Triple nucleoside treatment with abacavir plus the lamivudine/zidovudine combination tablet (COM) compared to indinavir/COM in antiretroviral therapy-naïve adults: results of a 48-week open-label, equivalence trial (CNA3014)

Effect of Vitamin D Supplementation on CD4 Count in HIV-Infected Children and Adolescents in North India: A Non-Randomized Comparative Study

BACKGROUND

HIV infection is still a serious public health issue globally. Suboptimal vitamin D status is highly prevalent in HIV-infected children and adolescents throughout the world.

OBJECTIVES

To evaluate the outcome of vitamin D supplementation on CD4 count in HIV-infected children and adolescents with suboptimal vitamin D status.

METHODS

Vitamin D level of HIV-infected children and adolescents were measured at enrolment. Suboptimal vitamin D level was defined as 25(OH)D < 30 ng/ml. Vitamin D insufficiency and deficiency were defined as 21-29 and <20 ng/ml, respectively. Children with suboptimal vitamin D levels were supplemented with vitamin D.

RESULTS

This was a single-centre, non-randomized comparative study enrolling 50 eligible participants. There were 20 patients who were vitamin D sufficient, 7 were vitamin D insufficient and 23 were found to be vitamin D deficient at enrolment. However, after supplementation, the status of sufficient remained same and 7 insufficient become sufficient, whereas in 23 deficient, 18 (78.3%) become sufficient and 5 (21.7%) become insufficient and this change was found statistically significant among the groups (χ2 = 6.52, p = 0.038). There was a significant improvement of CD4 count from baseline to 4 months in deficient group on vitamin D supplementation (p value < 0.001; 1.2-fold rise). No significant change was seen in vitamin D insufficient (p value = 0.791) and sufficient groups (p value = 0.168).

CONCLUSION

Vitamin D should be supplemented in HIV-infected children on ART with low CD4 counts.

Comparative efficacy and safety of first-line antiretroviral therapy for the treatment of HIV infection: a systematic review and network meta-analysis

BACKGROUND

New antiretroviral therapy (ART) regimens for HIV could improve clinical outcomes for patients. To inform global guidelines, we aimed to assess the comparative effectiveness of recommended ART regimens for HIV in ART-naive patients.

METHODS

For this systematic review and network meta-analysis, we searched for randomised clinical trials published up to July 5, 2015, comparing recommended antiretroviral regimens in treatment-naive adults and adolescents (aged 12 years or older) with HIV. We extracted data on trial and patient characteristics, and the following primary outcomes: viral suppression, mortality, AIDS defining illnesses, discontinuations, discontinuations due to adverse events, and serious adverse events. We synthesised data using network meta-analyses in a Bayesian framework and included older treatments, such as indinavir, to serve as connecting nodes. We defined network nodes in terms of specific antivirals rather than specific ART regimens. We categorised backbone regimens and adjusted for them through group-specific meta-regression. We used the GRADE framework to interpret the strength of inference.

FINDINGS

We identified 5865 citations through database searches and other sources, of which, 126 articles related to 71 unique trials were included in the network analysis, including 34 032 patients randomly assigned to 161 treatment groups. For viral suppression at 48 weeks, compared with efavirenz, the odds ratio (OR) for viral suppression was 1·87 (95% credible interval [CrI] 1·34-2·64) with dolutegravir and 1·40 (1·02-1·96) with raltegravir; with respect to viral suppression, low-dose efavirenz was similar to all other treatments. Both low-dose efavirenz and integrase strand transfer inhibitors tended to be protective of discontinuations due to adverse events relative to normal-dose efavirenz. The most protective effect relative to efavirenz in network meta-analyses was that of dolutegravir (OR 0·26, 95% CrI 0·14-0·47), followed by low-dose efavirenz (0·39, 0·16-0·92). Owing to insufficient data, we could make no conclusions about serious adverse events. Low event rates also limited the quality of evidence with regard to mortality and AIDS defining illnesses.

INTERPRETATION

The efficacy and safety of ART has substantially improved with the introduction of newer drug classes of antiretrovirals that are now available to patients and HIV care providers. Their improved tolerance could be part of a larger solution to improve retention, which is a challenge, particularly in low-income and middle-income country settings.

FUNDING

The World Health Organization.

Higher Virological Effectiveness of NNRTI-Based Antiretroviral Regimens Containing Nevirapine or Efavirenz Compared to a Triple NRTI Regimen As Initial Therapy in HIV-1-Infected Adults

PURPOSE

To compare outcomes of nonnucleoside reverse transcriptase inhibitors (NNRTIs) nevirapine or efavirenz versus abacavir-based regimens with a backbone of zidovudine and lamivudine as initial therapy of treatment-naive adults with HIV-1 infection in routine clinical care.

METHOD

All patients starting their first antiretroviral therapy with any of the studied regimens from January 1999 to December 2002 were included in the analysis. Rates of viral suppression (HIV-RNA below 50 copies/mL) and discontinuation of any component of the regimen were compared at 48 weeks.

RESULTS

Fifty-one patients started with one of the two NNRTI-based regimens and 49 started with the triple nucleoside regimen (3-NRTI). After 48 weeks, more patients in the NNRTI regimens (76.5%) than in the 3-NRTI (51.1%) regimen achieved a HIV-1 RNA level below the limit of detection (<1.7 log10 copies/mL; p = .008). Time to change the antiretroviral regimen was shorter with 3-NRTI (median [range]: 234 [139-329] days) than with NNRTI (346 [0-756] days) (p = .0901). More withdrawals related to drug toxicity or intolerance occurred with the 3-NRTI-based regimen.

CONCLUSION

In a routine clinical care setting, initial antiretroviral treatment with an NNRTI (nevirapine or efavirenz) plus zidovudine and lamivudine was virologically superior and safer than a 3-NRTI therapy (abacavir with the same NRTI backbone).

Virological efficacy of abacavir: systematic review and meta-analysis

OBJECTIVES

The efficacy of abacavir/lamivudine has been reported to be inferior to tenofovir/emtricitabine. Several randomized clinical trials (RCTs) investigated the effectiveness and safety of abacavir/lamivudine and tenofovir/emtricitabine combined antiretroviral treatment (cART) and we have reviewed the available evidence.

DESIGN

Systematic review and meta-analysis of RCTs using standard Cochrane Collaboration methodologies.

METHODS

We calculated risk ratios (RRs) with 95% CIs. The primary outcome was the rate of patients with viral load (VL) below the pre-defined cut-off at 48 weeks and/or at 96 weeks. Where available, results were analysed according to VL screening levels (<100,000 or >100,000 copies/mL) with conventional meta-analytical pooling by subgroups and meta-regression.

RESULTS

Meta-analytical pooling of RCTs with a direct comparison of abacavir/lamivudine and tenofovir/emtricitabine according to baseline VL at 48 weeks (six trials, 4118 patients) showed that the proportions of subjects with VL <50 copies/mL were similar in the overall comparison (RR 0.98; 95% CI 0.94-1.03), in the low baseline VL strata (RR 1.01; 95% CI 0.99-1.03) and in the high baseline VL strata (RR 0.96; 95% CI 0.90-1.03). Meta-regression analysis at 48 weeks confirms the results of subgroup analysis. Similar virological results were found at 96 weeks (four trials, 2003 patients). Differences in the occurrence of adverse events requiring discontinuation of treatment favoured tenofovir recipients (RR 1.26; 95% CI 0.99-1.61), but this difference, mostly related to suspected abacavir hypersensitivity reaction, was not statistically significant.

CONCLUSIONS

Our cumulative, cross-sectional data suggest a similar virological efficacy of abacavir/lamivudine and tenofovir/emtricitabine regardless of the baseline VL.

