A nucleoside- and ritonavir-sparing regimen containing atazanavir plus raltegravir in antiretroviral treatment-naïve HIV-infected patients: SPARTAN study results

Two-drug regimens for HIV treatment

Combination therapy with three antiretroviral agents has been integral to successful HIV-1 treatment since 1996. Although the efficacy, adverse effects, and toxicities of contemporary three-drug regimens have improved, even the newest therapies have potential adverse effects. The use of two-drug regimens is one way to reduce lifetime exposure to antiretroviral drugs while maintaining the benefits of viral suppression. Multiple large, randomised trials have shown the virological non-inferiority of certain two-drug regimens versus three-drug comparators, including adverse effect differences that reflect known profiles of the antiretroviral drugs in the respective regimens. Two-drug combinations are now recommended in treatment guidelines and include the first long-acting antiretroviral regimen for the treatment of HIV-1. Recommended two-drug regimens differ in their risks for, and factors associated with, virological failure and emergent resistance. The tolerability, safety, metabolic profiles, and drug interactions of two-drug regimens also vary by the constituent drugs. No current two-drug regimen is recommended for people with chronic hepatitis B virus as none include tenofovir. Two-drug regimens have increased options for individualised care.

Risks and benefits of reducing the number of drugs to treat HIV-1 infection

Introduction: Despite the efficacy and safety of antiretroviral therapy, new treatment options are needed to address the concerns of patients and physicians regarding long-term toxicities, costs, and convenience of lifelong antiretroviral therapy. To achieve this goal, one strategy is to reduce the number of drugs in the antiretroviral regimen.Areas covered: We review the recent evidence on the efficacy and safety of reduced drug regimens and their potential risks and benefits. There is currently strong evidence showing that some two-drug regimens have a comparable efficacy and short-term safety compared to standard three-drug regimens. The fixed-dose combination of dolutegravir/lamivudine is already an alternative for many treatment-naïve and virologically suppressed HIV-1 infected adults supported by large randomized clinical trials. The co-formulation dolutegravir plus rilpivirine is also a switch strategy for maintenance therapy. Long-acting injectable cabotegravir plus rilpivirine has already regulatory approval, and islatravir plus doravirine is an expected option in the near future. Some two-drug regimens have not been as successful.Expert opinion: Long-term safety issues of these two-drug regimens remain to be determined, but with the overwhelming evidence available in virological control and short-term safety, the potential benefits of some of these two-drug regimens appear to outweigh the risks.

Risk of failure in dual therapy versus triple therapy in naïve HIV patients: a systematic review and meta-analysis

OBJECTIVES

Several attempts have been made to test different drug-sparing strategies to reduce the drug-burden and drug-related toxicities. The objective of this meta-analysis was to evaluate the relative risk (RR) of failure of dual therapies compared to triple therapies in HIV-naïve patients.

METHODS

We searched MEDLINE, Google Scholar and the Cochrane Library. The following criteria were used: present data from original articles comparing the two treatment regimens; published from January 2007 up to January, 2020. No language or study design restriction was applied. Subjects were HIV-positive naïve patients treated with dual or triple antiretroviral therapy (ART). A systematic review and meta-analysis was performed. Treatment failure (TF) was the primary outcome evaluated; heterogeneity was assessed using the Q statistic and I².

RESULTS

Fourteen studies were included, allowing a meta-analysis on 5205 patients. The meta-analysis performed on studies that presented data at 48 weeks showed that the RR of TF (RR > 1 favouring triple therapy) in 10 studies was 1.20 (95% confidence interval (CI): 0.91-1.59, I²: 49.2%); the RR of virological failure (VF) in eight studies was 1.54 (95% CI: 0.84-2.86, I²: 54%); the RR of adverse drug reaction leading to discontinuation of the regimen at 48 weeks in eight studies was 0.76 (95% CI: 0.43-1.33, I²: 17.7%). In patients with less than 200 CD4+, the RR of TF in two studies without maraviroc was 2.09 (95% CI: 1.05-4.17, I²: 0.0%). Regarding the studies at 96 weeks there was no difference except in rate of development of resistance, RR 1.94 (95% CI: 1.06-3.53, I²: 6.2%).

CONCLUSION

Dual therapies are as effective as those with three drugs, showing no difference according to the different dual therapies, except in patients with less than 200 CD4; however, they are associated with a higher selection of resistance-associated mutations at 96 weeks of therapy.

Non-Nucleoside Reverse Transcriptase Inhibitors Join Forces with Integrase Inhibitors to Combat HIV

In the treatment of acquired immune deficiency syndrome (AIDS), the diarylpyrimidine (DAPY) analogs etravirine (ETR) and rilpivirine (RPV) have been widely effective against human immunodeficiency virus (HIV) variants that are resistant to other non-nucleoside reverse transcriptase inhibitors (NNRTIs). With non-inferior or improved efficacy, better safety profiles, and lower doses or pill burdens than other NNRTIs in the clinic, combination therapies including either of these two drugs have led to higher adherence than other NNRTI-containing treatments. In a separate development, HIV integrase strand transfer inhibitors (INSTIs) have shown efficacy in treating AIDS, including raltegravir (RAL), elvitegravir (EVG), cabotegravir (CAB), bictegravir (BIC), and dolutegravir (DTG). Of these, DTG and BIC perform better against a wide range of resistance mutations than other INSTIs. Nevertheless, drug-resistant combinations of mutations have begun to emerge against all DAPYs and INSTIs, attributable in part to non-adherence. New dual therapies that may promote better adherence combine ETR or RPV with an INSTI and have been safer and non-inferior to more traditional triple-drug treatments. Long-acting dual- and triple-therapies combining ETR or RPV with INSTIs are under study and may further improve adherence. Here, highly resistant emergent mutations and efficacy data on these novel treatments are reviewed. Overall, ETR or RPV, in combination with INSTIs, may be treatments of choice as long-term maintenance therapies that optimize efficacy, adherence, and safety.

Two's a Company, Three's a Crowd: A Review of Initiating or Switching to a Two-Drug Antiretroviral Regimen in Treatment-Naïve and Treatment-Experienced Patients Living with HIV-1

INTRODUCTION

As HIV has become a manageable chronic condition, a renewed and increased interest in challenging traditional three-drug HIV therapies and moving toward two-drug regimens (2DR) for initial or maintenance treatment in people living with HIV (PLWH) has developed. As PLWH are living longer, continual advancements in antiretroviral regimens have been a focus to provide optimal life-long therapy options. Although early studies may have shown poor outcomes in virologic suppression with 2DR, newer studies and treatment options have emerged to show promise in the management of HIV. The purpose of this review is to evaluate current literature and assess the efficacy of two-drug (2DR) antiretroviral therapy in treatment-naïve and -experienced people living with HIV.

METHODS

A systematic search was performed between January 2009 to January 2020, using EMBASE, MEDLINE, Google Scholar, and bibliographies. Combinations of the following search terms were used: HIV-1 infection, antiretroviral therapy, dual therapy, two-drug regimen, two-drug therapy, two-drug regimen, and 2DR. Included studies were those in the adult population with at least one active comparator, outcomes assessing HIV-1 RNA viral load while on treatment, and written in English.

RESULTS

Thirty-three studies were included, 13 where 2DRs were evaluated as initial therapy (3 studies with extension data) and 15 where 2DRs were evaluated as maintenance or switch therapy (2 studies with extension data).

CONCLUSION

Although 2DRs may not be appropriate in all patient populations, they are being utilized more frequently and have the potential to reduce costs, adverse effects, and drug interactions.

