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.

Effect of tenofovir containing ART on renal function in patients with moderate/severe reduced creatinine clearance at baseline: A retrospective study at two referral hospitals in Namibia

Prescription of tenofovir disoproxil fumarate (TDF) for patients with baseline creatinine clearances (CrCl) <60 mL/min is said to increase risk of further decline in CrCl. Study objectives were to assess incidence of improvement and predictors thereof; to assess incidence of decline and transition to lower stages of CrCl; and comparison of declines between patients with a baseline CrCl < 60mL/min (group-I) and ≥ 60 mL/min (group-II). The study was retrospective, included patients 16 yrs or older who received TDF-containing ART. Improvement and decline were defined as ≥ 25% increase or decrease in CrCl, respectively. Binary logistic regression was performed to identify predictors of improvement. Groups I and II had 2862 and 7526 patients, respectively. In group-I, improvement in CrCl was observed in 40.1% (n = 1146), and was associated with stage IV of CrCl (adjusted Odds Ratio [aOR]=13.4 [95% CI: 6.7 - 26.9, P < .001]); male gender (aHR = 1.8 [95% CI: 1.5 - 2.2, P < .001]); and a poor HIV-status (aHR = 1.2 [95% CI: 1.0 - 1.4], P = .033). In group-I and group-II, respectively, decline occurred in 2.3% and 13.0%, (P < .001); transition to lower stages occurred in 1.0% and 25.2% (P < .001); and migration to stage IV CrCl occurred in 1.0% and 0.5% (P < .001). Improvement was more likely than decline in group-I patients. Although, group-I patients were more likely to experience new onset severe reduced CrCl than group-II patients, the proportions were extremely low. TDF should not be withheld from HIV-positive patients with a baseline CrCl < 60 mL/min.

Lipid Changes After Switch From TDF to TAF in the OPERA Cohort: LDL Cholesterol and Triglycerides

Background

Increases in lipids have been observed in people with HIV (PWH) switching from tenofovir disoproxil fumarate (TDF) to tenofovir alafenamide (TAF). We assessed changes in low-density lipoprotein cholesterol (LDL-C) and triglycerides (TG) following a switch from TDF to TAF.

Methods

Adults with ≥1 lipid measure before and after switch from TDF to TAF were identified in the OPERA cohort. Multivariable linear regression using generalized estimating equations was used to estimate predicted changes in lipids over time on TAF, modeled flexibly with linear splines.

Results

A total of 6451 PWH switched from TDF to TAF, of whom 4328 maintained all other agents. LDL-C increased significantly by 1.40 mg/dL/mo over the first 3 months on TAF, by 0.33 mg/dL/mo between 3 and 9 months and then plateauing beyond 9 months. TG increased significantly by 3.52 mg/dL/mo over the first 3 months of TAF, by 0.91 mg/mL/mo between 3 and 9 months and by 0.72 mg/mL/mo between 9 and 16 months, but decreased thereafter. Similar patterns were observed in analyses restricted to PWH who switched from TDF to TAF but maintained all other agents.

Conclusions

TDF-to-TAF switch was associated with LDL-C and TG increases over the first 9 to 16 months on TAF. The dynamic patterns observed cannot be attributed to changes in other agents.

Weight gain before and after switch from TDF to TAF in a U.S. cohort study

Introduction

Although weight gain has been reported with the use of integrase strand transfer inhibitors (InSTI), concurrent use of tenofovir alafenamide (TAF) has been implicated in recent studies. This study examined weight changes in people living with HIV (PLWH) who switched from tenofovir disoproxil fumarate (TDF) to TAF, to clarify the relative contribution to weight gain of core agents versus TDF to TAF switch.

Methods

Antiretroviral‐experienced, virologically suppressed PLWH in the U.S. OPERA cohort were included if they switched from TDF to TAF (5NOV2015‐28FEB2019) and either maintained all other antiretrovirals or switched from a non‐InSTI to an InSTI. Linear mixed models were used to assess weight changes before/after the switch to TAF (restricted cubic splines on time) and rates of change over time (linear splines on time, based on the shape of the weight change curves). Changes in weight on TDF or TAF were assessed among those who maintained other antiretrovirals (overall, by core class), and those who maintained an InSTI or switched to an InSTI (by core agent). All models were adjusted for age, sex, race, (age‐sex, race‐sex interactions), BMI, CD4 cell count, endocrine disorders and concurrent medications that could affect weight.

