A randomized trial of 2 different 4-drug antiretroviral regimens versus a 3-drug regimen, in advanced human immunodeficiency virus disease

Fusing trial data for treatment comparisons: Single vs multi-span bridging

While randomized controlled trials (RCTs) are critical for establishing the efficacy of new therapies, there are limitations regarding what comparisons can be made directly from trial data. RCTs are limited to a small number of comparator arms and often compare a new therapeutic to a standard of care which has already proven efficacious. It is sometimes of interest to estimate the efficacy of the new therapy relative to a treatment that was not evaluated in the same trial, such as a placebo or an alternative therapy that was evaluated in a different trial. Such dual-study comparisons are challenging because of potential differences between trial populations that can affect the outcome. In this article, two bridging estimators are considered that allow for comparisons of treatments evaluated in different trials, accounting for measured differences in trial populations. A "multi-span" estimator leverages a shared arm between two trials, while a "single-span" estimator does not require a shared arm. A diagnostic statistic that compares the outcome in the standardized shared arms is provided. The two estimators are compared in simulations, where both estimators demonstrate minimal empirical bias and nominal confidence interval coverage when the identification assumptions are met. The estimators are applied to data from the AIDS Clinical Trials Group 320 and 388 to compare the efficacy of two-drug vs four-drug antiretroviral therapy on CD4 cell counts among persons with advanced HIV. The single-span approach requires weaker identification assumptions and was more efficient in simulations and the application.

IFNL4 Genotype Does Not Associate with CD4 T-Cell Recovery in People Living with Human Immunodeficiency Virus

Immune non-responders (INRs) are people with HIV infection who fail to restore their CD4 T-cell counts in spite of prolonged virologic suppression, a condition associated with higher rates of all-cause mortality. The mechanisms of immune non-response are not entirely clear. We used existing clinical and genetic data from AIDS Clinical Trials Group clinical trials to ask whether an IFNL4 single-nucleotide polymorphism, shown to be associated with outcomes for other infectious diseases, correlated with immune non-response for HIV. Analysis of data from 426 participants with clearly defined CD4 T-cell recovery phenotypes, including 88 INRs with CD4 < 200 cells/mm³ after 2 years of suppressive antiretroviral therapy, did not identify an association of IFNL4 genotype with immune non-response. Thus, the IFNL4 genotype is unlikely to influence immunologic recovery.

Presence of asymptomatic cytomegalovirus and Epstein--Barr virus DNA in blood of persons with HIV starting antiretroviral therapy is associated with non-AIDS clinical events

BACKGROUND

Even with antiretroviral therapy (ART), persons with HIV (PWH) experience increased morbidity and mortality. Cytomegalovirus (CMV) and Epstein--Barr virus (EBV) co-infections likely exacerbate inflammatory-related diseases.

OBJECTIVE

To determine if presence of detectable CMV or EBV DNA in peripheral blood mononuclear cells (PBMC) is associated with non-AIDS events among PWH receiving modern ART.

DESIGN

We performed a case--control study of PWH starting ART and HIV-suppressed at year 1 and thereafter, 140 cases who experienced non-AIDS events and 305 matched controls. Events included myocardial infarction, stroke, malignancy, serious bacterial infection or death.

METHODS

Blood samples were studied pre-ART, 1-year post-ART and pre-event. Controls had an event-free follow-up equal or greater than cases. CMV and EBV DNA levels were measured in PBMC. Conditional logistic regression analysis assessed associations and adjusted for relevant covariates; Spearman's correlations compared CMV and EBV DNA levels with other biomarkers.

RESULTS

CMV DNA was detected in PBMC of 25% of participants, EBV DNA was detected in more than 90%. Higher EBV DNA levels were associated with increased risk of events at all time points (odds ratio (OR) per one IQR = 1.5-1.7, all P < 0.009). At year 1, detectable CMV DNA was associated with increased risk of events in most adjusted models (OR = 1.4-1.8, P values ranging 0.03-0.17). Higher levels of CMV and EBV DNA correlated with multiple inflammatory markers and lower CD4/CD8 ratio.

CONCLUSION

In PWH starting ART, detection of CMV and EBV DNA in PBMC was associated with development of non-AIDS events. Clinical trials will be needed to understand causal mechanisms and ways to interrupt them.

Quadruple versus triple combination antiretroviral therapies for treatment naive people with HIV: systematic review and meta-analysis of randomised controlled trials

OBJECTIVE

To evaluate the effects of four drug (quadruple) versus three drug (triple) combination antiretroviral therapies in treatment naive people with HIV, and explore the implications of existing trials for clinical practice and research.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

PubMed, EMBASE, CENTRAL, Web of Science, and the Cumulative Index to Nursing and Allied Health Literature from March 2001 to December 2016 (updated search in PubMed and EMBASE up to June 2018); and reference lists of eligible studies and related reviews.

STUDY SELECTION

Randomised controlled trials comparing quadruple with triple combination antiretroviral therapies in treatment naive people with HIV and evaluating at least one effectiveness or safety outcome.

REVIEW METHODS

Outcomes of interest included undetectable HIV-1 RNA, CD4 T cell count, virological failure, new AIDS defining events, death, and severe adverse effects. Random effects meta-analyses were conducted.

RESULTS

Twelve trials (including 4251 people with HIV) were eligible. Quadruple and triple combination antiretroviral therapies had similar effects on all relevant effectiveness and safety outcomes, with no point estimates favouring quadruple therapy. With the triple therapy as the reference group, the risk ratio was 0.99 (95% confidence interval 0.93 to 1.05) for undetectable HIV-1 RNA, 1.00 (0.90 to 1.11) for virological failure, 1.17 (0.84 to 1.63) for new AIDS defining events, 1.23 (0.74 to 2.05) for death, and 1.09 (0.89 to 1.33) for severe adverse effects. The mean difference in CD4 T cell count increase between the two groups was -19.55 cells/μL (-43.02 to 3.92). In general, the results were similar, regardless of the specific regimens of combination antiretroviral therapies, and were robust in all subgroup and sensitivity analyses.

CONCLUSION

In this study, effects of quadruple combination antiretroviral therapy were not better than triple combination antiretroviral therapy in treatment naive people with HIV. This finding lends support to current guidelines recommending the triple regimen as first line treatment. Further trials on this topic should be conducted only when new research is justified by adequate systematic reviews of the existing evidence. However, this study cannot exclude the possibility that quadruple cART would be better than triple cART when new classes of antiretroviral drugs are made available.

Joint model-based clustering of nonlinear longitudinal trajectories and associated time-to-event data analysis, linked by latent class membership: with application to AIDS clinical studies

Longitudinal and time-to-event data are often observed together. Finite mixture models are currently used to analyze nonlinear heterogeneous longitudinal data, which, by releasing the homogeneity restriction of nonlinear mixed-effects (NLME) models, can cluster individuals into one of the pre-specified classes with class membership probabilities. This clustering may have clinical significance, and be associated with clinically important time-to-event data. This article develops a joint modeling approach to a finite mixture of NLME models for longitudinal data and proportional hazard Cox model for time-to-event data, linked by individual latent class indicators, under a Bayesian framework. The proposed joint models and method are applied to a real AIDS clinical trial data set, followed by simulation studies to assess the performance of the proposed joint model and a naive two-step model, in which finite mixture model and Cox model are fitted separately.

Bayesian joint analysis of heterogeneous- and skewed-longitudinal data and a binary outcome, with application to AIDS clinical studies

In medical studies, heterogeneous- and skewed-longitudinal data with mis-measured covariates are often observed together with a clinically important binary outcome. A finite mixture of joint models is currently used to fit heterogeneous-longitudinal data and binary outcome, in which these two parts are connected by the individual latent class membership. The skew distributions, such as skew-normal and skew-t, have shown beneficial in dealing with asymmetric data in various applications in literature. However, there has been relatively few studies concerning joint modeling of heterogeneous- and skewed-longitudinal data and a binary outcome. In this article, we propose a joint model in which a flexible finite mixture of nonlinear mixed-effects models with skew distributions is connected with binary logistic model by a latent class membership indicator. Simulation studies are conducted to assess the performance of the proposed models and method, and a real example from an AIDS clinical trial study illustrates the methodology by modeling the viral dynamics to compare potential models with different distribution specifications; the analysis results are reported.