Dolutegravir And Lamivudine Combination For The Treatment Of HIV-1 Infection

There have been remarkable advances in drug development for the treatment of HIV-1 infection. From the co-formulation of combination antiretroviral therapy (cART) into single-tablet regimens to the development of long-acting antiretroviral (ARV) drug formulations, the treatment of HIV has and will become much more tolerable and less complicated for patients. In addition, and appropriately, there is a focus on reducing short- and long-term toxicities of treatment while maintaining robust efficacy. One of such approaches includes 2-drug regimen constructs that contain and retain effective ARV compounds while excluding components that have relatively unfavorable toxicity profiles. The first-ever 2-drug regimen approved for the treatment of HIV-1 infection for treatment-naive people living with HIV (PLWH), consisting of the integrase inhibitor dolutegravir (DTG) and the nucleoside reverse transcriptase inhibitor (NRTI) lamivudine (3TC), is reviewed in this paper. The chemical composition and properties, pharmacokinetic and pharmacodynamics profile, and clinical trial data on efficacy and safety of DTG/3TC are presented. An expert opinion aims to highlight important considerations for the use of DTG/3TC in the context of existing and emerging ARV options.

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.

New Strategies of ARV: the Road to Simplification

PURPOSE OF REVIEW

Simplification of antiretroviral therapy is a strategy aiming to reduce pill burden, drug interactions, and toxicity. This review focuses on the most recent and important studies evaluating a reduction on the number of drugs for HIV treatment, both in naive and virologically suppressed patients.

RECENT FINDINGS

Interesting studies have been performed in the past years testing dual therapy and monotherapy, with variable rates of virological control. Novel therapeutics like immunotherapy or long-acting antiretrovirals can also be considered for simplification. Reducing the number of drugs for HIV treatment can be an option for selected patients. Current available evidence favors dual therapy over monotherapy. Future research should seek to identify the best candidates for simplification.

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.

Real-life study of dual therapy based on dolutegravir and ritonavir-boosted darunavir in HIV-1-infected treatment-experienced patients

BACKGROUND

Dual therapy based on dolutegravir and ritonavir-boosted darunavir (DTG/DRV/r) is a combination of well-known drugs with a high genetic barrier to HIV resistance.

METHOD

A retrospective analysis of all HIV-1 infected treatment-experienced patients who switched to DTG/DRV/r from May 2014 till March 2017 in 4 Polish centres-results of a 48-week treatment.

RESULTS

The study group consisted of 59 men and 17 women. Median baseline parameters were: age- 42.7 years, CD4 cells count- 560.5 cells/μl, CD4 cells nadir- 150 cells/μl, number of prior antiretroviral regimens- 3. The introduction of dual therapy was primarily due to virologic failure (30 patients), adverse events on previous regimens (17 patients) and therapy simplification (27 patients). At week 48 the treatment was continued in 70/76 of patients and the median CD4 cells count increased from 560.5 to 641.0 cells/μl. The therapy was discontinued in six patients (1 -virologic failure, 1 -decrease of estimated glomerular filtration rate (eGFR), 1 -myalgia, 3 -lost to follow-up). At week 48 six patients had detectable viremia, but only in one patient viremia was higher than 200 copies/ml. At week 48 the level of serum total cholesterol of the investigated subjects was statistically significantly higher than at the moment of dual therapy introduction (185.8 mg/dl vs. 174.8 mg/dl- p<0.05). However, in patients previously not treated with TDF, there were no changes in lipid parameters during therapy. Proteinuria was observed in 13.2% of patients before the switch to dual therapy and in 7.1% of patients at week 48.

CONCLUSIONS

The investigated dual therapy was effective and safe. The observed increase in lipid parameters only concerned the patients who had used a TDF-based regimen prior to analysed dual treatment.

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.

Dolutegravir/rilpivirine for the treatment of HIV-1 infection

Much progress has been made in the development of antiretroviral therapies (ARTs) for HIV-1 infection. Beginning a little over a decade ago, single tablet combination regimens (STRs) became available, and subsequently, newer STR formulations with improved safety profiles have emerged. Recently, there is a growing interest in regimen simplification with the primary goal of further reducing long-term toxicities of ART and improving medication adherence. Dolutegravir/rilpivirine (DTG/RPV) was approved by the US Food and Drug Administration (FDA) as the first dual antiretroviral STR for the maintenance therapy of HIV-1 infection. Following an extensive review of all published papers on RPV and DTG, administered alone and in combination, extracted from databases including PubMed, Google scholar, and EMBASE, as well as drug package inserts and conference abstracts and proceedings, this review discusses the chemical properties and composition, pharmacodynamics and pharmacokinetic properties, clinical trial efficacy and safety data, as well as important drug-drug interactions associated with DTG/RPV. An expert opinion section discusses ideal candidates for DTG/RPV in the context of available but limited data and in comparison to currently available and emerging ART alternatives.

Two-drug regimens for treatment of naïve HIV-1 infection and as maintenance therapy

As people live longer with HIV infection, there has been a resurgence of interest in challenging the use of three-drug therapy, including two nucleoside reverse transcriptase inhibitors plus a third drug, as initial treatment of HIV infection or for maintenance therapy in virologically suppressed individuals. Although initial studies showed poor efficacy and/or substantial toxicity, more recent regimens have held greater promise. The SWORD-1 and -2 studies were pivotal trials of dolutegravir plus rilpivirine as maintenance therapy in virologically suppressed patients with no history of drug resistance, leading to the US Food and Drug Administration’s approval of the regimen as a small, single tablet. More recently, the GEMINI-1 and -2 studies demonstrated that dolutegravir plus lamivudine is as safe and effective as the same regimen when combined with tenofovir disoproxil fumarate in treatment-naïve individuals. Together, these and other studies of novel two-drug regimens offer the potential for improved tolerability and simplicity, as well as a reduction in cost. We will review historical and recent trials of two-drug therapy for the treatment of HIV-1 infection.

Comparison of 48-week efficacies of elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide and nucleoside/nucleotide reverse transcriptase inhibitor-sparing regimens: a systematic review and network meta-analysis

OBJECTIVES

To compare nucleoside/nucleotide reverse transcriptase inhibitor (NRTI)-sparing regimens with tenofovir alafenamide (TAF)-based combinations in HIV-1-infected adults, we performed a network meta-analysis (NMA) to provide estimates of relative efficacy for these two regimens.

METHODS

A systematic literature review (SLR) was performed to identify phase 3/4 randomized controlled clinical trials evaluating the efficacy of commonly used combination antiretroviral therapy (cART) including an NRTI backbone or that of commonly used NRTI-sparing regimens. A Bayesian random-effect model was used to compare virological suppression rates at 48 weeks for NRTI-sparing regimens and elvitegravir/cobicistat/emtricitabine/TAF (E/C/F/TAF).

RESULTS

Twenty-three studies in treatment-naïve patients identified by the SLR were included in the NMA, including four studies assessing NRTI-sparing regimens. In treatment-naïve patients, the probability of achieving virological suppression at 48 weeks was between 40% and 60% higher with E/C/F/TAF than with NRTI-sparing strategies. The credible interval vs. darunavir/ritonavir (DVR/r) + raltegravir (RAL) and LPV/r monotherapy did not include 1. In the subgroup of naïve patients with viral load < 100 000 HIV-1 RNA copies/mL, a credible difference was found between NRTI-sparing treatments and E/C/F/TAF. Studies in treatment-experienced patients were too heterogeneous to allow for an NMA.

CONCLUSIONS

The NMA results suggest that E/C/F/TAF represents a more effective option than NRTI-sparing regimens in terms of 48-week efficacy in treatment-naïve patients. Furthermore, TAF pharmacological properties, as well as tolerability results in clinical studies, suggest a safety profile similar to that of NRTI-sparing regimens. Thus, the E/C/F/TAF combination might represent a more appropriate option than NRTI-sparing regimens for initiation of antiretroviral therapy in treatment-naïve HIV-infected patients.

