Risks associated with antiretroviral treatment for human immunodeficiency virus (HIV): qualitative analysis of social media data and health state utility valuation.

PURPOSE: Despite benefits of antiretroviral therapies (ART), people with HIV infection have increased risk of cardiovascular disease, kidney disease, and low bone mineral density. Some ARTs increase risk of these events. The purpose of this study was to examine patients' perspectives of these risks and estimate health state utilities associated with these risks for use in cost-utility models. METHODS: Qualitative thematic analysis was conducted to examine messages posted to the POZ/AIDSmeds Internet community forums, focusing on bone, kidney, and cardiovascular side effects and risks of HIV/AIDS medications. Then, health state vignettes were drafted based on this qualitative analysis, literature review, and clinician interviews. The health states (representing HIV, plus treatment-related risks) were valued in time trade-off interviews with general population participants in the UK. RESULTS: Qualitative analysis of the Internet forums documented patient concerns about ART risks, as well as treatment decisions made because of these risks. A total of 208 participants completed utility interviews (51.4% female; mean age 44.6 years). The mean utility of the HIV health state (virologically suppressed, treated with ART) was 0.86. Adding a description of risk resulted in statistically significant disutility (i.e., utility decreases): renal risk (disutility = -0.02), bone risk (-0.03), and myocardial infarction risk (-0.05). CONCLUSIONS: Patient concerns and treatment decisions were documented via qualitative analysis of Internet forum discussions, and the impact of these concerns was quantified in terms of health state utilities. The resulting disutilities may be useful for differentiating among ARTs in economic modeling of treatment for patients with HIV.

Tenofovir alafenamide versus tenofovir disoproxil fumarate, coformulated with elvitegravir, cobicistat, and emtricitabine, for initial treatment of HIV-1 infection: two randomised, double-blind, phase 3, non-inferiority trials.

BACKGROUND: Tenofovir disoproxil fumarate can cause renal and bone toxic effects related to high plasma tenofovir concentrations. Tenofovir alafenamide is a novel tenofovir prodrug with a 90% reduction in plasma tenofovir concentrations. Tenofovir alafenamide-containing regimens can have improved renal and bone safety compared with tenofovir disoproxil fumarate-containing regimens. METHODS: In these two controlled, double-blind phase 3 studies, we recruited treatment-naive HIV-infected patients with an estimated creatinine clearance of 50 mL per min or higher from 178 outpatient centres in 16 countries. Patients were randomly assigned (1:1) to receive once-daily oral tablets containing 150 mg elvitegravir, 150 mg cobicistat, 200 mg emtricitabine, and 10 mg tenofovir alafenamide (E/C/F/tenofovir alafenamide) or 300 mg tenofovir disoproxil fumarate (E/C/F/tenofovir disoproxil fumarate) with matching placebo. Randomisation was done by a computer-generated allocation sequence (block size 4) and was stratified by HIV-1 RNA, CD4 count, and region (USA or ex-USA). 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 intention-to-treat efficacy and safety analyses. The main outcomes were the proportion of patients with plasma HIV-1 RNA less than 50 copies per mL at week 48 as defined by the the US Food and Drug Adminstration (FDA) snapshot algorithm (pre-specified non-inferiority margin of 12%) and pre-specified renal and bone endpoints at 48 weeks. These studies are registered with ClinicalTrials.gov, numbers NCT01780506 and NCT01797445. FINDINGS: We recruited patients from Jan 22, 2013, to Nov 4, 2013 (2175 screened and 1744 randomly assigned), and gave treatment to 1733 patients (866 given E/C/F/tenofovir alafenamide and 867 given E/C/F/tenofovir disoproxil fumarate). E/C/F/tenofovir alafenamide was non-inferior to E/C/F/tenofovir disoproxil fumarate, with 800 (92%) of 866 patients in the tenofovir alafenamide group and 784 (90%) of 867 patients in the tenofovir disoproxil fumarate group having plasma HIV-1 RNA less than 50 copies per mL (adjusted difference 2·0%, 95% CI -0·7 to 4·7). Patients given E/C/F/tenofovir alafenamide had significantly smaller mean serum creatinine increases than those given E/C/F/tenofovir disoproxil fumarate (0·08 vs 0·12 mg/dL; p<0·0001), significantly less proteinuria (median % change -3 vs 20; p<0·0001), and a significantly smaller decrease in bone mineral density at spine (mean % change -1·30 vs -2·86; p<0·0001) and hip (-0·66 vs -2·95; p<0·0001) at 48 weeks. INTERPRETATION: Through 48 weeks, more than 90% of patients given E/C/F/tenofovir alafenamide or E/C/F/tenofovir disoproxil fumarate had virological success. Renal and bone effects were significantly reduced in patients given E/C/F/tenofovir alafenamide. Although these studies do not have the power to assess clinical safety events such as renal failure and fractures, our data suggest that E/C/F/tenofovir alafenamide will have a favourable long-term renal and bone safety profile. FUNDING: Gilead Sciences.

