HIV Prevention Among Men Who Have Sex With Men: Tenofovir Alafenamide Combination Preexposure Prophylaxis Versus Placebo.

BACKGROUND: While noninferiority of tenofovir alafenamide and emtricitabine (TAF/FTC) as preexposure prophylaxis (PrEP) for the prevention of human immunodeficiency virus (HIV) has been shown, interest remains in its efficacy relative to placebo. We estimate the efficacy of TAF/FTC PrEP versus placebo for the prevention of HIV infection. METHODS: We used data from the DISCOVER and iPrEx trials to compare TAF/FTC to placebo. DISCOVER was a noninferiority trial conducted from 2016 to 2017. iPrEx was a placebo-controlled trial conducted from 2007 to 2009. Inverse probability weights were used to standardize the iPrEx participants to the distribution of demographics and risk factors in the DISCOVER trial. To check the comparison, we evaluated whether risk of HIV infection in the shared tenofovir disoproxil fumarate and emtricitabine (TDF/FTC) arms was similar. RESULTS: Notable differences in demographics and risk factors occurred between trials. After standardization, the difference in risk of HIV infection between the TDF/FTC arms was near zero. The risk of HIV with TAF/FTC was 5.8 percentage points lower (95% confidence interval [CI], -2.0% to -9.6%) or 12.5-fold lower (95% CI, .02 to .31) than placebo standardized to the DISCOVER population. CONCLUSIONS: There was a reduction in HIV infection with TAF/FTC versus placebo across 96 weeks of follow-up. CLINICAL TRIALS REGISTRATION: NCT02842086 and NCT00458393.

A Phase 1 Clinical Trial to Assess the Safety and Pharmacokinetics of a Tenofovir Alafenamide/Elvitegravir Insert Administered Rectally for HIV Prevention.

BACKGROUND: On-demand topical products could be an important tool for human immunodeficiency virus (HIV) prevention. We evaluated the safety, pharmacokinetics, and ex vivo pharmacodynamics of a tenofovir alafenamide/elvitegravir (TAF/EVG, 20 mg/16 mg) insert administered rectally. METHODS: MTN-039 was a phase 1, open-label, single-arm, 2-dose study. Blood, rectal fluid, and rectal tissue were collected over 72 hours following rectal administration of 1 and 2 TAF/EVG inserts for each participant. RESULTS: TAF/EVG inserts were safe and well tolerated. EVG and tenofovir (TFV) were detected in blood plasma at low concentrations: median peak concentrations after 2 inserts were EVG 2.4 ng/mL and TFV 4.4 ng/mL. Rectal tissue EVG peaked at 2 hours (median, 2 inserts = 9 ng/mg) but declined to below limit of quantification in the majority of samples at 24 hours, whereas tenofovir diphosphate (TFV-DP) remained high >2000 fmol/million cells for 72 hours with 2 inserts. Compared to baseline, median cumulative log10 HIV p24 antigen of ex vivo rectal tissue HIV infection was reduced at each time point for both 1 and 2 inserts (P < .065 and P < .039, respectively). DISCUSSION: Rectal administration of TAF/EVG inserts achieved high rectal tissue concentrations of EVG and TFV-DP with low systemic drug exposure and demonstrable ex vivo inhibition of HIV infection for 72 hours. Clinical Trials Registration . NCT04047420.

Female genital tract host factors and tenofovir and lamivudine active metabolites.

BACKGROUND: We previously reported the effect of contraception on cervical tenofovir concentrations in Ugandan women living with HIV. Here we explored the role of cervicovaginal cytokines and drug metabolizing enzymes and transporters (DMETs) to elucidate FGT drug disposition in a Ugandan cohort. METHODS: Cervicovaginal fluid and cervical biopsies were collected from Ugandan women living with HIV receiving tenofovir/lamivudine-based therapy and intramuscular depot medroxyprogesterone acetate (DMPA-IM; n=25), copper IUD (cuIUD; n=12), or condoms (n=13) as contraception. Cytokines were measured in cervicovaginal fluid (CVF). Ectocervical tenofovir diphosphate (TFVdp) and lamivudine triphosphate (3TCtp), dATP/dCTP concentrations, and immune marker/DMETs gene expression were measured in cervical biopsies. RESULTS: Cervical 3TCtp was not correlated with any CVF cytokines. Cervical TFVdp was correlated with IL-10, IL-7, and IL-17 in CVF. CCR5 mRNA expression in cervical biopsies was higher in cuIUD-users versus condoms-users. Using multivariable linear regression, CVF IL-17, tissue dATP, plasma estradiol, and plasma tenofovir were all significant predictors of cervical TFVdp. Tissue dCTP and plasma lamivudine were significant predictors of cervical 3TCtp. CONCLUSIONS: TFVdp concentrations in cervix appear to be influenced by local inflammation. In contrast, 3TCtp FGT exposure was not affected by genital inflammation or DMETS. CuIUD users have more immune cells present, which may in turn influence local TFVdp disposition.

