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.

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 HIV prevention. We evaluated the safety, pharmacokinetics, and ex vivo pharmacodynamics of a tenofovir alafenamide/elvitegravir (TAF/EVG; 16 mg/20 mg) insert administered rectally.

METHODS

MTN-039 was a Phase 1, open-label, single-arm, 2-dose study. Blood, rectal fluid (RF), and rectal tissue (RT) were collected over 72 hours (hr) following rectal administration of one and two TAF/EVG inserts for each participant. ClinicalTrials.gov Identifier: NCT04047420.

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. RT EVG peaked at 2-hr (median 2 inserts= 9 ng/mg) but declined to BLQ in the majority of samples at 24-hr, whereas TFV-DP remained high >2,000 fmol/million cells for 72-hr with 2 inserts. Compared to baseline, median cumulative log10 HIV p24 antigen of ex vivo rectal tissue HIV infection was reduced at each timepoint for both 1 and 2 inserts (p<0.065 and p<0.039, 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.

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.

Noninferiority Outcomes of Besifovir Compared to Tenofovir Alafenamide in Treatment-Naïve Patients with Chronic Hepatitis B

Background/Aims

: Besifovir dipivoxil maleate (BSV) and tenofovir alafenamide fumarate (TAF) have been recently approved in Korea as the initial antiviral agents for chronic hepatitis B (CHB). However, the real-world outcome data for these drugs remain limited. Therefore, we conducted a noninferiority analysis using real-world data to compare the clinical outcomes of the two nucleotide analogs in treatment-naïve patients with CHB.

Methods

: We retrospectively investigated a cohort of patients with CHB who received BSV or TAF as first-line antiviral agents. The endpoints were virological response (VR) and liver-related clinical outcomes.

Results

: A total of 537 patients, consisting of 202 and 335 patients administered BSV and TAF, respectively, were followed up for 42 months. No significant difference was observed between the VRs of the patients from the two groups. The rates of biochemical response, virologic breakthrough, and incidence rates of hepatocellular carcinoma did not differ between the groups. However, the hepatitis B e antigen seroclearance rate was higher and the renal function declined less in the BSV group. Multivariable analysis indicated older age, alcohol abuse, cirrhosis and ascites, and lower serum HBV DNA level to be independently associated with increased hepatocellular carcinoma risk. The 1:1 propensity score-matched analysis with 400 patients showed VR rates of 85.0% and 88.7% in the BSV and TAF group patients, respectively, at 2 years. The absolute value of the 95% confidence interval for the difference (-0.04 to 0.12) satisfied the a priori limit of a noninferiority of 0.15.

Conclusions

: BSV is noninferior to TAF in terms of VR, and their clinical outcomes are comparable to CHB.

Switching Tenofovir Disoproxil Fumarate (TDF) to Tenofovir Alafenamide Fumarate (TAF) in Hepatitis B/HIV Co-Infection: A Feasibility Study

PURPOSE

Tenofovir alafenamide (TAF) delivers the active metabolite more efficiently to target cells compared with tenofovir disoproxil fumarate (TDF). Recent studies suggest that TAF is efficacious in treatment naïve individuals who are co-infected with HBV/HIV and may have superior effects on HBV e antigen (HBeAg) seroconversion in this setting. The primary objective of this study was to explore the feasibility of switching from TDF to TAF in HBV/HIV co-infection.

METHODS

In this single-arm, multicenter, open-label study, we recruited patients (n = 20) who were on stable TDF-based antiviral therapy for at least 12 months. All participants had undetectable HIV RNA and HBV DNA levels at the time of screening and were converted to a TAF-based treatment regimen (TAF + emtricitabine + third agent) for 48 weeks.

FINDINGS

Twenty-seven individuals were invited to take part in the screening process; 3 met the exclusion criteria and a further 4 withdrew consent prior to enrolment. The remaining participants were predominantly male (70%), non-cirrhotic (95%) and of Afro-Caribbean ethnicity (60%). All were co-infected with HIV-1 and established on long-term antiretroviral treatment prior to enrolment (median 6.5 years). No adverse events related to the study drug were observed, and most patients (89.5%) maintained undetectable HIV RNA and HBV DNA throughout the follow-up period.

IMPLICATIONS

Switching from TDF to TAF in HBV/HIV co-infection was safe, well tolerated and maintained virological suppression in most patients. Additional studies are needed to confirm these findings in larger cohorts and explore other endpoints.

Divergent effects of the antiretroviral drugs, dolutegravir, tenofovir alafenamide, and tenofovir disoproxil fumarate, on human adipocyte function

Combined antiretroviral therapy (cART) has been associated with increased body weight accompanied by metabolic alterations in people living with human immunodeficiency virus (PLWH). To gain insight into the combined effects of cART components on adipocyte dysfunction, we assessed whether and how treatment of human adipocytes with dolutegravir (DTG) and the nucleotide-analog reverse-transcriptase inhibitors (NRTIs), tenofovir alafenamide (TAF) and tenofovir disoproxil fumarate (TDF), alone and in combination, altered biological processes related to adipose tissue dysfunction. DTG, TAF, and TDF were applied to human Simpson-Golabi-Behmel syndrome (SGBS) adipose cells during differentiation (day 10) and ensuing differentiation (day 14). Expression of selected marker genes was determined by qPCR, the release of adipokines and inflammatory cytokines to the culture media was assessed, and cell respiration was measured. Adipogenesis was not altered by the combined treatment of human adipocytes. However, DTG at the highest dose repressed adipogenesis marker genes expression, and TAF and TDF appeared to mitigate this effect. DTG repressed the expression of adiponectin and the release of adiponectin and leptin in differentiating adipocytes, and these effects were mantained in combination with TAF and TDF. DTG plus TAF or TDF on human adipocytes enhanced inflammation and stress and increased the release of proinflammatory cytokines to the culture media. Together, our results show that combined therapy with these drugs can alter inflammation, cellular stress, and fibrosis in human adipocytes. These findings may improve our understanding and management of the effects of cART on body adiposity and metabolic dysregulation in PLWH.

Review on article of effects of tenofovir alafenamide and entecavir in chronic hepatitis B virus patients

This letter comments on the article which reported that tenofovir alafenamide may increase blood lipid levels compared with entecavir in patients with chronic hepatitis B published on World J Hepatol 2023 August 27. We review the related research content, topic selection, methodology, conclusions, strengths and weaknesses of this article. And evaluate it in relation to other published relevant articles.

Extended post-exposure protection against vaginal SHIV 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 HIV prevention option for women. We recently showed that inserts containing tenofovir alafenamide fumarate (TAF/20mg) and elvitegravir (EVG/16mg) were highly protective against repeated SHIV vaginal exposures when administered to macaques 4h before or after virus exposure (93% and 100%, respectively). Here, we show in the same macaque model that insert application 8h or 24h 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.

Efficacy and safety of tenofovir alafenamide in patients with chronic hepatitis B exhibiting suboptimal response to entecavir

BACKGROUND

Entecavir (ETV) is a potent and safe antiviral agent for patients with chronic hepatitis B (CHB); however, some patients may exhibit suboptimal response or resistance to ETV. Tenofovir alafenamide (TAF) is a novel tenofovir prodrug with improved pharmacokinetics and reduced renal and bone toxicity compared with tenofovir disoproxil fumarate.

AIM

To evaluate the efficacy and safety of switching from ETV to TAF in patients with CHB exhibiting suboptimal response to ETV.

METHODS

A total of 60 patients with CHB who had been treated with ETV for at least 12 mo and had persistent or recurrent viremia [Hepatitis B virus (HBV) DNA ≥ 20 IU/mL] or partial virologic response (HBV DNA < 20 IU/mL, but detectable) were enrolled in the study. The patients were randomly assigned to either continue ETV (0.5 mg) daily or switch to TAF (25 mg) daily for 48 wk. The primary endpoint was the proportion of patients who achieved a virologic response (HBV DNA level < 20 IU/mL) at week 48. Secondary endpoints included changes in serum alanine aminotransferase (ALT), hepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), and anti-HBe levels, and renal and bone safety parameters.

RESULTS

At week 48, the proportion of patients who achieved a virologic response was significantly higher in the TAF group than in the ETV group (93.3% vs 66.7%, P = 0.012). The mean reduction in HBV DNA from baseline was also significantly greater in the TAF group than in the ETV group (-3.8 vs -2.4 Log10 IU/mL, P < 0.001). The rates of ALT normalization, HBeAg loss, HBeAg seroconversion, and HBsAg loss were not found to significantly differ between the two groups. None of the patients developed genotypic resistance to ETV or TAF. Both drugs were well tolerated, with no serious adverse events or discontinuations caused by adverse events. No significant changes were observed in the estimated glomerular filtration rate, serum creatinine level, or urine protein-to-creatinine ratio in either group. The TAF group had a significantly lower decrease in bone mineral density at the lumbar spine and hip than the ETV group (-0.8% vs -2.1%, P = 0.004; -0.6% vs -1.8%, P = 0.007, respectively).

