Tenofovir alafenamide vs. tenofovir disoproxil fumarate: an updated meta-analysis of 14 894 patients across 14 trials

Risk of hepatocellular carcinoma after curative treatment when switching from tenofovir disoproxil fumarate or entecavir to tenofovir alafenamide: A real-world multicenter cohort study

AIM

Antiviral treatment reduces the risk of developing hepatocellular carcinoma (HCC) in patients with chronic hepatitis B. However, there is a lack of high-quality evidence regarding the preventive effects of tenofovir alafenamide (TAF) on HCC. We evaluated the impact of TAF use after curative treatment on HCC recurrence.

METHODS

Patients who underwent surgery or radiofrequency ablation as a curative treatment for HCC were selected. Those patients who continued antiviral treatment with nucleos(t)ide analogs (NAs; entecavir [ETV] or tenofovir disoproxil fumarate [TDF]) or switched to TAF were included. The primary outcome was HCC recurrence, and the time-varying effect of NA use on HCC recurrence was analyzed using various statistical methods.

RESULTS

Among 2794 consecutive patients with chronic hepatitis B who received curative treatment for HCC, 199 subsequently switched from ETV or TDF to TAF. After a median of 3.0 years, 1303 patients (46.6%) experienced HCC recurrence. After propensity score matching (ratio 1:10), switching to TAF was not associated with an increased HCC recurrence (HR 1.00, 95% CI 0.68-1.47; p = 1.00) by time-varying Cox analysis. Switching to TAF was not associated with HCC recurrence in subgroups of NA (HR 1.06, 95% CI 0.67-1.67; p = 0.81 for TDF, and HR 1.09, 95% CI 0.51-2.33; p = 0.82 for ETV). Kaplan-Meier analysis showed comparable HCC recurrence-free survival between patients who switched to TAF and those who continued with their NA (p = 0.08). Time-varying Cox analyses in various subgroups confirmed the primary findings.

CONCLUSIONS

TAF is as effective as TDF and ETV in preventing HCC recurrence after curative treatment.

The changing landscape of HIV-associated kidney disease

The HIV epidemic has devastated millions of people globally, with approximately 40 million deaths since its start. The availability of antiretroviral therapy (ART) has transformed the prognosis of millions of individuals infected with HIV such that a diagnosis of HIV infection no longer automatically confers death. However, morbidity and mortality remain substantial among people living with HIV. HIV can directly infect the kidney to cause HIV-associated nephropathy (HIVAN) - a disease characterized by podocyte and tubular damage and associated with an increased risk of kidney failure. The reports of HIVAN occurring primarily in those of African ancestry led to the discovery of its association with APOL1 risk alleles. The advent of ART has led to a substantial decrease in the prevalence of HIVAN; however, reports have emerged of an increase in the prevalence of other kidney pathology, such as focal segmental glomerulosclerosis and pathological conditions associated with co-morbidities of ageing, such as hypertension and diabetes mellitus. Early initiation of ART also results in a longer cumulative exposure to medications, increasing the likelihood of nephrotoxicity. A substantial body of literature supports the use of kidney transplantation in people living with HIV, demonstrating significant survival benefits compared with that of people undergoing chronic dialysis, and similar long-term allograft and patient survival compared with that of HIV-negative kidney transplant recipients.

Discontinuation of tenofovir disoproxil fumarate from initial ART regimens because of renal adverse events: An analysis of data from four multi-country clinical trials