Extended Postexposure Protection Against Vaginal Simian/Human Immunodeficiency Virus Infection With Tenofovir Alafenamide Fumarate/Elvitegravir Inserts in Macaques.

Vaginal inserts that can be used on demand before or after sex may be a desirable human immunodeficiency virus (HIV) prevention option for women. We recently showed that inserts containing tenofovir alafenamide fumarate (TAF, 20 mg) and elvitegravir (EVG, 16 mg) were highly protective against repeated simian/human immunodeficiency virus (SHIV) vaginal exposures when administered to macaques 4 hours before or after virus exposure (93% and 100%, respectively). Here, we show in the same macaque model that insert application 8 hours or 24 hours after exposure maintains high efficacy (94.4% and 77.2%, respectively). These data extend the protective window by TAF/EVG inserts and inform their clinical development for on-demand prophylaxis in women.

Circulating HBV RNA and hepatitis B core-related antigen trajectories in persons with HIV/HBV coinfection and HBsAg loss on tenofovir therapy.

BACKGROUND: We evaluated long-term trajectories of circulating hepatitis B virus (HBV)-RNA and hepatitis B core-related antigen (HBcrAg) in persons with and without hepatitis B surface antigen (HBsAg) loss during tenofovir therapy in the Swiss HIV Cohort Study. METHODS: We included 29 persons with HIV (PWH) with HBsAg loss and 29 matched PWH without loss. We compared HBV-RNA and HBcrAg decline and assessed the cumulative proportions with undetectable HBV-RNA and HBcrAg levels during tenofovir therapy using Kaplan-Meier estimates. RESULTS: HBsAg loss occurred after a median of 4 years (IQR 1 - 8). All participants with HBsAg loss achieved suppressed HBV-DNA and undetectable HBV-RNA preceding undetectable qHBsAg levels, whereas 79% achieved negative HBcrAg. In comparison, 79% of the participants without HBsAg loss achieved undetectable HBV-RNA and 48% negative HBcrAg. After two years on tenofovir, an HBV RNA decline ≥1 log10 copies/ml had 100% sensitivity and 36.4% specificity for HBsAg loss, whereas an HBcrAg decline ≥1 log10 U/ml had 91.0% sensitivity and 64.5% specificity. CONCLUSIONS: HBV-RNA suppression preceded undetectable qHBsAg levels, and had high sensitivity but low specificity for HBsAg loss during tenofovir therapy in PWH. HBcrAg remained detectable in approximately 20% of persons with, and 50% of persons without HBsAg loss.

Weight, anthropometric and metabolic changes after discontinuing antiretroviral therapy containing tenofovir alafenamide (TAF) in people with HIV.

BACKGROUND: Antiretroviral therapy (ART)-related weight gain is of particular concern in people with HIV (PWH). While weight gain was observed among PWH receiving tenofovir alafenamide (TAF), little is known about the potential reversibility after TAF discontinuation. We evaluated weight and metabolic changes 12 months after TAF discontinuation in the Swiss HIV Cohort Study. METHODS: We included participants who received at least six months of TAF-containing ART between January 2016 and March 2023. Using multivariable mixed-effect models, changes in weight and lipid levels were compared between individuals who continued TAF and those who switched to one of the following TAF-free regimens: TDF-based ART, dolutegravir/lamivudine (DTG/3TC), or long-acting cabotegravir/rilpivirine (CAB/RPV). RESULTS: Of 6555 participants (median age 54 years, 24.3% female, 13% Black), 5485 (83.7%) continued and 1070 (16.3%) stopped TAF. Overall, discontinuing TAF was associated with an adjusted mean weight change of -0.54 kg (95% CI -0.98 to -0.11) after 12 months. In stratified analyses, switching from TAF to TDF led to an adjusted mean weight decrease of -1.84 kg (CI -2.72 to -0.97), and to a decrease in mean total cholesterol (-0.44 mmol/L) and triglycerides (-0.38 mmol/L) after 12 months. Switching from TAF-based ART to DTG/3TC (-0.17 kg, CI -0.82 to 0.48) or long-acting CAB/RPV (-0.64 kg, CI -2.16 to 0.89) did not lead to reductions in weight. CONCLUSIONS: Replacing TAF with TDF in PWH led to a decrease in body weight and an improved lipid profile within one year. Weight changes were not observed among individuals who switched to DTG/3TC or long-acting CAB/RPV.