CONCLUSION

Switching from ETV to TAF is effective and safe for patients with CHB exhibiting a suboptimal response to ETV and may prevent further viral resistance and reduce renal and bone toxicity.

Effective prolonged suppression of HIV-1 viral load using tenofovir alafenamide, emtricitabine and efavirenz in an adult with BMI >59 kg/m2

Limited information is available regarding the efficacy of antiretrovirals in people with HIV-1 and high or very high Body Mass Index (BMI). This is especially the case for the alafenamide salt of tenofovir as clinical trials have only enrolled patients with BMI ≤30 kg/m2. Lower concentrations of some antiretrovirals are expected in patients with BMI >30 kg/m2 due to potential changes in clearance and distribution of medication. This report describes an individual taking tenofovir alafenamide, emtricitabine and efavirenz in whom HIV-1 viral load was consistently undetectable (<50 copies/ml) over a 2.5 year period. During this period the patient's BMI ranged between 59.8 and 68.1 kg/m2. Further data is required to support the efficacy of antiretrovirals in individuals with high and very high BMI.

Renal and bone side effects of long-term use of entecavir, tenofovir disoproxil fumarate, and tenofovir alafenamide fumarate in patients with Hepatitis B: a network meta-analysis

BACKGROUND

Nucleoside analogues are currently applied as a first-line treatment for chronic hepatitis B (CHB) patients. However, the long-term effects of this type of treatment on kidney and bone tissue need to be further investigated.

METHODS

We conducted a search of entecavir (ETV), tenofovir disoproxil fumarate (TDF), and tenofovir alafenamide fumarate (TAF) for treatment of CHB patients through October 29, 2023. Side effects of the three drugs were compared. Standardized mean difference (SMD), 95% confidence interval (95%CI), and surface under the cumulative ranking curve (SUCRA) were reported for each outcome. Further subgroup analysis was conducted according to duration of administration.

RESULTS

ETV and TAF exhibited less effect on estimated glomerular filtration rate (eGFR) than TDF (SMD = -3.60 (95%CI: -1.94 ~ -5.26) and SMD = -4.27 (95%CI: -2.62 ~ -5.93)). ETV also exhibited less effect on creatinine rise than TAF and TDF (SMD = -0.55 (95%CI: -0.09 ~ -1.01) and SMD = -0.61 (95%CI: -0.15 ~ -1.06)). Moreover, the effect of TAF on bone mineral density (BMD) was less than that of TDF (SMD = -0.02 (95%CI: -0.01 ~ -0.02)). The probabilities of the three drugs changing relevant indicators exhibited similar patterns: eGFR (TDF (100.0%) > ETV (41.2%) > TAF (8.8%)), creatinine (TDF (94.7%) > TAF (54.7%) > ETV (0.6%)), BMD (TDF (79.7%) > ETV (50.6%) > TAF (19.6%)), and blood phosphorus (TDF (90.6%) > TAF (49.8%) > ETV (9.7%)). After 6 and 24 months of treatment, no statistically significant difference in renal function or bone tissue was observed between ETV and TDF. However, greater adverse effects on renal function were observed for TDF than ETV at 60 months compared to 12 months. TDF also exhibited greater adverse effects on bone tissue than ETV at 36 months than at 12 months.

CONCLUSIONS

Long-term administration of TDF has resulted in stronger adverse effects than TAF and ETV in regard to both renal function and bone tissue in CHB patients. The effect of TAF on creatinine increase was greater than ETV. The difference in side effects between ETV and TDF was independent of treatment duration.

Long-Term Hepatitis B Surface Antigen Profile and Seroclearance Following Antiviral Treatment: A Single-Center, Real-World Cohort Study

Hepatitis B surface antigen (HBsAg) seroclearance, an indicator of recovery from hepatitis B virus (HBV) infection, is uncommon in long-term nucleos(t)ide analog (NUC) therapy. We compared the incidence of HBsAg seroclearance in patients with and without NUC discontinuation to identify predictors of HBsAg seroclearance. This retrospective study enrolled adult patients with a chronic HBV infection followed for ≥12 months after NUC discontinuation (finite group) and those treated with NUCs for >3 years (non-finite group). Demographic, clinical, and laboratory data were analyzed. The study cohort included 978 patients, including 509 and 469 patients in the finite and non-finite groups, respectively. Cumulative HBsAg seroclearance incidence was significantly higher in the finite group than in the non-finite group (p = 0.006). The 5- and 10-year cumulative HBsAg seroclearance incidence were 6.6% and 18.9% in the finite group and 3% and 14.6% in the non-finite group, respectively. The likelihood of HBsAg seroclearance was higher in those with end of treatment (EOT) HBsAg levels of <100 IU/mL and in those without clinical relapse (CR). The cumulative 3-year CR incidence was 16.8%. The incidence of liver decompensation and hepatocellular carcinoma were 4.1 and 0.4 per 1000 person-years, respectively. The hepatocellular carcinoma incidence did not significantly differ between the finite and non-finite groups (p = 0.941). In conclusion, higher HBsAg seroclearance incidence in patients receiving finite therapy, and the increased likelihood of HBsAg seroclearance in those with EOT HBsAg levels of <100 IU/mL and in those without CR should be considered during decision-making of treatment options.

Improved bone and renal safety in younger tenofovir disoproxil fumarate experienced chronic hepatitis B patients after switching to tenofovir alafenamide or entecavir

INTRODUCTION AND OBJECTIVES

Renal and bone impairment has been reported in chronic hepatitis B (CHB) patients receiving long-term tenofovir disoproxil fumarate (TDF) therapy. This study aimed to assess the incidence of renal and bone impairment in CHB patients with long-term TDF therapy and to identify the changes in bone mineral density (BMD) and renal function in these patients after switching to entecavir (ETV) or tenofovir alafenamide (TAF).

MATERIALS AND METHODS

This retrospective study collected clinical data from CHB patients who received TDF monotherapy over 96 weeks. The changes in BMD and renal function were analyzed after 96 weeks of switching antiviral regimens (ETV or TAF) or maintenance TDF.

RESULTS

At baseline, 154 patients receiving TDF monotherapy over 96 weeks were enrolled, with a younger median age of 36.75 years, 35.1% (54/154) of patients experienced elevated urinary β2 microglobulin and 20.1% (31/154) of patients had reduced hip BMD (T<-1). At week 96, among the 123 patients with baseline normal BMD, patients who maintained TDF (n=85) had experienced a decrease in hip BMD, while patients who switched antiviral regimens (n=38) experienced an increase (-13.97% vs 2.34%, p<0.05). Among patients with a baseline reduced BMD (n=31), the alterations in BMD were similar in patients who maintained TDF (n=5) and those who switched antiviral regimens (n=26) (-15.81% vs 7.35%, p<0.05). Irrespective of baseline BMD status, renal function decreased significantly in patients who maintained TDF and improved in patients who switched antiviral regimens.

CONCLUSIONS

Younger CHB patients on long-term TDF therapy are at high risk for bone and renal impairment, with the risk being reduced when switched to ETV or TAF.

Tenofovir alafenamide significantly increased serum lipid levels compared with entecavir therapy in chronic hepatitis B virus patients

BACKGROUND

Tenofovir alafenamide (TAF) has a serum lipid-raising effect in patients with HIV; however, its effect on serum lipids and nonalcoholic fatty liver disease (NAFLD) risk in patients with chronic hepatitis B (CHB) is unclear.

AIM

To compare the effects of TAF and entecavir (ETV) on serum lipid levels in patients with CHB.

METHODS

In this retrospective cohort study, the data including the clinical features, serum lipids, and metabolic factors of patients with CHB at baseline and approximately 1 year after TAF or ETV treatment were collected and analyzed. We used propensity score-matched models to assess the effects on high-density lipoprotein, low-density lipoprotein, triglycerides, and total cholesterol (TCHO).

RESULTS

A total of 336 patients (75.60% male) were included; 63.69% received TAF and 36.31% received ETV. Compared with the ETV group, the TAF group had significantly higher TCHO levels after treatment (4.67 ± 0.90 vs 4.36 ± 1.05, P = 0.006). In a propensity score-matched model for body mass index, age, sex, smoking, drinking, presence of comorbidities such as NAFLD, cirrhosis, diabetes mellitus, and hypertension, TAF-treated patients had significantly increased TCHO levels compared to that at baseline (P = 0.019). There was no difference for the ETV group. Body mass index, sex, hypertension, baseline TCHO, and creatine kinase-MB isoenzyme levels were significantly associated with elevated TCHO levels in logistic regression analysis. However, 1-year TAF treatment did not increase the incidence of NAFLD.

