Functional cure induced by tenofovir alafenamide plus peginterferon-alpha-2b in young children with chronic hepatitis B: a case series study.

BACKGROUND AND AIMS: Data on the safety and effectiveness of tenofovir alafenamide (TAF) plus peginterferon-alpha (Peg-IFN-α) in children with chronic hepatitis B (CHB) are lacking. The current study aimed to present the characteristics of four pediatric CHB patients who obtained a functional cure by using TAF and Peg-IFN-α. METHODS: In this case series study initiated in May 2019, ten children who had no clinical symptoms or signs received response-guided (HBV DNA undetectable, hepatitis B e antigen [HBeAg] loss or seroconversion, and hepatitis B surface antigen [HBsAg] loss or seroconversion) and functional cure-targeted (HBsAg loss or seroconversion) TAF (25 mg/d, orally) plus Peg-IFN-α-2b (180 µg/1.73m2, subcutaneously, once weekly) in combination (9/10) or sequential (1/10) therapy. The safety and effectiveness of these treatments were monitored. RESULTS: As of April 2024, four out of ten children obtained a functional cure after a mean of 31.5 months of treatment, and the other six children are still undergoing treatment. These four cured children, aged 2, 4, 8, and 6 years, were all HBeAg-positive and had alanine aminotransferase levels of 80, 47, 114, and 40 U/L; HBV DNA levels of 71200000, 93000000, 8220, and 96700000 IU/mL; and HBsAg levels of 39442.8, 15431.2, 22, and 33013.1 IU/mL, respectively. During treatment, all the children (10/10) experienced mild or moderate adverse events, including flu-like symptoms, anorexia, fatigue, and cytopenia. Notably, growth retardation (8/10) was the most significant adverse event; and it occurred in three cured children (3/4) treated with combination therapy and was present to a low degree in the other cured child (1/4) treated with sequential therapy. Fortunately, all three cured children recovered to or exceeded the normal growth levels at 9 months posttreatment. CONCLUSIONS: TAF plus Peg-IFN-α-2b therapy is potentially safe and effective for pediatric CHB patients, which may provide important insights for future clinical practice and study designs targeting functional cures for children with CHB.

Comparative evaluation of adverse drug reactions for tenofovir alafenamide and tenofovir disoproxil fumarate using the FAERS Database: a disproportionality analysis.

BACKGROUND: Tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) are widely used nucleoside reverse transcriptase inhibitors (NRTIs), necessitating a thorough understanding of their safety profiles to ensure optimal patient care and treatment adherence. METHODS: We employed statistical methods including the reporting odds ratio (ROR), proportional reporting ratio (PRR), Bayesian Confidence Propagation Neural Network (BCPNN), and Multi-Item Gamma Poisson Shrinker (MGPS) to compare and evaluate the safety profiles of these NRTIs. RESULTS: TAF was significantly associated with weight increase (ROR: 6.43; 95% CI: 5.93-6.96) and specific psychiatric disorders. TDF showed a notable signal for renal disorders and product-related issues, including product dose omission (ROR: 3.53; 95% CI: 3.22-3.87). Additionally, the study highlighted differences in safety signals related to pregnancy outcomes, with TAF having a higher ROR for maternal exposure (ROR: 7.83; 95% CI: 7.06-8.69) and TDF for fetal exposure (ROR: 4.51; 95% CI: 3.93-5.18), underscoring the need for cautious use in pregnant women. The comparative analysis also identified signals for osteonecrosis (ROR: 108.81; 95% CI: 106.25-111.43) and bone loss (ROR: 714; 95% CI: 685.49-743.68) for TAF and TDF, respectively, highlighting the importance of bone health considerations in treatment plans. CONCLUSION: These findings underscore the importance of personalized antiviral therapy and patient safety.

Coformulated Bictegravir/Emtricitabine/Tenofovir Alafenamide for Postexposure Prophylaxis After Sexual Assault: A Retrospective Real-World Study.

We report the experience of bictegravir/emtricitabine/tenofovir alafenamide for nonoccupational postexposure prophylaxis in sexual assault cases. Between June 2021 and October 2023, 39 individuals completed the 28-day follow-up; 41% experienced some side effects, and 1 person discontinued the drug because of a rash. No individuals seroconverted to HIV during the follow-up period.

