The renal-bone axis in older people living with HIV on stable antiretroviral therapy: A sub-analysis of the GS-US-104-0423 study.

BACKGROUND: Data on low bone mineral density (BMD) in people living with HIV (PLWH) are mainly derived from younger adults; little is known about how antiretroviral therapy (ART) and alterations in the renal-bone axis relate to BMD in older PLWH. METHODS: Cross-sectional study of men > 50 years and post-menopausal women with HIV. Antiretroviral therapy exposure was stratified into four groups based on use of tenofovir disoproxil fumarate (TDF) and protease inhibitors (PI): non-TDF/non-PI, non-TDF/PI, TDF/non-PI, and TDF/PI. Bone mineral density was measured by dual X-ray absorptiometry (DXA). Bone turnover/regulatory markers and renal tubular function were analysed in stored plasma and urine samples. The association of ART exposure and bone/renal biomarkers on BMD was explored using logistic regression models. RESULTS: 247 individuals (median [IQR] age 57 [53, 65] years; 47% female; 13% of Black ethnicity; CD4 count 643 [473, 811] cells/mm3; and 98% with HIV RNA < 200 copies/mL) were included. Bone turnover and renal tubular function differed significantly by ART exposure. In analyses adjusted for demographic and traditional renal/bone risk factors, exposure to TDF and PI was associated with a fourfold greater risk of low BMD at the femoral neck and exposure to TDF and/or PI with a threefold greater risk of low BMD at the lumbar spine. The relationship between ART and low BMD was not altered by further adjustment for bone turnover or renal tubular function markers. CONCLUSIONS: The associations between low BMD and ART exposure (TDF vs. non-TDF and boosted vs. unboosted third agents) were minimally affected by adjustments for bone and kidney biomarkers.

Fixed-dose combination bictegravir, emtricitabine, and tenofovir alafenamide in adolescents and children with HIV: week 48 results of a single-arm, open-label, multicentre, phase 2/3 trial.

BACKGROUND: Bictegravir is a potent integrase strand-transfer inhibitor (INSTI) with a high genetic barrier to resistance. Bictegravir, coformulated with emtricitabine and tenofovir alafenamide, is recommended by key European and US HIV treatment guidelines as the preferred single-tablet regimen for adults and adolescents. The aim of this study was to assess the pharmacokinetics, safety, and efficacy of switching to this regimen in virologically suppressed children and adolescents with HIV. METHODS: In this single-arm, open-label trial, we enrolled virologically suppressed children and adolescents (aged 6 to <18 years) with HIV at 22 hospital clinics in South Africa, Thailand, Uganda, and the USA. Eligible participants had a bodyweight of at least 25 kg, were virologically suppressed (HIV-1 RNA <50 copies per mL) on a stable ART regimen for at least 6 months before screening, had a CD4 count of at least 200 cells per µL, and an estimated glomerular filtration rate of at least 90 mL/min per 1·73 m2 by the Schwartz formula at screening. All participants received the fixed-dose regimen of coformulated bictegravir 50 mg, emtricitabine 200 mg, and tenofovir alafenamide 25 mg once daily. Pharmacokinetic analysis was used for dosing confirmation, and results compared with adult values. The primary outcomes were area under the curve at the end of the dosing interval (AUCtau) and concentration at the end of the dosing interval (Ctau) of bictegravir, and incidence of treatment-emergent adverse events and laboratory abnormalities at week 24. Efficacy and safety analyses included all participants who received at least one dose of study drug. We report the 48-week results. This study is registered with ClinicalTrials.gov, NCT02881320. FINDINGS: Between Sept 29, 2016 and Feb 16, 2018, we enrolled 102 participants. 100 participants received bictegravir, emtricitabine, and tenofovir alafenamide (cohort 1 [adolescents aged 12 to <18 years], n=50; cohort 2 [children aged 6 to <12 years], n=50). The mean bictegravir AUCtau was 89 100 ng × h/mL (coefficient of variation 31·0%) in adolescents (cohort 1) and 128 000 ng × h/mL (27·8%) in children (cohort 2). Compared with adults, bictegravir Ctau was 35% lower in adolescents and 11% lower in children. The 90% CIs of both parameters were within the predefined pharmacokinetic equivalence boundary and within overall range of exposures observed in adults and deemed to be safe and efficacious (geometric least-squares mean ratio [GLSM] 86·3% [90% CI 80·0-93·0] for AUCtau and 65·4% [58·3-73·3] for Ctau in adolescents; GLSM 125% [90% CI 117-134] for AUCtau and 88·9% [80·6-98·0] for Ctau for children). Bictegravir, emtricitabine, and tenofovir alafenamide was well tolerated; most adverse events were grade 2 or less in severity and no study drug-related serious adverse events were reported. One participant discontinued study drug due to adverse events (grade 2 insomnia and anxiety). Virological suppression (HIV-1 RNA <50 copies per mL) was maintained by all 100 participants at week 24 and by 98 (98%) of 100 at week 48; no participants had treatment-emergent resistance. INTERPRETATION: In adolescents and children with HIV, the bictegravir, emtricitabine, and tenofovir alafenamide single-tablet regimen was well tolerated and maintained virological suppression. Our data support the treatment of HIV in adolescents and children with this single-tablet regimen. At present, the single-tablet regimen is recommended as first-line treatment in the USA for adolescents and as an alternative regimen in children and has the potential to represent an important regimen in the paediatric population. FUNDING: Gilead Sciences.

