Switch from enfuvirtide to raltegravir in virologically suppressed HIV-1 infected patients: effects on level of residual viremia and quality of life

Prevalence and risk of residual viremia after ART in low- and middle-income countries: A cross-sectional study

ABSTRACT

In order to design effective strategies to eradicate the HIV, an understanding of persistent viral reservoirs is needed. Many studies have demonstrated HIV residual viremia prevalence in high income countries, data from low- and middle-income countries (LMIC) are limited. We assessed the prevalence, and factors associated with residual viremia in people with HIV (PWH), who were virally-suppressed on antiretroviral therapy (ART) in LMIC. We also compared residual viremia prevalence between the LMIC and US.This is a cross-sectional, retrospective study that utilized stored specimen samples from the AIDS clinical trials group (ACTG) studies A5175 and A5208. The last available sample among participants with plasma HIV RNA < 400 copies/mL for ≥3 years were tested by the HIV molecular and monitoring core gag (HMMCgag) single copy assay (SCA). Residual viremia was defined as detectable if ≥1 copy/mL. Spearman's correlation and multivariable stepwise logistic regression were used to assess associations of various factors with SCA.A total of 320 participants, 246 (77%) from LMIC and 74 (23%) from US, were analyzed. Median (IQR) age was 33 (2840) years; baseline CD4 166 (88,230) cells/mm3; HIV RNA 5.0 (4.5, 5.3) log10 copies/mL; duration of viral suppression 3.4 (3.1, 4.0) years and 48% were male. In 85 participants with information available, 53% were subtype C, 42% subtype B and 5% other subtypes. Overall prevalence of residual viremia was 57% [95% CI, 52-63] with 51% [40-63] in US and 59% [53-65] in LMIC. Among participants with detectable SCA, the median (IQR) HIV RNA was 3.8 (2.2, 8.1) copies/mL. The multivariable model conducted in LMIC participants showed that higher baseline HIV RNA was associated with detectable residual RNA (OR 2.9, 95% CI 1.8, 4.6 for every log10 increase, P < .001). After including both US and LMIC in the final model, baseline HIV RNA remained significant. No difference in SCA detestability was found between US and LMIC sites (OR 1.1 [0.6, 2.0], P = .72) after adjusting for baseline RNA and parent study.The prevalence of residual viremia between both groups were not different and more than half of the participants had detectable viremia. Higher baseline HIV RNA was independently associated with residual viremia.

Modifying Antiretroviral Therapy in Virologically Suppressed HIV-1-Infected Patients

HIV-1-infected patients with suppressed plasma viral loads often require changes to their antiretroviral (ARV) therapy to manage drug toxicity and intolerance, to improve adherence, and to avoid drug interactions. In patients who have never experienced virologic failure while receiving ARV therapy and who have no evidence of drug resistance, switching to any of the acceptable US Department of Health and Human Services first-line therapies is expected to maintain virologic suppression. However, in virologically suppressed patients with a history of virologic failure or drug resistance, it can be more challenging to change therapy while still maintaining virologic suppression. In these patients, it may be difficult to know whether the discontinuation of one of the ARVs in a suppressive regimen constitutes the removal of a key regimen component that will not be adequately supplanted by one or more substituted ARVs. In this article, we review many of the clinical scenarios requiring ARV therapy modification in patients with stable virologic suppression and outline the strategies for modifying therapy while maintaining long-term virologic suppression.

Prolonged persistence of a novel replication-defective HIV-1 variant in plasma of a patient on suppressive therapy

BACKGROUND

Cell-free residual HIV-1 virions (RVs) persist in plasma below 20-50 vRNA copies/ml in most patients on suppressive antiretroviral therapy (ART). How RVs are produced in the body during therapy is not fully clear. In this study, we have attempted to characterize these viruses of an ART-treated patient in vitro in order to gain insights into the mechanism of their production in vivo.

METHODS

We have reconstructed almost the entire genomes of RVs as DNA forms using the patient's residual plasma vRNA by an overlapping RT-nested PCR method, and then sequence-analyzed the cloned genomes and tested them for their biological activities in vitro.