Hierarchical mixture models for longitudinal immunologic data with heterogeneity, non-normality, and missingness

It is a common practice to analyze longitudinal data frequently arisen in medical studies using various mixed-effects models in the literature. However, the following issues may standout in longitudinal data analysis: (i) In clinical practice, the profile of each subject's response from a longitudinal study may follow a "broken stick" like trajectory, indicating multiple phases of increase, decline and/or stable in response. Such multiple phases (with changepoints) may be an important indicator to help quantify treatment effect and improve management of patient care. To estimate changepoints, the various mixed-effects models become a challenge due to complicated structures of model formulations; (ii) an assumption of homogeneous population for models may be unrealistically obscuring important features of between-subject and within-subject variations; (iii) normality assumption for model errors may not always give robust and reliable results, in particular, if the data exhibit non-normality; and (iv) the response may be missing and the missingness may be non-ignorable. In the literature, there has been considerable interest in accommodating heterogeneity, non-normality or missingness in such models. However, there has been relatively little work concerning all of these features simultaneously. There is a need to fill up this gap as longitudinal data do often have these characteristics. In this article, our objectives are to study simultaneous impact of these data features by developing a Bayesian mixture modeling approach-based Finite Mixture of Changepoint (piecewise) Mixed-Effects (FMCME) models with skew distributions, allowing estimates of both model parameters and class membership probabilities at population and individual levels. Simulation studies are conducted to assess the performance of the proposed method, and an AIDS clinical data example is analyzed to demonstrate the proposed methodologies and to compare modeling results of potential mixture models under different scenarios.

NRTI Sparing Therapy in Virologically Controlled HIV-1 Infected Subjects: Results of a Controlled, Randomized Trial (Probe)

Dual treatments could help clinicians to avoid drawbacks and toxicities due to the nucleosidic backbone, while maintaining the efficacy and convenience of robust combination antiretroviral therapy (cART). We explored the combination of rilpivirine plus boosted darunavir (DRV) as an option when switching from standard cART in patients who are virologically suppressed. In this randomized, open-label, proof-of-concept, noninferiority trial, we recruited patients aged 18 years or older with chronic HIV-1 infection and on a stable, effective (>6 months) protease inhibitor-based cART including a nucleosidic backbone. The primary endpoint was noninferiority of the virological response between treatment groups, according to FDA snapshot approach. Sixty patients were randomly allocated to dual treatment with rilpivirine plus boosted DRV or to continue their ongoing triple treatment. Noninferiority was shown at the prespecified level of -12% both at 24 and 48 weeks. At week 24, 100% of patients in the dual arm presented a blood HIV-RNA level <50 copies per milliliter compared with 90.1% in the triple drug arm (difference 9.9%, 95% CI: -0.7 to 20.7), whereas, at 48 weeks, the same proportions were 96.7% and 93.4%, respectively (difference 3.3%, 95% CI: -7.15 to 13.5). The mean change in CD4 cell count from baseline was 6.0 cells per microliter (SD, 184) for dual treatment and 16.5 cells per microliter (SD, 142) for triple treatment. A relevant decrement in CD838HLADR cells was observed in both arms. The reduction was, however, significantly more pronounced in the dual-therapy arm. At week 48, the CD838HLADR cell count was 3.4% (SD, 2.2) in the dual-therapy arm and 5.2% (SD, 3.1) in the triple arm (P = 0.018). None of the patients developed severe adverse events nor had to stop treatment because of adverse events or presented grade 3-4 laboratory abnormalities. A greater reduction of bone stiffness (-2.25; SD, 7.1) was observed in patients randomized to continue triple therapy compared with patients switched to dual therapy (-0.32; SD, 8.8). Finally, baseline HIV-DNA content directly correlated with pre-cART viral load of patients (P = 0.021), but not with time on cART or time with HIV-RNA below 50 copies per milliliter. Independently of the study arm, patients with a n HIV-RNA level constantly above 3 copies per milliliter or showing viral blips had baseline HIV-DNA levels significantly higher (64,656 copies per 10 cells; SD, 93057) compared with patients who constantly presented a HIV-RNA level below the detection limit of 3 copies per milliliter (14,457 copies per 10 cells; SD, 14098) (P = 0.001). A rilpivirine-boosted plus ritonavir-boosted DRV therapy was not inferior over 48 weeks to a standard boosted protease inhibitor-based triple cART. The dual therapy did not negatively affect lipid profile and renal function and was more friendly on bone metabolism. This approach constitutes an alternative for patients experiencing nucleoside reverse transcriptase inhibitor-related toxicities.

Bayesian quantile regression-based nonlinear mixed-effects joint models for time-to-event and longitudinal data with multiple features

This article explores Bayesian joint models for a quantile of longitudinal response, mismeasured covariate and event time outcome with an attempt to (i) characterize the entire conditional distribution of the response variable based on quantile regression that may be more robust to outliers and misspecification of error distribution; (ii) tailor accuracy from measurement error, evaluate non-ignorable missing observations, and adjust departures from normality in covariate; and (iii) overcome shortages of confidence in specifying a time-to-event model. When statistical inference is carried out for a longitudinal data set with non-central location, non-linearity, non-normality, measurement error, and missing values as well as event time with being interval censored, it is important to account for the simultaneous treatment of these data features in order to obtain more reliable and robust inferential results. Toward this end, we develop Bayesian joint modeling approach to simultaneously estimating all parameters in the three models: quantile regression-based nonlinear mixed-effects model for response using asymmetric Laplace distribution, linear mixed-effects model with skew-t distribution for mismeasured covariate in the presence of informative missingness and accelerated failure time model with unspecified nonparametric distribution for event time. We apply the proposed modeling approach to analyzing an AIDS clinical data set and conduct simulation studies to assess the performance of the proposed joint models and method. Copyright © 2016 John Wiley & Sons, Ltd.

Comparative Safety and Neuropsychiatric Adverse Events Associated With Efavirenz Use in First-Line Antiretroviral Therapy: A Systematic Review and Meta-Analysis of Randomized Trials

INTRODUCTION

Efavirenz (EFV) is widely used for the treatment of antiretroviral-naive HIV-positive individuals, but there are concerns about the risk of adverse neuropsychiatric events. We systematically reviewed the safety of EFV in first-line therapy.

METHODS

Four databases were searched until October 2014 for randomized trials comparing EFV against non-EFV-based regimens for the treatment of antiretroviral-naive HIV-positive adults and children. The primary outcome was drug discontinuation as a result of any adverse event. Relative risks and proportions were pooled using random-effects meta-analysis.

RESULTS

Forty-two trials were included for review. A lower relative and absolute risk of discontinuations due to adverse drug reactions was seen with EFV compared to nevirapine. The relative and absolute risk of discontinuation was greater for EFV compared with low-dose EFV, rilpivirine, tenofovir, atazanavir, and maraviroc. The relative risk of discontinuation was greater for EFV compared with dolutegravir and raltegravir, but absolute risks were not significantly different. There was no difference in the risk of any severe clinical adverse events for any comparison. With the exception of dizziness, fewer than 10% of patients exposed to EFV experienced any other specific type of neuropsychiatric event. No suicides were reported.

CONCLUSIONS

This review found that over 90% of patients remained on an EFV-based first-line regimen after an average follow-up time of 78 weeks. The relative risk of discontinuations due to adverse events was higher for EFV compared with most other first-line options, but absolute differences were less than 5% for all comparisons.

