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

Availability, price, and affordability of anti-hepatitis B virus drugs: a cross-sectional study in China

BACKGROUND

The global prevalence of hepatitis B virus (HBV) has presented a persistent challenge for public health prevention and treatment. However, studies that assess the public's access to anti-HBV drugs are absent.

AIM

To examine the availability, pricing, and affordability of anti-HBV drugs in Jiangsu province, China and provide recommendations for improvement.

METHOD

An enhanced methodology developed by the World Health Organization (WHO) and Health Action International was applied in a cross-sectional study that included 1026 healthcare facilities distributed in 13 prefectural-level cities in Jiangsu province.

RESULTS

Since almost all drugs had an availability of less than 30%, the accessibility of anti-HBV drugs was notably low. Primary healthcare facilities had the lowest availability, reporting 1.4% for Original Brands (OBs) and 1.7% for lowest-priced generics (LPGs). Furthermore, the northern Jiangsu region recorded the lowest availability at 0.7%. LPGs demonstrated higher availability than OBs, with median availability probabilities of 2.6% and 1.4%, respectively. The drugs listed on the WHO Essential Medicines List exhibited higher availability than those on other lists. The median price ratios for OBs, LPGs, and volume-based purchasing drugs were 0.83, 0.50, and 0.27, respectively, less than 1.5 times the international reference price. Despite favorable pricing, affordability rate was 23% for urban residents and 0% for rural residents, which was discouraging.

CONCLUSION

Low availability and affordability of anti-HBV drugs were observed. Policy recommendations should emphasize the improvement of LPG availability by incentivizing priority prescribing. Healthcare subsidies should be provided more effectively and equitably.

Preventing viral relapse with prophylactic tenofovir in hepatitis B carriers receiving chemotherapy: a phase IV randomized study in Taiwan

BACKGROUND AND AIMS

This study aimed to compare the efficacy of shorter vs. longer tenofovir disoproxil fumarate (TDF) prophylaxis in preventing hepatitis B virus (HBV) relapse in cancer patients with chronic hepatitis B (CHB) undergoing chemotherapy.

METHODS

This phase IV, prospective randomized trial enrolled cancer patients with CHB from 2014 to 2019 in Taiwan. Included patients were randomized to receive either 24- (Arm A) or 48-week (Arm B) post-chemotherapy TDF and compared for cumulative incidence of virological and clinical relapse. Logistic regressions were conducted to determine the factors associated with HBV relapse.

RESULTS

One hundred patients were randomized, and 41 patients in Arm A and 46 in Arm B completed the TDF treatment. No significant difference was found in cumulative incidence of virological relapse (Arm A: 94.4%, Arm B: 93.1%, p = 0.110) or clinical relapse among patients with baseline HBV DNA > 2000 IU/mL (Arm A: 38.9%, Arm B: 26.7%, p = 0.420) between the two arms. High baseline HBV DNA ≥ 10,000 IU/mL (OR = 51.22) and HBsAg ≥ 1000 IU/mL (OR = 8.64) were independently associated with an increased virological relapse. Alanine aminotransferase (ALT), serum phosphorus, vitamin D, and estimated glomerular filtration rate (eGFR) remained stable throughout the study.

CONCLUSIONS

The 24-week preventative TDF has comparable efficacy to the 48-week treatment in virologic and clinical relapse. High baseline HBsAg or HBV DNA is associated with a higher risk of HBV relapse. These findings imply a 24-week duration of TDF treatment with a close monitor for patients with a high baseline viral load. Hepatitis B virus infection is a prominent cause of liver cancer and chronic liver disease and affected millions of people worldwide. When HBV-infected people are exposed to immunosuppressive medication or chemotherapy for cancer, the chance of HBV reactivation rises considerably. This trial showed 24-week tenofovir disoproxil fumarate (TDF) may be sufficient for preventing HBV relapse in cancer patients receiving chemotherapy.

CLINICAL TRIAL REGISTRATION NUMBER

NCT02081469.

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.

Evaluate the clinical efficacy of traditional Chinese Medicine as the neoadjuvant treatment in reducing the incidence of hepatocellular carcinoma in patients with hepatitis B-related cirrhosis: A systematic review and meta-analysis

Background

Traditional Chinese Medicine (TCM), has been used for hepatocellular carcinoma (HCC) at every therapeutic stage, even before tumor formation. However, the efficacy of TCM in reducing the incidence of HCC in patients with chronic hepatitis B-related cirrhosis remains unclear. This study aims to address this gap.

Methods

Publications were collected from PubMed, EMBASE, Cochrane Library, Web of Science, CNKI, Sino Med, VIP, and Wan Fang Databases. Relative risk (RR) was calculated with a 95 % confidence interval (CI). Heterogeneity was assessed. The Cochrane Collaboration's tool was used to assess the risk of bias.

Results

10 studies with 2702 patients showed that the combination therapy significantly reduced the incidence of HCC in patients with post-hepatitis B cirrhosis at 1, 3, and 5 years. However, the preventive effects of TCM were in compensated cirrhosis, but not the decompensated cirrhosis. Furthermore, TCM correlated with improved liver function and enhanced virological response.

Conclusion

Combination therapy with TCM demonstrated the certain potential in reducing the incidence of HCC in patients with hepatitis B cirrhosis. This is attrinuted to the improvement of liver function and enhancement of the viral response. However, the efficacy of TCM in the field still needs more high-quality RCTs to provide stronger evidence in the future.

