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

Efficacy and Safety of Raltegravir-Based Dual Therapy in AIDS Patients: A Meta-Analysis of Randomized Controlled Trials

Background: The life expectancy for HIV-infected individuals has improved dramatically because of improvements in antiretroviral therapy (ART). Today, a simplified two-drug regimen enhances adherence and treatment satisfaction by reducing adverse effects. Therefore, we need more evidence to show the benefits and risks of simplified ART regimens from randomized controlled trials (RCTs). We compared the efficacy and safety of raltegravir-based simplified dual therapy (DT) and of traditional triple therapy (TT) for people living with HIV/AIDS (PLWHA). Methods: We carried out a systematic review of RCTs. After using a combination of the key words "HIV," "raltegravir," and "protease inhibitor" to search the English-language electronic databases from January 1, 2004, to September 11, 2019, we pooled data across eligible studies and estimated the summary effect sizes with Review Manager (version 5.3). Results: We included eight RCTs involving 4420 PLWHA: 2187 (49.5%) received raltegravir-based simplified DT, and 2144 (48.5%) received traditional TT. The proportion of viral suppression was 79% at 48 weeks and 74% at 96 weeks in the simplified regimen, and the proportion of viral suppression was 78% at 48 weeks and 71% at 96 weeks in the traditional TT group. Furthermore, the proportion of viral suppression in the simplified DT group was greater than that in the TT group at 24 weeks (risk ratio 1.11, 95% confidence interval 1.02-1.21; p = 0.01). The CD4 cell counts in the simplified DT group were significantly higher at 48 weeks and 96 weeks than those in the group that received the traditional TT. Regarding adverse events and mortality rates, the DT and TT groups were similar. However, there was better adherence in the DT group than in the TT group. Conclusion: We found that the simplified regimen was noninferior to TT regimen in regard to viral suppression. Furthermore, the simplified DT regimen had a better CD4 cell count and lower adverse events than the TT regimen.

Metabolic, mitochondrial, renal and hepatic safety of enfuvirtide and raltegravir antiretroviral administration: Randomized crossover clinical trial in healthy volunteers

CONTEXT

Classical antiretroviral agents may acutely impact on metabolic, mitochondrial, renal and hepatic function in HIV-infected and uninfected persons. Fusion and integrase inhibitors are supposed to be safer, but have been scarcely investigated. To avoid any interference with HIV or other antiretrovirals, we assessed markers of these toxicities in healthy adult volunteers treated with Enfuvirtide (T20) or Raltegravir (RAL).

METHODS

Twenty-six healthy participants were randomized to T20/90mg vs. placebo (n = 12) or RAL/400mg vs. placebo (n = 14) every 12h in two 7-day periods separated by a 4-week washout period. Major end-points were changes in lipid profile (total cholesterol, high-density-lipoprotein (HDL)-cholesterol, low-density-lipoprotein (LDL)-cholesterol, triglycerides), insulin resistance (glucose) and mitochondrial toxicity (mitochondrial DNA content-mtDNA-in peripheral blood mononuclear cells). Renal and hepatic toxicity (creatinine, alanine transaminase (AST), alanine aminotransferase (ALT), bilirubin and total plasma proteins) and overall safety were also analysed. Effect of period, treatment, and basal measures were evaluated for each end-point.

RESULTS

Neither T20-administration nor RAL-administration yielded to any statistic significant change in the markers of metabolic, mitochondrial, renal or hepatic toxicity assessed. No symptoms indicative of drug toxicity were neither found in any subject.

CONCLUSIONS

In absence of HIV infection, or concomitant treatment, short-term exposure to T20 or RAL in healthy adult volunteers did not lead to any indicative changes in toxicity markers thus presuming the safe profile of both drugs.

Integrase Inhibitors: After 10 Years of Experience, Is the Best Yet to Come?

The era of the integrase strand transfer inhibitors (INSTIs) for the treatment of human immunodeficiency virus (HIV) infection began with raltegravir in 2007. Since that time, several other INSTIs have been introduced including elvitegravir, dolutegravir, and, most recently, bictegravir, that have shown great utility as part of antiretroviral regimens in both treatment-naive and treatment-experienced patients. At present, antiretroviral guidelines fully endorse the INSTI class as part of all first-line treatment regimens. After 10 years of experience with INSTIs, newer agents are on the horizon such as cabotegravir and MK-2048 for potential use as either HIV pre-exposure prophylaxis or maintenance therapy. This review provides a brief overview of the INSTI class including agents currently available and those still in development, reviews available data from both completed and ongoing clinical trials, and outlines simplification strategies using INSTIs.