A systematic review of a single-class maintenance strategy with nucleoside/nucleotide reverse transcriptase inhibitors in HIV/AIDS

BACKGROUND

Single-drug class regimens with nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs) are generally not recommended as initial therapy because they are inferior compared with therapy with two NRTIs plus efavirenz. However, triple-NRTI combinations can be useful in specific circumstances such as in tuberculosis coinfection, pregnancy or dyslipidaemia. Here, we review the potential of such combinations to maintain viral suppression after induction of suppression by standard combination antiretroviral therapy (cART) and to evaluate the trade-off of NRTI-only regimens for metabolic control.

METHODS

We conducted a systematic search of the literature in two databases from 1 January 1998 up to 1 March 2013: Medline, through the search engine PubMed, and Embase.

RESULTS

A total of 11 randomized controlled trials (RCTs) with 2,105 patients and 3 observational studies with 2,639 patients were included. Studies including patients with mono- or dual-NRTI treatment before start of effective cART showed a tendency to higher failure rate because of resistance based on archived viral mutations. In studies with ART-naive subjects before start of cART, triple-NRTI combination showed virological activity comparable to two NRTIs plus a protease inhibitor or a non-nucleoside reverse transcriptase inhibitor in all RCTs, but not in one cohort study. Switching improved serum lipids significantly.

CONCLUSIONS

Of the studied triple-NRTI combinations only abacavir/lamivudine/zidovudine was sufficiently potent. Triple-NRTI maintenance after successful induction with two-class cART appeared successful in treatment-naive subjects and remains a useful option in specific circumstances, especially when other drugs are not available or drug interactions are an issue.

Use of nucleoside reverse transcriptase inhibitor-only regimens in HIV-infected children and adolescents

OBJECTIVE

In adults, nucleoside reverse transcriptase inhibitor-only antiretroviral regimens (NOARs) with ≥3 nucleoside reverse transcriptase inhibitors are less potent than highly active antiretroviral therapy (HAART). Published pediatric experience with NOARs is limited; thus, we wished to better define the virological, immunological and toxicological effects of NOARs in children and adolescents.

METHODS

We analyzed data from NOAR-treated participants in LEGACY, a multicenter observational cohort study of HIV-infected children and adolescents. NOAR-treated case-participants were matched to participants without prior NOAR who initiated HAART during the same year for comparison.

RESULTS

Of 575 participants with data from time of HIV diagnosis through 2006, 67 (12%) received NOARs for at least 24 weeks; most (46%) received the fixed dose combination of zidovudine/lamivudine/abacavir. NOAR use peaked in 2001 to 2002. NOAR-treated participants were significantly older and more treatment experienced than HAART-treated participants. Virologic outcomes, including the percentage of participants with a plasma HIV RNA viral load <400 copies/mL at week 24 (47% versus 34%) and the mean 24-week change in log10 plasma HIV RNA viral load from baseline (-0.63 versus -1.02), were similar between NOAR- and HAART-treated participants, but virologic rebound was more likely in NOAR-treated participants (77% versus 54%, P = 0.02). Increase in CD4 percentage points from baseline to 24 weeks was negligible in NOAR-treated participants compared with HAART-treated participants (0.95% versus 10.1%, P < 0.001). Anemia and leukopenia were more commonly reported with NOARs than HAART.

DISCUSSION

Week 24 virologic outcomes were similar between NOAR- and HAART-treated participants, but NOAR durability was poorer and their use was associated with less immunologic reconstitution. NOARs should play a limited role in pediatric and adolescent antiretroviral therapy.

Abacavir-based triple nucleoside regimens for maintenance therapy in patients with HIV

BACKGROUND

Regimen simplification can be defined as a change in established effective therapy to reduce pill burden and dosing frequency, to enhance tolerability, or to decrease specific food and fluid requirements. Many patients on suppressive antiretroviral therapy may be considered candidates for a simplification strategy and, among them, those who have achieved virologic suppression. Several clinical trials have evaluated the efficacy of triple nucleoside combination as a simplification therapy in patients who achieved virologic suppression

OBJECTIVES

The aim of this review is to combine randomised, controlled trials to examine whether in patients with undetectable viraemia on a Protease inhibitor (PI) based regimen simplification treatment with abacavir (ABC)-based triple-nucleoside combinations has similar rates of efficacy and tolerability compared with a PI regimen or simplification with a NNRTIs (efavirenz-EFV- or nevirapine-NVP) containing regimen. Studies were included if they had at least two of the three interventions, including one 3NRTI arm.

SEARCH METHODS

Electronic databases and conference proceedings were searched (1996-2012) with relevant search terms without limits to language.

SELECTION CRITERIA

Randomised controlled trials (RCTs) only are included in this review. Patients population is represented by HIV-infected adult patients treated with a PI-containing regimen (PI or boosted PI),  with undetectable viral load. Patients on a PI-containing regimen had three possibilities: continue the PI regimen or switch to a simplification maintenance regimen, including switch to a NNRTI (EFV or NVP) containing regimen, or switch to a triple-NRTI regimen (ABC-zidovudine-lamivudine)

DATA COLLECTION AND ANALYSIS

The primary outcomes were: proportion of patients discontinuing or switching antiretroviral therapy due to virologic failure or to adverse events; death (all cause) and AIDS defining illness; occurrence of myocardial infarction and cardiovascular disease. Secondary outcomes  were: proportion of patients maintaining an undetectable viral load (e.g. HIV-RNA <50 or <400 copies/mm(3)); change in mean CD4+ cell count; occurrence of lipodystrophy. We applied Cochrane Collaboration tools to assess each individual study for risk for bias.

MAIN RESULTS

We included eight RCT, for a total of 1,610 patients. All the studies included HIV-1 infected patients virologically suppressed after a successful treatment with PI containing ART. Articles included in the analysis were published between 2001 and 2010, and could be classified as low risk of bias trials in most of the domains considered. Overall, there was no significant difference between the participants on triple nucleoside combination and controls, either PI-based or NNRTI based in terms of overall failures, death and AIDS related events, and rates of patients with viral load below the detectability cut-off. For the outcomes discontinuation for adverse events and virologic failures, the RRs were not significant , albeit  being not far from the alpha level of 0.05, thus suggesting a weak evidence of lower incidence of side effects  and an higher incidence of virologic failure in the 3NRTI group compared to controls . Change in lipids and in CD4 cells from baselines were reported in 7 studies, but inconsistency in reporting these data did not allow quantitative analysis. However, all agreed that simplification with ABC had a favourable and significant impact on lipid metabolism compared to control group. An increase in CD4 cells count from baseline was evident in all analysed studies, without significant differences between ABC and controls in individual studies.

AUTHORS' CONCLUSIONS

The strategy of switching to triple nucleoside regimens shows weak evidence of lower incidence of side effects and a higher incidence of virologic failure in the 3NRTI group compared to controls. Simplification with 3NRTI holds the advantages of preserving other classes of antiretroviral drugs, to lower blood lipids, and to be cost effective and simple to administer.Thus, simplification with triple nucleoside regimens AZT + 3TC + ABC should be still considered for individuals who are unable to tolerate or have contraindications to NNRTI or PI based regimens. Additional data are needed on longer-term efficacy of triple NRTI regimens, particularly on the development of antiretroviral resistance. Though studies in the current review were conducted between 2001 and 2010, the large majority of patients from studies analysed received old PI regimens (e.g., indinavir, ritonavir, nelfinavir, saquinavir) not longer recommended by International Guidelines. Since current guidelines recommend new "lipid -friendly" PI, future studies should compare regimens containing these news PIs to triple NRTI regimens. More realistically, however, there are opportunities to examine these issues in existing cohorts.

Deficient reporting and interpretation of non-inferiority randomized clinical trials in HIV patients: a systematic review

OBJECTIVES

Non-inferiority (NI) randomized clinical trials (RCTs) commonly evaluate efficacy of new antiretroviral (ARV) drugs in human immunodeficiency virus (HIV) patients. Their reporting and interpretation have not been systematically evaluated. We evaluated the reporting of NI RCTs in HIV patients according to the CONSORT statement and assessed the degree of misinterpretation of RCTs when NI was inconclusive or not established.