Tenofovir disoproxil fumarate (TDF), a potent and commonly used antiretroviral drug, is associated with renal tubular dysfunction and renal adverse events. We evaluated the frequency of, time to, and baseline risk factors for discontinuing TDF from initial antiretroviral therapy (ART) regimens because of renal adverse events from presumed tenofovir renal toxicity. We conducted an observational cohort study as a secondary analysis of data from four clinical trials conducted mainly in low- and middle-income countries. We included ART naïve participants living with HIV who started TDF-containing ART regimens in the trials. Participants had to have estimated creatinine clearance (eCrCl) equal to or greater than 60ml/min before starting ART. The primary outcome was the first instance of discontinuing TDF because of renal adverse events attributed to tenofovir renal toxicity during the first 48 weeks after starting ART. We evaluated the cumulative incidence of discontinuing TDF and associated risk factors using Fine and Gray competing risk regression models with a backward elimination variable selection strategy. There were 2802 ART-naïve participants who started TDF-containing ART from the four clinical trials were included in the analysis. Fifty-eight percent were female, the median age was 34 years, and 87% had CD4 cell counts less than 200 cells/μl. Sixty-four participants (2.4%, 95% CI 1.7%-2.8%) discontinued TDF due to renal adverse events. Among the 64 participants, the median time to discontinue TDF was 9.4 weeks (IQR: 3.4-20.7 weeks). From multivariable Fine and Gray regression models, risk factors for discontinuing TDF were older age, CD4 cell count <200 cells/μl, presence and severity of anemia, and eCrCl <90 ml/min. The risk of discontinuing TDF because of renal adverse events was low in participants initiating TDF-containing ART with advanced HIV and normal renal function, attesting to the tolerability of TDF in ART in low- and middle-income countries.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Tenofovir alafenamide plus dolutegravir as a switch strategy in HIV-infected patients: a pilot randomized controlled trial

BACKGROUND

Currently, two-drug antiretroviral regimens are emerging fields in life-long treatment in people living with HIV.

OBJECTIVES

This randomized non-inferiority open-label controlled trial was designed to compare the 48-week efficacy and safety of tenofovir alafenamide plus dolutegravir versus the standard triple therapy in virologically suppressed people living with HIV. To the best of our knowledge this combination has not been studied before.

METHODS

This open-label randomized controlled trial was conducted in treatment-experienced people with HIV who had HIV-RNA < 47 copies/mL for at least two years. Patients received either tenofovir alafenamide plus dolutegravir combination (26 patients) or a standard three-drug regimen (29 patients). The primary outcome was the proportion of patients maintaining HIV-RNA < 47 copies/mL during 48 weeks, and the secondary outcomes were CD4 cell count changes, the adherence rate, and adverse drug reactions, all over 48 weeks of study.

RESULTS

HIV viral load remained undetectable (HIV-RNA < 47 copies/mL) during the 48 weeks of the study in both arms. The absolute CD4 cell count change was not significant between the two groups. The overall proportion of adverse effects in each group was comparable. The rate of adherence to treatment was acceptable in both groups, and no significant difference was observed.

CONCLUSIONS

Treatment simplification with tenofovir alafenamide plus dolutegravir regimen as maintenance therapy was non-inferior in terms of efficacy and safety compared to the standard triple therapy. Comparing efficacy of antiretroviral therapy.

Comparing Safety and Effectiveness of Antiretroviral Therapy in a Diverse Population of Older People With HIV

Background Advances in antiretroviral therapy (ART) enable people with HIV to live longer, healthier lives. However, older people with HIV (OPWH) are more susceptible to long-term toxicity and drug interactions associated with ART. Racial and ethnic minorities have specific social determinants of health, which increase their risks of negative outcomes. Objective To determine if there were differences in the safety and effectiveness of ART in White, Black, and Hispanic OPWH. Methods A retrospective observational study was conducted on patients receiving care between January 1, 2017, and December 31, 2022, at two affiliated HIV clinics in South Florida. The primary effectiveness endpoint was the percentage of OPWH with undetectable viral load (< 50 copies/mL) throughout the study. Secondary safety endpoints were changes in median metabolic, hepatic, and renal parameters. A two-way analysis of variance or the Chi-square test was used to determine differences between groups. Results A total of 116 White, 42 Black, and 40 Hispanic OPWH were included. Upon enrollment, most patients (90.7%) were receiving ART. Of these, the percentage with undetectable viral load was lower among Black (61.8%) compared with White (85.8%; P < 0.01) or Hispanic (83.3%; P < 0.05) patients. Similarly, throughout the study after the first visit, the percentage with undetectable viral load was lower among Black (61.6%) compared with White (84.7%; P < 0.05) or Hispanic (83.3%; P = 0.12) patients. However, there were no significant differences in the percentage of virally suppressed (< 200 copies/mL) participants throughout the study after the first visit between Black (88.5%), White (94.9%), and Hispanic (96.7%) patients. Additionally, no significant changes in safety endpoints were observed among the groups throughout the study. Conclusion Fewer Black OPWH had undetectable viral load upon enrollment and throughout the study compared with White or Hispanic OPWH, suggesting the need to provide more targeted interventions for Black patients.