A Bayesian mixture of semiparametric mixed-effects joint models for skewed-longitudinal and time-to-event data

In longitudinal studies, it is of interest to investigate how repeatedly measured markers in time are associated with a time to an event of interest, and in the mean time, the repeated measurements are often observed with the features of a heterogeneous population, non-normality, and covariate measured with error because of longitudinal nature. Statistical analysis may complicate dramatically when one analyzes longitudinal-survival data with these features together. Recently, a mixture of skewed distributions has received increasing attention in the treatment of heterogeneous data involving asymmetric behaviors across subclasses, but there are relatively few studies accommodating heterogeneity, non-normality, and measurement error in covariate simultaneously arose in longitudinal-survival data setting. Under the umbrella of Bayesian inference, this article explores a finite mixture of semiparametric mixed-effects joint models with skewed distributions for longitudinal measures with an attempt to mediate homogeneous characteristics, adjust departures from normality, and tailor accuracy from measurement error in covariate as well as overcome shortages of confidence in specifying a time-to-event model. The Bayesian mixture of joint modeling offers an appropriate avenue to estimate not only all parameters of mixture joint models but also probabilities of class membership. Simulation studies are conducted to assess the performance of the proposed method, and a real example is analyzed to demonstrate the methodology. The results are reported by comparing potential models with various scenarios.

Barriers to antiretroviral therapy adherence and plasma HIV RNA suppression among AIDS clinical trials group study participants

We conducted a secondary data analysis of 11 AIDS Clinical Trials Group (ACTG) studies to examine longitudinal associations between 14 self-reported antiretroviral therapy (ART) adherence barriers (at 12 weeks) and plasma HIV RNA (at 24 weeks) and to discern the relative importance of these barriers in explaining virologic detectability. Studies enrolled from 1997 to 2003 and concluded between 2002 and 2012. We included 1496 (54.2% of the original sample) with complete data. The most commonly selected barriers were "away from home" (21.9%), "simply forgot" (19.6%), "change in daily routine" (19.5%), and "fell asleep/slept through dosing time" (18.9%). In bivariate analyses, "too many pills to take" (OR=0.43, p<0.001), "wanted to avoid side effects" (OR=0.54, p=0.001), "felt drug was toxic/harmful" (OR=0.44, p<0.001), "felt sick or ill" (OR=0.49, p<0.001), "felt depressed/overwhelmed" (OR=0.58, p=0.004), and "problem taking pills at specified time" (OR=0.71, p=0.04) were associated with a lower odds of an undetectable HIV RNA. "Too many pills to take," "wanted to avoid side effects," "felt drug was toxic/harmful," "felt sick/ill,", and "felt depressed/overwhelmed" had the highest relative importance in explaining virologic detectability. "Simply forgot" was not associated with HIV RNA (OR=0.99, p=0.95) and was ninth in its relative importance. Adherence interventions should prioritize barriers with highest importance in explaining virologic outcomes rather than focusing on more commonly reported barriers.

Quadruple-Drug Induction HAART in Advanced HIV Infection

A randomized controlled study exploring an induction-maintenance strategy was performed with a quadruple-drug regimen: zidovudine/lamivudine/abacavir/nevirapine. The study was prematurely interrupted due to the high proportion of adverse events. The median time on protocol-defined therapy was 110 days; 13/28 (46%) patients interrupted therapy and 2/6 tested patients selected praecox viral mutants. Despite this, we observed a significant (p </= .001) increment of CD4. The theoretical advantages of induction-maintenance strategies are tempered by an increased risk of adverse experiences.

Factors associated with CD8+ T-cell activation in HIV-1-infected patients on long-term antiretroviral therapy

BACKGROUND

Abnormal levels of CD8 T-cell activation persist in HIV-1-infected patients on suppressive antiretroviral therapy (ART) and may be deleterious.

METHODS

CD8 T-cell activation (% coexpressing CD38/HLA-DR) was analyzed on blood specimens from 833 HIV-1-infected patients on ART for ≥96 weeks with concurrent plasma HIV RNA (vRNA) ≤200 copies per milliliter. Factors associated with CD8 T-cell activation were assessed using generalized estimating equations to incorporate longitudinal measurements (median 4/participant).

RESULTS

Participants were 84% men, 47% white, 28% black, and 22% Hispanic, with median pre-ART age 38 years and median ART exposure 144 weeks. CD8 T-cell activation was higher at timepoints when vRNA was 51-200 versus ≤50 copies per milliliter [mean CD8 T-cell activation 23.4% vs. 19.7%; adjusted difference: 1.7% (95% confidence interval: 0.1 to 3.4), P = 0.042]. Restricting to vRNA ≤50 copies per milliliter, multivariable models showed the following factors associated with higher CD8 T-cell activation: older age [≥45 vs. ≤30 years: 3.6% (1.4 to 5.7), P = 0.004], hepatitis C virus antibody positivity [3.6% (0.9 to 6.2), P = 0.032], Hispanic vs. white [7.2% (5.3 to 9.0), P < 0.001], lower concurrent CD4 count [≤200 vs. >500 cells/mm: 2.2% (0.7 to 3.7), P < 0.001], lower concurrent CD4/CD8 ratio [-2.6% (-3.7 to -1.5) per 0.5 unit increase, P < 0.001], and higher pre-ART CD8 T-cell activation [2.0% (1.6 to 2.5) per 10% higher, P < 0.001].

CONCLUSIONS

In participants included in our analysis, residual low-level viremia between 51 and 200 copies per milliliter during ART was shown to be associated with greater CD8 T-cell activation than full suppression to <50 copies per milliliter. Older age, hepatitis C virus antibody positivity, race/ethnicity, higher pre-ART CD8 T-cell activation, and lower concurrent CD4/CD8 ratio and CD4 T-cell count also contribute to greater CD8 T-cell activation during suppressive ART.

Regulatory T cells and the risk of CMV end-organ disease in patients with AIDS

OBJECTIVES

Cytomegalovirus (CMV)-specific T-cell effectors (CMV-Teff) protect against CMV end-organ disease (EOD). In HIV-infected individuals, their numbers and function vary with CD4 cell numbers and HIV load. The role of regulatory T cells (Treg) in CMV-EOD has not been extensively studied. We investigated the contribution of Treg and Teff toward CMV-EOD in HIV-infected individuals independently of CD4 cell numbers and HIV load and controlling for CMV reactivations.

DESIGN

We matched 43 CMV-EOD cases to 93 controls without CMV-EOD, but with similar CD4 cell numbers and HIV plasma RNA. CMV reactivation was investigated by blood DNA polymerase chain reaction over 32 weeks preceding the CMV-EOD in cases and preceding the matching point in controls.

METHODS

CMV-Teff and Treg were characterized by the expression of interferon-γ (IFN-γ), interleukin 2, tumor necrosis factor α (TNFα), MIP1β, granzyme B (GrB), CD107a, TNFα, FOXP3, and CD25.

RESULTS

Sixty-five percent cases and 20% controls had CMV reactivations. In multivariate analyses that controlled for CMV reactivations, none of the CMV-Teff subsets correlated with protection, but high CMV-GrB enzyme-linked immunosorbent spot responses and CMV-specific CD4FOXP3+%, CD4TNFα+%, and CD8CD107a% were significant predictors of CMV-EOD.

CONCLUSIONS

Because both FOXP3 and GrB have been previously associated with Treg activity, we conclude that CMV-Treg may play an important role in the development of CMV-EOD in advanced HIV disease. We were not able to identify a CMV-Teff subset that could be used as a surrogate of protection against CMV-EOD in this highly immunocompromised population.

Viral suppression in HIV studies: combining times to suppression and rebound

In HIV-1 clinical trials the interest is often to compare how well treatments suppress the HIV-1 RNA viral load. The current practice in statistical analysis of such trials is to define a single ad hoc composite event which combines information about both the viral load suppression and the subsequent viral rebound, and then analyze the data using standard univariate survival analysis techniques. The main weakness of this approach is that the results of the analysis can be easily influenced by minor details in the definition of the composite event. We propose a straightforward alternative endpoint based on the probability of being suppressed over time, and suggest that treatment differences be summarized using the restricted mean time a patient spends in the state of viral suppression. A nonparametric analysis is based on methods for multiple endpoint studies. We demonstrate the utility of our analytic strategy using a recent therapeutic trial, in which the protocol specified a primary analysis using a composite endpoint approach.