Week 144 resistance analysis of elvitegravir/cobicistat/emtricitabine/tenofovir DF versus atazanavir+ritonavir+emtricitabine/tenofovir DF in antiretroviral-naïve patients.

OBJECTIVE: To describe baseline and emergent HIV-1 resistance to elvitegravir/ cobicistat/emtricitabine/tenofovir DF (EVG/COBI/FTC/TDF) and ritonavir-boosted atazanavir/emtricitabine/tenofovir DF (ATV+RTV+FTC/TDF) in HIV-1-infected, treatment-naïve subjects through 144 weeks. METHOD: This was a randomized, double-blind, phase 3 study. HIV-1 protease (PR) and reverse transcriptase (RT) were sequenced at screening. Genotypic and phenotypic analyses were performed at virologic failure confirmation and retrospectively at baseline for PR, RT, and integrase (IN) for patients with virologic failure through week 144. RESULTS: In the EVG/ COBI/FTC/TDF group through week 144, HIV-1 from 8 patients (2.3%; 8/353 treated patients) developed primary IN strand transfer inhibitor (INSTI) (n = 6) and/or nucleoside RT inhibitor (NRTI) resistance substitutions (n = 7). The emergence of resistance decreased after the first year, with 5 patients developing HIV-1 resistance through week 48, 1 from weeks 48-96, and 2 from weeks 96-144. Emergent substitutions were E92Q, N155H, or Q148R (n = 2 each) and T66I or T97A (n = 1 each) in IN and M184V/I (n = 7) and K65R (n = 1) in RT. All 8 isolates had reduced susceptibility to EVG, FTC, or TDF. Virus with EVG phenotypic resistance showed cross-resistance to raltegravir. In the ATV+RTV+FTC/TDF group, HIV-1 from 2 patients (0.6%; 2/355 treated patients; both at week 144) developed the resistance substitution M184V/I in RT. CONCLUSIONS: Resistance development to EVG/COBI/FTC/TDF was infrequent (2.3%) through 144 weeks of therapy and decreased over time, consistent with durable efficacy.

Cobicistat-boosted darunavir in HIV-1-infected adults: week 48 results of a Phase IIIb, open-label single-arm trial.