Impact of UGT1A1 polymorphisms on Raltegravir and its glucuronide plasma concentrations in a cohort of HIV-1 infected patients

The aim of this study was to evaluate the effect of UGT1A1 polymorphisms on Raltegravir (RAL) and its metabolite RAL-glucuronide trough plasma concentrations ([RAL]plasma and [RAL-glu]plasma) and on the metabolic ratio (MR): [RAL-glu]plasma/[RAL]plasma. UGT1A1 genotyping was performed on 96 patients. 44% (n = 42) were homozygous UGT1A1*1/*1 while 50% (n = 48) and 6% (n = 6) were UGT1A1*28 and UGT1A1*36 carriers, respectively. The median concentration and interquartile range (IQR) of [RAL]plasma were 88.5 ng/ml (41.0-236), 168 ng/ml (85.8-318) and 92.5 ng/ml (36.4-316) for UGT1A1*1/*1, UGT1A1*28 and UGT1A1*36 carriers, respectively. Only the difference between UGT1A1*1/*1 and *28 carriers was statistically significant (p = 0.022). The median MR (IQR) were 5.8 (3-10), 2.9 (1.6-5.3) and 3.2 (1.7-5.9) for UGT1A1*1/*1, UGT1A1*28 and UGT1A1*36 carriers, respectively. Only the difference between UGT1A1*1/*1 and *28 carriers was statistically significant (p = 0.004) with an allele-dependent effect: UGT1A1*28 homozygous having lower MR than heterozygous carriers who show lower MR compared to *1/*1. Except for the sensation of fatigue, this PK effect did not correlate with clinical adverse events or biological abnormalities. In Conclusion, we demonstrate that UGT1A1*28 polymorphism has a significant impact on RAL metabolism: UGT1A1*28 carriers being characterized by higher [RAL]plasma and lower MR.

Current and emerging two-drug approaches for HIV-1 therapy in ART-naïve and ART-experienced, virologically suppressed patients

INTRODUCTION

Current guidelines recommend a 2-drug antiretroviral regimen as an alternative to triple antiretroviral therapy (ART) in selected patients to reduce long-term toxicity and costs.

AREAS COVERED

This review is intended to provide insight into the efficacy, safety and tolerability of 2-drug versus 3-drug ART in naïve and in treatment-experienced virologically-suppressed patients.

EXPERT OPINION

Dual therapy regimens are not feasible in HBV-coinfected individuals and should not be applied during pregnancy. Positive data on 2-drug ART in drug naïve patients are still limited, while, in virologically-suppressed individuals, several regimens have shown non-inferiority as compared to 3-drug regimens. The strongest evidence of efficacy applies to ritonavir-boosted PI regimens combined with lamivudine and to dolutegravir with rilpivirine. Dual therapies showed improved renal function and bone mineral density over tenofovir disoproxil fumarate-based 3-drug regimens. There are also great expectations for ongoing phase 3 trials testing dolutegravir with lamivudine. New and future single tablet co-formulations of dual regimens are expected to improve their suitability. Despite the lack of comparison with tenofovir alafenamide-based 3-drug regimens, the 2-drug regimens showing consistent non-inferiority and safety versus 3-drug regimens will challenge the current paradigm of 3-drug ART.

Efficacy and safety of nucleoside-sparing regimen based on raltegravir and ritonavir-boosted darunavir in HIV-1-infected treatment-experienced patients

AIM

To assess the efficacy and tolerability of dual therapy containing raltegravir (RAL) and ritonavir boosted darunavir (DRV/r) in HIV-1-infected treatment-experienced patients.

METHOD

Retrospective analysis of 81 HIV-1-infected treatment-experienced patients (56 male and 25 female, 5 Polish centers) who switched to RAL/DRV/r.

RESULTS

The main reasons for the introduction of dual therapy were renal dysfunction (16/81 patients-19.8%) and virologic failure on previous regimens (15/81 patients-18.5%). At 48 weeks the treatment was continued in 58/81 (71.6% of patients). In three patients the therapy was discontinued because of virologic failure. However, no mutations to DRV or integrase inhibitors (InI) were detected. At 48 weeks of treatment CD4⁺ lymphocyte count increased statistically significantly (median 121 cells/μL) P < 0.005. The main reasons for the discontinuation of therapy were treatment simplification (11/23-47.8% patients), adverse events (7/23 patients 30.4%), virologic failure (3/23 patients 13.0%). All patients who switched to RAL/DRV/r therapy because of prior renal impairment were maintained on the treatment for 48 weeks. In this group, before the introduction of dual therapy eGFR (estimated glomerular filtration rate) <60 mL/min/1.72 m² was reported in nine patients and after 48 weeks in four patients (56.3% vs 25%) (P > 0.05). We found a statistically significant decrease in the prevalence of proteinuria or eGFR <60 mL/min/1.72 m² (93.8% vs 37.5%; P = 0.004 before and after the introduction of dual therapy, respectively).

CONCLUSIONS

Dual therapy was effective and safe for the vast majority of antiretroviral-experienced subjects. Such therapy can be recommended especially for patients with renal impairment or NRTIs intolerance.

Nucleoside reverse transcriptase inhibitor-reducing strategies in HIV treatment: assessing the evidence

Antiretroviral (ARV) therapy, comprising a backbone of two nucleos(t)ide reverse transcriptase inhibitors (NRTIs) plus another ARV, is the recognized standard of care (SOC), which has helped extend life expectancy in people living with HIV. In a quest to reduce lifelong drug exposure and minimize or avoid the toxicity of NRTIs, "NRTI-reducing" regimens have been investigated. This descriptive review assessing the results of NRTI-reducing strategies from the largest randomized trials focuses on virological efficacy, resistance, regimen safety (in terms of bone mineral density, renal function, lipids and central nervous system function) and simplicity. The review considers efficacy across various NRTI-sparing strategies, for example an integrase strand transfer inhibitor (INSTI) plus a ritonavir-boosted protease inhibitor (PI/r) or PI/r + lamivudine (3TC), in both naïve and switch regimes. Of 10 key studies in treatment-naïve adults assessing five NRTI-reducing strategies, only four studies demonstrated noninferiority vs. SOC [GARDEL, NEAT 001, AIDS Clinical Trials Group 5142 and PROGRESS]. In switch settings, 17 studies (10 randomized) were reviewed that used four strategies, including three studies assessing an INSTI plus a nonnucleoside reverse transcriptase inhibitor . Noninferiority of the NRTI-reducing arm was shown in six of 10 studies (ATLAS-M, SALT, DUAL, OLE, LATTE-2 and SWORD). In general, NRTI-reducing therapy did not always result in an improvement in short- or long-term adverse events; however, in many cases, these endpoints were not reported. Some of these studies reported higher virological failure rates with more frequent emergence of resistance mutations. None of these NRTI-reducing strategies has been compared against a single-pill regimen, including those containing tenofovir alafenamide. Only strategies demonstrating noninferior efficacy, a benefit in safety/tolerability, and a favourable cost-efficacy ratio, preferably in a single pill, will eventually match the current SOC of triple ARV therapy.

Dual antiretroviral therapy for HIV infection

INTRODUCTION

For two decades, triple combinations of antiretrovirals have been the standard treatment for HIV infection. The challenges of such lifelong therapy include long-term side effects, high costs and reduced drug adherence. The recent advent of more potent and safer antiretrovirals has renewed the interest for simpler HIV regimens. Areas covered: We discuss the pros and cons of dual antiretroviral therapies in both drug-naïve and in treatment-experienced patients with viral suppression (switch strategy). Expert opinion: Some dual antiretroviral regimens are safe and efficacious, particularly as maintenance therapy. At this time, combinations of dolutegravir plus rilpivirine represent the best dual regimen. Longer follow-up and larger study populations are needed before supporting dolutegravir plus lamivudine. In contrast, dual therapy based on maraviroc is less effective. Although dual regimens with boosted protease inhibitors plus either lamivudine or raltegravir may be effective, they are penalized by metabolic side effects and risk for drug interactions. The newest dual regimens could save money, reduce toxicity and spare drug options for the future. For the first time in HIV therapeutics, less can be more. Dual therapy switching has set up a new paradigm in HIV treatment that uses induction-maintenance.

HIV viral kinetics and T cell dynamics in antiretroviral naïve persons starting an integrase strand transfer inhibitor and protease inhibitor regimen

BACKGROUND

Nucleos(t)ide reverse transcriptase inhibitor (NRTI)-sparing regimens may potentially minimize antiretroviral (ART) toxicities, but demonstrate mixed efficacy and toxicity results. The impact of an integrase strand transfer inhibitor (INSTI) and protease inhibitor (PI) regimen on HIV viral dynamics and T cell kinetics remains underdescribed.

