to TFV in all patients at 48 weeks, switching from ETV to TFV could provide an alternative therapeutic strategy toward HBsAg elimination in a specific subpopulation of patients.