Results

A total of 6908 PLWH were included, with 5479 maintaining all other antiretrovirals (boosted protease inhibitor: 746, non‐nucleoside reverse transcriptase inhibitor: 1452, InSTI: 3281) and 1429 switching from a non‐InSTI to an InSTI (elvitegravir/cobicistat: 1120, dolutegravir: 174, bictegravir: 129). In adjusted models, modest weight gain was observed over time on TDF for most (0.24 to 0.71 kg/year); raltegravir was the exception with weight loss. Switching to TAF was associated with early, pronounced weight gain for all (1.80 to 4.47 kg/year). This effect with TAF switch was observed both in PLWH maintaining other antiretrovirals and those switching to an InSTI, regardless of which InSTI agent was used. Weight gain tended to slow down or plateau approximately nine months after switch to TAF.

Conclusions

In this large, diverse U.S. cohort of PLWH, switching from TDF to TAF was associated with pronounced weight gain immediately after switch, regardless of the core class or core agent, suggesting an independent effect of TAF on weight gain.

Factors associated to modification of first-line antiretroviral therapy due to adverse events in people living with HIV/AIDS

Antiretroviral therapy (ART) has modified the outcome of patients with HIV infection, providing virological control and reducing mortality. However, there are several reasons as to why patients may discontinue their antiretroviral therapy, with adverse events being one of the main reasons reported in the literature. This is a case-control nested in a cohort of people living with HIV/AIDS, conducted to identify the incidence of ART modification due to adverse events and the associated factors, in two referral services in Recife, Brazil, between 2011 and 2014. Of the modifications occurred in the first year of ART, 25.7% were driven by adverse events. The median time elapsed between initiating ART and the first modification due to adverse events was 70.5 days (95% CI: 26-161 days). The main adverse events were dermatological, neuropsychiatric and gastrointestinal. Dermatological events were the earliest to appear after initiating ART. Efavirenz was the most prescribed and most modified drug during the study period. The group of participants who used zidovudine, lamivudine, and efavirenz had a 2-fold greater chance (adjusted OR: 2.16 95% CI: 1.28-3.65) of switching ART due to adverse events when compared to the group that used tenofovir with lamivudine and efavirenz.

Brief Report: Tenofovir-Associated Nephrotoxicity Among a US National Historical Cohort of HIV-Infected Veterans: Risk Modification by Concomitant Antiretrovirals

BACKGROUND

Tenofovir disoproxil fumarate (TDF) has been associated with renal complications. The third agent in TDF-containing antiretroviral regimens may modify that risk. We compared renal adverse outcomes among treatment-naive HIV-infected patients initiating TDF-containing regimens including efavirenz (EFV) or other agents.

SETTING

This population-based historical cohort study used national Veterans Health Administration (VHA) clinical and administrative data sets to identify treatment-naive HIV-infected veterans initiating antiretroviral therapy with TDF/emtricitabine (FTC) + EFV, rilpivirine (RPV), elvitegravir/cobicistat (EVG/c), or ritonavir (RTV)-boosted protease inhibitors (PIs) from 2003 to 2015.

METHODS

Unadjusted incidence rates (IRs) for each regimen and covariate-adjusted hazard ratios [ using Cox proportional hazards models and inverse probability of treatment weighting] for between-regimen comparisons were calculated for renal outcomes including confirmed proteinuria, defined as 2 consecutive protein-to-creatinine ratios >150 mg/g or albumin-to-creatinine ratios >30 mg/g occurring ≥90 days apart; chronic kidney disease (CKD), defined as 2 consecutive estimated glomerular filtration rate measurements <60 mL·min·1.73 m occurring ≥90 days apart; and kidney dialysis.

RESULTS

Of 33,048 HIV-positive veterans, 4172 received EFV + TDF/FTC, 234 EVG/c/TDF/FTC, 173 RPV/TDF/FTC, and 2651 RTV-boosted PIs + TDF/FTC. Confirmed proteinuria and CKD IRs were numerically lower with EFV + TDF/FTC versus non-EFV + TDF/FTC (dialysis IRs were rare and comparable). After inverse probability of treatment weighting adjustment, EFV + TDF/FTC was associated with lower CKD risk versus non-EFV + TDF/FTC (hazard ratio, 0.62; 95% confidence interval, 0.53 to 0.72), EVG/c/TDF/FTC (0.75; 0.59 to 0.95), RPV/TDF/FTC (0.20; 0.17 to 0.24), and RTV-boosted PIs + TDF/FTC (0.62; 0.53 to 0.72).

CONCLUSIONS

EFV + TDF/FTC was associated with significantly lower risk of CKD versus other TDF-containing regimens in the Veterans Health Administration.