BACKGROUND: Cobicistat is an alternative pharmacoenhancer to ritonavir. In healthy volunteers, darunavir exposure was comparable when darunavir 800 mg once daily was co-administered with cobicistat 150 mg once daily (as single agents or a fixed-dose combination) vs. with ritonavir 100 mg once daily. METHODS: This 48-week, Phase IIIb, single-arm, US multicenter study (NCT01440569) evaluated safety, efficacy and pharmacokinetics of darunavir/cobicistat 800/150 mg once daily (as single agents) plus two investigator-selected nucleoside/tide reverse transcriptase inhibitors (N[t]RTIs) in HIV-1-infected adults. Patients had no darunavir resistance-associated mutations (RAMs), plasma viral load (VL) ≥1000 HIV-1 RNA copies/ml, eGFR ≥80 ml/min and genotypic sensitivity to the two N[t]RTIs. The primary endpoint was any treatment-emergent grade 3 or 4 adverse events (AEs) through Week 24. RESULTS: The majority of the 313 intent-to-treat patients were treatment-naïve (295/313; 94%), male (89%), White (60%) and received a tenofovir-based regimen (99%). Median baseline VL and CD4(+) count overall were 4.8 log10 HIV-1 RNA copies/ml and 361 cells/mm(3), respectively. Overall, 86% of patients (268/313) completed the study. The majority of discontinuations were for AEs (15/313; 5%). The incidence of treatment-emergent grade 3 or 4 AEs regardless of causality was 6% through Week 24 and 8% through Week 48. Most common AEs through Week 48 were diarrhea (27%) and nausea (23%), which were grade 1 or 2 in severity. Week 48 virologic response rates (% with VL <50 HIV-1 RNA copies/ml; Snapshot analysis) were 81% overall and 83% in treatment-naïve patients; median increases in CD4(+) count at 48 weeks were 167 and 169 cells/mm(3), respectively. Of 15/313 patients who met the criteria for resistance analysis, one developed a darunavir RAM as a mixture with wild-type (I84I/V), without phenotypic resistance to darunavir. The mean population pharmacokinetic-derived darunavir areas under the plasma concentration-time curve were 102,000 overall and 100,620 ng•h/ml in treatment-naïve patients. No clinically relevant relationships were seen between darunavir exposure and virologic response, AEs or laboratory parameters. CONCLUSION: Darunavir/cobicistat 800/150 mg once daily was generally well tolerated through Week 48, with no new safety concerns. Pharmacokinetics, virologic and immunologic responses for darunavir/cobicistat were similar to previous data for darunavir/ritonavir 800/100 mg once daily.

Brief Report: Switching to Tenofovir Alafenamide, Coformulated With Elvitegravir, Cobicistat, and Emtricitabine, in HIV-Infected Adults With Renal Impairment: 96-Week Results From a Single-Arm, Multicenter, Open-Label Phase 3 Study.

Tenofovir disoproxil fumarate is associated with renal and bone toxicity. In a single-arm, open-label study of 242 virologically suppressed, HIV-infected participants with creatinine clearance 30-69 mL/min who switched to elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide, participants had stable creatinine clearance, significant and durable improvements in proteinuria, albuminuria, and tubular proteinuria (P < 0.001), and significant increases in hip and spine bone mineral density through 96 weeks (P < 0.001). Eighty-eight percent maintained HIV-1 RNA <50 c/mL at week 96. These longer-term results support the use of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide in HIV-infected individuals with mild-moderately impaired renal function.

A Randomized, Open-Label Trial to Evaluate Switching to Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide Plus Darunavir in Treatment-Experienced HIV-1-Infected Adults.

BACKGROUND: HIV-infected, treatment-experienced adults with a history of prior resistance and regimen failure can be virologically suppressed but may require multitablet regimens associated with lower adherence and potential resistance development. METHODS: We enrolled HIV-infected, virologically suppressed adults with 2-class to 3-class drug resistance and at least 2 prior regimen failures into this phase 3, open-label, randomized study. The primary endpoint was the percentage of participants with HIV-1 RNA <50 copies per milliliter at week 24 [Food and Drug Administration (FDA) snapshot algorithm]. RESULTS: For 135 participants [elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) plus darunavir (DRV), n = 89; baseline regimen, n = 46], most of whom were taking a median of 5 tablets/d, simplification to E/C/F/TAF plus DRV was noninferior to continuation of baseline regimens at week 24 (plasma HIV-1 RNA <50 copies per milliliter: 96.6% vs. 91.3%, difference 5.3%, 95.001% CI: -3.4% to 17.4%). E/C/F/TAF plus DRV met prespecified criteria for noninferiority and superiority at week 48 for the same outcome. E/C/F/TAF plus DRV was well tolerated and had an improved renal safety profile compared with baseline regimens, with statistically significant differences between groups in quantitative total proteinuria and markers of proximal tubular proteinuria. Compared with baseline regimens, participants who switched to E/C/F/TAF plus DRV reported higher mean treatment satisfaction scale total scores and fewer days with missed doses. CONCLUSIONS: This study demonstrated that regimen simplification from a 5-tablet regimen to the 2-tablet, once-daily combination of E/C/F/TAF plus DRV has durable maintenance of virologic suppression and improvements in specific markers of renal safety. Such a strategy may lead to greater adherence and improved quality of life.