DESIGN

Systematic review.

METHODS

PubMed, Web of Science, and Scopus were reviewed until December 2011. Selection and extraction was performed independently by three reviewers.

RESULTS

Of the 42 RCTs (n = 21,919; range 41-3,316) selected, 23 were in ARV-naïve and 19 in ARV-experienced patients. Twenty-seven (64%) RCTs provided information about prior RCTs of the active comparator, and 37 (88%) used 2-sided CIs. Two thirds of trials used a NI margin between 10 and 12%, although only 12 explained the method to determine it. Blinding was used in 9 studies only. The main conclusion was based on both intention-to-treat (ITT) and per protocol (PP) analyses in 5 trials, on PP analysis only in 4 studies, and on ITT only in 31 studies. Eleven of 16 studies with NI inconclusive or not established highlighted NI or equivalence, and distracted readers with positive secondary results.

CONCLUSIONS

There is poor reporting and interpretation of NI RCTs performed in HIV patients. Maximizing the reporting of the method of NI margin determination, use of blinding and both ITT and PP analyses, and interpreting negative NI according to actual primary findings will improve the understanding of results and their translation into clinical practice.

Co-formulated abacavir-lamivudine-zidovudine for initial treatment of HIV infection and AIDS

BACKGROUND

UNAIDS estimates that 34 million people are currently living with the human immunodeficiency virus (HIV) worldwide. Currently recommended regimens for initiating HIV treatment consist of either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or ritonavir-boosted protease inhibitor (PI) combined with two nucleoside reverse transcriptase inhibitors (NRTIs). However, there may be some patients for whom NNRTIs and PIs may not be appropriate. This is an update of the review published in the Cochrane Library Issue 3, 2009.

OBJECTIVES

To evaluate the effects of any fixed-dose combination of three NRTIs (co-formulated abacavir-lamivudine-zidovudine) for initial treatment of HIV infection.

SEARCH METHODS

Between December 2010 and July 2011, we used standard Cochrane methods to search electronic databases and conference proceedings with relevant search terms without limits to language or publication status.

SELECTION CRITERIA

We selected randomised controlled trials (RCTs) with a minimum follow-up time of six months which compared co-formulated abacavir-lamivudine-zidovudine with either PI-based or NNRTI-based therapy among antiretroviral-naive HIV-infected patients aged at least 13 years.

DATA COLLECTION AND ANALYSIS

Three authors independently selected eligible studies, assessed risk of bias, and extracted data; resolving discrepancies by consensus. We calculated the risk ratio (RR) or mean difference (MD), as appropriate, with its 95% confidence interval (CI) and conducted meta-analysis using the random-effects method because of significant statistical heterogeneity (P<0.1).

MAIN RESULTS

We identified 15 potentially eligible RCTs, four of which met our inclusion criteria. The four included RCTs were conducted in the United States of America (USA); USA, Puerto Rico, Guatemala, Dominican Republic, and Panama; USA and Mexico; and Botswana, respectively. The RCTs compared co-formulated abacavir-lamivudine-zidovudine to treatment based on efavirenz (NNRTI), nelfinavir (PI), atazanavir (PI), and co-formulated lopinavir-ritonavir (PI), respectively. Overall, there was no significant difference in virological suppression between co-formulated abacavir-lamivudine-zidovudine and NNRTI- or PI-based therapy (4 trials; 2247 participants: RR 0.73, 95% CI 0.39 to 1.36). However, the results showed significant heterogeneity (I(2)=79%); with co-formulated abacavir-lamivudine-zidovudine inferior to NNRTI (1 trial, 1147 participants: RR 0.35, 95%CI 0.26 to 0.49) but with a trend towards co-formulated abacavir-lamivudine-zidovudine being superior to PI (3 trials, 1110 participants: RR 1.07, 95%CI 1.00 to 1.16; I(2)=0%). We found no significant differences between co-formulated abacavir-lamivudine-zidovudine and either PI or NNRTI on CD4+ cell counts (3 trials, 1687 participants: MD -0.01, 95%CI -0.11 to 0.09; I(2)=0%), severe adverse events (4 trials: RR 1.22, 95%CI 0.78 to 1.92; I(2)=62%) and hypersensitivity reactions (4 trials: RR 4.04, 95% CI 0.41 to 40.02; I(2)=72%). Only two studies involving PIs reported data on the lipid profile. One study found that the mean increase in total cholesterol from baseline to 96 weeks was significantly lower with co-formulated abacavir-lamivudine-zidovudine than with nelfinavir, but there were no differences with triglyceride levels. The second study found the fasting lipid profile to be comparable in both co-formulated abacavir-lamivudine-zidovudine and atazanavir arms at 48 weeks.The significant heterogeneity of effects for most outcomes evaluated was largely due to differences in the control therapy used in the included trials (i.e. NNRTIs or PIs). Using the GRADE approach, we rated the overall quality of the evidence on the relative effects of co-formulated abacavir-lamivudine-zidovudine for initial treatment of HIV infection as moderate. The main reason for downgrading the quality of the evidence was imprecision of the findings. The estimate of the treatment effect for each outcome has wide confidence intervals, which extend from the fixed-dose NRTI combination regimen being appreciably better to the regimen being appreciably worse than PI- or NNRTI-based regimens.

AUTHORS' CONCLUSIONS

This review provides evidence that co-formulated abacavir-lamivudine-zidovudine remains a viable option for initiating antiretroviral therapy, especially in HIV-infected patients with pre-existing hyperlipidaemia. The varied geographical locations of the included trials augment the external validity of these findings. We are moderately confident in our estimate of the treatment effects of the triple NRTI regimen as initial therapy for HIV infection. In the context of the GRADE approach, such moderate quality of evidence implies that the true effects of the regimen are likely to be close to the estimate of effects found in this review; but there is a possibility that they could be substantially different.  Further research should be geared towards defining the subgroup of HIV patients for whom this regimen will be most beneficial.

Effectiveness of efavirenz-based regimens in young HIV-infected children treated for tuberculosis: a treatment option for resource-limited settings

BACKGROUND

Antiretroviral treatment (ART) options for young children co-infected with HIV and tuberculosis are limited in resource-poor settings due to limited data on the use of efavirenz (EFV). Using available pharmacokinetic data, an EFV dosing schedule was developed for young co-infected children and implemented as the standard of care at Macha Hospital in Southern Province, Zambia. Treatment outcomes in children younger than 3 years of age or weighing less than 10 kg receiving either EFV-based ART plus anti-tuberculous treatment or nevirapine-based (NVP) ART were compared.

METHODS

Treatment outcomes were measured in a cohort of HIV-infected children seeking care at Macha Hospital in rural Zambia from 2007 to 2010. Information on the diagnosis and treatment of tuberculosis was abstracted from medical records.

RESULTS

Forty-five children treated for tuberculosis initiated an EFV-based regimen and 69 children initiated a NVP-based regimen, 7 of whom also were treated for tuberculosis. Children receiving both regimens were comparable in age, but children receiving EFV started ART with a lower CD4(+) T-cell percentage and weight-for-age z-score. Children receiving EFV experienced increases in both CD4(+) T-cell percentage and weight-for-age z-score during follow-up, such that levels were comparable to children receiving NVP after two years of ART. Cumulative survival after 12 months of ART did not differ between groups (NVP:87%;EFV:80%;p = 0.25). Eleven children experienced virologic failure during follow-up.The adjusted hazard ratio of virologic failure comparing EFV to NVP was 0.25 (95% CI:0.05,1.24) and 0.13 (95% CI:0.03,0.62) using thresholds of 5000 and 400 copies/mL, respectively.Five children receiving EFV were reported to have had convulsions after ART initiation compared to only one child receiving NVP (p = 0.04).