Vesatolimod, a Toll-like Receptor 7 Agonist, Induces Immune Activation in Virally Suppressed Adults Living With Human Immunodeficiency Virus-1.

BACKGROUND: Treatment with vesatolimod, an investigational, oral, toll-like receptor 7 (TLR7) agonist, leads to sustained viral remission in some non-human primates when combined with anti-envelope antibodies or therapeutic vaccines. We report results of a Phase Ib study evaluating safety, pharmacokinetics, and pharmacodynamics of vesatolimod in adults living with human immunodeficiency virus (HIV)-1. METHODS: In this double-blind, multicenter, placebo-controlled trial, participants on antiretroviral therapy with screening plasma HIV-1 RNA levels <50 copies/mL were randomized (6:2) to receive 6-10 doses of vesatolimod (1-12 mg) or matching placebo orally every other week in sequential dose-escalation cohorts. The primary study objectives included establishing the safety and virologic effects of vesatolimod (change from baseline in plasma HIV-1 RNA). Pharmacokinetics and pharmacodynamic/immunologic activity were assessed as secondary objectives. RESULTS: A total of 48 individuals were randomly assigned to vesatolimod (n = 36) or placebo (n = 12). Vesatolimod was generally well tolerated, with no study drug-related serious adverse events or adverse events leading to study drug discontinuation. There were no statistically significant changes from baseline in plasma HIV-1 RNA in the vesatolimod groups, compared to placebo.Vesatolimod plasma exposures increased dose proportionally; consistent responses in cytokines, interferon-stimulated gene expression, and lymphocyte activation were observed with increasing dose levels above 4 mg. Peak elevations 24 hours after receipt of a 6 mg dose were >3.9-fold higher for interferon gamma-induced protein 10 (IP-10), interleukin-1 receptor antagonist (IL-1RA), interferon-inducible T-cell alpha chemoattractant (ITAC) when compared to baseline values. CONCLUSIONS: Vesatolimod was well tolerated at doses ranging from 1 to 12 mg. Immune stimulation was observed at doses above 4 mg, providing rationale for future combination trials in people living with HIV. CLINICAL TRIALS REGISTRATION: NCT02858401.

Switching to bictegravir/emtricitabine/tenofovir alafenamide maintained HIV-1 RNA suppression in participants with archived antiretroviral resistance including M184V/I.

