Reverse Transcriptase Inhibitor Backbone Research Articles

2.0 Recommendations and auditable outcomes

2.0 Recommendations and auditable outcomes

Outcomes by sex following treatment initiation with atazanavir plus ritonavir or efavirenz with abacavir/lamivudine or tenofovir/emtricitabine.

We aimed to evaluate treatment responses to atazanavir plus ritonavir (ATV/r) or efavirenz (EFV) in initial antiretroviral regimens among women and men, and determine if treatment outcomes differ by sex. We performed a randomized trial of open-label ATV/r or EFV combined with abacavir/lamivudine (ABC/3TC) or tenofovir/emtricitabine (TDF/FTC) in 1857 human immunodeficiency virus type 1-infected, treatment-naive persons enrolled between September 2005 and November 2007 at 59 sites in the United States and Puerto Rico. Associations of sex with 3 primary study endpoints of time to virologic failure, safety, and tolerability events were analyzed using Cox proportional hazards models. Model-based population pharmacokinetic analysis was performed using nonlinear mixed effects modeling (NONMEM version VII). Of 1857 participants, 322 were women. Women assigned to ATV/r had a higher risk of virologic failure with either nucleoside reverse transcriptase inhibitor backbone than women assigned to EFV, or men assigned to ATV/r. The effects of ATV/r and EFV upon safety and tolerability risk did not differ significantly by sex. With ABC/3TC, women had a significantly higher (32%) safety risk compared to men; with TDF/FTC, the safety risk was 20% larger for women compared to men, but not statistically significant. Women had slower ATV clearance and higher predose levels of ATV compared to men. Self-reported adherence did not differ significantly by sex. This is the first randomized clinical trial to identify a significantly earlier time to virologic failure in women randomized to ATV/r compared to women randomized to EFV. This finding has important clinical implications given that boosted protease inhibitors are often favored over EFV in women of childbearing potential. NCT00118898.

Autonomic Neuropathy in HIV is Unrecognized and Associated with Medical Morbidity

Autonomic dysfunction is common in HIV. However, its clinical impact is not well understood and its protean symptoms make it difficult to diagnose. We sought to determine: (1) whether autonomic neuropathy is associated with morbidity and predicted mortality in HIV as measured by the Veterans Aging Cohort Study (VACS) index; and (2) if healthcare providers recognize the diagnosis of autonomic neuropathy. Data were obtained from 102 HIV-infected adults enrolled in a prevalence study of autonomic dysfunction from 2011-2012. Participants were predominantly minority with nearly equal numbers of men and women. Most were receiving an antiretroviral regimen with a nucleoside reverse transcriptase inhibitor backbone and a base of a non-nucleoside reverse transcriptase inhibitor, protease inhibitor, or integrase inhibitor. Autonomic neuropathy was defined using a laboratory-based autonomic assessment, the Composite Autonomic Severity Score (CASS). Medical records were reviewed for the year prior to the autonomic assessment. We found that the autonomic neuropathy score (CASS) was associated with the VACS index. We also found that among 53 participants with symptomatic autonomic neuropathy, the diagnosis had been considered for only one. The majority of the symptoms were either unexplained or attributed to medication side effects. This study demonstrates that autonomic neuropathy in HIV is associated with serious co-morbid illnesses known to increase mortality risk, and that HIV healthcare providers rarely consider autonomic neuropathy in their differential diagnoses. Future studies are needed to determine if autonomic neuropathy is an independent risk factor for mortality in HIV, and to raise awareness of its signs and symptoms.