Efficacy and Safety of Raltegravir-Based Dual Therapy in AIDS Patients: A Meta-Analysis of Randomized Controlled Trials

Background: The life expectancy for HIV-infected individuals has improved dramatically because of improvements in antiretroviral therapy (ART). Today, a simplified two-drug regimen enhances adherence and treatment satisfaction by reducing adverse effects. Therefore, we need more evidence to show the benefits and risks of simplified ART regimens from randomized controlled trials (RCTs). We compared the efficacy and safety of raltegravir-based simplified dual therapy (DT) and of traditional triple therapy (TT) for people living with HIV/AIDS (PLWHA). Methods: We carried out a systematic review of RCTs. After using a combination of the key words "HIV," "raltegravir," and "protease inhibitor" to search the English-language electronic databases from January 1, 2004, to September 11, 2019, we pooled data across eligible studies and estimated the summary effect sizes with Review Manager (version 5.3). Results: We included eight RCTs involving 4420 PLWHA: 2187 (49.5%) received raltegravir-based simplified DT, and 2144 (48.5%) received traditional TT. The proportion of viral suppression was 79% at 48 weeks and 74% at 96 weeks in the simplified regimen, and the proportion of viral suppression was 78% at 48 weeks and 71% at 96 weeks in the traditional TT group. Furthermore, the proportion of viral suppression in the simplified DT group was greater than that in the TT group at 24 weeks (risk ratio 1.11, 95% confidence interval 1.02-1.21; p = 0.01). The CD4 cell counts in the simplified DT group were significantly higher at 48 weeks and 96 weeks than those in the group that received the traditional TT. Regarding adverse events and mortality rates, the DT and TT groups were similar. However, there was better adherence in the DT group than in the TT group. Conclusion: We found that the simplified regimen was noninferior to TT regimen in regard to viral suppression. Furthermore, the simplified DT regimen had a better CD4 cell count and lower adverse events than the TT regimen.

Similar long-term efficacy of dual therapy containing raltegravir and a boosted protease inhibitor versus standard triple therapies in pretreated HIV-1-infected patients in a retrospective, real-life cohort of 14 years

OBJECTIVES

Raltegravir is used in many antiretroviral combinations, but its use in treatment-experienced patients without knowledge of baseline resistance is discussed controversially as a number of comparative studies have shown a higher rate of virological failure. However, it has been used frequently for the management of treatment failure, as it was the first integrase inhibitor to become available, and thus offered new options for patients with multiple resistance. The strategic use of raltegravir in this setting is examined in this study.

METHODS

In order to examine the efficacy of raltegravir in second and later lines of antiretroviral combinations, data for 740 patients from three clinical cohorts were analysed with a focus on the combinations that were used. These were stratified into the combination of two nonnucleoside reverse transcriptase inhibitors and raltegravir (2NRTIs + RAL), the combination of a boosted protease inhibitor and raltegravir (bPI + RAL), and other raltegravir-containing combinations.

RESULTS

The overall rate of virological suppression to < 50 HIV-1 RNA copies/mL was 69.5%. Although the baseline rate of virological suppression was higher for 2NRTIs + RAL than for the other strata, the outcomes were similar for all three groups at weeks 24, 48, 72 and 96.

CONCLUSIONS

These data indicate that, in a real-life setting, raltegravir can be used with a high virological success rate in treatment-experienced patients, and that the different combinations analysed (2NRTIs + RAL, bPI + RAL and others) show comparable rates of virological suppression.

The treatment outcomes of antiretroviral substitutions in routine clinical settings in Asia; data from the TREAT Asia HIV Observational Database (TAHOD)

Introduction

Although substitutions of antiretroviral regimen are generally safe, most data on substitutions are based on results from clinical trials. The objective of this study was to evaluate the treatment outcomes of substituting antiretroviral regimen in virologically suppressed HIV‐infected patients in non‐clinical trial settings in Asian countries.