RESULTS

We found that the reconstructed molecular clones of RVs lacked antiretroviral drug-resistant mutations, as well as G-to-A hypermutations. The vDNA clones, when transfected into TZM-bl cells, released HIV-p24 into the culture media at extremely low levels. This low-level virus production was found to be due to the presence of a unique mutation (GU-to-GC) in the conserved 5'-major splice donor (MSD) motif of the corresponding vRNAs. We found that the incorporation of this point mutation by itself could cause defects in the replication of a standard HIV strain (JRCSF) in vitro. However, this novel viral variant was intermittently detected at 5 of 7 time-points in the patient's plasma over a period of 39 months during therapy.

CONCLUSIONS

This is the first identification of a natural point mutation (GU-to-GC) in the conserved 5'-MSD motif of HIV genomic RNA. The intermittent but prolonged detection of this replication-defective HIV variant in the patient's plasma among other viral populations strongly suggests that this variant is released from highly stable productively infected cells present in vivo during therapy. The potential implication of this observation is that the elimination of such productively infected cells that contribute to residual viremia during suppressive therapy could be an important first step towards achieving a cure for HIV.

HIV-1 Very Low Level Viremia Is Associated with Virological Failure in Highly Active Antiretroviral Treatment-Treated Patients

The aim of this study was to evaluate the impact of HIV-1 very low-level viremia (<50 copies/ml) on the 2-year risk of virological failure. A retrospective analysis including HIV-positive patients presenting two consecutive HIV RNA below 50 copies/ml (outpatient clinic in Italy, first semester of 2010) was performed. HIV RNA was measured through real time polymerase chain reaction (PCR) assay CAP/CTM HIV-1 version 2.0 (detection limit: 20 copies/ml) and stratified as undetectable RNA ("Target Not Detected", TND), <20 copies/ml, 20-50 copies/ml. After 96 weeks virological failure was defined as two consecutive viral loads above 50 copies/ml. Log-rank tests and a multivariate Cox proportional hazard model were used for univariate and multivariate analysis. A total of 1,055 patients (71.4% male, 87.4% white, aged 46.7 years) were included: nadir and current CD4 cell counts were 203 cells/mm(3) (106-292) and 554 cells/mm(3) (413-713.5). HIV RNA was undetectable in 781 patients (74%), <20 copies/ml in 190 patients (18%) and 20-50 copies/ml in 84 patients (8%). Virological failure was observed in 81 patients (7.7%); at multivariate analysis detectable RNA at baseline (p=0.017), HCV infection (p=0.020), more than three pills in the regimen (p=0.003), and duration of HIV RNA <50 copies/ml below 2 years (p<0.001) were independently associated with virological failure. In 14 patients newly selected resistance-associated mutations were observed. Undetectable HIV RNA by real-time PCR is significantly associated with a lower 2-year risk of virological failure along with Ab HCV negativity, longer viral control, and lower pill burden. Studies investigating the management of residual viremia under antiretroviral treatment are warranted.

Potential implication of residual viremia in patients on effective antiretroviral therapy

The current antiretroviral therapy (ART) has suppressed viremia to below the limit of detection of clinical viral load assays; however, it cannot eliminate viremia completely in the body even after prolonged treatment. Plasma HIV-1 loads persist at extremely low levels below the clinical detection limit. This low-level viremia (termed "residual viremia") cannot be abolished in most patients, even after the addition of a new class of drug, i.e., viral integrase inhibitor, to the combined antiretroviral regimens. Neither the cellular source nor the clinical significance of this residual viremia in patients on ART remains fully clear at present. Since residual plasma viruses generally do not evolve with time in the presence of effective ART, one prediction is that these viruses are persistently released at low levels from one or more stable but yet unknown HIV-1 reservoirs in the body during therapy. This review attempts to emphasize the source of residual viremia as another important reservoir (namely, "active reservoir") distinct from the well-known latent HIV-1 reservoir in the body, and why its elimination should be a priority in the effort for HIV-1 eradication.

