Impact of pre-antiretroviral treatment HIV-RNA on time to successful virological suppression and subsequent virological failure - two nationwide, population-based cohort studies

BACKGROUND

The impact of pre-antiretroviral treatment (ART) HIV-RNA on time to successful virological suppression and subsequent failure in HIV patients remains poorly investigated.

METHODS

We used the Swedish InfCareHIV database and the Danish HIV Cohort Study to evaluate impact of pre-ART HIV-RNA on primary virological suppression (HIV-RNA < 50 copies/ml) and risk of secondary virological failure (two consecutive HIV-RNA > 200 copies/ml or one >1000 copies/ml). The study included 3366 Swedish and 2050 Danish ART naïve individuals who initiated ART in the period 2000-2018. We used Kaplan-Meier estimates and Cox regression analyses to estimate absolute risks and hazard ratios.

RESULTS

In both cohorts, more than 95% of patients with a pre-ART HIV-RNA <100 000 copies/ml obtained virological suppression within the first year after ART initiation contrasting 74% (Sweden) and 86% (Denmark) in those with HIV-RNA >1 000 000 copies/ml. Almost all patients obtained virological suppression after four years irrespective of pre-ART HIV-RNA. In contrast, we observed no substantial impact of pre-ART HIV-RNA on risk of virological failure once virological suppression was obtained.

CONCLUSION

High pre-ART HIV-RNA is strongly associated with increased time to successful virological suppression, but pre-ART HIV-RNA has no impact on risk of subsequent virological failure.

Long-term treatment with atazanavir (ATV) in real life in Belgium: a retrospective observational cohort of 2264 HIV patients. Acta Clin Belg 2019;74:143-150. [PMID: 29718781 DOI: 10.1080/17843286.2018.1462753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

OBJECTIVES

This 5-year follow-up study aimed to assess clinical outcomes of HIV-1 infected adults treated with atazanavir (ATV) in clinical practice in Belgium, to describe patient profiles and characteristics, as well as treatment safety.

METHODS

A multicenter, non-interventional, non-comparative, retrospective cohort study was performed in HIV-1 positive adult patients treated with ATV between 2006 and 2012. Data were collected from 8 AIDS reference centers' databases. All analyses were on-treatment. Sub-analyses were carried out in unboosted ATV treated patients and in females. The primary endpoint was defined as the time-to-treatment-discontinuation. Furthermore, virological suppression, immunological response, time to loss of virological response, reasons for ATV initiation, and discontinuation were also assessed.

RESULTS

2264 ARV-naive and ARV-experienced patients (median age: 41 years) were included. Females and non-Caucasians were broadly represented (40 and 45%, respectively). The probability to remain on treatment was 0.78 (CI: 0.76; 0.78) for the first and 0.69 (CI: 0.66; 0.71) for the second year and was similar between males and females. Overall, 771 patients (34.1%) discontinued ATV over time, the median (Q1-Q3) time to discontinuation being 0.8 (0.3-1.5) year. In unboosted ATV-treated patients, results were comparable to the overall ATV population, except for a higher rate of discontinuation-over-time (45.1%).

CONCLUSIONS

Clinical and safety data from this 5 year-cohort study show that the vast majority of patients remained on ATV treatment for the first and second years, overall as well as patients treated with unboosted ATV and females.

[Consensus Statement by GeSIDA/National AIDS Plan Secretariat on antiretroviral treatment in adults infected by the human immunodeficiency virus (Updated January 2013)]

OBJECTIVE

This consensus document is an update of combined antiretroviral therapy (cART) guidelines for HIV-1 infected adult patients.

METHODS

To formulate these recommendations a panel composed of members of the GeSIDA/National AIDS Plan Secretariat (Grupo de Estudio de Sida and the Secretaría del Plan Nacional sobre el Sida) reviewed the efficacy and safety advances in clinical trials, cohort and pharmacokinetic studies published in medical journals (PubMed and Embase) or presented in medical scientific meetings. The strength of the recommendations and the evidence which support them are based on a modification of the criteria of Infectious Diseases Society of America.