Methods

The study population consisted of HIV‐infected patients enrolled in the TREAT Asia HIV Observational Database (TAHOD). Individuals were included in this analysis if they started combination antiretroviral treatment (cART) after 2002, were being treated at a centre that documented a median rate of viral load monitoring ≥0.8 tests/patient/year among TAHOD enrolees, and experienced a minor or major treatment substitution while on virally suppressive cART. The primary endpoint to evaluate outcomes was clinical or virological failure (VF), followed by an ART class change. Clinical failure was defined as death or an AIDS diagnosis. VF was defined as confirmed viral load measurements ≥400 copies/mL followed by an ART class change within six months. Minor regimen substitutions were defined as within‐class changes and major regimen substitutions were defined as changes to a drug class. The patterns of substitutions and rate of clinical or VF after substitutions were analyzed.

Results

Of 3994 adults who started ART after 2002, 3119 (78.1%) had at least one period of virological suppression. Among these, 1170 (37.5%) underwent a minor regimen substitution, and 296 (9.5%) underwent a major regimen substitution during suppression. The rates of clinical or VF were 1.48/100 person years (95% CI 1.14 to 1.91) in the minor substitution group, 2.85/100 person years (95% CI 1.88 to 4.33) in the major substitution group and 2.53/100 person years (95% CI 2.20 to 2.92) among patients that did not undergo a treatment substitution.

Conclusions

The rate of clinical or VF was low in both major and minor substitution groups, showing that regimen substitution is generally effective in non‐clinical trial settings in Asian countries.

Incidence of cancer and overall risk of mortality in individuals treated with raltegravir-based and non-raltegravir-based combination antiretroviral therapy regimens

Objectives

There are currently few data on the long‐term risk of cancer and death in individuals taking raltegravir (RAL). The aim of this analysis was to evaluate whether there is evidence for an association.

Methods

The EuroSIDA cohort was divided into three groups: those starting RAL‐based combination antiretroviral therapy (cART) on or after 21 December 2007 (RAL); a historical cohort (HIST) of individuals adding a new antiretroviral (ARV) drug (not RAL) to their cART between 1 January 2005 and 20 December 2007, and a concurrent cohort (CONC) of individuals adding a new ARV drug (not RAL) to their cART on or after 21 December 2007. Baseline characteristics were compared using logistic regression. The incidences of newly diagnosed malignancies and death were compared using Poisson regression.

Results

The RAL cohort included 1470 individuals [with 4058 person‐years of follow‐up (PYFU)] compared with 3787 (4472 PYFU) and 4467 (10 691 PYFU) in the HIST and CONC cohorts, respectively. The prevalence of non‐AIDS‐related malignancies prior to baseline tended to be higher in the RAL cohort vs. the HIST cohort [adjusted odds ratio (aOR) 1.31; 95% confidence interval (CI) 0.95–1.80] and vs. the CONC cohort (aOR 1.89; 95% CI 1.37–2.61). In intention‐to‐treat (ITT) analysis (events: RAL, 50; HIST, 45; CONC, 127), the incidence of all new malignancies was 1.11 (95% CI 0.84–1.46) per 100 PYFU in the RAL cohort vs. 1.20 (95% CI 0.90–1.61) and 0.83 (95% CI 0.70–0.99) in the HIST and CONC cohorts, respectively. After adjustment, there was no evidence for a difference in the risk of malignancies [adjusted rate ratio (RR) 0.73; 95% CI 0.47–1.14 for RALvs. HIST; RR 0.95; 95% CI 0.65–1.39 for RALvs. CONC] or mortality (adjusted RR 0.87; 95% CI 0.53–1.43 for RALvs. HIST; RR 1.14; 95% CI 0.76–1.72 for RALvs. CONC).

Conclusions

We found no evidence for an oncogenic risk or poorer survival associated with using RAL compared with control groups.

Cardiovascular risk and dyslipidemia among persons living with HIV: a review

BACKGROUND

Aim of this review is to focus the attention on people living with HIV infection at risk of developing a cardiovascular event. What is or what would be the most suitable antiretroviral therapy? Which statin or fibrate to reduce the risk? How to influence behavior and lifestyles?