Tenofovir alafenamide versus entecavir for treating hepatitis B virus-related acute-on-chronic liver failure: real-world study

Background and aims

Real-world data regarding hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) patients receiving tenofovir alafenamide (TAF) as an antiviral drug are limited. Hence, we evaluated the efficacy and kidney safety of TAF among this population.

Methods

A total of 272 HBV-related ACLF patients hospitalized at Xiangya Hospital of Central South University were enrolled in this retrospective research. All patients received antiviral therapy with TAF (n = 100) or ETV (n = 172) and comprehensive medical treatments.

Results

Through 1:1 propensity score matching, 100 patients were finally included in each group. At week 48, the survival rates without transplantation of the TAF group and ETV group were 76.00 and 58.00%, separately (P = 0.007). After 4 weeks of treatment, the TAF treatment group exhibited a significantly decline in HBV DNA viral load (P = 0.029). The mean estimated glomerular filtration rate was apparently improved in the TAF group compared with the ETV group (TAF 5.98 ± 14.46 vs. ETV 1.18 ± 18.07 ml/min/1.73 m²) (P < 0.05). There were 6 patients in TAF group and 21 patients in ETV group with chronic kidney disease (CKD) stage progression ≥ 1. By contrast, the ETV treatment group has a greater risk of renal function progression in CKD 1 stage patients (P < 0.05).

Conclusion

This real-world clinical study showed that TAF is more effective than ETV in reducing viral load and improving survival rate in HBV-ACLF patients and the risk of renal function decline is lower.

Clinical trial registration

https://ClinicalTrials.gov, identifier NCT05453448.

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.

Effectiveness and safety of tenofovir alafenamide in children and adolescents living with HIV: a systematic review

INTRODUCTION

Tenofovir alafenamide (TAF) is approved for paediatric use in fixed-dose combination tablets, but efficacy and safety data in children are limited. We conducted a systematic review on the efficacy/effectiveness and safety of TAF in infants, children and adolescents living with HIV.

METHODS

We searched MEDLINE, Embase, the Cochrane Library, clinical trial registries, reference lists and relevant conferences to identify literature published January 2009-March 2021. We included clinical trials and observational studies assessing the efficacy/effectiveness or safety of TAF through ≥6 months of treatment in participants aged 0-19 years.

RESULTS AND DISCUSSION

Overall 3626 abstracts and 371 full papers were screened. Four single-arm, innovator-funded trials (341 participants) and a pooled analysis of those trials were identified. All four trials included treatment-experienced and virally suppressed children or adolescents. One trial also included treatment-naïve adolescents with baseline viral load >1000 copies/ml. The risk of bias was rated as low in one study and unclear in the other three owing to missing data on study design (all conference presentations). At 48 weeks, 92% (46/50) of treatment-naïve participants were virally suppressed (one trial). Among treatment-experienced participants with viral load at 48 weeks, 214 of 224 participants were virally suppressed. Across the studies, one grade 3/4 adverse event was considered drug-related (intermediate uveitis). There were three discontinuations for adverse events (grade 2 anxiety and insomnia, grade 1 iridocyclitis [drug-related] and grade 1 pulmonary tuberculosis [unrelated to treatment]). One accidental death occurred across the four studies. In the pooled analysis of 223 participants, the median change in bone mineral density z-score (height- and age-adjusted) from baseline to 48 weeks was -0.12 (interquartile range [IQR] -0.46, 0.17) to 0.05 (IQR not reported) for spine, and -0.09 (IQR -0.33, 0.07) to 0.09 (IQR not reported) for total body less head. Weight-for-age z-scores increased by 0.25 from baseline to 48 weeks.