OBJECTIVE

To compare the effect of raltegravir + ritonavir boosted lopinavir (RAL + LPV/r) to efavirenz/tenofovir disoproxil fumarate/emtricitabine (EFV/TDF/FTC) on HIV kinetics and T cell dynamics.

METHODS

Fifty participants naïve to ART underwent HIV viral kinetic sampling evaluated using biexponential mixed effects modeling. A subset of 28 subjects (with complete viral suppression) underwent flow cytometry and evaluation of soluble markers of inflammation at weeks 0, 4, and 48 of ART.

RESULTS

RAL + LPV/r compared to EFV/TDF/FTC resulted in a prolonged first phase viral decay rate (18 vs. 13 days p < 0.01). From weeks 0 to 4, RAL + LPV/r was associated with a trend toward greater decreases in activated CD4⁺ T cells (-3.81 vs. -1.18 p = 0.09) and less decreases in activated effector memory CD4⁺ T cells (-0.63 vs. -2.69 p-0.07). These trends did not persist to week 48. No differences were noted at any time point for soluble markers of immune activation.

CONCLUSIONS

The prolonged first phase viral decay observed with RAL + LPV/r in persons starting ART did not result in differences in viral suppression at week 48. We also observed trends in declines in certain cellular markers of immune activation but it remains unclear if this could translate to long-term immunologic benefits in persons on an INSTI + PI.

Two-Drug Treatment Approaches in HIV: Finally Getting Somewhere?

The advent of combination antiretroviral therapy (ART) has significantly decreased AIDS-related morbidity and mortality. Nevertheless, the benefits of ART are only realized through adherence to lifelong treatment. Though contemporary antiretroviral (ARV) drugs have fewer adverse effects in comparison to older ARV drugs, many agents are associated with negative or unknown long-term effects. There is increasing evidence that two-drug (dual-therapy) regimens may be an effective alternative to the currently recommended three-drug (triple-therapy) regimens. In this review, we provide a comprehensive and critical review of recently completed and ongoing trials of dual-therapy regimens in treatment-naïve and treatment-experienced HIV-1-infected patients. We also review current HIV/AIDS society recommendations regarding dual therapy as well as future therapeutic possibilities.

Efficacy, safety and pharmacokinetics of atazanavir (200mg twice daily) plus raltegravir (400mg twice daily) dual regimen in the clinical setting

BACKGROUND

Unboosted atazanavir with raltegravir has been investigated at 300mg twice daily showing frequent hyperbilirubinemia and selection of resistance-associated mutations.

OBJECTIVES

Atazanavir 200mg twice daily could increase tolerability and plasma exposure.

STUDY DESIGN

Patients on atazanavir/raltegravir (200/400 twice daily), with self-reported adherence >95% and no concomitant interacting drugs were retrospectively evaluated.

RESULTS

102 patients [72.5% male, age 46.4 years (42-54), BMI 24kg/m² (22-26)] were included. CD4+ T lymphocytes were 417 cell/μL (302-704) and 76 patients (74.5%) had HIV-RNA <50 copies/ml. After 123 weeks 18.6% patients showed virological failure and 3.9% discontinued for intolerance. Available genotypes showed selection of major integrase (7/10 patients) and protease resistance-associated mutations (5/13 patients). In patients switching with dyslipidemia (n=67) total, LDL cholesterol and triglycerides significantly decreased. Patients switching with eCRCL<60ml/min (n=27) had no significant changes while patients with eCRCL >60ml/min showed significant decrease (-9.8ml/min, p=0.003) at 96-weeks. Atazanavir and raltegravir trough concentrations were 321ng/mL (147-720) and 412ng/mL (225-695). Self-reported non-adherence (n=4) was significantly associated with virological failure (p=0.02); patients with virological success had borderline longer previous virological control (33 vs. 18 months, p=0.07).

DISCUSSION

Switch to atazanavir/raltegravir was safe and well tolerated allowing optimal drugs' plasma exposure. However, a concerning rate (18.6%) failed with newly selected mutations and stopped ATV/RAL because of DDI and intolerance issues or were lost to follow-up. This regimen might be considered in selected patients, without history of protease inhibitors failure or HBV infection, showing optimal adherence and prolonged suppression.

Population pharmacokinetic modelling of the changes in atazanavir plasma clearance caused by ritonavir plasma concentrations in HIV-1 infected patients

AIMS

The aim of the present study was to develop a simultaneous population pharmacokinetic model for atazanavir (ATV) incorporating the effect of ritonavir (RTV) on clearance to predict ATV concentrations under different dosing regimens in HIV-1-infected patients.

METHODS

A Cross-sectional study was carried out in 83 HIV-1-infected adults taking ATV 400 mg or ATV 300 mg/RTV 100 mg once daily. Demographic and clinical characteristics were registered and blood samples collected to measure drug concentrations. A population pharmacokinetic model was constructed using nonlinear mixed-effects modelling and used to simulate six dosing scenarios.

RESULTS

The selected one-compartmental model described the pharmacokinetics of RTV and ATV simultaneously, showing exponential, direct inhibition of ATV clearance according to the RTV plasma concentration, which explained 17.5% of the variability. A mean RTV plasma concentration of 0.63 mg l-1 predicted an 18% decrease in ATV clearance. The percentages of patients with an end-of-dose-interval concentration of ATV below or above the minimum and maximum target concentrations of 0.15 mg l-1 and 0.85 mg l-1 favoured the selection of the simulated ATV/RTV once-daily regimens (ATV 400 mg, ATV 300 mg/RTV 100 mg, ATV 300 mg/RTV 50 mg, ATV 200/RTV 100 mg) over the unboosted twice-daily regimens (ATV 300 mg, ATV 200 mg).

CONCLUSIONS

A one-compartment simultaneous model can describe the pharmacokinetics of RTV and ATV, including the effect of RTV plasma concentrations on ATV clearance. This model is promising for predicting individuals' ATV concentrations in clinical scenarios, and supports further clinical trials of once-daily doses of ATV 300 mg/RTV 50 mg or ATV 200 mg/RTV 100 mg to confirm efficacy and safety.

Switch to Ritonavir-Boosted versus Unboosted Atazanavir plus Raltegravir Dual-Drug Therapy Leads to Similar Efficacy and Safety Outcomes in Clinical Practice

Objectives

To assess immunovirological response, safety and pharmacokinetic of NRTI-sparing regimen dual therapy of atazanavir (ATV) and raltegravir (RAL) in maintenance strategy.

Methods

A retrospective analysis was conducted on a cohort of HIV-infected adults followed in French centers (Dat’AIDS cohort), comparing the proportions of virological and therapeutic failures between ATV + RAL and ATV/ritonavir + RAL dual therapy regimens.

Results

283 patients were assessed: 185 switched for ATV + RAL and 98 for ATV/ritonavir + RAL dual therapy. Virological failure rate at week 96 was 13.8% (95% CI, 9.8–17.8), without difference between the two groups (Log-rank Test, p = 0.87). The cumulative percentages of patients remaining free of therapeutic failure at week 24, 48 and 96 of dual therapy were 74.9% (95% CI, 69.9–80.0), 65.4% (95% CI, 59.8–70.9) and 53.4% (95% CI, 47.5–59.2), respectively. Four out of 39 confirmed virological failures developed RAL resistance. By multivariate analysis, virological failure was associated with high HIV-1 RNA zenith (p = 0.02), low CD4+ T-cell count at baseline (p<0.001) and short duration on antiretroviral therapy (p<0.001). Before week 96, dual therapy was discontinued in 44 patients (16%) because of various adverse events, with no difference between the two groups. Minimal plasma levels were targeted in 84% and 87% of patients for ATV and RAL, respectively, and both were significantly higher in ritonavir-boosted regimen.

Conclusions

Emerging RAL-resistance and discontinuations for adverse events resulted in moderate efficacy rates of ATV and RAL dual therapy in heavily pretreated patients.