OBJECTIVES: Studies 1878 and 1844 demonstrated non-inferior efficacy of switching suppressed HIV-1-infected adults to bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF) versus continuing boosted PI-based triple regimens or dolutegravir/abacavir/lamivudine (DTG/ABC/3TC). Here, detailed analyses of pre-existing resistance in the two BIC/FTC/TAF switch studies and efficacy at week 48 are described. METHODS: Pre-existing resistance was assessed from historical genotypes (documented resistance to study drugs was excluded) and by retrospective baseline proviral archive DNA genotyping from whole blood. Outcomes were based on HIV-1 RNA at week 48 with missing values imputed using the last on-treatment observation carried forward method. RESULTS: Cumulative pre-existing resistance data from historical and proviral genotypes were obtained for 95% (543/570) of participants who switched to BIC/FTC/TAF. Altogether, 40% (217/543) had one or more pre-existing primary resistance substitutions in protease, reverse transcriptase and/or integrase. Pre-switch NRTI resistance was detected in 16% (89/543) of BIC/FTC/TAF-treated participants, with M184V or M184I detected by proviral genotyping in 10% (54/543). At week 48, 98% (561/570) of all BIC/FTC/TAF-treated participants versus 98% (213/217) with pre-existing resistance and 96% (52/54) with archived M184V/I had HIV-1 RNA <50 copies/mL. No BIC/FTC/TAF-treated participants developed treatment-emergent resistance to study drugs. CONCLUSIONS: Pre-existing resistance substitutions, notably M184V/I, were unexpectedly common among suppressed participants who switched to BIC/FTC/TAF. High rates of virological suppression were maintained in the overall study population and in those with pre-existing resistance, including M184V/I, for up to 48 weeks of BIC/FTC/TAF treatment with no resistance development. These results indicate that BIC/FTC/TAF is an effective treatment option for suppressed patients, including those with evidence of archived NRTI resistance.

Efficacy and safety of switching to fixed-dose bictegravir, emtricitabine, and tenofovir alafenamide from boosted protease inhibitor-based regimens in virologically suppressed adults with HIV-1: 48 week results of a randomised, open-label, multicentre, phase 3, non-inferiority trial.

BACKGROUND: Switching from therapy based on a boosted protease inhibitor to bictegravir, emtricitabine, and tenofovir alafenamide could avoid drug interactions and unwanted side-effects in virologically suppressed adults with HIV-1 infection, while maintaining a high barrier to resistance and providing a simplified once-daily, single-tablet regimen. Here, we report 48 week results of a phase 3 study investigating this switch. METHODS: In this multicentre, randomised, open-label, active-controlled, non-inferiority, phase 3 trial, adults with HIV-1 infection were enrolled at 121 outpatient centres in ten countries. Eligible participants were aged 18 years or older, had an estimated glomerular filtration rate of 50 mL per min or higher, had been virologically suppressed (plasma HIV-1 RNA <50 copies per mL) for 6 months or more before screening, and were on a regimen consisting of boosted atazanavir or darunavir plus either emtricitabine and tenofovir disoproxil fumarate or abacavir and lamivudine. We randomly assigned participants (1:1), using a computer-generated randomisation sequence, to switch to co-formulated once-daily bictegravir (50 mg), emtricitabine (200 mg), and tenofovir alafenamide (25 mg), herein known as the bictegravir group, or to remain on their baseline boosted protease inhibitor regimen, herein known as the boosted protease inhibitor group, for 48 weeks. Randomisation was stratified by use of tenofovir disoproxil fumarate or abacavir at screening. The primary endpoint was the proportion of participants with plasma HIV-1 RNA of 50 copies per mL or higher at week 48 (by US Food and Drug Administration snapshot algorithm), with a prespecified non-inferiority margin of 4%. Efficacy and safety analyses included all participants who received at least one dose of study drug. This study is ongoing but not actively recruiting patients and is registered with ClinicalTrials.gov, number NCT02603107. FINDINGS: Between Dec 2, 2015, and July 15, 2016, 578 participants were randomly assigned and 577 were treated (290 in the bictegravir group and 287 in the boosted protease inhibitor group). At week 48, five participants (2%) in the bictegravir group and five (2%) in the boosted protease inhibitor group had plasma HIV-1 RNA of 50 copies per mL or higher (difference 0·0%, 95·002% CI -2·5 to 2·5), thus switching to the bictegravir regimen was non-inferior to continued boosted protease inhibitor therapy. The overall incidence and severity of adverse events was similar between groups, although headache occurred more frequently in the bictegravir group than in the boosted protease inhibitor group. 233 (80%) participants in the bictegravir group and 226 (79%) in the boosted protease inhibitor group had an adverse event. Only two (1%) participants in the bictegravir group and one (<1%) in the boosted protease inhibitor group discontinued treatment because of adverse events. 54 participants (19%) in the bictegravir group had drug-related adverse events compared with six (2%) in the protease inhibitor group. INTERPRETATION: Fixed-dose bictegravir, emtricitabine, and tenofovir alafenamide might be a safe and efficacious alternative to continued boosted protease inhibitor therapy in adults with HIV-1 infection. FUNDING: Gilead Sciences.

