Comparison of Dried Blood Spots Versus Conventional Plasma Collection for the Characterization of Efavirenz Pharmacokinetics in a Large-Scale Global Clinical Trial-The ENCORE1 Study.

BACKGROUND: The aim of this study was to determine the utility of dried blood spots (DBS) compared with conventional plasma collection methods for characterization of efavirenz pharmacokinetics, in the setting of a large-scale, global clinical trial (ENCORE1). METHODS: Six hundred thirty patients were recruited from 38 sites and had single matched whole blood DBS and plasma samples (mid-dose interval) taken at weeks 4 and 12 of treatment. In addition, a subgroup of patients underwent intensive DBS and plasma sampling (0-24 hours) to provide full-profile data for pharmacokinetic parameters. Efavirenz concentrations were determined by validated high-performance liquid chromatography-mass spectrometry methods. A DBS-predicted plasma concentration was derived and linear regression and Bland-Altman plots were used to compare DBS-predicted plasma concentrations with that of measured plasma concentrations. RESULTS: Efavirenz DBS and plasma concentrations were significantly correlated (R = 0.904, P < 0.001; n = 1094), and DBS concentrations were, on average, 53% ± 9.5% lower than plasma. In the main study, the DBS-predicted plasma values significantly underestimated the true measured concentration of efavirenz in plasma; the mean difference (95% confidence interval) between efavirenz DBS-predicted concentrations and measured plasma concentrations was -0.451 mg/L (-0.504 to -0.398) at week 4 (n = 561). However, in the intensive study, the mean difference was only 0.086 mg/L (-0.006 to 0.178) at 12 hours after dose (n = 46) and was not statistically significant. CONCLUSIONS: Our data show a high correlation between measurements of efavirenz concentrations in plasma and in DBS. However, DBS concentrations significantly underestimated the true measured plasma concentrations in the sparse samples taken in this large multinational ENCORE1 trial.

Nonnucleoside Reverse-transcriptase Inhibitor- vs Ritonavir-boosted Protease Inhibitor-based Regimens for Initial Treatment of HIV Infection: A Systematic Review and Metaanalysis of Randomized Trials.

BACKGROUND: Previous studies suggest that nonnucleoside reverse-transcriptase inhibitors (NNRTIs) cause faster virologic suppression, while ritonavir-boosted protease inhibitors (PI/r) recover more CD4 cells. However, individual trials have not been powered to compare clinical outcomes. METHODS: We searched databases to identify randomized trials that compared NNRTI- vs PI/r-based initial therapy. A metaanalysis calculated risk ratios (RRs) or mean differences (MDs), as appropriate. Primary outcome was death or progression to AIDS. Secondary outcomes were death, progression to AIDS, and treatment discontinuation. We calculated RR of virologic suppression and MD for an increase in CD4 cells at week 48. RESULTS: We included 29 trials with 9047 participants. Death or progression to AIDS occurred in 226 participants in the NNRTI arm and in 221 in the PI/r arm (RR, 1.03; 95% confidence interval, .87-1.22; 12 trials; n = 3825), death in 205 participants in the NNRTI arm vs 198 in the PI/r arm (1.04; 0.86-1.25; 22 trials; n = 8311), and progression to AIDS in 140 participants in the NNRTI arm vs 144 in the PI/r arm (1.00; 0.80-1.25; 13 trials; n = 4740). Overall treatment discontinuation (1.12; 0.93-1.35; 24 trials; n = 8249) and from toxicity (1.21; 0.87-1.68; 21 trials; n = 6195) were comparable, but discontinuation due to virologic failure was more common with NNRTI (1.58; 0.91-2.74; 17 trials; n = 5371). At week 48, there was no difference between NNRTI and PI/r in virologic suppression (RR, 1.03; 0.98-1.09) or CD4(+) recovery (MD, -4.7 cells; -14.2 to 4.8). CONCLUSIONS: We found no difference in clinical and viro-immunologic outcomes between NNRTI- and PI/r-based therapy.

Cerebrospinal fluid exposure of efavirenz and its major metabolites when dosed at 400 mg and 600 mg once daily: a randomized controlled trial.