Dolutegravir in antiretroviral-naive adults with HIV-1

Objective:To evaluate the efficacy and safety/tolerability of dolutegravir (DTG, S/GSK1349572), a potent inhibitor of HIV integrase, through the full 96 weeks of the SPRING-1 study.Design:ING112276 (SPRING-1) was a 96-week, randomized, partially blinded, phase IIb dose-ranging study.Methods:Treatment-naive adults with HIV received DTG 10, 25, or 50 mg once daily or efavirenz (EFV) 600 mg once daily (control arm) combined with investigator-selected dual nucleos(t)ide reverse transcriptase inhibitor backbone regimen (tenofovir/emtricitabine or abacavir/lamivudine). The primary endpoint of the study was the proportion of participants with plasma HIV-1 RNA less than 50 copies/ml, based on time to loss of virologic response at 16 weeks (conducted for the purpose of phase III dose selection), with a planned analysis at 96 weeks. Safety and tolerability were also assessed.Results:Of 208 participants randomized to treatment, 205 received study drug. At week 96, the proportion of participants achieving plasma HIV-1 RNA less than 50 copies/ml was 79, 78, and 88% for DTG 10, 25, and 50 mg, respectively, compared with 72% for EFV. The median increase from baseline in CD4+ cells was 338 cells/μl with DTG (all treatment groups combined) compared with 301 cells/μl with EFV (P = 0.155). No clinically significant dose-related trends in adverse events were observed, and fewer participants who received DTG withdrew because of adverse events (3%) compared with EFV (10%).Conclusion:Throughout the 96 weeks of the SPRING-1 study, DTG demonstrated sustained efficacy and favorable safety/tolerability in treatment-naive individuals with HIV-1.

Suboptimal Suppression with Maraviroc plus a Boosted Protease Inhibitor

A nucleoside reverse transcriptase inhibitor (NRTI) backbone remains standard in combination antiretroviral therapy, but there is ongoing interest in developing NRTI-sparing regimens to avoid the drugs' short- and long-term toxicities. In a recent multinational, open-label, manufacturer-sponsored trial, 121 treatment-naive HIV-infected individuals with confirmed CCR5-tropic virus were randomized to receive ritonavir-boosted atazanavir in combination with either tenofovir/FTC or …

SWIFT: prospective 48-week study to evaluate efficacy and safety of switching to emtricitabine/tenofovir from lamivudine/abacavir in virologically suppressed HIV-1 infected patients on a boosted protease inhibitor containing antiretroviral regimen.

In the United States, emtricitabine/tenofovir disoproxil fumarate (FTC/TDF) is a preferred nucleoside reverse transcriptase inhibitor (NRTI) backbone with lamivudine/abacavir (3TC/ABC) as a commonly used alternative. For patients infected with human immunodeficiency virus (HIV-1) virologically suppressed on a boosted protease inhibitor (PI) + 3TC/ABC regimen, the merits of switching to FTC/TDF as the NRTI backbone are unknown. SWIFT was a prospective, randomized, open-label 48-week study to evaluate efficacy and safety of switching to FTC/TDF. Subjects receiving 3TC/ABC + PI + ritonavir (RTV) with HIV-1 RNA < 200 c/mL ≥3 months were randomized to continue 3TC/ABC or switch to FTC/TDF. The primary endpoint was time to loss of virologic response (TLOVR) with noninferiority measured by delta of 12%. Virologic failure (VF) was defined as confirmed rebound or the last HIV-1 RNA measurement on study drug ≥200 c/mL. In total, 311 subjects were treated in this study (155 to PI + RTV + FTC/TDF, 156 to PI + RTV + 3TC/ABC). Baseline characteristics were similar between the arms: 85% male, 28% black, median age, 46 years; and median CD4 532 cells/mm(3). By TLOVR through week 48, switching to FTC/TDF was noninferior compared to continued 3TC/ABC (86.4% vs 83.3%, treatment difference 3.0% (95% confidence interval, -5.1% to 11.2%). Fewer subjects on FTC/TDF experienced VF (3 vs 11; P = .034). FTC/TDF showed greater declines in fasting low-density lipoproteins (LDL), total cholesterol (TC), and triglycerides (TG) with significant declines in LDL and TC beginning at week 12 with no TC/HDL ratio change. Switching to FTC/TDF showed improved NCEP thresholds for TC and TG and improved 10-year Framingham TC calculated scores. Decreased estimated glomerular filtration rate [corrected] (eGFR) was observed in both arms with a larger decrease in the FTC/TDF arm. Switching to FTC/TDF from 3TC/ABC maintained virologic suppression, had fewer VFs, improved lipid parameters and Framingham scores but decreased eGFR. CLINICALTRIALS.GOV IDENTIFIER: NCT00724711.