Short-Term Efficacy of Tenofovir Alafenamide in Acute-On-Chronic Liver Failure: A Single Center Experience.

Background: Patients with acute-on-chronic liver failure (ACLF) who take entecavir (ETV) and tenofovir disoproxil fumarate (TDF) experience a reduction in hepatic events and mortality. The effectiveness of tenofovir alafenamide (TAF) was not well investigated. This study was aim to compare the antiviral efficacy and mortality between TAF and ETV in patients with ACLF caused by the hepatitis B virus (HBV). Methods: One hundred and six patients with HBV-ACLF who received TAF (25 mg/day) and ETV (0.5 mg/day) for 12 weeks were analyzed. The primary endpoints were overall mortality and liver transplantation (LT) at week 12. Biochemical responses, virologic responses, mortality, drug safety, and side effects were evaluated. Results: At 4 and 12 weeks of TAF treatment, patients showed significantly higher HBV-DNA reduction (P < .001), higher HBV-DNA undetectability rates (P < .001), and lower HBV DNA levels (P < .001) in serum. Lower Child-Turcotte-Pugh (CTP) scores (P = .003) were observed at 4 weeks in the TAF group, although the CTP scores showed no difference between TAF group and ETV group at 12 weeks (P = 1.143). Lower alanine aminotransferase (ALT) levels of patients in the TAF group at week 4 and 12 were observed (P = .023 and P < .0001, separately). The mortality of TAF group was lower after 4 weeks of treatment (P = .038); however, the 2 groups had similar mortality rates at week 8 and 12. Among the causes of death in HBV-ACLF patients, we found the same incidence of liver-related problems in both groups (P > .05). Conclusions: This study showed that ACLF patients with chronic HBV infection treated with TAF had a rapid decline in HBV DNA, a higher rate of ALT reduction and improved CTP scores compared to the ETV group, thereby improving patient survival.

Factors driving decisions in the use of HIV pre-exposure prophylaxis: a real-world study in the United States.

Background: Uptake of pre-exposure prophylaxis (PrEP) in the United States (US) remains below target, despite reported high efficacy in prevention of HIV infection and being considered as a strategy for ending new HIV transmissions. Here, we sought to investigate drivers for PrEP use and barriers to increased uptake using real-world data. Methods: Data were drawn from the Adelphi PrEP Disease Specific Programme™, a cross-sectional survey of PrEP users and PrEP non-users at risk for HIV and their physicians in the US between August 2021 and March 2022. Physicians reported demographic data, clinical characteristics, and motivations for prescribing PrEP. PrEP users and non-users reported reasons for or against PrEP use, respectively. Bivariate analyses were performed to compare characteris tics of users and non-users. Results: In total, 61 physicians reported data on 480 PrEP users and 121 non-users. Mean ± standard deviation of age of users and non-users was 35.3 ± 10.8 and 32.5 ± 10.8 years, respectively. Majority were male and men who have sex with men. Overall, 90.0% of users were taking PrEP daily and reported fear of contracting HIV (79.0%) and having at-risk behaviors as the main drivers of PrEP usage. About half of non-users (49.0%) were reported by physicians as choosing not to start PrEP due to not wanting long-term medication. PrEP stigma was a concern for both users (50.0%) and non-users (65.0%). More than half felt that remembering to take PrEP (57.0%) and the required level of monitoring (63.0%) were burdensome. Conclusions: Almost half of people at risk for HIV were not taking PrEP due to not wanting long-term daily medication and about half of current PrEP users were not completely adherent. The most common reason for suboptimal adherence was forgetting to take medication. This study highlighted drivers for PrEP uptake from physician, PrEP user, and non-user perspectives as well as the attributes needed in PrEP products to aid increased PrEP uptake.

Improvement of hepatic fibrosis after tenofovir disoproxil fumarate switching to tenofovir alafenamide for three years.