DISCUSSION

Prevention of cardiovascular disease (CVD) risk remains the first and essential step in a medical intervention on these patients. The lifestyle modification, including smoking cessation, increased physical activity, weight reduction, and the education on healthy dietary practices are the main instruments. Statins are the cornerstone for the treatment of hypercholesterolemia. They have been shown to slow the progression or promote regression of coronary plaque, and could also exert an anti-inflammatory and immunomodulatory effect. However the current guidelines for the use of these drugs in general population are dissimilar, with important differences between American and European ones. The debate between American and European guidelines is still open and, also considering the independent risk factor represented by HIV, specific guidelines are warranted. Ezetimibe reduces the intestinal absorption of cholesterol. It is effective alone or in combination with rosuvastatin. It does not modify plasmatic concentrations of antiretrovirals. A number of experimental new classes of drugs for the treatment of hypercholesterolemia are being studied. Fibrates represent the first choice for treatment of hypertriglyceridemia, however, the renal toxicity of fibrates and statins should be considered. Omega 3 fatty acids have a good safety profile, but their efficacy is limited. Another concern is the high dose needed. Other drugs are acipimox and tesamorelin. Current antiretroviral therapies are less toxic and more effective than regimens used in the early years. Lipodistrophy and dyslipidemia are the main causes of long-term toxicities. Not all antiretrovirals have similar toxicities. Protease Inhibitors may cause dyslipidemia and lipodystrophy, while integrase inhibitors have a minimal impact on lipids profile, and no evidence of lipodystrophy. There is still much to be written with the introduction of new drugs in clinical practice.

CONCLUSIONS

Cardiovascular risk among HIV infected patients, interventions on behavior and lifestyles, use of drugs to reduce the risk, and switch in antiretroviral therapy, remain nowadays major issues in the management of HIV-infected patients.

Effectiveness and Risk Factors for Virological Outcome of Raltegravir-Based Therapy for Treatment-Experienced HIV-Infected Patients

Objective

We evaluated the effectiveness of a raltegravir (RAL)-containing regimen plus an optimized background regimen in HIV-1 highly treatment-experienced patients.

Design

A retrospective cohort, multicentre study was conducted.

Methods

Adult (>16 years old) HIV treatment-experience patients starting therapy with a RAL-containing regimen were included. Effectiveness was evaluated as the percentage of patients with an undetectable HIV-1 RNA viral load (<50 and <200 copies/mL) after 48 weeks, and changes in CD4+ cell counts. We evaluated the risk factors associated with treatment failure.

Results

Of the 107 patients in the cohort, 86% were men, the median age was 45 years [interquartile range (IQR) 40–52] and the median number of previous regimens was six (IQR 4–7). After 48 weeks of treatment, 73% (IQR 63–80%) of patients (n = 78) had a viral load of <50 copies/mL and 85% (IQR 77–90%) (n = 91) had <200 copies/mL. In a logistic regression model, risk factors associated with a virological outcome of HIV-1 RNA of <200 copies/mL were age >40 years [odds ratio (OR) 5.61; 95% confidence interval (CI) 1.61–18.84; P = 0.006] and use of tenofovir in the regimen (OR 0.16; 95% CI 0.03–0.80; P = 0.026).

Conclusions

In this Mexican cohort, RAL achieved high rates of virological suppression and an increase in CD4+ cell count in highly treatment-experienced patients infected with HIV-1. Age >40 years was associated with a good virological outcome, contrary to tenofovir use, which was associated with a poor virological outcome.

Continuous intravenous infusion of enfuvirtide in a patient with a multidrug-resistant HIV strain

Case description To evaluate whether continuous intravenous (i.v.) administration of enfuvirtide (T20) could be a suitable alternative to subcutaneous (s.c.) administration of T20 in a patient with extensively drug-resistant HIV experiencing difficulties administering T20 subcutaneously. T20 was administered to a patient through 100 mL cassettes once daily via a CADD. Plasma samples were drawn and the pharmacokinetic profile compared to that of s.c. twice daily administration of T20. Also, viral replication and CD4+ count were monitored over a period of 9 months for this study. Continuous i.v. administration of T20 resulted in significantly higher T20 plasma levels compared to s.c. administration, continued viral suppression, a rise in CD4+ count and strong patient preference over s.c. administration. Conclusion This method of T20 administration may be a suitable alternative for selected patients who are not able to tolerate it when given subcutaneously. It may even be considered a priori in selected patients with extensive viral resistance who are unable or unwilling to inject T20 subcutaneously.

Incidence and risk factors for liver enzymes elevations in highly treatment-experienced patients switching from enfuvirtide to raltegravir: a sub-study of the ANRS-138 EASIER trial

Background

In the ANRS EASIER trial where treatment-experienced patients switched from enfuvirtide (ENF) to raltegravir (RAL), a high incidence of transaminase elevation was reported in the RAL arm.

Methods

We compared the incidence of emergent liver enzyme elevations (LEE) of grade 2 or more among patients randomized to the maintenance ENF arm or the switch RAL arm up to W24. We also assessed the overall incidence of LEE over the 48-week duration of the trial and baseline risk factors for grade 2 or more alanine aminotransferase (ALT) elevation using univariate and multivariate analyses.