Inhibiting the HIV integration process: past, present, and the future

HIV integrase (IN) catalyzes the insertion into the genome of the infected human cell of viral DNA produced by the retrotranscription process. The discovery of raltegravir validated the existence of the IN, which is a new target in the field of anti-HIV drug research. The mechanism of catalysis of IN is depicted, and the characteristics of the inhibitors of the catalytic site of this viral enzyme are reported. The role played by the resistance is elucidated, as well as the possibility of bypassing this problem. New approaches to block the integration process are depicted as future perspectives, such as development of allosteric IN inhibitors, dual inhibitors targeting both IN and other enzymes, inhibitors of enzymes that activate IN, activators of IN activity, as well as a gene therapy approach.

Inhibiting the HIV integration process: past, present, and the future

HIV integrase (IN) catalyzes the insertion into the genome of the infected human cell of viral DNA produced by the retrotranscription process. The discovery of raltegravir validated the existence of the IN, which is a new target in the field of anti-HIV drug research. The mechanism of catalysis of IN is depicted, and the characteristics of the inhibitors of the catalytic site of this viral enzyme are reported. The role played by the resistance is elucidated, as well as the possibility of bypassing this problem. New approaches to block the integration process are depicted as future perspectives, such as development of allosteric IN inhibitors, dual inhibitors targeting both IN and other enzymes, inhibitors of enzymes that activate IN, activators of IN activity, as well as a gene therapy approach.

Short communication: Effectiveness at 48 weeks of switching from enfuvirtide to raltegravir in virologically suppressed multidrug-resistant HIV type 1-infected patients in a Brazilian cohort

The effectiveness of switching from enfuvirtide to raltegravir in HIV-1-infected patients on a suppressive antiretroviral regimen has been poorly studied in the clinical practice of developing countries. We conducted a multicenter retrospective cohort study in HIV-1-infected, multidrug-experienced adults (≥18 years old) with plasma HIV-1-RNA <400 copies/ml for at least 4 months on an enfuvirtide-containing therapy between 2005 and 2010, in whom the attending physician switched from enfuvirtide to raltegravir. Effectiveness endpoints were measured at week 48 after switch. Analyses were conducted on an intent-to-treat basis and two strategies for handling missing outcome data were used (hereafter, strategies 1 and 2). Overall, 87 patients were eligible for analysis. At baseline, the median CD4(+) T cell count was 400 cells/μl and 91.9% of patients had <50 HIV-1-RNA copies/ml. At week 48, the proportions of patients with plasma HIV-1-RNA <50 and <400 copies/ml were, respectively, 86.2% (95% CI=77.1; 92.7%) and 88.5% (95% CI=79.9; 94.3%) (strategies 1 and 2) and 89.7% (95% CI=81.3; 95.2%) and 90.8% (95% CI=82.7; 95.9%) (strategies 1 and 2). This was a -10.3% (95% CI=-2.8; -17.9%) and -9.2% (95% CI=-2; -16.4%) difference from baseline in the proportion of patients with plasma HIV-1-RNA <400 copies/ml. The median increase in CD4(+) T cell counts was 41 and 64 cells/μl (p<0.001) (strategies 1 and 2). No patient withdrew raltegravir or developed opportunistic infections, but one was diagnosed with HIV-related dementia. In conclusion, switching from enfuvirtide to raltegravir in patients on a virologically suppressive regimen is an effective strategy even in a Brazilian clinical setting.

Single-copy quantification of HIV-1 in clinical samples

HIV replication in humans proceeds with substantial viral RNA levels in plasma. Antiretroviral therapy results in suppression but not eradication of HIV infection. Continuous therapy is essential for durable clinical responses. Discontinuing antiretroviral therapy results in prompt rebound in viremia. The source of HIV during suppressive therapy and mechanisms of persistence remain uncertain. Sensitive assays for HIV have been useful in quantifying viremia in response to antiretroviral therapy and in experimental studies of drug intensification, drug simplification, and potential anatomic sanctuary site investigations. As clinical eradication strategies move forward, robust, sensitive quantitative assays for HIV at low levels represent essential laboratory support modalities. Here we describe in detail an assay for HIV-1 RNA with single-copy sensitivity.