Peripheral neuropathy in ART-experienced patients: prevalence and risk factors

Peripheral neuropathy (PN) is a common neurological complication of HIV infection that has debilitating effects on quality of life. While there has been a comprehensive evaluation of the prevalence of neuropathic signs/symptoms and risk factors (RFs) for PN or symptomatic PN (SPN) with initiation of combination antiretroviral therapy (cART) in ART-naïve patients, similar evaluation in ART-experienced patients is limited. This study investigated the prevalence and RFs for PN/SPN in ART-experienced patients enrolled in clinical salvage therapy studies. Between February 2000 and June 2007, 522 ART-experienced participants who experienced virologic failure with a prior regimen and started new regimens were followed longitudinally and annually screened for signs and symptoms of PN. Rates of PN/SPN at 3 years since parent study entry were 52.8 and 24.0 %, respectively. Aging, taller height, protease inhibitor use, and female sex were significant RFs for PN/SPN. The use of statin drugs was significantly associated with lower odds of SPN, and it may prevent progression from no SPN to SPN.

Racial differences in response to antiretroviral therapy for HIV infection: an AIDS clinical trials group (ACTG) study analysis

BACKGROUND

In the United States, black individuals infected with human immunodeficiency virus (HIV) have higher rates of virologic failure on antiretroviral therapy (ART) and of death compared to white individuals. The cause for these disparities is uncertain. We sought to examine differences in virologic outcomes among antiretroviral-naive clinical trial participants starting randomized ART and to investigate factors to explain the differences.

METHODS

Individual-level data from participants initiating ART in 5 AIDS Clinical Trials Group studies were analyzed. Included studies were those conducted during 1998-2006 with a primary outcome of virologic failure. The primary outcome measure was time to virologic failure, regardless of ART changes.

RESULTS

A total of 2495 individuals (1151 black; 1344 white) were included with a median follow-up of 129 weeks. Compared to whites, blacks had an increased hazard of virologic failure (hazard ratio [HR]; 1.7; 95% confidence interval [CI], 1.4-1.9; P < .001), with no evidence of heterogeneity across regimens (P = .97); the association remained after adjustment for measured confounders (HR, 1.4; 95% CI, 1.2-1.6; P < .001). Increased hazard of virologic failure was associated with younger age, higher pretreatment HIV type 1 RNA level, lower pretreatment CD4 cell count, hepatitis C antibody, less education, and recent nonadherence to treatment. Sensitivity analyses with different endpoint definitions demonstrated similar results.

CONCLUSIONS

In this analysis, blacks had a 40% higher virologic failure risk than whites that was not explained by measured confounders. The observation was consistent over a range of regimens, suggesting that the difference may be driven by social factors; however, biological factors cannot be ruled out. Further research should identify the sources of racial disparities and develop strategies to reduce them.

The impact of age on the prognostic capacity of CD8+ T-cell activation during suppressive antiretroviral therapy

OBJECTIVE

To assess whether CD8 T-cell activation predicts risk of AIDS and non-AIDS morbidity during suppressive antiretroviral treatment (ART).

DESIGN

Post-hoc analyses of ART-naive participants in prospective ART studies. Participants with HIV-RNA levels 200 copies/ml or less and CD8 T-cell activation data (%CD38HLA-DR) at year-1 of ART were selected to determine years 2-5 incidence of AIDS and non-AIDS events.

METHODS

We censored data at time of ART interruption or virologic failure. Inverse probability of censoring-weighted logistic regression was used to correct for informative censoring.

RESULTS

We included 1025 participants; 82% were men, median age 38 years, pre-ART CD4 cell count 255 cells/μl, and year-1-activated CD8 T cells 24%. Of these, 752 had 5 years of follow-up; 379 remained on ART and had no confirmed plasma HIV-RNA more than 200 copies/ml. The overall probability of an AIDS or non-AIDS event in years 2-5 was estimated at 13% [95% confidence interval (CI) 10-15%] had everyone remained on suppressive ART. Higher year-1-activated CD8 T-cell percentage increased the probability of subsequent events [odds ratio 1.22 per 10% higher (95% CI 1.04-1.44)]; this effect was not significant after adjusting for age. Among those age 50 years at least (n=108 at year 1), the probability of an event in years 2-5 was 37% and the effect of CD8 T-cell activation was more apparent (odds ratio=1.42, P=0.02 unadjusted and adjusted for age).

CONCLUSION

CD8 T-cell activation is prognostic of clinical events during suppressive ART, although this association is confounded by age. The consequences of HIV-associated immune activation may be more important in patients 50 years and older.

Sleep quality in efavirenz-treated Chinese HIV patients – comparing between GT and GG genotype of CYP2B6-516 G/T polymorphisms

Seventy-two adult Chinese HIV-positive treatment-naïve patients were recruited in a study to evaluate prospectively the associations between CYP2B6 516 G/T polymorphisms and sleep quality following treatment with an efavirenz-based regimen. Overall, the patients gave an allelic frequency of 0.3 for CYP2B6 516 T, and a genotype frequency of 9.4% for TT. Compared to GG, GT gave a higher median value of plasma efavirenz level at four weeks (3.77 mg/L vs 2.59 mg/L, p < 0.001) and 12 months (3.57 mg/L vs 2.97 mg/L, p = 0.026). Using generalised estimating equations analysis to track the variance over time, there was poorer Pittsburgh Sleep Quality Index in GT compared to GG, while GT was associated with a higher efavirenz level of >4 mg/L. There was however no difference in the component sleep scores nor was there direct association between sleep quality and plasma efavirenz levels. The results suggested that CYP2B6 genotype was associated with different patterns of sleep problems, further investigation of which is warranted with the objective of optimizing therapy with efavirenz-based regimens.

Anthropometric differences between HIV-infected individuals prior to antiretroviral treatment and the general population from 1998-2007: the AIDS Clinical Trials Group Longitudinal Linked Randomized Trials (ALLRT) cohort and NHANES

OBJECTIVE

To assess differences in body circumferences and body mass index (BMI, kg/m(2)) between antiretroviral treatment (ART) naïve HIV-infected and HIV-uninfected persons.

METHODS

Waist, arm, and thigh circumferences and BMI were measured within the ALLRT and NHANES cohorts between 1998 and 2007. ALLRT is a prospective, longitudinal study of U.S. participants enrolled in randomized HIV treatment studies conducted by the AIDS Clinical Trials Group (ACTG). NHANES is a representative group of the US population. The cohorts were analyzed in two time periods, to account for trends towards increased adiposity. Anthropometrics were displayed in percentiles by age and sex. Multiple linear regression models examined differences between cohorts.

RESULTS

ALLRT had more males (82% versus 48%, p<0.0001), more black participants (32% versus 23%, p<0.0001), and less Hispanics (21% versus 30%, p<0.0001) than NHANES. Mean BMI was smaller in ALLRT males and females compared to NHANES by 1.6-2.4 kg/m(2) (p<0.0001). Mean waist and arm circumferences in both sexes and time periods were significantly smaller in ALLRT than in NHANES (p<0.0001). Mean thigh circumference in ALLRT was also smaller than NHANES among males (p<0.0001 in both time periods) and females (p = 0.01 in the early time period).

CONCLUSIONS

Differences in anthropometrics existed prior to ART initiation, in this large national cohort of HIV-infected individuals, compared to a representative HIV-uninfected cohort, indicating that HIV and its complications have important effects on body shape. Further longitudinal examination of anthropometrics in this HIV-infected cohort may provide additional insight into disease risk.

TRIAL REGISTRATION

NCT00001137 at www.clinicaltrials.gov.