CONCLUSIONS

Four single-arm trials were identified in this systematic review, with initial evidence suggesting good viral suppression and no obvious safety concerns in children and adolescents on TAF-containing regimens over 24-48 weeks. However, further comparative and longer-term safety data are needed in children and adolescents, including on weight and metabolic changes.

A prospective cohort study of renal function and bone turnover in adults with hepatitis B virus (HBV)-HIV co-infection with high prevalence of tenofovir-based antiretroviral therapy use

OBJECTIVE

Tenofovir disoproxil fumarate (TDF) is a common component of antiretroviral therapy in hepatitis B virus (HBV)-HIV co-infected adults but few studies have evaluated worsening renal function and bone turnover, known effects of TDF.

METHODS

Adults from eight North American sites were enrolled in this cohort study. Research assessments were conducted at entry and every 24 weeks for ≤192 weeks. Bone markers were tested at baseline, week 96 and week 192 from stored serum. We evaluated changes in markers of renal function and bone turnover over time and potential contributing factors.

RESULTS

A total of 115 patients were prospectively followed; median age 49 years, 91% male and 52% non-Hispanic Black. Duration of HIV was 20.5 years. TDF use ranged from 80% to 92% throughout follow-up. Estimated glomerular filtration rate (eGFR) (ml/min/1.73m² ) decreased from 87.1 to 79.9 over 192 weeks (p < 0.001); however, the prevalence of eGFR <60 ml/min/1.73m² did not appear to differ over time (always <16%; p = 0.43). From baseline to week 192, procollagen type I N-terminal propeptide (P1NP) (146.7 to 130.5 ng/ml; p = 0.001), osteocalcin (14.4 to 10.2 ng/ml; p < 0.001) and C-terminal telopeptides of type I collagen (CTX-1) (373 to 273 pg/ml; p < 0.001) decreased. Younger age, male sex and overweight/obesity versus normal weight predicted a decrease in eGRF. Black race, healthy weight versus underweight, advanced fibrosis, undetectable HBV DNA, and lower parathyroid hormone level predicted worsening bone turnover.

CONCLUSION

In this HBV-HIV cohort with high prevalence of TDF use, several biomarkers of renal function and bone turnover indicated worsening status over approximately 4 years, highlighting the importance of clinical awareness in co-infected adults.

Comparison of the design and methodology of Phase 3 clinical trials of bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) and dolutegravir-based dual therapy (DTG) in HIV: a systematic review of the literature

INTRODUCTION

Current recommended antiretroviral regimens include a combination of two (dual; DT) or three (triple; TT) antiretroviral drugs. This study aims to determine whether the quality of evidence from clinical trials of dolutegravir (dolutegravir/lamivudine [DTG/3TC] or dolutegravir/rilpivirine [DTG/RPV]) is methodologically comparable to that of clinical trials conducted with bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF).

AREAS COVERED

A systematic review of the medical literature was carried out in PubMed without date or language restrictions, following the PRISMA guidelines. All aspects of the methodological design of phase 3 randomized clinical trials (RCTs) of DT and TT, evaluated by the European Medicines Agency (registration trials), were reviewed. The quality of clinical trials was assessed using the Jadad scale.

EXPERT OPINION

The search identified 5, 3 and 2 phase 3 RCTs with BIC/FTC/TAF, DTG/3TC and DTG/RPV, respectively, that met the inclusion criteria. The designs would not be comparable due to differences in pre-randomization losses, blinding, patient recruitment, as well as differences in methodological quality, with the average score of the RCTs conducted with BIC/FTC/TAF, DTG/3TC and DTG/RPV being 4.2 (high quality), 3.0 (medium quality) and 3.0 (medium quality), respectively. Due to methodological differences between the BIC/FTC/TAF, DTG/3TC and DTG/RPV RCTs, the results of these are not comparable.