BACKGROUND: The optimal penetration of antiretroviral agents into the central nervous system may be a balance between providing adequate drug exposure to inhibit human immunodeficiency virus (HIV) replication while avoiding concentrations associated with neuronal toxicities. METHODS: Cerebrospinal fluid (CSF) exposure of efavirenz and the metabolites 7-hydroxy (7OH) and 8-hydroxy (8OH) efavirenz were assessed after at least 12 weeks of therapy in HIV-infected subjects randomized to commence antiretroviral regimens containing efavirenz at either 400 mg or 600 mg once daily. RESULTS: Of 28 subjects (14 and 14 on efavirenz 400 mg and 600 mg, respectively), CSF HIV RNA was undetectable in all. Geometric mean CSF efavirenz, 7OH-, and 8OH-efavirenz concentrations (with 90% confidence intervals [CIs]) for the 400-mg and 600-mg dosing groups were 16.5 (13-21) and 19.5 (15-25) ng/mL; 0.6 (.4-.9) and 0.6 (.4-1) ng/mL; and 5.1 (4.0-6.4) and 3.1 (2.1-4.4) ng/mL, respectively. Efavirenz concentration in CSF was >0.51 ng/mL (proposed CSF 50% maximal inhibitory concentration for wild-type virus) in all subjects, and 8OH-efavirenz concentration in CSF was >3.3 ng/mL (a proposed toxicity threshold) in 11 of 14 and 7 of 14 subjects randomized to the 400 mg and 600 mg doses of efavirenz, respectively. Whereas CSF efavirenz concentration was significantly associated with plasma concentration (P < .001) and cytochrome P450 2B6 genotype (CSF efavirenz GG to GT/TT geometric mean ratio, 0.56 [90% CI, .42-.74]), CSF 8OH-efavirenz concentration was not (P = .242 for association and CSF 8OH-efavirenz GG to GT/TT geometric mean ratio, 1.52 [90% CI, .97-2.36]). CONCLUSIONS: With both doses of efavirenz studied, CSF concentrations were considered adequate to inhibit HIV replication, although concentrations of 8OH-efavirenz were greater than those reportedly associated with neuronal toxicity. CSF exposure of 8OH-efavirenz was not dependent on plasma exposure and, as we postulate, may be subject to saturable pharmacokinetic effects. CLINICAL TRIALS REGISTRATION: NCT01011413.

A validated method for quantification of efavirenz in dried blood spots using high-performance liquid chromatography-mass spectrometry.

BACKGROUND: Efavirenz (EFV) is one of the preferred components of first-line antiretroviral treatment. EFV is characterized by a long plasma half-life (40-55 hours) with large interpatient variability, which raises the potential for individualization of therapy. Analyses of EFV levels in plasma require specialized facilities (cold storage/transport) which, in resource-limited settings, can be problematic; dried blood spots (DBS)-EFV measurements thus provide a cheap easy alternative for therapeutic drug monitoring. Our aim was to develop and validate a liquid chromatography-mass spectrometry method to quantify EFV in DBS collected as part of clinical trials in resource-limited settings. METHODS: DBS for standards, quality control samples, and patient samples were excised and then extracted with ethyl acetate/n-hexane (50/50 vol/vol) after addition of internal standard hexobarbital, and 1 mol/L K2CO3. The extract was evaporated to dryness, the residue reconstituted in mobile phase and analyzed directly by liquid chromatography-mass spectrometry. Gradient elution was on a reverse-phase C18 column using 1 mmol/L ammonium acetate in water and acetonitrile. Quantification was by selected reaction monitoring in negative ionization mode. DBS samples were obtained at several time points over 24 hours from HIV+ patients on either 400 or 600 mg EFV in combination with emtricitabine/tenofovir. RESULTS: The internal standard and EFV eluted at 2.68 and 3.54 minutes, respectively in a 5-minute run time. Matrix effects were minimal (-5.4%). Calibration curves were validated over a concentration range of 25-5000 ng/mL. Intra-assay and interassay variations ranged between 6.7% and 8.7% for imprecision and 100.3% and 104.2% for accuracy. Mean recovery was >64%. The DBS data showed a strong positive correlation with a validated plasma EFV assay (R = 0.9764, P < 0.001). EFV concentrations from DBS were approximately 42% lower than the paired plasma values, and the ratio of blood/plasma did not change over the dosing interval. CONCLUSIONS: The validated assay is now routinely applied to clinical samples measuring DBS EFV for pharmacokinetic analysis. The methodology is robust, accurate, and sensitive.

Pharmacokinetics of lamivudine and lamivudine-triphosphate after administration of 300 milligrams and 150 milligrams once daily to healthy volunteers: results of the ENCORE 2 study.

There is interest in evaluating the efficacy of lower doses of certain antiretrovirals for clinical care. We determined here the bioequivalence of plasma lamivudine (3TC) and intracellular 3TC-triphosphate (3TC-TP) concentrations after the administration of two different doses. ENCORE 2 was a randomized crossover study. Subjects received 3TC at 300 and 150 mg once daily for 10 days (arm 1; n = 13) or vice versa (arm 2; n = 11), separated by a 10-day washout. Pharmacokinetic (PK) profiles (0 to 24 h) were assessed on days 10 and 30. Plasma 3TC and 3TC-TP levels in peripheral blood mononuclear cells were quantified by high-performance liquid chromatography-tandem mass spectrometry. Within-subject changes in PK parameters (the area under the concentration-time curve from 0 to 24 h [AUC(0-24)], the trough concentration of drug in plasma at 24 h [C(24)], and the maximum concentration of drug in plasma [C(max)]) were evaluated by determining the geometric mean ratios (GMRs) adjusted for study arm, period, and intra-individual variation. Regimens were considered bioequivalent if the 90% confidence interval (90% CI) fell within the range of 0.8 to 1.25. A total of 24 subjects completed the study. The GM (90% CI) 3TC AUC(0-24)), expressed as ng·h/ml, for the 300- and 150-mg doses were 8,354 (7,609 to 9,172) and 4,773 (4,408 to 5,169), respectively. Bioequivalence in 3TC PK following the administration of 300 and 150 mg was not demonstrated: the GMRs for AUC(0-24), C(24), and C(max) were 0.57 (0.55 to 0.60), 0.63 (0.59 to 0.67), and 0.56 (0.53 to 0.60), respectively. The GM (90% CI) 3TC-TP AUC(0-24) values (pmol·h/10(6) cells) for the 300- and 150-mg doses were 59.5 (51.8 to 68.3) and 44.0 (38.0 to 51.0), respectively. Bioequivalence in 3TC-TP PK following the administration of 300 and 150 mg was not demonstrated: the GMRs for AUC(0-24), C(24), and C(max) were 0.73 (0.64 to 0.83), 0.82 (0.68 to 0.99), and 0.70 (0.61 to 0.82), respectively. We found that 3TC at 150 mg is not bioequivalent to the standard regimen of 300 mg, indicating that saturation of cytosine phosphorylation pathways is not achieved at a dose of 150 mg.