Intensification of antiretroviral therapy through addition of enfuvirtide in naive HIV-1-infected patients with severe immunosuppression does not improve immunological response: results of a randomized multicenter trial (ANRS 130 Apollo)

We studied whether addition of enfuvirtide (ENF) to a background combination antiretroviral therapy (cART) would improve the CD4 cell count response at week 24 in naive patients with advanced HIV disease. ANRS 130 Apollo is a randomized study, conducted in naive HIV-1-infected patients, either asymptomatic with CD4 counts of <100/mm(3) or stage B/C disease with CD4 counts of <200/mm(3). Patients received tenofovir-emtricitabine with lopinavir-ritonavir (LPV/r) or efavirenz and were randomized to receive ENF for 24 weeks (ENF arm) or not (control arm). The primary endpoint was the proportion of patients with CD4 counts of ≥ 200/mm(3) at week 24. A total of 195 patients were randomized: 73% had stage C disease, 78% were male, the mean age was 44 years, the median CD4 count was 30/mm(3), and the median HIV-1 RNA load was 5.4 log(10) copies/ml. Eighty-one percent of patients received LPV/r. One patient was lost to follow-up, and eight discontinued the study (four in each arm). The proportions of patients with CD4 counts of ≥ 200/mm(3) at week 24 were 34% and 38% in the ENF and control arms, respectively (P = 0.53). The proportions of patients with HIV-1 RNA loads of <50 copies/ml were 74% and 58% at week 24 in the ENF and control arms, respectively (P < 0.02), and the proportion reached 79% in both arms at week 48. Twenty (20%) and 12 patients (13%) in the ENF and control arms, respectively, experienced at least one AIDS event during follow-up (P = 0.17). Although inducing a more rapid virological response, addition of ENF to a standard cART does not improve the immunological outcome in naive HIV-infected patients with severe immunosuppression.

No advantage of quadruple- or triple-class antiretroviral therapy as initial treatment in patients with very high viraemia

BACKGROUND

We assessed whether quadruple or triple-class therapy for the initial treatment of HIV-1 infection provides a virological benefit over standard triple therapy in patients with very high plasma viraemia. The assessment was made based on a national observational HIV cohort in the Netherlands.

METHODS

Inclusion criteria were age ≥18 years, treatment-naive, plasma viral load (pVL) ≥500,000 copies/ml and initiation of quadruple or triple therapy between 2001 and 2011. Time to viral suppression, defined as pVL<50 copies/ml, was compared between the two groups using Kaplan-Meier plots and multivariate Cox regression analysis.

RESULTS

A total of 675 patients were included: 125 (19%) initiated quadruple and 550 (81%) triple therapy. Median pVL was 5.9 (IQR 5.8-6.1) log(10) copies/ml in both groups (P=0.49). 22 (18%) patients on quadruple and 63 (12%) on triple therapy interrupted the treatment regimen because of drug-related toxicity (P=0.06). Median time to viral suppression was 5.8 (IQR 4.6-7.9) and 6.0 (4.0-9.4) months in the patients on quadruple and triple therapy, respectively (log-rank, P=0.42). In the adjusted Cox analysis, quadruple therapy was not associated with time to viral suppression (HR 1.07 [95% CI 0.86, 1.33], P=0.53). Similar results were seen when comparing triple- versus dual-class therapy (n=72 versus n=601, respectively).

CONCLUSIONS

Initial quadruple- or triple-class therapy was equally effective as standard triple therapy in the suppression of HIV-1 in treatment-naive patients with very high viraemia and did not result in faster pVL decreases, but did expose patients to additional toxicity.

HIV peripheral neuropathy progression: protection with glucose-lowering drugs?

The purpose of this study is to evaluate risk factors for progression from asymptomatic peripheral neuropathy (APN) to symptomatic peripheral neuropathy (SPN). Antiretroviral therapy (ART)-naïve patients initiating combination ART were followed longitudinally and screened for signs/symptoms of PN. Having APN was associated with higher odds of future SPN (odds ratio (OR) = 1.58, 95 % confidence interval (CI) = (1.08, 2.29), p = 0.027). Neurotoxic ART use was associated with increased odds of progression to SPN (OR = 2.16, 95 % CI = (1.21, 3.85), p = 0.009) while use of glucose-lowering drugs (non-insulin) was protective (OR = 0.12, 95 % CI = (0.02, 0.83), p = 0.031). Use of glucose-lowering drugs (non-insulin) may prevent progression from APN to SPN.

Telephone consultation for improving health of people living with or at risk of HIV: a systematic review

BACKGROUND

Low cost, effective interventions are needed to deal with the major global burden of HIV/AIDS. Telephone consultation offers the potential to improve health of people living with HIV/AIDS cost-effectively and to reduce the burden on affected people and health systems. The aim of this systematic review was to assess the effectiveness of telephone consultation for HIV/AIDS care.

METHODS

We undertook a comprehensive search of peer-reviewed and grey literature. Two authors independently screened citations, extracted data and assessed the quality of randomized controlled trials which compared telephone interventions with control groups for HIV/AIDS care. Telephone interventions were voice calls with landlines or mobile phones. We present a narrative overview of the results as the obtained trials were highly heterogeneous in design and therefore the data could not be pooled for statistical analysis.

RESULTS

The search yielded 3321 citations. Of these, nine studies involving 1162 participants met the inclusion criteria. The telephone was used for giving HIV test results (one trial) and for delivering behavioural interventions aimed at improving mental health (four trials), reducing sexual transmission risk (one trial), improving medication adherence (two trials) and smoking cessation (one trial). Limited effectiveness of the intervention was found in the trial giving HIV test results, in one trial supporting medication adherence and in one trial for smoking cessation by telephone.

CONCLUSIONS

We found some evidence of the benefits of interventions delivered by telephone for the health of people living with HIV or at risk of HIV. However, only limited conclusions can be drawn as we only found nine studies for five different interventions and they mainly took place in the United States. Nevertheless, given the high penetration of low-cost mobile phones in countries with high HIV endemicity, more evidence is needed on how telephone consultation can aid in the delivery of HIV prevention, treatment and care.

A systematic review of the psychiatric side-effects of efavirenz

Concerns regarding the use of efavirenz in patients with a history of mental illness may predispose clinicians to not offer this agent to psychiatrically ill populations in spite of the convenience of once daily dosing, which can result in improved adherence in these at-risk populations. This systematic review examines the current data regarding the neuropsychiatric effects of efavirenz, and also attempts to provide guidance to clinicians using efavirenz to treat patients with mental illness. The review identified high rates of neuropsychiatric side effects including vivid dreams, insomnia and mood changes in approximately 50% of patients who initiate efavirenz. The effects begin quickly, commonly peak in the first 2 weeks, and are generally mild and transient in nature. Isolated case reports and uncontrolled data suggest higher rates of severe side effects; however, there is no clear evidence of a broadly increased risk of suicide or dangerous behavior for patients taking efavirenz as part of their antiretroviral regimen.

Does HAART efficacy translate to effectiveness? Evidence for a trial effect

BACKGROUND

Patients who participate in clinical trials may experience better clinical outcomes than patients who initiate similar therapy within clinical care (trial effect), but no published studies have evaluated a trial effect in HIV clinical trials.

METHODS

To examine a trial effect we compared virologic suppression (VS) among patients who initiated HAART in a clinical trial versus in routine clinical care. VS was defined as a plasma HIV RNA ≤ 400 copies/ml at six months after HAART initiation and was assessed within strata of early (1996-99) or current (2000-06) HAART periods. Risk ratios (RR) were estimated using binomial models.

RESULTS

Of 738 persons initiating HAART, 30.6% were women, 61.7% were black, 30% initiated therapy in a clinical trial and 67% (n =  496) had an evaluable six month HIV RNA result. HAART regimens differed between the early and current periods (p < 0.001); unboosted PI regimens (55.6%) were more common in the early and NNRTI regimens (46.4%) were more common in the current period. Overall, 78% (95%CI 74, 82%) of patients achieved VS and trial participants were 16% more likely to achieve VS (unadjusted RR 1.16, 95%CI 1.06, 1.27). Comparing trial to non-trial participants, VS differed by study period. In the early period, trial participants initiating HAART were significantly more likely to achieve VS than non-trial participants (adjusted RR 1.33; 95%CI 1.15, 1.54), but not in the current period (adjusted RR 0.98; 95%CI 0.87, 1.11).