BACKGROUND: Both tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF) are the first-line treatments for chronic hepatitis B (CHB). We have showed switching from TDF to TAF for 96 weeks resulted in further alanine aminotransferase (ALT) improvement, but data remain lacking on the long-term benefits of TDF switching to TAF on hepatic fibrosis. AIM: To assess the benefits of TDF switching to TAF for 3 years on ALT, aspartate aminotransferase (AST), and hepatic fibrosis improvement in patients with CHB. METHODS: A single center retrospective study on 53 patients with CHB who were initially treated with TDF, then switched to TAF to determine dynamic patterns of ALT, AST, AST to platelet ratio index (APRI), fibrosis-4 (FIB-4) scores, and shear wave elastography (SWE) reading improvement at switching week 144, and the associated factors. RESULTS: The mean age was 55 (28-80); 45.3%, males; 15.1%, clinical cirrhosis; mean baseline ALT, 24.8; AST, 25.7 U/L; APRI, 0.37; and FIB-4, 1.66. After 144 weeks TDF switching to TAF, mean ALT and AST were reduced to 19.7 and 21, respectively. From baseline to switching week 144, the rates of ALT and AST < 35 (male)/25 (female) and < 30 (male)/19 (female) were persistently increased; hepatic fibrosis was also improved by APRI < 0.5, from 79.2% to 96.2%; FIB-4 < 1.45, from 52.8% to 58.5%, respectively; mean APRI was reduced to 0.27; FIB-4, to 1.38; and mean SWE reading, from 7.05 to 6.30 kPa after a mean of 109 weeks switching. The renal function was stable and the frequency of patients with glomerular filtration rate > 60 mL/min was increased from 86.5% at baseline to 88.2% at switching week 144. CONCLUSION: Our data confirmed that switching from TDF to TAF for 3 years results in not only persistent ALT/AST improvement, but also hepatic fibrosis improvement by APRI, FIB-4 scores, as well as SWE reading, the important clinical benefits of long-term hepatitis B virus antiviral treatment with TAF.

Tenofovir-Associated Kidney Dysfunction and Bone Fracture: A Case Report and Literature Review.

Tenofovir is an integral part of antiretroviral therapy used to treat HIV. Long-term use of tenofovir has been associated with decreased glomerular filtration rate, leading to chronic kidney disease, as well as acidosis, electrolyte imbalances, and tubular dysfunction. Tenofovir can also disrupt bone health by decreasing renal phosphate absorption, contributing to osteomalacia. This leads to disruption in mineral metabolism, elevated parathyroid hormone levels, and ultimately, low bone mineral density. Replacing tenofovir with alternative antiretroviral therapy can improve kidney function if done early in the course of the disease. Here, we discuss a case of a 65-year-old woman with HIV who presented with advanced renal failure and hypophosphatemia-induced bone fracture attributed to long-term use of tenofovir. We conclude monitoring kidney function and considering alternative antiretroviral therapy is important to prevent and manage these side effects in patients on long-term tenofovir therapy.

Blood pressure increases are associated with weight gain and not antiretroviral regimen or kidney function: a secondary analysis from the ADVANCE trial in South Africa.

INTRODUCTION: Recent evidence has raised questions about whether newer HIV treatment regimens, including dolutegravir (DTG) and tenofovir alafenamide (TAF), are associated with increases in blood pressure (BP). METHODS: We assessed changes in BP by treatment regimen and evaluated the relative contribution of kidney function and weight gain to these changes among participants in the ADVANCE phase-3 trial clinical trial in South Africa (study dates: January 2017-February 2022). Our primary outcome of interest was a change in systolic BP (SBP) at 96 and 192 weeks, among those not receiving antihypertensive medication. The secondary outcome was treatment-emergent hypertension at these same time points, defined as BP ≥140/90 mmHg on two occasions, or initiation of antihypertensive medication after week 4 among individuals without hypertension at enrolment. We used linear regression to evaluate the relationship between change in estimated glomerular filtration rate (eGFR) and change in SBP; and Poisson regression to evaluate the relationship between change in eGFR and treatment-emergent hypertension at each time point. All models were adjusted for age, sex, treatment group and change in body mass index (BMI). RESULTS: Over 96 weeks, the average changes in SBP were 1.7 mmHg (95% CI: 0.0-3.4), -0.5 mmHg (95% CI: -2.2 to 1.7) and -2.1 mmHg (95% CI: -3.8 to 0.4) in the TAF/emtricitabine (FTC)/DTG, tenofovir disoproxil fumarate (TDF)/FTC/DTG and TDF/FTC/efavirenz (EFV) groups, respectively. This difference was significant for the TAF/FTC/DTG compared to the TDF/FTC/EFV group (p = 0.002). Over 96 weeks, 18.2% (95% CI: 13.4-22.9), 15.4% (95% CI: 11.0-19.9) and 13.3% (95% CI: 8.9-17.6) of participants developed treatment-emergent hypertension, respectively. In adjusted models, there was no significant relationship between change in eGFR and either outcome. Change in BMI was significantly associated with an increase in SBP, while age was associated with an increased risk of treatment-emergent hypertension. Adjustment for BMI also mitigated the unadjusted relationship between HIV treatment regimen and SBP where present. CONCLUSIONS: In the ADVANCE cohort, weight gain and age accounted for increases in BP and risk of treatment-emergent hypertension. HIV treatment programmes may need to integrate the management of obesity and hypertension into routine care. CLINICAL TRIAL NUMBER: NCT03122262.

