Karin L. Klingman

Initiation of Antiretroviral Therapy in Early Asymptomatic HIV Infection

BACKGROUND Data from randomized trials are lacking on the benefits and risks of initiating antiretroviral therapy in patients with asymptomatic human immunodeficiency virus (HIV) infection who have a CD4+ count of more than 350 cells per cubic millimeter. METHODS We randomly assigned HIV-positive adults who had a CD4+ count of more than 500 cells per cubic millimeter to start antiretroviral therapy immediately (immediate-initiation group) or to defer it until the CD4+ count decreased to 350 cells per cubic millimeter or until the development of the acquired immunodeficiency syndrome (AIDS) or another condition that dictated the use of antiretroviral therapy (deferred-initiation group). The primary composite end point was any serious AIDS-related event, serious non-AIDS-related event, or death from any cause. RESULTS A total of 4685 patients were followed for a mean of 3.0 years. At study entry, the median HIV viral load was 12,759 copies per milliliter, and the median CD4+ count was 651 cells per cubic millimeter. On May 15, 2015, on the basis of an interim analysis, the data and safety monitoring board determined that the study question had been answered and recommended that patients in the deferred-initiation group be offered antiretroviral therapy. The primary end point occurred in 42 patients in the immediate-initiation group (1.8%; 0.60 events per 100 person-years), as compared with 96 patients in the deferred-initiation group (4.1%; 1.38 events per 100 person-years), for a hazard ratio of 0.43 (95% confidence interval [CI], 0.30 to 0.62; P<0.001). Hazard ratios for serious AIDS-related and serious non-AIDS-related events were 0.28 (95% CI, 0.15 to 0.50; P<0.001) and 0.61 (95% CI, 0.38 to 0.97; P=0.04), respectively. More than two thirds of the primary end points (68%) occurred in patients with a CD4+ count of more than 500 cells per cubic millimeter. The risks of a grade 4 event were similar in the two groups, as were the risks of unscheduled hospital admissions. CONCLUSIONS The initiation of antiretroviral therapy in HIV-positive adults with a CD4+ count of more than 500 cells per cubic millimeter provided net benefits over starting such therapy in patients after the CD4+ count had declined to 350 cells per cubic millimeter. (Funded by the National Institute of Allergy and Infectious Diseases and others; START ClinicalTrials.gov number, NCT00867048.).

Class-sparing regimens for initial treatment of HIV-1 infection.

BACKGROUND The use of either efavirenz or lopinavir-ritonavir plus two nucleoside reverse-transcriptase inhibitors (NRTIs) is recommended for initial therapy for patients with human immunodeficiency virus type 1 (HIV-1) infection, but which of the two regimens has greater efficacy is not known. The alternative regimen of lopinavir-ritonavir plus efavirenz may prevent toxic effects associated with NRTIs. METHODS In an open-label study, we compared three regimens for initial therapy: efavirenz plus two NRTIs (efavirenz group), lopinavir-ritonavir plus two NRTIs (lopinavir-ritonavir group), and lopinavir-ritonavir plus efavirenz (NRTI-sparing group). We randomly assigned 757 patients with a median CD4 count of 191 cells per cubic millimeter and a median HIV-1 RNA level of 4.8 log10 copies per milliliter to the three groups. RESULTS At a median follow-up of 112 weeks, the time to virologic failure was longer in the efavirenz group than in the lopinavir-ritonavir group (P=0.006) but was not significantly different in the NRTI-sparing group from the time in either of the other two groups. At week 96, the proportion of patients with fewer than 50 copies of plasma HIV-1 RNA per milliliter was 89% in the efavirenz group, 77% in the lopinavir-ritonavir group, and 83% in the NRTI-sparing group (P=0.003 for the comparison between the efavirenz group and the lopinavir-ritonavir group). The groups did not differ significantly in the time to discontinuation because of toxic effects. At virologic failure, antiretroviral resistance mutations were more frequent in the NRTI-sparing group than in the other two groups. CONCLUSIONS Virologic failure was less likely in the efavirenz group than in the lopinavir-ritonavir group. The virologic efficacy of the NRTI-sparing regimen was similar to that of the efavirenz regimen but was more likely to be associated with drug resistance. (ClinicalTrials.gov number, NCT00050895 [ClinicalTrials.gov].).