Results

During the first 24 weeks, 6/84 (7.1 %) and 2/85 patients (2.4 %) presented with ALT elevation of grade 2 or more in the RAL and ENF arms, respectively (p = 0.21). Grade 2 or more γGT and ALP elevations were seen in 18 and 11 % (p = 0.35), and 5 and 1 % (p = 0.14) of patients in the RAL and ENF arms, respectively. The 48-week incidence of grade 2 or more LEE was 11.6 per 100-pts-years for ALT, 24.5 per 100-pts-years for γ-GT and 4.5 per 100-pts-years for ALP, respectively. In the multivariate analysis, tipranavir/ritonavir use (OR 3.66; 95 % CI [1.20–11.1], p = 0.022) and elevated ALT at baseline (OR 10.3; 95 % CI [2.67–39.6], p < 10⁻³) were significantly associated with a grade 2 or more ALT elevation during follow-up.

Conclusion

The incidence of LEE was relatively high in these highly treatment-experienced patients switching to a RAL-based regimen. Both tipranavir/ritonavir use and high baseline ALT levels were associated with an increased risk of ALT.

Trial registration: ClinicalTrials.gov identifier: NCT00454337

Review of integrase strand transfer inhibitors for the treatment of human immunodeficiency virus infection

Integrase strand transfer inhibitors (INSTIs) are oral antiretroviral agents used against HIV infection. There are three agents available, including raltegravir, elvitegravir and dolutegravir, some of which are available as combination medications with other antiretroviral drugs. The efficacy and safety of INSTIs in treatment-naïve and experienced HIV-infected patients have been established by multiple studies. Based on the current practice guidelines, INSTI-based regimens are considered as one of the first-line therapies for treatment-naïve HIV-infected patients. There are new INSTIs in development to improve the resistance profile and to decrease the frequency of drug administration.

Skeletal muscle toxicity in HIV-1-infected patients treated with a raltegravir-containing antiretroviral therapy: a cohort study

To evaluate the frequency of myopathy and serum creatine kinase (CK) elevation associated with the use of the integrase inhibitor raltegravir we conducted a retrospective, cohort analysis assessing the incidence of skeletal muscle toxicity among HIV-infected patients treated with raltegravir. Adult HIV-infected patients who started a raltegravir-containing therapy were enrolled into the study. The skeletal muscle toxicity was defined by the presence of one or more of the following parameters: (1) isolated and significant CK elevation without signs or symptoms; (2) diffuse myalgia without weakness; (3) proximal muscle weakness; (4) rhabdomyolysis. On the whole, 155 patients were included in the study, with a mean age of 49.2 years; the median duration of the raltegravir treatment was 30.7 months. The overall frequency of skeletal muscle toxicity was 23.9%, with an incidence of 4.7/100 person-years. An isolated CK elevation was reported in 21.3% of cases, while less than 3% of patients complained of myalgia or muscle weakness. The CK elevation was usually of grade 1 or 2 and self-limiting, and laboratory or clinical abnormalities did not require discontinuation of raltegravir in any patient. Factors significantly associated with skeletal muscle toxicity were previous use of zidovudine, higher baseline CK levels, previous increase of the CK levels, and a higher body mass index. Skeletal muscle toxicity is not an unusual adverse event in subjects receiving raltegravir, but it is usually represented by a mild-to-moderate increase in CK concentration, while clinical symptoms of myopathy are very uncommon.

Long-term efficacy and safety of raltegravir in the management of HIV infection

Raltegravir is an integrase strand-transfer inhibitor approved for the treatment of HIV infection. It was the first medication in a novel class of antiretroviral agents to be approved for use in the United States in 2007. Raltegravir exhibits potent activity against wild-type HIV-1, but resistance development has been noted through three different pathways. It is metabolized primarily through uridine diphosphate glucuronosyltransferase 1A1 and has a single inactive glucuronide metabolite. Raltegravir is not a substrate, inhibitor, or inducer of cytochrome P450 enzymes and exhibits low potential for drug–drug interactions; however, strong uridine diphosphate glucuronosyltransferase 1A1 inhibitors or inducers can alter the pharmacokinetics of raltegravir. It is well tolerated, and the most commonly reported adverse effects include headache, nausea, and diarrhea. Serious adverse effects with raltegravir are rare but include rhabdomyolysis and severe skin and hypersensitivity reactions. It has been approved for use in both treatment-naïve and treatment-experienced patients and is a preferred first-line agent in both United States and European HIV treatment guidelines. Although initial approval was granted on 48-week data, 5-year clinical data have recently been published. This article reviews the data supporting long-term efficacy and safety of raltegravir in the treatment of HIV infection.