CONCLUSIONS

Despite poorer health at ART initiation, children treated for tuberculosis and receiving EFV-based regimens showed significant improvements comparable to children receiving NVP-based regimens. EFV-based regimens should be considered for young HIV-infected children co-infected with tuberculosis in resource-limited settings.

Abacavir use and cardiovascular disease events: a meta-analysis of published and unpublished data

BACKGROUND

The use of abacavir (ABC) has been associated with an increased risk of cardiovascular disease in some cohort studies. However, no excess risk of myocardial infarction (MI) with ABC therapy has been observed in individual randomized clinical trials (RCTs) and in the aggregated clinical trials database maintained by the manufacturer of ABC.

OBJECTIVE

To combine all the evidence from RCTs by means of meta-analysis to estimate the effect of combined antiretroviral therapy (cART) containing ABC on MI and overall major cardiovascular events (CVEs).

METHODS

Primary outcomes included MI, CVE, adverse events requiring discontinuation of treatment, and overall mortality. We used a conventional Mantel-Haenszel method, with risk ratio and 95% confidence intervals (CIs) or, in the presence of heterogeneity, a random-effect model.

RESULTS

Data were from 28 primary RCTs (9233 participants) comparing ABC-containing cART (4376 participants) to other regimens not containing ABC (4857 controls). MI data were available from 18 trials (31 episodes in 7054 patients) and CVE data from 20 trials (79 episodes in 7899 patients). Compared to the controls, ABC use did not increase significantly the occurrence of MI (risk ratio 0.73, 95% CI 0.39-1.35; P = 0.31), CVE (risk ratio 0.95, 95% CI 0.62-1.44; P = 0.80), overall mortality (risk ratio 1.20, 95% CI 0.63-2.27; P = 0.58), and adverse events requiring discontinuation of treatment (risk ratio 0.82, 95% CI 0.67-1.00; P = 0.05).

CONCLUSION

This meta-analysis of RCTs does not support the hypothesis that ABC-containing cART regimens carry a greater risk of MI or major cardiovascular events relative to comparator cART.

Antiretroviral regimens in pregnancy and breast-feeding in Botswana

BACKGROUND

The most effective highly active antiretroviral therapy (HAART) to prevent mother-to-child transmission of human immunodeficiency virus type 1 (HIV-1) in pregnancy and its efficacy during breast-feeding are unknown.

METHODS

We randomly assigned 560 HIV-1-infected pregnant women (CD4+ count, > or = 200 cells per cubic millimeter) to receive coformulated abacavir, zidovudine, and lamivudine (the nucleoside reverse-transcriptase inhibitor [NRTI] group) or lopinavir-ritonavir plus zidovudine-lamivudine (the protease-inhibitor group) from 26 to 34 weeks' gestation through planned weaning by 6 months post partum. A total of 170 women with CD4+ counts of less than 200 cells per cubic millimeter received nevirapine plus zidovudine-lamivudine (the observational group). Infants received single-dose nevirapine and 4 weeks of zidovudine.

RESULTS

The rate of virologic suppression to less than 400 copies per milliliter was high and did not differ significantly among the three groups at delivery (96% in the NRTI group, 93% in the protease-inhibitor group, and 94% in the observational group) or throughout the breast-feeding period (92% in the NRTI group, 93% in the protease-inhibitor group, and 95% in the observational group). By 6 months of age, 8 of 709 live-born infants (1.1%) were infected (95% confidence interval [CI], 0.5 to 2.2): 6 were infected in utero (4 in the NRTI group, 1 in the protease-inhibitor group, and 1 in the observational group), and 2 were infected during the breast-feeding period (in the NRTI group). Treatment-limiting adverse events occurred in 2% of women in the NRTI group, 2% of women in the protease-inhibitor group, and 11% of women in the observational group.

CONCLUSIONS

All regimens of HAART from pregnancy through 6 months post partum resulted in high rates of virologic suppression, with an overall rate of mother-to-child transmission of 1.1%. (ClinicalTrials.gov number, NCT00270296.)

Abacavir/lamivudine/zidovudine maintenance after standard induction in antiretroviral therapy-naïve patients: FREE randomized trial interim results

Maintenance with a triple nucleoside reverse transcriptase Inhibitor (NRTI) regimen after successful induction with a dual NRTI/protease inhibitor (PI) combination may be advantageous, because of low pill burden, favorable lipids, and less drug interactions. This strategy to become free of PI-related problems without losing viral efficacy has not been formally tested. We performed a randomized, open-label, multicenter, 96-week comparative study in antiretroviral therapy (ART)-naïve patients with CD4 <or=350 cells/mm(3) and HIV-1 RNA concentrations (viral load [VL]) greater than 30,000 copies per milliliter. Patients were randomized after reaching VL less than 50 copies per milliliter on two consecutive occasions between 12 and 24 weeks after start of zidovudine/lamuvidine and lopinavir/ritonavir combination. Eligible subjects switched to abacavir/lamivudine/zidovudine (TZV) or continued the PI-containing regimen. Here we present the 48-week data with virologic success rate (failure: VL > 50 copies per milliliter). Two hundred seven patients had similar baseline (BL) characteristics: median CD4 180 cells/mm(3), median VL 5.19 log(10) copies per milliliter. One hundred twenty subjects (58%) met randomization criteria. Baseline VL differed significantly between dropouts and randomized subjects (median 5.41 versus 5.06 log(10) copies per milliliter, p = 0.017), as did CD4 cells (median 160 and 200 cells/mm(3), p = 0.044). Sixty-one subjects received TZV and 59 subjects continued NRTIs/PI. At week 48, 2 patients in the TZV group and 5 in the PI group did not have a sustained virologic suppression (log rank test; p = 0.379). CD4 counts increased significantly in both arms. In ART-naïve patients, TZV maintenance had similar antiviral efficacy compared to continued standard ART at 48 weeks after baseline. Patients on successful standard ART can be safely switched to a NRTI-only regimen, at least for the tested time period.

A combination drug of abacavir-lamivudine-zidovudine (Trizivir) for treating HIV infection and AIDS

BACKGROUND

The human immunodeficiency virus (HIV) has become one of the greatest challenges to global public health. In 2007 UNAIDS estimated that 33.2 million people were living with HIV. Currently recommended regimens for initiating HIV treatment consist of either a non-nucleoside reverse transcriptase inhibitor (NNRTI) or ritonvair-boosted protease inhibitor (PI) combined with two nucleoside reverse transcriptase inhibitors (NRTIs); however, there may be some patients for whom NNRTIs and PIs may not be appropriate.

OBJECTIVES

The aim of this review was to evaluate the effects of Trizivir, a fixed-dose combination of three NRTIs (abacavir-lamivudine-zidovudine) for initial treatment of HIV infection.

SEARCH STRATEGY

In February 2008, we searched the Cochrane Library, PubMed, EMBASE, AIDSearch and GATEWAY and checked reference lists of identified articles. In May 2009, we repeated the search in PubMed and the Cochrane Library.

SELECTION CRITERIA

We selected randomized controlled trials (RCTs) with a minimum follow-up time of six months which compared Trizivir with either a PI- or NNRTI-based therapy among antiretroviral-naive HIV-infected patients aged at least 13 years.

DATA COLLECTION AND ANALYSIS

Three authors independently extracted data. We calculated the relative risk (RR) or mean difference (as appropriate) for each outcome with its 95% confidence interval (CI) and conducted meta-analysis using the random-effects method because of significant statistical heterogeneity (P<0.1).