Clinical Considerations in the Selection of Preexposure Prophylaxis for HIV Prevention in Canada

According to the Public Health Agency of Canada, approximately 62,050 people were living with HIV in Canada in 2018, and of those, 13% were undiagnosed. Currently, no single strategy provides complete protection or is universally effective across all demographic groups at risk for HIV. However, HIV preexposure prophylaxis (PrEP) is the newest HIV prevention strategy that shows promise. To date, two products have received an indication for PrEP by Health Canada: emtricitabine/tenofovir disoproxil fumarate (Truvada®; FTC/TDF) and emtricitabine/tenofovir alafenamide (Descovy®; FTC/TAF). Despite the high efficacy of these PrEP intervention methods, access to PrEP in Canada remains low. Identifying and addressing barriers to PrEP access, especially in high-risk groups, are necessary to reduce HIV transmission in Canada. While guidelines published by the Center for Disease Control and Prevention (CDC) include FTC/TAF information, the efficacy of FTC/TAF for PrEP has not yet been considered in Canada's clinical practice guidelines. Thus, the current paper reviews data regarding the use of FTC/TDF and FTC/TAF for PrEP, which may be useful for Canadian healthcare providers when counseling and implementing HIV prevention methods. The authors highlight these data in relation to various at-risk populations and review ongoing clinical trials investigating novel PrEP agents. Overall, FTC/TDF PrEP is effective for many populations, including men who have sex with men, transgender women, heterosexuals with partners living with HIV, and people who use drugs. While there is fewer data reported on the efficacy of FTC/TAF to date, recent clinical trials have demonstrated noninferiority of FTC/TAF in comparison to FTC/TDF. Notably, as studies have shown that FTC/TAF maintains renal function and bone mineral density to a greater extent than FTC/TDF, FTC/TAF may be a safer option for patients experiencing renal and/or bone dysfunction, for those at risk of renal and bone complications, and for those who develop FTC/TDF-related adverse events.

Effect of alcohol exposure on the efficacy and safety of tenofovir alafenamide fumarate, a major medicine against human immunodeficiency virus

Human immunodeficiency virus (HIV) continues to be a major health concern. AIDS-related deaths (acquired immunodeficiency syndrome) have decreased recently, but chronic liver disease is now a major cause of mortality among HIV patients. Widespread alcohol use is recognized to be a major contributing factor. Tenofovir alafenamide fumarate (TAF), one of the most used HIV drugs, requires hydrolysis followed by phosphorylation to produce tenofovir diphosphate, the ultimate anti-HIV metabolite. Carboxylesterase-1 (CES1), established to hydrolyze TAF, is known to catalyze transesterification in the presence of ethanol. The aim of the study was to test the hypothesis that metabolism-based interactions between TAF and ethanol negatively impact both efficacy and safety of TAF. To test this hypothesis, the metabolism of TAF was determined in human primary hepatocytes and with a large number of human liver samples (S9 fractions) in the presence or absence of ethanol. The metabolism was monitored by LC-MS/MS (liquid chromatography with tandem mass spectrometry) and the level of CES1 or CES2 was determined by Western blotting. Consistent with the hypothesis, TAF underwent transesterification in the presence of ethanol accompanied by decreased hydrolysis. The formation of tenofovir diphosphate (the therapeutically active metabolite) was significantly decreased. In addition, TAF but not its hydrolytic metabolite, was found to increase intracellular lipid retention, and the increase was enhanced by ethanol. These findings conclude that alcohol consumption, beyond commonly accepted poor adherence to HIV medications, directly impacts the efficacy and safety of TAF.

Editorial: does TAF have a better or worse safety profile than TDF, to treat hepatitis B?