CONCLUSION

A greater increase in TCHO was observed in patients with CHB receiving TAF compared to those receiving ETV. However, TAF-induced dyslipidemia did not increase the incidence of NAFLD.

Risk of dyslipidemia in chronic hepatitis B patients taking tenofovir alafenamide: a systematic review and meta-analysis

BACKGROUND

The aim of this study was to demonstrate how tenofovir alafenamide (TAF) and other hepatitis B treatment drugs differentially impact lipid profiles in chronic hepatitis B patients.

METHODS

We searched PubMed, Ovid MEDLINE, EMBASE, and the Cochrane Library to identify studies on the changes in cholesterol level in hepatitis B patients who underwent TAF therapy. The changes in lipid profiles (e.g., HDL-c, LDL-c, total cholesterol [TC], and triglyceride [TG]) were compared between the TAF treatment group and the baseline, other nucleoside analogs (NAs), and tenofovir disoproxil fumarate (TDF)-only treatment groups. In addition, risk factors for worsening cholesterol level when treated with TAF were examined.

RESULTS

Twelve studies involving 6,127 patients were selected. After 6 months of TAF treatment, LDL-c, TC, and TG were increased by 5.69 mg/dL, 7.89 mg/dL, and 9.25 mg/dL, respectively, from the baseline level. In particular, with the treatment of TAF, levels of LDL, TC, and TG rose by 8.71 mg/dL, 18.34 mg/dL, and 13.68 mg/dL, respectively, showing a greater deterioration of cholesterol when the TAF treatment was implemented compared to other NAs (e.g., TDF or entecavir). When TAF was compared to TDF, LDL-c, TC, and TG worsened with a mean difference of 14.52 mg/dL, 23.72 mg/dL, and 14.25 mg/dL, respectively. As a result of a meta-regression analysis, risk factors for worsening lipid profiles were found to be treatment-experienced, previous diabetes, and hypertension.

CONCLUSIONS

TAF continues to worsen lipid profiles including LDL-c, TC, and TG after 6 months of use compared to the other NAs.

Broadening access to tenofovir alafenamide for the treatment and prevention of HIV-1 infection

INTRODUCTION

Tenofovir alafenamide (TAF), a prodrug of tenofovir, achieves higher intracellular concentrations of tenofovir-diphosphate and 90% lower plasma concentrations of tenofovir compared to tenofovir disoproxil fumarate (TDF). TAF is associated with improved renal and bone safety outcomes.

AREAS COVERED

We review the efficacy and safety of TAF-containing regimens in adults and pediatrics. We highlight safety data during pregnancy, drug interactions during co-administration with tuberculosis treatment, and critical knowledge gaps to be addressed for the successful implementation of TAF in low- and middle-income countries. We performed a search on MEDLINE PubMed and conference websites for relevant articles published from January 2010 to March 2023.

EXPERT OPINION

Current evidence demonstrates that TAF has similar efficacy and tolerability, superior bone and renal safety, and higher rates of dyslipidemia and weight gain, compared with TDF. However, there are several knowledge gaps, in specific sub-populations, that require action. Emerging data suggests that TAF is safe during pregnancy, although fuller safety data to support TAF use in pregnancy is needed. Similarly, there is a lack of evidence that TAF can be used in combination with rifamycin-based tuberculosis treatment in PWH and TB. Further studies are needed to fill knowledge gaps and support the wider rollout of TAF.

Changes in local tissue microenvironment in response to subcutaneous long-acting delivery of tenofovir alafenamide in rats and non-human primates

Several implantable long-acting (LA) delivery systems have been developed for sustained subcutaneous administration of tenofovir alafenamide (TAF), a potent and effective nucleotide reverse transcriptase inhibitor used for HIV pre-exposure prophylaxis (PrEP). LA platforms aim to address the lack of adherence to oral regimens, which has impaired PrEP efficacy. Despite extensive investigations in this field, tissue response to sustained subcutaneous TAF delivery remains to be elucidated as contrasting preclinical results have been reported in the literature. To this end, here we studied the local foreign body response (FBR) to sustained subdermal delivery of three forms of TAF, namely TAF free base (TAF_fb), TAF fumarate salt (TAF_fs), and TAF_fb with urocanic acid (TAF-UA). Sustained constant drug release was achieved via titanium-silicon carbide nanofluidic implants previously shown to be bioinert. The analysis was conducted in both Sprague-Dawley (SD) rats and rhesus macaques over 1.5 and 3 months, respectively. While visual observation did not reveal abnormal adverse tissue reaction at the implantation site, histopathology and Imaging Mass Cytometry (IMC) analyses exposed a local chronic inflammatory response to TAF. In rats, UA mitigated foreign body response to TAF in a concentration-dependent manner. This was not observed in macaques where TAF_fb was better tolerated than TAF_fs and TAF-UA. Notably, the level of FBR was tightly correlated with local TAF tissue concentration. Further, regardless of the degree of FBR, the fibrotic capsule (FC) surrounding the implants did not interfere with drug diffusion and systemic delivery, as evidenced by TAF PK results and fluorescence recovery after photobleaching (FRAP).

An indirect comparison of 144-week efficacy, safety, and tolerability of dolutegravir plus lamivudine and second-generation integrase inhibitor-based, 3-drug, single-tablet regimens in therapy-naive people with HIV-1

BACKGROUND

The long-term efficacy and safety of the 2-drug regimen dolutegravir (DTG) + lamivudine (3TC) and 3-drug single-tablet regimens recommended for antiretroviral therapy (ART)-naive people with HIV-1 (PWH) have yet to be compared directly in clinical trials. This indirect treatment comparison (ITC) was conducted to compare the durability of efficacy and long-term safety of DTG + 3TC vs second-generation, integrase strand transfer inhibitor (INSTI)-based, 3-drug, single-tablet regimens bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) and DTG/abacavir/3TC (DTG/ABC/3TC) at Week 144 after treatment initiation.

METHODS

A systematic literature review identified 4 trials evaluating the treatment regimens of interest in ART-naive PWH (GEMINI-1, GEMINI-2, GS-US-380-1489, and GS-US-380-1490). Safety, efficacy, and tolerability results were compared using fixed-effects Bucher ITC methodology to calculate relative outcomes.

RESULTS

Rates of virologic suppression (HIV-1 RNA < 50 copies/mL, US Food and Drug Administration Snapshot analysis) and virologic failure (HIV-1 RNA ≥ 50 copies/mL) as well as mean change in CD4 + cell count were similar with DTG + 3TC, BIC/FTC/TAF, and DTG/ABC/3TC at Week 144. Serious adverse events occurred less frequently with DTG + 3TC compared with both BIC/FTC/TAF (odds ratio [OR], 0.51; 95% CI 0.29-0.87; P = 0.014) and DTG/ABC/3TC (OR, 0.38; 95% CI 0.19-0.75; P = 0.006). Discontinuations and overall adverse events were similar across all 3 regimens.

CONCLUSIONS

These results suggest that the 2-drug regimen DTG + 3TC offers comparable and durable efficacy with fewer serious adverse events vs BIC/FTC/TAF and DTG/ABC/3TC through 144 weeks of treatment in ART-naive PWH. These long-term comparative data support the therapeutic value of DTG + 3TC for PWH.

HB Surface Antigen Level as a Useful Predictor for the Treatment Response to Tenofovir Alafenamide in Nucleoside Analogue Naïve Chronic Hepatitis B

AIM

To elucidate factors contributing to hepatitis B virus (HBV)-DNA clearance following tenofovir alafenamide (TAF) therapy in nucleoside analogue (NA) naïve patients with chronic hepatitis B (CHB) (n=92, 11 cirrhotic cases).

PATIENTS AND METHODS

The time interval between the start of TAF therapy and first confirmed undetectable HBV-DNA after TAF therapy was calculated. Univariate and multivariate analyses of factors related to undetectable HBV-DNA after TAF therapy were performed.

RESULTS

HB envelop antigen seropositivity was found in 12 patients (13.0%). The cumulative undetectable HBV-DNA rate at 1- and 2- year was 74.9% and 90.9%. In the multivariate Cox regression analysis of the undetectable HBV-DNA after TAF therapy, HBsAg level >1,000 IU/ml (p=0.0082, HBsAg level <100 IU/ml as a reference standard) was an independent predictor of the undetectable HBV-DNA after TAF therapy.

CONCLUSION

Baseline higher HBsAg level can be an adverse predictor for the undetectable HBV-DNA after TAF therapy in NA naïve CHB patients.

HBV relapse rates in patients who discontinue tenofovir disoproxil fumarate with or without switching to tenofovir alafenamide

BACKGROUND/AIMS

The incidence and relapse pattern in patients stopping tenofovir alafenamide (TAF), a prodrug of tenofovir which is more concentrated in hepatocytes, is unknown.