Lipid and glucose profiles in pregnant women with HIV on tenofovir-based antiretroviral therapy.

OBJECTIVE: Tenofovir alafenamide (TAF)-based antiretroviral therapy (ART) regimens have been associated with adverse changes in lipid and glucose profiles compared with tenofovir disoproxil fumarate (TDF)-based ART, but data in pregnancy is limited. We evaluated metabolic markers in pregnant women with HIV after starting TAF- vs TDF-based ART. METHODS: We analyzed data within the IMPAACT 2010/VESTED trial, which demonstrated better pregnancy outcomes in pregnant women randomized to initiate TAF/Emtricitabine/Dolutegravir (TAF/FTC+DTG; n=217) or TDF/FTC+DTG (n=215). We measured non-fasting plasma concentrations of glucose, total-cholesterol, low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), lipoprotein (a), and triglycerides from samples collected eight weeks after enrollment. We employed linear regression models to estimate by-arm mean differences. RESULTS: 219 participants enrolled in the DTG arms in Zimbabwe and Uganda: 109 in the TAF/FTC+DTG and 110 in the TDF/FTC+DTG arms. At study entry, mean gestational age was 22.6 weeks, median HIV-1 RNA was 711 copies/mL, and mean age was 25.8 years. By eight weeks, mean total cholesterol was 12 mg/dL higher in women randomized to TAF/FTC+DTG versus TDF/FTC+DTG (95% CI 3.8, 21.1). Pregnant women in the TAF/FTC+DTG arm had higher mean LDL-C (7.1 mg/dL, 95% CI 0.2, 14.0), triglycerides (12.3 mg/dL, 95% CI 1.8, 22.7), lipoprotein (a) (7.3 mg/dL, 95% CI 1.1, 13.6), and lower mean HDL-C (2.8 mg/dL, 95% CI 0.1, 5.6) compared to the TDF/FTC+DTG arm. CONCLUSION: Pregnant women randomized to start TAF/FTC+DTG had higher lipids than those randomized to TDF/FTC+DTG within eight weeks of ART initiation. However, lipid levels were within normal reference ranges.

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.

Tenofovir-Diphosphate and Emtricitabine-Triphosphate Adherence Benchmarks in Dried Blood Spots for Persons with HIV Receiving Tenofovir Alafenamide and Emtricitabine-based Antiretroviral Therapy (QUANTI-TAF).

BACKGROUND: QUANTI-TAF aimed to establish tenofovir-diphosphate/emtricitabine-triphosphate (TFV-DP/FTC-TP) adherence benchmarks in dried blood spots (DBS) for persons with HIV (PWH) receiving tenofovir alafenamide/emtricitabine (TAF/FTC)-based antiretroviral therapy (ART). METHODS: During a 16-week pharmacokinetic study, PWH received TAF/FTC-based ART co-encapsulated with an ingestible sensor to directly measure cumulative (enrollment to final visit) and 10-day adherence. At monthly visits, intraerythrocytic concentrations of TAF/FTC anabolites (TFV-DP/FTC-TP) in DBS were quantified by LC-MS/MS and summarized at steady-state (week 12 or 16) as median (IQR). Linear mixed-effects models evaluated factors associated with TFV-DP/FTC-TP. RESULTS: 84 participants (86% male, 11% female, and 4% transgender), predominantly receiving bictegravir/TAF/FTC (73%) enrolled. 92% completed week 12 or 16 (94% receiving unboosted ART). TFV-DP for <85% (7/72), ≥85%-<95% (9/72), and ≥95% (56/72) cumulative adherence was 2696 (2039-4108), 3117 (2332-3339), and 3344 (2605-4293) fmol/punches. All participants with ≥85% cumulative adherence had TFV-DP ≥1800 fmol/punches. Adjusting for cumulative adherence, TFV-DP was higher with boosted ART, lower BMI, and in non-Blacks. FTC-TP for <85% (14/77), ≥85%-<95% (6/77), and ≥95% (57/77) 10-day adherence was 3.52 (2.64-4.48), 4.58 (4.39-5.06), and 4.96 (4.21-6.26) pmol/punches. All participants with ≥85% 10-day adherence had FTC-TP ≥2.5 pmol/punches. Low-level viremia (HIV-1 RNA ≥20-<200 copies/mL) occurred at 60/335 (18%) visits in 33/84 (39%) participants (range: 20-149 copies/mL), with similar TFV-DP (3177 [2494-4149] fmol/punches) compared with HIV-1 RNA <20 copies/mL visits (3279 [2580-4407] fmol/punches). CONCLUSIONS: We propose PK-based TFV-DP (≥1800 fmol/punches)/FTC-TP (≥2.5 pmol/punches) benchmarks in DBS for PWH receiving unboosted TAF/FTC-based ART with ≥85% adherence. In the setting of high adherence, low-level viremia was common.