Once-daily dolutegravir versus raltegravir in antiretroviral-naive adults with HIV-1 infection: 48 week results from the randomised, double-blind, non-inferiority SPRING-2 study

Dolutegravir (S/GSK1349572) is a once-daily HIV integrase inhibitor with potent antiviral activity and a favourable safety profile. We compared dolutegravir with HIV integrase inhibitor raltegravir, as initial treatment for adults with HIV-1. SPRING-2 is a 96 week, phase 3, randomised, double-blind, active-controlled, non-inferiority study that began on Oct 19, 2010, at 100 sites in Canada, USA, Australia, and Europe. Treatment-naive adults (aged ≥ 18 years) with HIV-1 infection and HIV-1 RNA concentrations of 1000 copies per mL or greater were randomly assigned (1:1) via a computer-generated randomisation sequence to receive either dolutegravir (50 mg once daily) or raltegravir (400 mg twice daily). Study drugs were given with coformulated tenofovir/emtricitabine or abacavir/lamivudine. Randomisation was stratified by screening HIV-1 RNA (≤ 100,000 copies per mL or >100,000 copies per mL) and nucleoside reverse transcriptase inhibitor backbone. Investigators were not masked to HIV-1 RNA results before randomisation. The primary endpoint was the proportion of participants with HIV-1 RNA less than 50 copies per mL at 48 weeks, with a 10% non-inferiority margin. Main secondary endpoints were changes from baseline in CD4 cell counts, incidence and severity of adverse events, changes in laboratory parameters, and genotypic or phenotypic evidence of resistance. Our primary analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01227824. 411 patients were randomly allocated to receive dolutegravir and 411 to receive raltegravir and received at least one dose of study drug. At 48 weeks, 361 (88%) patients in the dolutegravir group achieved an HIV-1 RNA value of less than 50 copies per mL compared with 351 (85%) in the raltegravir group (adjusted difference 2·5%; 95% CI -2·2 to 7·1). Adverse events were similar between treatment groups. The most common events were nausea (59 [14%] patients in the dolutegravir group vs 53 [13%] in the raltegravir group), headache (51 [12%] vs 48 [12%]), nasopharyngitis (46 [11%] vs 48 [12%]), and diarrhoea (47 [11%] in each group). Few patients had drug-related serious adverse events (three [<1%] vs five [1%]), and few had adverse events leading to discontinuation (ten [2%] vs seven [2%] in each group). CD4 cell counts increased from baseline to week 48 in both treatment groups by a median of 230 cells per μL. Rates of graded laboratory toxic effects were similar. We noted no evidence of treatment-emergent resistance in patients with virological failure on dolutegravir, whereas of the patients with virologic failure who received raltegravir, one (6%) had integrase treatment-emergent resistance and four (21%) had nucleoside reverse transcriptase inhibitors treatment-emergent resistance. The non-inferior efficacy and similar safety profile of dolutegravir compared with raltegravir means that if approved, combination treatment with once-daily dolutegravir and fixed-dose nucleoside reverse transcriptase inhibitors would be an effective new option for treatment of HIV-1 in treatment-naive patients. ViiV Healthcare.

Análisis comparativo de coste-eficacia entre darunavir/ritonavir y otros inhibidores de la proteasa en el tratamiento de la infección por el virus de la inmunodeficiencia humana de tipo 1 en pacientes naïve en España

IntroductionGESIDA (AIDS Study Group) has proposed preferred regimens of antiretroviral treatment as initial therapy in HIV infected patients. The objective of this analysis is to compare the costs and effectiveness of darunavir/r QD and other ritonavir-boosted (/r) protease inhibitors (PIs) currently recommended in GESIDA guidelines for treatment-naïve patients. MethodsA cost-efficacy model compared the boosted PIs recommended as preferred or alternative treatment choices, each used with a nucleoside reverse transcriptase inhibitor backbone. Efficacy was measured by 48-week virological response (viral load < 50 copies/mL) adjusted by baseline viral load and CD4 cell count. To generate efficiency frontiers and cost-efficacy ratios, one-year antiretroviral therapy costs in Spain, and 48-week efficacy values were used. ResultsThe model estimated that starting treatment with darunavir/r QD was the most cost-effective choice compared with the other preferred PI/r based therapies. The average cost per patient with a virological response was lower for darunavir/r QD (13,420€) than for atazanavir/r QD (14,000€), or lopinavir/r BID (13,815€). Among the preferred PI/r-based therapies, darunavir/r QD also was estimated to be the most efficient option for treatment-naïve patients. Atazanavir/r QD and lopinavir/r BID were found to be «dominated» by darunavir/r) and, consequently, were outside the efficiency frontier of PI/r-based first-line treatment. Given a fixed budget of 10 million euros for PI/r-based first-line therapy, the model estimated that darunavir/r QD would yield more responders (745) than atazanavir/r QD (714), or lopinavir/r BID (724). At the same time, darunavir/r QD would reduce the number of individuals failing treatment (150) compared with atazanavir/r QD (172) and lopinavir/r BID (286). ConclusionsIn this model, darunavir/r QD was found to be the most cost-effective choice, among the preferred PI/r-based therapies recommended in the Spanish guidelines for treatment-naïve patients.