METHODS

HBeAg-negative CHB patients stopping tenofovir disoproxil fumarate (TDF) (off-TDF) or who had switched to TAF more than 3 months before discontinuation (off-TAF) were recruited. The propensity score-matching method (PSM) was used, creating a ratio of 1:3 between the off-TAF versus the off-TDF groups to adjust for associated factors.

RESULTS

After PSM, 180 off-TDF and 60 off-TAF patients were analyzed. The cumulative rates of virological and clinical relapse at 52 weeks were 75.1% and 58.5% respectively in the off-TDF group and 91.1% and 61.6% in the off-TAF group. Patients in the off-TAF group had significantly higher rates of virological relapse than those in the off-TDF group (p = 0.021), but not clinical relapse (p = 0.785). Multivariate cox regression analysis showed that off-TAF group was an independent factor for virological relapse, but not clinical relapse. Severity of clinical relapse and hepatic decompensation rate were comparable between off-TDF and off-TAF groups CONCLUSIONS: The off-TAF group had a higher virological relapse rate than the off-TDF group. The difference in clinical relapse pattern and severity was not clinically important between the two groups.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Young age is a key determinant of body weight gain after switching from tenofovir disoproxil fumarate to tenofovir alafenamide in Japanese people living with HIV

BACKGROUND

Treatment with tenofovir alafenamide fumarate (TAF) is associated with body weight gain. However, little or no information is available on this issue in Asian populations.

METHODS

This single-center retrospective study included Japanese people living with HIV (PLWH) who satisfied the following criteria; 1) switching from TDF to TAF after HIV-suppression, 2) follow-up for ≥2 years while on TDF and TAF, and 3) no switching of the third antiretroviral agent. Changes in annual body weight and lipid profiles were compared between the TDF and TAF periods.

RESULTS

Of 328 patients, dolutegravir (DTG) was used in 118 PLWH. Overall, no significant difference in weight gain was observed between TDF and TAF (0.76 vs. 0.9 kg/year, p = 0.331). In TAF-period, younger (<50 years of age) group showed significantly greater weight gain than older group (1.03 vs. 0.12 kg/year, p = 0.037). In DTG group, weight gain was larger in TAF-period (0.74 vs. 1.31 kg/year, p = 0.046), especially in younger subgroup (1.43 kg/year) compared with older one (-0.12 kg/year). Multivariate regression analysis showed that TAF was not associated with weight gain (estimates 0.201, p = 0.170) except for DTG group, whereas young age was associated with weight gain in all subjects (estimates -0.033/1 year older, p < 0.001), DTG, RAL, and EFV groups.

CONCLUSION

In Japanese PLWH, annual body weight change was comparable in TDF- and TAF-period, while TAF plus DTG correlated with weight gain. Since young age was a key determinant of weight change, careful interpretation is needed for TAF-associated weight gain.

Preliminary Evaluation of Stability Data for Dolutegravir-Containing Triple Active Formulations Intended for PEPFAR. Degradation of Tenofovir Disoproxil Fumarate and Tenofovir Alafenamide as the Limiting Factor

FDA reviews applications that are filed under the PEPFAR program to ensure that these products are manufactured to FDA's stringent requirements. Dolutegravir is a comparatively recent molecular entity that represents an advance over previous products. The stability behaviors of tablets that contain dolutegravir, lamivudine, and tenofovir disoproxil fumarate and tablets that contain dolutegravir, emtricitabine and tenofovir alafenamide were surveyed and it was found that tenofovir-related degradants increase the most and are the parameters most likely to result in product failure. A desiccant is advantageous and this desiccant should remain in the bottle after it has been opened. In-use studies simulate consumer use. Bottles are stored at 30 °C/75% RH and opened for about 1 min a day. Water content increased significantly and the rate of degradation was faster than the degradation rate observed during long-term storage. The data predict that most formulations containing TDF will stay within specification over 4 years of long-term storage followed by dispensing one tablet per day. With the current data it appears that some TAF-containing formulations may fail under similar conditions. However, the data are limited and preliminary and it is possible that the situation may improve as more stability data are acquired.

Single dose topical inserts containing tenofovir alafenamide fumarate and elvitegravir provide pre- and post-exposure protection against vaginal SHIV infection in macaques

BACKGROUND

Vaginal products for HIV prevention that can be used on-demand before or after sex may be a preferable option for women with low frequency or unplanned sexual activity or who prefer not to use daily or long-acting pre-exposure prophylaxis (PrEP). We performed dose ranging pharmacokinetics (PK) and efficacy studies of a vaginally applied insert containing tenofovir alafenamide fumarate (TAF) and elvitegravir (EVG) in macaques under PrEP or post-exposure prophylaxis (PEP) modalities.

METHODS

PK studies were performed in 3 groups of pigtailed macaques receiving inserts with different fixed-dose combinations of TAF and EVG (10/8, 20/16 and 40/24 mg). PrEP and PEP efficacy of a selected insert was investigated in a repeat exposure vaginal SHIV transmission model. Inserts were administered 4 h before (n = 6) or after (n = 6) repeated weekly SHIV exposures. Infection outcome was compared with macaques receiving placebo inserts (n = 12).

FINDINGS

Dose ranging studies showed rapid and sustained high drug concentrations in vaginal fluids and tissues across insert formulations with minimal dose proportionality. TAF/EVG (20/16 mg) inserts were selected for efficacy evaluation. Five of the 6 animals receiving these inserts 4 h before and 6/6 animals receiving inserts 4 h after SHIV exposure were protected after 13 challenges (p = 0.0088 and 0.0077 compared to placebo, respectively). The calculated PrEP and PEP efficacy was 91.0% (95% CI = 32.2%-98.8%) and 100% (95% CI = undefined), respectively.

INTERPRETATION

Inserts containing TAF/EVG provided high protection against vaginal SHIV infection when administered within a 4 h window before or after SHIV exposure. Our results support the clinical development of TAF/EVG inserts for on-demand PrEP and PEP in women.

FUNDING

Funded by CDC intramural funds, an interagency agreement between CDC and USAID (USAID/CDC IAA AID-GH-T-15-00002), and by the U.S. President's Emergency Plan for AIDS Relief (PEPFAR) through the U.S. Agency for International Development (USAID) under a Cooperative Agreement (AID-OAA-A-14-00010) with CONRAD/Eastern Virginia Medical School.

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.

Evidence synthesis evaluating body weight gain among people treating HIV with antiretroviral therapy - a systematic literature review and network meta-analysis

Background

This systematic review aimed to compare body weight gain associated outcomes over time between dolutegravir (DTG)-based antiretroviral (ART) regimens to other ART regimens, to compare tenofovir alafenamide (TAF)-based regimens, and to evaluate the associated prognostic factors.

Methods

Systematic searches of MEDLINE, Embase, and CENTRAL for RCTs and observational studies comparing ART regimens were conducted on 13 September 2021. Outcomes of interest included: change in body weight, body mass index (BMI), waist circumference; and risk of hyperglycaemia and diabetes. Network meta-analyses were conducted at 12, 24, 48, 96 and 144 weeks using two networks differentiated by 3rd agents and backbone agents.

Findings

The review identified 113 publications reporting on 73 studies. DTG-based regimens led to statistically higher weight gains than efavirenz-based regimens at all time points (mean difference: 1·99 kg at 96 weeks; 95% credible interval: 0·85-3·09) and was higher over time than low-dose efavirenz-, elvitegravir-, and rilpivirine-based regimens. They were comparable to raltegravir-, bictegravir- and atazanavir-based regimens. For backbones, TAF led to higher weight gain relative to tenofovir disoproxil fumarate (TDF), abacavir, and zidovudine. Prognostic factor analysis showed both low CD4 cell count and high HIV RNA viral load at baseline were consistently associated with higher weight gain, while sex was an effect modifier to African origins.

Interpretation

DTG-based regimens lead to larger average weight gains than some other ART regimens and TAF leads to larger average weight gains than all other backbone antiretrovirals. Further research is needed to better understand long-term outcomes and their relationship to other metabolic outcomes.

Funding

The WHO Global HIV, Hepatitis and Sexually Transmitted Infections Programmes.

Tenofovir alafenamide is associated with improved alanine aminotransferase and renal safety compared to tenofovir disoproxil fumarate

BACKGROUND & AIMS

Tenofovir alafenamide (TAF) is a novel prodrug of tenofovir for the treatment of chronic hepatitis B (CHB) infection. We aimed to evaluate the impact of switching to TAF on alanine aminotransferase (ALT) normalization and renal safety. We also described the indications of switching to TAF.