MDSC-targeted liposomal all-trans retinoic acid suppresses mMdscs and improves immunotherapy in HBV infection

BACKGROUND

Myeloid-derived suppressor cells (MDSCs) are evolving as a prominent determinant in cancer occurrence and development and are functionally found to suppress T cells in cancer. Not much research is done regarding its involvement in viral infections. This research was designed to investigate the role of MDSCs in hepatitis B virus (HBV) infection and how targeting these cells with our novel all-trans retinoic acid encapsulated liposomal formulation could improve immunotherapy in C57BL/6 mice.

METHODS

Ten micrograms (10 μg) of plasmid adeno-associated virus (pAAV/HBV 1.2, genotype A) was injected hydrodynamically via the tail vein of C57BL/6 mice. An all-trans retinoic acid encapsulated liposomal formulation (L-ATRA) with sustained release properties was used in combination with tenofovir disoproxil fumarate (TDF), a nucleotide analog reverse transcriptase inhibitor (nRTI) to treat the HBV infection. The L-ATRA formulation was given at a dose of 5 mg/kg intravenously (IV) twice a week. The TDF was given orally at 30 mg/kg daily.

RESULTS

Our results revealed that L-ATRA suppresses MDSCs in HBV infected mice and enhanced T-cell proliferation in vitro. In vivo studies showed higher and improved immunotherapeutic effect in mice that received L-ATRA and TDF concurrently in comparison with the groups that received monotherapy. Lower HBV DNA copies, lower concentrations of HBsAg and HBeAg, lower levels of ALT and AST and less liver damage were seen in the mice that received the combination therapy of L-ATRA + TDF.

CONCLUSIONS

In effect, targeting MDSCs with the combination of L-ATRA and TDF effectively reduced mMDSC and improved immunotherapy in the HBV infected mice. Targeting MDSCs could provide a breakthrough in the fight against hepatitis B virus infection.

Estimated glomerular filtration rate partially recovered in patients without Hypertriglyceridemia during Tenofovir disoproxil fumarate treatment

BACKGROUND

Decrease in estimated glomerular filtration rate (eGFR) during Tenofovir disoproxil fumarate (TDF) treatment remains a concern, and few patients experience partial recovery of eGFR. This study aimed to investigate the risk factors for eGFR recovery in patients with and without hypertriglyceridemia.

METHODS

A total of 203 patients with chronic HBV infection were prospectively recruited and followed up for three years. Data were collected at baseline, first, second, and third years during TDF treatment.

RESULTS

Most patients achieved normal ALT (80.0% vs. 82.5%) and undetectable HBV DNA (95.0% vs. 95.6%) in both groups (p > 0.05). For patients with hypertriglyceridemia, eGFR and cholesterol did not change significantly during the 3-year follow-up, while triglyceride (TG) decreased significantly in the first year and persisted at a lower level in the subsequent two years. For patients without hypertriglyceridemia, eGFR declined significantly in the first year of treatment, then gradually recovered during the subsequent two years, and eGFR was negatively correlated with TG at the four time points. Fifteen (15/183, 8.2%) patients without hypertriglyceridemia experienced eGFR partial recovery in the third year. Univariate and multivariate analyses showed that baseline eGFR <90 mL/(min·1.73 m²) (p < 0.01; 95% CI: 0.019-0.284) and age (p < 0.01; 95% CI: 0.817-0.960) were independent risk factors for eGFR recovery.

CONCLUSION

eGFR partially recovered in patients without hypertriglyceridemia during TDF treatment, and TG regulation might be a useful strategy to hinder renal function decline, although larger, confirmatory studies are necessary to validate our findings.Key messagesFor patients with normal triglyceride, eGFR declined significantly at the first year of TDF treatment, then gradually recovered during the subsequent two years, and eGFR was negatively correlated with TG. Baseline eGFR <90 mL/(min·1.73 m²) and age were independent risk factors for eGFR recovery.

Current practice and recommendations for management of hepatitis B virus in people living with HIV in Asia

BACKGROUND

The prevalence of HIV and hepatitis B virus (HBV) co-infection is higher in Asia than in Europe and North America and varies significantly between different regions within Asia. Important routes of transmission of both these infections include high-risk unprotected sexual contact, intravenous drug use, and transmission of maternal infection perinatally or in early childhood. While life expectancy among people living with HIV has been extended with effective antiretroviral therapy (ART), HBV-induced liver injury and complications have emerged as a leading cause of morbidity and mortality in people living with HIV.

OBJECTIVES

This article describes the prevalence of co-infection, current clinical practice, and recommendations for the management of people living with HIV-HBV co-infection in Asia.

RESULTS AND CONCLUSIONS

Screening for HBV should occur at the time of HIV diagnosis; however, HBV screening rates in people living with HIV in Asia vary widely by region. Similarly, people with HBV should be screened for HIV before initiation of HBV antiviral therapy. People with HIV-HBV co-infection should be assessed for liver damage and risk factors for liver disease and be monitored regularly for liver complications and HBV DNA. Medical treatment with ART is lifelong and includes tenofovir and lamivudine or emtricitabine, unless intolerant or contraindicated, as these are active against both HIV and HBV. HBV vaccination programmes are effective in reducing co-infection rates. Mother-to-child transmission can be prevented through measures such as vaccination, antenatal screening, and treatment of pregnant women who are infected.