Two patterns of cerebral metabolite abnormalities are detected on proton magnetic resonance spectroscopy in HIV-infected subjects commencing antiretroviral therapy.

INTRODUCTION: Cerebral function impairment remains problematic in subjects with chronic human immunodeficiency virus (HIV) infection despite effective combination antiretroviral therapy (cART). Using cerebral proton magnetic resonance spectroscopy ((1)H MRS), we aimed to determine if abnormalities could be detected in neurologically asymptomatic HIV-infected subjects electively commencing cART. METHODS: Therapy-naive, HIV-infected individuals and HIV-uninfected controls underwent (1)H MRS in several anatomical voxels including the mid-frontal grey matter (FGM) and right basal ganglia (RBG). Differences in cerebral metabolite ratios between groups and correlations between immune and virological status were assessed. RESULTS: Forty-six subjects were recruited (26 HIV-infected and 20 control subjects). In the HIV-infected group, mean CD4+ count (SD, cells per microlitre) and plasma HIV RNA (SD, log10 copies per millilitre) were 192 (86) and 4.71 (0.64), respectively. Choline (Cho)/Creatine (Cr) and myoinositol (MI)/Cr ratios were significantly lower in the FGM in HIV-infected subjects compared to controls (0.67 (0.14) versus 0.88 (0.49), p = 0.036, and 0.94 (0.28) and 1.17 (0.26), p = 0.008, for Cho/Cr and MI/Cr, respectively) and Cho/Cr ratio associated with CD4+ lymphocyte count (p = 0.041). N-Acetyl-aspartate (NAA)/Cho ratio was significantly lower in the RBG in HIV-infected subjects compared to controls (2.27 (0.54) versus 2.63 (0.68), p = 0.002), and this was associated with greater plasma HIV RNA load (p = 0.014). CONCLUSIONS: Two patterns of cerebral metabolite abnormalities were observed in HIV-infected subjects electively commencing cART. Greater inflammatory metabolite ratios (Cho/Cr and MI/Cr) associated with lower markers of peripheral immune markers (CD4+ lymphocyte count) in the FGM and lower neuronal metabolite ratios (NAA/Cho) associated with greater HIV viraemia in the RBG were present in HIV-infected subjects.

Pharmacokinetics of plasma lopinavir/ritonavir following the administration of 400/100 mg, 200/150 mg and 200/50 mg twice daily in HIV-negative volunteers.

OBJECTIVES: Data suggest that some licensed antiretroviral doses could be reduced. We assessed the safety, tolerability and pharmacokinetics of lopinavir/ritonavir at doses of 400/100, 200/150 and 200/50 mg twice daily in HIV-negative volunteers (http://clinicaltrials.gov/ct2/show/NCT00985543). METHODS: Male and female volunteers were administered lopinavir/ritonavir at doses of 400/100 mg (two lopinavir/ritonavir Meltrex 200/50 mg tablets, Regimen 1), 200/150 mg (one Meltrex tablet, one 100 mg ritonavir capsule, Regimen 2) and 200/50 mg (one Meltrex tablet, Regimen 3). Each dose was given twice daily for 7 days sequentially, separated by a 7 day wash-out period. Lopinavir/ritonavir steady-state pharmacokinetics was assessed over 12 h at the end of each phase (days 7, 21 and 35). Pharmacokinetic parameters were compared using the 400/100 mg twice daily dose as reference, by determining geometric mean ratios (GMRs) and 90% confidence intervals. RESULTS: Twenty-two subjects (eight females) completed the study. Lopinavir AUC(0-12) (ng h/mL), C(max) (ng/mL) and the minimum concentration (C(trough)) (ng/mL) for the 400/100, 200/150 and 200/50 mg twice daily doses, respectively, were as follows: 99,599, 73,603 and 45,146; 11,965, 8939 and 6404; and 5776, 4293 and 1749. Lopinavir pharmacokinetic parameters were significantly lower for Regimens 2 and 3: GMR (90% CI) AUC(0-12), 0.74 (0.65-0.84) and 0.45 (0.40-0.51); C(max), 0.75 (0.66-0.85) and 0.54 (0.40-0.60); and C(trough), 0.74 (0.62-0.89) and 0.30 (0.25-0.36), respectively. All subjects taking the 400/100 and 200/150 mg twice daily doses, and 19 (86%) subjects taking 200/50 mg twice daily had lopinavir concentrations above the suggested minimum effective concentration of 1000 ng/mL. CONCLUSIONS: These pharmacokinetic data show that therapeutic plasma concentrations of lopinavir can be achieved with 200/150 mg of lopinavir/ritonavir twice daily (one Meltrex tablet and one 100 mg ritonavir capsule twice daily).