METHODS

Consecutive adult CHB patients switched from tenofovir disoproxil fumarate (TDF) dominant therapy to TAF for more than 12 months were identified retrospectively. A subgroup of patients newly switched to TAF were prospectively invited to perform transient elastography examination and dual-energy X-ray absorptiometry. The time of switching to TAF was defined as baseline.

RESULTS

Among 393 patients in the retrospective cohort, the median ALT at month 12 was significantly lower (21.0 [16.0 - 29.9] U/L vs. 25.0 [19.0 - 34.0] U/L; P < 0.001) and ALT normalization rate was higher (89.9% vs. 83.7%; P = 0.037) than those at baseline. Estimated glomerular filtration rate decreased from 12 months before baseline and then increased from baseline to month 12 significantly (69.7 ± 22.0 mL/min/1.73m² vs. 68.5 ± 21.5 mL/min/1.73m² vs. 69.2 ± 21.5 mL/min/1.73m² , P = 0.002 (-12m vs. baseline), P = 0.004 (baseline vs. 12m)). In the prospective cohort, 103 patients switched to TAF because of age > 60 years (63.1%), bone diseases (54.4%) and renal alteration (42.7%).

CONCLUSION

TAF is associated with ALT improvement and better renal safety than TDF dominant therapy in CHB patients. Most CHB patients switched to TAF because of advanced age, followed by bone disease and renal alteration. This article is protected by copyright. All rights reserved.

Effectiveness of Tenofovir Alafenamide in Chronic Hepatitis B Patients with Normal Alanine Aminotransferase and Positive Hepatitis B Virus DNA

BACKGROUND AND AIMS

With an increasing understanding of hepatitis B, the antiviral indications have been broadening gradually. To evaluate the effectiveness of tenofovir alafenamide (TAF) in chronic hepatitis B (CHB) patients with normal alanine aminotransferase (ALT) and detectable hepatitis B virus (HBV) DNA, those who are ineligible for broader antiviral criteria from the Chinese CHB prevention guide (2019).

METHODS

A total of 117 patients were recruited and their data were collected from paper or electronic medical records. HBV DNA and liver function were measured at baseline and throughout the 24-week follow-up. The effectiveness endpoint was complete virological response. The safety endpoint was the first occurrence of any clinical adverse event during the treatment.

RESULTS

Among the 117 patients, 45 had normal ALT as well as detectable HBV DNA and they were not recommended for antiviral therapy according to Chinese Guidelines (2019). After TAF antiviral therapy, the rates of patients who achieved HBV DNA <20 IU/mL at 4, 12 and 24 weeks were 77.1%, 96.7% and 96.8% respectively. Among them, the undetectable rates of HBV DNA in patients with low baseline viral load at 4, 12 and 24 weeks were 92.3%, 100% and 100%, while the rates of those with high baseline viral load were 68.2%, 94.1% and 94.4%. Compared with 71.4%, 94.4% and 94.7% in the high baseline group, the undetectable rates of HBV DNA at 4, 12 and 24 weeks in the low baseline liver stiffness group were 85.7%, 100% and 100%. There was no statistical significance among the above groups.

CONCLUSIONS

CHB patients who had normal ALT and detectable HBV DNA and did not meet "CHB prevention guide (2019)", could achieve complete virological response in 24 weeks after antiviral treatment by TAF.

Real-world experience of switching from tenofovir disoproxil fumarate to tenofovir alafenamide in patients with chronic hepatitis B: a retrospective study

Background

Tenofovir alafenamide (TAF) has good viral suppression efficacy and less adverse effect than tenofovir disoproxil fumarate (TDF). Real-world studies on the antiviral efficacy and safety of switching from TDF to TAF in patients with chronic hepatitis B (CHB) are limited.

Methods

This retrospective study included 167 nucleos(t)ide analogue (NA)-naive patients with CHB. All the patients received TDF at least 12 months before switching and TAF at least 12 months after switching at a single medical center. The Friedman test with Dunn–Bonferroni post hoc tests and repeated-measures analysis of variance was used to analyze the effect of complete viral suppression, alanine aminotransferase (ALT) level normalization, renal function changes, body weight, and body mass index in the periods before and after switching.

Results

The mean age and TDF treatment duration were 52 ± 11 years and 2.8 years (interquartile range, 1.51–5.15 years), respectively. The complete viral suppression rate was similar between the time of switching and 48 weeks after switching to TAF (77.8% vs 76%, P = 1.000). The percentage of alanine aminotransferase (ALT) normalization increased from 26.3% at TDF start to 81.4% (P < 0.001) at time of switching and 89.2% at 48 weeks after switching to TAF (P = 0.428). The median estimated glomerular filtration rate decreased from 100.09 mL/min/1.73 m² at TDF start to 91.97 mL/min/1.73 m² (P < 0.001) at the time of switching and stabilized at 48 weeks after switching to TAF (93.47 mL/min/1.73m², P = 1.000). The body weight decreased from 69.2 ± 12.2 kg at TDF start to 67.4 ± 12.1 kg (P < 0.001) at the time of switching to TAF and returned to 68.7 ± 12.7 kg (P < 0.001) 48 weeks thereafter. The body mass index (BMI) decreased from 25 ± 3.3 kg/m² at TDF start to 24.5 ± 3.3 kg/m² (P = 0.002) at the time of switching to TAF and returned to 25.1 ± 3.6 kg/m² (P < 0.001) 48 weeks thereafter.

Conclusions

Our study showed that switching to TAF from TDF had good antiviral effectiveness and stabilized renal function. The body weight and BMI decreased during TDF therapy and regained after switching to TAF.

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.

Effectiveness of tenofovir alafenamide for chronic hepatitis B patients with a poor response to the previously used nucleos(t)ide analogs

BACKGROUND

Few studies have demonstrated the potency of tenofovir alafenamide (TAF) in patients with poor response to other nucleos(t)ide analogs (NAs).

METHODS

We conducted a retrospective study comprising consecutive 40 patients exhibiting a poor response to other NAs, who subsequently received TAF-containing regimens. The primary outcome was the prevalence of virological response (VR) at each time and maintained virological response (MVR) under TAF-containing regimens until week 96.

RESULTS

In the entire cohort, the prevalence of MVR was 71.1% (27/38). Further, poor tenofovir disoproxil fumarate (TDF) response was significantly associated with a lower prevalence of MVR (p = 0.014). In TDF-naïve patients, the prevalence of MVR was 92.3% (12/13) and 62.5% (5/8) in patients with lamivudine resistance (LAM-r) and entecavir resistance (ETV-r), respectively. Further, viral load and HBeAg status at baseline were associated with a lower prevalence of MVR (p = 0.013). Among the seven patients with prior TDF exposure, 2 patients achieved MVR. Among them, one patient with development of viral breakthrough during TDF/LAM achieved MVR after switching to TAF/ETV. In contrast, one of the five patients with non-MVR had three substitutions (rtS106C, rtD134N/S, and rtL269I) of quadruple mutations in addition to ETV-r. Other patients with rtA181T + rtN236T also could not achieve MVR.

CONCLUSION

TAF exhibited high antiviral potency in patients with LAM-r and ETV-r. However, TAF potency was associated with previous TDF response, viral load, and HBeAg status at baseline. Additionally, a quadruple mutation may impact tenofovir resistance; however, further studies are needed to verify this.

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

BACKGROUND/PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Asociación Mexicana de Hepatología A.C. Clinical guideline on hepatitis B

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

Impact of switch from tenofovir disoproxil fumarate-based regimens to tenofovir alafenamide-based regimens on lipid profile, weight gain and cardiovascular risk score in people living with HIV

Background

As cardiovascular diseases represent the main cause of non-AIDS related death in people living with HIV (PLWH) with undetectable viral load, we evaluated lipid profile, weight gain and calculated cardiovascular risk change after switching from tenofovir disoproxil fumarate (TDF)-based regimens to tenofovir alafenamide (TAF)-based regimens.

Methods

For this retrospective study, we selected HIV-infected patients with suppressed viral load who fitted in one of the two groups below: First group (TDF/TDF): Patients treated continuously with TDF-based regimens. Second group (TDF/TAF): Patients treated with TDF-regimens during at least 6 months then switched to TAF-regimens while maintaining other drugs unchanged. Available data included date of birth, gender, ethnicity, lymphocyte T CD4⁺ count, weight, height, blood pressure, current/ex/non-smoker, diabetes mellitus, familial cardiovascular event, lipid profile, duration and nature of antiretroviral therapy. Lipid parameters, weight and calculated cardiovascular risk using 5-year reduced DAD score algorithm [Friis-Møller et al. in Eur J Cardiovasc Prev Rehabil 17:491–501, 2010] were analyzed in each groups.

Results

Switching from TDF to TAF resulted in a significant increase in triglycerides levels, total cholesterol and HDL cholesterol. LDL cholesterol and total cholesterol/HDL ratio did not show significant changes. Calculated cardiovascular risk increased after switch from TDF- to TAF-based therapy.