MAIN RESULTS

We identified nine potentially eligible RCTs, three of which met our inclusion criteria. One trial compared Trizivir to efavirenz (an NNRTI) plus two or three NRTIs; the second trial compared Trizivir to a treatment based on the PI nelfinavir; and the third compared Trizivir to atazanavir (a PI) plus two NRTIs. Overall, there was no significant difference in the incidence of virological failure between participants on Trizivir and those on PI-based or NNRTI-based therapy (three trials, N=1687; RR 1.14, 95% CI 0.56 to 2.32). However, there was significant heterogeneity between the results of the three trials (heterogeneity P=0.009, I(2)=79%), with a significant increase in virological failure for Trizivir compared to efavirenz (N=1147; RR 1.93, 95% CI 1.46 to 2.55) but no difference between Trizivir and PIs (two trials, N=540; RR 0.82, 95% CI 0.50 to 1.36). We found no significant differences between Trizivir and either the PI or NNRTI on CD4+ cell counts (standardized mean difference -0.01, 95% CI -0.11 to 0.09, heterogeneity P=0.59, I(2)=0%), severe adverse events (RR 1.41, 95% CI 0.61 to 3.25, heterogeneity P=0.03, I(2)=73%) and hypersensitivity reactions (RR 4.04, 95% CI 0.41 to 40.02, heterogeneity P=0.03, I(2)=72%). Only the studies involving PIs reported the effect of the treatment regimens on the lipid profile. One study found that at 96 weeks, the mean increase in total cholesterol from baseline was significantly lower with Trizivir than with nelfinavir, but there were no significant differences with triglyceride levels. The second study found the fasting lipid profile to be comparable in both the Trizivir and atazanavir arms at 48 weeks.

AUTHORS' CONCLUSIONS

Our findings indicate that Trizivir remains a viable option for initiating antiretroviral therapy, especially in HIV-infected patients with pre-existing hyperlipidaemia and those who do not tolerate ritonavir.

A randomized, controlled trial of initial anti-retroviral therapy with abacavir/lamivudine/zidovudine twice-daily compared to atazanavir once-daily with lamivudine/zidovudine twice-daily in HIV-infected patients over 48 weeks (ESS100327, the ACTION Study)

Background

Traditional first line regimens containing a non-nucleoside reverse transcriptase inhibitor or protease inhibitor may not be suitable for a subset of antiretroviral-naïve patients such as those with certain co-morbidities, women of child-bearing potential, and intolerability to components of standard first line therapy. This study was conducted to determine if alternate treatment options may meet the needs of both general and special patient populations. The ACTION study was a randomized, open-label, multicenter, 48-week trial that compared the safety and efficacy of a triple nucleoside regimen versus a protease inhibitor plus a dual nucleoside regimen in HIV-1 treatment-naïve subjects.

Results

279 HIV-infected subjects with HIV-1 RNA (VL) >5000 but < 200,000 copies/mL (c/mL) and CD4+ count ≥ 100 cells/mm³ were randomized (1:1) to receive abacavir sulfate/lamivudine/zidovudine (ABC/3TC/ZDV) twice-daily or atazanavir (ATV) once-daily plus lamivudine/zidovudine (3TC/ZDV) twice-daily. Protocol-defined virologic failure was based on multiple failure criteria.

Non-inferiority of ABC/3TC/ZDV to ATV+3TC/ZDV was established with 62% vs. 59% of subjects achieving a VL < 50 c/mL at week 48, [ITT(E), M/S = F, 95% CI: -5.9, 10.4]. Similar results were observed in the 230 (82%) subjects with baseline VL<100,000 c/mL (ABC/3TC/ZDV vs. ATV+3TC/ZDV), 66% vs. 59%; 95% CI: -5.6, 19.5. However, ABC/3TC/ZDV did not meet the non-inferiority criterion compared to ATV+3TC/ZDV in the 48 subjects with baseline VL ≥ 100,000 c/mL, 39% vs. 60%; 95% CI: -49.2, 7.4, respectively. Protocol-defined virologic failure was similar between groups.

Conclusion

ABC/3TC/ZDV demonstrated comparable virologic efficacy to ATV+3TC/ZDV in this population over 48 weeks. In those with a baseline VL ≥ 100,000 c/mL, subjects in the ATV+3TC/ZDV showed better virologic efficacy. Both regimens offer benefits in select therapy-naïve subjects.

Trial Registration

[Clinical Trials Identifier, NCT00082394].

InforMatrix nucleoside/nucleotide reverse transcriptase inhibitor 'backbones'

InforMatrix is an interactive decision matrix technique. This paper describes the use of InforMatrix to determine an order of merit within the various nucleoside and nucleotide reverse transcriptase inhibitors. In the order of merit, six criteria (effectiveness, safety, tolerance, convenience, usability and costs) are weighted against each other. Data necessary for this weighting process are derived from literature as well as personal practical experience. This article gives an overview of the most relevant information from clinical trials, cohort studies and databases concerning backbones consisting of two nucleoside/nucleotide reverse transcriptase inhibitors in the treatment of HIV infections, as well as a description of the interactive decision matrix technique. By using this interactive matrix technique, a rational consideration of the treatment options for backbones consisting of two nucleoside/nucleotide reverse transcriptase inhibitors becomes possible.

Predictors of optimal viral suppression in patients switched to abacavir, lamivudine, and zidovudine: the Swiss HIV Cohort Study

OBJECTIVE

To investigate predictors of continued HIV RNA viral load suppression in individuals switched to abacavir (ABC), lamivudine (3TC) and zidovudine (ZDV) after successful previous treatment with a protease inhibitor or non-nucleoside reverse transcriptase inhibitor-based combination antiretroviral therapy.

DESIGN AND METHODS

An observational cohort study, which included individuals in the Swiss HIV Cohort Study switching to ABC/3TC/ZDV following successful suppression of viral load. The primary endpoint was time to treatment failure defined as the first of the following events: two consecutiveviral load measurements > 400 copies/ml under ABC/3TC/ZDV, one viral load measurement > 400 copies/ml and subsequent discontinuation of ABC/3TC/ZDV within 3 months, AIDS or death.

RESULTS

We included 495 individuals; 47 experienced treatment failure in 1459 person-years of follow-up [rate = 3.22 events/100 person-years; 95% confidence interval (95% CI), 2.30-4.14]. Of all failures, 62% occurred in the first year after switching to ABC/3TC/ZDV. In a Cox regression analysis, treatment failure was independently associated with earlier exposure to nucleoside reverse transcriptase inhibitor (NRTI) mono or dual therapy [hazard ratio (HR), 8.02; 95% CI, 4.19-15.35) and low CD4 cell count at the time of the switch (HR, 0.66; 95% CI, 0.51-0.87 by +100 cells/microl up to 500 cells/microl). In patients without earlier exposure to mono or dual therapy, AIDS prior to switch to simplified maintenance therapy was an additional risk factor.

CONCLUSIONS

The failure rate was low in patients with suppressed viral load and switch to ABC/3TC/ZDV treatment. Patients with earlier exposure to mono or dual NRTI therapy, low CD4 cell count at time of switch, or AIDS are at increased risk of treatment failure, limiting the use of ABC/3TC/ZDV in these patient groups.

Quadruple Nucleoside Therapy with Zidovudine, Lamivudine, Abacavir and Tenofovir in the Treatment of HIV

Highly active antiretroviral therapy (HAART) has significantly reduced morbidity and mortality in HIV-infected patients. However, problems such as short-term or long-term toxicity and the development of drug resistance could necessitate a change in the therapy regimen. Whereas various HAART options with low pill burden and favourable long-term tolerability profiles are available for naive patients, treatment of experienced patients tends to be more complex and remains a challenge. Treatment with class sparing nucleoside-only regimens could be an option in this context, but the combination of zidovudine (AZT), lamivudine (3TC) and abacavir (ABC) has shown to be inferior in terms of virological efficacy compared with the standard regimen. More promising data were obtained when AZT, 3TC and ABC were intensified with tenofovir (TDF), resulting in a quadruple nucleoside therapy. This regimen has demonstrated comparable potency to a standard regimen with AZT, 3TC and efavirenz in treatment-naive patients. Additionally, it has shown to be an efficient treatment option especially in moderately pretreated patients. This is accredited to the potency of the single components and the antagonistic selection pressure of AZT and TDF. The presence of L210W, or at least two of the mutations 41L, 67N, 70R, 215F/Y or 219Q/E, at or before baseline seems to be a predictor of non-response, whereas the presence of M184V does not impede virological response and might even be advantageous. This review summarizes current data on the combined use of AZT, 3TC, ABC and TDF in regard to virological and immunological outcome as well as genotypic predictors of response.