Efavirenz versus boosted atazanavir or zidovudine and abacavir in antiretroviral treatment-naive, HIV-infected subjects: week 48 data from the Altair study.

BACKGROUND: Antiretroviral therapy is complicated by drug interactions and contraindications. Novel regimens are needed. METHODS: This open label study randomly assigned treatment-naive, human immunodeficiency virus (HIV)-infected subjects to receive tenofovir-emtricitabine with efavirenz (Arm I), with ritonavir-boosted atazanavir (Arm II), or with zidovudine/abacavir (Arm III). Pair-wise comparisons of differences in time-weighted mean change from baseline plasma HIV-RNA to week 48 formed the primary analysis. Treatment arms were noninferior if the upper limit of the 95% confidence interval (CI) was <0.5 log(10) copies/mL. Secondary objectives included virologic, immunologic and safety end points. RESULTS: The intention-to-treat population comprised 322 patients (Arm I, n = 114; Arm II, n = 105; and Arm III, n = 103). Noninferiority for the primary end point was established. Analysis for superiority showed that Arm III was significantly less potent than Arm I (-0.20 log(10) copies/mL; 95% CI, -0.39 to -0.01 log(10) copies/mL; P = .038). The proportions of patients on each of Arm I (95%) and Arm II (96%) with <200 copies/mL were not different (P = .75), but the percentage of patients in Arm III with <200 copies/mL (82%) was significantly lower (P = .005). CD4+ cell counts did not differ. Serious adverse events were more frequent in Arm III (n = 30) than in Arm I or Arm II (n = 15 for each; P = .062). CONCLUSIONS: A novel quadruple nucleo(t)side combination demonstrated significantly less suppression of HIV replication, compared with the suppression demonstrated by standard antiretroviral therapy regimens, although it did meet the predetermined formal definition of noninferiority. Secondary analyses indicated statistically inferior virologic and safety performance. Efavirenz and ritonavir-boosted atazanavir arms were equivalent in viral suppression and safety.

Does choice of combination antiretroviral therapy (cART) alter changes in cerebral function testing after 48 weeks in treatment-naive, HIV-1-infected individuals commencing cART? A randomized, controlled study.

BACKGROUND: Neurocognitive impairment remains prevalent, despite combination antiretroviral therapy (cART). Differences between changes in cerebral function and alternative cARTs have not been prospectively assessed. METHODS: Treatment-naive, HIV-1-infected individuals randomly allocated to commence cART (tenofovir-emtricitabine plus either efavirenz [arm 1], atazanavir-ritonavir [arm 2], or zidovudine-abacavir [arm 3]) were eligible. Cerebral function tests included neurocognitive testing and assessment of cerebral metabolites using proton magnetic resonance spectroscopy in several anatomical voxels, including right frontal white matter and right basal ganglia, at baseline and after 48 weeks. N-acetylaspartate-to-creatine (NAA/Cr) ratios were calculated. Both the differences between changes in neurocognitive function and NAA/Cr ratios over 48 weeks and the study arms (arm 1 vs arm 2; arm 1 vs arm 3) were assessed. RESULTS: Thirty subjects completed study procedures (9, 9, and 12 subjects in arms 1, 2, and 3, respectively). Mean CD4+ cell counts (+/- standard deviation) were 218 +/- 87 cells/microL at baseline and 342 +/- 145 cells/microL at week 48. The mean plasma HIV-1 RNA level was <50 copies/mL for 28 of the 30 subjects at week 48. Over 48 weeks, greater improvements in identification reaction time (P = .04) and executive function (P = .02) were observed in arm 3, compared with arm 1 (0.03, -0.30, -0.50 log10 ms change in identification reaction time, in arms 1, 2, and 3, respectively). Increases in the NAA/Cr ratio were observed in all voxels (maximum 38% in right basal ganglia), with greater increases observed in arm 1 than in arm 2 (P = .03) in frontal white matter (30%, -7%, and 0% change in the NAA/Cr ratio, in arms 1, 2, and 3, respectively). CONCLUSIONS: To our knowledge, this is the first study to prospectively describe different changes in cerebral function testing parameters between different cARTs. Greater improvements in neuronal recovery (NAA/Cr ratio) were observed for recipients of tenofovir-emtricitabine plus efavirenz (arm 1), and greater improvements in neurocognitive function testing were observed for recipients of tenofovir-emtricitabine plus zidovudine-abacavir (arm 3).

An HIV-1 clade A/E DNA prime, recombinant fowlpox virus boost vaccine is safe, but non-immunogenic in a randomized phase I/IIa trial in Thai volunteers at low risk of HIV infection.