RESULTS

cART is recommended in patients with symptoms of HIV infection, in pregnant women, in serodiscordant couples with high risk of transmission, in hepatitisB co-infection requiring treatment, and in HIV nephropathy. cART is recommended in asymptomatic patients if CD4 is <500cells/μl. If CD4 are >500cells/μl cART should be considered in the case of chronic hepatitisC, cirrhosis, high cardiovascular risk, plasma viral load >100.000 copies/ml, proportion of CD4 cells <14%, neurocognitive deficits, and in people aged >55years. The objective of cART is to achieve an undetectable viral load. The first cART should include 2 reverse transcriptase inhibitors (RTI) nucleoside analogs and a third drug (a non-analog RTI, a ritonavir boosted protease inhibitor, or an integrase inhibitor). The panel has consensually selected some drug combinations, for the first cART and specific criteria for cART in acute HIV infection, in tuberculosis and other HIV related opportunistic infections, for the women and in pregnancy, in hepatitisB or C co-infection, in HIV-2 infection, and in post-exposure prophylaxis.

CONCLUSIONS

These new guidelines update previous recommendations related to first cART (when to begin and what drugs should be used), how to monitor, and what to do in case of viral failure or adverse drug reactions. cART specific criteria in comorbid patients and special situations are similarly updated.

[Comparative cost-effectiveness analysis between darunavir/ritonavir and other protease inhibitors in treatment-naive human immunodeficiency syndrome type 1-infected patients in Spain]

INTRODUCTION

GESIDA (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.

METHODS

A 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.

RESULTS

The 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).

CONCLUSIONS

In 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*

BACKGROUND

Individual randomized trials of first-line antiretroviral treatment do not consistently show an association between higher baseline HIV-1 RNA and lower efficacy.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

[Consensus document of Gesida and Spanish Secretariat for the National Plan on AIDS (SPNS) regarding combined antiretroviral treatment in adults infected by the human immunodeficiency virus (January 2012)]

This consensus document has been prepared by a panel consisting of members of the AIDS Study Group (Gesida) and the Spanish Secretariat for the National Plan on AIDS (SPNS) after reviewing the efficacy and safety results of clinical trials, cohort and pharmacokinetic studies published in medical journals, or presented in medical scientific meetings. Gesida has prepared an objective and structured method to prioritise combined antiretroviral treatment (cART) in naïve patients. Recommendations strength (A, B, C) and the evidence which supports them (I, II, III) are based on a modification of the Infectious Diseases Society of America criteria. The current antiretroviral treatment (ART) of choice for chronic HIV infection is the combination of three drugs. ART is recommended in patients with symptomatic HIV infection, in pregnancy, in serodiscordant couples with high transmission risk, hepatitis B fulfilling treatment criteria, and HIV nephropathy. Guidelines on ART treatment in patients with concurrent diagnosis of HIV infection and an opportunistic type C infection are included. In asymptomatic patients ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts <350 cells/μL; 2) when CD4 counts are between 350 and 500 cells/μL, therapy will be recommended and only delayed if patient is reluctant to take it, the CD4 are stabilised, and the plasma viral load is low; 3) therapy could be deferred when CD4 counts are above 500 cells/μL, but should be considered in cases of cirrhosis, chronic hepatitis C, high cardiovascular risk, plasma viral load >10(5) copies/mL, proportion of CD4 cells <14%, and in people aged >55 years. ART should include 2 reverse transcriptase inhibitors nucleoside analogues and a third drug (non-analogue reverse transcriptase inhibitor, ritonavir boosted protease inhibitor or integrase inhibitor). The panel has consensually selected and given priority to using the Gesida score for some drug combinations, some of them co-formulated. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures, but an undetectable viral load may be possible nowadays. Adverse events are a fading problem of ART. Guidelines in acute HIV infection, in women, in pregnancy, and to prevent mother-to-child transmission and pre- and post-exposition prophylaxis are commented upon. Management of hepatitis B or C co-infection, other co-morbidities, and the characteristics of ART in HIV-2 infection are included.