Antiretroviral management of treatment-naive patients

Antiretroviral management of treatment-naive patients begins with the decision of when to start treatment. Current treatment guidelines suggest starting therapy in anyone with AIDS, HIV-related symptoms, or a CD4 cell count less than 200/mm3 regardless of symptoms. Starting treatment in asymptomatic patients with CD4 of more than 200 requires consideration of a number of pros and cons, and individualization is the key. Recommended first-line antiretroviral regimens consist of two nucleoside reverse transcriptase inhibitors together with either a nonnucleoside reverse transcriptase inhibitor or a protease inhibitor (with or without ritonavir boosting). The goal of antiretroviral therapy is maximally to suppress viremia, enhance or improve immune function, and prevent clinical progression.

Intensification of a triple-nucleoside regimen with tenofovir or efavirenz in HIV-1-infected patients with virological suppression

OBJECTIVE

To compare a quadruple-nucleoside with an efavirenz-containing regimen for treatment of HIV-1 infection.

DESIGN

A randomized, open-label study of the AIDS Clinical Trials Group (ACTG).

METHODS

Subjects receiving zidovudine/lamivudine/abacavir on ACTG 5095 with HIV-1 RNA less than 200 copies/ml were randomly assigned to intensify either with tenofovir or efavirenz. Subjects were followed for time to treatment failure, defined as either virological failure or treatment discontinuation. Analyses were intent-to-treat.

RESULTS

One hundred and seventy subjects (21% women; 56% non-white) entered the study. At baseline, 95 and 73% had HIV-1-RNA levels less than 200 and 50 copies/ml, respectively; the median CD4 cell count was 453 cells/microl. Over a median 79 weeks follow-up, 165 (97%) completed the study, three (2%) discontinued, and two (1%) died. Treatment failure occurred in 31 subjects: 18 (21%) (quadruple nucleosides) and 13 (15%) (efavirenz-containing regimen); however the failure-time curves crossed and demonstrated a non-constant treatment effect over time, characterized by more early treatment failures on the efavirenz-containing regimen and more late treatment failures on the four-nucleoside regimen. HIV-1 RNA remained suppressed in more than 88% of subjects to less than 200 copies/ml and in more than 78% to less than 50 copies/ml at weeks 24, 48, and 72, without differences by treatment arm. There were no significant differences between the regimens in CD4 cell increases, time to new grade 3/4 adverse events, or adherence.

CONCLUSION

The safety, tolerability, and efficacy of the four-nucleoside regimen were not significantly different from the efavirenz-containing regimen. These pilot data support further investigation of the quadruple-nucleoside regimen.

Abacavir sulfate/lamivudine/zidovudine fixed combination in the treatment of HIV infection

Treatment of HIV infection has typically been carried out using two nucleoside analogs and a protease inhibitor. Such regimens can be complex and have high pill burdens. Use of alternative regimens, such as triple nucleoside-based regimens, can improve adherence and decrease toxicities associated with protease inhibitor therapy. A formulation of abacavir sulfate/lamivudine/zidovudine allows a dosing schedule of one pill twice daily. The components have performed favorably compared with protease inhibitor-based regimens, such as indinavir. Compared with efavirenz-based regimens, abacavir sulfate/lamivudine/zidovudine has not performed as well. The combination is being studied as a cornerstone for induction maintenance strategies, in which switching a patient to abacavir sulfate/lamivudine/zidovudine has been associated with similar virologic outcomes as continuing with either protease inhibitor- or efavirenz-based regimens. Administration of abacavir sulfate/lamivudine/zidovudine also avoids side effects of antiretroviral therapy, such as hyperlipidemia, but its use is associated with a hypersensitivity reaction in a small number of patients. The combination of abacavir sulfate/lamivudine/zidovudine is an important part of the HIV armamentarium. Its potency and ease of administration make it worth consideration in the treatment of HIV, either by itself or in combination with other agents.

Evolution of Resistance Mutations during Low-Level Viral Replication in HIV-1–Infected Patients Treated with Zidovudine/Lamivudine/Abacavir as a First-Line Regimen

Objective

Long-term evaluation of viral evolution in patients who continued first-line therapy with zidovudine/lamivudine/abacavir (Trizivir [TZV]) in the presence of low-level viral replication and assessment of the impact of mutational patterns selected under TZV on viral load (VL), CD4+ T-cell count (CD4) and subsequent therapeutic options.

Design

Analysis of viral evolution based on genotypic resistance tests (GRT) from samples collected during non-suppressive first-line therapy with TZV.

Methods

Patients from the Frankfurt HIV cohort with at least 3 months uninterrupted first-line therapy with TZV in whom VL and CD4 measurements were performed at baseline and at follow up were identified. Criteria for virological failure (VF) were two consecutive VL >400 copies/ml. GRTs were required at baseline, VF and last visit (LV).

Results

Initially, 23/119 patients were classified as VF; 4/23 were lost to follow up. Median time to VF was 48 weeks. Because of the observed virological and immunological benefit, patients continued TZV for a median of 87 weeks despite detectable viraemia. Median CD4 increase and VL reduction at LV were 120 cells/mm3 and 317,100 copies/ml, respectively, compared to baseline. After 54 weeks of treatment with detectable VL, three mutational patterns were observed: Group A ( n=4) characterized by M184V without further regimen-associated mutations, group B ( n=9) by M184V accompanied by one to three thymidine analogue mutations (TAMs), and group C ( n=6) by M184V and four to six TAMs. No virological or CD4 parameters correlated with these patterns. Group A remained unchanged, thus preserving activity of most nucleoside analogues (NA). However, in the majority of patients (groups B and C) accumulation of mutations at different rates was observed, leading to a sequential loss of NA options.

Conclusions

Continuous treatment with TZV in the presence of viral replication is associated with a stepwise accumulation of resistance mutations. M184V was present in all cases, not followed by further selection of TAMs in a small, unpredictable subgroup of patients. However, in the majority of patients selection of M184V was associated with accumulation of TAMs at different rates leading to a substantial loss of active NAs, despite continuous virological and immunological benefit when compared with baseline.

Pharmacokinetics and safety of indinavir in human immunodeficiency virus-infected pregnant women

Human immunodeficiency virus-infected women (n=16) received indinavir (800 mg three times a day) plus zidovudine plus lamivudine from 14 to 28 weeks of gestation to 12 weeks postpartum. Two women and eight infants experienced grade 3 or 4 toxicities that were possibly treatment related. Indinavir area under the plasma concentration-time curve was 68% lower antepartum versus postpartum, suggesting increased intestinal and/or hepatic CYP3A activity during pregnancy.

Evolving simplified treatment strategies for HIV infection: the role of a single-class quadruple-nucleoside/nucleotide regimen of trizivir and tenofovir

Simplified antiretroviral regimens have been developed with the aim of improving treatment adherence and quality of life of HIV-infected patients. The single-class triple-nucleoside reverse transcriptase inhibitor combination has contributed to the improvement of the management of HIV infection, especially in patients with adherence problems and special groups of the patient population. Such a regimen remains an alternative option because of lower virological efficacy compared with the preferred multiclass antiretroviral regimens. However, recently, a nucleoside reverse transcriptase inhibitor abacavir/lamivudine/zidovudine plus tenofovir has been investigated in both antiretroviral-naive patients and in heavily pre-treated patients, as well in the setting of simplification/switching strategies. This experimental combination could be a safe and attractive option that offers the advantages of limited toxicity, few drug interactions and the use of future treatment options with new drugs, especially for patients in later stages of infection.