Effect of Two Forms of Tenofovir on Duodenal Enterocytes - a Hypothesis for Different Effect of TDF and TAF on Body Weight and Plasma Lipids.

BACKGROUND: Tenofovir disoproxil fumarate (TDF) compared to tenofovir alafenamide (TAF) leads to lower body weight and plasma lipids by an unknown mechanism. We hypothesize that TDF, when absorbed, may damage enterocytes of the proximal duodenum, leading to reduced absorption of nutrients. METHODS: People living with HIV, without significant gastrointestinal symptoms, receiving TDF (n=12) or TAF (n=12) containing regimen underwent esophagogastroduodenoscopies with duodenal biopsies. Plasma/serum concentrations of nutrients absorbed from proximal duodenum and serum intestinal fatty-acid-binding protein (I-FABP), a marker of enterocyte damage, were measured. COX/SDH histochemical staining and electron microscopy (EM) were conducted to evaluate mitochondria. RESULTS: Five patients in TDF (celiac disease (excluded from further analyses), helicobacter gastritis, and three esophagitis) and two in TAF group (two esophagitis) had a pathological finding in esophagogastroduodenoscopy. Villi were flatter (337 (59) vs. 397 (42) µm, p=0.016), crypts non-significantly deeper (200 (46) vs. 176 (27) µm, p=0.2), and villus to crypt ratio lower (1.5 (0.42) vs. 2.5 (0.51), p=0.009) in TDF vs. TAF group. I-FABP concentration was higher in TDF vs. TAF group (3.0 (1.07) vs. 1.8 (0.53) ng/ml, p=0.003). TDF group had numerically but not statistically significantly lower concentrations of folate, vitamins A, B1, D, and E. COX/SDH staining showed signs of mitochondrial damage in 10 participants in TDF and 11 in TAF group. EM studies showed similar mitochondrial damage in both groups. CONCLUSIONS: Duodenal villous alterations may explain TDF-associated decrease in body weight and plasma lipids. Larger studies are needed to evaluate concentrations of nutrients absorbed from duodenum among TDF users.

Safety and adherence of bictegravir/emtricitabine/tenofovir alafenamide for HIV post-exposure prophylaxis among adults in Guiyang China: a prospective cohort study.