Health-related quality of life assessment after antiretroviral therapy: a review of the literature

Antiretroviral (ARV) treatment for HIV infection has resulted in significant improvement in immunologic and virologic parameters, as well as a reduction in AIDS-defining illnesses and death. Over 25 medications are approved for use, usually in combination regimens of three or four ARVs. Several ARVs are now available as combinatorial products, which have been associated with better adherence. However, while ARV therapy has prolonged life, ARVs also pose a challenge for quality of life as they can cause significant side effects in addition to the potential for drug toxicity and interaction. Given the many complications, side effects and symptoms of HIV/AIDS in addition to associated medical and psychiatric co-morbidities, the need to understand and assess how these interactions may affect health-related quality of life (HRQOL) has grown. Numerous instruments (some validated, others not) are available and have been applied to understanding how ARV treatment affects HRQOL in those with HIV infection, both in clinical trials and clinical practice. In general, ARV treatment improves HRQOL, but this is dependent on the population being studied, the HRQOL instrument being used and the timeframe during which HRQOL has been studied. This article provides a review of the literature on quality of-life assessment as it relates to ARV treatment in developed countries and briefly reviews the HRQOL instruments used, how they have been applied to ARV utilization, and where future research should be applied in HRQOL assessment and HIV infection.

Monitoring the emergence of resistance mutations in patients infected with HIV-1 under salvage therapy with raltegravir in Rio de Janeiro, Brazil: a follow-up study

The present study describes a follow-up of a prospective and observational cohort of patients infected with HIV-1 and treated with raltegravir for salvage therapy in Brazil. Two groups of patients were analyzed: switching from T20 to RAL (Group 1, n = 9) and salvage therapy containing RAL (Group 2, n = 10). Blood samples were drawn for CD4(+) T-cell counts and HIV-1 viral load determinations. Protease, reverse transcriptase, and integrase genotyping were performed at baseline and at the time of virologic failure. CD4(+) T-cells increased at 6 and 12 months in both groups; HIV-1 viral load was continuously suppressed for Group 1, and for Group 2 it significantly decreased after starting a RAL-containing regimen. Three out of 10 patients from Group 2 could not suppress HIV-1 viral load. The mutations Q148H + G140S were observed for two patients and for the third patient only mutations to PR/RT inhibitors were detected. The genotypic sensitivity score (GSS) was analyzed for all patients of Group 2 and both patients who developed resistance to raltegravir presented a GSS < 2.0 for the RAL-containing scheme, which could be associated to the lack of effectiveness of the proposed scheme. The present study describes, for the first time in Brazil, the close follow-up of a series of patients using a raltegravir-containing HAART, showing the safety of the enfuvirtide switch to RAL and the effectiveness of a therapeutic regimen with RAL in promoting immune reconstitution and suppressing HIV replication, as well as documenting the occurrence of resistance to integrase inhibitors in the country.

Switching virally suppressed, treatment-experienced patients to a raltegravir-containing regimen does not alter levels of HIV-1 DNA

BACKGROUND

Current HIV-1 antiretroviral therapy (ART) greatly reduces virus replication but does not significantly affect the viral reservoir. Raltegravir, a recently introduced integrase inhibitor, could, at least theoretically, reduce residual viremia in patients on ART and affect the viral reservoir size. The aim of this study was to assess whether switching therapy in treatment-experienced patients that were virally suppressed to a raltegravir-containing regimen reduces the size of the viral reservoir, and if such treatment leads to a change in levels of HIV 2-LTR circles in this patient group.

METHODS

14 ART experienced individuals with a suppressed viral load (<50 HIV-1 RNA copies/mL plasma) at baseline (for at least 2 months) were switched to a raltegravir-containing regimen. Blood samples were taken at baseline and at ≥2 timepoints up to 48±6 weeks. Levels of total HIV-1 DNA and 2-LTR circles in peripheral blood mononuclear cells (PBMCs) were measured using real-time PCR assays.

