A randomized study comparing a three- and four-drug HAART regimen in first-line therapy (QUAD study)

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

OBJECTIVE

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

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

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

STUDY SELECTION

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

REVIEW METHODS

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

RESULTS

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

CONCLUSION

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

Long-term immune and virological response in HIV-infected patients receiving antiretroviral therapy

WHAT IS KNOWN AND OBJECTIVE

The trajectory of HIV viral load and CD4 count and the occurrence of clinical events are primary considerations in the evaluation of antiretroviral therapy (ART) success or failure, yet a large number of studies do not describe these events from the point of therapy initiation. This study aims to describe the virological and immune response to ART and factors associated with immune and virological success in outpatients from a HIV/AIDS clinic in southern Brazil from therapy initiation.

METHODS

Longitudinal observational with ambidirectional data collection study with adult patients followed for at least 12 months after enrolment. Outcomes include (i) favourable immune response, defined as CD4 count ≥200 cells/mm³; and (ii) virological success, defined as viral load below the limit of detection (50 copies/mL).

RESULTS

The study included 332 patients, mostly men (63%), whose mean age was 40 (±10) years and with median family income of BR$ 490·00 per month (IQR: 350-875). Before starting ART, 43% of patients had indications of stable immune status (CD4 count ≥200 cells/mm³); the median CD4 count was 179 cells/mm³ (IQR: 93·5, 267) and increased to 379·5 cells/mm³ (IQR: 236·5, 591·3). The proportion of patients with CD4 count ≥200 cells/mm³ increased from 76% to 83%, and with undetectable viral load (UVL) increased from 51·7% to 73%. Factors associated with immune success at the end of study follow-up were as follows: female gender, pretreatment CD4 count ≥200 cells/mm³, previous UVL (measured when started prospective follow-up) and treatment with three drugs compared with ≥4. Factors associated with virological success were as follows: UVL (measured when started prospective follow-up) and use of three drugs compared with ≥4.

WHAT IS NEW AND CONCLUSIONS

Results of this study show that a large proportion (73%) of patients have rapid and successful immune and virological responses to ART and that factors which predict this response include starting ART early, whereas viral load is low and CD4 count is high, with fewer drugs. These results further support the ongoing need for ongoing programmes to increase early HIV testing, early linkage to and treatment with ART, and increased viral suppression.

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.

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.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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.

Induction maintenance concept for HAART as initial treatment in HIV infected infants

Background

Early initiated antiretroviral therapy (ART) in HIV infected infants leads to improved long-term viral suppression and survival. Guidelines recommend initiating therapy with a triple ART consisting of two nucleoside reverse transcriptase inhibitors (NRTIs) and either one additional non-nucleoside reverse transcriptase inhibitor (NNRTI) or a protease inhibitor (PI). Compared to older children and adults, viral relapse is seen more frequently in infants receiving triple ART. We now address the possibility of a more potent ART with a quadruple induction and triple maintenance therapy.

Methods

We examine the longitudinal course in four HIV infected infants, who were referred from other centers and could not be recruited to multicentre trials. We introduced ART initially consisting of two NRTIs, one NNRTI and one PI and later discontinued the PI at the age of 12 months maintaining a triple regime consisting of two NRTIs and one NNRTI.

Results

Provided that therapy adherence was maintained we observed an effective sustained decline of viral load and significant CD4 cell reconstitution even after switching to a triple regime. No drug associated toxicity was seen.

Conclusion

We suggest that a four drug therapy might be a possible initial therapy option in HIV infected infants, at least in those with a high viral load, followed by a maintenance triple regime after 12 months of therapy.

Looking for an active conformation of the future HIV type-1 non-nucleoside reverse transcriptase inhibitors

HIV type-1 (HIV-1) non-nucleoside reverse transcriptase inhibitors (NNRTIs) are key drugs of highly active antiretroviral therapy (HAART) in the clinical management of AIDS/HIV infection. NNRTI-based HAART regimes effectively suppress viral reproduction, are not cytotoxic and show favourable pharmacokinetic properties. First-generation NNRTIs suffer the rapid selection of viral variants, hampering the binding of inhibitors into the reverse transcriptase (RT) non-nucleoside binding site (NNBS). Efforts to improve these first inhibitors led to the discovery of second-generation NNRTIs that proved to be effective against the drug-resistant mutant HIV-1 strains. The success of such agents launched a new season of NNRTI design and synthesis. This paper reviews the characteristics of second-generation NNRTIs, including etravirine, rilpivirine, RDEA-806, UK-453061, BIRL 355 BS, IDX 899, MK-4965 and HBY 097. In particular, the binding modes of these inhibitors into the NNBS of the HIV-1 RT and the most clinically relevant mutant RTs are analysed and discussed.