Immunovirological Efficacy of Once-Daily Maraviroc Plus Ritonavir-Boosted Atazanavir After 48 Weeks in Naive HIV-Infected Patients

Toxicities related to the use of nucleoside analogues have increased the interest in developing nucleoside-sparing regimens, mainly combining protease inhibitors with raltegravir. However, data regarding the use of CCR5-antagonists in this setting and in the naive scenario are scarce. The main objective was to analyze the immunovirological efficacy and tolerability of a low-dose, once-daily, maraviroc (MVC)-containing, nucleoside reverse transcriptase inhibitor-sparing dual therapy compared with standard triple therapy after 48 weeks for naive HIV-infected patients in the routine clinical practice setting. All naive HIV-infected patients with stable clinical condition that started antiretroviral treatment since February 1, 2008 to May 30,h 2012 were included. MVC clinical test was used to select candidate subjects to MVC therapy. Thirty-two subjects with MVC + atazanavir/ritonavir (ATV/r) and 66 with standard triple therapy were analyzed. A comparable virological efficacy between groups was found after 48 weeks (87.5% vs. 80.3% of HIV undetectability, p = 0.37, MVC + ATV/r and triple therapy groups, respectively). The CD4 recovery after 48 weeks was similar and more than 200 cells/mm³ in both groups. No need of therapy changes or treatment discontinuations was observed in the MVC + ATV/r group. Effect on lipid profile, high-sensitivity C reactive protein, and β2-microglobulin was similar for both groups. Noteworthy, a significant increase of erythrocyte mean corpuscular volume was observed only in the triple therapy group. A nucleoside-sparing MVC-containing dual therapy showed similar immunovirological efficacy and tolerability than standard triple therapy in naive HIV-infected patients.

Switching to boosted protease inhibitor plus a second antiretroviral drug (dual therapy) for treatment simplification: a multicenter observational study

BACKGROUND

Aim of the study was to assess predictors of discontinuation/toxicity of boosted PI-based (PI/r) dual therapy (DT).

METHODS

Observational, retrospective switch study in patients successfully treated with triple drugs regimen. Patients switched to PI/r based DT [darunavir (DRV/r), lopinavir (LPV/r) or atazanavir (ATV/r)] plus a second drug: [raltegravir (RAL), maraviroc (MVC) etravirine (ETR), lamivudine (3TC) or tenofovir (TDF)] between 2009 and 2014 were included. The effect of each drug as well as other clinical and virological cofactors over treatment discontinuation (TD) was assessed using survival analysis.

RESULTS

Overall, 376 patients were included with mean follow-up of 73 weeks. The most commonly used drugs in DT were DRV/r (63.0 %) and RAL (53.7 %). TD was observed in 77 (20,4 %) patients: 38 (10,1 %) virological failure, 35 (9,3 %) toxicity/intolerance (4 deaths) and 4 (1 %) interruptions for patients decision. At Cox Model, adjusted by demographic and laboratory variables, DRV/r and ATV/r significantly reduced the likelihood of TD and longer treatment was associated with lower risk, while low CD4 count at baseline and number of previous regimens with a higher risk. Moreover, RAL and 3TC use were significantly associated with lower TD by toxicity.

CONCLUSIONS

In our clinical practice experience, switching virologically suppressed patients to PI/r based DT showed adequate safety and efficacy, so that it may be used in selected patients with specific medical needs.

Identification and Characterization of BMS-955176, a Second-Generation HIV-1 Maturation Inhibitor with Improved Potency, Antiviral Spectrum, and Gag Polymorphic Coverage

BMS-955176 is a second-generation human immunodeficiency virus type 1 (HIV-1) maturation inhibitor (MI). A first-generation MI, bevirimat, showed clinical efficacy in early-phase studies, but ∼50% of subjects had viruses with reduced susceptibility associated with naturally occurring polymorphisms in Gag near the site of MI action. MI potency was optimized using a panel of engineered reporter viruses containing site-directed polymorphic changes in Gag that reduce susceptibility to bevirimat (including V362I, V370A/M/Δ, and T371A/Δ), leading incrementally to the identification of BMS-955176. BMS-955176 exhibits potent activity (50% effective concentration [EC50], 3.9 ± 3.4 nM [mean ± standard deviation]) toward a library (n = 87) of gag/pr recombinant viruses representing 96.5% of subtype B polymorphic Gag diversity near the CA/SP1 cleavage site. BMS-955176 exhibited a median EC50 of 21 nM toward a library of subtype B clinical isolates assayed in peripheral blood mononuclear cells (PBMCs). Potent activity was maintained against a panel of reverse transcriptase, protease, and integrase inhibitor-resistant viruses, with EC50s similar to those for the wild-type virus. A 5.4-fold reduction in EC50 occurred in the presence of 40% human serum plus 27 mg/ml of human serum albumin (HSA), which corresponded well to an in vitro measurement of 86% human serum binding. Time-of-addition and pseudotype reporter virus studies confirm a mechanism of action for the compound that occurs late in the virus replication cycle. BMS-955176 inhibits HIV-1 protease cleavage at the CA/SP1 junction within Gag in virus-like particles (VLPs) and in HIV-1-infected cells, and it binds reversibly and with high affinity to assembled Gag in purified HIV-1 VLPs. Finally, in vitro combination studies showed no antagonistic interactions with representative antiretrovirals (ARVs) of other mechanistic classes. In conclusion, BMS-955176 is a second-generation MI with potent in vitro anti-HIV-1 activity and a greatly improved preclinical profile compared to that of bevirimat.

Once-daily maraviroc versus tenofovir/emtricitabine each combined with darunavir/ritonavir for initial HIV-1 treatment

Objective:

The aim of this study was to evaluate the efficacy of maraviroc along with darunavir/ritonavir, all once daily, for the treatment of antiretroviral-naive HIV-1 infected individuals.

Design:

MODERN was a multicentre, double-blind, noninferiority, phase III study in HIV-1 infected, antiretroviral-naive adults with plasma HIV-1 RNA at least 1000 copies/ml and no evidence of reduced susceptibility to study drugs.

Methods:

At screening, participants were randomized 1 : 1 to undergo either genotypic or phenotypic tropism testing. Participants with CCR5-tropic HIV-1 were randomized 1 : 1 to receive maraviroc 150 mg once daily or tenofovir/emtricitabine once daily each with darunavir/ritonavir once daily for 96 weeks. The primary endpoint was the proportion of participants with HIV-1 RNA less than 50 copies/ml (Food and Drug Administration snapshot algorithm) at Week 48. A substudy evaluated bone mineral density, body fat distribution and serum bone turnover markers.

Results:

Seven hundred and ninety-seven participants were dosed (maraviroc, n = 396; tenofovir/emtricitabine, n = 401). The Data Monitoring Committee recommended early study termination due to inferior efficacy in the maraviroc group. At Week 48, the proportion of participants with HIV-1 RNA less than 50 copies/ml was 77.3% for maraviroc and 86.8% for tenofovir/emtricitabine [difference of −9.54% (95% confidence interval: −14.83 to −4.24)]. More maraviroc participants discontinued for lack of efficacy, which was not associated with non-R5 tropism or resistance. Discontinuations for adverse events, Category C events, Grade 3/4 adverse events and laboratory abnormalities were similar between groups.

Conclusion:

A once-daily nucleos(t)ide-sparing two-drug regimen of maraviroc and darunavir/ritonavir was inferior to a three-drug regimen of tenofovir/emtricitabine and darunavir/ritonavir in antiretroviral-naive adults.