BACKGROUND: Previously demonstrated safe and highly immunogenic in non-human primates, this study assessed DNA (pHIS-HIV-AE) prime, recombinant fowlpox (rFPV-HIV-AE) boost vaccines in humans. RESULTS: Eight participants (6 active vaccine, 2 placebo) received all vaccinations; local and systemic reactions were mild to moderate. The percentage CD4(+) and CD8(+) T cells responding to HIV-1 Gag antigens by ICS (mean ± SD) was 0.16 ± 0.12 and 0.10 ± 0.12 for active and 0.01 ± 0.01 and 0.00 ± 0.00 for placebo vaccine respectively. The percentage of T cells responding did not reach pre-defined thresholds to be considered positive responses. Consequently, the Data Safety Monitoring Board recommended cessation of further recruitment. Existing volunteers were followed to 52 weeks. METHODS: Vectors expressing homologous HIV-1 clade A/E gag, pol, env and regulatory genes or matched placebo were administered intramuscularly at weeks 0, 4, 8 (6 mg pHIS-HIV-AE) and week 12 (3.0 x 10(8) pfu rFPV-HIV-AE) in this randomized, double-blind, placebo-controlled phase I/IIa study in healthy Thai adults at low risk of HIV infection. Immunogenicity was determined by interferon-gamma and IL-2 expression using intracellular cytokine staining assay (ICS), 13 weeks after randomization. Interim analysis was performed when eight volunteers reached 16 weeks follow-up. CONCLUSIONS: Vaccine candidates were generally well tolerated, but showed limited immunogenicity. Better vaccines and delivery systems are required.

Changes in plasma lipidome following initiation of antiretroviral therapy.

INTRODUCTION: HIV and antiretroviral therapy (ART) have been associated with increased cardiovascular disease and important changes in lipid metabolism. Advances in mass-spectrometry technology allow for the detailed assessment of individual lipid species which may illuminate the mechanisms underlying increased cardiovascular risk. We describe the change in plasma lipidome with initiation of antiretroviral therapy and compare these by regimen. METHODS: Plasma lipid profiling (by electrospray isonisation-tandem mass spectrometry) was performed on ARV-naive HIV positive participants randomised to one of three regimens; tenofovir/emtricitabine with efavirenz, ritonavir-boosted atazanavir (atazanavir/r) or zidovudine/abacavir. Participants (n = 115) who remained on their randomised regimen with complete samples available at baseline, week 12 and 48 were included. 306 lipid species from 22 lipid classes were analysed. RESULTS: Initiation of ART led to significant changes in lipidome which were partly dependent on the randomised regimen received. This led to significant differences in 72 lipid species and 7 classes (cholesterol ester, free cholesterol, phosphatidylcholine, GM3 ganglioside, trihexosylceramide, monohexosylceramide, and ceramides) by arm at week 48. Consistently higher lipid concentrations were seen with efavirenz compared with atazanavir/r or zidovudine/abacavir. Twelve of the lipid species and two lipid classes (cholesterol esters and ceramides) that were significantly increased in the efavirenz arm compared with the atazanavir/r or zidovudine/abacavir arms have previously been associated with future cardiovascular events in HIV positive patients. Change in HIV viral load was predictive of change in 3 lipid species. CONCLUSIONS: Initiation of ART lead to significant changes in the plasma lipidome that were greatest in those receiving efavirenz.

A randomized, placebo-controlled phase I trial of DNA prime, recombinant fowlpox virus boost prophylactic vaccine for HIV-1.

An HIV-vaccine consisting of a DNA prime, recombinant fowlpox virus (rFPV) boost was evaluated in a double-blind placebo controlled trial. One milligram of pHIS-HIV-B expressing mutated gag, pol, env, vpu, tat and rev was administered at weeks 0 and 4 boosted by 5 x 10(7) pfu rFPV-HIV-B expressing gag/pol at week 8. The vaccine regimen was safe, but there was no difference between vaccine (n = 18) and placebo recipients (n = 6) for Gag or Pol-specific T-cell immune responses at week 9.

Evaluation of the HIV lipodystrophy case definition in a placebo-controlled, 144-week study in antiretroviral-naive adults.

OBJECTIVE: To compare three versions of the objective HIV-associated lipodystrophy (HIVLD) case definition (LDCD) and derived severity scale to spontaneous clinical LD assessment in adults initiating antiretroviral therapy. DESIGN AND MAIN OUTCOME MEASURES: The LDCD versions were the 'primary' LDCD [which includes dual-energy X-ray absorptiometry (DXA) and computerized tomography (CT)], a simpler 'central' LDCD that omits CT data, and a simpler but probably less accurate 'non-imaging' LDCD. Physician LD assessments were passively reported. Two of the 10 parameters in the primary LDCD were not collected and were imputed. Setting, participants and interventions: Retrospective analysis of a randomized, placebo-controlled, 144-week study of tenofovir DF or stavudine (d4T) in 600 antiretroviral-naive adults. RESULTS: Central LDCD and clinical assessment diagnosed LD in 27% and 19% of d4T recipients at week 144, respectively (P < 0.001), and 3% and 3% of tenofovir DF recipients, respectively (P = 0.248). The central LDCD performed at least as well as the primary LDCD; both were more sensitive than the non-imaging model. There was poor concordance between clinical and LDCD-based diagnosis (kappa 0.02-0.20); most clinical cases did not fulfill any LDCD. Using the central LDCD, most LD was grade 1; 6% of d4T recipients and no tenofovir DF recipient had grade 3-4 LD at week 144 (P = 0.007). Independent risk factors for LD using the central LDCD were d4T, increasing age, female sex and higher baseline triglycerides, whereas clinical assessment consistently identified only d4T. The LDCD score was more sensitive than DXA for assessing LD severity. CONCLUSIONS: In this prospective study of a first antiretroviral regimen, the LDCD was more sensitive for LD diagnosis and identified more lipodystrophy risk factors than spontaneous clinical assessment or DXA, and also objectively quantified LD severity. The central LDCD should make objective LD assessment cheaper and simpler. Spontaneous clinical LD assessment of is of limited value, even in placebo-controlled trials.