HIV-1 Incidence, Adherence, and Drug Resistance in Individuals Taking Daily Emtricitabine/Tenofovir Disoproxil Fumarate for HIV-1 Pre-Exposure Prophylaxis: Pooled Analysis From 72 Global Studies.

BACKGROUND: Oral pre-exposure prophylaxis (PrEP) with emtricitabine/tenofovir disoproxil fumarate (F/TDF) has high efficacy against HIV-1 acquisition. Seventy-two prospective studies of daily oral F/TDF PrEP were conducted to evaluate HIV-1 incidence, drug resistance, adherence, and bone and renal safety in diverse settings. METHODS: HIV-1 incidence was calculated from incident HIV-1 diagnoses after PrEP initiation and within 60 days of discontinuation. Tenofovir concentration in dried blood spots (DBS), drug resistance, and bone/renal safety indicators were evaluated in a subset of studies. RESULTS: Among 17,274 participants, there were 101 cases with new HIV-1 diagnosis (0.77 per 100 person-years; 95% CI 0.63-0.94). In 78 cases with resistance data, 18 (23%) had M184I or V, one (1.3%) had K65R, and three (3.8%) had both mutations. In 54 cases with tenofovir concentration data from DBS, 45 (83.3%), 2 (3.7%), 6 (11.1%), and 1 (1.9%) had average adherence of <2, 2-3, 4-6, and ≥7 doses/week, respectively, and the corresponding incidence was 3.9 (95% CI 2.9-5.3), 0.24 (0.060-0.95), 0.27 (0.12-0.60), and 0.054 (0.008-0.38) per 100 person-years. Adherence was low in younger participants, Hispanic/Latinx and Black participants, cisgender women, and transgender women. Bone and renal adverse event incidence rates were 0.69 and 11.8 per 100 person-years, respectively, consistent with previous reports. CONCLUSIONS: Leveraging the largest pooled analysis of global PrEP studies to date, we demonstrate that F/TDF is safe and highly effective, even with less than daily dosing, in diverse clinical settings, geographies, populations, and routes of HIV-1 exposure.

Global HIV Incidence Analysis and Implications for Affordability Using Long-Acting Cabotegravir Versus Continuous and Event-Driven Oral Preexposure Prophylaxis.