Brief Report: Switch to Ritonavir-Boosted Atazanavir Plus Raltegravir in Virologically Suppressed Patients With HIV-1 Infection: A Randomized Pilot Study

This open-label, multinational, pilot study randomized (1:2 ratio) adults with HIV-1 RNA <40 copies per milliliter and nucleos(t)ide-related safety/tolerability issues to switch to ritonavir-boosted atazanavir (ATV/r) plus tenofovir disoproxil fumarate/emtricitabine (n = 37) or the nucleos(t)ide reverse transcriptase inhibitor-sparing regimen of ATV/r plus raltegravir (RAL) (n = 72). At 24 weeks, 35/37 (94.6%) and 58/72 (80.6%) of patients, respectively, maintained virological suppression, the primary endpoint, and 1 (2.7%) and 7 (9.7%), respectively, experienced virological rebound. Corresponding 48-week proportions were 86.5%, 69.4%, 2.7%, and 12.5%, respectively. Adherence was lower and treatment discontinuation was higher with ATV/r+RAL. In conclusion, switching to ATV/r+RAL resulted in a higher virological rebound rate than switching to ATV/r plus tenofovir disoproxil fumarate/emtricitabine.

Dual Therapy Treatment Strategies for the Management of Patients Infected with HIV: A Systematic Review of Current Evidence in ARV-Naive or ARV-Experienced, Virologically Suppressed Patients

OBJECTIVE

We reviewed the current literature regarding antiretroviral (ARV)-sparing therapy strategies to determine whether these novel regimens can be considered appropriate alternatives to standard regimens for the initial treatment of ARV-naive patients or as switch therapy for those patients with virologically suppressed HIV infection.

METHODS

A search for studies related to HIV dual therapy published from January 2000 through April 2014 was performed using Biosis, Derwent Drug File, Embase, International Pharmaceutical Abstracts, Medline, Pascal, SciSearch, and TOXNET databases; seven major trial registries, and the abstracts of major conferences. Using predetermined criteria for inclusion, an expert review committee critically reviewed and qualitatively evaluated all identified trials for efficacy and safety results and potential limitations.

RESULTS

Sixteen studies of dual therapy regimens were critiqued for the ARV-naive population. Studies of a protease inhibitor/ritonavir in combination with the integrase inhibitor raltegravir or the nucleoside reverse transcriptase inhibitor lamivudine provided the most definitive evidence supporting a role for dual therapy. In particular, lopinavir/ritonavir or darunavir/ritonavir combined with raltegravir and lopinavir/ritonavir combined with lamivudine demonstrated noninferiority to standard of care triple therapy after 48 weeks of treatment. Thirteen trials were critiqued in ARV-experienced, virologically suppressed patients. The virologic efficacy outcomes were mixed. Although overall data regarding toxicity are limited, when compared with standard triple therapy, certain dual therapy regimens may offer advantages in renal function, bone mineral density, and limb fat changes; however, some dual combinations may elevate lipid or bilirubin levels.

CONCLUSIONS

The potential benefits of dual therapy regimens include reduced toxicity, improved tolerability and adherence, and reduced cost. Although the data reviewed here provide valuable insights into the effectiveness and tolerability of dual therapy regimens, it remains unclear whether these potential benefits can be maintained long-term. Appropriately powered studies with longer follow-up periods are needed to more definitively assess potential toxicity reduction advantages with dual therapy.

Dual Raltegravir-Darunavir/Ritonavir Combination in Virologically Suppressed HIV-1-Infected Patients on Antiretroviral Therapy Including a Ritonavir-Boosted Protease Inhibitor Plus Two Nucleoside/Nucleotide Reverse Transcriptase Inhibitors

BACKGROUND

Nucleoside reverse transcriptase inhibitor (NRTI)-sparing antiretroviral therapies may be useful in HIV-infected patients with resistance or intolerance to this class.

METHODS

We performed an observational study of patients on suppressive antiretroviral therapy containing two NRTIs plus one ritonavir-boosted protease inhibitor who switched to a dual regimen containing raltegravir (400 mg twice daily) and darunavir/ritonavir (800/100 mg once daily) and were followed-up for 48 weeks.

RESULTS

As a whole, 82 patients were enrolled. Mean duration of current regimen was 4.6 years and mean duration of plasma HIV RNA < 50 copies/mL before the switch was 46.2 months. Reason for simplification was toxicity in 76 patients and resistance to NRTIs in 13. After switching, the percentage of patients with HIV RNA < 50 copies/mL at week 48 was 92.7% in the intent-to-treat-exposed analysis and 97.6% in the per-protocol analysis. The switch led to a significant reduction in the mean triglyceride value (-85.2 mg/dL), in the prevalence of tubular proteinuria (-56%) and in the mean level of interleukin-6 (-0.94 pg/mL), with a significant increase in the mean phosphoremia (+0.58 mg/dL). Mean trough concentrations of both raltegravir and darunavir were within the therapeutic range. Two patients (2.4%) had virological failure due to suboptimal adherence and 4 subjects (4.9%) discontinued treatment due to adverse events, but no patients experienced Grade 3 or 4 adverse events.

CONCLUSION

In our study, simplification to a dual therapy containing raltegravir plus darunavir/ritonavir after 48 weeks maintained viral suppression in more than 90% of patients and showed a good tolerability with a favourable effect on proteinuria, ipophosphoremia, and lipid metabolism.

Antiretroviral resistance at virological failure in the NEAT 001/ANRS 143 trial: raltegravir plus darunavir/ritonavir or tenofovir/emtricitabine plus darunavir/ritonavir as first-line ART

OBJECTIVES

To describe the pattern of drug resistance at virological failure in the NEAT001/ANRS143 trial (first-line treatment with ritonavir-boosted darunavir plus either tenofovir/emtricitabine or raltegravir).

METHODS

Genotypic testing was performed at baseline for reverse transcriptase (RT) and protease genes and for RT, protease and integrase (IN) genes for patients with a confirmed viral load (VL) >50 copies/mL or any single VL >500 copies/mL during or after week 32.

RESULTS

A resistance test was obtained for 110/805 (13.7%) randomized participants qualifying for resistance analysis (61/401 of participants in the raltegravir arm and 49/404 of participants in the tenofovir/emtricitabine arm). No resistance-associated mutation (RAM) was observed in the tenofovir/emtricitabine plus darunavir/ritonavir arm, and all further analyses were limited to the raltegravir plus darunavir arm. In this group, 15/55 (27.3%) participants had viruses with IN RAMs (12 N155H alone, 1 N155H + Q148R, 1 F121Y and 1 Y143C), 2/53 (3.8%) with nucleotide analogue RT inhibitor RAMs (K65R, M41L) and 1/57 (1.8%) with primary protease RAM (L76V). The frequency of IN mutations at failure was significantly associated with baseline VL: 7.1% for a VL of <100,000 copies/mL, 25.0% for a VL of ≥100,000 copies/mL and <500,000 copies/mL and 53.8% for a VL of ≥500,000 copies/mL (PTREND = 0.007). Of note, 4/15 participants with IN RAM had a VL < 200 copies/mL at time of testing.

CONCLUSIONS

In the NEAT001/ANRS143 trial, there was no RAM at virological failure in the standard tenofovir/emtricitabine plus darunavir/ritonavir regimen, contrasting with a rate of 29.5% (mostly IN mutations) in the raltegravir plus darunavir/ritonavir NRTI-sparing regimen. The cumulative risk of IN RAM after 96 weeks of follow-up in participants initiating ART with raltegravir plus darunavir/ritonavir was 3.9%.

Comparison of the pharmacokinetics of raltegravir given at 2 doses of 400 mg by swallowing versus one dose of 800 mg by chewing in healthy volunteers: a randomized, open-label, 2-period, single-dose, crossover phase 1 study

BACKGROUND

The pharmacokinetics of raltegravir (RAL) in HIV patients is characterized by high interindividual and intraindividual variability. We documented previously that HIV patients taking RAL at 400 mg bid by chewing the tablets had significantly higher drug absorption and reduced pharmacokinetic variability than patients taking the drug by swallowing the tablets. This study extends our previous findings.

METHODS

An open-label, 2-period crossover study compared the pharmacokinetics of 2 doses of RAL given at 400 mg every 12 hours (that mimics a bid administration) by swallowing with 1 dose of 800 mg (that mimics a qd administration) by chewing the tablets in 12 healthy volunteers. RAL plasma concentrations were measured by a chromatographic method coupled with mass spectrometry.