Taiwan consensus statement on the management of chronic hepatitis B

The experts of Taiwan Association for the Study of Liver (TASL) have actively participated and led the guidelines on hepatitis B virus (HBV) management by Asian Pacific Association for the Study of Liver (APASL) which is the first international association for the study of liver to publish the statement on HBV management before. However, there are more and more new data on the natural history and treatment of HBV infection in the past decade. These include new application of an old biomarker (quantitative HBsAg), clinical significance of HBV genotype and naturally occurring mutations, the role of non-invasive examination in evaluating severity of hepatic fibrosis, clinical significance of outcome calculators, new drug or new combination strategies towards more effective therapy and organ transplantation including liver and non-liver transplantation. It is time to publish the guidelines on HBV management of Taiwan. Hence, TASL have conducted an expert meeting to review, to discuss and to debate the relevant literatures, followed by draft the manuscript of HBV management guidelines and recommendations. The guidelines include general management, indications for fibrosis assessment, time to start or stop drug therapy, choice of drug to initiate therapy, when and how to monitor the patients during and after stopping drug therapy. Recommendations on the therapy of patients in special circumstances, including women in childbearing age, patients with antiviral drug resistance, concurrent viral infection, hepatic decompensation, patient receiving immune suppression or chemotherapy and patients in the setting of liver transplantation and hepatocellular carcinoma, are also included.

Incidence of Acute Kidney Injury in Patients Coinfected with HIV and Hepatitis C Virus Receiving Tenofovir Disoproxil Fumarate and Ledipasvir/Sofosbuvir in a Real-World, Urban, Ryan White Clinic

Ledipasvir/sofosbuvir (LDV/SOF), an antiviral treatment for hepatitis C virus (HCV), and tenofovir disoproxil fumarate (TDF), an antiretroviral for treating human immunodeficiency virus (HIV), may be coadministered in patients coinfected with these viruses. A drug interaction between LDV and TDF could increase TDF-associated nephrotoxicity rates; however, there is minimal clinical evidence describing acute kidney injury (AKI) rates in this population. This study was conducted at a Ryan White-funded facility in Atlanta, Georgia, that cares for over 5,000 patients with AIDS. This retrospective cohort used chart review to assess occurrence of and risk factors for AKI in HIV/HCV-coinfected patients receiving LDV/SOF and antiretroviral therapy (ART). AKI rates were compared between TDF-containing and non-TDF-containing ART groups according to Kidney Disease Improving Global Outcomes (KDIGO) criteria. Additional evaluated risk factors for AKI included chronic kidney disease and use of boosted protease inhibitor-based ART. In the 117 included patients, the overall incidence of AKI was 27.3%. AKI occurred more frequently in the non-TDF group (13/86, 15.1% vs. 19/31, 61.3%, p < .001). All AKI was KDIGO stage 1. From multivariable logistic regression, the only independent predictor of AKI was treatment with non-TDF relative to TDF (adjusted odds ratio 6.51, 95% confidence interval 2.34-18.10, p < .001). In this real-world cohort of HIV/HCV-coinfected patients, KDIGO-defined AKI was common, but occurred less frequently in patients receiving TDF-based ART. Our study suggests that patients with normal baseline renal function can be safely treated with TDF and LDV/SOF without significant nephrotoxicity if renal function is closely monitored.

The Acceptability of Pre-Exposure Prophylaxis: Beliefs of Health-Care Professionals Working in Sexually Transmitted Infections Clinics and HIV Treatment Centers

Background

Pre-exposure prophylaxis (PrEP) is highly effective for preventing HIV infections, but is not yet implemented in the Netherlands. As the attitudes of health-care professionals toward PrEP can influence future PrEP implementation, we studied PrEP knowledge and beliefs and their association with PrEP acceptability among professionals in clinics for sexually transmitted infection (STI professionals) and HIV treatment centers (HIV specialists). In addition, we examined preferred regimens, attitudes toward providing PrEP to key populations and to reimbursement of PrEP costs.

Methods

An online questionnaire was distributed among 24 public health STI clinics and 27 HIV treatment centers nationwide in the Netherlands between January and August 2015. The acceptability of PrEP was measured on a 7-point Likert scale ranging from 1 = low to 7 = high acceptability. Univariable and multivariable linear regression analyses were used to explore associations between demographic characteristics, PrEP knowledge, beliefs about PrEP, and PrEP acceptability.

Results

In total, 209 people (143 STI professionals and 66 HIV specialists) completed the questionnaire. The mean acceptability of PrEP implementation was 4.28 (SD 1.68) among STI professionals and 4.42 (SD 1.67) among HIV specialists. The mean score on self-perceived knowledge related to PrEP efficacy was 3.90 (SD 1.57) among STI professionals and 5.68 (SD 1.08) among HIV specialists (p-value of <0.001). Beliefs associated with lower PrEP acceptability among both groups were the fear that PrEP use will lead to a decrease in condom use and an increase in STI, the high costs of PrEP and ethical issues regarding prescribing antiretroviral medication to healthy individuals. No preference for a daily or an event-driven regimen was detected. Most participants deemed the following groups to be eligible for PrEP: men who have sex with men (MSM) who regularly get post-exposure prophylaxis, MSM who never used condoms with casual partners and MSM with an HIV-positive partner with a detectable viral load. Over half of the participants indicated that PrEP users should partly (54.1%) or fully (35.4%) pay the costs of PrEP.