Impact of baseline HIV‐1 RNA levels on initial highly active antiretroviral therapy outcome: a meta‐analysis of 12,370 patients in 21 clinical trials*

Individual randomized trials of first-line antiretroviral treatment do not consistently show an association between higher baseline HIV-1 RNA and lower efficacy. A MEDLINE search identified 21 HIV clinical trials with published analyses of antiretroviral efficacy by baseline HIV-1 RNA, using a standardized efficacy endpoint of HIV-1 RNA suppression <50 copies/mL at week 48. Among 21 clinical trials identified, eight evaluated only nonnucleoside reverse transcriptase inhibitor (NNRTI)-based combinations, eight evaluated only protease inhibitor-based regimens and five compared different treatment classes. Ten of the trials included tenofovir (TDF)/emtricitabine (FTC) as only nucleoside reverse transcriptase inhibitor (NRTI) backbone, in addition but not restricted to abacavir (ABC)/lamivudine (3TC) (n = 7), zidovudine (ZDV)/3TC (n = 4) and stavudine (d4T)/3TC (n = 1). Across trials, the mean percentage of patients achieving HIV-1 RNA < 50 copies/mL at week 48 was 81.5% (5322 of 6814) for patients with baseline HIV-1 RNA < 100 000, vs. 72.6% (3949 of 5556) for patients with HIV-1 RNA > 100 000 copies/mL. In the meta-analysis, the absolute difference in efficacy between low and high HIV-1 RNA subgroups was 7.4% [95% confidence interval (CI) 5.9-8.9%; P < 0.001]. This difference was consistent in trials of NNRTI-based treatments (difference = 6.9%; 95% CI 4.3-9.6%), protease inhibitor-based treatments (difference = 8.4%; 95% CI 6.0-10.8%) and integrase or chemokine (C-C motif) receptor 5 (CCR5)-based treatments (difference = 6.0%; 95% CI 2.1-9.9%) and for trials using TDF/FTC (difference = 8.4%; 95% CI 6.0-10.8%); there was no evidence for heterogeneity of this difference between trials (Cochran's Q test; not significant). In this meta-analysis of 21 first-line clinical trials, rates of HIV-1 RNA suppression at week 48 were significantly lower for patients w ith baseline HIV-1 RNA > 100 000 copies/mL (P < 0.001). This difference in efficacy was consistent across trials of different treatment classes and NRTI backbones.

Safety and efficacy of a raltegravir‐based dual antiretroviral therapy in clinical practice