RESULTS

Subjects taking RAL by chewing had significantly higher drug exposure (RAL area under the curve[AUC](0-24): 40722 ± 14843 versus 21753 ± 12229 ng · h/mL, P < 0.0001) and reduced pharmacokinetic variability compared with those taking the drug by swallowing the whole tablet, with no difference in the minimum RAL concentrations (RAL C(min): 36 ± 23 versus 43 ± 23 ng/mL, P = 0.298). Subjects taking RAL by chewing the tablets had significantly higher drug absorption and reduced pharmacokinetic variability compared with those taking the drug by swallowing. No differences were observed in the minimum RAL concentrations.

CONCLUSIONS

RAL at 800 mg once daily by chewing the tablets may represent a novel therapeutic option for the treatment of HIV being associated with higher drug absorption, reduced pharmacokinetic variability, and potentially better compliance compared with patients swallowing the 400-mg bid intact tablets.

Ageing with HIV: a multidisciplinary review

INTRODUCTION

After the introduction of highly active antiretroviral treatment, the course of HIV infection turned into a chronic disease and most of HIV-positive patients will soon be over 50 years old.

MATERIAL AND METHODS

This paper reviews the multiple aspects that physicians have to face while taking care of HIV-positive ageing patients including the definitions of frailty and the prevalence and risk factors of concomitant diseases. From a therapeutic point of view pharmacokinetic changes and antiretroviral-specific toxicities associated with ageing are discussed; finally therapeutic approaches to frailty are reviewed both in HIV-positive and negative patients.

CONCLUSION AND DISCUSSION

We conclude by suggesting that the combined use of drugs with the least toxicity potential and the promotion of healthy behaviours (including appropriate nutrition and exercise) might be the best practice for ageing HIV-positive subjects.

Ritonavir-boosted darunavir combined with raltegravir or tenofovir-emtricitabine in antiretroviral-naive adults infected with HIV-1: 96 week results from the NEAT001/ANRS143 randomised non-inferiority trial

BACKGROUND

Standard first-line antiretroviral therapy for HIV-1 infection includes two nucleoside or nucleotide reverse transcriptase inhibitors (NtRTIs), but these drugs have limitations. We assessed the 96 week efficacy and safety of an NtRTI-sparing regimen.

METHODS

Between August, 2010, and September, 2011, we enrolled treatment-naive adults into this randomised, open-label, non-inferiority trial in treatment-naive adults in 15 European countries. The composite primary outcome was change to randomised treatment before week 32 because of insufficient virological response, no virological response by week 32, HIV-1 RNA concentration 50 copies per mL or higher at any time after week 32; death from any cause; any new or recurrent AIDS event; or any serious non-AIDS event. Patients were randomised in a 1:1 ratio to receive oral treatment with 400 mg raltegravir twice daily plus 800 mg darunavir and 100 mg ritonavir once daily (NtRTI-sparing regimen) or tenofovir-emtricitabine in a 245 mg and 200 mg fixed-dose combination once daily, plus 800 mg darunavir and 100 mg ritonavir once daily (standard regimen). This trial was registered with ClinicalTrials.gov, number NCT01066962.

FINDINGS

Of 805 patients enrolled, 401 received the NtRTI-sparing regimen and 404 the standard regimen, with median follow-up of 123 weeks (IQR 112-133). Treatment failure was seen in 77 (19%) in the NtRTI-sparing group and 61 (15%) in the standard group. Kaplan-Meier estimated proportions of treatment failure by week 96 were 17·8% and 13·8%, respectively (difference 4·0%, 95% CI -0·8 to 8·8). The frequency of serious or treatment-modifying adverse events were similar (10·2 vs 8·3 per 100 person-years and 3·9 vs 4·2 per 100 person-years, respectively).

INTERPRETATION

Our NtRTI-sparing regimen was non-inferior to standard treatment and represents a treatment option for patients with CD4 cell counts higher than 200 cells per μL.

FUNDING

European Union Sixth Framework Programme, Inserm-ANRS, Gilead Sciences, Janssen Pharmaceuticals, Merck Laboratories.

Muscle symptoms and creatine phosphokinase elevations in patients receiving raltegravir in clinical practice: Results from the SCOLTA project long-term surveillance

Muscle alterations ranging from asymptomatic creatine phosphokinase (CPK) increases to rhabdomyolysis and central nervous system (CNS) symptoms have been reported in patients receiving raltegravir. Muscle symptoms and CPK increases were investigated in a cohort of HIV-infected patients receiving raltegravir-based antiretroviral therapy, and possible associated predictors were evaluated. The SCOLTA Project is a prospective, observational, multicentre study created to assess the incidence of adverse events in patients receiving new antiretroviral drugs in clinical practice. In total, 496 HIV-infected patients were enrolled [333 (67.1%) male]. CDC stage was C in 196 patients (39.5%). Mean age at enrolment was 45.9 ± 9.3 years. Median follow-up was 21 months. Twenty-six patients (5.2%) reported muscle symptoms (16 muscle pain and 17 weakness; 7 had both). Of 342 patients with normal baseline CPK values, 72 (21.1%) had a CPK increase. Seven patients (1.4%) discontinued raltegravir because of muscular events (three for muscle pain/weakness and four CPK increases). No cases of rhabdomyolysis were observed. Patients with muscle symptoms were more frequently receiving in their regimen than those not receiving atazanavir (P=0.04) and were more likely to also report CNS symptoms (P<0.0001). Significant predictors of muscle symptoms were CNS symptoms and use of atazanavir. Female sex was associated with a reduced risk of CPK increase. In conclusion, muscle symptoms and CPK elevations occurred frequently and caused most discontinuations due to adverse events. Their monitoring in patients receiving raltegravir should be considered, especially when co-administered with atazanavir or when CNS symptoms are also present.

Clinical practice guideline for the management of chronic kidney disease in patients infected with HIV: 2014 update by the HIV Medicine Association of the Infectious Diseases Society of America

It is important to realize that guidelines cannot always account for individual variation among patients. They are not intended to supplant physician judgment with respect to particular patients or special clinical situations. IDSA considers adherence to these guidelines to be voluntary, with the ultimate determination regarding their application to be made by the physician in the light of each patient's individual circumstances.

Efficacy and safety of darunavir/ritonavir plus etravirine dual regimen in antiretroviral therapy-experienced patients: a multicenter clinical experience

OBJECTIVES

To assess the outcome of a dual regimen combining darunavir/ritonavir plus etravirine in a cohort of antiretroviral therapy (ART)-experienced patients.

METHODS

A retrospective analysis was performed on all ART-experienced patients starting a darunavir/ritonavir plus etravirine regimen at the 3 clinics. Patients were stratified according to HIV RNA detectability (≥ 40 copies/mL) at baseline. Two efficacy endpoints were evaluated by Kaplan-Meier and Cox multivariable models: virological failure (confirmed HIV RNA ≥ 40 copies/mL after 6 months) and therapeutic failure (including virological failure and treatment discontinuation for any reason).

RESULTS

Sixty-eight patients were included in the study. They had a median of 10.8 years on ART and 5 previous ART regimens; 61.3% showed primary protease inhibitor (PI) mutations and 70% showed previous non-nucleoside reverse transcriptase inhibitor (NNRTI) exposure. HIV RNA was detectable in 34 (50%) patients. The median observation period was 21 (interquartile range [IQR], 11.9-25.1) months. After 24 months, 75.1% of the patients were still on the study regimen and 88.8% remained free from virological failure. Although a higher therapeutic failure rate was reported in patients with detectable viremia at baseline, only the immunological status revealed an independent predictive role. No differences in virological failure were observed according to HIV RNA detectability at baseline; a higher number of previous ART regimens was the only predictor. Discontinuation due to adverse events occurred in 5.9%.

CONCLUSIONS

Darunavir/ritonavir plus etravirine regimen proved virological efficacy and safety in heavily pretreated patients with a high rate of virological success, even in patients who switched during virological failure.

Efficacy and safety of switching to raltegravir plus atazanavir dual therapy in pretreated HIV-1-infected patients over 144 weeks: a cohort study

BACKGROUND

To decrease drug burden among HIV-1-positive adults, we need a new gold standard for antiretroviral therapy maintenance strategies.