This article is linked to Lim et al papers. To view these articles, visit https://doi.org/10.1111/apt.16788 and https://doi.org/10.1111/apt.16886

Editorial: does TAF have a better or worse safety profile than TDF, to treat hepatitis B? Authors' reply

This article is linked to Lim et al papers. To view these articles, visit https://doi.org/10.1111/apt.16788 and https://doi.org/10.1111/apt.16854

Osteopenia in a young man associated with the use of tenofovir disoproxil fumarate

Tenofovir disoproxil fumarate is a recommended first‐line therapy for patients with chronic hepatitis B, although the frequent Tenofovir disoproxil fumarate related adverse drug reactions are nephrotoxicity and bone toxicity. We described the case of a 21‐year‐old Han Chinese male patient with chronic hepatitis B with tenofovir disoproxil fumarate‐associated osteopenia. The patient presented osteopenia at the site of his femoral neck with bone mineral density 0.865g/cm² (Z = −1.9) in January 2020. Nine months after switching to TAF, bone mineral density at left femoral neck improved to 0.978g/cm² (Z = −1.0) in September 2020. Bone mineral density of this patients was normal in January 2021. This is the first report in very young man presenting tenofovir disoproxil fumarate‐associated osteopenia.

Tenofovir-induced renal and bone toxicity: report of two cases and literature review

Tenofovir Disoproxil Fumarate (TDF) is one of the drugs in the initial first-line antiretroviral regimen for the treatment of hepatitis B and HIV infections. Despite its effectiveness and few adverse effects, it is related to renal and bone toxicity. We described two cases of HIV-positive middle-aged women who had been using TDF for two and four years (cases 1 and 2, respectively) and were admitted to the emergency room. Case 1 presented with metabolic ileum and diffuse bone pain while case 2 presented with bilateral coxo-femoral pain after a fall from standing height. Both cases had similar laboratory tests: hyperchloremic metabolic acidosis, hypophosphatemia, hypokalemia, hypouricemia and elevated plasma creatinine. In urinary exams, there was evidence of renal loss of electrolytes, justifying the serum alterations, in addition to glucosuria and proteinuria. The bone pain investigation identified bone fractures and reduced bone mineral density, together with increased levels of parathyroid hormone, alkaline phosphatase and vitamin D deficiency. These two cases illustrate the spectrum of adverse renal and bone effects associated with TDF use. TDF was discontinued and treatment was focused on correcting the electrolyte disturbances and acidosis, in addition to controlling the bone disease through vitamin D and calcium supplementation. The renal changes found in both cases characterized the Fanconi’s syndrome, and occurred due to TDF toxicity to proximal tubule cells mitochondria. Bone toxicity occurred due to direct interference of TDF in bone homeostasis, in addition to vitamin D deficiency and phosphaturia resulting from tubulopathy. During the follow-up, both cases evolved with chronic kidney disease and in one of them, the Fanconi’s syndrome did not revert. We emphasize the need to monitor markers of bone metabolism and glomerular and tubular functions in patients using TDF.

Is tenofovir disoproxil fumarate associated with weight loss?

BACKGROUND

Recent clinical trials have shown weight gain associated with newer antiretrovirals. It is unclear how the nucleoside reverse transcriptase inhibitor backbone affects weight. Recent evidence suggests greater weight gain with tenofovir alafenamide (TAF) compared with tenofovir disoproxil fumarate (TDF). However, it is not fully understood whether TDF contributes to weight suppression.

METHODS

A systematic search of PubMed, Embase and clinicaltrials.gov was conducted to identify all randomized control trials comparing TDF/FTC or TDF to control in HIV-negative individuals. The primary endpoint included the number of events of 5% weight loss. Mantel-Haenszel test with random-effects modelling was used to calculate the odds ratio (OR) and 95% confidence intervals (95% CI). Further analyses of gastrointestinal (GI) adverse events were also undertaken.