Conclusion

In 2015, PrEP acceptability was only moderate among Dutch STI professionals and HIV specialists, which is far from an optimal setting. Addressing barriers to PrEP acceptability in educational programs for various types of health-care professionals is needed to successfully implement PrEP in the Netherlands.

Candidates for inclusion in a universal antiretroviral regimen: tenofovir alafenamide

PURPOSE OF REVIEW

Tenofovir disoproxil fumarate (TDF) is a standard first-line therapy for HIV. Recently, tenofovir alafenamide (TAF), a different prodrug for the same active moiety, has been approved. In this review, we have conducted a meta-analysis comparing efficacy and safety data for TDF and TAF, to inform a discussion of which drug would be best for a proposed 'universal antiretroviral (ARV) regimen'.

RECENT FINDINGS

We identified 10 randomized controlled trials comparing TDF with TAF (6969 patients, 8043 patient-years of follow-up). Meta-analysis found no difference in treatment efficacy, resistance, or adverse events. There were significant differences favouring TAF in bone mineral density measures and renal function measures, but no significant difference in bone fracture events or discontinuations because of bone toxicity or renal toxicity. TAF arms showed higher lipid levels, and were associated with a slightly greater risk of being started on lipid-lowering therapy.

SUMMARY

TAF has lesser detrimental effects on renal and bone markers, but no difference in adverse events. Data are unavailable for TAF safety in pregnancy, tuberculosis coinfection, and low CD4 count. Data for these groups, and an affordable price, will be required before it can be recommended as part of a 'universal ARV regimen'.

Safety of Tenofovir Disoproxil Fumarate-Based Antiretroviral Therapy Regimens in Pregnancy for HIV-Infected Women and Their Infants: A Systematic Review and Meta-Analysis

Supplemental Digital Content is Available in the Text.

Background:

There are limited data on adverse effects of tenofovir disoproxil fumarate (TDF)-based antiretroviral therapy (ART) on pregnant women and their infants.

Methods:

We conducted a systematic review of studies published between January 1980 and January 2017 that compared adverse outcomes in HIV-infected women receiving TDF- vs. non–TDF-based ART during pregnancy. The risk ratio (RR) for associations was pooled using a fixed-effects model.

Results:

Seventeen studies met the study inclusion criteria. We found that the rate of preterm (<37 weeks gestation) delivery (RR = 0.90, 95% confidence interval [CI]: 0.81 to 0.99, I² = 59%) and stillbirth (RR = 0.60, 95% CI: 0.43 to 0.84, I² = 72.0%) were significantly lower in women exposed (vs. not) to TDF-based ART regimen. We found no increased risk in maternal severe (grade 3) or potentially life-threatening (grade 4) adverse events (RR = 0.62; 95% CI: 0.30 to 1.29), miscarriage (RR = 1.09; 95% CI: 0.80 to 1.48), very preterm (<34 weeks gestation) delivery (RR = 1.08, 95% CI: 0.72 to 1.62), small for gestational age (RR = 0.87, 95% CI: 0.67 to 1.13), low birth weight (RR = 0.91; 95% CI: 0.80 to 1.04), very low birth weight (RR = 3.18; 95% CI: 0.65 to 15.63), congenital anomalies (RR = 1.03; 95% CI: 0.83 to 1.28), infant adverse outcomes or infant mortality (age >14 days) (RR = 0.65; 95% CI: 0.23 to 1.85), but increased neonatal mortality (age <14 days) risk (RR = 5.64, 95% CI: 1.70 to 18.79) with TDR-based ART exposure. No differences were found for anthropomorphic parameters at birth; one study reported minor differences in z-scores for length and head circumference at age 1 year.

Conclusions:

TDF-based ART in pregnancy seems generally safe for women and their infants. However, data remain limited and further studies are needed, particularly to assess neonatal mortality and infant growth/bone effects.

Nephrotoxicity Associated with Concomitant Use of Ledipasvir-Sofosbuvir and Tenofovir in a Patient with Hepatitis C Virus and Human Immunodeficiency Virus Coinfection