Elvitegravir/cobicistat/emtricitabine/tenofovir DF in HIV-infected patients with mild-to-moderate renal impairment.

In HIV-1-infected treatment-naive patients with mild-to-moderate renal impairment [creatinine clearance (CrCl): 50-89 mL/min], elvitegravir/cobicistat/emtricitabine/tenofovir DF (STB, n = 33) achieved high rates of virologic success (78.8%; 95% confidence interval: 61.1% to 91.0%) and was well tolerated through week 48. Four patients discontinued study drug due to an adverse event and none due to proximal renal tubulopathy. As expected, decreases in CrCl were noted as early as week 2, after which they stabilized. The renal safety profile of STB in patients from this study is consistent with the long-term experience in a large number of patients with CrCl ≥70 mL/min.

Cobicistat-boosted protease inhibitors in HIV-infected patients with mild to moderate renal impairment.

BACKGROUND: Cobicistat (COBI) is a pharmacoenhancer that optimizes systemic exposures of protease inhibitors (PIs) such as atazanavir (ATV) and darunavir (DRV). OBJECTIVE: To evaluate the efficacy and safety of switching ritonavir (RTV) to COBI in patients with creatinine clearance (CrCl) 50 to 89 mL/min who are virologically suppressed on a stable regimen containing ritonavir (RTV)-boosted ATV or DRV. Other components of the regimen remained unchanged. METHODS: A phase 3, non-comparative, open-label clinical trial. RESULTS: Seventy-three patients were enrolled. At week 48, 82% maintained virologic suppression. No emergent resistance developed. Serious adverse events (AEs) occurred in 7%, and study drug discontinuation due to AEs occurred in 10% (7 patients). There were 2 renal discontinuations and no cases of proximal renal tubulopathy. Small reductions in CrCl (median [IQR]) were observed as early as week 2, after which they were nonprogressive through week 48 (-3.8 [-9 to 0.8]). Changes in CrCl by baseline CrCl (< 70 vs ≥ 70) were -1.1 [-6.5 to 6.3] versus -6.6 [-12.4 to -0.7], respectively. CONCLUSIONS: In HIV-1-infected patients with CrCl 50 to 89 mL/min switching from RTV to COBI, COBI-boosted PIs in combination with 2 nucleos(t)ide reverse transcriptase inhibitors were well-tolerated and effective in maintaining virologic suppression. The renal safety profile of COBI in this study was consistent with the long-term data in patients without renal impairment from the phase 3 studies of COBI-containing regimens.

Switching from ritonavir to cobicistat in HIV patients with renal impairment who are virologically suppressed on a protease inhibitor.