Tenofovir alafenamide: A novel prodrug of tenofovir for the treatment of Human Immunodeficiency Virus.

Despite substantial progress in the development of antiretroviral regimens that durably suppress Human Immunodeficiency Virus (HIV) infection, new agents that maintain high efficacy while further optimizing the safety of lifelong, chronic therapy are needed. Tenofovir alafenamide (TAF; formerly known as GS-7340) is a novel prodrug of the antiviral acyclic nucleoside phosphonate tenofovir (TFV) with improved properties relative to tenofovir disoproxil fumarate (TDF). Although potent and generally well tolerated, TDF therapy has been associated with changes in markers of renal function, decreases in bone mineral density and a rare occurrence of serious renal adverse events, including Fanconi's Syndrome. The renal and bone toxicity observed with TDF is associated with high circulating plasma levels of TFV. TAF was discovered to be a more efficient prodrug able to further refine HIV therapy and better address life-long therapy in an older and increasingly comorbid HIV infected population. By enhancing stability in biological matrices while being rapidly activated in cells, TAF produces higher levels of intracellular TFV diphosphate, the pharmacologically active metabolite, in HIV-target cells at substantially reduced oral doses of TFV equivalents. All TFV released in the body is eventually eliminated renally; therefore, lowering the TFV equivalents administered reduces off-target kidney exposure. Effective therapy is thus achieved at approximately 90% lower systemic exposure to TFV, translating to statistically and clinically significant improvement in safety parameters associated with bone mineral density and markers of renal function.

Equivalent Decline in Inflammation Markers with Tenofovir Disoproxil Fumarate vs. Tenofovir Alafenamide.

BACKGROUND: Initiation of antiretroviral therapy (ART) and subsequent virologic suppression reduces immune activation and systemic inflammation. METHODS: We examined longitudinal changes in biomarkers of monocyte activation (sCD14, sCD163), and systemic (IL-6, hsCRP, sTNFR-I and D-dimer) and vascular (Lp-PLA2) inflammation in a subgroup (N=100 per arm) of participants enrolled in a randomized, placebo-controlled trial comparing elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF; TAF) to E/C/F/tenofovir disoproxil fumarate (E/C/F/TDF; TDF) in treatment-naïve adults. RESULTS: For 194 participants (TAF, 98; TDF, 96), baseline levels of biomarkers did not differ by treatment arm; there were no differences in biomarker values between groups at weeks 12, 24, or 48 (p>0.05), except IL-6 at week 12 (p=0.012). Among all participants (combining groups), there were statistically significant declines from baseline observed for D-dimer, sCD163, and sTNFR-1 by week 12 and IL-6 by week 24. The proportion of participants with Lp-LA2 levels<200ng per mL (p=0.250) or hsCRP levels <3000mg per L (p=0.586) was unchanged through week 48. CONCLUSIONS: We observed equivalent declines in biomarkers of monocyte activation and systemic inflammation in treatment-naïve adults treated with TAF or TDF for 48weeks, suggesting that TAF and TDF have equivalent impact on immune activation and inflammation.

Switching to Tenofovir Alafenamide, Coformulated With Elvitegravir, Cobicistat, and Emtricitabine, in HIV-Infected Patients With Renal Impairment: 48-Week Results From a Single-Arm, Multicenter, Open-Label Phase 3 Study.