CONCLUSIONS

A clear clinical trial effect on suppression of HIV replication was observed in the early HAART period but not in the current period.

Lower CD4 cell count and higher virus load, but not antiretroviral drug resistance, are associated with AIDS-defining events and mortality: an ACTG Longitudinal Linked Randomized Trials (ALLRT) analysis

BACKGROUND

We hypothesized that drug resistance mutations would impact clinical outcomes associated with HIV-1 infection.

METHODS

A matched case-control study of participants in AIDS Clinical Trials Group Longitudinal Linked Randomized Trials (ALLRT). Cases experienced an AIDS-defining event (ADE) or mortality, and controls did not. One hundred thirty-four cases were identified and matched to a total of 266 controls by age, sex, treatment regimen, and length of follow-up. Both cases and controls had HIV RNA levels of ≥ 500 copies/mL within 24 weeks of an event. Population-based genotyping at or near the time of the event was used to evaluate the impact of resistance mutations on incidence of ADE and/or death using conditional logistic regression models.

RESULTS

One hundred four cases and 183 controls were analyzed. Median time to event was 99 weeks; 6 cases were deaths. At baseline, cases had lower CD4 (median 117 vs 235 cells/mm3; P < .0001) and higher HIV RNA levels (median 205,000 vs 57,000 copies/mL; P = .003). No significant differences in resistance were seen between cases and controls.

CONCLUSIONS

In this rigorously designed case-control study, lower CD4 cell counts and higher virus loads, not antiretroviral drug resistance, were strongly associated with ADE and mortality.

Incidence of non-AIDS-defining cancer in antiretroviral treatment-naïve subjects after antiretroviral treatment initiation: an ACTG longitudinal linked randomized trials analysis

BACKGROUND

Prospective data on factors associated with the non-AIDS-defining cancer (NADC) incidence in HIV-infected individuals are limited.

METHODS

We examined the NADC incidence in 3,158 antiretroviral treatment (ART)-naïve subjects after ART initiation in AIDS Clinical Trials Group trials; extended follow-up was available for 2,122 subjects. Poisson regression was used to examine the associations between covariates and incident NADC.

RESULTS

At ART initiation, subjects (median age 37 years) were 40% non-Hispanic whites, and 82% were male; 23% had CD4+ T cell count ≤ 50 cells/mm³ and 25% had CD4 >350 cells/mm³. Median follow-up was 3.8 years. Among 64 incident NADCs, the most common were 8 anal cancers, 8 basal cell carcinomas, 8 Hodgkin's disease, and 6 lung cancers. In univariate models, age, smoking and recent (time-updated) CD4 were associated with incident NADC. There was no association between initial ART drug class (protease inhibitor, nucleoside reverse transcriptase inhibitor and nonnucleoside reverse transcriptase inhibitor) and NADC. After adjusting for age, race and sex: smoking [relative risk = 2.12 (95% CI = 1.1-4.08)] and recent CD4 (≤ 50 cells/mm³: 3.58, 1.22-10.45; 51-200 cells/mm³: 2.54, 1.30-5.0; 201-350 cells/mm³: 2.37, 1.32-4.26 vs. >350 cells/mm³) were associated with NADC.

CONCLUSION

Smoking and lower recent CD4 levels, but not initial ART drug class, were associated with NADC. Strategies for maintaining higher CD4 cell counts and successful smoking cessation may reduce the NADC incidence in the HIV-infected population.

Peripheral neuropathy in HIV: prevalence and risk factors

OBJECTIVES

To estimate neuropathic sign/symptom rates with initiation of combination antiretroviral therapy (cART) in HIV-infected ART-naive patients, and to investigate risk factors for: peripheral neuropathy and symptomatic peripheral neuropathy (SPN), recovery from peripheral neuropathy/SPN after neurotoxic ART (nART) discontinuation, and the absence of peripheral neuropathy/SPN while on nART.

DESIGN

AIDS Clinical Trials Group (ACTG) Longitudinal Linked Randomized Trial participants who initiated cART in randomized trials for ART-naive patients were annually screened for symptoms/signs of peripheral neuropathy. ART use and disease characteristics were collected longitudinally.

METHODS

Peripheral neuropathy was defined as at least mild loss of vibration sensation in both great toes or absent/hypoactive ankle reflexes bilaterally. SPN was defined as peripheral neuropathy and bilateral symptoms. Generalized estimating equation logistic regression was used to estimate associations.

RESULTS

Two thousand, one hundred and forty-one participants were followed from January 2000 to June 2007. Rates of peripheral neuropathy/SPN at 3 years were 32.1/8.6% despite 87.1% with HIV-1RNA 400 copies/ml or less and 70.3% with CD4 greater than 350 cells/μl. Associations with higher odds of peripheral neuropathy included older patient age and current nART use. Associations with higher odds of SPN included older patient age, nART use, and history of diabetes mellitus. Associations with lower odds of recovery after nART discontinuation included older patient age. Associations with higher odds of peripheral neuropathy while on nART included older patient age and current protease inhibitor use. Associations with higher odds of SPN while on nART included older patient age, history of diabetes, taller height, and protease inhibitor use.

CONCLUSION

Signs of peripheral neuropathy remain despite virologic/immunologic control but frequently occurs without symptoms. Aging is a risk factor for peripheral neuropathy/SPN.

No risk of myocardial infarction associated with initial antiretroviral treatment containing abacavir: short and long-term results from ACTG A5001/ALLRT

BACKGROUND

Observational and retrospective clinical trial cohorts have reported conflicting results for the association of abacavir use with risk of myocardial infarction (MI), possibly related to issues that may bias estimation of treatment effects, such as time-varying confounders, informative dropout, and cohort loss due to competing events.

METHODS

We analyzed data from 5056 individuals initiating randomized antiretroviral treatment (ART) in AIDS Clinical Trials Group studies; 1704 started abacavir therapy. An intent-to-treat analysis adjusted for pretreatment covariates and weighting for informative censoring was used to estimate the hazard ratio (HR) of MIs after initiation of a regimen with or without abacavir.

RESULTS

Through 6 years after ART initiation, 36 MI events were observed in 17,404 person-years of follow-up. No evidence of an increased hazard of MI in subjects using abacavir versus no abacavir was seen (over a 1-year period: P=.50; HR, 0.7 [95% confidence interval {CI}, 0.2-2.4]); over a 6-year period: P=.24; HR, 0.6 [95% CI, 0.3-1.4]); these results were robust over as-treated and sensitivity analyses. Although the risk of MI decreased over time, there was no evidence to suggest a time-dependent abacavir effect. Classic cardiovascular disease (CVD) risk factors were the strongest predictors of MI.

CONCLUSION

We find no evidence to suggest that initial ART containing abacavir increases MI risk over short-term and long-term periods in this population with relatively low MI risk. Traditional CVD risk factors should be the main focus in assessing CVD risk in individuals with human immunodeficiency virus infection.

A randomized, placebo-controlled trial of abacavir intensification in HIV-1-infected adults with virologic suppression on a protease inhibitor-containing regimen

BACKGROUND AND OBJECTIVE

Maximizing the durability of viral suppression is a key goal of antiretroviral therapy. The objective of AIDS Clinical Trials Group Study 372A was to determine whether the intensification strategy of adding abacavir to an effective indinavir-dual nucleoside regimen would delay the time to virologic failure.

METHODS

Zidovudine-experienced subjects (n=229) on therapy with indinavir + zidovudine + lamivudine with plasma HIV-1 RNA levels<500 copies/mL were randomized to abacavir 300 mg twice daily or placebo. The primary endpoint was the time to treatment failure, defined as a composite of confirmed virologic failure (2 consecutive HIV-1 RNAs>200 copies/mL) and treatment discontinuation.