INTRODUCTION: Cobicistat (COBI) is a pharmacoenhancer and one of the components of ECF/TDF (elvitegravir/cobicistat/emtricitabine/tenofovir DF), which is approved in treatment-naïve HIV patients with creatinine clearance (CrCl) ≥70 mL/min. Study 118 assessed the renal safety of COBI-containing regimens in HIV patients with mild to moderate renal impairment. MATERIAL AND METHODS: Phase 3, open label study in HIV-1-infected patients with CrCl 50-89 mL/min who are virologically suppressed on a stable regimen containing ritonavir (RTV)-boosted atazanavir (ATV) or darunavir (DRV). Patients switched RTV to COBI, while keeping the rest of their regimen unchanged. We present the 96-week (Wk) data. RESULTS: Seventy-three patients were enrolled. Mean age was 54 years; male 82%; white 77%; hypertension 38%; diabetes 18%; baseline proteinuria (≥trace) 51%; median CrCl 71 mL/min (range: 42-98). At Wk 96, 89% maintained virologic suppression (95% CI 77.4-95.8%). No emergent resistance developed. Reductions in CrCl (median [IQR]) were observed as early as Wk 2, after which they were nonprogressive through Wk 96 (Wk 48: -3.8 [-9-0.8]; Wk 96: -5.0 [-13.0-0.1]). Changes in CrCl by baseline CrCl (<70 vs ≥70) at Wk 96 were: -3.1 [-5.1-0.5] vs -7.6 [-15.2 to -3.6], respectively. Cystatin C-based eGFR remained stable through Wk 96 (median [IQR]: -2.8 [-7.4-8.9 mL/min/1.73 m(2)). Actual GFR assessment using CLiohexol (n=14) was unaffected over 24 Wks (median at baseline: 82.5, median changes from baseline at Wks 2, 4, and 24: 1.6, 7.0, -4.1 mL/min, respectively). Three renal discontinuations occurred (two worsening CrCl and one proteinuria/hematuria); none had proximal renal tubulopathy [PRT]. No patient had laboratory evidence of PRT (>1 confirmed renal laboratory abnormalities [increase in serum Cr≥0.4 mg/dL, ≥2-grade increase in proteinuria,≥1-grade increase in normoglycemic glycosuria or hypophosphatemia]). CONCLUSIONS: In HIV-infected patients with CrCl 50-89 mL/min, on ATV- or DRV-based regimen switching to COBI from RTV, demonstrated that COBI was well tolerated with no cases of PRT through 96 Wks. The renal safety profile of COBI in patients with mild to moderate renal impairment was consistent with the long-term data in patients without renal impairment (CrCl≥70 mL/min) from the phase 3 studies of COBI-containing regimens.

Fanconi syndrome accompanied by renal function decline with tenofovir disoproxil fumarate: a prospective, case-control study of predictors and resolution in HIV-infected patients.

OBJECTIVE: The predictors of Fanconi syndrome (FS) accompanied by renal function decline with use of the antiretroviral tenofovir disoproxil fumarate (TDF) have not been assessed. In addition, the natural history of renal recovery from FS after TDF discontinuation is not well-described. DESIGN: We prospectively enrolled HIV-infected patients receiving TDF with newly identified FS (defined as at least two markers of proximal tubulopathy and either a >25% decline in creatinine clearance (CrCl) from pre-TDF values or a CrCl <60 mL/min in those without a known pre-TDF CrCl) in a multicenter observational study. These case participants were matched 1:2 to controls; characteristics between the two groups were compared. Case participants with known pre-TDF CrCl values were then followed over 48 weeks to assess renal recovery. RESULTS: Nineteen cases and 37 controls were enrolled. In multivariable analysis, previous or concurrent use of lopinavir/ritonavir [OR 16.37, 95% CI (2.28, 117.68); P = 0.006] and reduced creatinine clearance prior to initiation of TDF [OR 1.44 for every 5 mL/min reduction, 95% CI (1.09, 1.92); P = 0.012; OR 19.77 for pre-TDF CrCl lower than 83 mL/min, 95% CI (2.24, 174.67); P = 0.007] were significantly associated with FS. Of the 14 cases followed for resolution, 7 (50%) achieved at least partial resolution (defined as recovering CrCl >70% of pre-TDF values) although most participants had full normalization of proximal tubulopathy markers within two months of TDF discontinuation. CONCLUSIONS: FS, defined by specific CrCl decreases and markers of tubulopathy, is more likely in those who have received or are currently receiving concomitant lopinavir/ritonavir or who had lower CrCl prior to TDF initiation. Half of those with protocol-defined FS had CrCl recover to near pre-TDF values during the first year after TDF discontinuation.