BACKGROUND: The HIV Prevention Trials Network (HPTN) 083/084 trials showed up to 88% increased efficacy of long-acting cabotegravir (CAB-LA) versus continuous oral tenofovir disoproxil fumarate/emtricitabine (TDF/FTC). However, CAB-LA's high price limits the number of people who can be treated within fixed prevention budgets. Global human immunodeficiency virus (HIV) prevention budgets are highly limited, with TDF/FTC widely available as a low-cost generic. In randomized clinical trials, event-driven TDF/FTC has shown similar preventive efficacy to continuous TDF/FTC. METHODS: A systematic review of global HIV incidence studies was conducted. Weighted incidence was calculated in each at-risk population. HIV infection rates were evaluated for 5 prevention strategies, with additional HIV testing, education, and service access costs assumed for each ($18 per person per year). Assumed efficacies were 90% (continuous CAB-LA), 60% (continuous TDF/FTC), and 60% (event-driven TDF/FTC). Using weighted incidence and an assumed 100 000 target population, annual HIV infection rates by population were calculated for each prevention strategy. RESULTS: Ninety-eight studies in 5 230 189 individuals were included. Incidence per 100 person-years ranged from 0.03 (blood donors) to 3.82 (people who inject drugs). Using the number needed to treat to benefit for each strategy, a mean incidence of 2.6 per 100 person-years in at-risk populations, and a 100 000 target population, current-price continuous CAB-LA cost $949 487 per HIV infection successfully prevented, followed by target-price CAB-LA ($11 453), continuous TDF/FTC ($4231), and event-driven TDF/FTC ($1923). CONCLUSIONS: High prices of CAB-LA limit numbers treatable within fixed budgets. Low-cost event-driven TDF/FTC consistently prevents the most HIV infections within fixed budgets.

Cumulative Tenofovir Exposure Among Patients With HIV/Hepatitis B Coinfection With Differential Viral Suppression.

This case-control study explored cumulative tenofovir exposure among patients with human immunodeficiency virus/hepatis B virus (HIV/HBV) coinfection with HIV viral suppression. Among patients taking tenofovir disoproxil fumarate, median TFV-DP levels in dried blood spots were ∼3-fold lower among patients with incomplete HBV viral suppression (n = 4) compared to those with complete suppression (n = 5) (516 vs 1456 fmol/punch).

Functional cure of hepatitis B in patients with cancer undergoing immune checkpoint inhibitor therapy.

BACKGROUND & AIMS: Immune checkpoint inhibitors (ICIs) can restore exhausted T-cell immunity not only for cancer treatment but also potentially to cure chronic hepatitis B (CHB). Thus, we aimed to determine the previously unclear impact of ICIs on hepatitis B surface antigen (HBsAg) seroclearance in patients with cancer. METHODS: Consecutive patients with cancer from 2016 to 2020 (cohort 1, n = 118), and hepatocellular carcinoma from 2020 to 2022 (cohort 2, n = 44, as validation) receiving ICIs and positive for HBsAg were retrospectively recruited. An additional HBV-HCC cohort (cohort 3, n = 85) not receiving ICIs served as a control group. Factors associated with HBsAg loss or a HBsAg decline >1 log were analyzed. RESULTS: With median follow-up of 17.5 months, 8 (6.8%) patients in cohort 1 and 4 (9.1%) in cohort 2 achieved HBsAg seroclearance, and an additional four in cohort 1 and one in cohort 2 had a HBsAg decline >1 log. In multivariate analysis, HBsAg <100 IU/ml was associated with HBsAg seroclearance (hazard ratio 6.274, p = 0.028). In the validation cohort, the cumulative incidences of HBsAg loss at months 12 and 24 were 13.0% and 38.4%, respectively, for baseline HBsAg <100 IU/ml, which were significantly higher than those in the control group (p = 0.0267). No case in cohort 3 achieved HBsAg loss within 24 months. Of the 17 cases who achieved HBsAg loss or a decline >1 log, 16 (94.1%) received nucleos(t)ide analogue treatment. The median time to HBsAg loss or HBsAg decline was 16.5 (range 9.6 to 27.5) months. CONCLUSIONS: ICIs may accelerate HBsAg seroclearance in patients with cancer and baseline HBsAg <100 IU/ml. This finding provides important information for the design of future trials evaluating the ability of ICIs to induce functional cure in patients with CHB. IMPACT AND IMPLICATIONS: Immune checkpoint inhibitors (ICIs) can restore exhausted T-cell immunity not only for cancer treatment but also potentially to cure chronic hepatitis B. Functional cure of hepatitis B was observed in patients with cancer or HCC undergoing ICI treatment, and the cumulative incidence of HBsAg loss was higher compared with controls without ICIs. ICIs may accelerate the HBsAg loss in patients with baseline HBsAg levels <100 IU/ml. This finding provides important information for the design of future ICI trials evaluating the ability of ICIs to induce functional cure in patients with CHB.

Long-term quantitative hepatitis B surface antigen (HBsAg) trajectories in persons with and without HBsAg loss on tenofovir-containing antiretroviral therapy.