Development of Therapy Based on the Exploration of Biological Events Underlying the Pathogenetic Mechanisms of Chronic Hepatitis B Infection

According to the World Health Organization (WHO), an estimated 296 million people are chronically infected with hepatitis B virus (HBV). Approximately 15-25% of these people develop complications such as advanced chronic liver diseases (ACLDs). Mortality due to HBV-related complications accounted for an estimated 882,000 deaths in 2019. Potent preventive vaccines have already restricted new HBV infections, and several drugs are available to treat chronic HBV infections. However, the positive impacts of these drugs have been recorded in only a few patients with chronic HBV infection. These drugs do not show long-term efficacy and cannot halt the progression to complications. Thus, more effective and evidence-based therapeutic strategies need to be urgently developed for patients with chronic HBV infection. CHB is a pathological entity induced by HBV that progresses due to impaired host immunity. This indicates the inherent limitations of antiviral-drug-based monotherapy for treating patients with chronic HBV infection. Additionally, commercially available antiviral drugs are not available to patients in developing and resource-constrained countries, posing a challenge to achieving the following WHO goal: "Elimination of Hepatitis by 2030". As such, this review aimed to provide insights regarding evidence-based and effective management strategies for chronic HBV infection.

First year real life experience with tenofovir alafenamide fumarate: The pythagorean cohort

Background and Aim

In chronic hepatitis B infection, antiviral therapy significantly reduces the incidence of complications. This study aimed to present real-life 12-month effectiveness and safety data for TAF.

Materials and Methods

This Pythagoras Retrospective Cohort Study included patients from 14 centers in Turkiye. The study presents 12-month results of 480 patients treated with TAF as initial therapy or after switching from another antiviral drug.

Results

The study shows treatment of about 78.1% patients with at least one antiviral agent (90.6% tenofovir disoproxil [TDF]). The rate of undetectable HBV DNA increased in both treatment-experienced and naive patients. In TDF-experienced patients, the rate of alanine transaminase (ALT) normalization increased slightly (1.6%) within 12 months, but the change was not statistically significant (p=0.766). Younger age, low albumin, and high body mass index and cholesterol were identified as risk factors for abnormal ALT after 12 months, but no linear relationship was detected. In TDF-experienced patients, renal and bone function indicators showed significant improvement three months after the transition to TAF and remained stable for 12 months.

Conclusion

Real-life data demonstrated effective virological and biochemical responses with TAF therapy. After switching to TAF treatment, gains in kidney and bone functions were achieved in the early period.

Expanding antiviral therapy indications for HBeAg-negative chronic hepatitis B patients with normal ALT and positive HBV DNA

With the improved efficacy and accessibility of antiviral agents as well as the concerns about disease progression, there is a hot discussion on whether HBeAg-negative chronic hepatitis B (CHB) patients with normal alanine aminotransferase (ALT) and positive HBV DNA should be treated. According to the international guidelines on the stages of the natural history of HBV infection, HBeAg-negative CHB patients with normal ALT and positive HBV DNA can be divided into two groups: one is the well-known "inactive carrier phase", which is defined as serum HBV DNA < 2000 IU/ml and no significant liver inflammation; and the other is the "indeterminate phase", which is defined as serum HBV DNA ≥ 2000 IU/mL regardless of the pathological changes in liver tissue, or HBV DNA < 2000 IU/mL but accompanied by significant pathological changes in the liver. In this minireview, we will expound the disease characteristics, disease progression, and clinical management status of these two groups. Based on the analysis, we propose that HBeAg-negative patients with normal ALT but detectable serum HBV DNA should be treated, regardless of their age, family history of hepatocellular carcinoma (HCC) or the severity of liver necroinflammation. Expanding the indications of antiviral therapy will help improve the survival and quality of life of patients by preventing disease progression, and consequently reduce the risk of HCC development.

Virological responses to tenofovir-alafenamide-containing antiretroviral therapy in people living with HIV co-infected with lamivudine-resistant or lamivudine-susceptible hepatitis B virus

BACKGROUND

Data on the effectiveness of tenofovir alafenamide (TAF) against lamivudine-resistant (LAM-R) hepatitis B virus (HBV) among patients co-infected with human immunodeficiency virus (HIV) and HBV are limited.

METHODS

Between April and December 2018, HIV-positive patients co-infected with LAM-R or lamivudine-susceptible (LAM-S) HBV who switched from tenofovir-disoproxil-fumarate-containing antiretroviral therapy (ART) to TAF-containing ART were followed for 96 weeks. Plasma HBV and HIV loads, HBV serological markers, and liver function before and after the switch were analysed.

RESULTS

In total, 182 patients co-infected with HIV and HBV were included in this study: 45 with LAM-R HBV and 137 with LAM-S HBV. At baseline, 28.9% and 7.4% of patients in the LAM-R and LAM-S groups, respectively, tested positive for hepatitis B virus envelope antigen (HBeAg) (P<0.001), and the respective percentages of patients who had achieved plasma HBV DNA <20 IU/mL were 95.5% and 97.1%. At weeks 48 and 96, 100% and 94.9% of patients in the LAM-R group, respectively, and 97.1% and 95.6% of patients in the LAM-S group, respectively, maintained plasma HBV DNA <20 IU/mL. Lamivudine resistance of HBV and baseline hepatitis B virus surface antigen (HBsAg) level were associated with HBsAg decrement at week 96 at a degree of 0.25 log₁₀ IU/mL [95% confidence interval (CI) 0.059-0.246] and 0.22 log₁₀ IU/mL (per 1-log₁₀IU/mL increase, 95% CI 0.018-0.101), respectively. At week 96, 2.2% (4/182) of patients had HBsAg loss; no patients in the LAM-R group and 25.0% (2/8) of patients in the LAM-S group had HBeAg seroconversion.

CONCLUSIONS

Switching to TAF-containing regimens maintained high rates of HBV viral suppression in patients co-infected with either LAM-R or LAM-S HBV. The decrease in HBsAg was minimal, and HBsAg seroconversion occurred infrequently.