RESULTS

Seven PrEP trials: PARTNERS, VOICE, TDF-2, Bangkok PrEP, iPrEX, FEM-PrEP and HPTN 084 were included in the analysis of weight loss, with a total sample size of 19 359. One study (HPTN 084) compared TDF/FTC to cabotegravir (CAB). HIV-negative individuals taking TDF were more likely to experience weight loss compared with control [odds ratio (OR) 1.44; 95% CI 1.12-1.85; P = 0.005). Exposure to TDF was also linked to greater odds of vomiting (OR 1.81; 95% CI 1.20-2.73; P < 0.005). There were no increased odds of nausea, diarrhoea or loss of appetite.

CONCLUSION

There is evidence in HIV-negative individuals that TDF may be associated with weight loss. Further research should be carried out in HIV-positive individuals, and clinical trials of TDF/FTC should publish weight data to widen the evidence base.

Switch from Tenofovir Disoproxil Fumarate to Tenofovir Alafenamide in People Living with HIV: Lipid Changes and Statin Underutilization

BACKGROUND AND OBJECTIVE

Many people living with HIV (PLWH) on stable tenofovir disoproxil fumarate (TDF)-containing regimens have switched to tenofovir alafenamide (TAF), despite the potential lipid-lowering effect of TDF. We aimed to assess the impact of switching from TDF to TAF on lipids in real-world clinical practice.

METHODS

PLWH prescribed TDF for ≥ 4 weeks who switched to TAF were identified in the OPERA cohort. Patterns of dyslipidemia were compared before and after switch based on NCEP ATPIII guidelines. Elevated 10-year risk of atherosclerotic cardiovascular disease (ASCVD ≥ 7.5%) and statin use were assessed.

RESULTS

Among 6423 PLWH switched from TDF to TAF, the proportion with dyslipidemia/severe dyslipidemia observed after switch from TDF to TAF increased statistically significantly (p < 0.0001) with total cholesterol (5-10%), low-density lipoprotein cholesterol (16-23%), and triglycerides (21-27%), but decreased statistically significantly with high-density lipoprotein cholesterol (35-30%, p < 0.0001). These patterns of dyslipidemia persisted in sensitivity analyses restricted to PLWH who maintained all other antiretrovirals (N = 4328) or stratified by pharmaco-enhancer use before and after switch. An elevated ASCVD risk was detected in 29% before and 31% after switch. As many as 59% of PLWH with an elevated ASCVD risk were not prescribed a statin after switch from TDF to TAF.

CONCLUSIONS

In this large, diverse population of PLWH in the USA, the switch from TDF to TAF was associated with development of less favorable lipid profiles, regardless of pharmaco-enhancers or third-agent use. Statins remained underutilized after a switch from TDF to TAF.

Renal adverse drug reactions

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is common in people living with HIV (PLWH) and is related to a multitude of factors. The aim of this review is to provide an overview of the most recent evidence of renal adverse effects of antiretroviral drugs, predictors of CKD risk and areas for future research.

RECENT FINDINGS

Advancing age, cardiometabolic risk factors and adverse effects of antiretroviral drugs contribute to the higher prevalence of CKD in PLWH. Genetic factors and baseline clinical CKD risk are strongly correlated to risk of incident CKD, although it is unclear to what extent gene polymorphisms explain renal adverse effects related to tenofovir disoproxil fumarate (TDF). Switching from TDF to tenofovir alafenamide (TAF) in people with baseline renal dysfunction improves renal parameters; however, the long-term safety and benefit of TAF in individuals at low risk of CKD is an area of ongoing research.

SUMMARY

Several factors contribute to estimated glomerular function decline and CKD in PLWH. Clinical risk scores for CKD may be useful to inform selection of ART in an ageing population. In people with baseline renal dysfunction, potentially nephrotoxic antiretroviral drugs should be avoided.