METHODS

This retrospective study aimed to assess efficacy in maintenance strategy of atazanavir (ATV) and raltegravir (RAL) dual therapy. The proportion of patients with HIV-1 RNA < 40 copies/ml at specific time points was recorded. Immunological response, safety, and pharmacokinetics were assessed.

RESULTS

Overall, 39 patients were switched to a RAL/ATV (n = 32) or RAL/ATV plus ritonavir (n = 7) regimen. Almost all patients (95%) received RAL twice daily. Most patients (70%) received a 400 mg ATV dosing per day, once (26%) or twice daily (44%). The percentages of virological success at weeks 24, 48, 96, and 144 were 92% (95% confidence interval (CI), 83-10), 86% (95% CI, 74-98), 70% (95% CI, 52-88), and 63% (95% CI, 42-84), respectively. Overall, 12 (31%) patients stopped dual therapy: 7 patients because of adverse events, mostly clinical myositis (n = 3). Confirmed virological failure occurred in three patients; two of them developed RAL resistance patterns. A significant increase in the CD4+/CD8 + T-cell ratio was observed at week 48 (p < 0.005). Only grade 1-2 adverse events were observed. Trough plasma levels presented a wide variability. Suggested trough concentrations were achieved in 79% and 94% of patients for ATV and RAL, respectively. An unboosted 400 mg per day ATV dosing seemed to be appropriate, regarding the targeted levels achieved and the lack of grade 3 or 4 hyperbilirubinemia.

CONCLUSIONS

We demonstrated, on a 3-year follow-up, the efficacy and safety of RAL plus ATV maintenance dual therapy.

Low-frequency NNRTI-resistant HIV-1 variants and relationship to mutational load in antiretroviral-naïve subjects

Low-frequency HIV variants possessing resistance mutations against non‑nucleoside reverse transcriptase inhibitors (NNRTI), especially at HIV reverse transcriptase (RT) amino acid (aa) positions K103 and Y181, have been shown to adversely affect treatment response. Therapeutic failure correlates with both the mutant viral variant frequency and the mutational load. We determined the prevalence of NNRTI resistance mutations at several RT aa positions in viruses from 204 antiretroviral (ARV)-naïve HIV-infected individuals using deep sequencing, and examined the relationship between mutant variant frequency and mutational load for those variants. Deep sequencing to ≥0.4% levels found variants with major NNRTI-resistance mutations having a Stanford-HIVdb algorithm value ≥30 for efavirenz and/or nevirapine in 52/204 (25.5%) ARV-naïve HIV-infected persons. Eighteen different major NNRTI mutations were identified at 11 different positions, with the majority of variants being at frequency >1%. The frequency of these variants correlated strongly with the mutational load, but this correlation weakened at low frequencies. Deep sequencing detected additional major NNRTI-resistant viral variants in treatment-naïve HIV-infected individuals. Our study suggests the significance of screening for mutations at all RT aa positions (in addition to K103 and Y181) to estimate the true burden of pre-treatment NNRTI-resistance. An important finding was that variants at low frequency had a wide range of mutational loads (>100-fold) suggesting that frequency alone may underestimate the impact of specific NNRTI-resistant variants. We recommend further evaluation of all low-frequency NNRTI-drug resistant variants with special attention given to the impact of mutational loads of these variants on treatment outcomes.

The RADAR study: week 48 safety and efficacy of RAltegravir combined with boosted DARunavir compared to tenofovir/emtricitabine combined with boosted darunavir in antiretroviral-naive patients. Impact on bone health

Background

NRTI-sparing regimens may avoid long-term mitochondrial, bone and renal toxicities and maintain viral suppression.

Methods

In the RADAR study, 85 antiretroviral-naïve HIV-infected patients were randomized to receive either raltegravir (RAL) (n = 42) or tenofovir/emtricitabine (TDF/FTC) (n = 43), each with ritonavir-boosted darunavir (DRV/r). Virologic efficacy was assessed at weeks 24 and 48. Bone mineral density (BMD) was assessed by dual energy X-ray absorptiometry (DXA) scan at baseline and week 48, and bone turnover markers (BTM) assessed at weeks 0, 16 and 48.

Results

Using an intention-to-treat analysis, 62.5% of RAL subjects and 83.7% of TDF/FTC subjects were responders (VL<48 copies/mL) at week 48 (p = 0.045; chi-square test). The proportions of patients achieving VL<200 copies/mL were similar: 72.5% and 86.0% (p = 0.175). Premature treatment discontinuation was the main cause for failure. No treatment-emergent resistance was observed. Changes from baseline in RAL vs. TDF/FTC for CD4⁺ (+199 vs. +216 cells/µL, p = 0.63), total cholesterol/HDL (−0.25 vs. −0.71 mg/dL (p = 0.270), and eGFR (−4.4 vs. −7.9 ml/min, p = 0.44) were comparable between groups. Changes in subtotal BMD to week 48 were: +9.2 with RAL vs. −7 g/cm² with TDF/FTC (p = 0.002). Mean CTX changes were +0.04 vs. +0.24 ng/mL (p = 0.001), and mean P1NP changes were +3.59 vs. +30.09 ng/mL (p = 0.023). BTM changes at week 16 predicted change in BMD by week 48 (R = −0.394, p = 0.003 for CTX; and R = −0.477, p<0.001 for P1NP).

Conclusion

The NRTI-sparing regimen RAL+DRV/r did not achieve similar week 48 virologic efficacy compared with TDF/FTC+DRV/r, but was better with regard to markers of bone health.

Trial Registration

ClinicalTrials.gov NCT 00677300

Maintenance of virologic efficacy and decrease in levels of β2-microglobulin, soluble CD40L and soluble CD14 after switching previously treated HIV-infected patients to an NRTI-sparing dual therapy

Novel strategies are necessary to decrease inflammatory parameters in successfully treated HIV-infected patients. Our aim was to evaluate the maintenance of viral suppression and potential changes in inflammatory, immune-activation and coagulation biomarkers in virologically suppressed HIV-infected patients switched to a nucleoside reverse transcriptase inhibitor-sparing (NRTI) and maraviroc (MVC)-containing combined antiretroviral therapy (cART). Fifty-eight HIV-infected patients were observed after their treatment regimens were changed to MVC 150mg/once daily plus ritonavir-boosted protease inhibitor therapy. Activation-, inflammation- and coagulation-associated biomarkers and mitochondrial (mt)DNA were analyzed after a median of 24weeks of follow-up. We observed that after changing to an NRTI-sparing regimen, 96.6% of HIV-patients on viral suppressive cART maintained viral suppression and their CD4+ T cell counts did not change significantly (median of 31weeks of follow-up). This cART switch reduced soluble CD40 ligand (p=0.002), beta-2 microglobulin (p=0.025), and soluble CD14 (p=0.009) in patients with higher baseline levels of these inflammation biomarkers after a median of 24weeks of follow-up. The results of our study show that changing to NRTI-sparing dual therapy decreased the levels of inflammatory biomarkers and maintained the immune-virologic efficacy. The potential benefits of this regimen warrant further investigation to uncover the association of this therapy with the potential decrease in the morbidity and mortality of HIV-infected patients from non-AIDS-defining illnesses.

Switch strategies in antiretroviral therapy regimens

Despite great advances in antiretroviral therapy in the last decade, several limitations still remain such as adverse effects, lack of adherence and drug-drug interactions. Switching antiretroviral therapy in stable, virologically suppressed patients with the aim of improving tolerability and convenience is an expanding strategy in clinical practice. Several factors need to be taken into consideration when switching a suppressive regimen, such as previous virologic failure, genetic barrier of the new regimen, prior duration of virologic suppression and expected level of adherence. The most frequently used strategies include reductions in the number of pills, drugs or doses. Although switching strategies may be useful, not all the regimens used in clinical practice are based on data from randomized clinical trials and some may not be the best option for certain patients; therefore, therapy should be individualized taking into consideration available information as well as patient and drug characteristics.