Development of Therapeutic Vaccine for Chronic Hepatitis B: Concept, Cellular and Molecular Events, Design, Limitation, and Future Projection

Four decades have passed since the first usage of the therapeutic vaccine in patients with chronic hepatitis B (CHB). However, there is no approved regimen of vaccine therapy for the treatment of CHB. This is mainly attributable to faulty conception, an improper understanding of the cellular and molecular mechanisms of CHB, and the impaired design of vaccine therapy for CHB. With the advent of new techniques and a better understanding of cellular and molecular mechanisms underlying the genesis of CHB, the limitations and failures of previous regimens of therapeutic vaccines have been primarily understood. Additionally, the importance of immune therapy for treating millions of CHB patients and achieving the target of "Elimination of Hepatitis by 2030" has been focused on in the international arena. This has been amplified by the apparent limitation of commercially available antiviral drugs that are infinite in duration, endowed with safety concerns, and unable to cure liver damage due to their minimal immune modulation capacities. The proposed review article comprehensively discusses each of these points and proposes evidence-based approaches for viable types of vaccine therapy for the treatment of CHB.

Advances in Immunotherapy for Hepatitis B

Hepatitis B virus (HBV) is a hepatotropic virus with the potential to cause chronic infection, and it is one of the common causes of liver disease worldwide. Chronic HBV infection leads to liver cirrhosis and, ultimately, hepatocellular carcinoma (HCC). The persistence of covalently closed circular DNA (cccDNA) and the impaired immune response in patients with chronic hepatitis B (CHB) has been studied over the past few decades. Despite advances in the etiology of HBV and the development of potent virus-suppressing regimens, a cure for HBV has not been found. Both the innate and adaptive branches of immunity contribute to viral eradication. However, immune exhaustion and evasion have been demonstrated during CHB infection, although our understanding of the mechanism is still evolving. Recently, the successful use of an antiviral drug for hepatitis C has greatly encouraged the search for a cure for hepatitis B, which likely requires an approach focused on improving the antiviral immune response. In this review, we discuss our current knowledge of the immunopathogenic mechanisms and immunobiology of HBV infection. In addition, we touch upon why the existing therapeutic approaches may not achieve the goal of a functional cure. We also propose how combinations of new drugs, and especially novel immunotherapies, contribute to HBV clearance.

Efficacy and Renal Safety of Prophylactic Tenofovir Alafenamide for HBV-Infected Cancer Patients Undergoing Chemotherapy

There are no data comparing the efficacy and safety of prophylactic entecavir (ETV), tenofovir disoproxil fumarate (TDF) and tenofovir alafenamide (TAF) for HBV-infected cancer patients undergoing chemotherapy. This study aimed to compare the efficacy and renal safety of ETV, TDF and TAF in this setting. HBsAg-positive cancer patients treated with ETV (n = 582), TDF (n = 200) and TAF (n = 188) during chemotherapy were retrospectively enrolled. Antiviral efficacy and risk of renal events were evaluated. The rate of complete viral suppression at 1 year was 94.7%, 94.7% and 96.1% in ETV, TDF and TAF groups, respectively (p = 0.877). A significant proportion of patients developed renal dysfunction during chemotherapy. The incidences of acute kidney injury (AKI) and chronic kidney disease stage migration were comparable among the ETV, TDF and TAF groups. TAF was relatively safe in patients with predisposing factors of AKI, including hypoalbuminemia and cisplatin use. In patients who were switched from TDF to TAF during chemotherapy, the renal function remained stable and viral suppression was well maintained after switching. In conclusion, TAF had good renal safety and comparable efficacy with ETV and TDF for HBV-infected cancer patients receiving chemotherapy. Switching from TDF to TAF during chemotherapy is safe, without a loss of efficacy.

Clinical Efficacy and Safety of Tenofovir in the Treatment of Patients with Chronic Hepatitis B

The negative rate of serum HBV DNA, HBeAg, and ALT in the tenofovir group was significantly higher than that in the entecavir group (86.67%, 3.33%, and 80.00%) (all P < 0.05). In the tenofovir group, 2cases were considered. Objective. The aim of this study is to analyze the clinical effect and safety of tenofovir in the treatment of chronic hepatitis B (CHB) patients. Methods. A total of 60 patients with CHB who were admitted and treated in Anqing First People's Hospital Affiliated to Anhui Medical University from January 2019 to July 2020 were randomly assigned at a ratio of 1 : 1 into the tenofovir group (treated with tenofovir) and the entecavir group (treated with entecavir) via the random number table method. The clinical therapeutic effect and safety of the two groups were compared. Results. The serum hepatitis B virus (HBV) DNA levels in the two groups decreased after treatment, but there was no significant difference. Ths (2.50%) had nausea, 1 (1.25%) had headache, and 0 had an elevated creatine kinase. In the tenofovir group,1(3.33%) had nausea, 0 had headache, and 0 had an elevated creatine kinase. In the entecavir group, there were 3 (10.00%) cases of nausea, 2 (6.67%) cases of headache, and 1 (3.33%) case of elevated creatine kinase. The overall incidence of adverse reactions in the tenofovir group (3.33%) was significantly lower than that in the entecavir group (20.00%) (all P < 0.05). Conclusion. Tenofovir is more effective than entecavir in the treatment of patients with CHB due to low incidence of adverse events and a good safety profile.