Metabolic Outcomes in a Randomized Trial of Nucleoside, Nonnucleoside and Protease Inhibitor-Sparing Regimens for Initial HIV Treatment

Background:The metabolic effects of initial therapy for HIV-1 infection are important determinants of regimen selection. Methods:Open-label study in 753 subjects randomized equally to efavirenz or lopinavir/ritonavir(r) plus two nucleoside reverse-transcriptase inhibitor (NRTI) vs. the NRTI-sparing regimen of lopinavir/r plus efavirenz. Zidovudine, stavudine, or tenofovir with lamivudine was selected prior to randomization. Metabolic outcomes through 96 weeks were lipoatrophy, defined as at least 20% loss in extremity fat, and fasting serum lipids. Results:Lipoatrophy by dual-energy X-ray absorptiometry at week 96 occurred in 32% [95% confidence interval (CI) 25–39%] of subjects in the efavirenz plus two NRTIs arm, 17% (95% CI 12–24) in the lopinavir/r plus two NRTIs arm, and 9% (95% CI 5–14) in the NRTI-sparing arm (P ≤ 0.023 for all comparisons). Varying the definition of lipoatrophy (≥10 to ≥40% fat loss) and correction for baseline risk factors did not affect the significant difference in lipoatrophy between the NRTI-containing regimens. Lipoatrophy was most frequent with stavudine-containing regimens and least frequent with tenofovir-containing regimens (P < 0.001), which were not significantly different from the NRTI-sparing regimen. Total cholesterol increases at week 96 were greatest in the NRTI-sparing arm (median +57 mg/dl) compared with the other two arms (+32–33 mg/dl; P < 0.001). Use of lipid-lowering agents was more common (25 vs. 11–13%) in the NRTI-sparing arm. Conclusion:Lipoatrophy was more frequent with efavirenz than lopinavir/r when combined with stavudine or zidovudine, and less frequent when either drug was combined with tenofovir. Lipoatrophy was least frequent with the NRTI-sparing regimen, but this benefit was offset by greater cholesterol elevations and the need for lipid-lowering agents.

Simultaneous Respiratory Tract Colonization by Multiple Strains of Nontypeable Haemophilus influenzae in Chronic Obstructive Pulmonary Disease: Implications for Antibiotic Therapy

Nontypeable Haemophilus influenzae often causes exacerbations of chronic obstructive pulmonary disease (COPD), and these exacerbations are frequently treated with oral antibiotics. The goals of this study were to determine the frequency of the simultaneous presence of multiple strains of H. influenzae in sputum and to measure the MICs of antibiotics for the isolates. In a prospective study, adults with COPD were seen monthly. Sputum cultures were obtained, and individual colonies were subjected to genomic DNA typing and MIC determinations. Multiple strains of H. influenzae were present simultaneously in the sputum of 26.3% of adults with COPD. In 64.5% of these, MICs of >/=1 antibiotic varied by >/=4-fold among the strains. Therefore, multiple strains of H. influenzae are frequently present simultaneously in the sputum of adults with COPD, and the antimicrobial susceptibility of different strains in the same sputum sometimes differs.

Multiple-Dose Escalation Study of the Safety, Pharmacokinetics, and Biologic Activity of Oral AMD070, a Selective CXCR4 Receptor Inhibitor, in Human Subjects

ABSTRACT AMD070 is an oral CXCR4 antagonist with in vitro activity against X4-tropic human immunodeficiency virus type 1. Thirty fasting healthy male volunteers received oral doses of AMD070 ranging from a single 50-mg dose to seven 400-mg doses given every 12 h (q12h). Nine subjects received a 200-mg dose during fasting and prior to a meal. Subjects were monitored for safety and pharmacokinetics. AMD070 was well tolerated, without serious adverse events. Transient headaches (13 subjects) and neurocognitive (8 subjects) and gastrointestinal (7 subjects) symptoms were the most common complaints. Seven subjects had sinus tachycardia, and two were symptomatic. AMD070 plasma concentrations peaked 1 to 2 h after patient dosing. The estimated terminal half-life ranged from 11.2 to 15.9 h among cohorts. Dose proportionality was not demonstrated. Less than 1% of the drug appeared unchanged in the urine. Food reduced the maximum concentration of drug in serum and the area under the concentration-time curve from 0 to 24 h by 70% and 56%, respectively (P ≤ 0.01). A dose-dependent elevation of white blood cells (WBC) demonstrated a maximum twofold increase over baseline (95% confidence interval, 2.0- to 2.1-fold) in an Emax model. In healthy volunteers, AMD070 was well tolerated and demonstrated mixed-order pharmacokinetics, and food reduced drug exposure. AMD070 induced a dose-related elevation of WBC which was attributed to CXCR4 blockade. Using leukocytosis as a surrogate marker for CXCR4 inhibition, this dose-response relationship suggests that the doses used in this study were active in vivo, though not maximal, throughout the dosing interval. Trough concentrations with the 400-mg dose q12h exceeded the antiviral in vitro 90% effective concentration of AMD070.