Atazanavir/ritonavir-based combination antiretroviral therapy for treatment of HIV-1 infection in adults

In the past 15 years, improvements in the management of HIV infection have dramatically reduced morbidity and mortality. Similarly, rapid advances in antiretroviral medications have resulted in the possibility of life-long therapy with simple and tolerable regimens. Protease inhibitors have been important medications in regimens of combination antiretroviral therapy for the treatment of HIV. One of the recommended and commonly used therapies in this class is once-daily-administered atazanavir, pharmacologically boosted with ritonavir (atazanavir/r). Clinical studies and practice have shown these drugs, in combination with other antiretroviral agents, to be potent, safe and easy to use in a variety of settings. Atazanavir/r has minimal short-term toxicity, including benign bilirubin elevation, and has less potential for long-term complications of hyperlipidemia and insulin resistance compared with other protease inhibitors. A high genetic barrier to resistance and a favorable resistance profile make it an excellent option for initial HIV treatment or as the first drug utilized in the protease inhibitors class. Atazanavir/r is also currently being studied in novel treatment strategies, including combinations with new classes of antiretrovirals to assess nucleoside reverse transcriptase inhibitor-sparing regimens. In this article we review atazanavir/r as a treatment for HIV infection and discuss the latest information on its pharmacology, efficacy and toxicity.

A pilot study of abacavir/lamivudine and raltegravir in antiretroviral-naïve HIV-1-infected patients: 48-week results of the SHIELD trial

PURPOSE

to evaluate raltegravir plus abacavir/lamivudine in antiretroviral-naïve, HIV-1-infected patients.

METHODS

SHIELD is an ongoing 96-week pilot study of abacavir/lamivudine 600 mg/300 mg once daily with raltegravir 400 mg twice daily among HLA-B*5701-negative adults with screening viral load (VL) > 1,000 copies/mL. HBsAg+ patients were excluded, as were patients with key mutation(s) to any study drug. Virologic failure (VF) was defined as either VL > 400 copies/mL at week 24 or confirmed virologic rebound.

RESULTS

thirty-five patients enrolled (mean age 38.7 years). Most were white males, but 26% self-identified as Hispanic/Latino. At baseline, 34% had VL ≥ 100,000 copies/mL (median, 4.8 log10 copies/mL) and 20% had CD4 cell counts <200 cells/mm3 (median, 301). One patient discontinued due to adverse events (AEs); one patient experienced VF. At week 48, 91% (32/35) had VL <50 and <400 copies/mL by missing/discontinuation equals failure analysis. Median CD4 cell count change from baseline was +247 cells/mm3. Five patients (14%) had treatment-related grade 2-4 AEs; no treatment-related serious AEs were reported. Over 48 weeks, median fasting lipids increased for total (+17%), LDL (+9%), and HDL (+6%) cholesterol but remained stable for triglycerides (-1%) and total:HDL cholesterol ratio (0%).

CONCLUSIONS

in this pilot study, abacavir/lamivudine plus raltegravir was effective and generally well-tolerated over 48 weeks with modest changes in fasting lipids.

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.

Similar efficacy and tolerability of atazanavir compared with atazanavir/ritonavir, each with abacavir/lamivudine after initial suppression with abacavir/lamivudine plus ritonavir-boosted atazanavir in HIV-infected patients

BACKGROUND

Treatment simplification strategies involving induction with a ritonavir (RTV)-boosted (/r) protease inhibitor regimen followed by simplification (without RTV) are appealing because they may offer sustained virologic suppression while minimizing potential long-term adverse effects associated with RTV.

METHODS

This open-label, randomized, noninferiority study enrolled 515 antiretroviral therapy-naive patients to receive abacavir/lamivudine plus atazanavir/RTV (ATV/r) followed by randomization at week 36 (N = 419) to maintain or discontinue RTV for an additional 48 weeks. Eligibility for randomization required confirmed HIV RNA level below 50 copies/ml and no virologic failure. Protocol-defined virologic failure after week 36 was confirmed rebound of HIV RNA level at least 400 copies/ml. The primary endpoint was the proportion of patients with HIV RNA level below 50 copies/ml at week 84 (time to loss of virologic response). This study is registered with ClinicalTrials.gov number NCT00440947.