BackgroundHAART has revolutionized HIV disease management and increased life expectancy for most HIV‐infected individuals on treatment. A nucleoside/tide reverse transcriptase (NRTI) inhibitor backbone is a recommended component of standard first‐line HAART. Nevertheless, NRTI‐sparing alternatives are warranted in order to reduce long‐term toxicities in many patients (pts). Aim of the study was to evaluate safety of raltegravir‐based dual antiretroviral therapy (DUAL) in a clinical practice setting.MethodsAll pts on DUAL regimen followed at our outpatient HIV service on May 31st 2012 were recruited. Their clinical files were retrospectively studied. Collected data included: demographics, CDC staging, reason to DUAL switching, cholesterol (total and HDL), creatinine, CK, CD4+ count and HIV RNA were recorded at switch and every six months after for the first year. Change in CD4 count after the switch was evaluated by Student t‐test.ResultsThe cohort included 55 pts (27 M); mean age was 54 years (38–72). HIV infection was acquired through: injective drug abuse (25), unprotected homosexual (24) and heterosexual (16) intercourse. CDC staging was: A=16, B=26, C=13. Mean previous treatment regimens were 4. At time of study pts had been on DUAL regimen for 23 months. They had been switched to DUAL therapy for: drug resistance (14; 25.5%) (DRR) or drug toxicity (41; 74.5%). The most frequently associated drug was darunavir/rtv (19; 34.5%), followed by atazanavir (13; 23.6%; 5 were unboosted); lopinavir/rtv (12; 21.8%), and NVP (11; 20%). DRR pts presented at baseline a mean viral load of 40,153 copies of HIV‐RNA/ml; after at 12 months all but 3 showed undetectable (&lt;40 copies) viral load and a mean CD4 gain of 142 cells/ml. Pts switched to DUAL for toxicity presented persistent undetectable viral load and a mean CD4+gain of 94 cells/ml. The observed CD4+ increase in both groups (DRR and toxicity) presented a statistical significance (p&lt;0.01). Total and HDL cholesterol, and creatinine did not present significant variations. CK remained stable and no toxicity episode was observed.ConclusionDUAL approach showed good safety and also remarkable results in terms of viral suppression and immunological recovery. Notwithstanding the potential low genetic barrier of some combinations (e.g. NVP+RAL) this strategy demonstrated to be effective. The long term reliability of DUAL should be confirmed by studies with a longer follow up and a wider sample.

Are we conSTRucting the best treatment regimens for all patients with HIV infection?

The British HIV Association (BHIVA) 2012 guidelines for the treatment of HIV recommend patients start combination antiretroviral therapy (ART) containing tenofovir and emtricitabine as the nucleos(t)ide reverse transcriptase inhibitor (NRTI) backbone. BHIVA third agent preferred choices comprise efavirenz, boosted atazanavir, boosted darunavir and raltegravir, and the guidelines further state that ‘fixed dose combinations (FDC) of drugs can increase adherence’ [1]. Atripla is currently the only available single-tablet regimen (STR) for the treatment of HIV which contains a combination of BHIVA preferred first-line antiretrovirals (tenofovir, emtricitabine and efavirenz). In addition, studies have shown that Atripla can improve adherence, treatment satisfaction and outcomes for patients infected with HIV [2]. A retrospective case note review was conducted for all HIV-positive patients attending a UK HIV centre and receiving ART. The purpose was to ascertain the proportion of patients receiving BHIVA preferred ART in its simplest dosing format (in this case Atripla) and to investigate whether there were clinically or virologically appropriate reasons why patients not on Atripla were prescribed more complex drug regimens. The total number of patients receiving ART at the time of review was 142, of which 47 (33%) were currently taking Atripla. Of the remaining 95 patients, 30 (32%) had taken Atripla or some of its components in the past and been changed from this for valid clinical or virological reasons. In addition, there were a further 34 cases (36%) where Atripla had never been offered to the patient for appropriate reasons and documentation of 8 instances in which Atripla had been declined by the patient. There remained, however, 28 cases (29%) where there was no documentation of Atripla having been considered or offered, and no apparent contraindications to the STR or its components. This included 4 patients with an elevated cardiovascular risk, all of whom were taking an abacavir-containing ART regimen at the time of review. Despite extensive professional guidance on preferred ART regimens and evidence to suggest that STR can increase adherence and patient satisfaction there remain patients in clinical care taking more complex drug regimens with no clear indication for this. We would encourage physicians to identify such patients and to discuss with them their treatment options in the light of advances in ART combination preparations.