BACKGROUND: The effectiveness of post-exposure prophylaxis (PEP) depends on participants adherence, making it crucial to assess and compare regimen options to enhance human immunodeficiency virus (HIV) prophylaxis strategies. However, no prospective study in China has shown that the completion rate and adherence of single-tablet regimens in HIV PEP are higher than those of multi-tablet preparations. Therefore, this study aimed to assess the completion rate and adherence of two HIV PEP regimens. METHODS: In this single-center, prospective, open-label cohort study, we included 179 participants from May 2022 to March 2023 and analyzed the differences in the 28-day medication completion rate, adherence, safety, tolerance, and effectiveness of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) and tenofovir disoproxil fumarate, emtricitabine, and dolutegravir (TDF/FTC + DTG). RESULTS: The PEP completion rate and adherence were higher in the BIC/FTC/TAF group than in the TDF/FTC + DTG group (completion rate: 97.8% vs. 82.6%, P = 0.009; adherence: 99.6 ± 2.82% vs. 90.2 ± 25.29%, P = 0.003). The incidence of adverse reactions in the BIC/FTC/TAF and TDF/FTC + DTG groups was 15.2% and 10.3% (P = 0.33), respectively. In the TDF/FTC + DTG group, one participant stopped PEP owing to adverse reactions (1.1%). No other participants stopped PEP due to adverse events. CONCLUSIONS: BIC/FTC/TAF and TDF/FTC + DTG have good safety and tolerance as PEP regimens. BIC/FTC/TAF has a higher completion rate and increased adherence, thus, is recommended as a PEP regimen. These findings emphasize the importance of regimen choice in optimizing PEP outcomes. TRIAL REGISTRATION: The study was registered in the Chinese Clinical Trial Registry (registration number: ChiCTR2200059994(2022-05-14), https://www.chictr.org.cn/bin/project/edit?pid=167391 ).

Metabolic effects and cardiovascular disease risks of antiviral treatments in patients with chronic hepatitis B.

Different antiviral treatments for chronic hepatitis B (CHB) have been known to have different metabolic effects. This study aimed to reveal whether tenofovir alafenamide (TAF)-induced dyslipidemia and its associated outcomes are significant. This study utilized 15-year historical cohort including patients with CHB in Korea and consisted of two parts: the single-antiviral and switch-antiviral cohorts. In the single-antiviral cohort, patients were divided into four groups (entecavir [ETV]-only, tenofovir disoproxil fumarate [TDF]-only, TAF-only, and non-antiviral). Propensity score matching (PSM) and linear regression model were sequentially applied to compare metabolic profiles and estimated atherosclerotic cardiovascular disease (ASCVD) risks longitudinally. In the switch-antiviral cohort, pairwise analyses were conducted in patients who switched NAs to TAF or from TAF. In the single-antiviral cohort, body weight and statin use showed significant differences between groups before PSM, but well-balanced after PSM. Changes in total cholesterol were significantly different between groups (-2.57 mg/dL/year in the TDF-only group and +2.88 mg/dL/year in the TAF-only group; p = 0.002 and p = 0.02, respectively). In the TDF-only group, HDL cholesterol decreased as well (-0.55 mg/dL/year; p < 0.001). The TAF-only group had the greatest increase in ASCVD risk, followed by the TDF-only group and the non-antiviral group. In the switch-antiviral cohort, patients who switched from TDF to TAF had a higher total cholesterol after switching (+9.4 mg/dL/year) than before switching (-1.0 mg/dL/year; p = 0.047). Sensitivity analysis on data with an observation period set to a maximum of 3 years for NA treatment showed consistent results on total cholesterol (-2.96 mg/dL/year in the TDF-only group and +3.09 mg/dL/year in the TAF-only group; p = 0.001 and p = 0.005, respectively). Another sensitivity analysis conducted on statin-treated patients revealed no significant change in cholesterol and ASCVD risk. TAF was associated with increased total cholesterol, whereas TDF was associated with decreased total and HDL cholesterol. Both TAF and TDF were associated with increased ASCVD risks, and statin use might mitigate these risks.

Effect of aluminium oxide nanoparticles on long-acting oleogels laden with Sc-PLA-chitosan nanoparticles for anti-HIV therapy.

The development of a long-acting injectable drug delivery systems (DDS) of active pharmaceutical ingredients (API) holds great promise in addressing the challenges of treatment adherence, predominantly in HIV/AIDS. Polymers are inevitable carriers for the preparation of DDS, which are typically composed of polylactide (PLA), carbohydrates such as chitosan or cellulose derivatives. In this study, the tenofovir alafenamide (TAF) laden PLA-stereocomplex-chitosan nanoparticles (Sc-PLA-chitosan NPs) were developed through the spray-dried technique. These NPs had a mean particle size of 91 ± 8 nm and were incorporated into oleogels consisting of sesame oil and ethyl-cellulose. To enhance the syringeability of highly viscous oleogels, the commercially available aluminium oxide NPs were added with a size of 78 nm. The proposed DDS exhibits prolonged sustained release for up to 12 days in phosphate buffer pH 7.4. Noteworthy, the oleogels with Sc-PLA-chitosan NPs displayed extended tissue permeation properties indicating their potential long-acting in-vivo drug release. Collectively, this study recommends that the development of Sc-PLA-chitosan NPs-loaded oleogels represents a certainly adaptable long-acting injectables system for the delivery of APIs in the context of HIV/AIDS. This system is expected to contribute to improved and effective treatment adherence among patients infected with HIV and provide requisite therapeutic outcomes.