Prodrug Therapies for Infectious and Neurodegenerative Diseases

Prodrugs are bioreversible drug derivatives which are metabolized into a pharmacologically active drug following chemical or enzymatic modification. This approach is designed to overcome several obstacles that are faced by the parent drug in physiological conditions that include rapid drug metabolism, poor solubility, permeability, and suboptimal pharmacokinetic and pharmacodynamic profiles. These suboptimal physicochemical features can lead to rapid drug elimination, systemic toxicities, and limited drug-targeting to disease-affected tissue. Improving upon these properties can be accomplished by a prodrug design that includes the careful choosing of the promoiety, the linker, the prodrug synthesis, and targeting decorations. We now provide an overview of recent developments and applications of prodrugs for treating neurodegenerative, inflammatory, and infectious diseases. Disease interplay reflects that microbial infections and consequent inflammation affects neurodegenerative diseases and vice versa, independent of aging. Given the high prevalence, personal, social, and economic burden of both infectious and neurodegenerative disorders, therapeutic improvements are immediately needed. Prodrugs are an important, and might be said a critical tool, in providing an avenue for effective drug therapy.

Effect of switching from tenofovir disoproxil fumarate to tenofovir alafenamide on lipid profiles in patients with hepatitis B

For long-term treatment of hepatitis B virus (HBV) infection, switching from tenofovir-disoproxil-fumarate (TDF) to tenofovir-alafenamide (TAF) may prevent renal dysfunction and bone loss. However, the precise effects of this switch on the blood lipid profile remain to be clarified. This is an important issue as TDF is known to have effects on both low- and high-density lipids. Therefore, our retrospective multi-center study aimed to evaluate the effects of switching from TDF to TAF on the lipid profile of patients with HBV infection. Samples were obtained prior to the switch from TDF to TAF and at 6-12 months after TAF initiation. In some cases, additional samples obtained pre- and post-TDF administration were available for analysis. Serum cholesterol levels, including oxidized-low-density lipoprotein (LDL) and non-high-density lipoprotein-cholesterol (HDL-c), and the rate of dyslipidemia, according to the NCEP-ATP III lipid risk classification, were analyzed. The data from 69 patients were analyzed, including 33 patients with pre- and post-TDF-initiation serum samples. Total cholesterol (T-chol), HDL-c, LDL-c, non-HDL-c, and oxidized LDL levels increased significantly after switching to TAF. With regard to sequential changes pre- to post-TAF, TDF was associated with significantly lower serum T-chol, HDL-c, and oxidized LDL-c levels, with T-chol, HDL-c, LDL-c, and oxidized LDL-c levels increasing significantly after the switch. The switch from TDF to TAF was also associated with an increase in the rate of dyslipidemia, from 33% to 39%, with an increase in the rate of severe dyslipidemia of 1.4% and 5.8%, based on T-chol and LDL-c levels. Of note, no cases of severe dyslipidemia were detected pre-TAF treatment. As oxidized LDL-c and non-HDL-c are strongly associated with atherosclerosis development, careful monitoring of lipid is needed after switching from TDF to TAF in this clinical population.

Asian Pacific association for the study of liver (APASL) guidelines: hepatitis B virus in pregnancy

Hepatitis B virus (HBV) infection still remains a major public health issue in the Asia-Pacific region. Most of the burden of HBV-related disease results from infections acquired in infancy through perinatal or early childhood exposure to HBV in Asia-Pacific. Hepatitis B during pregnancy presents unique management issues for both the mother and fetus. These APASL guidelines provide a comprehensive review and recommendations based on available evidence in the literature, for the management of females with HBV infection through every stage of pregnancy and postpartum. These also address the concerns, management challenges, and required follow-up of children born to hepatitis B-positive mothers.

Safety and Efficacy of Tenofovir Alafenamide Fumarate in Early-Middle Pregnancy for Mothers With Chronic Hepatitis B

Background

Tenofovir alafenamide fumarate has been used in late pregnancy; however, no data exist regarding its safety and effectiveness in early and middle pregnancy for mothers with hepatitis B virus infection.

Aims

To design a prospective study to investigate the efficacy and safety of TAF in pregnant women with chronic HBV infection during early-middle pregnancy.

Methods

Pregnant women with active chronic hepatitis B who received tenofovir alafenamide fumarate during early and middle pregnancy were enrolled and followed up until 6 months postpartum. Infants received immunoprophylaxis. The primary endpoint was the safety of mothers and infants. The secondary endpoints were maternal hepatitis B virus DNA reduction at delivery and mother-to-child transmission rate.

Results

Among 98 mothers enrolled, 31 initiated tenofovir alafenamide fumarate in early pregnancy, and 57 in middle pregnancy. The mean (± standard deviation) age was 29.00 (±3.81) years. At delivery, 100% (98/98) of the mothers achieved hepatitis B virus DNA levels <200,000 IU/L. Ninety-eight infants were born, and none had congenital defects or malformations. All infants received hepatitis B virus immunoprophylaxis. The mother-to-child transmission rate was 0%. Growth parameters including body weight, height, and head circumference were comparable to the national standards for physical development. No severe adverse effects were reported in either mothers or infants. No severe liver function damage occurred in any of the mothers.

Conclusions

Initiating tenofovir alafenamide fumarate in early and middle pregnancy appears safe for both mothers and infants, and it is effective for controlling maternal disease as well as interrupting mother-to-child transmission.

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.