5.0 What to start

5.0 What to start

A Randomized Trial of Raltegravir Replacement for Protease Inhibitor or Non-Nucleoside Reverse Transcriptase Inhibitor in HIV-Infected Women with Lipohypertrophy

Lipohypertrophy in HIV-infected patients is associated with metabolic abnormalities. Raltegravir (RAL) is not known to induce fat changes or severe metabolic perturbations. HIV-infected women with central adiposity and HIV-1 RNA less than 50 copies per milliliter on non-nucleoside reverse transcriptase inhibitor (NNRTI)- or protease inhibitor (PI)-based antiretroviral therapy (ART) continued their nucleoside reverse transcriptase inhibitor (NRTI) backbone and were randomized to switch to open label RAL immediately or after 24 weeks. The primary end point was 24-week between-group change in computed tomography (CT)-quantified visceral adipose tissue (AT) volume. Fasting lipids, glucose, C-reactive protein (CRP), anthropometric measurements, and patient-reported quality of life assessments were also measured. Thirty-six subjects provided 80% power to detect a 10% between-group difference in visceral AT over 24 weeks. Thirty-seven of 39 enrolled subjects completed week 24. At entry, subjects were 75% black or Hispanic, and on 62% PI-based and 38% NNRTI-based regimens. The median age was 43 years, CD4 count 558 cells per microliter, and body mass index (BMI) 32 kg/m(2). After 24 weeks, no statistically significant changes in visceral or subcutaneous AT, anthropometrics, BMI, glucose, or CRP were observed. In subjects receiving RAL, significant improvements in total and LDL cholesterol (p=0.04), self-reported belly size (p=0.02) and composite body size (p=0.02) were observed. Body size changes correlated well with percent visceral AT change. No RAL-related adverse events occurred. Compared to continued PI or NNRTI, switch to RAL was associated with statistically significant 24-week improvements in total and LDL cholesterol but not AT volumes. Additional insights into AT and metabolic changes in women on RAL will be provided by 48-week follow-up of the immediate-switch arm.

A Switch in Therapy to a Reverse Transcriptase Inhibitor Sparing Combination of Lopinavir/Ritonavir and Raltegravir in Virologically Suppressed HIV-Infected Patients: A Pilot Randomized Trial to Assess Efficacy and Safety Profile: The KITE Study

A nucleoside reverse transcriptase inhibitor (NRTI) backbone is a recommended component of standard highly active antiretroviral therapy (sHAART). However, long-term NRTI exposure can be limited by toxicities. NRTI class-sparing alternatives are warranted in select patient populations. This is a 48-week single-center, open-label pilot study in which 60 HIV-infected adults with plasma HIV-1 RNA (<50 copies/ml) on sHAART were randomized (2:1) to lopinavir/ritonavir (LPV/r) 400/100 mg BID+raltegravir (RAL) 400 mg BID switch (LPV-r/RAL arm) or to continue on sHAART. The primary endpoint was the proportion of subjects with HIV-RNA<50 copies/ml at week 48. Secondary efficacy and immunologic and safety endpoints were evaluated. Demographics and baseline lipid profile were similar across arms. Mean entry CD4 T cell count was 493 cells/mm(3). At week 48, 92% [95% confidence interval (CI): 83-100%] of the LPV-r/RAL arm and 88% (95% CI: 75-100%) of the sHAART arm had HIV-RNA<50 copies/ml (p=0.70). Lipid profile (mean ± SEM, mg/dl, LPV-r/RAL vs. sHAART) at week 24 was total-cholesterol 194 ± 5 vs. 176 ± 9 (p=0.07), triglycerides 234 ± 30 vs. 133 ± 27 (p=0.003), and LDL-cholesterol 121 ± 6 vs. 110 ± 8 (p=0.27). There were no serious adverse events (AEs) in either arm. Regimen change occurred in three LPV-r/RAL subjects (n=1, due to LPV-r/RAL-related AEs) vs. 0 in sHAART. There were no differences between arms in bone mineral density, total body fat composition, creatinine clearance, or CD4 T cell counts at week 48. In virologically suppressed patients on HAART, switching therapy to the NRTI-sparing LPV-r/RAL combination produced similar sustained virologic suppression and immunologic profile as sHAART. AEs were comparable between arms, but the LPV-r/RAL arm experienced higher triglyceridemia.