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.

Virologic and Immunologic Effectiveness at 48 Weeks of Darunavir–Ritonavir-Based Regimens in Treatment-Experienced Persons Living with HIV-1 Infection in Clinical Practice

Introduction:

Published data addressing the effectiveness of darunavir–ritonavir (DRV/r)-based therapy for multiexperienced patients in developing countries are scarce. This study evaluated the 48-week virologic and immunologic effectiveness of salvage therapy based on DRV/r for the treatment of multidrug-experienced HIV-1-infected adults in Brazil.

Materials and Methods:

A multicenter retrospective cohort study was carried out with multidrug-experienced adults who were on a failing antiretroviral therapy and started a DRV/r-based salvage therapy between 2008 and 2010. The primary effectiveness end point was the proportion of patients with virologic success (plasma HIV-1 RNA <50 copies/mL at week 48).

Results:

At 48 weeks, 73% of the patients had HIV-RNA <50 copies/mL and a mean increase of 108 CD4 cells/mm3. Higher baseline viral load, lower baseline CD4 count, younger age, and 3 or more DRV/r-associated resistance mutations were significantly predictive of virologic failure. Concomitant use of raltegravir was strongly associated with virologic success.

Conclusion:

The use of DRV/r-based regimens for salvage therapy is an effective strategy in the clinical care setting of a developing country.

Decreases in inflammatory and coagulation biomarkers levels in HIV-infected patients switching from enfuvirtide to raltegravir: ANRS 138 substudy

Stored plasma specimens from 164 participants in the ANRS 138 trial were analyzed to determine interleukin 6 (IL-6), high-sensitivity C-reactive protein (hsCRP), and D-dimer levels at baseline and weeks 24 and 48. These virologically suppressed, treatment-experienced patients were randomly assigned to undergo an immediate switch (IS) or a deferred switch (DS; at week 24) from an enfuvirtide-based antiretroviral therapy (ART) regimen to a raltegravir-based regimen. At week 24, a significant decrease from baseline was observed in the IS arm, compared with the DS arm, for IL-6 level (-30% vs +10%; P < .002), hsCRP level (-46% vs +15%; P < .0001), and D-dimer level (-40% vs +6%; P < .0001). At week 48, there was a reproducible decrease in levels of all biomarkers in the DS arm.

Emerging patterns and implications of HIV-1 integrase inhibitor resistance

PURPOSE OF REVIEW

This review highlights recent data on the pathways of resistance that impact the clinical activity of first-generation and second-generation integrase inhibitors.

RECENT FINDINGS

Raltegravir (RAL) and elvitegravir (EVG) are highly efficacious in first-line antiretroviral therapy, with small numbers of virological failures observed in clinical trials. Durable activity in treatment-experienced patients requires a fully supportive background regimen. RAL and EVG show a low-to-moderate genetic barrier to resistance and extensive cross-resistance, which preclude their sequential use. Resistance to dolutegravir (DTG) is not selected as readily in vitro and has not emerged in studies of treatment-naïve patients to date. Both in vitro and in vivo, DTG retains activity against several RAL and EVG resistant strains, but susceptibility is variably impaired by multiple mutations within the G148 pathway, which are common after RAL or EVG failure. Cross-resistance can be partially overcome by doubling DTG dosing to twice daily, but durability of responses remains dependent on a supportive background regimen. There is variability in the integrase gene of circulating HIV strains, which does not appear to reduce drug activity, although it may influence the emergence and evolution of integrase resistance. Transmission of integrase resistance remains rare but surveillance is required.

SUMMARY

Integrase inhibitors provide a potent option for the treatment of HIV infection. Drug resistance remains a challenge, which may be partially overcome by the introduction of second-generation compounds. Prompt management of RAL and EVG failure is required to prevent the accumulation of multiple resistance mutations that reduce DTG susceptibility.

Clinical use of HIV integrase inhibitors: a systematic review and meta-analysis

Background

Optimal regimen choice of antiretroviral therapy is essential to achieve long-term clinical success. Integrase inhibitors have swiftly been adopted as part of current antiretroviral regimens. The purpose of this study was to review the evidence for integrase inhibitor use in clinical settings.