RESULTS

At week 84, noninferiority of ATV to ATV/r (95% confidence interval around the treatment difference -1.75 to 12.48%) was demonstrated with 181 of 210 (86%) patients in the ATV group and 169 of 209 (81%) in the ATV/r group maintaining HIV RNA level below 50 copies/ml. During the randomized phase (weeks 36-84), 10 versus 14% of patients in the ATV and ATV/r arms, respectively, experienced a drug-related grades 2-4 adverse event with hyperbilirubinemia being the most frequently reported (4 versus 10%). The overall rate of protocol-defined virologic failure was 2%; no patient had virus that developed a major protease inhibitor mutation.

CONCLUSION

ATV in combination with abacavir/lamivudine is a potent and well tolerated regimen in patients who have achieved initial suppression on an induction regimen and represents a viable treatment simplification strategy.

Effects of nucleoside reverse transcriptase inhibitor backbone on the efficacy of first-line boosted highly active antiretroviral therapy based on protease inhibitors: meta-regression analysis of 12 clinical trials in 5168 patients

OBJECTIVES

Tenofovir/emtricitabine (TDF/FTC) and abacavir/lamivudine (ABC/3TC) are widely used with ritonavir (RTV)-boosted protease inhibitors (PIs) as first-line highly active antiretroviral therapy (HAART), but there is conflicting evidence on their relative efficacy. The ACTG 5202 and BICOMBO trials suggested higher efficacy for TDF/FTC, whereas the HEAT trial showed no efficacy difference between the nucleoside reverse transcriptase inhibitor (NRTI) backbones.

METHODS

A systematic MEDLINE search identified 21 treatment arms in 12 clinical trials of 5168 antiretroviral-naïve patients, where TDF/FTC (n=3399) or ABC/3TC (n=1769) was used with RTV-boosted PI. For each NRTI backbone and RTV-boosted PI, the percentage of patients with viral load <50 HIV-1 RNA copies/mL at week 48 by standardized Intent to Treat, Time to Loss of Virological Failure (ITT TLOVR) analysis were combined using inverse-variance weighting. The effect of baseline HIV RNA, CD4 cell count and choice of NRTI backbone were examined using a weighted analysis of covariance.

RESULTS

Across all the trials, HIV RNA suppression rates were significantly higher for those with baseline viral load below 100,000 copies/mL (77.2%) vs. above 100,000 copies/mL (70.9%) (P=0.0005). For the trials of lopinavir/ritonavir (LPV/r), atazanavir/ritonavir (ATV/r) and fosamprenavir/ritonavir (FAPV/r) using either TDF/FTC or ABC/3TC, the HIV RNA responses were significantly lower when ABC/3TC was used, relative to TDF/FTC, for all patients (P=0.0015) and for patients with baseline viral load <100,000 copies/mL (70.1%vs. 80.6%, P=0.0161), and was borderline for those with viral load >100,000 copies/mL (67.5%vs. 71.5%, P=0.0523).

CONCLUSIONS

This systematic meta-regression analysis suggests higher efficacy for first-line use of a TDF/FTC NRTI backbone with boosted PIs, relative to use of ABC/3TC. However, this effect may be confounded by differences between the trials in terms of baseline characteristics, patient management or adherence.

[AIDS Study Group/Spanish AIDS Plan consensus document on antiretroviral therapy in adults with human immunodeficiency virus infection (updated January 2010)]

OBJECTIVE

This consensus document is an update of antiretroviral therapy recommendations for adult patients with human immunodeficiency virus infection.

METHODS

To formulate these recommendations a panel made up of members of the Grupo de Estudio de Sida (Gesida, AIDS Study Group) and the Plan Nacional sobre el Sida (PNS, Spanish AIDS Plan) reviewed the advances in the current understanding of the pathophysiology of human immunodeficiency virus (HIV) infection, the efficacy and safety of clinical trials, and cohort and pharmacokinetic studies published in biomedical journals or presented at scientific meetings. Three levels of evidence were defined according to the data source: randomized studies (level A), cohort or case-control studies (level B), and expert opinion (level C). The decision to recommend, consider or not to recommend ART was established in each situation.