Conclusions

Together with favorable outcomes at the bone and kidney levels, potential negative impact of TAF on lipid profile should be included in the reflection to propose the most appropriate and tailored ARV treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06479-9.

Comparison of weight gain after antiretroviral switch to integrase strand transfer inhibitor or tenofovir alafenamide-based therapy

PURPOSE

Several studies have reported weight gain after switching to integrase strand transfer inhibitor (INSTI)-based antiretroviral therapy (ART). Debate persists if weight gain also occurs when switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF)-based ART.

METHODS

We performed a retrospective chart review of virally suppressed HIV-infected patients who were switched from non INSTI- to INSTI-based ART (INSTI switch group) as well as patients switched from TDF- to TAF-based ART (TAF switch group), and compared the mean weight change in these groups to the mean change in weight in patients maintained on NNRTI-based regimens (control group).

RESULTS

329 patients were identified. 256 patients in the INSTI switch group gained a mean 2.4 kg over 17 months compared to 0.5 kg in 54 patients in the control group over the same period (p = 0.008). 161 patients in the TAF switch group gained a mean 2.8 kg over 17 months compared to 0.5 kg in the control group (p = 0.003). There was no statistical difference in weight gain between the INSTI and TAF switch groups. Although the highest mean weight gain of 3.2 kg was seen in those 90 patients switched from both TDF- to TAF-based and non INSTI- to INSTI-based ART (TAF/INSTI switch group), this weight gain was not statistically different compared with the INSTI switch or TAF switch groups.

CONCLUSION

Our study suggests that weight gain is associated with both switching HIV regimens from non INSTI- to INSTI-based ART and TDF- to TAF-based ART.

Tenofovir alafenamide nephrotoxicity: a case report and literature review

Background

Tenofovir alafenamide (TAF), a novel prodrug of tenofovir (TFV), has become the preferred drug for the treatment of HIV-1 and chronic hepatitis B infection in clinical practice. Results from clinical trials showed that it had better renal and bone mineral outcomes compared to tenofovir disoproxil fumarate (TDF). However, as we have seen with TDF, side effects from the new medication can be more prevalent and recognized after extensive use in real world situations. Sporadic cases of acute kidney injury in patients using TAF have started to emerge.

Case presentation

We report a case of 49-year-old Thai, HIV treatment-experienced female with hypertension presented with worsening renal function after switching her antiretroviral regimen from TDF, emtricitabine (FTC), and lopinavir/ritonavir (LPV/r) to TAF, FTC and dolutegravir (DTG) for 3 months. Kidney biopsy showed distinctive picture of tenofovir nephrotoxicity with acute tubular injury and mitochondrial injury. The possible causes of acute kidney injury and nephrotoxicity from TAF for this patient were discussed. We have extensively reviewed all published case reports of TAF-associated nephrotoxicity and summarized the essential information in this article.

Conclusion

Although TAF has less nephrotoxicity compared with TDF; renal function should always be monitored after the initiation of both drugs. Future large cohort studies are required to identify the risk factors of TAF-associated nephrotoxicity and to design an effective preventive strategy.

entecavir on hepatocellular carcinoma risk in patients with chronic hepatitis B

BACKGROUND AND AIMS

Whether entecavir (ETV) or tenofovir alafenamide (TAF) is better at preventing hepatocellular carcinoma (HCC) development among patients with chronic hepatitis B (CHB) remains unclear. The present study was conducted to explore the ability of these two antivirals to prevent HCC.

METHODS

From 2012 to 2019, treatment-naïve CHB patients undergoing ETV or TAF therapy were recruited at three academic teaching hospitals. The TAF group comprised patients starting TAF as first-line antiviral and those switching antivirals from tenofovir disoproxil fumarate to TAF. Patients with decompensated cirrhosis or HCC at enrollment were excluded from the analysis. Cumulative probabilities of HCC were assessed using the Kaplan-Meier method.

RESULTS

In total, 1810 patients (1525 and 285 in ETV and TAF groups, respectively) were recruited. The annual HCC incidence was statistically not different between the ETV and TAF groups (1.67 vs. 1.19 per 100 person-years, respectively) with an adjusted hazard ratio (HR) of 0.681 (p = 0.255), as determined by multivariate analysis. Male, hypertension, liver cirrhosis, FIB-4 index, and albumin were independent prognostic factors for HCC development. Propensity score-matched and inverse probability of treatment weighting analyses yielded similar results, with non-statistically different HCC incidence between the ETV and TAF groups (1.07 vs. 1.19 per 100 person-years (HR = 0.973; p = 0.953) and 1.67 vs. 1.89 per 100 person-years, respectively (HR = 0.949; p = 0.743).

CONCLUSIONS

These findings suggest that ETV- and TAF-treated CHB patients have similar risk of developing HCC. Further studies with the larger sample size and longer follow-up are needed to validate these results.

Asociación Mexicana de Hepatología A.C. Clinical guideline on hepatitis B

Hepatitis B virus (HBV) infection continues to be a worldwide public health problem. In Mexico, at least three million adults are estimated to have acquired hepatitis B (total hepatitis B core antibody [anti-HBc]-positive), and of those, 300,000 active carriers (hepatitis B surface antigen [HBsAg]-positive) could require treatment. Because HBV is preventable through vaccination, its universal application should be emphasized. HBV infection is a major risk factor for developing hepatocellular carcinoma. Semi-annual liver ultrasound and serum alpha-fetoprotein testing favor early detection of that cancer and should be carried out in all patients with chronic HBV infection, regardless of the presence of advanced fibrosis or cirrhosis. Currently, nucleoside/nucleotide analogues that have a high barrier to resistance are the first-line therapies.

Weight gain in HIV-infected individuals using distinct antiretroviral drugs

Following the initiation of antiretroviral therapy, most HIV-infected individuals experience significant weight gain. It was originally thought to result from reduced energy consumption associated with suppression of overt virus replication. However, recent evidence suggests that is not simply a back to normal phenomenon. Indeed, a differential influence on weight has been noticed for distinct antiretroviral drugs, some of which may produce abnormal body weight gain and metabolic disturbances. Treatment with integrase inhibitors in particular leads to significant increases in body mass index. By contrast, protease inhibitors might protect from undesirable weight gain. Ultimately, the development of overweight and obesity in an aging HIV population may increase the risk of cardiovascular events and should be prevented. In this scenario, the differential influence on weight gain using distinct antiretroviral agents might provide an opportunity for personalized medicine, adapting the most convenient drug regimen to each patient.

Tenofovir Alafenamide Fumarate, Tenofovir Disoproxil Fumarate and Entecavir: Which is the Most Effective Drug for Chronic Hepatitis B? A Systematic Review and Meta-analysis

BACKGROUND AND AIMS

The therapeutic effect of tenofovir alafenamide fumarate (TAF), tenofovir disoproxil fumarate (TDF) and entecavir (ETV) on chronic hepatitis B (CHB) patients remains inconsistent. The aim of this study was to explore the differences in virological responses to TAF, TDF and ETV in patients with CHB.

METHODS

Literature searches were conducted of the PubMed, EMBASE, and the Cochrane Library databases to identify randomized controlled trials and observational studies published up to July 21, 2020. Statistical comparisons of virological response between TDF, ETV, and TAF were carried out with pooled odds ratio (OR) values.

RESULTS

The virological response in TDF-treated CHB patients was notably superior to that of the ETV-treated CHB patients after 12-weeks [OR=1.12, 95% confidence interval (CI): 0.89-1.41], 24-weeks (OR=1.33, 95% CI: 1.11-1.61), 48-weeks (OR=1.62, 95% CI: 1.16-2.25), 72-weeks (OR=1.43, 95% CI: 0.78-2.62), and 96-weeks (OR=1.56, 95% CI: 0.87-2.81) treatment. No significant difference was observed for the virological responses in CHB patients after 48-weeks treatment with TAF or TDF. The virological response in TDF+ETV-treated CHB patients was superior to that of TDF-treated CHB patients after 24-weeks, 48-weeks (OR=1.54, 95% CI: 1.17-2.02), 96-weeks, and 144-weeks.

CONCLUSIONS

The virological response in TDF-treated CHB patients was superior to that in ETV-treated CHB patients, but there was no significant difference between TAF and TDF. In addition, the therapeutic effect of TDF+ETV was superior to TDF alone.

Impact of switching to TAF/FTC/RPV, TAF/FTC/EVG/cobi and ABC/3TC/DTG on cardiovascular risk and lipid profile in people living with HIV: a retrospective cohort study

BACKGROUND

We aimed to assess the overall cardiovascular and metabolic effect of the switch to three different single tablet regimens (STRs) [tenofovir alafenamide/emtricitabine/rilpivirine (TAF/FTC/RPV), TAF/FTC/elvitegravir/cobi (TAF/FTC/EVG/cobi) and ABC/lamivudine/dolutegravir (ABC/3TC/DTG)] in a cohort of people living with HIV/AIDS (PLWH) under effective ART.