OBJECTIVES: Improving the understanding of the patterns of quantitative hepatitis B surface antigen (qHBsAg) trajectories associated with HBsAg loss is important in light of novel anti-hepatitis B virus agents being developed. We evaluated long-term qHBsAg trajectories in persons with HIV and HBV during tenofovir-containing antiretroviral therapy in the Swiss HIV Cohort Study. METHODS: We included 29 participants with and 29 without HBsAg loss, defined as qHBsAg <0.05 IU/mL. We assessed qHBsAg decline during therapy in both groups and used agglomerative hierarchical clustering to identify different qHBsAg trajectory profiles in persons with HBsAg loss. RESULTS: The median follow-up time was 11.9 years (IQR 8.4-14.1), and the median time to HBsAg loss was 48 months (IQR 12-96). Among participants with HBsAg loss, 79% had a qHBsAg decline ≥1 log10 IU/mL 2 years after starting tenofovir. The trajectories in qHBsAg levels during tenofovir therapy were heterogeneous, characterized by five distinct profiles. Among participants without HBsAg loss, only 7% had a qHBsAg decline ≥1 log10 IU/ml after 2 years. CONCLUSIONS: Most persons with HIV who experienced HBsAg loss had an early decline in qHBsAg levels, with diverse trajectories during long-term tenofovir therapy. In persons without HBsAg loss, qHBsAg levels remained remarkably stable over time.

Role of tenofovir dipivoxil in gut microbiota recovery from HBV-infection induced dysbiosis.

BACKGROUND: Studies have found dysbiosis of the gut microbiota in individuals infected with the hepatitis B virus (HBV). Tenofovir dipivoxil (TDF) is one of the preferred oral antiviral drugs used for the treatment of chronic hepatitis B (CHB), but the extent to which TDF is able to affect the gut microbiota and inflammatory factors of a patient remains largely unexplored. In this study, we collected stool samples from HBV patients prior to medication and from CHB patients treated with TDF. RESULTS: The gut microbiota and inflammatory factors were assessed in 42 healthy subjects (HC group), 109 HBV-infected subjects, including 48 CHB patients who were not medicated with nucleoside analogue drugs (No-NAs group), and 61 CHB patients who were medicated with TDF (TDF group). 16 S rRNA sequencing revealed that TDF treatment caused significant changes in the gut microbiota of HBV-infected individuals; however, the gut microbiota of HBV-infected individuals did not fully recover to a pre-dysbiosis state. The relative abundance of Bacteroidota gradually decreased from the HC group to the No-NAs and TDF groups. The relative abundance of Fusobacteriota was significantly higher in the No-NAs group than in the HC group. At the genus level, Dialister, Eubacterium_hallii_group, Halomonas, Collinsella, Sphingomonas, Xanthomonadaceae_unclassified, and Rhizobiaceae_unclassified were overrepresented; while the abundance of Bacteroides and Fusobacterium decreased significantly in the No-NAs and TDF groups. CONCLUSIONS: This study showed that TDF treatment significantly improved the regulation of the gut microbiota and aided in dysbiosis recovery. We did not observe significant improvement in serum inflammatory factor concentrations, which may be related to the relatively short duration of TDF administration in this study.

Safety of Tenofovir Disoproxil Fumarate Among Breastfeeding Infants of Patients With Chronic Hepatitis B: A Systematic Review.

An integral component to achieving worldwide chronic hepatitis B (CHB) elimination is addressing vertical transmission. Guidelines differ in their recommendations for breastfeeding while on tenofovir disoproxil fumarate (TDF). To conduct a systematic review of published studies analysing the concentration of tenofovir (TFV) in the breast milk of mothers receiving TDF and determining infant exposure from breastfeeding. We conducted a systematic literature search of studies evaluating infant safety from the breast milk of breastfeeding mothers receiving TDF for any indication that reported a TFV breast milk concentration. Daily infant exposure was used to calculate the relative dose of TFV in infants. Other pertinent information collected was the concentration of TFV in maternal and infant plasma, the duration of therapy of TDF and the indication for TDF. We identified 10 studies including 443 patients-266 of whom were mothers, and the remaining were infants-that reported the TFV concentration of breast milk in breastfeeding mothers receiving TDF. A total of 654 breast milk samples were included. The mean TFV concentration from all the studies that reported a median concentration of TFV was 4.8 ng/mL (95% CI [3.8, 5.8]). The mean infant exposure of TFV from breast milk was 0.56 µg/kg/day (95% CI [0.44, 0.68]). The mean relative dose was determined to be 0.01% of the weight-based recommended infant dose. Infant plasma levels of TFV were also collected. This was undetectable in a majority of the studies that reported it. Based on the negligible infant exposure of TFV while breastfeeding, from a pharmacologic and toxicity standpoint, maternal dosing of TDF appears safe for breastfeeding infants.