RESULTS

Currently, the treatment of choice for chronic HIV infection is the combination of three drugs of two different classes, including 2 nucleosides or nucleotide analogs (NRTI) plus 1 non-nucleoside (NNRTI) or 1 boosted protease inhibitor (PI/r), but other combinations are possible. Initiation of ART is recommended in patients with symptomatic HIV infection. In asymptomatic patients, initiation of ART is recommended on the basis of CD4 lymphocyte counts, plasma viral load and patient co-morbidities, as follows: 1) therapy should be started in patients with CD4 counts below 350 cells/microl; 2) When CD4 counts are between 350 and 500 cells/microl, therapy should be started in case of cirrhosis, chronic hepatitis C, high cardiovascular risk, HIV nephropathy, HIV viral load above 100,000 copies/ml, proportion of CD4 cells under 14%, and in people aged over 55; 3) Therapy should be deferred when CD4 are above 500 cells/microl, but could be considered if any of previous considerations concurs. Treatment should be initiated in case of hepatitis B requiring treatment and should be considered for reduce sexual transmission. The objective of ART is to achieve an undetectable viral load. Adherence to therapy plays an essential role in maintaining antiviral response. Therapeutic options are limited after ART failures but undetectable viral loads maybe possible with the new drugs even in highly drug experienced patients. Genotype studies are useful in these situations. Drug toxicity of ART therapy is losing importance as benefits exceed adverse effects. Criteria for antiretroviral treatment in acute infection, pregnancy and post-exposure prophylaxis are mentioned as well as the management of HIV co-infection with hepatitis B or C.

CONCLUSIONS

CD4 cells counts, viral load and patient co-morbidities are the most important reference factors to consider when initiating ART in asymptomatic patients. The large number of available drugs, the increased sensitivity of tests to monitor viral load, and the ability to determine viral resistance is leading to a more individualized therapy approach in order to achieve undetectable viral load under any circumstances.

Impact of low abundance HIV variants on response to ritonavir-boosted atazanavir or fosamprenavir given once daily with tenofovir/emtricitabine in antiretroviral-naive HIV-infected patients

Population genotyping (PG) can underestimate resistance if resistance-containing low abundance variants go undetected. PG and clonal analysis (CA) results were compared in virologic failures (VFs) from a 48-week clinical trial that evaluated once-daily fosamprenavir/ritonavir (FPV/r) 1400 mg/100 mg or atazanavir/ritonavir (ATV/r) 300 mg/100 mg, each combined with tenofovir/emtricitabine, in antiretroviral-naive patients. VF was defined as confirmed HIV-1 RNA > or =400 copies/ml at > or =24 weeks or viral rebound >400 copies/ml any time following viral suppression. All patients had baseline PG. One hundred and six patients enrolled (53/arm). Baseline resistance mutations were more prevalent in patients receiving FPV/r (10/53) than ATV/r (3/53). Seven patients (7%) were VFs-four on FPV/r and three on ATV/r. In the four FPV/r-treated VFs, baseline HIV TAMs combinations and/or PI mutations were detected in one by PG at VF (RT: L210W + T215C; PR: M46I + L76V) and three others by CA alone (RT: L210W + T215Y; RT: M41L; RT: K65R + K70R; PR: I47V); all four had study drug-associated mutations (CA detecting more HIV-1 resistance mutations than PG). In the three ATV/r VFs, no baseline drug-associated mutations were detected by PG; for one patient CA detected RT: K65R; PR: I84V. Phylogenetic analysis revealed tight clustering for FPV/r-treated VFs with highly related clones, whereas HIV-1 from ATV/r-treated VFs had no outgrowth from baseline of low abundance resistance-containing variants. In conclusion, low-abundance HIV resistance-containing variants were detected in baseline samples from patients with VF. The archived viruses that reemerged under selection pressure and acquired additional mutations were found primarily in patients in the FPV/r arm. Despite this and a baseline resistance imbalance between the two arms, FPV/r and ATV/r provided similar virologic suppression through 48 weeks; however, these findings highlight the necessity for the development of quick and inexpensive methods for detection of minority species to better guide therapy selection.