Combining fosamprenavir with lopinavir/ritonavir substantially reduces amprenavir and lopinavir exposure: ACTG protocol A5143 results

Objective:To evaluate fosamprenavir/lopinavir (LPV)/ritonavir (RTV), fosamprenavir/RTV, or LPV/RTV in antiretroviral treatment-experienced patients. Lack of drug interaction data prompted a pharmacokinetic substudy to minimize subject risk. Design:Multi-center, open-label, selectively randomized, steady-state pharmacokinetic study in HIV-infected subjects. Methods:A planned independent interim review occurred after at least eight subjects were randomized to each arm. Subjects received twice daily LPV/RTV 400/100 mg (arm A; n = 8); fosamprenavir/RTV 700/100 mg (arm B; n = 8) or LPV/RTV/fosamprenavir 400/100/700 mg (arm C; n = 17). Plasma samples were collected over 12 h between study weeks 2 and 4. Pharmacokinetic parameters were compared based on a one-sided t-test on log-transformed data with a Peto stopping boundary (P < 0.001). Results:Amprenavir mean area under the curve over 12 h (AUC0–12 h) and concentration at 12 h (C12 h) (μg/ml) were, respectively, 42.7 μg × h/ml (range, 33.1–55.1) and 2.4 μg/ml (range, 1.4–3.2) in arm B and 17.4 μg × h/ml (range, 4.6–41.3) and 0.9 μg/ml (range, 0.2–2.7) in arm C: geometric mean ratio (GMR) arm C:B was 0.36 [99.9% upper confidence boundary (UCB), 0.64] and 0.31 (99.9% h UCB, 0.61), respectively (P ≤ 0.0001). Lopinavir AUC0–12 h and C12 h were, respectively, 95.3 μg × h/ml (range, 60.3–119.3) and 6.3 μg/ml (range, 2.2–9.2) in arm A and 54.4 μg × h/ml (range, 23.5–112.2) and 3.0 μg/ml (range, 0.4–7.9) in arm C: GMR arm C:A of 0.52 (99.9% UCB, 0.89) and 0.39 (99.9% UCB, 0.98), respectively (P ≤ 0.0008). Ritonavir exposure was not significantly different between arms. Conclusion:APV and LPV exposures are significantly reduced using LPV/RTV/fosamprenavir, possibly increasing the risk of virologic failure. Consequently, A5143 was closed to enrollment.

Plasma HIV-1 RNA Dynamics in Antiretroviral-Naive Subjects Receiving either Triple-Nucleoside or Efavirenz-Containing Regimens: ACTG A5166s

OBJECTIVE We sought to compare clearance rates of plasma human immunodeficiency virus type 1 (HIV-1) RNA in men and women starting triple-nucleoside-based versus efavirenz (EFV)-based regimens. METHODS First- and second-phase decay rates of plasma HIV-1 were compared in men and women initiating a triple nucleoside reverse-transcriptase inhibitor (NRTI) regimen versus regimens that included EFV plus an NRTI. Subjects (n=64) were randomized to receive zidovudine/lamivudine/abacavir (triple-nucleoside regimen), zidovudine/lamivudine plus EFV (3-drug EFV regimen) or zidovudine/lamivudine/abacavir plus EFV (4-drug EFV regimen). Plasma HIV-1 RNA levels were fitted to a biexponential viral-dynamics model using a nonlinear mixed-effects model. Nonparametric Wilcoxon tests compared empirical Bayes estimates of first- and second-phase viral decay rates between treatment arms and sex. RESULTS Median first-phase viral decay rates were significantly faster in subjects receiving the 3-drug EFV regimen (0.67/day), compared with those receiving the triple-nucleoside regimen (0.56/day; P=.02). The second-phase viral decay rate was also faster in the 3-drug EFV group than in the triple-nucleoside group (P=.09). Decay rates in the 4-drug EFV group were intermediate. Viral decay rates were not significantly different in men and women. CONCLUSIONS Faster initial viral decay in subjects randomized to a 3-drug EFV-based regimen corresponded to the overall superior efficacy of that regimen. Viral decay rates did not differ by sex.