BACKGROUND: Tenofovir alafenamide (TAF) is a novel tenofovir prodrug with improved renal and bone safety compared with TDF-containing regimens. We report the 48 week safety and efficacy of a once-daily single tablet regimen of elvitegravir 150 mg (E), cobicistat 150 mg (C), emtricitabine 200 mg (F), and TAF 10 mg (E/C/F/TAF) in HIV-1-infected patients with mild to moderate renal impairment. METHODS: We enrolled virologically suppressed HIV-1-infected subjects with estimated creatinine clearance (CrCl) 30-69 mL/min in a single-arm, open-label study to switch regimens to E/C/F/TAF. The primary endpoint was the change from baseline in glomerular filtration rate estimated using various formulae. This study is registered with ClinicalTrials.gov, number NCT01818596. FINDINGS: We enrolled and treated 242 patients with mean age 58 years, 18% Black, 39% hypertension, 14% diabetes. Through week 48, no significant change in estimated CrCl was observed. Two patients (0.8%) discontinued study drug for decreased creatinine clearance, neither had evidence of renal tubulopathy and both had uncontrolled hypertension. Subjects had significant improvements in proteinuria, albuminuria, and tubular proteinuria (P < 0.001 for all). Hip and spine bone mineral density significantly increased from baseline to week 48 (mean percent change +1.47 and +2.29, respectively, P < 0.05). Ninety-two percent (222 patients) maintained HIV-1 RNA <50 copies per milliliter at week 48. INTERPRETATION: Switch to E/C/F/TAF was associated with minimal change in GFR. Proteinuria, albuminuria and bone mineral density significantly improved. These data support the efficacy and safety of once daily E/C/F/TAF in HIV+ patients with mild or moderate renal impairment without dose adjustment.

Tenofovir alafenamide vs. tenofovir disoproxil fumarate in single tablet regimens for initial HIV-1 therapy: a randomized phase 2 study.

OBJECTIVES: To evaluate the safety and efficacy of the novel tenofovir prodrug, tenofovir alafenamide (TAF), as part of a single-tablet regimen (STR) for the initial treatment of HIV-1 infection. DESIGN: Phase 2, randomized, double-blind, double-dummy, multicenter, active-controlled study. METHODS: Antiretroviral naive adults with HIV-1 RNA ≥5000 copies per milliliter and a CD4 count ≥50 cells per microliter were randomized 2:1 to receive an STR of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide (E/C/F/TAF) or elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (E/C/F/TDF), plus placebo for 48 weeks. RESULTS: Patients on both E/C/F/TAF (n = 112) and E/C/F/TDF (n = 58) had high rates of virologic suppression (<50 HIV copies per milliliter) at week 24 (86.6%; 89.7%) and at week 48 (88.4%; 87.9%), and had similar improvements in CD4 at week 48 (177; 204), respectively. Both treatments were well tolerated, and most adverse events were self-limiting and of mild to moderate severity. Compared with patients on E/C/F/TDF, patients on E/C/F/TAF had smaller reductions in estimated creatinine clearance (-5.5 vs. -10.1 mL/min, P = 0.041), significantly less renal tubular proteinuria, and smaller changes in bone mineral density for hip (-0.62% vs. -2.39%, P < 0.001) and spine (-1.00% vs. -3.37%, P < 0.001). Patients on E/C/F/TAF had higher increases in total cholesterol, low-density lipoprotein, and high-density lipoprotein, but the total cholesterol/high-density lipoprotein ratio was unchanged for both. CONCLUSIONS: Treatment-naive patients given the STR that contained either TAF or TDF achieved a high rate of virologic success. Compared with those receiving TDF, patients on E/C/F/TAF experienced significantly smaller changes in estimated creatinine clearance, renal tubular proteinuria, and bone mineral density.

Phase IIIb, open-label single-arm trial of darunavir/cobicistat (DRV/COBI): Week 48 subgroup analysis of HIV-1-infected treatment-nave adults.