Direct-acting antivirals (DAAs) have revolutionized the treatment of hepatitis C virus (HCV) infection, with superior efficacy and safety compared to interferon-based therapies. Despite these improvements, drug interactions with DAAs exist and may be clinically relevant in human immunodeficiency virus (HIV)-coinfected patients. We present a case of nephrotoxicity associated with concomitant use of tenofovir disoproxil fumarate (TDF) and ledipasvir-sofosbuvir (LDV-SOF). A 56-year-old woman with HIV infection who had been taking efavirenz/tenofovir/emtricitabine (EFV/TDF/FTC) for 6 years developed acute kidney injury 8 weeks after initiating LDV-SOF for the treatment of HCV infection. Her serum creatinine concentration peaked at 10 mg/dL, compared with her baseline concentration of 0.9-1 mg/dL. Kidney biopsy revealed acute tubular necrosis and acute interstitial nephritis. Both LDV-SOF and TDF were discontinued, and the patient's serum creatinine concentration decreased to 1.3 mg/dL over the following 6 weeks. We postulate that this adverse drug reaction may have been secondary to the known interaction between ledipasvir and TDF, which results in increased TDF exposure. Despite knowledge of this interaction, LDV-SOF is commonly prescribed in patients with HIV-HCV coinfection, as patients who received LDV-SOF- and TDF-containing regimens in trials have not demonstrated adverse clinical consequences related to this interaction. This case highlights the rare but potentially serious nephrotoxicity that can result from TDF toxicity and serves as a reminder to clinicians to implement close renal function monitoring in patients receiving both LDV-SOF and TDF. Clinicians prescribing LDV-SOF to HCV-HIV-coinfected patients receiving TDF should be cautious about use with concomitant nephrotoxic medications and monitor markers of tubular dysfunction, including urinary phosphorus excretion, and renal injury at baseline and week 4 of therapy. Tenofovir alafenamide and alternative DAAs may also have a role in the management of patients at high risk for renal adverse effects from TDF.

Association of tenofovir disoproxil fumarate with primary allograft survival in HIV-positive kidney transplant recipients

BACKGROUND

Tenofovir disoproxil fumarate (TDF) is an antiretroviral agent frequently used to treat human immunodeficiency virus (HIV). There are concerns regarding its potential to cause acute kidney injury, chronic kidney disease, and proximal tubulopathy. Although TDF can effectively suppress HIV after kidney transplantation, it is unknown whether use of TDF-based antiretroviral therapy (ART) after kidney transplantation adversely affects allograft survival.

METHODS

We examined 104 HIV+ kidney transplant (KT) recipients at our center between 2001 and 2014. We generated a propensity score for TDF treatment using recipient and donor characteristics. We then fit Cox proportional hazards models to investigate the association between TDF treatment and 3-year, death-censored primary allograft failure, adjusting for the propensity score and delayed graft function (DGF).

RESULTS

Of the 104 HIV+ KT candidates who underwent transplantation during the study period, 23 (22%) were maintained on TDF-based ART at the time of transplantation, and 81 (78%) were on non-TDF-based ART. Median age of the cohort was 48 years; 87% were male; 88% were black; and median CD4 count at transplantation was 450 cells/mm³ . Median kidney donor risk index was 1.2. At 3 years post transplantation, primary allograft failure occurred in 26% of patients on TDF-based ART and in 28% of patients on non-TDF-based ART (P=.5). TDF treatment was not associated with primary allograft failure at 3 years post transplant after adjusting for DGF and a propensity score for TDF use (hazard ratio 2.12, 95% confidence interval 0.41-10.9).

CONCLUSIONS

In a large single-center experience of HIV+ kidney transplantation, TDF use following kidney transplantation was not significantly associated with primary allograft failure. These results may help inform management for HIV+ KT recipients in need of TDF therapy for adequate viral suppression.

HIV in the dialysis population: Current issues and future directions

Antiretroviral therapy has significantly reduced mortality due to HIV infection, but the aging HIV-positive patient population now faces a growing burden of comorbidity. This review describes the changing epidemiology of chronic kidney disease and end-stage renal disease in this population, and highlights recent advances in antiretroviral therapy and kidney transplantation that directly impact the care of patients with HIV infection and end-stage renal disease.

The role of tenofovir alafenamide in future HIV management

HIV infection has become a chronic condition rather than an acute life-threatening disease in developed countries, thanks to consistent innovation and evolution of effective interventions. This has altered HIV management and created new challenges. People living with HIV (PLWHIV) are living longer and so encounter comorbidities linked not only with their disease, but also with ageing, lifestyle and chronic exposure to antiretroviral therapy (ART). Although longevity, viral suppression and the prevention of viral transmission remain key goals, more needs to be achieved to encompass the vision of attaining an optimum level of overall health. Treatment choices and management practices should ensure patients' long-term health with minimal comorbidity. Treatments that balance optimal efficacy with the potential for improved long-term safety are needed for all patients. In this review, we consider the evolution and development of tenofovir alafenamide (TAF), a novel prodrug of tenofovir which offers high antiviral efficacy at doses over ten times lower than that of tenofovir disoproxil fumarate (TDF). Emerging clinical data suggest that elvitegravir, cobicistat, emtricitabine and TAF (E/C/F/TAF) as a single-tablet regimen offers highly effective viral suppression in treatment-naïve and treatment-experienced patients with an improved renal and bone safety profile compared with TDF, this having been demonstrated in diverse groups including patients with existing renal impairment and adolescents. The profile of TAF identifies it as an agent with a promising role within future ART regimens that aim to deliver the vision of undetectable viral load, while requiring less monitoring and having a safety profile designed to minimize comorbid risks while supporting good long-term health.