Patterns of HIV-1 Drug Resistance After First-Line Antiretroviral Therapy (ART) Failure in 6 Sub-Saharan African Countries: Implications for Second-Line ART Strategies

Human immunodeficiency virus type 1 (HIV-1) drug resistance may limit the benefits of antiretroviral therapy (ART). This cohort study examined patterns of drug-resistance mutations (DRMs) in individuals with virological failure on first-line ART at 13 clinical sites in 6 African countries and predicted their impact on second-line drug susceptibility. A total of 2588 antiretroviral-naive individuals initiated ART consisting of different nucleoside reverse transcriptase inhibitor (NRTI) backbones (zidovudine, stavudine, tenofovir, or abacavir, plus lamivudine or emtricitabine) with either efavirenz or nevirapine. Population sequencing after 12 months of ART was retrospectively performed if HIV RNA was >1000 copies/mL. The 2010 International Antiviral Society-USA list was used to score major DRMs. The Stanford algorithm was used to predict drug susceptibility. HIV-1 sequences were generated for 142 participants who virologically failed ART, of whom 70% carried ≥1 DRM and 49% had dual-class resistance, with an average of 2.4 DRMs per sequence (range, 1-8). The most common DRMs were M184V (53.5%), K103N (28.9%), Y181C (15.5%), and G190A (14.1%). Thymidine analogue mutations were present in 8.5%. K65R was frequently selected by stavudine (15.0%) or tenofovir (27.7%). Among participants with ≥1 DRM, HIV-1 susceptibility was reduced in 93% for efavirenz/nevirapine, in 81% for lamivudine/emtricitabine, in 59% for etravirine/rilpivirine, in 27% for tenofovir, in 18% for stavudine, and in 10% for zidovudine. Early failure detection limited the accumulation of resistance. After stavudine failure in African populations, zidovudine rather than tenofovir may be preferred in second-line ART. Strategies to prevent HIV-1 resistance are a global priority.

Spillover adherence effects of fixed-dose combination HIV therapy

The impact of fixed-dose combination (FDC) products on adherence to other, non-fixed regimen components has not been examined. We compared adherence to a third antiretroviral (ART) component among patients receiving a nucleoside reverse transcriptase inhibitor (NRTI) backbone consisting of the FDC Epzicom®, GlaxoSmithKline Inc, Research Triangle Park, NC (abacavir sulfate 600 mg + lamivudine 300 mg; FDC group) versus NRTI combinations taken as two separate pills (NRTI Combo group) using data from a national sample of 30 health plans covering approximately 38 million lives from 1997 to 2005. Adherence was measured as the medication possession ratio (MPR). Multivariate logistic regression compared treatment groups based on the likelihood of achieving ≥95% adherence, with sensitivity analyses using alternative thresholds. MPR was assessed as a continuous variable using multivariate linear regression. Covariates included age, gender, insurance payer type, year of study drug initiation, presence of mental health and substance abuse disorders, and third agent class. The study sample consisted of 650 FDC and 1947 NRTI Combo patients. Unadjusted mean adherence to the third agent was higher in the FDC group than the NRTI Combo group (0.92 vs 0.85; P < 0.0001). In regression analyses, FDC patients were 48% and 39% more likely to achieve 95% and 90% third agent adherence, respectively (P ≤ 0.03). None of the other MPR specifications achieved comparable results. Among managed care patients, use of an FDC appears to substantially improve adherence to a third regimen component and thus the likelihood of achieving the accepted standard for adherence to HIV therapy of 95%.

Abacavir versus other nucleoside reverse transcriptase inhibitor (NRTI) backbone therapies for treatment of HIV infection

Abacavir versus other nucleoside reverse transcriptase inhibitor (NRTI) backbone therapies for treatment of HIV infection

Effect of accompanying antiretroviral drugs on virological response to pegylated interferon and ribavirin in patients co-infected with HIV and hepatitis C virus