Comprehensive Pharmacokinetic, Pharmacodynamic and Pharmacogenetic Evaluation of Once-Daily Efavirenz 400 and 600 mg in Treatment-Naïve HIV-Infected Patients at 96 Weeks: Results of the ENCORE1 Study.

BACKGROUND: ENCORE1 demonstrated non-inferiority of daily efavirenz 400 mg (EFV400) versus 600 mg (EFV600) to 96 weeks in treatment-naïve, HIV-infected adults but concerns regarding lower EFV400 concentrations remained. Therefore, relationships between EFV pharmacokinetics (PK) and key genetic polymorphisms with 96-week efficacy and safety were investigated. METHODS: Relationships between EFV PK parameters and single nucleotide polymorphisms (SNP; CYP2B6, CYP2A6, CYP3A4, NR1I3, NR1I2, ABCB1) with plasma HIV-RNA (pVL) <200 copies/mL and EFV discontinuation and adverse events at 96 weeks were explored. Receiver operating characteristic curve analysis evaluated the predictability of mid-dose interval (C12) cutoffs and 96-week pVL. RESULTS: A total of 606 patients (32 % female; 37 % African, 33 % Asian; n = 311 EFV400, n = 295 EFV600) were included. EFV PK parameters, including C12, were not associated with pVL <200 copies/mL at 96 weeks (odds ratio [OR] 5.25, 95 % confidence interval [CI] 0.41-67.90, p = 0.204). Lower risk of CNS-related adverse events was associated with CYP2B6 983TC/CC (OR 0.35, 95 % CI 0.15-0.81, p = 0.015) and higher risk was associated with CYP2B6 15582CT/TT and ABCB1 3435TT (OR 1.46, 95 % CI 1.02-2.09, p = 0.040; OR 2.31, 95 % CI 1.33-4.02, p = 0.003, respectively). Discontinuation due to adverse events (clinician decision) was independently associated with dose (OR 2.54, 95 % CI 1.19-5.43, p = 0.016). C12 between 0.47 and 0.76 mg/L provided sensitivity/specificity >90 % (100 %/92.3 to 98.9 %/92.3 %) for achieving pVL <200 copies/mL at 96 weeks. CONCLUSIONS: A higher rate of EFV-related adverse events and discontinuations due to these events for EFV600 were not driven by polymorphisms assessed. Although a single threshold concentration associated with HIV suppression may be clinically useful, it was not viable for ENCORE1. Implementation of EFV400 would improve toxicity management whilst still maintaining good efficacy.

Assessing site performance in the Altair study, a multinational clinical trial.

BACKGROUND: Reviewing clinical trial site performance identifies strategies to control outcomes. Performance across 5 geographical regions (36 sites across Asia, Australia, Europe, North America and Latin America) was investigated in a study that randomised 322 HIV-infected individuals. METHODS: Regional performance was compared using descriptive analysis for time to site opening, recruitment, quality of data and laboratory samples. Follow-up consisted of 10 visits (96 weeks), electronic data collection (EDC) within 7 days of a visit and serious adverse events (SAEs) reported within 24 hours of site awareness. RESULTS: Median days to site opening was 250 (188 to 266), ranging from 177 (158 to 200) (Australia) to 265 (205 to 270) (Europe). Median days to ethics and regulatory approval was 182 (120 to 241) and 218 (182 to 341) days, respectively. Within regions, time to approval ranged from 187 (91 to 205) days (Australia) to 276 (175 to 384) days (Europe). Time to first randomisation ranged from 282 (250 to 313) days (Australia) to 426 (420 to 433) days (North America). Recruitment was lower than forecasted in Asia, Australia, Europe and North America at 89%, 77%, 91% and 43%, respectively. The converse was true in Latin America where despite ethics, regulatory and contractual delays, recruitment was 104% of predicted. Median days to EDC was 7 (3 to 16), ranging from 3 (1 to 16) (Asia) to 13 (8 to 14) days (North America). Median days for initial SAE submission to sponsor was 6 (2 to 20), ranging from 4 (2 to 18) (Latin America) to 24 (5 to 46) days (Australia). Sites took longer to submit final reports, overall median of 28 (7 to 91) days, ranging from 7 days (Australia) to 67 (23 to 103) days (Europe). CONCLUSIONS: Population availability and time to ethics and regulatory approvals influence recruitment; therefore accurate feasibility assessments are critical to site selection. Time to ethics and regulatory approval may not limit site inclusion if compensated by rapid recruitment. Identifying potential delays and methods for reduction can decrease time and costs for sponsors. TRIAL REGISTRATION: Clinical Trials.Gov identifier: NCT00335322. Date of registration: 8 June 2006.

Differences in the direction of change of cerebral function parameters are evident over three years in HIV-infected individuals electively commencing initial cART.