Systemic delivery of bictegravir and tenofovir alafenamide using dissolving microneedles for HIV preexposure prophylaxis.

Human immunodeficiency virus (HIV) continues to pose a serious threat to global health. Oral preexposure prophylaxis (PrEP), considered highly effective for HIV prevention, is the utilisation of antiretroviral (ARV) drugs before HIV exposure in high-risk uninfected individuals. However, ARV drugs are associated with poor patient compliance and pill fatigue due to their daily oral dosing. Therefore, an alternative strategy for drug delivery is required. In this work, two dissolving microneedle patches (MNs) containing either bictegravir (BIC) or tenofovir alafenamide (TAF) solid drug nanoparticles (SDNs) were developed for systemic delivery of a novel ARV regimen for potential HIV prevention. According to ex vivo skin deposition studies, approximately 11% and 50% of BIC and TAF was delivered using dissolving MNs, respectively. Pharmacokinetic studies in Sprague Dawley rats demonstrated that BIC MNs achieved a long-acting release profile, maintaining the relative plasma concentration above the 95% inhibitory concentration (IC95) for 3 weeks. For TAF MNs, a rapid release of drug and metabolism of TAF into TFV were obtained from the plasma samples. This work has shown that the proposed transdermal drug delivery platform could be potentially used as an alternative method to systemically deliver ARV drugs for HIV PrEP.

Lipid safety of tenofovir alafenamide during 96-week treatment in treatment-naive chronic hepatitis B patients.

Background: This study was aimed at investigating the dynamics of lipids and the effect of TAF on the lipid profile of patients including fatty liver disease in CHB patients. Methods: The data of TC, LDL-c, HDL-c, TG, and TC/HDL ratio were collected at baseline, 24 weeks, 48 weeks, 72 weeks, and 96 weeks. CHB patients with fatty liver at baseline were further analyzed in a subgroup. Results: A total of 137 CHB patients treated with TAF were enrolled in this study. During 96 weeks of TAF treatment, there was no significant change in TC, LDL-c, HDL-c, and TG level (P > 0.05). The TC/HDL-c ratio was increased with no significant change (+0.24, P > 0.05). In CHB patients with fatty liver (n = 48), TC, LDL-c, and TC/HDL-c ratio increased gradually during TAF treatment, TG levels increased to 146.63 mg/dL at 48 weeks (P = 0.057) and then decreased, but there was still no significant change compared with the baseline level by 96 weeks (P > 0.05). Conclusion: TAF treatment had a low effect on the lipid profile of CHB patients over the course of 96 weeks, and it was safe even in patients with fatty liver. Clinical trial registration: [https://www.chictr.org.cn/showproj.html?proj=65123], identifier [ChiCTR2000041005].

Evaluation of genotoxic and mitotoxic effects of TAF-loaded chitosan nanoparticles in HepG2 cells.