Safety and efficacy of a 36-week induction regimen of abacavir/lamivudine and ritonavir-boosted atazanavir in HIV-infected patients

PURPOSE

The ARIES study assessed safety and efficacy of an induction regimen with atazanavir/ritonavir (ATV/RTV) + abacavir/lamivudine (ABC/3TC) followed by simplification to ATV + ABC/3TC in antiretroviral-naïve patients.

METHODS

This report includes a noncomparative analysis of all patients in the induction phase of the ARIES study through 36 weeks (clinicaltrials.gov: NCT00440947). This open-label study included 515 antiretroviral-naïve,HLA-B*5701-negative patients receiving a regimen of ATV 300 mg, RTV 100 mg, and ABC/3TC 600 mg/300 mg once daily for 36 weeks; eligible patients were then randomized to continue the induction regimen or simplify to ATV 400 mg plus ABC/3TC 600 mg/300 mg once daily.

RESULTS

Eighty-six percent (442/515) of patients completed 36 weeks on study; 80% (410/515) achieved HIV RNA <50 copies/mL (84% and 76% of patients with baseline HIV RNA of < and >or=100,000 copies/mL achieved this endpoint). Virologic failure (VF) was uncommon (3%); treatment-emergent major protease inhibitor and nucleoside reverse transcriptase inhibitor mutations were detected in 0/15 and 4/15 patients, respectively. Median CD4+ cell increase was 171 (range, -176 to 718) cells/mm(3). Hyperbilirubinemia (13%), diarrhea (4%), nausea (2%), and rash (2%) were the most frequent drug-related Grade 2-4 adverse events. Few adverse events (3%) led to study discontinuation.

CONCLUSIONS

Induction with ATV/RTV + ABC/3TC once daily provides an efficacious and well-tolerated regimen for the initial treatment of HIV.

Abacavir/lamivudine fixed dose combination in the treatment of patients with HIV infection

HIV infection remains a common cause of morbidity and mortality worldwide. Fortunately, patients treated with combination antiretroviral therapy (ART) have significantly improved survival rates and quality of life. The standard of care for the treatment of ART-naive patients includes three drugs, two of which should be nucleoside reverse transcriptase inhibitors (NRTIs). Abacavir/lamivudine (ABC/3TC) is a fixed dose combination NRTI tablet that has been approved as an NRTI backbone. ABC/3TC is among the NRTI combinations that are recommended as first line in the most recent International AIDS Society–USA guidelines and WHO European Region protocol. However, owing to recently published data raising the possibility of an association between abacavir and heart disease, as well as data regarding efficacy in patients with higher HIV RNA levels, ABC/3TC has now been listed as an alternative NRTI backbone in the latest USA Department of Health and Human Services guidelines. While ABC has been associated with a hypersensitivity reaction that may be severe, a new test has been demonstrated to be effective in screening for the gene that is associated with this reaction.

Cardiovascular complications in HIV management: past, present, and future

Highly active antiretroviral therapy (HAART) has significantly improved the prognosis for many individuals with HIV infection. Consequently, HIV infection has become a chronic and manageable disease. The focus on long-term management of patients with HIV infection has broadened to include comorbid conditions, most notably cardiovascular disease. Patients with HIV infection share many cardiovascular risk factors with the general population, and HIV infection itself may increase cardiovascular risk. Changes in lipid profiles associated with increased cardiovascular risk that have been observed with some HAART regimens have been a cause for concern among clinicians who treat HIV-infected patients. However, the lipid effects of HAART seem to depend on the type and duration of regimens employed. They can be managed effectively according to current guidelines that recommend lifestyle changes (eg, improved diet, increased exercise, smoking cessation) and pharmacologic therapy described in established treatment paradigms for patients on antiretroviral therapy and similar to measures currently used by the general population. A review of the clinical data indicates that the virologic and immunologic benefits of HAART clearly outweigh any metabolic effects observed in some patients over time and that preexisting, established cardiovascular risk factors contribute significantly to the potential development of cardiovascular events. These benefits of antiretroviral therapy have been demonstrated in studies comparing the superior efficacy of continuous vs. intermittent HAART.