Indolylarylsulfones bearing natural and unnatural amino acids. Discovery of potent inhibitors of HIV-1 non-nucleoside wild type and resistant mutant strains reverse transcriptase and coxsackie B4 virus

New potent indolylarylsulfone (IAS) HIV-1 NNRTIs were obtained by coupling natural and unnatural amino acids to the 2-carboxamide and introducing different electron-withdrawing substituents at position 4 and 5 of the indole nucleus. The new IASs inhibited the HIV-1 replication in human T-lymphocyte (CEM) cells at low/subnanomolar concentration and were weakly cytostatic. Against the mutant L100I, K103N, and Y181C RT HIV-1 strains in CEM cells, sulfones 3, 4, 19, 27, and 31 were comparable to EFV. The new IASs were inhibitors to Coxsackie B4 virus at low micromolar (2-9 microM) concentrations. Superimposition of PLANTS docked conformations of IASs 19 and 9 revealed different hydrophobic interactions of the 3,5-dimethylphenyl group, for which a staking interaction with Tyr181 aromatic side chain was observed. The binding mode of 19 was not affected by the L100I mutation and was consistent with the interactions reported for the WT strain.

Indolyl Aryl Sulfones as HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors: Role of Two Halogen Atoms at the Indole Ring in Developing New Analogues with Improved Antiviral Activity

Indolyl aryl sulfones bearing the 4,5-difluoro (10) or 5-chloro-4-fluoro (16) substitution pattern at the indole ring were potent inhibitors of HIV-1 WT and the NNRTI-resistant strains Y181C and K103N-Y181C. These compounds were highly effective against the 112 and the AB1 strains in lymphocytes and inhibited at nanomolar concentration the multiplication of the IIIBBa-L strain in macrophages. Compound 16 was exceptionally potent against RT WT and RTs carrying the K103N, Y181I, and L100I mutations.

Efavirenz: a review

Efavirenz is a non-nucleoside reverse transcriptase inhibitor that in most treatment guidelines is recommended to be taken combined with two nucleoside analogue reverse transcriptase inhibitors, as a preferred first-line regimen for the treatment of HIV-1 infection. The antiretroviral efficacy of efavirenz-based combination regimens is good, as has been demonstrated in many clinical trials. Efavirenz has a long plasma half-life, which allows for once-daily dosing, but, as a consequence of this and the low genetic barrier, it is also prone to select for viral resistance when adherence to therapy is suboptimal. The most frequently encountered side effects are neuropsychiatric symptoms. These side effects are usually transient, but have been shown to persist for up to 2 years after initiation of therapy in some patients. This review outlines important and recent pharmacological and clinical data, which explain why efavirenz became a component of preferred treatment regimens today.

Fixed-dose combination of abacavir, lamivudine and zidovudine for HIV therapy

Triple-nucleoside therapy with abacavir (ABV)/lamivudine (3TC)/zidovudine (ZDV) combination tablets provides simple, nonfood-dependent, twice-daily, well-tolerated therapy with the potential to improve long-term adherence at a lower cost than other triple-drug regimens. Of all the triple nucleoside reverse transcriptase inhibitor combinations currently available, ABV/3TC/ZDV is most extensively studied. Although ABV/3TC/ZDV is possibly less potent than other treatment options when used alone, other attributes described in this review make it an attractive option for selected patients. This combination spares the use of protease inhibitors and their associated side effects, such as metabolic abnormalities, which may contribute to premature cardiovascular disease. Furthermore, by using only one drug class, it may maintain a greater number of future treatment options. Data from ongoing clinical trials may result in expanding the use of ABV/3TC/ZDV as a component of multidrug, highly active antiretroviral therapy regimens.

Relationship Between Antiretroviral Prescribing Patterns and Treatment Guidelines in Treatment-Naive HIV-1-Infected US Veterans (1992-2004)

OBJECTIVE

To analyze temporal patterns of antiretroviral (ARV) prescribing practices relative to nationally defined guidelines in treatment-naive patients with HIV-1 infection.

DESIGN

Retrospective cohort study.

METHODS

We evaluated ARV prescribing patterns among ARV treatment-naive veterans who were receiving care within the US Department of Veterans Affairs (VA) from 1992 through 2004 in comparison to evolving adult HIV-1 treatment guidelines.