ABCC4 single-nucleotide polymorphisms as markers of tenofovir disoproxil fumarate-induced kidney impairment

Recently, the use of antiretroviral drug tenofovir disoproxil fumarate (TDF) is increased, thanks to the new co-formulation with doravirine, the availability of booster-free regimens, and its advantageous lipid-lowering effect. The aim of our study was to identify genetic markers that contribute to assess the risk of TDF-related renal toxicity. We have retrospectively investigated, in 179 HIV positive patients treated with TDF, the association between the main variants in ABCC2, ABCC4, and ABCC10 genes and four safety endpoints, three clinically relevant as renal outcomes and a higher tenofovir plasma concentration. In patients with an annual eGFR decline >5 mL/min/1.73 m² a difference in genotype frequencies was observed for ABCC10 c.1875 + 526 G>A (3 subjects AA vs. 44 GG + GA, p = 0.045). In patients with an eGFR decrement >25%, plus a decline in GFR category and TDF discontinuation, a difference was observed for ABCC4 c.*38T>G (35 subjects TG + GG vs. 18 TT, p = 0.052). At univariate analysis OR was 1.39 [(95% CI 1.00-1.96) p = 0.054] and at multivariate analysis OR was 1.49 [(95% CI 1.00-2.22) p = 0.049]. The stronger associations were found between the tenofovir accumulation and ABCC4 c.*38T>G and c.3348G>A: the percentage of these patients was higher in the TG + GG (p = 0.011) and in the AA (p = 0.004) genotype, respectively. The logistic regression analysis confirmed these significant relationships. No significant association was observed in patients with eGFR < 60 mL/min/1.73m² and with the studied ABCC2 polymorphisms. Our results show a major role for a combined determination of ABCC4/ABCC10 variants as an indicator of tenofovir toxicity in the clinical practice.

Risks and benefits of reducing the number of drugs to treat HIV-1 infection

Introduction: Despite the efficacy and safety of antiretroviral therapy, new treatment options are needed to address the concerns of patients and physicians regarding long-term toxicities, costs, and convenience of lifelong antiretroviral therapy. To achieve this goal, one strategy is to reduce the number of drugs in the antiretroviral regimen.Areas covered: We review the recent evidence on the efficacy and safety of reduced drug regimens and their potential risks and benefits. There is currently strong evidence showing that some two-drug regimens have a comparable efficacy and short-term safety compared to standard three-drug regimens. The fixed-dose combination of dolutegravir/lamivudine is already an alternative for many treatment-naïve and virologically suppressed HIV-1 infected adults supported by large randomized clinical trials. The co-formulation dolutegravir plus rilpivirine is also a switch strategy for maintenance therapy. Long-acting injectable cabotegravir plus rilpivirine has already regulatory approval, and islatravir plus doravirine is an expected option in the near future. Some two-drug regimens have not been as successful.Expert opinion: Long-term safety issues of these two-drug regimens remain to be determined, but with the overwhelming evidence available in virological control and short-term safety, the potential benefits of some of these two-drug regimens appear to outweigh the risks.

Are New Antiretroviral Treatments Increasing the Risk of Weight Gain?

There is a growing body of evidence from both observational and randomised trials implicating integrase inhibitors, particularly dolutegravir and bictegravir, with the development of weight gain and obesity in people living with HIV. Evidence with cabotegravir, the newest integrase inhibitor, is limited. Reasons for weight gain are currently unknown. Proposed mechanisms include improved tolerability, direct impact on adipogenesis, and gut microbiome disturbance. Clinical trials have found that weight gain with integrase inhibitors is greatest for women and people of Black ethnicity. Evidence suggests that the nucleoside reverse transcriptase backbone has additional effects on weight gain, with tenofovir alafenamide potentially enhancing the weight gain effect. Weight gain and obesity have long-term consequences, including metabolic syndrome, development of type 2 diabetes mellitus, cardiovascular disease and adverse birth outcomes. However, the current evidence for the medium and long-term effects of weight gain associated with integrase inhibitors is limited. There is an urgent need for clinical trials with longer follow-up periods and standardised endpoints to evaluate these effects. New thresholds for weight gain should be established as guidance for clinicians to stop treatment where weight gain is excessive. Novel treatments such as doravirine could offer a suitable therapy alternative, with current evidence showing efficacy with limited effect on weight gain.