Use of glomerular filtration rate estimating equations for drug dosing in HIV-positive patients.

BACKGROUND: Current HIV treatment guidelines recommend using the Cockcroft-Gault equation for drug dosing adjustments. The use of newer glomerular filtration rate (GFR) estimating equations for drug dosing and the appropriateness of physician antiretroviral dosing based on estimated kidney function have not been studied in an HIV-positive population. METHODS: We evaluated concordance between measured and estimated GFR for the assignment of kidney function categories designated by the US Food and Drug Administration (FDA) Guidance for industry for pharmacokinetic studies, and appropriateness of physician antiretroviral drug dosing for level of kidney function in 200 HIV-positive patients on stable antiretroviral therapy. Estimated kidney function was determined using the Chronic Kidney Disease-Epidemiology collaboration (CKD-EPI), Modification of Diet in Renal Disease (MDRD) Study and Cockcroft-Gault equations. RESULTS: For assignment of FDA-designated kidney function categories, concordance rates between measured and estimated GFR using the CKD-EPI, MDRD Study and Cockcroft-Gault equations were 79%, 71% and 77%, respectively. This pattern was consistent across most subgroups. When actual prescribed dosages were compared with recommended dosages based on the level of estimated kidney function, 3-19% of study participants were prescribed higher than recommended dosages. The largest discordance between prescribed and recommended dosages was observed for the Cockcroft-Gault equation. CONCLUSIONS: The CKD-EPI equation has the highest concordance with measured GFR for the assignment of FDA-designated kidney function categories. Its use may lead to lower dosing-related errors in HIV-infected US adults on stable antiretroviral therapy. More education is required with respect to dose adjustment for level of kidney function.

Performance of creatinine and cystatin C GFR estimating equations in an HIV-positive population on antiretrovirals.

OBJECTIVE: To evaluate the performance of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) creatinine, cystatin C, and creatinine-cystatin C estimating equations in HIV-positive patients. METHODS: We evaluated the performance of the Modification of Diet in Renal Disease (MDRD) Study and CKD-EPI creatinine 2009, CKD-EPI cystatin C 2012, and CKD-EPI creatinine-cystatin C 2012 glomerular filtration rate (GFR) estimating equations compared with GFR measured using plasma clearance of iohexol in 200 HIV-positive patients on stable antiretroviral therapy. Creatinine and cystatin C assays were standardized to certified reference materials. RESULTS: Of the 200 participants, median (IQR) CD4 count was 536 (421) and 61% had an undetectable HIV viral load. Mean (SD) measured GFR (mGFR) was 87 (26) mL/min per 1.73 m. All CKD-EPI equations performed better than the MDRD Study equation. All 3 CKD-EPI equations had similar bias and precision. The cystatin C equation was not more accurate than the creatinine equation. The creatinine-cystatin C equation was significantly more accurate than the cystatin C equation, and there was a trend toward greater accuracy than the creatinine equation. Accuracy was equal or better in most subgroups with the combined equation compared to either alone. CONCLUSIONS: The CKD-EPI cystatin C equation does not seem to be more accurate than the CKD-EPI creatinine equation in patients who are HIV-positive, supporting the use of the CKD-EPI creatinine equation for routine clinical care for use in North American populations with HIV. The use of both filtration markers together as a confirmatory test for decreased estimated GFR based on creatinine in individuals who are HIV-positive requires further study.