Tenofovir alafenamide (TAF) is a new drug from the nucleotide reverse transcriptase inhibitor group approved for the treatment of chronic Hepatitis B in 2016. With this study, we aimed to test whether possible cellular toxicity can be reduced by controlled drug release as a result of loading with chitosan nanoparticles (CHS). We investigated the genotoxic and mitotoxic effects of 45 µM TAF-loaded CHS and TAF-only on HepG2 cells by micronucleus (MN), comet assay, determination of mtDNA quantification, mitochondrial membrane potential (ΔΨm), and ROS levels. Additionally, we compared the samples by RNAseq analyses to reveal the transcriptional responses to each regimen. In terms of genotoxic tests, although MN and comet were found higher in all experimental treatment conditions, the encapsulation of CHS reduced the genotoxicity of TAF. MtDNA level was found to be lower in the TAF treatment, whereas it was higher in CHS and CHS-TAF treatments. The TAF-loaded CHS and TAF treatments had an impaired ΔΨm value. Cellular ROS levels were higher in all treatment conditions. According to the analyses of gene expression patterns; CHS-only changed the expression of relatively few genes (187 genes), while TAF changed the expression of the 1974 genes and TAF-loaded CHS changed the expression of 734 genes. Considering the gene expression numbers, CHS encapsulation of TAF significantly reduced the number of genes that were differentially expressed by TAF-only. Overall, we observed that TAF has genotoxic and mitotoxic effects on HepG2 cells, and upon encapsulation with CHS, its genotoxic and mitotoxic effects were decreased.

Evaluation of Pharmacokinetics of a BCS Class III Drug with Two Different Study Designs: Tenofovir Alafenamide Monofumarate Film-coated Tablet.

Tenofovir alafenamide (TAF) is a BCS Class III compound and an oral pro-drug of Tenofovir (TFV) with limited oral bioavailability. The bioavailability of the oral intake increases with food as a result of the low stability of the active substance in the stomach. The reference drug is "Vemlidy® 25 mg Film Tablet", which contains 25 mg of TAF in "hemifumarate" form, is under patent protection until 15.08.2032 by Gilead, and so the "monofumarate" form was used in the present study. At first, a pilot study was conducted involving 12 subjects under fed conditions. The results of the pilot study revealed the test and reference products were not bioequivalent, as a result of insufficient statistical power and high inter-subject variability. Secondly, a physiologically based pharmacokinetic (PBPK) simulation was performed based on the pilot study results and literature data. Finally, the power of the design was increased and the pivotal study design was optimized into a four-period, full-replicated, cross-over study with 34 subjects under fed conditions and it was concluded that the test and reference products were bioequivalent. In conclusion, the present study proved the importance of a correct study design with higher statistical power for a BCS Class III compound with high variability, to present the pharmacokinetics.

Five-year Treatment with Tenofovir Alafenamide Achieves High Rates of Viral Suppression, Alanine Aminotransferase Normalization, and Favorable Bone and Renal Safety in Chinese Chronic Hepatitis B Patients.

Background and Aims: After 3-years (144 week) of double-blind treatment in Chinese chronic hepatitis B patients in two ongoing phase 3 studies, tenofovir alafenamide (TAF) showed similar efficacy to tenofovir disoproxil fumarate (TDF), with improved renal and bone safety. In this study, we aimed to report the 5-year results from 2 years into the open-label TAF treatment phase. Methods: All participants completing the 144-week double-blind treatment were eligible to receive open-label TAF 25 mg once daily up to week 384. Serial analysis of viral suppression (hepatitis B virus DNA <29 IU/mL), alanine aminotransferase normalization, serological responses, and safety outcomes at year 5 (week 240) was performed. Results: The open-label phase included 93% (311/334) of the enrolled participants, which included 212 who switched from double-blind TAF to open-label TAF (TAF-TAF) and 99 who switched from double-blind TDF to open-label TAF (TDF-TAF). Baseline characteristics were comparable. Week 240 viral suppression rates were similar between groups [93.4% vs. 93.9%; difference: -1.5%, (95% CI: -6.4 to -3.5), p=0.857]. Alanine aminotransferase normalization and serological response rates were higher in the TAF-TAF group than in the TDF-TAF group. The frequencies of adverse events and laboratory abnormalities were low and similar between groups. Both groups had similar small numerical declines from baseline in estimated glomerular filtration rate at year 5 (week 240, -2.85 mL/min vs. -3.29 mL/min, p=0.910). The greater declines in renal and bone parameters in the TDF-TAF group through week 144 improved after switching to TAF. Conclusions: The 5-year TAF treatment efficacy was high and similar to that of 3-year TDF followed by 2-year TAF in Chinese chronic hepatitis B patients. Favorable effects on bone and renal parameters were sustained with TAF treatment alone and were observed following the switch from TDF to TAF.