BACKGROUND: Changes in cerebral metabolite ratios (CMR) measured on 1H-MRS and changes in cognitive function (CF) are described in subjects commencing combination antiretroviral therapy (cART), although the dynamics of such changes are poorly understood. METHODS: Neuroasymptomatic, HIV-infected subjects electively commencing cART were eligible. CMR were assessed in three anatomical voxels and CF assessed at baseline, week 48 and week 144. Overall differences in absolute change in CMRs and CF parameters between 0-48 and 48-144 weeks were assessed. RESULTS: Twenty-two subjects completed study procedures. Plasma HIV-RNA was <50 copies/mL in all at week 48 and in all, but two subjects at week 144. In general, between weeks 0-48 a rise in N-acetyl-aspartate(NAA)/Creatine(Cr) ratio and a decline in myo-Inositol(mI)/Cr ratio were observed. Between weeks 48-144, small rises in NAA/Cr ratio were observed in two anatomical voxels, whereas a rise in mI/Cr ratio was observed in all anatomical locations (0.31 (0.66) and -0.27 (1.35) between weeks 0-48 and 0.13 (0.91) and 1.13 (1.71) between weeks 48-144 for absolute changes in NAA/Cr and mI/Cr (SD) in frontal-grey voxel, respectively). Global CF score improved between weeks 0-48 and then declined between weeks 48-144 (0.63 (1.16) and -0.63 (0.1.41) for mean absolute change (SD) between weeks 0-48 and weeks 48-144, respectively). CONCLUSIONS: The direction of change of cerebral function parameters differs over time in HIV-infected subjects commencing cART, highlighting the need for long-term follow-up in such studies. The changes we have observed between weeks 48-144 may represent the initial development of cerebral toxicities from cART.

Efficacy and safety of efavirenz 400 mg daily versus 600 mg daily: 96-week data from the randomised, double-blind, placebo-controlled, non-inferiority ENCORE1 study.

BACKGROUND: The week 48 primary analysis of the ENCORE1 trial established the virological non-inferiority and safety of efavirenz 400 mg compared with the standard 600 mg dose, combined with tenofovir and emtricitabine, as first-line HIV therapy. This 96-week follow-up of the trial assesses the durability of efficacy and safety of this treatment over 96 weeks. METHODS: ENCORE1 was a double-blind, placebo-controlled, non-inferiority trial done at 38 clinical sites in 13 countries. HIV-infected adult patients (≥16 years of age) with no previous antiretroviral therapy, a CD4 cell count of 50-500 cells per µL, and plasma HIV-1 viral load of at least 1000 copies per mL were randomly assigned (1:1) by an electronic case report form to receive fixed-dose daily tenofovir 300 mg and emtricitabine 200 mg plus efavirenz either 400 mg daily or 600 mg daily. Participants, physicians, and all other trial staff were masked to treatment assignment. Randomisation was stratified by HIV-1 viral load at baseline (≤ or >100 000 copies per mL). The primary endpoint was the difference in the proportions of patients in the two treatment groups with a plasma HIV-1 viral load below 200 copies per mL at week 96. Treatment groups were deemed to be non-inferior if the lower limit of the 95% CI for the difference in viral load was above -10% by modified intention-to-treat analysis. Non-inferiority was assessed in the modified intention-to-treat, per-protocol, and non-completer=failure (NC=F) populations. Adverse events and serious adverse events were summarised by treatment group. This study is registered with ClinicalTrials.gov, number NCT01011413. FINDINGS: Between Aug 24, 2011, and March 19, 2012, 636 eligible participants were enrolled and randomly assigned to the two treatment groups (324 to efavirenz 400 mg and 312 to efavirenz 600 mg). The intention-to-treat population who received at least one dose of study drug comprised 630 patients: 321 in the efavirenz 400 mg group and 309 in the efavirenz 600 mg group. 585 patients (93%; 299 in the efavirenz 400 mg group and 286 in the 600 mg group) completed 96 weeks of follow-up. At 96 weeks, 289 (90·0%) of 321 patients in the efavirenz 400 mg group and 280 (90·6%) of 309 in the efavirenz 600 mg group had a plasma HIV-1 viral load less than 200 copies per mL (difference -0·6, 95% CI -5·2 to 4·0; p=0·72), which suggests continued non-inferiority of the lower efavirenz dose. Non-inferiority was recorded for thresholds of less than 50 and less than 400 copies per mL, irrespective of baseline plasma viral load. Adverse events were reported by 291 (91%) of 321 patients in the efavirenz 400 mg group and by 285 (92%) of 309 in the 600 mg group (p=0·48). The proportions of patients reporting an adverse event that was definitely or probably related to efavirenz were 126 (39%) for efavirenz 400 mg and 148 (48%) for efavirenz 600 mg (p=0·03). The number of patients who reported serious adverse events did not differ between the groups (p=0·20). INTERPRETATION: Our findings confirm that efavirenz 400 mg is non-inferior to the standard dose of 600 mg in combination with tenofovir and emtricitabine as initial HIV therapy over 96 weeks. Fewer efavirenz-related adverse events were reported with the 400 mg efavirenz dose than with the 600 mg dose. These findings support the routine use of efavirenz 400 mg. The coadministration of rifampicin and efavirenz 400 mg needs further investigation. FUNDING: Bill & Melinda Gates Foundation, and UNSW Australia.

Interleukin 12-augmented T cell proliferation of peripheral blood mononuclear cells from HIV-seropositive individuals is associated with interleukin 12 receptor beta 2 upregulation.