Cellular and Molecular Mechanisms Underlying Scope and Limitation of Ongoing and Innovative Therapies for Treating Chronic Hepatitis B

Millions of people of the world suffer from chronic hepatitis B (CHB), a pathological entity in which the patients are chronically infected with hepatitis B virus (HBV) and express hepatitis B surface antigen (HBsAg) and HBV DNA, as well as evidence of liver damages. Considerable numbers of CHB patients develop cirrhosis of the liver and hepatocellular carcinoma if untreated. Two groups of drugs (interferons and nucleoside analogs) are used to treat CHB patients, but both are endowed with considerable adverse effects, increased costs, extended duration of therapy, and limited efficacy. Thus, there is a pressing need to develop new and innovative therapeutics for CHB patients, and many such drugs have been developed during the last four decades. Some of these drugs have inspired considerable optimism to be a game-changer for the treatment of CHB. Here, we first discuss why ongoing therapeutics such as interferon and nucleoside analogs could not stand the test of time. Next, we dissect the scope and limitation of evolving therapies for CHB by dissecting the cellular and molecular mechanisms of some of these innovative therapeutics.

Efficacy of entecavir, tenofovir disoproxil fumarate, and tenofovir alafenamide in treatment-naive hepatitis B patients

BACKGROUND AND AIMS

Antiviral agents for chronic hepatitis B (CHB) reduced the risk of hepatocellular carcinoma (HCC) development. The outcomes of entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide (TAF) were compared in patients with CHB.

METHODS

Between 2017 and 2019, treatment-naïve patients with CHB treated with ETV, TDF, and TAF were recruited from three Korean tertiary institutes. The cumulative incidences of HCC and orthotopic liver transplantation (OLT) or mortality were calculated and compared using Kaplan-Meier analysis before and after trimatch.

RESULTS

Among recruited 2082 patients, 43 patients developed HCC, whereas 66 developed OLT or mortality. Before trimatch, the cumulative incidence of HCC was statistically similar among patients treated with three antiviral agents (p = 0.340). However, the cumulative probability of OLT or mortality development in patients treated with ETV or TDF was significantly higher than that of patients with TAF before trimatch (all p < 0.05). On multivariate analysis, male sex [hazard ratio (HR) 2.990] and older age (HR 1.044) were independently associated with an increased risk of HCC development, whereas higher platelet count (HR 0.993) was independently associated with a decreased risk (all p < 0.05). The type of antiviral agents did not significantly influence the risk of HCC and OLT or mortality development (all p > 0.05). After trimatch, no significant difference in the cumulative probability for HCC and OLT or mortality according to antiviral agents was found (all p > 0.05).

CONCLUSIONS

The outcomes of ETV, TDF, and TAF on the risk of HCC and OLT or mortality were statistically similar in treatment-naïve patients with CHB.

Exploring evidence-based innovative therapy for the treatment of chronic HBV infection: experimental and clinical

With the advent of various vaccines and antimicrobial agents during the 20th century, the control and containment of infectious diseases appeared to be a matter of time. However, studies unveiled the diverse natures of microbes, their lifestyle, and pathogenetic potentials. Since the ground-breaking discovery of the hepatitis B virus (HBV) by Baruch Blumberg and the subsequent development of a vaccine in the early 1980s, the main task of the scientific community has been to develop a proper management strategy for HBV-induced chronic liver diseases. In the early 1980’s, standard interferon (IFN) induced a reduction of HBV DNA levels, followed by the normalization of serum transaminases (alanine aminotransferase, ALT), in some chronic hepatitis B (CHB) patients. However, in the course of time, the limitations of standard IFN became evident, and the search for an alternative began. In the late 1980’s, nucleoside analogs entered the arena of CHB treatment as oral drugs with potent antiviral capacities. At the beginning of the 21st century, insights were developed into the scope and limitations of standard IFN, pegylated-IFN as well as nucleoside analogs for treating CHB. Considering the non-cytopathic nature of the HBV, the presence of covalently closed circular DNA (cccDNA) in the nucleus of the infected hepatocytes and HBV-induced immune-mediated liver damages, a new field of CHB management was initiated by modulating the hosts’ immune system through immune therapy. This review will discuss the nature and design of innovative immune therapy for CHB.

Demographics, Biochemical Characteristics, and Phases of Chronic Hepatitis B Virus Infection: Retrospective Analysis From a Secondary Care Setup

Introduction Hepatitis B virus (HBV) is the leading cause of cirrhosis in the developing world. Despite the development of effective vaccine(s) and direct-acting antivirals (DAAs) such as tenofovir and entecavir, the eradication of chronic HBV remains a distant dream in endemic regions. Factors such as treatment naivety, longer duration of disease, late diagnosis, family history of liver disorders and hepatocellular carcinoma, fatty liver disease, multiple comorbidities, alcoholism, use of tobacco products, noncompliance to drugs, and loss to follow-up all contribute to disease progression and development of complications. In order to promote a better understanding of the treatment initiation, duration, and eventual outcomes, the European Association for the Study of the Liver (EASL) updated its guidelines in 2017 and introduced a new staging system for chronic HBV. Since these guidelines are relatively recent, data regarding the new staging is virtually absent in local/regional settings. Moreover, it has been observed that patients presenting to secondary care setups at major urban centers have disease characteristics quite distinct from those of their rural counterparts or patients presenting to tertiary care setups, even in the same cities. Additionally, there is scarce published data with regard to this aspect. With this study, we hope to make progress on all of those fronts. Objective We aimed to evaluate the demographics, biochemical characteristics, and phases of chronic HBV at the secondary care level. Methods This was a retrospective observational cohort conducted at the Sindh Government Hospital, Liaquatabad from January to December 2020. Patients of either gender who were aged ≥12 years, and diagnosed as a case of chronic HBV were eligible to be enrolled in the study. Only treatment-naive patients were enrolled in the study. Demographics, biochemical characteristics, and phases of HBV (in light of the updated guidelines issued by EASL in 2017 with respect to HBV) were recorded and analyzed. Patient confidentiality was ensured at all times. Results A total of 102 patients were enrolled in the study. The mean age of our cohort was 34.31 ±12.42 years, and the male-to-female ratio was 3:2. All referrals were made from within the city district. Housewives and laborers made up the majority of our patients. The mean alanine transaminase (ALT) levels were 39.83 ±21.33 IU/L; otherwise, the biochemical profile of the patients was unremarkable. Phase III was the most frequently recorded stage of chronic HBV; 41 (40.19%) of the patients were diagnosed with it. However, nearly half of the patients had chronic active hepatitis (phases II and IV). Only a single case each of hepatitis Delta virus and decompensated liver disease (DCLD) was recorded. Conclusions All patients of chronic HBV presenting at the secondary care level were referred locally, were relatively older, and exhibited a higher frequency of chronic active hepatitis (phases II and IV). This corresponded to borderline elevations of ALT. But the remainder of the biochemical profile was largely unremarkable due to the very low prevalence of cirrhosis among these patients.