RESULTS

There was no significant change in HIV-1 total DNA levels over the study duration (p = 0.808), median slope 0.24 (conservative nonparametric 95% CI: -11.78, 26.23). Low levels of 2-LTR circles were detected in 2 patients. One had 16 copies/10(6) PBMCs at baseline and the other had 34 copies/10(6) PBMCs at week 51.

CONCLUSIONS

The switch to a raltegravir containing regimen was not associated with a significant change in HIV-1 total DNA levels in this cohort. There were no observed changes in the levels of HIV-1 2-LTR circles associated with raltegravir treatment initiation.

Authentic HIV-1 integrase inhibitors

HIV-1 integrase (IN) is indispensable for HIV-1 replication and has become a validated target for developing anti-AIDS agents. In two decades of development of IN inhibition-based anti-HIV therapeutics, a significant number of compounds were identified as IN inhibitors, but only some of them showed antiviral activity. This article reviews a number of patented HIV-1 IN inhibitors, especially those that possess high selectivity for the strand transfer reaction. These compounds generally have a polar coplanar moiety, which is assumed to chelate two magnesium ions in the binding site. Resistance to those compounds, when given to patients, can develop as a result of IN mutations. We refer to those compounds as authentic IN inhibitors. Continued drug development has so far delivered one authentic IN inhibitor to the market (raltegravir in 2007). Current and future attention will be focused on the development of novel authentic IN inhibitors with the goal of overcoming viral resistance.

Efficacy and safety of raltegravir in treatment-experienced HIV-1-infected patients switching from enfuvirtide-based regimens: 48 week results of the randomized EASIER ANRS 138 trial

OBJECTIVES

To assess the sustainable efficacy and safety of a switch from enfuvirtide to raltegravir in patients with multidrug-resistant HIV infection.

METHODS

One hundred and seventy patients with multidrug-resistant HIV infection and suppressed plasma HIV RNA levels < 400 copies/mL under an enfuvirtide-based regimen were randomized to maintain their regimen or to switch to a raltegravir-based regimen (immediate group) in a 48 week prospective, randomized, open-label trial. At week 24, patients in the maintenance arm also switched to raltegravir (deferred group). Baseline genotypic susceptibility scores (GSSs) were calculated using available historical resistance tests. Efficacy was assessed by the cumulative proportion of patients with virological failure, defined as a confirmed plasma HIV RNA ≥ 400 copies/mL up to week 48. The EASIER ANRS 138 trial is registered at ClinicalTrials.gov (NCT00454337).

RESULTS

At baseline, 86% of patients had plasma HIV RNA levels <50 copies/mL and 86% had a GSS ≥ 1. Through to week 48, in the on-treatment analysis, only one patient in the immediate group, with a GSS of 0, developed virological failure. At week 48, 90% of patients in both the immediate and deferred groups had plasma HIV-1 RNA levels <50 copies/mL. Median CD4 cell counts remained stable during follow-up. Of note, 12 of 66 (18.2%) patients receiving a regimen combining raltegravir and ritonavir-boosted tipranavir experienced alanine aminotransferase elevations, which led to a switch from tipranavir to darunavir in 8 cases, without discontinuation of raltegravir.

CONCLUSIONS

In well-suppressed patients with multidrug-resistant HIV infection, a switch from enfuvirtide to raltegravir is generally well tolerated and has sustained antiviral efficacy when combined with a potent background regimen.

Biomarkers of HIV replication

PURPOSE OF REVIEW

Viremia provides a biomarker for HIV-1 replication in various tissues. The purpose of this review is to discuss the relationship between viremia and viral replication at a theoretical level and to review recent advances in understanding this relationship, particularly in the context of highly active antiretroviral therapy (HAART).

RECENT FINDINGS

Recent studies have focused on understanding the extremely low level of residual viremia that can be detected in patients on HAART. The two major explanations for this residual viremia are that it represents ongoing cycles of replication that continue despite HAART or that it represents release of virus from stable reservoirs. The recent finding that intensification of HAART does not further reduce residual viremia supports that latter hypothesis. Direct sequence analysis of the residual viremia has provided new insights into the complex relationship between residual viremia and viral reservoirs.