Methods

MEDLINE and Web-of-Science were screened from April 2006 until November 2012, as were hand-searched scientific meeting proceedings. Multiple reviewers independently screened 1323 citations in duplicate to identify randomized controlled trials, nonrandomized controlled trials and cohort studies on integrase inhibitor use in clinical practice. Independent, duplicate data extraction and quality assessment were conducted.

Results

48 unique studies were included on the use of integrase inhibitors in antiretroviral therapy-naive patients and treatment-experienced patients with either virological failure or switching to integrase inhibitors while virologically suppressed. On the selected studies with comparable outcome measures and indication (n = 16), a meta-analysis was performed based on modified intention-to-treat (mITT), on-treatment (OT) and as-treated (AT) virological outcome data. In therapy-naive patients, favorable odds ratios (OR) for integrase inhibitor-based regimens were observed, (mITT OR 0.71, 95% CI 0.59–0.86). However, integrase inhibitors combined with protease inhibitors only did not result in a significant better virological outcome. Evidence further supported integrase inhibitor use following virological failure (mITT OR 0.27; 95% CI 0.11–0.66), but switching to integrase inhibitors from a high genetic barrier drug during successful treatment was not supported (mITT OR 1.43; 95% CI 0.89–2.31). Integrase inhibitor-based regimens result in similar immunological responses compared to other regimens. A low genetic barrier to drug-resistance development was observed for raltegravir and elvitegravir, but not for dolutegravir.

Conclusion

In first-line therapy, integrase inhibitors are superior to other regimens. Integrase inhibitor use after virological failure is supported as well by the meta-analysis. Careful use is however warranted when replacing a high genetic barrier drug in treatment-experienced patients switching successful treatment.

Tolerability of HIV integrase inhibitors

PURPOSE OF REVIEW

This review discusses the available safety data for three integrase strand transfer inhibitors (INSTIs)--raltegravir, elvitegravir and dolutegravir--derived from studies in both HIV-infected and HIV-uninfected cohorts.

RECENT FINDINGS

Phase 2 and 3 clinical trials show that all three INSTIs are well tolerated in treatment-naive and treatment-experienced patients with headache and gastrointestinal effects being the most commonly reported adverse events. Other nervous system (including neuropsychiatric) effects are often reported with INSTIs but are milder and less frequent than with efavirenz. Limited data suggest that effects upon lipid metabolism with raltegravir and dolutegravir are favourable compared with efavirenz and protease inhibitors, with more variable findings for elvitegravir because of coadministration with the boosting agent cobicistat. Cobicistat and dolutegravir have effects upon proximal renal tubular function causing mild-to-moderate creatinine elevation. Rare and severe events possibly related to INSTIs include systemic hypersensitivity reactions and rhabdomyolysis.

SUMMARY

INSTIs are an important recent addition to the antiretroviral armamentarium, with good short-term and medium-term safety. Long-term data from ongoing clinical studies are needed for a definitive assessment of their safety profile.

Creatine kinase elevation in HIV-1-infected patients receiving raltegravir-containing antiretroviral therapy: a cohort study

OBJECTIVES

To evaluate the incidence and risk factors for significant creatine kinase elevation in HIV-1-infected patients who were prescribed a raltegravir-containing antiretroviral therapy.

DESIGN

A retrospective analysis of a prospectively collected cohort involving all consecutive patients who were prescribed a raltegravir-containing antiretroviral regimen between June 2005 and December 2010.

METHODS

Significant creatine kinase elevation was defined as an elevation of at least 3-fold from the upper limit of normal (ULN) (grade 2, WHO classification) while receiving raltegravir. Blood analysis at each visit included at least creatine kinase, as well as plasma HIV-1 RNA and CD4 cell count.

RESULTS

There were 475 patients who had been exposed to raltegravir for a median of 11.5 (IQR 8.2-15.2) months. An increase of creatine kinase ≥ 3-fold ULN was detected in 53 (11.2%) patients, representing an incidence of 3.8/100 person-years. Symptoms were reported by seven patients (1.5%), they showed either grade 1 (n = 3) or 2 (n = 4) creatine kinase increases. The median duration of raltegravir therapy before creatine kinase elevation was 5.9 (IQR 3.3-9.3) months. Evidence of creatine kinase elevation prior to raltegravir therapy [hazard ratio (HR) 3.30; 95% CI 1.59 ± 6.86; P = 0.001], abnormal baseline creatine kinase (HR 3.24; 95% CI 1.63 ± 6.45; P = 0.001) and male gender (HR 4.17; 95% CI 1.33 ± 1.27; P = 0.001) were identified as independent risk factors for creatine kinase elevation during raltegravir treatment.