The effects of antiretroviral drugs on the response to pegylated interferon plus ribavirin remain uncertain. We evaluated whether antiretroviral drugs affected the response to pegylated interferon plus ribavirin in patients co-infected with HIV and hepatitis C virus (HCV). We conducted a retrospective analysis of two cohorts of HIV/HCV-co-infected patients treated with pegylated interferon plus ribavirin between 2001 and 2007 in Spain. The outcome measure was sustained virological response (SVR). Logistic regression models were used to test possible associations between non-response and pre-treatment characteristics, including accompanying antiretroviral drugs. The study sample comprised 1701 patients: 63% were infected with HCV genotype (G) 1 or 4 and 88% were taking highly active antiretroviral therapy (HAART). Factors independently associated with increased odds of SVR were G2 or 3, HVC RNA <500,000 IU/mL and CDC clinical category A or B. When we adjusted for these prognostic factors and dose of ribavirin/kg, the adjusted odds ratio (AOR) of SVR for patients without HAART was 1.31 [95% confidence interval (CI) 0.91-1.88; P = 0.144]. Taking the backbone of tenofovir and lamivudine/emtricitabine as a reference, we found that, with the exception of regimens including zidovudine, the effect of other nucleoside reverse transcriptase inhibitor backbones had little effect on SVR. The AOR of SVR for zidovudine and lamivudine was 0.65 (95% CI 0.46-0.93, P = 0.017). We carried out several sensitivity analyses, the results of which were consistent with the findings of the primary analysis. Our results suggest that, with the exception of regimens including zidovudine, accompanying antiretroviral drugs have little effect on the virological response to pegylated interferon plus ribavirin in HIV/HCV-co-infected patients.

Management of HIV infection in treatment-naive patients: a review of the most current recommendations.

The most current guidelines issued by the Department of Health and Human Services (DHHS) on the management of human immunodeficiency virus (HIV) infection in treatment-naive patients are reviewed. Treatment guidelines are updated frequently because of the emergence of data demonstrating the risks and benefits of antiretroviral therapy. The DHHS guidelines strongly recommend initiating therapy in patients with certain conditions regardless of CD4 cell count and in patients with CD4 cell counts of <350 cells/mm(3). Although supporting data are less definitive, treatment is also recommended for patients with CD4 cell counts of 350-500 cells/mm(3). Treatment for patients with CD4 cell counts of >500 cells/mm(3) is controversial. Although cumulative observational data and biological evidence support treatment at higher CD4 cell counts, randomized controlled trial data to support this are not available, and the risk of antiretroviral toxicities, resistance, non-adherence, and cost should be considered in individual patients. The preferred regimens have been consolidated to four options, including a dual-nucleoside reverse transcriptase inhibitor backbone (tenofovir plus emtricitabine) with a nonnucleoside reverse transcriptase inhibitor (efavirenz), a ritonavir-boosted protease inhibitor (atazanavir plus ritonavir or darunavir plus ritonavir), or an integrase strand-transfer inhibitor (raltegravir). Regimens are classified as alternative or acceptable when they have potential safety or efficacy concerns, have higher pill burdens, or require more-frequent administration compared with preferred regimens. The DHHS 2011 guidelines advocate earlier antiretroviral therapy initiation than recommended in recent years, and preferred regimens have been refined to maximize efficacy, safety, and quality of life for treatment-naive HIV-infected patients.

Comparative Cost-Efficacy Analysis of Darunavir/ritonavir and Other Ritonavir-Boosted Protease Inhibitors for First-Line Treatment of HIV-1 Infection in the United States

Purpose: A comprehensive study comparing the costs and efficacies of darunavir/ritonavir 800/100 mg qd and the other ritonavir-boosted (/r) protease inhibitors (PIs) recommended for treatment-naïve individuals with HIV-1 infection would help health care decision makers identify the value of each boosted PI. Methods: A cost-efficacy model was developed to compare the five recommended boosted PIs, each used with a tenofovir-based nucleotide/nucleoside reverse transcriptase inhibitor backbone. Efficacy was measured by virologic response (ie, HIV-1 ribonucleic acid < 50 copies/mL) at 48 weeks, based on a systematic review and meta-analysis of recent clinical trials. One-year antiretroviral therapy costs and 48-week efficacy values were used to generate the efficiency frontier and cost-efficacy ratios. Results: Darunavir/r was the most efficacious boosted PI, with an incremental cost-efficacy ratio of $27,390 per additional individual with virologic response, compared with fosamprenavir/r. All other regimens were dominated. Darunavir/r combination therapy also had one of the lowest average costs ($26,287) per individual with virologic response, resulting in a maximal number of individuals successfully treated within a fixed budget. The model results were robust in variability and sensitivity analyses. Conclusion: Darunavir/r 800/100 mg qd combination therapy represents a cost-efficacious option for treatment-naïve individuals with HIV-1 infection in the United States.