Clinical Features and Resistance to Entecavir Monotherapy of Patients with Hepatitis B

AIM

Hepatitis B virus (HBV) infection is a major public health concern worldwide. Entecavir (ETV), a first-line nucleos(t)ide analogue (NA) for HBV, has a low risk of resistance. We evaluated the efficacy of ETV monotherapy, ratio of ETV-resistant, and the clinical features of patients with ETV resistance.

METHODS

A total of 130 patients (72 males, 58 females; mean age, 61 ± 15 years) were divided into a NA-naïve group (n = 108) and NA-experienced group (n = 22). We examined the clinical outcomes of ETV monotherapy and associated factors. We also assessed the clinical features of 15 patients with resistance to ETV (mean, 51.0 ± 27.4 weeks).

RESULTS

Among the 130 patients, 94.1% achieved ALT normalization and 63.6% achieved serum HBV DNA negativity after ETV monotherapy for 96 weeks. Of the patients in the NA-naïve group, 93.1% and 60.4% achieved ALT normalization and HBV DNA negativity, respectively. Of the patients in the NA-experienced group, 100% and 74.9% achieved ALT normalization and HBV DNA negativity, respectively. Compared to patients on ETV continuously, 15 ETV-resistant patients had a higher baseline HBV viral load. There was a significant difference in the time to HBV DNA negativity, but not ALT normalization after ETV monotherapy in these groups. Rescue treatment with other NAs led to ALT normalization in all of these patients, but not HBV DNA negativity.

CONCLUSIONS

ETV monotherapy has a long-term clinical efficacy. While some patients especially with HBV DNA high viral load developed ETV resistance, rescue treatment led to ALT normalization in these patients.

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 (P_trend = 0.004), while the eGFR trend (P_trend  > 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.

Antiviral Drug Delivery System for Enhanced Bioactivity, Better Metabolism and Pharmacokinetic Characteristics

Antiviral drugs (AvDs) are the primary resource in the global battle against viruses, including the recent fight against corona virus disease 2019 (COVID-19). Most AvDs require multiple medications, and their use frequently leads to drug resistance, since they have poor oral bioavailability and low efficacy due to their low solubility/low permeability. Characterizing the in vivo metabolism and pharmacokinetic characteristics of AvDs may help to solve the problems associated with AvDs and enhance their efficacy. In this review of AvDs, we systematically investigated their structure-based metabolic reactions and related enzymes, their cellular pharmacology, and the effects of metabolism on AvD pharmacodynamics and pharmacokinetics. We further assessed how delivery systems achieve better metabolism and pharmacology of AvDs. This review suggests that suitable nanosystems may help to achieve better pharmacological activity and pharmacokinetic behavior of AvDs by altering drug metabolism through the utilization of advanced nanotechnology and appropriate administration routes. Notably, such AvDs as ribavirin, remdesivir, favipiravir, chloroquine, lopinavir and ritonavir have been confirmed to bind to the severe acute respiratory syndrome-like coronavirus (SARS-CoV-2) receptor and thus may represent anti-COVID-19 treatments. Elucidating the metabolic and pharmacokinetic characteristics of AvDs may help pharmacologists to identify new formulations with high bioavailability and efficacy and help physicians to better treat virus-related diseases, including COVID-19.

Management of Hepatitis B Virus Reactivation in Malignant Lymphoma Prior to Immunosuppressive Treatment

Hepatitis B reactivation is a common complication in lymphoma patients under immunosuppressive treatment with potentially serious and life-threating consequences. In this review, we discuss the basis of chronic Hepatitis B virus (HBV) infection, the definition and risk factors for HBV reactivation. We overview the management of HBV reactivation based on virological status and immunosuppressive regimen risk stratification. We also highlight and update information about the HBV reactivation in lymphoma patients under novel agent treatment, including newer monoclonal antibodies, small molecule inhibitors, and even chimeric antigen receptor T-cell immunotherapy.