METHODS

All PLWH aged above 18 years on antiretroviral treatment with an HIV-RNA < 50 cp/mL at the time of the switch to TAF/FTC/RPV, TAF/FTC/EVG/cobi and ABC/3TC/DTG were retrospectively included in the analysis. Framingham risk score modification after 12 months from the switch such as lipid profile and body weight modification were assessed. The change from baseline to 12 months in mean cardiovascular risk and body weight in each of the STR's group were assessed by means of Wilcoxon signed-rank test whereas a mixed regression model was used to assess variation in lipid levels.

RESULTS

Five-hundred and sixty PLWH were switched to an STR regimen of whom 170 (30.4%) to TAF/FTC/EVG/cobi, 191 (34.1%) to TAF/FTC/RPV and 199 (35.5%) to ABC/3TC/DTG. No difference in the Framingham cardiovascular risk score was observed after 12 months from the switch in each of the STR's groups. No significant overtime variation in mean total cholesterol levels from baseline to 12 months was observed for PLWH switched to ABC/3TC/DTG [200 (SD 38) mg/dl vs 201 (SD 35) mg/dl; p = 0.610] whereas a significant increment was observed in PLWH switched to TAF/FTC/EVG/cobi [192 (SD 34) mg/dl vs 208 (SD 40) mg/dl; p < 0.0001] and TAF/FTC/RPV [187 (SD 34) mg/dl vs 195 (SD 35) mg/dl; p = 0.027]. In addition, a significant variation in the mean body weight from baseline to 12 months was observed in PLWH switched to TAF/FTC/EVG/cobi [72.2 (SD 13.5) kilograms vs 74.6 (SD 14.3) kilograms; p < 0.0001] and TAF/FTC/RPV [73.4 (SD 11.6) kilograms vs 75.6 (SD 11.8) kilograms; p < 0.0001] whereas no difference was observed in those switched to ABC/3TC/DTG [71.5 (SD 12.8) kilograms vs 72.1 (SD 12.6) kilograms; p = 0.478].

CONCLUSION

No difference in the cardiovascular risk after 1 year from the switch to these STRs were observed. PLWH switched to TAF/FTC/EVG/cobi and TAF/FTC/RPV showed an increase in total cholesterol levels and body weight 12 months after the switch.

Short-term and long-term safety and efficacy of tenofovir alafenamide, tenofovir disoproxil fumarate and entecavir treatment of acute-on-chronic liver failure associated with hepatitis B

Background & Aims

There is limited evidence on the efficacy and safety of nucleos(t) ide analogues (NAs) in the treatment of HBV-ACLF. Our objective was to evaluate the outcomes among TAF, TDF and ETV, three first-line antivirals against chronic hepatitis B, in patients with HBV-ACLF.

Methods

Patients with HBV-related ACLF were recruited and received daily TAF (25 mg/d), TDF (300 mg/d) and ETV (0.5 mg/d). They were prospectively followed-up. The primary endpoint was overall survival at week 12 and week 48, the secondary endpoints were virological response and biochemical response.

Results

Forty gender and age matched eligible subjects were recruited and divided into three groups: TAF group, TDF group and ETV group. By week 48, 8 (80%) patients in TAF group, 6 (60%) patients in TDF group and 17 (85%) patients in ETV group survived without liver transplantation (P = 0.251). After 4 weeks of NAs treatment, all three groups showed paralleling reduction of HBV DNA levels. All three groups presented similar biochemical responses at week 4, patients treated with TAF showed a priority in total bilirubin reduction, albumin and cholesterol maintenance. Additionally, although there was no significant difference in changes of serum urea, serum creatinine, serum cystatin C and estimated GFR among the three groups by treatment week 4, TDF showed unfavorable renal safety even in short -term treatment. The treatment using NAs was well-tolerated and there was no serious drug-related adverse event reported.

Conclusions

TAF, TDF and ETV are of similar efficacy and safety in short-term and long-term treatment of HBV-ACLF.

Trial registration

This study is ongoing and is registered with ClinicalTrials.gov, NCT03640728 (05/02/2019).

Changing trends in lipid profile and biomarkers of renal function and bone metabolism before and after switching from tenofovir disoproxil fumarate to tenofovir alafenamide: a prospective observational study

Background

Antiretrovirals, including tenofovir, can suppress human immunodeficiency virus (HIV) infection but cannot completely eradicate it. Patients with HIV infection are administered antiretroviral drugs over a long term; thus, managing consequent adverse drug reactions, such as renal dysfunction and bone mineral loss, is important. Currently, highly sensitive biomarkers that can detect adverse drug reactions early have not been well studied.

Methods

This single-center, prospective, observational study explored changes in the biomarkers of renal function, bone metabolism, and lipid profile before and after switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF) in patients with HIV infection.

Results

All 31 enrolled patients had been treated with antiretrovirals for more than 5 years. The rate of proteinuria decreased significantly after starting TAF-containing antiretroviral regimen. The urinary liver-type fatty acid binding protein (L-FABP)/creatinine ratio was significantly decreased at 3 and 6 months after switching to TAF compared with that before switching to TAF (− 0.5 μg/g Cr at 3 months, and − 0.8 μg/g Cr at 6 months; p < 005 for both at 3 and 6 months). The urinary N-terminal telopeptide (NTx)/creatinine ratio decreased over the study period, and the ratios were significantly different between 3 and 6 months (− 11 nmol/mmol Cr at 3 months, − 15.2 nmol/mmol Cr at 6 months; p = 0.0069 at 3 months, p < 0.0001 at 6 months). Low density lipoprotein-cholesterol level significantly increased at 3 (+ 26 mg/dL) and 6 months (+ 13 mg/dL) compared with that at the baseline (p < 0.0001).

Conclusions

Switching from TDF to TAF decreased the levels of renal and bone biomarkers, such as urinary L-FABP and NTx, but increased low density lipoprotein-cholesterol levels. Future studies should evaluate if these biomarkers, such as urinary L-FABP and NTx, truly detect serious adverse drug reactions early.

Marketing of Tenofovir Disoproxil Fumarate (TDF) Lawsuits and Social Media Misinformation Campaigns' Impact on PrEP Uptake Among Gender and Sexual Minority Individuals

There has been an influx of ads on social media seeking plaintiffs in lawsuits for harms/side-effects caused by tenofovir disoproxil fumarate/Emtricitabine (TDF/FTC, Truvada) for PrEP. Community groups and researchers have suggested these ads may be undermining efforts to disseminate PrEP to key populations. In October 2019, we began assessing the impact of injury lawsuit ads on social media platforms in an ongoing U.S. national cohort study of HIV-negative cis men, trans men, and trans women who have sex with men. Although assessments are ongoing, given the alarming nature of our findings, we report data collected as of March 2020 (n = 2078). Most (59.9%) said they had seen ads for TDF-related lawsuits on social media. Twenty-eight percent said they would probably or definitely not start PrEP and 22.1% said they would not stay on PrEP (were they on it) as a result of seeing these ads. Next, 38.2% agreed or strongly agreed that seeing these ads made them think that TDF/FTC for PrEP was not safe. Black, Latinx, and/or multiracial individuals were most likely to be negatively impacted by the ads including perceptions that these ads made them think PrEP is not safe. In contrast, past year experience taking PrEP was positively associated with intentions to start and/or stay on PrEP despite seeing the ads. Due to forthcoming affordable/generic options, TDF/FTC is projected to become the most scalable option for disseminating PrEP to key populations. Results suggest that ads for TDF lawsuits on social media are having a negative impact on individual PrEP decision-making. Our findings highlight the urgency for accurate and balanced messaging on the benefits and risks of PrEP, so that individuals can make informed choices about whether PrEP is right for them.

Bictegravir/Emtricitabine/Tenofovir Alafenamide in Virologically Suppressed People with HIV Aged ≥ 65 Years: Week 48 Results of a Phase 3b, Open-Label Trial

Introduction

We report the 48-week results of an ongoing study to assess the efficacy and safety of switching older people with HIV to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF).

Methods

This was a 96-week, phase 3b, open-label, single-arm study (GS-US-380-4449; NCT03405935). Virologically suppressed individuals aged ≥ 65 years receiving elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide or a tenofovir disoproxil fumarate-based regimen were switched to B/F/TAF. Primary endpoint was the percentage of participants with HIV-1 RNA < 50 copies/ml at week 24.