Interleukin 12 (IL-12) production is believed to be impaired in individuals with HIV infection and this impairment manifests early in disease, when the CD4(+) cell counts are within normal values. The reduced antigen-specific and mitogen-stimulated T cell-proliferative responses that occur in HIV infection can be corrected by the addition of recombinant human interleukin 12 (rhIL-12). As the IL-12 receptor (IL-12R) is central to the IL-12 signaling pathway, we examined whether the augmentation of antigen-specific proliferation of HIV(+) peripheral blood mononuclear cells (PBMCs) related to altered IL-12R expression. rhIL-12 augmented antigen-specific proliferation of HIV(+) PBMCs but not of HIV(-) PBMCs. Examination of resting PBMCs from HIV(+) and HIV(-) donors showed that neither of these populations expressed IL-12R beta 1 or IL-12R beta 2 chains on their cell surface as detected by flow cytometry. However, examination of mRNA showed that both IL-12R beta 1 and IL-12R beta 2 mRNAs were markedly reduced in HIV(+) PBMCs when compared with HIV(-) PBMCs. After mitogen activation there was an increase in IL-12R beta 1 expression on the cell surface of HIV(+) and HIV(-) PBMCs and this level was not altered by coculture with rhIL-12 or interferon gamma (IFN-gamma). However, coculture of phytohemagglutinin (PHA)-activated HIV(+) or HIV(-) PBMCs with rhIL-12 (but not IFN-gamma) increased IL-12R beta 2 expression on the cell surface of both populations. Examination at the message level showed a correction of IL-12R beta 1 to normal levels with activation that was further enhanced by rhIL-12 coculture for both the HIV(+) and HIV(-) PBMCs. However, although the level of IL-12R beta 2 for the HIV(+) PBMCs was normalized by PHA, rhIL-12 caused a further augmentation. This information provides a strong link between IL-12R upregulation, and the significant improvement in antigen-specific HIV-proliferative responses seen with the addition of rhIL-12. It also reveals that the dysfunction in IL-12R expression seen in cells from HIV(+) patients occurs at the transcriptional level. In addition, we provide further evidence that IL-12R beta 1 and IL-12R beta 2 regulation in human PBMCs is independent of IFN-gamma.

Practical applications of the HIV lipodystrophy case definition.

Diagnosis of HIV-associated lipodystrophy (LD) has been limited by the absence of a validated case definition and the frequent lack of objective body composition measures. An international, objective, case-control study recruited HIV-infected, adult outpatients free of active AIDS, and a case definition model for LD was developed. The relative merits and limitations of this definition as a practical tool for the long-term monitoring of a patient's LD status over the duration of clinical treatment are discussed.

Cerebrospinal-fluid exposure of efavirenz and its major metabolites when dosed at 400 and 600 mg once daily; a randomized controlled trial.

INTRODUCTION: The optimal penetration of antiretroviral agents into central nervous system (CNS) may be a balance between providing adequate drug exposure to inhibit HIV-replication whilst avoiding concentrations associated with toxicities. METHODS: Cerebrospinal-fluid (CSF) exposure of efavirenz and metabolites 7-hydroxy (7OH-) and 8OH-efavirenz were assessed after at least 12 weeks of antiretroviral therapy in HIV-infected subjects randomized to commence antiretroviral regimens containing efavirenz at either 400 mg or 600 mg once daily. Clinical, pharmacokinetic and pharmacogenomic factors associated with CSF efavirenz and its metabolite concentrations were assessed. RESULTS: Of 28 subjects who completed all study procedures (14/14 on efavirenz 400 mg/600 mg), CSF HIV RNA was below 20 copies/mL in all at the time of examination. Concentrations of efavirenz and 7OH-efavirenz in the CSF were slightly lower when dosed at 400 mg versus 600 mg, although this was not statistically significant. A different trend was observed regarding 8OH-efavirenz concentrations where CSF exposure was slightly increased in the 400 mg efavirenz arm (see Table 1). Efavirenz concentration in the CSF was above 0.51 ng/mL (proposed CSF IC50 for WT virus) in all subjects and 8OH-efavirenz concentration in the CSF was above 3.3 ng/mL (a proposed toxicity threshold, reference) in 11/14 and 7/14 subjects randomized to the 400 mg and 600 mg doses of efavirenz, respectively. Whilst CSF efavirenz concentration was significantly associated with plasma concentration (P<0.001) and CYP2B6 genotype (CSF efavirenz GG to GT/TT GM ratio 0.56, 90% CI 0.42-0.74), CSF 8OH-efavirenz concentration was not (P=0.242 for association with plasma concentration and CSF 8OH-efavirenz GG to GT/TT GM ratio 1.52, 90% CI 0.97-2.36). Lastly, CSF 8OH-efavirenz concentration was associated with efavirenz symptom questionnaire results at one year (Spearman's correlation 0.13, P=0.05). CONCLUSIONS: With both doses of efavirenz studied, CSF concentrations were considered adequate to inhibit HIV-replication, although concentrations of 8OH-efavirenz were greater than that reportedly associated with neuronal toxicity. CSF exposure of 8OH-efavirenz was not dependent on plasma exposure and we postulate may be subject to saturable pharmacokinetic effects.