Real-World Assessment of Renal and Bone Safety among Patients with HIV Infection Exposed to Tenofovir Disoproxil Fumarate-Containing Single-Tablet Regimens

Objectives

Tenofovir disoproxil fumarate (TDF)-containing antiretroviral regimens have been associated with an increased incidence of renal and bone adverse outcomes. Here, we estimated the real-world incidence of renal and bone adverse outcomes among patients with HIV infection receiving different TDF-containing single-tablet regimens (STRs).

Methods

This cohort study used US health insurance data spanning the years 2008–2014. We identified HIV-infected patients aged ≥18 years (all HIV patients) and those with ≥6 months of continuous enrollment prior to initiating efavirenz/emtricitabine/TDF (EFV/FTC/TDF), rilpivirine/FTC/TDF (RPV/FTC/TDF) or elvitegravir/cobicistat/FTC/TDF (EVG/COBI/FTC/TDF). Renal adverse outcomes were identified using renal International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnosis codes. Bone adverse outcomes were identified using ICD-9-CM diagnosis codes for fracture. Incidence rates (IRs) and associated 95% confidence intervals (CIs) were estimated assuming a Poisson distribution, and outcomes between STRs were compared using IR ratios (IRRs) and IR differences (IRDs).

Results

We identified 9876 and 10,383 eligible patients for the renal and fracture analyses, respectively. Observed IRs for renal adverse outcomes were 9.7, 10.5, 13.6, and 18.0 per 1000 person-years among those receiving EFV/FTC/TDF, RPV/FTC/TDF, or EVG/COBI/FTC/TDF, or all HIV patients, respectively. Corresponding values for IRs of fracture were 3.4, 3.6, 7.2, and 4.4 per 1000 person-years, respectively. Renal adverse outcomes with EFV/FTC/TDF were significantly less frequent than with EVG/COBI/FTC/TDF (IRD −3.96; 95% CI: −7.31, −1.06). No IRR differences were identified for the renal analysis. Fractures with EFV/FTC/TDF were significantly less frequent than with EVG/COBI/FTC/TDF (IRR 0.47; 95% CI: 0.27, 0.81 and IRD −3.85; 95% CI: −5.02, −2.78).

Conclusions

In this large real-world database, observed IRs for renal adverse outcomes with TDF-containing STRs were lower or similar to those for all HIV patients, with the lowest IRs observed among patients receiving EFV/FTC/TDF. Compared with all HIV patients, the observed IR for fracture was higher with EVG/COBI/FTC/TDF, comparable with RPV/FTC/TDF, and lower with EFV/FTC/TDF.

Systematic review of renal and bone safety of the antiretroviral regimen efavirenz, emtricitabine, and tenofovir disoproxil fumarate in patients with HIV infection

BACKGROUND

Tenofovir disoproxil fumarate (TDF) is a component of many combinations of antiretroviral treatment (ART) regimens. Although potent and generally well tolerated, TDF may cause renal and bone toxicity. The magnitude of off-target side effects is proposed to be related to tenofovir plasma concentrations, which are affected by food and drug-drug interactions with concomitant antiretrovirals.

OBJECTIVE

To perform a systematic literature review and qualitatively report on renal and bone safety outcomes associated with efavirenz (EFV), emtricitabine (FTC), and TDF (EFV+FTC+TDF) ART.

METHODS

Embase and PubMed databases were searched for randomized clinical trials and observational cohort studies reporting on HIV treatment with EFV+FTC+TDF. Relevant articles were hand-searched for renal (Grade 3-4 serum creatinine/estimated glomerular filtration rate elevations, renal adverse events [AEs], discontinuation due to renal AEs, and urinary biomarkers) and bone outcomes (bone mineral density [BMD] reductions, bone turnover markers, and fracture), and results compiled qualitatively.

RESULTS

Of 337 retrieved articles, 29 reporting renal and 11 reporting bone outcomes met the review criteria. EFV+FTC+TDF was associated with a low frequency of renal AEs and treatment discontinuations due to renal AEs. Renal AEs were more frequent when TDF was taken with protease inhibitor (PI)- or cobicistat-containing ART. EFV+FTC+TDF was associated with reduced BMD and increased bone turnover markers, but BMD reductions were less than with PI-containing ART. No treatment-related bone fractures were identified.

CONCLUSIONS

EFV+FTC+TDF appeared to have a more favorable renal safety profile than TDF administered with a PI or cobicistat. BMD decreased with EFV+FTC+TDF, but no treatment-related fractures were identified.