An updated systematic overview of triple combination therapy in antiretroviral-naive HIV-infected adults

OBJECTIVE

To compare the effectiveness of three drug combination antiretroviral therapy (ART) in treatment-naive HIV-infected persons, and identify the predictors of responses.

DESIGN AND METHODS

Overview of trials identified by searching public domain publications and conference presentations. The three-drug combination therapy was defined as two nucleoside reverse transcriptase inhibitors (NRTI) or nucleotide and NRTI, and either: (1) a protease inhibitor (PI); (2) a non-nucleoside RTI (NNRTI); (3) a third NRTI; or (4) a ritonavir-boosted PI (BPI). Week 24 and 48 results for the proportions of patients with plasma HIV RNA levels < 400 and < 50 copies/ml, and change in CD4(+) cell counts were recorded.

RESULTS

Fifty-three trials met the entry criteria, and enrolled 14 264 patients into 90 treatment arms. Overall 55% of patients had plasma HIV RNA levels < 50 copies/ml at week 48 and this percentage increased with later publication dates. In unadjusted pairwise comparisons at week 48, significantly greater percentages of patients receiving NNRTI (64%) and BPI (64%) had RNA < 50 copies/ml than NRTI (54%) or PI (43%), and CD4(+) cell count increases were significantly greater in the BPI group (+200 cells/microl) than the PI (+179), NNRTI (+173), or NRTI (+161) groups. Pill count and percentage of patients with week 48 plasma HIV RNA levels < 50 copies/ml were correlated in the univariate analysis (P = 0.0053; r = -0.323), but pill count was not a significant predictor in the multivariate analyses. Drug class and baseline CD4(+) cell counts were significant predictors, but explained only a modest amount of the treatment effect, (R(2) = 0.355).

CONCLUSIONS

NNRTI and BPI-containing regimens offer superior virologic suppression over 48 weeks, supporting existing guidelines for the choice of initial ART. Pill count was not a consistent predictor of virologic suppression.

A prospective, 96-week study of the impact of Trizivir, Combivir/nelfinavir, and lamivudine/stavudine/nelfinavir on lipids, metabolic parameters and efficacy in antiretroviral-naive patients: effect of sex and ethnicity

OBJECTIVES

To compare the lipid and metabolic effects, efficacy, and safety of twice-daily regimens of Trizivir (abacavir 300 mg/lamivudine 150 mg/zidovudine 300 mg triple nucleoside tablet; TZV), Combivir (lamivudine 150 mg/zidovudine 300 mg combination tablet; COM)+nelfinavir (NFV), and stavudine (d4 T)+lamivudine (3TC)+NFV.

STUDY DESIGN

An international, phase 4, open-label, parallel-group, 34-centre study was conducted in 254 non-diabetic, antiretroviral-naive, HIV-infected out-patients with an HIV-1 RNA level of >1000 HIV-1 RNA copies/mL and < or =200,000 copies/mL and a CD4 cell count of >50 cells/microL.

METHODS

Patients were randomized 1 : 1 : 1 to TZV twice daily (n = 85), COM/NFV 1250 mg twice daily (n = 88), or d4T 40 mg+3TC 150 mg+NFV 1250 mg twice daily (n = 81) for 96 weeks. Treatments were compared using analysis of covariance (ANCOVA) with regard to changes from baseline in fasting lipids in the total population and in sex and ethnic subgroups. The proportions of patients achieving HIV-1 RNA <50 and <400 copies/mL were compared using a 95% confidence interval (CI) on the difference between proportions.

RESULTS

The study population was diverse (50% female, 40% black and 37% Hispanic). Mean baseline low-density lipoprotein (LDL) cholesterol was 99 mg/dL, HIV-1 RNA was 4.43 log10 copies/mL and CD4 cell count was 355 cells/microL. At week 96, fasting LDL cholesterol changed minimally in the TZV group [least square mean (LSM) change from baseline, -8 mg/dL], but increased with d4T/3TC/NFV and COM/NFV (+29 and +19 mg/dL, respectively; P < 0.001 versus TZV). Week 96 LDL-cholesterol levels were significantly lower in the TZV group than in the other two treatment groups in women and men and lower than in the d4T/3TC/NFV group in Hispanic and black patients. In black patients, the week-96 LSM change from baseline in LDL cholesterol was significantly less with TZV than with d4T/3TC/NFV (+1 vs+39 mg/dL; P = 0.003). Total cholesterol >200 mg/dL occurred in a smaller proportion of patients receiving TZV (30%) compared with COM/NFV (50%) or d4T/3TC/NFV (60%; P = 0.005 vs TZV). High-density lipoprotein (HDL) cholesterol did not change markedly with any treatment. Although triglycerides increased, they changed least in women and Hispanic patients receiving TZV. Virological and CD4 responses to the treatments were similar in the total population and in the subgroups. Diarrhoea was reported more often in the NFV arms and nausea in the ZDV arms.

CONCLUSIONS

Over 96 weeks, TZV twice daily has significantly less effect on LDL cholesterol than COM/NFV or d4T/3TC/NFV twice daily, especially in women and black patients, and is associated with similar virological and CD4 responses.

Current status of antiretroviral therapy

At present, there are 22 FDA-approved antiretroviral agents, which are categorised into four classes of drugs. Several others are in various stages of basic and clinical development. The authors of this paper review the general characteristics of each class of antiretrovirals, as well as individual investigational agents that are in advanced clinical development. A brief synopsis of US and WHO antiretroviral treatment guidelines is also provided.

Pesquisas brasileiras biomédicas e epidemiológicas face às metas da UNGASS

O foco do estudo é a resposta brasileira em Ciência, Tecnologia e Inovação às metas formuladas no documento da UNGASS. Foram analisados os itens 70-73 que integram o documento Draft Declaration of Commitment for the UNGASS on HIV/AIDS, 2001, que definem metas para a Ciência, Tecnologia e Inovação em HIV/Aids. Os principais tópicos listados nesses itens foram operacionalizados sob a forma de "palavras-chave", de modo a orientar buscas sistemáticas nos bancos de dados padrão em biomedicina, incluindo ainda o Web of Science, nas suas subdivisões referentes às ciências naturais e sociais. O sucesso da pesquisa brasileira no âmbito da caracterização e isolamento do HIV-1 é inegável. Estudos vacinais fases II/III têm sido desenvolvidos no Rio de Janeiro, Belo Horizonte e São Paulo. O monitoramento da resistência primária teve estudos empíricos desenvolvidos em populações específicas, por meio da "Rede Brasileira em Monitoramento da Resistência do HIV". No âmbito do monitoramento da resistência secundária, destacaram-se iniciativas como a Rede Nacional de Genotipagem. Dois sistemas nacionais, o Sistema de Informações de Mortalidade e o Sistema de Informações de Agravos de Notificação - Aids e alguns estudos de maior abrangência têm dado origem a trabalhos sobre tendências da epidemia. A produção de medicamentos genéricos de qualidade e sua distribuição gratuita aos pacientes foram destacadas. O Brasil tem implementado uma resposta consistente e diversificada no âmbito do HIV/Aids, com estudos referentes ao desenvolvimento de vacinas, novos medicamentos e monitoramento da epidemia.

Effectiveness and Safety of Abacavir, Lamivudine, and Zidovudine in Antiretroviral Therapy-Naive HIV-Infected Patients

OBJECTIVE

To analyze the safety and effectiveness of abacavir, lamivudine, and zidovudine (ABC/3TC/ZDV) in antiretroviral therapy (ART)-naive HIV-infected patients.

DESIGN

Retrospective observational cohort study.