Life-long passion for antiviral research and drug development: 80th birthday of Prof. Dr. Erik De Clercq

Since the 1950s, great efforts have been made to develop antiviral agents against many infectious diseases such as human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), human cytomegalovirus (HCMV), herpes simplex virus (HSV), and varicella-zoster virus (VZV). Among the list of nearly 106 antiviral agents approved in the past five decades, Prof. Erik De Clercq has contributed to the development of 7 antiviral drugs: tenofovir disoproxil fumarate (Viread®) for HIV and HBV treatment, tenofovir alafenamide (Vemlidy®) for HIV and HBV treatment, brivudine (Zostex®) for HSV-1 and VZV treatment, valacyclovir (Valtrex®) for HSV and VZV treatment, adefovir dipivoxil (Hepsera®) for HBV treatment, stavudine (Zerit®) for HIV treatment, and cidofovir (Vistide®) for treating HCMV retinitis in AIDS patients. In addition to the above antiviral drugs, his contributions include two anti-cancer drugs: rabacfosadine (Tanovea®-CA1) for canine lymphoma and plerixafor (Mozobil®) for multiple myeloma and non-Hodgkin's lymphoma. These achievements are driven by his life-long passions for antiviral research and successful collaborations worldwide. To honor the 80th birthday of Prof. Erik De Clercq, this study highlights his scientific achievements and the importance of life-long passions and collaborations in the success of antiviral research and drug development.

Tenofovir-disoproxil-fumarate modulates lipid metabolism via hepatic CD36/PPAR-alpha activation in hepatitis B virus infection

BACKGROUND

Entecavir and tenofovir-disoproxil-fumarate are first-line nucleos(t)ide analogs (NA) for treatment of hepatitis B virus (HBV) infections; however, their long-term administration can impact extrahepatic organs. Herein, we sought to examine the effect of NA on lipid metabolism while also characterizing the associated mechanism.

METHODS

A retrospective study was performed on HBV patients administered entecavir or tenofovir-disoproxil-fumarate. Patient clinical information, as well as their preserved serum samples obtained at baseline and 6-12 months after treatment initiation, were analyzed. A 1:1 propensity score matching was applied to the assignment of tenofovir-disoproxil-fumarate or entecavir treatment. Changes in serum cholesterol, including oxidized-LDL, were analyzed. Subsequently, in vitro analysis elucidated the mechanism associated with the effect of NAs on lipid metabolism.

RESULTS

Administration of tenofovir-disoproxil-fumarate, not entecavir, to chronic HBV patients, decreased serum cholesterol levels, including non-HDL and oxidized-LDL, which are strongly associated with arteriosclerosis. In vitro analysis revealed that tenofovir-disoproxil-fumarate reduced supernatant cholesterol, and upregulated the scavenger receptor, CD36, in hepatocytes. Meanwhile, silencing of hepatic CD36 increased supernatant cholesterol and negated the cholesterol-reducing effect of tenofovir-disoproxil-fumarate in HepG2-cells. Reporter, microarray, and RT-PCR analyses further revealed that tenofovir-disoproxil-fumarate treatment activates PPAR-α-mediated signaling, and upregulates PPAR-α target genes, including CPT1 and CD36. Alternatively, silencing of PPAR-α reversed the effects of tenofovir-disoproxil-fumarate on CD36.

CONCLUSIONS

Tenofovir-disoproxil-fumarate modulates lipid metabolism by upregulating hepatic CD36 via PPAR-α activation. Since dyslipidemia could be associated with arteriosclerosis and hepatocarcinogenesis, these discoveries provide novel insights into anti-HBV therapies, as well as the associated extrahepatic effects of NA.

Broad spectrum antiviral nucleosides-Our best hope for the future

The current focus for many researchers has turned to the development of therapeutics that have the potential for serving as broad-spectrum inhibitors that can target numerous viruses, both within a particular family, as well as to span across multiple viral families. This will allow us to build an arsenal of therapeutics that could be used for the next outbreak. In that regard, nucleosides have served as the cornerstone for antiviral therapy for many decades. As detailed herein, many nucleosides have been shown to inhibit multiple viruses due to the conserved nature of many viral enzyme binding sites. Thus, it is somewhat surprising that up until very recently, many researchers focused more on "one bug one drug," rather than trying to target multiple viruses given those similarities. This attitude is now changing due to the realization that we need to be proactive rather than reactive when it comes to combating emerging and reemerging infectious diseases. A brief summary of prominent nucleoside analogues that previously exhibited broad-spectrum activity and are now under renewed interest, as well as new analogues, that are currently under investigation against SARS-CoV-2 and other viruses is discussed herein.

Advanced Therapeutics, Vaccinations, and Precision Medicine in the Treatment and Management of Chronic Hepatitis B Viral Infections; Where Are We and Where Are We Going?

The management of chronic hepatitis B virus (CHB) infection is an area of massive unmet clinical need worldwide. In spite of the development of powerful nucleoside/nucleotide analogue (NUC) drugs, and the widespread use of immune stimulators such as interferon-alpha (IFNα) or PEGylated interferon-alpha (PEG-IFNα), substantial improvements in CHB standards of care are still required. We believe that the future for CHB treatment now rests with advanced therapeutics, vaccination, and precision medicine, if all are to bring under control this most resilient of virus infections. In spite of a plethora of active drug treatments, anti-viral vaccinations and diagnostic techniques, the management of CHB infection remains unresolved. The reason for this is the very complexity of the virus replication cycle itself, giving rise to multiple potential targets for therapeutic intervention some of which remain very intractable indeed. Our review is focused on discussing the potential impact that advanced therapeutics, vaccinations and precision medicine could have on the future management of CHB infection. We demonstrate that advanced therapeutic approaches for the treatment of CHB, in the form of gene and immune therapies, together with modern vaccination strategies, are now emerging rapidly to tackle the limitations of current therapeutic approaches to CHB treatment in clinic. In addition, precision medicine approaches are now gathering pace too, starting with personalized medicine. On the basis of this, we argue that the time has now come to accelerate the design and creation of precision therapeutic approaches (PTAs) for CHB treatment that are based on advanced diagnostic tools and nanomedicine, and which could maximize CHB disease detection, treatment, and monitoring in ways that could genuinely eliminate CHB infection altogether.