RESULTS

At baseline, the study population was 88% male with a median age of 41 years and median CD4 cell count of 250/mm3. Median follow-up was 4.4 years. The primary endpoint was reached in 61/116 of abacavir versus 62/113 of placebo recipients (P=.77); virologic failure occurred in 34/116 and 42/113 patients, respectively (P=.22). There were no differences in the proportions of subjects with plasma HIV-1 RNA levels below 50 copies/mL, in CD4 cell count increases, nor adverse events between the arms. In the study, 17% of subjects developed nephrolithiasis, 2% experienced abacavir hypersensitivity, and 4.8% experienced at least 1 serious cardiovascular event (7 [6%] in the abacavir arm, 4 [3.5%] in the placebo arm). In additional secondary and post hoc analyses, rates of intermittent viremia, suppression below a plasma HIV-1 RNA level of 6 copies/mL, and HIV-1 proviral DNA levels in peripheral blood mononuclear cells were not significantly different in the 2 arms.

CONCLUSIONS

The strategy of intensification with abacavir in patients who are virologically suppressed on a stable antiretroviral regimen does not confer a clinical or virologic benefit. As antiretroviral regimens have become more potent since this trial was completed, it will be even more difficult to prove that late intensification of already virologically suppressed patients will add benefit. However, studies are warranted with drugs with new mechanisms of action to determine whether the level of persistent viremia below 50 copies/ mL can be further reduced and what influence this may have on latent HIV reservoirs.

Quality of life in HIV-infected individuals receiving antiretroviral therapy is related to adherence

This study assesses changes in quality of life (QoL) over time among HIV-infected individuals receiving antiretroviral therapy (ART) and evaluates how this relates to ARTadherence. Prospective, longitudinal data were examined from 1050 participants in two large, randomized, multi-centre antiretroviral clinical trials. QoL was assessed by the SF-12; adherence by the Terry Beirn Community Programs for Clinical Research on AIDS Antiretroviral Medication Self-report. Participants included 20% women, 53% African Americans, 16% Latinos; mean age was 39 years; mean baseline CD4+ cell count 230 cells/mm3; 89% were ART-naïve at entry. Baseline physical and mental health summary QoL scores were 45.4 and 42.9, comparable to scores reported in other advanced HIV populations. Significant improvements in mean QoL scores were seen for the group as a whole after 1 to 4 months on new ART regimens, and persisted for 12 months. Participants reporting 100% ART adherence achieved significantly higher QoL scores at 12 months compared to those with poorer adherence, particularly if 100% adherence was consistent (p < 0.001). Those with at least 80% ART adherence had smaller gains in QoL at 12 months when compared to baseline, while those with < 80% adherence had worsening of QoL. In this analysis, ART adherence was associated with improved QoL, particularly if adherence was sustained.

Measurement of naive CD4 cells reliably predicts potential for immune reconstitution in HIV

BACKGROUND

Pathogenesis studies show that naive CD4 cells are preferentially depleted in lymphoid tissues during HIV infection, and studies of advanced patients suggest levels of naive CD4 cells in blood correlate to total CD4 cells after starting antiretroviral therapy (ARV). We hypothesized that measuring naive CD4 cells in blood in people at earlier stages of disease would identify those at highest risk for poor CD4 reconstitution who may benefit from earlier initiation of ARV.

METHODS AND FINDINGS

We identified 348 patients from multiple AIDS Clinical Trials Group studies who were ARV naive, had a CD4 count between 200 and 500 cells per microliter, a measure of pretreatment-naive CD4 percent, and serial follow-up measures of CD4 count and plasma HIV RNA after starting ARV. We used logistic regression to model the ability of naive CD4 percent to predict 100 and 200 CD4 cell increases after 24 months of therapy. After controlling for baseline viral load and demographic variables, baseline naive but not total CD4 cell count strongly predicted CD4 cell increases. Lower baseline naive CD4 percent was associated with greater time spent at lower CD4 T-cell counts after initiating ARV.

CONCLUSIONS

Measurement of naive CD4 percent in patients can identify those least likely to reconstitute immunity, who may benefit from earlier ARV treatment.

AIDS clinical trials group longitudinal linked randomized trials (ALLRT): rationale, design, and baseline characteristics

PURPOSE

ALLRT is a longitudinal cohort study of HIV-infected subjects prospectively randomized into selected clinical trials for antiretroviral (ARV) treatment-naïve and ARV treatment-experienced individuals conducted by the AIDS Clinical Trials Group (ACTG). We describe the rationale, design, and baseline characteristics of the ALLRT cohort and its potential to address important research questions related to ARV therapy.

METHOD

Standardized visits occur every 16 weeks to evaluate long-term clinical, virologic, and immunologic outcomes associated with ARV treatment.

RESULTS

A total of 4,371 subjects enrolled in ALLRT from January 2000 through June 2007. Of these, 3,146 (72%) were ARV naïve at parent study entry (18% female, 44% white, 32% black, 21% Hispanic; median age 37 years, CD4 count 218 cells/microL, follow-up 3.6 years; 343 [11%] followed > or = 8 years) and 1,225 (28%) were treatment experienced (13% female, 59% white, 20% black, 17% Hispanic; median age 42 years, CD4 count 325 cells/microL, follow-up 5.7 years).

CONCLUSIONS

ALLRT provides the opportunity to understand long-term ramifications of therapeutic ARV choices and determine whether these vary by treatment regimen, timing of treatment initiation, or treatment changes over long-term follow-up. Investigations based on uniform data and specimen collection in the context of randomized ARV treatments will be critical to developing more successful long-term therapeutic strategies for HIV treatment.

Design of long-term HIV dynamic studies using semiparametric mixed-effects models

Studies of HIV dynamics in AIDS research are very important in understanding the pathogenesis of HIV-1 infection and also in assessing the effectiveness of antiviral therapies. There are many AIDS clinical trials on HIV dynamics currently in development worldwide, giving rise to many design issues yet to be addressed. For example, most studies are focused on short-term viral dynamics and the existing models may not be applicable to describe long-term virologic response. In this paper, we use a simulation-based approach to study the designs of long-term viral dynamics under semiparametric nonlinear mixed-effects models. These models not only can preserve the meaningful interpretation of the short-term HIV dynamics, but also characterize the long-term virologic responses to antiretroviral (ARV) treatment. We investigate a number of feasible clinical protocol designs similar to those currently used in AIDS clinical trials. In particular, we evaluate whether earlier samplings can result in more useful information about the viral response trajectory; we also evaluate the effectiveness of two strategies: more frequent samplings per subject with fewer subjects versus fewer samplings per subject with more subjects while keeping the total number of samplings constant. The results of our investigation provide quantitative guidance for designing and selecting ARV therapy.

Association of efavirenz hypersusceptibility with virologic response in ACTG 368, a randomized trial of abacavir (ABC) in combination with efavirenz (EFV) and indinavir (IDV) in HIV-infected subjects with prior nucleoside analog experience

PURPOSE

To evaluate the association of efavirenz hypersusceptibility (EFV-HS) with clinical outcome in a double-blind, placebo-controlled, randomized trial of EFV plus indinavir (EFV+IDV) vs. EFV+IDV plus abacavir (ABC) in 283 nucleoside-experienced HIV-infected patients.

METHOD AND RESULTS

Rates of virologic failure were similar in the 2 arms at week 16 (p = .509). Treatment discontinuations were more common in the ABC arm (p = .001). Using logistic regression, there was no association between virologic failure and either baseline ABC resistance or regimen sensitivity score. Using 3 different genotypic scoring systems, EFV-HS was significantly associated with reduced virologic failure at week 16, independent of treatment assignment. In some patients on the nucleoside-sparing arm, the nucleoside-resistance mutation L74V was selected for in combination with the uncommonly occurring EFV-resistance mutations K103N+L100I; L74V was not detected as a minority variant, using clonal sequence analysis, when the nucleoside-sparing regimen was initiated.