INTRODUCTION: COBI, a PK enhancer with no ARV activity is a more selective cytochrome P450 (CYP)3A inhibitor than ritonavir (RTV), does not induce CYP isozymes, and thus has less potential for drug-drug interactions. COBI boosts DRV PK as effectively as RTV in healthy volunteers. MATERIALS AND METHODS: This 48-week, phase IIIb, open-label, single-arm, US multicentre study (NCT01440569) included HIV-infected treatment-nave and experienced adults with no DRV RAMs, viral load (VL) ≥1000 c/mL, eGFR ≥80 mL/min and genotypic sensitivity to investigator-selected N[t]RTIs. Patients received DRV/COBI 800/150 mg qd (as single agents) plus two fully active N[t]RTIs. The primary endpoint was any treatment-emergent grade 3 or 4 AEs through Week 24. We report 48-week safety, efficacy and PK/PD results in treatment-nave patients. RESULTS: Of 313 ITT patients, 295 were treatment-nave (94%). In the treatment-nave cohort, 90% were male, 60% white and 294 (99.7%) received a TDF-containing regimen. Median baseline (BL) VL was 4.8 log10 c/mL and CD4(+) 370 cells/mm(3). Treatment-emergent grade 3 or 4 AEs regardless of causality were reported in 21 (7%) patients. AEs regardless of causality (any grade; ≥10% of patients) were: diarrhoea (27%), nausea (23%), URTI (15%) and headache (12%). Sixteen (5%) patients had AEs leading to study drug discontinuation, most frequently rash (three patients), hypersensitivity and nausea (two patients each). Consistent with the known inhibition of tubular creatinine secretion by COBI, there was a mean increase from BL in serum creatinine by week 2 (0.09 mg/dL), remaining stable through week 48 (mean 0.10 mg/dL increase from BL). At week 48, 83% of patients achieved VL<50 c/mL; FDA Snapshot); median increase in CD4(+) was 169 cells/mm(3). Eight patients met the criteria for resistance testing. M184V was detected in one pt receiving FTC. New primary RAMs were not detected in the other seven patients. The mean population PK-derived DRV AUC24h was 100,620 ng.h/mL and C0h 2,105 ng/mL (n=281). There were no clinically relevant relationships between DRV exposure and virologic response, AEs or laboratory parameters. CONCLUSIONS: The DRV PK of DRV/COBI was consistent with historical data for DRV/RTV. DRV/COBI 800/150 mg qd plus two N(t)RTIs had an 83% response and was well tolerated through Week 48. These results are similar to published data for DRV/RTV 800/100 mg qd, and support the use of DRV/COBI 800/150 mg qd in treatment-nave patients.

Anti-CD4 monoclonal antibody ibalizumab exhibits breadth and potency against HIV-1, with natural resistance mediated by the loss of a V5 glycan in envelope.

OBJECTIVES: Passive immunization for the prevention of HIV-1 infection is currently being reenergized. The anti-CD4 monoclonal antibody ibalizumab has demonstrated safety and efficacy in phase 1 and 2 clinical trials for treatment of HIV-1 infection and is undergoing a phase 1 clinical trial in HIV-1 uninfected individuals for prevention. Here, we sought to assess ibalizumab antiviral breadth and potency and to identify determinants of natural preexisting resistance. METHODS: Ibalizumab breadth and potency was assessed against a large clinically relevant panel of HIV-1 pseudoviruses (n = 116) commonly used to assess vaccine candidates. Determinants of resistance were assessed by sequence analysis. RESULTS: Ibalizumab neutralized 92% and 66% of viruses as defined by 50% and 80% inhibition, respectively. Median in vitro neutralization potency by IC50 was 0.03 µg/mL, substantially lower than the broadly neutralizing mAbs, PG9, or VRC01. The dominant determinant of resistance was the absence of a potential N-linked glycosylation site (PNGS) at the V5 N-terminus (P < 0.001), with the V2 loop length possibly influencing the degree of resistance afforded by the absence of the V5 N-terminal PNGS (P = 0.001). Other significant independent correlates of resistance included PNGS at position 386 and the side chain length of residue 375. Ibalizumab exhibited complementary resistance to VRC01 (P = 0.006) and sCD4 (P < 0.001), in part mediated by the V5 PNGS. CONCLUSIONS: Ibalizumab breadth and potency compared favorably with broadly neutralizing anti-HIV-1 monoclonal antibodies, supporting the clinical development of ibalizumab, alone or in combination, for HIV-1 prevention.