Why START? Reflections that led to the conduct of this large long-term strategic HIV trial

This monograph describes a cohort of 4685 HIV-positive persons, most of whom were recently infected, who volunteered to dedicate several years to being participants in a research study that addresses the question of when antiretroviral therapy (ART) should be initiated. Should it be started early after HIV infection occurs, or should it be deferred until the infection has started to impair immune function but before the risk of AIDS increases? There has been consensus based on robust data for many years that ART should be initiated following the development of AIDS. Also, within the past 6 to 7 years, data from randomized trials [1–3] and observational studies [4–7] emerged that supported the initiation of ART when the CD4 cell count declined to < 350 cells/μL among asymptomatic individuals. It has been hotly debated whether the clinical benefits of initiating ART at a CD4 cell count > 500 cells/ μL, compared with deferring ART until the CD4 cell count decreases to 350 cells/μL, as is being tested in the Strategic Timing of AntiRetroviral Treatment (START) study, outweigh the risks [8–10]. The debate is lively because the data available are not optimal. The fact that 4685 persons from 215 clinics in 35 countries volunteered to be randomized in START reflects the considerable uncertainty that many individuals with HIV infection and investigators around the world have about the answer to the question being addressed by START.

Lopinavir/ritonavir monotherapy after virologic failure of first-line antiretroviral therapy in resource-limited settings.

Objective:To evaluate virologic response rates of lopinavir/ritonavir (LPV/r) monotherapy as second-line antiretroviral treatment (ART) among adults in resource-limited settings (RLSs). Design:An open-label pilot study of LPV/r monotherapy in participants on first-line nonnucleoside reverse transcriptase inhibitor three-drug combination ART with plasma HIV-1 RNA 1000–200 000 copies/ml. Methods:Participants were recruited from five sites in Africa and Asia within the AIDS Clinical Trials Group (ACTG) network. All participants received LPV/r 400/100 mg twice daily. The primary endpoint was remaining on LPV/r monotherapy without virologic failure at week 24. Participants with virologic failure were offered addition of emtricitabine and tenofovir (FTC/TDF) to LPV/r. Results:Mutations associated with drug resistance were encountered in nearly all individuals screened for the study. One hundred and twenty-three participants were enrolled, and 122 completed 24 weeks on study. A high proportion remained on LPV/r monotherapy without virologic failure at 24 weeks (87%). Archived samples with HIV-1 RNA levels less than 400 copies/ml at week 24 (n = 102) underwent ultrasensitive assay. Of these individuals, 62 had levels less than 40 copies/ml and 30 had levels 40–200 copies/ml. Fifteen individuals experienced virologic failure, among whom 11 had resistance assessed and two had emergent protease inhibitor mutations. Thirteen individuals with virologic failure added FTC/TDF and one individual added FTC/TDF without virologic failure. At study week 48, 11 of 14 adding FTC/TDF had HIV-1 RNA levels less than 400 copies/ml. Conclusion:In this pilot study conducted in diverse RLS, LPV/r monotherapy as second-line ART demonstrated promising activity.

Contraceptive Efficacy of Oral and Transdermal Hormones When Co-Administered With Protease Inhibitors in HIV-1―Infected Women: Pharmacokinetic Results of ACTG Trial A5188

Background:Pharmacokinetic (PK) interactions between lopinavir/ritonavir (LPV/r) and transdermally delivered ethinyl estradiol (EE) and norelgestromin (NGMN) are unknown. Methods:Using a standard noncompartmental PK analysis, we compared EE area under the time-concentration curve (AUC) and NGMN AUC during transdermal contraceptive patch administration in HIV-1-infected women on stable LPV/r to a control group of women not on highly active antiretroviral therapy (HAART). In addition, EE AUC after a single dose of a combination oral contraceptive pill including EE and norethindrone was measured before patch placement and was compared with patch EE AUC in both groups. Contraceptive effects on LPV/r PKs were estimated by measuring LPV/r AUC at baseline and during week 3 of patch administration. Results:Eight women on LPV/r, and 24 women in the control group were enrolled. Patch EE median AUC0−168 h was 45% lower at 6010.36 pg·h·mL−1 in those on LPV/r versus 10911.42 pg·h·mL−1 in those on no HAART (P = 0.064). Pill EE median AUC0−48 hours was similarly 55% lower at 344.67 pg·h·mL−1 in those on LPV/r versus 765.38 pg·h·mL−1 in those on no HAART (P = 0.003). Patch NGMN AUC0−168 h however, was 138.39 ng·h·mL−1, 83% higher in the LPV/r group compared with the control AUC of 75.63 ng·h·mL−1 (P = 0.036). After 3 weeks on the patch, LPV AUC0−8 h decreased by 19%, (P = 0.156). Conclusions:Although PKs of contraceptive EE and NGMN are significantly altered with LPV/r, the contraceptive efficacy of the patch is likely to be maintained. Larger studies are indicated to fully assess contraceptive efficacy versus risks of the transdermal contraceptive patch when co-administered with protease inhibitors.