SUMMARY

In patients with untreated HIV-1 infection, the level of viremia is a direct indication of the level of viral replication and a predictor of the rate of CD4 depletion. However, when viral replication is suppressed by HAART, the level of residual viremia is to a large extent an indication of virus release from stable viral reservoirs.

Impact on health-related quality of life of a switch from enfuvirtide to raltegravir among multidrug-resistant HIV-1-infected patients: a randomized open-label trial (EASIER-ANRS 138)

BACKGROUND

among multidrug-resistant HIV-1-infected patients, enfuvirtide has demonstrated sustained efficacy, but long-term use is inconvenient due to twice-daily subcutaneous injections which often induce injection-site reactions. We investigated whether a switch from enfuvirtide to raltegravir, an orally available HIV-integrase inhibitor, may improve health-related quality of life (HRQoL).

METHODS

170 multidrug-resistant HIV-1-infected patients who were receiving enfuvirtide-based regimens were randomised to the maintenance of enfuvirtide or the switch to raltegravir at day 0. At week 24, all patients received raltegravir up to week 48. HRQoL was assessed at baseline and weeks 24 and 48 using a self-report MOS-HIV questionnaire. HRQoL scores were compared between arms using analysis of covariance (ANCOVA) models.

RESULTS

at week 24, least-squares means changes from baseline for the maintenance and the substitution arms were -5.3 and +5.8 (P = .001) for the pain score, -4.7 and +4.8 (P = .02) for the social functioning score, and -1.3 and +2.0 (P = .003) for the physical summary score, respectively.

CONCLUSION

among multidrug-resistant HIV-1-infected patients, a switch from enfuvirtide to raltegravir resulted in statistically significant improvements in multiple HRQoL dimensions over 24 weeks in comparison to the maintenance under enfuvirtide.

Treatment simplification in HIV-infected adults as a strategy to prevent toxicity, improve adherence, quality of life and decrease healthcare costs

Since the advent of highly active antiretroviral therapy (HAART), the treatment of human immunodeficiency virus (HIV) infection has become more potent and better tolerated. While the current treatment regimens still have limitations, they are more effective, more convenient, and less toxic than regimens used in the early HAART era, and new agents, formulations and strategies continue to be developed. Simplification of therapy is an option for many patients currently being treated with antiretroviral therapy (ART). The main goals are to reduce pill burden, improve quality of life and enhance medication adherence, while minimizing short- and long-term toxicities, reducing the risk of virologic failure and maximizing cost-effectiveness. ART simplification strategies that are currently used or are under study include the use of once-daily regimens, less toxic drugs, fixed-dose coformulations and induction-maintenance approaches. Improved adherence and persistence have been observed with the adoption of some of these strategies. The role of regimen simplification has implications not only for individual patients, but also for health care policy. With increased interest in ART regimen simplification, it is critical to study not only implications for individual tolerability, toxicity, adherence, persistence and virologic efficacy, but also cost, scalability, and potential for dissemination and implementation, such that limited human and financial resources are optimally allocated for maximal efficiency, coverage and sustainability of global HIV/AIDS treatment.

A 48-week pilot study switching suppressed patients to darunavir/ritonavir and etravirine from enfuvirtide, protease inhibitor(s), and non-nucleoside reverse transcriptase inhibitor(s)