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.

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.

Comparing a point-of-care urine tenofovir lateral flow assay to self-reported adherence and their associations with viral load suppression among adults on antiretroviral therapy.

BACKGROUND: Point-of-care (POC) lateral flow assays (LFA) to detect tenofovir (TFV) in urine have been developed to measure short-term ART adherence. Limited data exist from people living with HIV in routine care. METHODS: Adults on TFV-containing regimens, having a routine viral load (VL) at an HIV clinic in Cape Town, South Africa were enrolled in a cross-sectional study. Patients recalled missed ART doses in the past three and 7 days and urine was tested using a POC TFV LFA. VL on the day was abstracted from medical records. RESULTS: Among 314 participants, 293 (93%) had VL <1000 copies/mL, 20 (6%) had no TFV detected and 24 (8%) reported ≥1 missed dose in the past 3 days. Agreement between VL ≥1000 and undetectable TFV was higher compared to 3-day recall of ≥1 missed dose (Kappa 0.504 vs. 0.163, p = 0.015). The AUC to detect VL ≥1000 was 0.747 (95% CI 0.637-0.856) for undetectable TFV. This was statistically significantly better than for 7-day recall (0.571 95% CI 0.476-0.666, p = 0.040) but not for 3-day recall (0.587 95% CI 0.492-0.681, p = 0.071) of ≥1 missed dose. CONCLUSION: In this largely virally suppressed cohort, TFV in urine had better agreement with VL than self-reported adherence and was a better predictor of viraemia on two of three self-report measures. Used in combination with VL, the POC urine TFV LFA could flag patients with viraemia in the presence of ART. Further research is needed to understand the potential application in different populations on ART, including pregnant women.

Hepatitis B relapse after entecavir or tenofovir alafenamide cessation under anti-viral prophylaxis for cancer chemotherapy.

BACKGROUND: No study has comparing hepatitis B virus (HBV) relapse rates among patients with both cancer and hepatitis B e antigen (HBeAg)-negative chronic hepatitis B (CHB) who completed anti-viral prophylaxis for chemotherapy and then stopped taking entecavir or tenofovir alafenamide (TAF). METHODS: A total of 227 HBeAg-negative cancer patients without cirrhosis who previously took entecavir (n = 144) or TAF (n = 83) for antiviral prophylaxis were enrolled. RESULTS: The cumulative incidence of virological and clinical relapse at 2 years was 37% and 10.4%, respectively, in the entecavir group, and 46.7% and 19.5%, respectively, in the TAF group. The multivariate analysis revealed that the use of hematologic malignancy, TAF use, and high-viremia group at baseline were independent risk factors for virological relapse, and use of rituximab, TAF use, higher FIB-4 index and high-viremia group at baseline were independent risk factors for clinical relapse. After propensity score-matching, the patients who discontinued TAF therapy still exhibited higher virological (P = 0.031) and clinical relapse rates (P = 0.012) than did those who discontinued entecavir therapy. The patients were allocated to high- (> 2000 IU/mL), moderate- (between 20 and 2000 IU/mL) and low- (< 20 IU/mL) viremia groups. In the high-viremia group, those who had taken TAF for antiviral prophylaxis had higher rates of virological and clinical relapse than did those who had taken entecavir; in the moderate- and low-viremia groups, no significant difference in virological and clinical relapse rates was detected between the entecavir and TAF groups. Three patients experienced hepatic decompensation upon clinical relapse. All three patients were lymphoma and underwent rituximab therapy. One patient developed acute on chronic liver failure and died even though timely retreatment. CONCLUSIONS: In patients with both cancer and CHB who underwent antiviral prophylaxis, TAF use was associated with a higher chance of HBV relapse than entecavir use after nucleos(t)ide analogue cessation, particularly in the high-viremia group. Patients who are hematologic malignancy and undergo a rituximab-containing cytotoxic therapy should be monitored closely after withdrawal from prophylactic NA treatment.