[Efficacy of atazanavir in treatment-naive patients]

The characteristics of atazanavir (convenient doses, good tolerance, and excellent lipid profile) makes it an attractive drug to be included in initial regimes. Clinical trials have been performed on patients with no previous antiretroviral treatment, either atazanavir without boost (400 mg once per day) or atazanavir boosted with ritonavir (400/100 mg). Although atazanavir without boost is effective, there is a tendency for a higher number of failures and a higher development of resistant mutations than in patients who fail with boosted atazanavir. Therefore, it is recommended to use boosted atazanavir in patients that start on treatment. In clinical studies, boosted atazanavir can be used with any nucleoside analogue. No pharmacokinetic or pharmacodynamic interaction problems have been detected with the two nucleoside combinations at fixed doses (tenofovir/FTC, abacavir/3TC). Randomised clinical studies have been carried out that compared atazanavir with other boosted protease inhibitors. In the comparative study with lopinavir/ritonavir administered two times a day, atazanavir/ritonavir once per day demonstrated noninferiority, with a similar efficacy regardless of the patient baseline viral load. The atazanavir/ritonavir virological efficacy did not appear to be affected by the baseline immunological status of the patients, which did influence the lopinavir/ritonavir response. Atazanavir/ritonavir is a useful drug combination in the initial treatment of HIV infected adult patients. Its increased virological and immunological efficacy, together with its ease of administration, good tolerance and excellent lipid profile makes it a PI of choice in these patients.

[Lipid profile of atazanavir]

It is currently known that exposure to antiretroviral treatment, particularly to the classic protease inhibitors, is associated with an increased risk of suffering from cardiovascular disease, although stopping antiretroviral treatment can cause an even greater risk. Recommendations have been made on how to deal with dyslipaemia and cardiovascular risk in seropositive patients. These recommendations are similar to those for the general population, but include the particular feature of considering including benign treatment with lipids wherever possible. Atazanavir has different characteristics from other protease inhibitors as regards its effects on adipose tissue and metabolism in general. Atazanavir is not associated with increases in total cholesterol, LDL-cholesterol or triglycerides as with other PI in initial, rescue or simplification therapy. The results of in vitro studies and clinical studies are clear and convincing. These characteristics give it a particular role that is very attractive when deciding the most suitable antiretroviral treatment for a proportion of HIV-infected patients in whom the reduction in cardiovascular risk is seen as a priority.

[Clinical utility of atazanavir]

Atazanavir (ATV) is a protease inhibitor (PI) in which its main qualities, compared to other PI are dosing convenience, good tolerability and excellent metabolic profile. These characteristics makes it more like a nonnucleoside than a PI, but with the increased genetic barrier common to PI. It is indicated in initial treatment, simplification treatment or a change due to toxicity and in first line rescue treatment. The administering of ATV boosted with ritonavir (300/100 mg/d) has been approved in Europe in all clinical situations. In naïve patients it has been combined with practically all the nucleoside analogue pairs and has shown to be as effective as lopinavir/ritonavir and even efavirenz. In the USA, this indication has been approved for almost 5 years and ATV has become the most prescribed PI, while the EMEA has approved it this year. ATV is an optimal drug to replace other antiretrovirals in simplification strategies or changes due to toxicity. In several studies it has been shown that, in patients with good virological control, it can LPV/r or another PI, the therapeutic efficacy being maintained, with excellent tolerance and an improved lipid profile, and decreasing the cardiovascular risk. This strategy is widely used in Spain. In this scenario some patients could benefit from non-boosted ATV treatment (400 mg/d). ATV is an effective and very attractive option in first line rescue treatments in which the virus shows little or no resistance to PI, as its simplicity and tolerability can improve problems with compliance, the main cause of therapeutic failure. In patients with moderate resistance to PI, ATV is as effective as LPV/r. The survival of patients with HIV infection is increasingly longer and factors such as tolerability, cardiovascular risk and the adaptability of the treatment to the lifestyle of the patient, become more important, therefore ATV must play an important role in the treatment of HIV-infection.