Switching from tenofovir disoproxil fumarate to tenofovir alafenamide in virologically suppressed patient with chronic hepatitis B.

BACKGROUND AND AIM: Our study evaluated the outcomes of switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF) in patients with chronic hepatitis B (CHB). We assessed viral and biochemical responses as well as changes in the estimated glomerular filtration rate (eGFR) and bone mineral density (BMD). METHODS: This retrospective multicenter study included CHB patients who achieved virologic response (VR) (HBV DNA < 20 IU/mL) while on TDF and were subsequently switched to TAF between April 2018 and October 2021. RESULTS: This study included 309 patients with a median age of 59 years, and 42.1% were male. The mean duration of TDF and TAF administration were 54.0 and 37.5 months, respectively. All patients maintained VR after switching to TAF. Alanine aminotransferase (ALT) normalization rate significantly increased 6 months after switching (74.8%-83.5%; P = 0.008). Adjusted eGFR significantly improved at 6 months (+5.55 ± 10.52 mL/min/1.73 m2; P < 0.001) and 12 months (+6.02 ± 10.70 mL/min/1.73 m2; P < 0.001) after switching. In the subgroup of patients with renal impairment (eGFR < 60 mL/min/1.73 m2), significant improvement in renal function was observed at 6 months (+0.6 ± 10.5 mL/min/1.73 m2; P < 0.001) and 12 months (+1.0 ± 10.7 mL/min/1.73 m2; P < 0.001) after switching to TAF. In patients with osteoporosis (n = 182), switching to TAF resulted in significant improvement in spine and hip BMD at 12 months, with increases of 9.7% (95% CI: 7.0-12.5) and 9.4% (95% CI: 7.0-11.8), respectively. CONCLUSION: In this real-world study, switching to TAF was effective and safe in patients, with notable improvements in ALT levels, renal function, and BMD.

Contemporary Treatment Approaches for Human Immunodeficiency Virus Infection: Association of Antiretrovirals with Weight Gain and Potential Solutions.

Integrase inhibitors and tenofovir alafenamide have become a mainstay in modern antiretroviral therapy; more recently, they have been implicated as causing increased weight gain beyond what may be expected with the "return to health" phenomenon. Some patients, namely those assigned female at birth, of the black race, or with lower baseline CD4 counts, may be more likely to experience weight gain. This review outlines existing evidence linking the agents to excessive weight as well as ongoing efforts to combat these effects.

Kinetics of the hepatitis B core-related antigen and treatment responses in chronic hepatitis B patients treated with tenofovir alafenamide.

AIM: An association between hepatitis B core-related antigen (HBcrAg) kinetics and hepatocarcinogenesis during nucleoside (t)id analog (NA) treatment has recently been reported. HBcrAg kinetics and factors associated with HBcrAg response during tenofovir alafenamide (TAF) administration remain unclear. In this multicenter retrospective study, we aimed to clarify the efficacy and safety of TAF in treatment-naïve patients with chronic hepatitis B, focusing on the reduction in HBcrAg levels. METHODS: Patients were treated with TAF monotherapy for 96 weeks, and the kinetics of HBcrAg during treatment and the factors associated with HBcrAg response (defined as a change in HBcrAg of -1 log IU/mL from baseline) were evaluated. RESULTS: The study population comprised 241 patients, 36.9% of whom were HBeAg-positive. The median baseline HBcrAg level was 4.7 log IU/mL. The median change in HBcrAg from baseline was -1.1 log IU/mL at 96 weeks after treatment. The HBcrAg response rate at 96 weeks was 56.6% (43/76). Multivariate analysis revealed high alanine transaminase level as an independent baseline factor associated with HBcrAg response at 96 weeks of treatment (p = 4.53 × 10-6). No correlation was found between the HBcrAg and hepatitis B surface antigen kinetics in patients treated with TAF monotherapy. CONCLUSIONS: In TAF monotherapy for patients with chronic hepatitis B, HBcrAg levels were significantly decreased and baseline alanine transaminase level is an important factor associated with HBcrAg reduction. As no correlation was found between HBcrAg and reduced hepatitis B surface antigen levels in this study, HBcrAg kinetics in addition to hepatitis B surface antigen may need to be monitored during TAF treatment.