Integrase inhibitor versus protease inhibitor based regimen for HIV-1 infected women (WAVES): a randomised, controlled, double-blind, phase 3 study

BACKGROUND

Women are under-represented in HIV antiretroviral therapy (ART) studies. Guidelines for selection of ART as initial therapy in patients with HIV-1 infection do not contain sex-specific treatment. We aimed to assess the safety and efficacy of the single tablet integrase inhibitor regimen containing elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate compared with a boosted protease inhibitor regimen of ritonavir-boosted atazanavir with emtricitabine and tenofovir disoproxil fumarate.

METHODS

In this international, randomised, controlled, double-blind, phase 3 study (Women AntiretroViral Efficacy and Safety study [WAVES]), we recruited treatment-naive HIV-infected women with an estimated creatinine clearance of 70 mL/min or higher from 80 centres in 11 countries. Women were randomly assigned (1:1) to receive elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate (integrase inhibitor regimen) or ritonavir-boosted atazanavir with emtricitabine and tenofovir disoproxil fumarate (protease inhibitor based regimen); regimens were masked with matching placebos. Randomisation was done by a computer-generated allocation sequence (block size four) and was stratified by HIV-1 RNA viral load and race. Investigators, patients, study staff, and those assessing outcomes were masked to treatment group. All participants who received one dose of study drug were included in the primary efficacy and safety analyses. The main outcome was the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48 as defined by US Food and Drug Administration snapshot algorithm (prespecified non-inferiority margin of 12%). This study is registered with ClinicalTrials.gov, number NCT01705574.

FINDINGS

Between Nov 28, 2012, and March 12, 2014, 575 women were enrolled. 289 were randomly assigned to receive the integrase inhibitor regimen and 286 to receive the protease inhibitor based regimen. 252 (87%) women in the integrase inhibitor group had plasma HIV-1 RNA less than 50 copies per mL at week 48 compared with 231 (81%) women in the protease inhibitor group (adjusted difference 6·5%; 95% CI 0·4-12·6). No participant had virological failure with resistance in the integrase inhibitor group compared with three participants ([1%]; all Met184Val/Ile) in the protease inhibitor group. 19 women in the protease inhibitor group discontinued because of adverse events compared with five in the integrase inhibitor group.

INTERPRETATION

WAVES shows that clinical trials of ART regimens in global and diverse populations of treatment-naive women are possible. The findings support guidelines recommending integrase inhibitor based regimens in first-line antiretroviral therapy.

FUNDING

Gilead Sciences.

Tenofovir clearance is reduced in HIV-positive patients with subclinical tubular impairment

OBJECTIVE

To assess if tenofovir (TFV) clearance is associated with urinary retinal-binding protein (RBP) in HIV-positive patients with normal estimated filtration rate.

DESIGN

A cross-sectional diagnostic study.

METHODS

HIV-positive patients with estimated creatinine clearance above 60 ml/min, on tenofovir disoproxil fumarate (TDF)-containing combination since at least 6 months, taking TDF at night, and without significant comorbidities (diabetes, untreated hypertension, known renal malformations, recurrent nephrolithiasis) and nephrotoxic drugs were included. TFV plasma and urinary concentrations were measured 12 h after drug intake (C12). RBP was measured through enzyme immunoassay kit on spot urines and corrected per urinary creatinine (uRBP/uCr); normality ranges were below 130 μg/g (in patients aged <50 years) and below 172 μg/g (in patients aged ≥50 years).

RESULTS

Two hundred and eighty-nine patients were included (median age of 45.8 years, 71.6% male and 85.4% whites); patients were concomitantly treated with nonnucleoside reverse transcriptase inhibitors (155, 53.6%), protease inhibitors (118, 40.8%), or integrase inhibitors (16, 5.5%)-containing regimens. Estimated creatinine clearance was 89.4 ml/min (78.6-105.9). Urinary RBP (uRBP) and uRBP/uCr were 204.6 ng/ml (92-380) and 169.7 μg/g (85.8-318.3), respectively; abnormally high uRBP/uCr was observed in 157 patients (54.3%). A multivariate binary logistic regression confirmed that both ethnicity (P = 0.004, β 2.93, 95% confidence interval 1.41-6.10) and TFV urinary C12 less than 21 mg/ml (P = 0.006, β 2.04, 95% confidence interval 1.12-3.41) were significantly associated with abnormal uRBP/uCr.

CONCLUSION

HIV-positive TDF-treated patients showed a high prevalence of proximal tubular impairment: ethnicity (whites) and low urinary TFV concentrations were significantly associated with elevated uRBP. SDC VIDEO:: http://links.lww.com/QAD/A852.