A randomized, double-blind comparison of coformulated elvitegravir/cobicistat/emtricitabine/tenofovir DF vs ritonavir-boosted atazanavir plus coformulated emtricitabine and tenofovir DF for initial treatment of HIV-1 infection: analysis of week 96 results.

This ongoing, randomized, double-blind, active-controlled phase 3 international trial demonstrated the noninferior efficacy of elvitegravir/cobicistat/emtricitabine/tenofovir DF (EVG/COBI/FTC/TDF) compared with atazanavir boosted by ritonavir (ATV/RTV) plus emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) at 48 weeks. Here, we report the week 96 results. Of 708 treated subjects, virological success (Food and Drug Administration snapshot) was maintained at week 96 with EVG/COBI/FTC/TDF and ATV/RTV + FTC/TDF (83% vs 82%, difference 1.1%, 95% confidence interval -4.5% to 6.7%). Study drug discontinuations due to adverse events were low (4% vs 6%). Median increases from baseline in serum Cr (mg/dL) in EVG/COBI/FTC/TDF vs ATV/RTV + FTC/TDF at week 96 (0.12 vs 0.08) were similar to those at week 48 (0.12 vs 0.08). EVG/COBI/FTC/TDF showed similar mean decreases (%) in bone mineral density from baseline vs ATV/RTV + FTC/TDF (hip: -3.16 vs -4.19, P = 0.069; spine: -1.96 vs -3.54, P = 0.049). Overall, week 96 results support durable efficacy and safety of EVG/COBI/FTC/TDF in HIV-1-infected patients.

Antiviral activity, safety, and pharmacokinetics/pharmacodynamics of tenofovir alafenamide as 10-day monotherapy in HIV-1-positive adults.

OBJECTIVE: To evaluate the antiviral activity, safety, pharmacokinetics, and pharmacokinetics/pharmacodynamics of short-term monotherapy with tenofovir alafenamide (TAF), a next-generation tenofovir (TFV) prodrug. DESIGN: A phase 1b, randomized, partially blinded, active- and placebo-controlled, dose-ranging study. METHODS: Treatment-naive and experienced HIV-1-positive adults currently off antiretroviral therapy were randomized to receive 8, 25, or 40 mg TAF, 300 mg tenofovir disoproxil fumarate (TDF), or placebo, each once daily for 10 days. RESULTS: Thirty-eight subjects were enrolled. Baseline characteristics were similar across dose groups. Significant reductions in plasma HIV-1 RNA from baseline to day 11 were observed for all TAF dose groups compared with placebo (P < 0.01), with a median decrease of 1.08-1.73 log10 copies per milliliter, including a dose-response relationship for viral load decrease up to 25 mg. At steady state, 8, 25, and 40 mg TAF yielded mean TFV plasma exposures [area under the plasma concentration-time curve (AUCtau)] of 97%, 86%, and 79% lower, respectively, as compared with the TFV exposures observed with 300 mg TDF. For 25 and 40 mg TAF, the mean intracellular peripheral blood mononuclear cell tenofovir diphosphate AUCtau was ∼7-fold and ∼25-fold higher, relative to 300 mg TDF. CONCLUSIONS: Compared with 300 mg TDF, TAF demonstrated more potent antiviral activity, higher peripheral blood mononuclear cell intracellular tenofovir diphosphate levels, and lower plasma TFV exposures, at approximately 1/10th of the dose. This may translate into greater antiviral efficacy, a higher barrier to resistance, and an improved safety profile relative to TDF, supporting further investigation of TAF dosed once daily in HIV-infected patients.