RESULTS

A total of 15,934 patients initiated ARV treatment. Since 1999, >94% of patients initiated at least a 3-ARV medication combination, although the percentage of patients who initiated a guideline "preferred" or "alternative" regimen never rose to greater than 72% and was significantly associated with being black and with region of care. After 1999, 20% of patients started 4 or more active ARV agents in combination, which was significantly associated with lower baseline CD4 cell count, higher viral load, and receiving care in the western United States. The proportion of patients receiving guideline "not recommended" regimens (virologically undesirable or overlapping toxicities) was <1% after 1997. VA prescribing trends generally predated guideline recommendations by 6 to 12 months.

CONCLUSIONS

VA prescribing patterns for ARV initiation adhere to treatment guidelines that maximize safety. Guidelines designed to maximize efficacy were not followed as stringently. Evaluating clinical practice patterns against contemporary treatment guidelines can inform guideline development.

An Open-Label, Randomized Comparative Pilot Study of a Single-Class Quadruple Therapy Regimen versus a 2–Class Triple Therapy Regimen for Individuals Initiating Antiretroviral Therapy

Objective

To examine the antiviral potency and tolerability profile of a single-class four drug (quadruple) nucleoside reverse transcriptase inhibitor (NRTI) regimen compared with a 2-class standard-of-care regimen.

Methodology

A three-centre, randomized, open-label comparative pilot study of zidovudine/lamivudine/efavirenz (triple) versus abacavir/lamivudine/zidovudine/tenofovir (quadruple) therapy in HIV-1-infected, treatment-naive individuals. Both regimens were taken without regard to food and consisted of a twice-daily regimen and 3 pills/day. The study power was based on time-weighted average changes in HIV-1 RNA load.

Results

A total of 114 individuals (56 triple, 57 quadruple) received at least one dose of medication. Patients were well matched at baseline for viral load (mean 5.26 log10 versus 5.13 log10, respectively) and CD4 cell count (median 193 versus 153 cells/mm3, respectively). The two regimens performed similarly with regards to all endpoints. At week 48, by intention-to-treat, missing=failure analysis, 68% of triple- and 67% of quadruple-drug treated patients had an HIV-1 RNA <50 copies/ml ( P>0.05). On-treatment analysis showed 40/40 (100%) of triple- and 39/40 (97.5%) of quadruple-drug treated patients ( P=0.996) had responded to <50 copies/ml. No unexpected adverse events were reported. Changes in total cholesterol and triglycerides were modest but significantly favoured the quadruple therapy regimen at multiple time points.

Conclusion

This pilot study suggests a quadruple NRTI-based regimen provides similar antiviral potency, tolerability and administrative characteristics to a 2-class triple therapy regimen. These findings should be confirmed in a more fully powered study. Potent quadruple NRTI-based regimens may have advantages for some individuals with regards to salvageability, tolerability and drug interactions.

Adherence to trizivir and tenofovir as a simplified salvage regimen is associated with suppression of viraemia and a decreased cholesterol

BACKGROUND

Treatment failure during highly active antiretroviral therapy (HAART) is ultimately common and associated with the development of resistance mutations. Trizivir (zidovudine/lamivudine/abacavir) and tenofovir disoproxil fumarate may improve adherence and enhance virological suppression in individuals who have failed previous regimens.

METHODS

Individuals were identified who had failed previous HAART and who were then prescribed trizivir and tenofovir. Viral load and genotypic information were obtained to assess virological response.

RESULTS

One hundred and twenty-two individuals were identified from a database containing 5883 patients. In a last observation carried forward intention to treat analysis, 34% of individuals achieved an undetectable viral load of <50 copies/mL at 1 year. Of those who were able to remain on treatment for 1 year, 65% achieved undetectability. We observed no effect regarding previous regimens on viral outcome. Accumulation of TAMs (thymidine analogue mutations) was associated with a decrease in the number of patients achieving an undetectable viral load (with <2 TAMs present 38% of patients developed undetectable viral loads, > or =1;2 TAMs 17% undetectable; P = 0.03). Using the mean cell volume as a measure of compliance, those with higher values were more likely to achieve a viral load <50 copies/mL (P = 0.04). A beneficial effect on cholesterol was noted regardless of virological outcome.

CONCLUSIONS

In compliant heavily pre-treated individuals with less than 2 TAMs, salvage therapy with trizivir and tenofovir is associated with suppression of viraemia and an improved lipid profile.