CONCLUSIONS

Although ≈ 1 in 10 patients on raltegravir therapy developed significant creatine kinase elevation as defined in this study, symptoms were uncommon, not severe and occurred in patients with easily identifiable risk factors.

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.

Update on raltegravir and the development of new integrase strand transfer inhibitors

Raltegravir (RAL) is the first antiretroviral in the integrase strand transfer inhibitors (INSTI) class. The use of RAL has expanded since its approval in October 2007 for multidrug-resistant human immunodeficiency virus type 1 infection in adults. RAL is now a guideline-preferred treatment option for antiretroviral-naïve patients, indicated for treatment in adolescents, and is being studied as an integral part of nucleoside sparing regimens. The development of resistance and the need for a once-daily dosing option has led to the development of new INSTIs, including elvitegravir and dolutegravir. Elvitegravir is being studied in a promising once-daily single-tablet regimen with tenofovir, emtricitabine, and the investigational pharmacoenhancer cobicistat. The development of cobicistat and the new once-daily INSTIs may revolutionize the treatment of human immunodeficiency virus type 1 infection. This article reviews the current literature on raltegravir and new developments in the INSTI class.

Role of raltegravir in HIV-1 management

OBJECTIVE

To review the literature concerning the role of raltegravir in the treatment of HIV-1 in antiretroviral (ARV)-experienced and ARV-naïve patients.

DATA SOURCES

A PubMed search was conducted for published data through March 2012 using the search terms raltegravir, MK-0518, and integrase strand transfer inhibitor. An additional search of International Pharmaceutical Abstracts for unpublished data, including data from the Infectious Diseases Society of America, the Conference on Retroviruses and Opportunistic Infections, the International AIDS Society, and the Interscience Conference on Antimicrobial Agents and Chemotherapy, was conducted using similar search terms.

STUDY SELECTION AND DATA EXTRACTION

In vitro and in vivo Phase 2, Phase 3, and postmarketing studies available in English, evaluating antiretroviral regimens that contain raltegravir for the treatment of HIV-1 infection in both ARV-naïve and ARV-experienced patients, were evaluated. Studies assessing raltegravir pharmacokinetics and pharmacodynamics were included for review.

DATA SYNTHESIS

The nucleoside-based regimen of raltegravir with tenofovir/emtricitabine provides an effective first-line treatment option. However, nucleoside-sparing regimens appear unfavorable in ARV-naïve subjects and should be reserved for patients with limited treatment options. Raltegravir used with optimized background therapy provides an alternative regimen for ARV-experienced patients. This review describes the available in vitro and in vivo data on raltegravir potency, defined as the ability to achieve undetectable viral load, and safety profile, as well as comparison to standard HIV-1 therapies.

CONCLUSIONS

Raltegravir has demonstrated potent antiretroviral activity against HIV-1 in both ARV-naïve and ARV-experienced subjects, with the benefits of a favorable adverse effect profile and minimal drug interactions. Raltegravir must be dosed twice daily, as once daily raltegravir displays decreased virologic efficacy compared to twice daily dosing. However, the ongoing development of new integrase strand transfer inhibitors may provide potent once daily regimens.

Raltegravir in HIV-1 infection: Safety and Efficacy in Treatment-naïve Patients

The hunt for a compound which inhibits the HIV-1 integrase had been painstakingly difficult. Integrase is essential for viral replication as it mediates the integration of the viral DNA genome into the host DNA resulting in the establishment of the permanent provirus. Persistent efforts have resulted in the discovery of Raltegravir (Isentress, MK-0518), the first integrase inhibitor approved by US Food and Drug Administration for the treatment in HIV-1 infected patients. Numerous clinical studies with raltegravir have found it to be safe and effective in treatment naïve as well as treatment experienced patients. Adverse events associated with raltegravir based therapy are milder compared to previously available regimens. Raltegravir is metabolized primarily via glucuronidation mediated by uridine diphosphate glucuronosyltransferase and has a favorable pharmacokinetics independent of age, gender, race, food, and drug-drug interactions. Within a short period of time of its introduction, raltegravir has been included as one of DHHS recommended preferred regimen for the treatment of HIV-1 infection in treatment naïve patients.