Treatment options for HIV-infected patients can be limited due to viral drug resistance to antiretroviral agents. Enfuvirtide (ENF) is an injectable entry/fusion inhibitor that is effective in achieving viral suppression when used in combination with protease inhibitors (PIs) in patients with pre-existing resistance. However, ENF treatment is associated with injection site reactions and dosing fatigue. This multicenter, open-label, Phase IIIb, 48-week pilot study assessed safety, tolerability, and effectiveness of the PI darunavir (DRV), boosted with ritonavir (DRV/r), and the non-nucleoside reverse transcriptase inhibitor (NNRTI) etravirine (ETR), when substituted for ENF/PI (±NNRTI)-based therapy. Ten virologically suppressed (HIV RNA less than 50 copies/ml) men who were intolerant to ENF were enrolled. Median (range) CD4+ count was 301 (187-663) cells/mm(3). Two patients discontinued the study; all remaining patients maintained a viral load of less than 50 copies/ml at Week 48. Viral load increased to greater than 50 copies/ml in two patients, but was eventually re-suppressed without the need for changes in treatment. Median (range) increase (last observation carried forward) in CD4+ count from baseline to Week 48 was 64 (-53-100) cells/mm(3). Two grade 3 adverse events (AEs), nausea and weight loss, and one serious AE, acute cholecystitis, were reported; each AE resolved without treatment interruption. Most common AEs related to study drug were fatigue, rash, headache, and diarrhea. Decreases in triglycerides, low-density lipoprotein, and high-density lipoprotein, were observed. This study suggests that a DRV/r- and ETR-based regimen can be substituted for an ENF-based regimen while maintaining virologic suppression.

Time course of total HIV-1 DNA and 2-long-terminal repeat circles in patients with controlled plasma viremia switching to a raltegravir-containing regimen

BACKGROUND

Early integration of HIV proviral DNA into the host cell genome prevents viral eradication, despite suppressive HAART. In vitro, integrase inhibitors reduce proviral DNA levels and rapidly increase 2-long-terminal repeat (LTR) circle levels. We examined the effect of raltegravir on the time course of HIV-1 DNA forms in patients with controlled viremia.

PATIENTS AND METHODS

The EASIER-ANRS 138 randomized trial demonstrated that switching from enfuvirtide to raltegravir maintained virological suppression in treatment-experienced patients with viral load below 400 copies/ml. We analyzed total HIV-1 DNA and 2-LTR circle levels measured at weeks (W)0 and 24 in the first 30 patients enrolled in each arm, and at W48 in the raltegravir arm.

RESULTS

At W0 the total DNA level was 3.6 log(10)/10(6) peripheral blood mononuclear cell (PBMC) in both groups, and 2-LTR circles were detected in six patients (median 89 copies/10(6) PBMC). At W24 the total DNA level was 3.6 log(10)/10(6) PBMC in both groups, and 2-LTR circles were detected in three new patients. At W48 the total HIV DNA level in the raltegravir group was 3.5 log(10)/10(6) PBMC, and 2-LTR circles were undetectable. No significant change in total HIV DNA occurred between W0 and W24 in either arm (P = 0.71) and no significant change was observed in the raltegravir arm at W48.

DISCUSSION

In most patients on effective HAART, including regimens containing an integrase inhibitor, the viral reservoir, reflected by the HIV-1 DNA load, is stable and nondynamic during the 48 weeks of follow-up.

Clinical, virological and immunological responses in Danish HIV patients receiving raltegravir as part of a salvage regimen

BACKGROUND

Raltegravir is the first integrase inhibitor approved for treatment of HIV-infected patients harboring multiresistant viruses.

METHODS

From a Danish population-based nationwide cohort of HIV patients we identified the individuals who initiated a salvage regimen including raltegravir and a matched cohort of HIV-infected patients initiating HAART for the first time. We compared these two cohorts for virological suppression, gain in CD4 count, and time to first change of initial regimen.

RESULTS

We identified 32 raltegravir patients and 64 HIV patients who initiated HAART for the first time in the period 1 January 2006 to 1 July 2009. The virological and immunological responses in the raltegravir patients were comparable to those seen in the control cohort. No patients in the two cohorts died and no patients terminated raltegravir treatment in the observation period. Time to first change of initial regimen was considerably shorter for HAART-naïve patients.

CONCLUSION

We conclude that salvage regimens including raltegravir have high effectiveness in the everyday clinical setting. The effectiveness of the regimens is comparable to that observed for patients initiating HAART for the first time. The risk of change in the salvage regimens after initiation of raltegravir is low.