C-5-Modified Tetrahydropyrano-Tetrahydofuran-Derived Protease Inhibitors (PIs) Exert Potent Inhibition of the Replication of HIV-1 Variants Highly Resistant to Various PIs, including Darunavir

We identified three nonpeptidic HIV-1 protease inhibitors (PIs), GRL-015, -085, and -097, containing tetrahydropyrano-tetrahydrofuran (Tp-THF) with a C-5 hydroxyl. The three compounds were potent against a wild-type laboratory HIV-1 strain (HIV-1(WT)), with 50% effective concentrations (EC50s) of 3.0 to 49 nM, and exhibited minimal cytotoxicity, with 50% cytotoxic concentrations (CC50) for GRL-015, -085, and -097 of 80, >100, and >100 μM, respectively. All the three compounds potently inhibited the replication of highly PI-resistant HIV-1 variants selected with each of the currently available PIs and recombinant clinical HIV-1 isolates obtained from patients harboring multidrug-resistant HIV-1 variants (HIVMDR). Importantly, darunavir (DRV) was >1,000 times less active against a highly DRV-resistant HIV-1 variant (HIV-1DRV(R) P51); the three compounds remained active against HIV-1DRV(R) P51 with only a 6.8- to 68-fold reduction. Moreover, the emergence of HIV-1 variants resistant to the three compounds was considerably delayed compared to the case of DRV. In particular, HIV-1 variants resistant to GRL-085 and -097 did not emerge even when two different highly DRV-resistant HIV-1 variants were used as a starting population. In the structural analyses, Tp-THF of GRL-015, -085, and -097 showed strong hydrogen bond interactions with the backbone atoms of active-site amino acid residues (Asp29 and Asp30) of HIV-1 protease. A strong hydrogen bonding formation between the hydroxyl moiety of Tp-THF and a carbonyl oxygen atom of Gly48 was newly identified. The present findings indicate that the three compounds warrant further study as possible therapeutic agents for treating individuals harboring wild-type HIV and/or HIVMDR.

IMPORTANCE

Darunavir (DRV) inhibits the replication of most existing multidrug-resistant HIV-1 strains and has a high genetic barrier. However, the emergence of highly DRV-resistant HIV-1 strains (HIVDRV(R) ) has recently been observed in vivo and in vitro. Here, we identified three novel HIV-1 protease inhibitors (PIs) containing a tetrahydropyrano-tetrahydrofuran (Tp-THF) moiety with a C-5 hydroxyl (GRL-015, -085, and -097) which potently suppress the replication of HIVDRV(R) . Moreover, the emergence of HIV-1 strains resistant to the three compounds was considerably delayed compared to the case of DRV. The C-5 hydroxyl formed a strong hydrogen bonding interaction with the carbonyl oxygen atom of Gly48 of protease as examined in the structural analyses. Interestingly, a compound with Tp-THF lacking the hydroxyl moiety substantially decreased activity against HIVDRV(R) . The three novel compounds should be further developed as potential drugs for treating individuals harboring wild-type and multi-PI-resistant HIV variants as well as HIVDRV(R) .

Low Incidence of Renal Dysfunction among HIV-Infected Patients on a Tenofovir-Based First Line Antiretroviral Treatment Regimen in Myanmar

BACKGROUND

Since 2004, Médecins Sans Frontières-Switzerland has provided treatment and care for people living with HIV in Dawei, Myanmar. Renal function is routinely monitored in patients on tenofovir (TDF)-based antiretroviral treatment (ART), and this provides an opportunity to measure incidence and risk factors for renal dysfunction.

METHODS

We used routinely collected program data on all patients aged ≥15 years starting first-line TDF-based ART between January 2012 and December 2013. Creatinine clearance (CrCl) was assessed at base line and six-monthly, with renal dysfunction defined as CrCl < 50 ml/min/1.73 m2. We calculated incidence of renal dysfunction and used Cox regression analysis to identify associated risk factors.

RESULTS

There were 1391 patients, of whom 1372 had normal renal function at baseline. Of these, 86 (6.3%) developed renal dysfunction during a median time of follow-up 1.14 years with an incidence rate of 5.4 per 100 person-years: 78 had CrCl between 30-50 ml/min/1.73 m2 and were maintained on TDF-based ART, but 5 were changed to another regimen: 4 because of CrCl <30 ml/min/1.73 m2. Risk factors for renal dysfunction included age ≥45 years, diagnosed diabetes, underlying renal disease, underweight and CD4 count <200 cells/mm3. There were 19 patients with baseline renal dysfunction and all continued on TDF-based ART: CrCl stayed between 30-49 ml/min/1.73 m2 in five patients while the remainder regained normal renal function.

CONCLUSIONS

In a resource-poor country like Myanmar, the low incidence of renal toxicity in our patient cohort suggests that routine assessment of CrCl may not be needed and could be targeted to high risk groups if resources permit.