Results

Eighty-six participants (median age 69 [range 65–80] years; 87% male; 95% white) were enrolled and treated in five European countries. Rates of virologic suppression were 97.7% at week 24 and 90.7% at week 48; none had HIV-1 RNA ≥ 50 copies/ml, and 100% had virologic suppression by missing = excluded analysis at both time points. No treatment-emergent resistance was observed. There were no grade 3–4 study drug-related adverse events (AEs) or study drug-related serious AEs or deaths. Three AEs led to premature discontinuation; one (moderate abdominal discomfort) was attributed to the study drug by the investigator. At week 48, median changes from baseline in weight and estimated glomerular filtration rate were + 0.1 kg (interquartile range [IQR] − 1.0, 2.3) and − 6.0 ml/min (IQR − 10.2, 0.0), respectively. There were no clinically relevant changes from baseline to week 48 in fasting lipid parameters. Treatment satisfaction improved, and health-related quality of life was maintained from baseline through week 48. Median adherence to the study drug was 98.6% (IQR 96.0, 100).

Conclusions

Switching to B/F/TAF was effective and well tolerated through 48 weeks in virologically suppressed adults aged ≥ 65 years.

Trial Registration

ClinicalTrials.gov identifier, NCT03405935.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00419-5.

Patient-Focused Selection of PrEP Medication for Individuals at Risk of HIV: A Narrative Review

Pre-exposure prophylaxis (PrEP) medication is a key component of the HIV prevention strategy in the US, which has been demonstrated to be highly effective in preventing HIV acquisition among individuals at risk. Two PrEP medications are currently approved: emtricitabine/tenofovir disoproxil fumarate (Truvada®; F/TDF) was approved by the US Food and Drug Administration in 2012, followed by emtricitabine/tenofovir alafenamide (Descovy®; F/TAF) in 2019. An ongoing randomized, double-blind, Phase 3 study (DISCOVER) demonstrated that F/TAF had non-inferior efficacy to F/TDF. While both medications have been found to be efficacious and well tolerated, several studies have identified that important differences exist with regards to pharmacokinetics, bone and renal safety profiles, and other factors. In this narrative review, we conducted a comprehensive evaluation of the populations at risk of HIV who may also be affected by, or at risk of, bone or renal conditions. We reviewed the safety profiles of F/TDF and F/TAF to develop an evidence-based algorithm for selecting the appropriate PrEP medication, based on biological, behavioral, and health characteristics of an individual at risk of HIV, and considered how the choice of PrEP medication may or may not compound safety concerns for these individuals. We identified that the introduction of F/TAF provides a valuable alternative to F/TDF, allowing the personalization of PrEP. F/TAF may be the preferred medication for cisgender men and transgender women at risk of HIV infection who are predisposed to, or already have, bone or renal conditions. While the approval of F/TAF is the first step in personalization of PrEP, additional options are still warranted to help accommodate the wide spectrum of individuals at risk of HIV with different lifestyles, medical histories, preferences, and requirements.

Secondary prevention for hepatocellular carcinoma in patients with chronic hepatitis B: are all the nucleos(t)ide analogues the same?

Reducing the incidence of hepatocellular carcinoma (HCC) in patients with chronic hepatitis B (CHB) is the key ultimate goal set in essentially all treatment guidelines. There has been solid evidence supporting the relationship between serum hepatitis B virus (HBV) DNA level and risk of HCC. Antiviral treatment with oral nucleos(t)ide analogues (NAs) leads to sustained viral suppression and hence is often adopted as the secondary prevention for HCC in CHB patients. The first-generation NA, lamivudine, reduced the risk of HCC at 3 years compared to placebo; yet, its high emergence of antiviral resistance has made it no longer recommended in the international guidelines. Recent heated debate is about the two current first-line NAs-entecavir and tenofovir disoproxil fumarate (TDF)-Are they just as good to reduce HCC risk in CHB patients? A handful of cohort studies show two different kinds of observations-TDF is better than entecavir in lowering HCC risk, or these two NAs have led to similarly low risk of HCC. Tenofovir alafenamide (TAF), a modified version of TDF higher rate of ALT normalization, would be another potent nucleotide analogue is the treatment of choice for secondary prevention for HCC.

Tenofovir alafenamide and rifabutin co-administration does not lead to loss of HIV-1 suppression: A retrospective observational study

OBJECTIVES

Tenofovir alafenamide (TAF) is a preferred nucleotide reverse transcriptase inhibitor used in the treatment of HIV. Co-administration of TAF with rifabutin (RFB) is not recommended due to concerns that RFB decreases TAF gastrointestinal absorption. The objective of this study was to determine the efficacy of antiretroviral therapy regimens that include the co-administration of TAF and RFB.

METHODS

Persons with HIV (PWH) who received TAF-RFB co-administration for ≥1 month were identified retrospectively. The primary outcome was the maintenance of HIV viral load <200 copies/mL (cpm) for those already on HIV therapy at RFB initiation, or suppression of viral load to <200 cpm for those with unsuppressed HIV viral load prior to TAF-RFB co-administration.

RESULTS

Twenty-two PWH met the inclusion criteria. Four out of five patients (80%) maintained a viral load <200 cpm and 15/17 (88%) achieved a viral load <200 cpm during TAF-RFB co-administration. After the exclusion of patients who self-discontinued therapy or were lost to follow-up, 19/19 (100%) met the combined primary endpoint of HIV viral load <200 cpm.

CONCLUSIONS

This study suggests that TAF-RFB co-administration may be effective despite concerns that RFB could reduce TAF absorption.

Tenofovir alafenamide does not inhibit mitochondrial function and cholesterol biosynthesis in human T lymphoblastoid cell line

In clinical trials, the concentration of tenofovir diphosphate (TFV-DP) in peripheral mononuclear cells was 4 to 5-fold higher in individuals treated with tenofovir alafenamide (TAF) compared to individuals treated with tenofovir disoproxil fumarate (TDF). We hypothesized that the higher intracellular accumulation of TFV-DP could cause mitochondrial toxicity from either polymerase gamma (Pol-γ)-dependent or Pol-γ-independent mechanism(s). To test this hypothesis, we cultured human T lymphoblastoid cell line (CEM cells) for up to 12 days with TAF or TDF (multiplicities of C_max) to investigate the effects on mitochondrial function and respiration, and cholesterol biosynthesis. Both TAF and TDF treatments had no significant effect on cell growth, mitochondrial potential (ΔΨ), production of reactive oxygen species (ROS), and mitochondrial respiratory parameters. TAF had no statistically significant effect on expression of Pol-γ mRNA, mitochondria DNA (mtDNA) content, expression of proteins of the electron transport chain (ETC), and key genes of cholesterol biosynthesis. TDF had significant reduction in mtDNA content at 8xC_max, and statistically significant reduction in mRNA expression of squalene epoxidase (SQLE). Our findings do not support our hypothesis that the higher intracellular accumulation of TFV-DP in cells treated with TAF could cause mitochondrial dysfunction. In conclusion, our findings add to the emerging data that TAF may have a low potential for causing mitochondrial toxicity in HIV-infected individuals on TAF-containing regimens.

Switching from tenofovir disoproxil fumarate to tenofovir alafenamide or dual therapy-based regimens in HIV-infected individuals with viral load ≤50 copies/mL: does estimated glomerular filtration rate matter?

Our aim was to evaluate the association between recent eGFR values and risk of switching from TDF to TAF or dual therapy (DT) in real life. HIV-positive patients achieving HIV-RNA ≤50 copies/mL for the first time after starting a TDF-based regimen were included. Kaplan-Meier (KM) curves and Cox regression models were used to estimate the time from TDF to switch to TAF or DT. 1486 participants were included: median (IQR) age 36 (30-42) years; baseline CKD-EPI eGFR 99.92 (86.47-111.4) mL/min/1.73m². We observed a consistently higher proportion of people with HIV-RNA ≤50 copies/mL who switched from TDF to TAF rather than to DT. By competing risk analysis, at 2 years from baseline, the probability of switching was 3.5% (95% CI 2.6-4.7%) to DT and 46.7% (42.8-48.5%) to TAF. A significantly higher probability of switching to TAF was found for patients receiving INSTI at baseline versus NNRTIs and PI/b [KM, 65.6% (61.7-69.4%) vs. 4.0% (1.8-6.1%) and 59.9% (52.7-67.2%), respectively; P < 0.0001]. eGFR <60 mL/min/1.73m² both as time-fixed covariate at baseline or as current value was associated with a higher risk of switching to DT [aHR 6.68 (2.69-16.60) and 8.18 (3.54-18.90); P < 0.001] but not to TAF-based cART [aHR 0.94 (0.39-2.31), P = 0.897; and 1.19 (0.60-2.38), P = 0.617]. Counter to our original hypothesis, current eGFR is used by clinicians to guide switches to DT but does not appear to be a key determinant for switching to TAF.