METHODS

We analyzed all consecutive ART-naive HIV-infected patients who initiated ABC/3TC/ZDV in 71 centers throughout Spain and had a clinical visit and laboratory data at least 16 weeks after initiating this regimen. We assessed safety, mortality, new AIDS-defining conditions (ADCs) and treatment failure, the latter defined by any of the following: (1) reduction in plasma HIV-1 viral load (pVL) <1 log during the first 12 weeks of ART, unless it was less than the lower limit of quantification (LOQ); (2) failure to achieve a pVL <LOQ after 24 weeks of ART; and (3) rebound to 2 consecutive pVLs > or = LOQ after achieving a pVL <LOQ.

RESULTS

A total of 730 patients were included, median patient age was 37 years, prior ADCs occurred in 20%, median pVL was 4.76 log, and median CD4 count was 255 cells/mm; 109 (14.9%) patients had <100 CD4 cells/mm. After a median follow-up of 50.5 weeks (interquartile ratio: 28-78), 104 (14.25%) patients discontinued therapy because of adverse events and 36 (4.93%) had a suspected hypersensitivity reaction to ABC. The frequency of treatment failure according to an intention-to-treat (ITT) analysis of observed data was 14.4%. In a more rigorous approach considering losses to follow-up and interruptions or switches of therapy as failures, however, the frequency of treatment failure was 22.92%. Factors independently associated with treatment failure by observed data ITT analysis were adherence <90% (hazard ratio [HR] = 4.248, 95% confidence interval [CI]: 2.640 to 6.833), methadone use (HR = 2.116, 95% CI: 1.180 to 3.797), baseline pVL (HR = 1.651, 95% CI: 1.190 to 2.292 per log), and prior ADC (HR = 1.639, 95% CI: 1.009 to 2.662).

CONCLUSION

The triple-nucleoside regimen of ABC/3TC/ZDV is a reasonable option for ART-naive patients with a pVL <100,000 copies/mL in whom, for any reason, preferred regimens are not advisable, even in patients with a baseline CD4 cell count <100 cells/mm.

Triple-nucleoside analog antiretroviral therapy: is there still a role in clinical practice? A review

The development and widespread clinical use of coformulated abacavir/lamivudine/zidovudine (ABC/3TC/ZDV) as Trizivir represented an important advance in the management of HIV-infected patients, especially those with adherence challenges. With a low pill burden, no food restrictions, limited drug-drug interactions, and a favorable resistance profile, ABC/3TC/ZDV remains an alternative option in the US Department of Health and Human Services Consensus Panel Guidelines as initial treatment in antiretroviral-naive patients. Recent data have shown ABC/3TC/ZDV to be less efficacious in suppressing and/or maintaining suppression of virologic replication compared with efavirenz-containing antiretroviral therapy. Although triple-nucleoside/nucleotide reverse transcriptase inhibitor (t-NRTI) combinations that do not contain a thymidine analog (ZDV or stavudine) have recently shown high virologic failure rates in clinical trials and clinical practice, t-NRTI regimens containing a thymidine analog have consistently been shown to be efficacious.

Substituting abacavir for hyperlipidemia-associated protease inhibitors in HAART regimens improves fasting lipid profiles, maintains virologic suppression, and simplifies treatment

Background

Hyperlipidemia secondary to protease inhibitors (PI) may abate by switching to anti-HIV medications without lipid effects.

Method

An open-label, randomized pilot study compared changes in fasting lipids and HIV-1 RNA in 104 HIV-infected adults with PI-associated hyperlipidemia (fasting serum total cholesterol >200 mg/dL) who were randomized either to a regimen in which their PI was replaced by abacavir 300 mg twice daily (n = 52) or a regimen in which their PI was continued (n = 52) for 28 weeks. All patients had undetectable viral loads (HIV-1 RNA <50 copies/mL) at baseline and were naïve to abacavir and non-nucleoside reverse transcriptase inhibitors.

Results

At baseline, the mean total cholesterol was 243 mg/dL, low density lipoprotein (LDL)-cholesterol 149 mg/dL, high density lipoprotein (HDL)-cholesterol 41 mg/dL, and triglycerides 310 mg/dL. Mean CD4+ cell counts were 551 and 531 cells/mm³ in the abacavir-switch and PI-continuation arms, respectively. At week 28, the abacavir-switch arm had significantly greater least square mean reduction from baseline in total cholesterol (-42 vs -10 mg/dL, P < 0.001), LDL-cholesterol (-14 vs +5 mg/dL, P = 0.016), and triglycerides (-134 vs -36 mg/dL, P = 0.019) than the PI-continuation arm, with no differences in HDL-cholesterol (+0.2 vs +1.3 mg/dL, P = 0.583). A higher proportion of patients in the abacavir-switch arm had decreases in protocol-defined total cholesterol and triglyceride toxicity grades, whereas a smaller proportion had increases in these toxicity grades. At week 28, an intent-to treat: missing = failure analysis showed that the abacavir-switch and PI-continuation arms did not differ significantly with respect to proportion of patients maintaining HIV-1 RNA <400 or <50 copies/mL or adjusted mean change from baseline in CD4+ cell count. Two possible abacavir-related hypersensitivity reactions were reported. No significant changes in glucose, insulin, insulin resistance, C-peptide, or waist-to-hip ratios were observed in either treatment arm, nor were differences in these parameters noted between treatments.

Conclusion

In hyperlipidemic, antiretroviral-experienced patients with HIV-1 RNA levels <50 copies/mL and CD4+ cell counts >500 cells/mm³, substituting abacavir for hyperlipidemia-associated PIs in combination antiretroviral regimens improves lipid profiles and maintains virologic suppression over a 28-week period, and it simplifies treatment.

Predictors of adherence and virologic outcome in HIV-infected patients treated with abacavir- or indinavir-based triple combination HAART also containing lamivudine/zidovudine

OBJECTIVES

To compare dosing convenience and adherence with abacavir (ABC) 300 mg plus a fixed-dose lamivudine 150 mg/zidovudine 300 mg combination tablet (COM) twice daily versus indinavir (IDV) plus COM twice daily in treatment-naïve, HIV-1-infected adults; and to evaluate the association among difficulty taking antiretroviral regimens, adherence, and virologic efficacy.

METHODS

An open-label, randomized, multicenter, international study compared the COM/ABC and IDV/COM regimens with respect to self-reported adherence and regimen convenience over 48 weeks. Logistic regression analysis (LRA) was done on a patient sub-sample from both groups to evaluate predictors of adherence and virologic response at last time-point on randomized therapy (LTORT).

RESULTS

The study population was diverse with respect to ethnicity (38% Asian, 27% Hispanic, 28% white, 3% black, 4% other) and gender (39% women, 61% men). Baseline median HIV-1 RNA was 4.80 log(10) copies/mL and CD4+ cell count was 315 cells/mm(3). Of 329 patients who were randomized and received treatment, 315 (96%) provided adherence data. Significantly more patients in the ABC/COM group than in the IDV/COM group reported > or = 95% adherence to therapy (76 vs 58%, p < 0.001) and no difficulty in taking their regimen (91 vs 61%, p < 0.001). In both groups, the highest probability of HIV-1 RNA < 400 copies/mL occurred when median adherence was > or = 95%. The probability of HIV-1 RNA < 400 copies/mL declined more rapidly in the IDV/COM group as adherence rates decreased. LRA showed that no difficulty taking any of the drugs in the regimen, ABC/COM treatment group, and male gender were independent significant predictors of > or = 95% adherence (p < 0.05). Median adherence and baseline HIV-1 RNA were significant predictors of HIV-1 RNA < 400 copies/mL (p < 0.05).

CONCLUSIONS

Patients reported greater ease of use and superior adherence to ABC/COM than IDV/COM. Patient-reported difficulty taking drugs in a regimen was predictive of reduced adherence, and both of the latter factors were predictive of poorer virologic outcome. Adherence levels of > or = 95% in both treatment groups maximized the probability of patients achieving an HIV-1 RNA < 400 copies/mL.