CONCLUSION

Premature treatment discontinuations in the ABC arm and the presence of EFV-HS HIV variants in this patient population likely made it difficult to detect a benefit of adding ABC to EFV+IDV. In addition, L74V, when combined with K103N+L100I, may confer a selective advantage to the virus that is independent of its effects on nucleoside resistance.

Bayesian Experimental Design for Long-Term Longitudinal HIV Dynamic Studies

The study of HIV dynamics is one of the most important developments in recent AIDS research for understanding the pathogenesis of HIV-1 infection and antiviral treatment strategies. Currently a large number of AIDS clinical trials on HIV dynamics are in development worldwide. However, many design issues that arise from AIDS clinical trials have not been addressed. In this paper, we use a simulation-based approach to deal with design problems in Bayesian hierarchical nonlinear (mixed-effects) models. The underlying model characterizes the long-term viral dynamics with antiretroviral treatment where we directly incorporate drug susceptibility and exposure into a function of treatment efficacy. The Bayesian design method is investigated under the framework of hierarchical Bayesian (mixed-effects) models. We compare a finite number of feasible candidate designs numerically, which are currently used in AIDS clinical trials from different perspectives, and provide guidance on how a design might be chosen in practice.

Antiretroviral Treatment Strategies and Immune Reconstitution in Treatment-naive HIV-Infected Patients with Advanced Disease

Treatment-naïve advanced HIV-infected patients have a lower life expectancy than those treated early with highly active antiretroviral therapy (HAART). Early treatment allows greater immunological recovery, a reduction of AIDS progression, a reduced risk of related illnesses, and lower mortality compared with HAART initiation in advanced disease. Given the numbers with advanced disease worldwide and the high cost of care, strategies encouraging early detection may be life saving and cost effective. Factors associated with increased clinical progression include higher baseline HIV viral load and older age, emphasizing the need for early viral load suppression. HAART initiation faces many challenges; interactions between antiretroviral agents and drugs used to treat life-threatening opportunistic infections may cause subtherapeutic antiretroviral exposure and the development of resistance or supratherapeutic levels resulting in adverse effects. Immune reconstitution inflammatory syndrome can be another cause of suboptimal outcomes. The management of patients with advanced HIV infection should include rapid short-term immune reconstitution to limit the risk of disease progression plus aggressive antiviral treatment to achieve rapid virological suppression. Clear evidence on the optimal regimen and agents to use to target advanced HIV disease is lacking. Therefore, antiretroviral treatment for these patients has to be carefully tailored to the individual according to many variables.

Switching to a protease inhibitor-containing, nucleoside-sparing regimen (lopinavir/ritonavir plus efavirenz) increases limb fat but raises serum lipid levels: results of a prospective randomized trial (AIDS clinical trial group 5125s)

BACKGROUND

Subcutaneous limb fat loss continues to be one the most troubling side effects of long-term antiretroviral regimens. Nucleoside analogues and protease inhibitors (PIs) have been linked to the development of this complication.

METHODS

We evaluated the effects of nucleoside-sparing and PI-sparing regimens on fat distribution, bone mineral density, and metabolic parameters in 62 subjects, who were not selected for lipoatrophy, with advanced HIV (nadir CD4 count <or=200 cells/mm or HIV RNA level >or=80,000 copies/mL) and an undetectable HIV viral load. Participants were randomized to switch their initial successful antiretroviral regimen to open-label lopinavir/ritonavir (LPV/r) at a dose of 533/133 mg twice a day and efavirenz (EFV) at a dose of 600 mg/d (the nucleoside-sparing arm) versus EFV and 2 nucleoside analogues (the PI-sparing arm).

FINDINGS

At week 48, the median change in limb fat in the nucleoside-sparing arm was 562 g (6%, interquartile range [IQR]: -218-1186 g) versus a loss of -242 g (-4%, IQR: -539-452 g) in the nucleoside-containing PI-sparing arm (P = 0.086). At the time of last observation (median = 102 weeks, IQR: 73-152 weeks), a median gain of 782 g (10%, IQR: -380-1168 g) of limb fat was noted in the nonnucleoside arm (n = 22) versus a loss of 850 g (-15%, IQR: -1270 to -526 g) in the nucleoside-containing arm (n = 25; P = 0.002).

INTERPRETATION

The switch to a nucleoside-sparing combination antiretroviral regimen (LPV/r + EFV) was associated with significant improvement in limb fat. These results provide additional evidence that nucleoside analogues are important in the progressive limb fat loss that characterizes antiretroviral treatment and that switching medications can significantly improve this complication. This option has to be carefully balanced with the potential to increase serum lipid levels and the trend to increase virologic failure.

Efficacy and safety of TMC125 (etravirine) in treatment-experienced HIV-1-infected patients in DUET-2: 24-week results from a randomised, double-blind, placebo-controlled trial

BACKGROUND

TMC125 (etravirine) is a non-nucleoside reverse-transcriptase inhibitor (NNRTI) with activity against NNRTI-resistant HIV-1 in phase IIb trials. The aim of DUET-2 is to examine the efficacy, tolerability, and safety of TMC125 in treatment-experienced patients.

METHODS

In this continuing randomised, double-blind, placebo-controlled, phase III trial, HIV-1-infected patients on failing antiretroviral therapy with evidence of resistance to currently available NNRTIs and at least three primary protease inhibitor mutations were eligible for enrolment if on stable (8 weeks unchanged) antiretroviral therapy with plasma HIV-1 RNA greater than 5000 copies per mL. Patients were randomly assigned to receive either TMC125 (200 mg) or placebo, each given twice daily with darunavir-ritonavir, investigator-selected nucleoside/nucleotide reverse transcriptase inhibitors, and optional enfuvirtide. The primary endpoint was the proportion of patients with confirmed viral load below 50 copies per mL at week 24 (FDA time-to-loss of virological response algorithm). Analyses were by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00255099.

FINDINGS

591 patients were randomised and treated (295 patients in the TMC125 group and 296 in the placebo group). By week 24, 51 (17%) patients in the TMC125 group and 73 (25%) in the placebo group had discontinued, mainly because of virological failure. 183 (62%) patients in the TMC125 group and 129 (44%) in the placebo group achieved confirmed viral load below 50 copies per mL at week 24 (difference 18%, 95% CI 11-26; p=0.0003). The type and frequency of adverse events were much the same in the two groups.

INTERPRETATION

In treatment-experienced patients, treatment with TMC125 led to better virological suppression at week 24 than did placebo. The safety and tolerability profile of TMC125 was generally comparable with placebo.

Pretreatment Factors Associated With 3-Year (144-Week) Virologic and Immunologic Responses to Potent Antiretroviral Therapy

OBJECTIVE

To examine pretreatment factors associated with longer term (144 weeks) responses to antiretroviral therapy (ART).

METHODS

Of 1498 ART-naive subjects randomized to ART regimens, including > or =3 agents, 1083 patients who had plasma HIV RNA (vRNA) levels and CD4 cell counts at baseline and week 144 were analyzed. Primary baseline factors evaluated were CD4 cell count, vRNA level, gender, race, and age, using multivariable Cox, log-binomial, and linear regression models.

RESULTS

Shorter time to achieving a vRNA level <50 copies/mL was associated with lower baseline vRNA level (P < 0.001), older age (P = 0.007), and lower baseline CD4 cell count (P = 0.055). After adjusting for race, gender, and baseline CD4 cell count, older age was associated with a vRNA level <50 copies/mL at week 144 (P = 0.018). Greater CD4 count increases from baseline to week 144 (mean = 284 cells/microL) were seen in younger men, blacks, and subjects with higher pretreatment vRNA levels; the effect of pretreatment vRNA level was most apparent in women.

CONCLUSIONS

Older age was the most important baseline predictor of a vRNA level <50 copies/mL at week 144; lower pretreatment vRNA level and older age were the most important predictors of time to a vRNA level <50 copies/mL. The influence of pretreatment factors on increases in CD4 cell counts differed between men and women.